PLATE HEAT EXCHANGER

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0096418, filed on Jul. 22, 2024, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

Field

The present disclosure relates to a plate heat exchanger.

Description of Related Art

An air conditioner refers to an apparatus that cools and heats an indoor space via the compression, condensation, expansion, and evaporation processes of refrigerant.

When the air conditioner heats the indoor space, an indoor heat exchanger disposed in an indoor unit acts as a condenser through which high-temperature and high-pressure refrigerant passes. When the air conditioner heats the indoor space, an outdoor heat exchanger disposed in an outdoor unit acts as an evaporator through which low-temperature and low-pressure refrigerant passes.

On the contrary, when the air conditioner cools the indoor space, the indoor heat exchanger acts as an evaporator. When the air conditioner cools the indoor space, the outdoor heat exchanger acts as a condenser.

In this regard, each of the indoor and outdoor heat exchangers is embodied as a plate heat exchanger.

The plate heat exchanger has an advantage of high heat transfer efficiency between fluids with different temperatures, for example, high temperature first fluid (e.g., water, etc.) and low temperature second fluid (e.g., refrigerant, etc.).

However, the plate heat exchanger has following problems.

In the plate heat exchanger, in an evaporation process in which the low temperature second fluid (e.g., refrigerant, etc.) takes heat from the high temperature first fluid (e.g., water, etc.), the first fluid may freeze near a second fluid inlet and a second fluid outlet where the second fluid flows due to the low temperature of the second fluid. As a result, the frozen area may be broken and thus. there is a problem in which the plate heat exchanger is damaged.

In particular, this problem may often occur in a non-fluid channel area, (i.e., an area where the first fluid does not flow and stagnates, in an area around the second fluid inlet and second fluid outlet where the low temperature second fluid flows.

For example, a dead zone where no fluid flows is formed in the non-fluid channel area of the plate heat exchanger. The dead zone is mainly formed around the refrigerant, (i.e., the second fluid inlet and the second fluid outlet, and is configured to increase pressure resistance, performance, and efficiency. An area around the dead zone may be brazed.

However, when a brazing defect occurs in the area around the dead zone, a gap may occur between the dead zone and the first fluid channel through which the first fluid (i.e., water flows. As a result, when the first fluid flows into the dead zone where there is no fluid flow, the first fluid may freeze in the dead zone due to the low temperature of the second fluid flowing around the dead zone. Thus, the dead zone may be broken and as a result, the plate heat exchanger may be damaged, thereby causing deterioration of quality reliability.

Therefore, in order to reduce the possibility at which the plate heat exchanger is frozen and broken and to improve quality reliability, a technical solution capable of inspecting dead zone fluid-tightness is required.

In a prior art document related to the present disclosure, WO 2020-188690 A1 (hereinafter, prior art document 1) discloses a plate heat exchanger and a heat pump device equipped with the same.

The plate heat exchanger disclosed in prior art document 1 relates to a technology capable of inspecting in advance whether water flows into a cavity (i.e., dead zone) and remains therein, and the water in the cavity freezes and damages the heat-transfer plate.

However, the technology of the prior art document 1 may identify whether water does not invade into the cavity (i.e., dead zone) due to poor brazing, but has a disadvantage in that it cannot prevent the inflow of outside air thereto after this identification work. In other words, there is a problem that moisture contained in the outside air may invade therein after the inspection, so there is a possibility of freezing or breaking the plate heat exchanger.

Furthermore, the prior art document 1 has a heat-transfer plate with a thin brazing thickness, more specifically, a heat-transfer plate flange with a communication hole formed therein. A location of this communication hole is a position where the outside air may directly contact the communication hole. Thus, there is a serious problem that the fluid may directly leak out when the heat-transfer plate which is weak in strength and small in thickness, corrodes.

A further prior art document KR 10-1314906 B1 (hereinafter, prior art document 2) related to the present disclosure discloses a plate heat exchanger and a manufacturing method thereof.

The plate heat exchanger disclosed in the prior art document 2 only suggests a scheme for improving heat exchange efficiency by improving the fluid channel, and does not suggest any scheme for preventing the freezing problem due to freezing of water (i.e., first fluid) in the surrounding area around the area where the refrigerant (i.e., second fluid) flows.

Furthermore, the prior art document 2 does not disclose inspecting of the fluid-tightness of the dead zone to prevent the freezing and rupture of the dead zone in advance due to water (i.e., first fluid flowing into the dead zone due to poor brazing.

A still further prior art document KR 10-2443308 B1 (hereinafter, prior art document 3) related to the present disclosure discloses a freeze-prevention type plate heat exchanger.

In the freeze-prevention plate heat exchanger disclosed in the prior art document 3, corner areas of the stacked heat-transfer plates are welded and joined with each other with a joining reinforcement portion to increase the joining strength, and a structure that may improve the fluidity of the fluid or refrigerant in the corner area of each heat-transfer plate is provided, thereby preventing the plate from being broken due to the freezing.

However, the prior document 3 does not provide any information on pre-inspecting the fluid-tightness of the dead zone before shipment by injecting gas into a dead zone hole located in the corner area to inspect for the welding joining defect after welding the corner area of the heat-transfer plate.

Prior art literature: Patent literature: Prior art document 1: WO 2020-188690 A1; Prior art document 2: KR 10-1314906 B1; and Prior art document 3: KR 10-2443308 B1

SUMMARY

A purpose of the present disclosure is to provide a plate heat exchanger in which a cover hole is defined in a cover to inject external gas through the cover hole, and a dead zone hole connected to the cover hole is defined in a dead zone of a heat-transfer plate such that the gas is injected into the dead zone through the cover hole, and thus, whether gas flows between the dead zone and a fluid channel through which the first fluid (i.e., water) flows, thereby safely and quickly inspecting the fluid-tightness of the dead zone after the brazing.

Another purpose of the present disclosure is to provide a plate heat exchanger in which after the fluid-tightness of the dead zone has been inspected, the cover hole is sealed with a sealing, thereby preventing moisture contained in the outside air from flowing into the heat-transfer plate or the dead zone, thereby preventing freezing and breakage caused by the external moisture.

Still another purpose of the present disclosure is to provide a plate heat exchanger in which a hole into which the outside gas is injected is not defined in the heat-transfer plate having a small thickness and a weak strength but the cover hole which the outside gas is injected is defined in the cover thicker and stronger than the heat-transfer plate, thereby providing excellent workability of the hole into which the gas is injected, and various sealing means are available, and the problem of fluid being exposed to the outside due to corrosion of the heat-transfer plate may be prevented.

Purposes according to the present disclosure are not limited to the above-mentioned purpose. Other purposes and advantages according to the present disclosure that are not mentioned may be understood based on following descriptions, and may be more clearly understood based on embodiments according to the present disclosure. Further, it will be easily understood that the purposes and advantages according to the present disclosure may be realized using means shown in the claims and combinations thereof.

A plate heat exchanger according to one aspect of the present disclosure includes a heat-transfer plate stack, a first cover, and a second cover, wherein a cover hole is defined in the second cover.

The plate heat exchanger according to some embodiments may receive gas from the outside through the cover hole defined in the second cover.

Heat-transfer plates may be stacked with each other to form the heat-transfer plate stack which may be received between the first and second covers.

A dead zone hole may be positioned in and extend through a dead zone formed in the heat-transfer plate.

The inspection gas may be injected into the dead zone from the outside through the cover hole. The injected gas may flow through the dead zone hole connected to the cover hole. Accordingly, the fluid-tightness between the dead zone and the fluid channel through which water (i.e., the first fluid) flows after the brazing joining may be inspected, and the brazing joining defect may be easily inspected before product shipment.

The plate heat exchanger includes the heat-transfer plate stack, the first cover, and the second cover.

The heat-transfer plate stack may include a plurality of heat-transfer plates stacked with each other, wherein the plurality of heat-transfer plates have respective heat-transfer areas in and along which first fluid and second fluid having a lower temperature than a temperature of the first fluid flow such that the first and second fluids exchange heat with each other.

The first cover may be coupled to one surface of the heat-transfer plate stack. The first cover may be configured to allow each of the first and second fluids to flow into the heat-transfer plate stack from an outside out of the plate heat exchanger therethrough and to flow out of the heat-transfer plate stack into the outside therethrough.

The second cover may be coupled to the other surface opposite to one surface of the heat-transfer plate stack.

According to some embodiments, the heat-transfer plate stack may include a first heat-transfer plate and a second heat-transfer plate.

The first heat-transfer plate may have a first heat-transfer area in which a first fluid channel in which the first fluid flows is formed.

The at least one second heat-transfer plate and the at least one first heat-transfer plate are alternately stacked with each other and are joined to each other. The second heat-transfer plate may have a second heat-transfer area in which a second fluid channel in which the second fluid flows is formed.

Each of the first and second heat-transfer plates may have a dead zone positioned in a non-fluid channel area outside each of the first and second heat-transfer areas. Each of the first and second fluids is prevented from flowing into the dead zone.

The second cover may have a cover hole defined therein through which gas is injected from the outside into the dead zone.

The dead zone may have a dead zone hole defined therein that communicates with the cover hole. The dead zone hole formed in the dead zone of the heat-transfer plate may allow the gas for inspection injected into the cover hole to be introduced into the dead zone therethrough. Accordingly, according to the present disclosure, the fluid-tightness of the dead zone may be inspected using the cover hole and the dead zone hole.

According to some embodiments, the first cover may be configured to allow the first fluid from the outside into the heat-transfer plate stack therethrough and allow the first fluid subjected to the heat exchange to be discharged to the outside therethrough,

Further, the first cover may be configured to allow the second fluid from the outside into the heat-transfer plate stack therethrough and allow the second fluid subjected to the heat exchange to be discharged to the outside therethrough.

According to some embodiments, the cover hole may extend through the second cover in a thickness direction of the second cover.

According to some embodiments, the cover hole and the dead zone holes may overlap each other in a stacking direction of the first and second heat-transfer plates and the first and second covers, and communicate with each other. Accordingly, the gas injected through the cover hole may be quickly introduced into the dead zone through the dead zone hole, thereby reducing the inspection time.

According to some embodiments, the cover hole and the dead zone hole may have a circular shape with the same diameter.

According to some embodiments, the centers of the cover hole and the dead zone hole may coincide with each other. That is, the cover hole and the dead zone hole may be concentric with each other. Accordingly, the gas injected through the cover hole may be quickly introduced into the dead zone through the dead zone hole.

According to some embodiments, the cover hole and the dead zone holes may be concentric with each other, wherein a diameter of the cover hole may be larger than a diameter of each of the dead zone holes. Accordingly, gas injection through the cover hole having the large diameter may be facilitated. Furthermore, the second cover having the cover hole defined therein may have a strength greater and a larger thickness than those of the heat-transfer plate in which the dead zone hole is formed. For this reason, the diameter of the cover hole may be larger than the diameter of the dead zone hole.

According to some embodiments, each of the first and second heat-transfer plates may be made of a first material. The second cover may be made of a second material. The second material may have a greater strength than that of the first material. Accordingly, the formation of the hole for injecting gas is advantageous, and the cover hole is formed in the second cover having a strength greater than that of each of the first and second heat-transfer plates, such that the risk of the fluid flowing in the stack being exposed to the outside may be reduced.

According to some embodiments, each of the first and second heat-transfer plates may have a first thickness. The second cover may have a second thickness. The second thickness may be larger than the first thickness.

According to some embodiments, each of the first and second heat-transfer plates may be made of a SUS316L material. The second cover may be made of a SUS304 material. SUS304 has a relatively higher content of each of chromium and nickel than that in SUS316L and thus has excellent heat resistance, wear resistance, and weldability. On the other hand, SUS316L has a higher molybdenum content than that in SUS304, and thus has enhanced corrosion resistance, and thus is suitable for use in an environment with a high possibility of corrosion.

According to some embodiments, the second cover may have a thickness that is greater by 5 to 7 times than that of each of the first and second heat-transfer plates. Accordingly, when the hole that directly receives gas from the outside is defined in the cover, (i.e., the second cover), it is easy to shape the hole, and workability thereof is good. Further, the cover hole may be sealed using various sealing means, for example, a plug that is physically fastened thereto to block the hole, as well as in a sealing or welding scheme.

According to some embodiments, the cover hole may include a plurality of cover holes positioned at different positions, wherein the dead zone hole defined in the dead zone of each of the first and second heat-transfer plates may include a plurality of dead zone holes, wherein a number of the plurality of dead zone holes may be equal to a number of the plurality of cover holes, wherein corresponding one of the plurality of cover holes, corresponding one of the plurality of dead zone holes defined in the first heat-transfer plate, and corresponding one of the plurality of dead zone holes defined in the second heat-transfer plate may overlap each other in a stacking direction of the first and second heat-transfer plates and the first and second covers, and may communicate with each other.

According to some embodiments, the first cover may have a first fluid outside-communicating inlet defined therein through which the first fluid flows from the outside out of the first cover into the heat-transfer plate stack.

According to some embodiments, the first cover may further have a first fluid outside-communicating outlet defined therein through which the first fluid subjected to the heat exchange flows out of the heat-transfer plate stack to the outside out of the first cover.

According to some embodiments, the first cover may further have a second fluid outside-communicating inlet defined therein through which the second fluid flows from the outside out of the first cover into the heat-transfer plate stack.

According to some embodiments, the first cover may further have a second fluid outside-communicating outlet defined therein through which the second fluid subjected to the heat exchange flows out of the heat-transfer plate stack to the outside out of the first cover.

According to some embodiments, the first heat-transfer plate may have a first heat-transfer plate first fluid inlet defined therein and located at one end in a longitudinal direction of the first heat-transfer area and connected to the first fluid channel, wherein the first fluid flows into the first heat-transfer area through the first heat-transfer plate first fluid inlet.

According to some embodiments, the first heat-transfer plate may further have a first heat-transfer plate first fluid outlet defined therein and located at the other end in the longitudinal direction of the first heat-transfer area and connected to the first fluid channel, wherein the first fluid flows out of the first heat-transfer area through the first heat-transfer plate first fluid outlet.

According to some embodiments, the first heat-transfer plate may further have a first heat-transfer plate second fluid inlet defined therein and spaced apart from the first heat-transfer plate first fluid outlet in a width direction of the first heat-transfer area, wherein the first heat-transfer plate second fluid inlet does not communicate with the first fluid channel, wherein the second fluid flows into the first heat-transfer area through the first heat-transfer plate second fluid inlet.

According to some embodiments, the first heat-transfer plate may further have a first heat-transfer plate second fluid outlet defined therein and spaced apart from the first heat-transfer plate first fluid inlet in the width direction of the first heat-transfer area, wherein the first heat-transfer plate second fluid outlet does not communicate with the first fluid channel, wherein the second fluid flows out of the first heat-transfer area through the first heat-transfer plate second fluid outlet.

According to some embodiments, the dead zone hole of the first heat-transfer plate may extend through the dead zone located close to each of the first heat-transfer plate second fluid inlet and the first heat-transfer plate second fluid outlet in a thickness direction of the first heat-transfer plate.

According to some embodiments, the second heat-transfer plate may have a second heat-transfer plate second fluid inlet defined therein and located at the other end in a longitudinal direction of the second heat-transfer area and connected to the second fluid channel, wherein the second fluid flows into the second heat-transfer area through the second heat-transfer plate second fluid inlet.

According to some embodiments, the second heat-transfer plate may further have a second heat-transfer plate second fluid outlet defined therein and located at one end in the longitudinal direction of the second heat-transfer area and connected to the second fluid channel, wherein the second fluid flows out of the second heat-transfer area through the second heat-transfer plate second fluid outlet.

According to some embodiments, the second heat-transfer plate may further have a second heat-transfer plate first fluid inlet defined therein and spaced apart from the second heat-transfer plate second fluid outlet in a width direction of the second heat-transfer area, wherein the second heat-transfer plate first fluid inlet does not communicate with the second fluid channel, wherein the first fluid flows into the second heat-transfer area through the second heat-transfer plate first fluid inlet.

According to some embodiments, the second heat-transfer plate may further have a second heat-transfer plate first fluid outlet defined therein and spaced apart from the second heat-transfer plate second fluid inlet in the width direction of the second heat-transfer area, wherein the second heat-transfer plate first fluid outlet does not communicate with the second fluid channel, wherein the first fluid flows out of the second heat-transfer area through the second heat-transfer plate first fluid outlet.

According to some embodiments, the dead zone hole of the second heat-transfer plate may extend through the dead zone located close to each of the second heat-transfer plate second fluid inlet and the second heat-transfer plate second fluid outlet in a thickness direction of the second heat-transfer plate.

According to some embodiments, the first heat-transfer plate and the second heat-transfer plate may be stacked with each other such that the dead zone of the first heat-transfer plate and the dead zone of the second heat-transfer plate overlap each other in a stacking direction thereof.

According to some embodiments, the dead zone hole defined in the dead zone of the first heat-transfer plate and the dead zone hole defined in the dead zone of the second heat-transfer plate may overlap each other in the stacking direction and communicate with each other.

According to some embodiments, a first flange is disposed along an edge of the first heat-transfer plate. According to some embodiments, each corner of the first heat-transfer plate has a round shape, and the dead zone hole of the first heat-transfer plate is positioned close to each corner of the round shape, and is positioned close to a portion of the first flange surrounding a portion of the edge of the corner of the round shape.

According to some embodiments, a second flange is disposed along an edge of the second heat-transfer plate. According to some embodiments, each corner of the second heat-transfer plate has a round shape, and the dead zone hole of the second heat-transfer plate is positioned close to each corner of the round shape, and is positioned close to a portion of the second flange surrounding a portion of the edge of the corner of the round shape.

According to some embodiments, in fluid-tightness inspection of the dead zone, inspection gas is injected into the cover hole, and then, the injected gas flows into the dead zone through the dead zone hole, and then, whether the gas flows between the dead zone and the first fluid channel is checked, and the fluid-tightness of the dead zone is determined based on the check result. Thus, brazing joining between portions of the plates around the dead zones is defective, based on the fluid-tightness inspection result of the dead zone.

According to some embodiments, the plate heat exchanger may further comprise a plug, wherein after the fluid-tightness inspection of the dead zone has been completed, the plug is inserted into the cover hole to seal the cover hole to prevent external moisture from invading the cover hole.

According to some embodiments, the plate heat exchanger may further comprise a welding sealing, wherein after the fluid-tightness inspection of the dead zone has been completed, the cover hole is welded with a welding material to form the welding sealing to seal the cover hole to prevent external moisture from invading the cover hole.

According to some embodiments, the plate heat exchanger may further comprise a sealing material, wherein after the fluid-tightness inspection of the dead zone has been completed, the sealing material is injected into the cover hole to seal the cover hole to prevent external moisture from invading the cover hole.

According to another aspect of the present disclosure, a plate heat exchanger includes a heat-transfer plate stack and a cover, wherein a cover hole is defined in the cover.

According to some embodiments, the plate heat exchanger may receive gas from the outside through the cover hole defined in the cover. The heat-transfer plate stack may include first and second heat-transfer plates that are stacked with each other. A dead zone hole may extend through a dead zone formed in each of the first and second heat-transfer plates.

According to some embodiments, the heat-transfer plate stack may include a plurality of heat-transfer plates stacked with each other, wherein the plurality of heat-transfer plates have respective heat-transfer areas in and along which first fluid and second fluid having a lower temperature than a temperature of the first fluid flow such that the first and second fluids exchange heat with each other.

The cover may seal the heat-transfer plate stack from the outside out of the plate heat exchanger. The cover may have a thickness greater than that of each of the heat-transfer plates and may be made of a material having a strength greater than that of each of the heat-transfer plates. The cover may have a plate shape corresponding to a shape of each of the heat-transfer plates.

According to some embodiments, the heat-transfer plate stack may include at least one first heat-transfer plate and at least one second heat-transfer plate.

According to some embodiments, the at least one first heat-transfer plate may have a first heat-transfer area in which a first fluid channel in which the first fluid flows is formed.

According to some embodiments, the at least one second heat-transfer plate may have a second heat-transfer area in which a second fluid channel in which the second fluid flows is formed. The at least one second heat-transfer plate and the at least one first heat-transfer plate may be alternately stacked with each other and may be joined to each other.

According to some embodiments, each of the first and second heat-transfer plates may have a dead zone positioned in each of both opposing ends in a longitudinal direction of each of the first and second heat-transfer plates and outside each of the first and second heat-transfer areas. Each of the first and second fluids may be prevented from flowing into the dead zone.

According to some embodiments, the cover may have a cover hole defined therein through which gas is injected from the outside into the dead zone.

According to some embodiments, the dead zone may have at least one dead zone hole defined therein communicating with the cover hole. The inspection gas injected into the cover hole may be introduced into the dead zone to inspect the fluid-tightness of the dead zone.

According to some embodiments, the cover may include a plurality of covers respectively covering and sealing both opposing surfaces of the heat-transfer plate stack.

According to some embodiments, one of the plurality of covers may be coupled to one surface of the heat-transfer plate stack and may be configured to allow each of the first and second fluids to flow into the heat-transfer plate stack from an outside out of the plate heat exchanger therethrough and to flow out of the heat-transfer plate stack into the outside therethrough.

According to some embodiments, another of the plurality of covers may be coupled to the other surface opposite to one surface of the heat-transfer plate stack and may have a cover hole defined therein, and may seal the heat-transfer plate stack from the outside except for the cover hole.

According to some embodiments, the cover hole and the dead zone holes may overlap each other in a stacking direction of the heat-transfer plates and the covers, and communicate with each other. Accordingly, the gas injected through the cover hole may be quickly introduced into the dead zone through the dead zone hole, thereby reducing the inspection time.

According to some embodiments, the cover hole and the dead zone hole may have a circular shape with the same diameter.

According to some embodiments, the centers of the cover hole and the dead zone hole may coincide with each other. That is, the cover hole and the dead zone hole may be concentric with each other. Accordingly, the gas injected through the cover hole may be quickly introduced into the dead zone through the dead zone hole.

According to some embodiments, each of the first and second heat-transfer plates may be made of a first material. The cover may be made of a second material. The second material may have a greater strength than that of the first material. Accordingly, the formation of the hole for injecting gas is advantageous, and the cover hole is formed in the second cover having a strength greater than that of each of the first and second heat-transfer plates, such that the risk of the fluid flowing in the stack being exposed to the outside may be reduced.

According to some embodiments, each of the first and second heat-transfer plates may have a first thickness. The cover may have a second thickness. The second thickness may be larger than the first thickness.

According to some embodiments, in the fluid-tightness inspection of the dead zone, when the inspection gas is injected into the cover hole defined in the cover, the injected gas may flow into the dead zone through the dead zone hole formed in each of the dead zones of the first and second heat-transfer plates. Whether the gas introduced into the dead zone flows between the dead zone and the fluid channel (i.e., the first fluid channel) in which the water flows may be determined. Thus, the fluid-tightness of the dead zone may be identified based on the determination result. Further, based on the fluid-tightness inspection result of the dead zone, whether the brazing joining between the portions around the dead zones is defective may be determined.

According to some embodiments, in order to prevent external moisture from invading into the cover hole, the plate heat exchanger may further include the sealing to block and seal the cover hole after the fluid-tightness inspection of the dead zone has been completed.

According to various embodiments, the cover hole is formed in the cover sealing one surface of the heat-transfer plate, and gas may be injected into the cover hole from the outside. Furthermore, the dead zone hole communicating with the cover hole may be formed in the dead zone formed in the non-fluid channel area of the heat-transfer plate sealed with the cover. After brazing joining between the portions around the dead zones, the inspection gas (e.g., air, helium, etc.) may be first injected from the outside into the cover hole, and then, the injected gas may pass through the dead zone hole and flow into the inside of the dead zone. Thereafter, whether the gas flows between the dead zone and the fluid channel through which the first fluid (i.e., water) flows may be determined to inspect the fluid-tightness of the dead zone. Based on the inspection result, whether the brazing joining between the portions of the plates around the dead zone is defective may be easily and quickly inspected before the product shipment.

Furthermore, according to various embodiments, after the fluid-tightness inspection of the dead zone has been completed, the cover hole defined in the cover sealing the outside of the heat-transfer plate may be sealed and blocked. Accordingly, after the fluid-tightness inspection of the dead zone has been completed, moisture contained in the outside air may be prevented from flowing into the heat-transfer plate or the inside of the dead zone. As a result, unlike the conventional technology where the outside air can flow into the dead zone even after the fluid-tightness inspection has been completed, the infiltration of the outside moisture may be prevented in advance, thereby preventing freezing and breakage problems due to the moisture infiltration. In particular, the cover hole may be formed in the cover which has the strength and thickness greater than those of the heat-transfer plate. For this reason, there is an advantage in that various sealing schemes (e.g., plug, silicone, welding, etc.) may be used to seal the cover hole defined in the cover which has the good strength and larger thickness.

Furthermore, according to various embodiments, a hole into which the outside gas is injected is not defined in the heat-transfer plate having a small thickness and a weak strength but the cover hole which the outside gas is injected is defined in the cover thicker and stronger than the heat-transfer plate, thereby providing excellent workability of the hole into which the gas is injected, and various sealing means are available, and the problem of fluid being exposed to the outside due to corrosion of the heat-transfer plate may be prevented. Further, the shape and the number of holes may be changed in various ways.

In addition to the above-described effects, the specific effects of the present disclosure are described together with the specific details for carrying out the disclosure as set forth below.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view briefly illustrating a plate heat exchanger according to some embodiments.

FIG. 2 is a diagram briefly illustrating a first heat-transfer plate of a plate heat exchanger according to some embodiments.

FIG. 3 and FIG. 4 are diagrams showing an example of a position of a dead zone hole defined in a dead zone of a first heat-transfer plate of a plate heat exchanger according to some embodiments.

FIG. 5 is a diagram briefly illustrating a second heat-transfer plate of a plate heat exchanger according to some embodiments.

FIG. 6 and FIG. 7 are diagrams showing an example of a position of a dead zone hole defined in a dead zone of the second heat-transfer plate of the plate heat exchanger according to some embodiments.

FIG. 8 is an exploded perspective view in a stacking direction of a second cover, a second heat-transfer plate, and a first heat-transfer plate of a plate heat exchanger according to some embodiments.

FIG. 9 is a diagram showing a second cover of a plate heat exchanger according to some embodiments.

FIG. 10 and FIG. 11 are diagrams showing a location of a cover hole defined in a second cover of a plate heat exchanger according to some embodiments.

FIG. 12 and FIG. 13 are diagrams showing an operation of injecting inspection gas through the cover hole of the second cover according to some embodiments.

FIG. 14 and FIG. 15 are diagrams showing a structure in which after the fluid-tightness inspection of the dead zone, the cover hole is sealed with a sealing to prevent the intrusion of external moisture into the cover hole, according to some embodiments of the present disclosure.

DETAILED DESCRIPTIONS

The above-mentioned purpose, features, and advantages are described in detail below with reference to the attached drawings, and accordingly, a person having ordinary knowledge in the technical field to which the present disclosure belongs may easily carry out the technical idea of the present disclosure. In describing the present disclosure, when it is determined that a specific description of the publicly known technology related to the present disclosure may unnecessarily obscure the gist of the present disclosure, the detailed description thereof is omitted. Hereinafter, a preferred embodiment according to the present disclosure will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate identical or similar components.

As used herein, the singular constitutes “a” and “an” are intended to include the plural constitutes as well, unless the context clearly indicates otherwise.

In addition, it will also be understood that when a first element or layer is referred to as being present “on (or under)” a second element or layer, the first element may be disposed directly on (or under) the second element or may be disposed indirectly on (or under) the second element with a third element or layer being disposed between the first and second elements or layers.

It will be understood that when a first element or layer is referred to as being “connected to”, or “coupled to” a second element or layer, the first element may be directly connected to or coupled to the second element or layer, or one or more intervening elements or layers may be present therebetween.

Hereinafter, the plate heat exchanger according to various embodiments will be described in detail with reference to the attached drawings.

Overall Structure of Plate Heat Exchanger

The overall structure of the plate heat exchanger will be described.

FIG. 1 illustrates a plate heat exchanger according to some embodiments, FIGS. 2 to 4 briefly illustrate a first heat-transfer plate according to some embodiments, and FIGS. 5 to 7 briefly illustrate a second heat-transfer plate according to some embodiments.

A plate heat exchanger 1 according to some embodiments may include a heat-transfer plate stack 10 in which the first heat-transfer plates 20 and the second heat-transfer plates 30 are alternately stacked with each other and joined to each other, and a cover, i.e., a first cover 40 and a second cover 60.

Referring to FIG. 1, the first heat-transfer plates 20 and the second heat-transfer plates 30 constituting the heat-transfer plate stack 10 are alternately stacked with each other and joined to each other. In this regard, a stacking direction may be a front-back direction (FR direction, (see FIG. 1)). Furthermore, a longitudinal direction of each of the first heat-transfer plate 20 and the second heat-transfer plate 30 may be an up-down or vertical direction (UD direction, (see FIG. 1)). Furthermore, a width direction of each of the first heat-transfer plate 20 and the second heat-transfer plate 30 may be a left-right direction (LeRi direction, (see FIG. 1)).

However, referring to FIG. 1, it is illustrated that a length of the plate heat exchanger 1 is larger than a width thereof. However, the present disclosure is not limited thereto.

Therefore, although not shown separately, the length of the plate heat exchanger 1 may be equal to the width thereof, or the length of the plate heat exchanger 1 may be smaller than the width thereof. That is, various embodiments may be provided.

Referring to FIG. 1, the heat-transfer plate stack 10 is shown to include one first heat-transfer plate 20 and two second heat-transfer plates 30 respectively disposed on front and rear surfaces of the first heat-transfer plate 20. However, the present disclosure is not limited thereto.

Therefore, although not shown separately, the heat-transfer plate stack 10 may have various embodiments in which various numbers of the first heat-transfer plates 20 and various numbers of the second heat-transfer plates 30 are alternately stacked with each other and joined to each other.

Referring to FIG. 1 to FIG. 7, the plate heat exchanger 1 according to some embodiments includes the heat-transfer plate stack 10, the first cover 40, and the second cover 60.

The heat-transfer plate stack 10 may include a plurality of heat-transfer plates 20 and 30.

According to some embodiments, the heat-transfer plate stack 10 may include the plurality of heat-transfer plates 20 and 30.

The heat-transfer plate stack 10 may have a structure in which the plurality of heat-transfer plates 20 and 30 are alternately stacked with each other and joined to each other.

The plurality of heat-transfer plates 20 and 30 are alternately stacked with each other to allow relatively high temperature first fluid (e.g., water, etc.) W and relatively low temperature second fluid (e.g., refrigerant, etc.) R to flow through respective heat-transfer areas thereof to exchange heat with each other.

According to some preferred embodiments, the heat-transfer plate stack 10 may include the first heat-transfer plate 20.

The first heat-transfer plate 20 may have a first heat-transfer area 21 in which a first fluid channel in which the first fluid (e.g., water, etc.) W flows is formed.

According to some preferred embodiments, the heat-transfer plate stack 10 may further include the second heat-transfer plate 30.

The second heat-transfer plates 30 are alternately stacked with the first heat-transfer plates 20 to constitute the heat-transfer plate stack 10. The second heat-transfer plate 30 may have a second heat-transfer area 31 in which a second fluid channel in which the second fluid (e.g., refrigerant, etc.) R flows is formed.

According to some embodiments, the first heat-transfer plate 20 may have a dead zone 22 (“first dead zone”) formed in a non-fluid channel area (i.e., an area where fluid does not flow) outside the first heat-transfer area 21. In this regard, the dead zone 22 is an area also referred to as a cavity, where there is no fluid flow and where no fluid exists.

The dead zone 22 of the first heat-transfer plate 20 is structurally blocked from and thus does not fluid-communicate with the area where the first fluid W flows. Thus, the inflow of the first fluid W into the dead zone 22 does not occur.

According to some embodiments, the second heat-transfer plate 30 may have a dead zone 32 (“second dead zone”) formed in a non-fluid channel area (i.e., an area where fluid does not flow) outside the second heat-transfer area 31. In this regard, the dead zone 32 is an area also called a cavity, in which there is no fluid flow and no fluid exists.

The dead zone 32 of the second heat-transfer plate 30 is structurally blocked from and thus does not fluid-communicate with the area where the second fluid R flows. Thus, the inflow of the second fluid R to the dead zone 32 does not occur.

The first cover 40 may be coupled to one surface of the heat-transfer plate stack 10.

According to some embodiments, the first cover 40 may be coupled to a front surface among front and rear surfaces (both opposing surfaces in the front-rear direction of FIG. 1) of the heat-transfer plate stack 10 in which the plurality of first and second heat-transfer plates 20 and 30 are stacked (see FIG. 1).

The first cover 40 may introduce the first fluid (e.g., water, etc.) W from the outside into the heat-transfer plate stack 10 therethrough, or may discharge the first fluid (e.g., water, etc.) W that has completed the heat exchange with the second fluid from the heat-transfer plate stack 10 to the outside therethrough.

In this regard, the first fluid (e.g., water, etc.) W introduced into the heat-transfer plate stack 10 from the outside through the first cover 40 flows through respective first fluid inlets 201 and 301 of the first and second heat-transfer plates 20 and 30.

The introduced first fluid (e.g., water, etc.) W flows along the first heat-transfer area 21 of the first heat-transfer plate 20, and exchanges heat with the second fluid (e.g., refrigerant, etc.) R that flows along the second heat-transfer area 31 facing the first heat-transfer area 21.

Furthermore, the first cover 40 may introduce the second fluid (e.g., refrigerant, etc.) R into the heat-transfer plate stack 10 from the outside therethrough, or may discharge the second fluid (e.g., refrigerant, etc.) R subjected to the heat exchange with the first fluid to the outside out of the stack therethrough.

In this regard, the second fluid (e.g., refrigerant, etc.) R introduced into the heat-transfer plate stack 10 from the outside through the first cover 40 flows through respective second fluid inlets 203 and 303 of the first and second heat-transfer plates 20 and 30.

The introduced second fluid (e.g., refrigerant, etc.) R flows along the second heat-transfer area 31 of the second heat-transfer plate 30, and exchanges heat with the first fluid (e.g., water, etc.) W flowing along the first heat-transfer area 21 facing each other.

In this way, the first cover 40 may allow the first fluid (e.g., water, etc.) W to be introduced from the outside into the first and second heat-transfer plates 20 and 30 therethrough, or may allow the first fluid (e.g., water, etc.) W subjected to the heat exchange to be discharged from the first and second heat-transfer plates 20 and 30 to the outside therethrough.

Furthermore, the first cover 40 may allow the second fluid (e.g., refrigerant, etc.) R to be introduced from the outside into the first and second heat-transfer plates 20 and 30 therethrough or may allow the second fluid (e.g., refrigerant, etc.) R subjected to heat exchange to be discharged from the first and second heat-transfer plates 20 and 30 to the outside therethrough.

The second cover 60 may be coupled to the other surface of the heat-transfer plate stack 10.

According to some embodiments, the second cover 60 may be coupled to a rear surface among the front and rear surfaces (both opposing surfaces in the front-rear direction of FIG. 1) of the heat-transfer plate stack 10 in which the plurality of first and second heat-transfer plates 20 and 30 are stacked (see FIG. 1).

The second cover 60 may be coupled to the other surface of the heat-transfer plate stack 10 and may seal the other surface of the coupled heat-transfer plate stack 10 from the outside. That is, the second cover 60 may prevent exposure of the heat-transfer plate stack 10 to the outside and prevent the inflow of outside air into the heat-transfer plate stack 10.

In addition, the second cover 60 may have a cover hole 63 defined therein that allows gas to be injected into the heat-transfer plate stack 10 from the outside therethrough.

According to some embodiments, the cover hole 63 may be formed so as to extend through the second cover 60 in a thickness direction of the second cover 60. The cover hole 63 may receive gas for dead zone fluid-tightness inspection from the outside.

According to some embodiments, the cover hole 63 may be defined in the second cover 60 and, at the same time, dead zone holes 23 and 33 may be respectively defined in the respective dead zones 22 and 32 of the first and second heat-transfer plates 20 and 30. The dead zone holes 23 and 33 may communicate with the cover hole 63.

When the first and second heat-transfer plates 20 and 30 are alternately stacked with each other and joined to each other, portions around the respective dead zones 23 and 33 of the first and second heat-transfer plates 20 and 30 are fixed to each other via brazing joining.

After the brazing joining, fluid-tightness of the dead zone may be inspected. For this purpose, inspection gas may be injected from the outside through the cover hole 63.

The gas injected into the inside of the plate heat exchanger 1 through the cover hole 63 may be introduced into each of the dead zones through each of the dead zone holes 23 and 33 defined in each of the respective dead zones 22 and 32 of the first and second heat-transfer plates 20 and 30. Then, whether the introduced gas flows through the dead zone and toward the fluid channel through which the first fluid (e.g., water, etc.) W flows may be determined, and the fluid-tightness of the dead zone may be inspected based on the determination result. As a result, the brazing joining defect may be inspected in advance before shipment after the brazing joining of the plate heat exchanger. Thus, the product reliability may be improved.

In this regard, the inspection gas may be composed of air, helium, etc. However, the present disclosure is not necessarily limited to this composition of the gas and may have various other embodiments in terms of the composition of the gas.

Structure of Cover Hole and Dead Zone Hole

According to some embodiments, the cover hole 63 may overlap the dead zone holes 23 and 33 in the front-rear direction in FIG. 1.

Accordingly, when the inspection gas G has been injected into the inside of the plate heat exchanger 1 through the cover hole 63 defined in the second cover 60, the injected gas G may flow through each of the dead zone holes 23 and 33 and then quickly and smoothly flow into the inside of each of the dead zones 22 and 32. As a result, a time required for the fluid-tightness inspection of the dead zone may be shortened, and a sufficient amount of the gas may be introduced into the dead zone, so that the inspection of the fluid-tightness between the dead zone and the fluid channel through which the first fluid (e.g., water, etc.) flows may be accurately performed.

According to some embodiments, the cover hole 63 and the dead zone holes 23 and 33 may have a circular shape with the same diameter.

According to some preferred embodiments, respective hole centers of the cover hole 63 and the dead zone holes 23 and 33 may coincide with each other, that is, overlap each other in the front-rear direction in FIG. 1. In other words, the cover hole 63 and the dead zone holes 23 and 33 may be concentric with each other so that the cover hole 63 and the dead zone holes 23 and 33 may overlap with each other in the stacking direction of the plates and communicate with each other.

Accordingly, the gas injected through the cover hole 63 may be quickly introduced into the inside of each of the dead zones 22 and 32 through each of the dead zone holes 23 and 33. A sufficient amount of the gas may be introduced into the dead zones 22 and 32. Thus, the fluid-tightness inspection of the dead zone may be performed more accurately.

Alternatively, according to some further embodiments, the hole centers of the cover hole 63 and the dead zone holes 23 and 33 may coincide with each other, while the diameter of the cover hole 63 may be larger than the diameter of each of the dead zone holes 23 and 33.

According to this configuration, there is an advantage in that the inspection gas may be injected more quickly into the heat-transfer plate stack 10 from the outside through the cover hole 63 having a relatively large diameter. In this regard, the second cover 60 may have a thickness larger than that of each of the first and second heat-transfer plates 20 and 30. For this reason, the cover hole 63 having the large diameter may be formed in the second cover 60 having a relatively large thickness, so that the structural strength thereof may be prevented from being deteriorated. In other words, because the second cover 60 has a strength greater than that of each of the first and second heat-transfer plates 20 and 30, the diameter of the cover hole 63 may be larger than the diameter of each of the dead zone holes 23 and 33.

According to some embodiments, the cover hole 63 may include a plurality of cover holes positioned at different positions of the second cover 60.

According to some preferred embodiments, the cover hole 63 may be formed in each of one end (i.e., upper end) located in the upward direction U (see FIG. 1) of the second cover 60 and the other end (i.e., lower end) located in the downward direction D (see FIG. 1) of the second cover 60.

Each of the dead zone holes 23 and 33 defined in each of the first and second heat-transfer plates 20 and 30 may include a plurality of dead zones, the number thereof corresponding to the number of the cover holes 63.

According to some preferred embodiments, each of the dead zone holes 23 and 33 may include both dead zone holes respectively defined at both opposing ends in the upward-downward direction of each of the first and second heat-transfer plates 20 and 30 and respectively corresponding to the both cover holes 63 respectively defined at both opposing ends in the upward-downward direction of the second cover 60. Furthermore, corresponding one of the plurality of cover holes 63, corresponding one of the plurality of dead zone holes 23, and corresponding one of the plurality of dead zone holes 33 may be concentric with each other and overlap each other in the front-rear direction and communicate with each other.

Material and Thickness of Each of Cover and Heat-Transfer Plate

According to some embodiments, each of the first and second heat-transfer plates 20 and 30 may be made of a first material. Each of the first and second covers 40 and 60 may be made of a second material. In this case, the second material may have a strength greater than that of the first material.

In this way, the second material constituting the second cover 60 having the cover hole 63 defined therein into which the inspection gas is injected from the outside may have the strength greater than that of the first material constituting each of the first and second heat-transfer plates 20 and 30.

Furthermore, each of the first and second heat-transfer plates may have a first thickness. The second cover may have a second thickness. In this regard, the second thickness may be larger than the first thickness. That is, the second cover may have a larger thickness than that of each of the first and second heat-transfer plates.

Accordingly, good hole workability of the cover hole 63 may be achieved.

Since the cover hole 63 is formed in the second cover 60 that seals the first and second heat-transfer plates 20 and 30, the fluid flowing through the first and second heat-transfer plates 20 and 30 may be prevented from leaking out of the second cover 60.

According to some preferred embodiments, the first heat-transfer plate 20 may be made of a SUS316L material. Furthermore, the second heat-transfer plate 30 may be made of a SUS316L material.

Each of the first and second covers 40 and 60 may be made of a SUS304 material.

In this regard, SUS304 as the material of the second cover 60 has a relatively higher content of each of chromium and nickel than that in SUS316L as the material of each of the first and second heat-transfer plates 20 and 30, and thus has excellent heat resistance, wear resistance, and weldability.

SUS316L as the material of each of the first and second heat-transfer plates 20 and 30 has a higher molybdenum content than that in SUS304 as the material of the second cover 60, and thus has enhanced corrosion resistance, thus making it suitable for use in environments with a high possibility of corrosion. Therefore, SUS316L may act as the material of each of the heat-transfer plates through which each of the first and second fluids flows.

In addition, SUS304 as the material of the second cover 60 has excellent heat resistance, wear resistance, and weldability, and advantageously seals the cover hole 63 in various schemes after the fluid-tightness inspection of the dead zone. For example, when the second cover 60 is made of SUS304 material, the cover hole may be blocked using a mechanical sealing means such as a plug, or by injecting silicone, etc. into the cover hole to seal the cover hole, or via welding.

According to some preferred embodiments, the second cover 60 may have a thickness that is greater by 5 to 7 times than that of each of the first and second heat-transfer plates 20 and 30.

For example, when the thickness of each of the first and second heat-transfer plates 20 and 30 is in a range of 0.2 mm to 0.4 mm, the thickness of the second cover 60 may be in a range of 1.0 mm to 2.8 mm.

In this way, when the second cover 60 has the thickness that is larger by 5 to 7 times than that of each of the first and second heat-transfer plates 20 and 30, there is an advantage in that the cover hole having a hole shape and a hole size that are advantageous for gas injection may be formed easily.

Furthermore, when the cover hole 63 is blocked with various sealing means after the fluid-tightness inspection of the dead zone, a stronger sealing force may be secured because the thickness of the second cover 60 in which the cover hole 63 is formed is sufficiently large.

Structure of First Cover

According to some embodiments, the first cover 40 may have a first fluid outside-communicating inlet 401 defined therein (see FIG. 1).

The first fluid outside-communicating inlet 401 refers to an inlet through which the first fluid (e.g., water, etc.) W flows into the heat-transfer plate stack 10 from the outside out of the first cover 40. The first fluid (e.g., water, etc.) W may be introduced into the heat-transfer plate stack 10, (i.e., the first and second heat-transfer plates 20 and 30) through the first fluid outside-communicating inlet 401.

According to some embodiments, the first cover 40 may have a first fluid outside-communicating outlet 402 defined therein (see FIG. 1).

The first fluid outside-communicating outlet 402 refers to an outlet through which the first fluid (e.g., water, etc.) W flowing out of the first and second heat-transfer plates 20 and 30 is discharged to the outside out of the first cover 40. While the first fluid (e.g., water, etc.) W flows along a set first fluid channel while flowing through the first and second heat-transfer plates 20 and 30 stacked with each other, the heat exchange between the first and second fluids occurs. Then, after the heat exchange, the first fluid may flow out to the outside out of the first cover 40.

According to some embodiments, the first cover 40 may have a second fluid outside-communicating inlet 403 defined therein (see FIG. 1).

The second fluid outside-communicating inlet 403 refers to an inlet through which the second fluid (e.g., refrigerant, etc.) R flows into the heat-transfer plate stack 10 from the outside out of the first cover 40. The second fluid (e.g., refrigerant, etc.) R may flow into the heat-transfer plate stack 10, (i.e., the first and second heat-transfer plates 20 and 30) through the second fluid outside-communicating inlet 403.

According to some embodiments, the first cover 40 may have a second fluid outside-communicating outlet 404 defined therein (see FIG. 1).

The second fluid outside-communicating outlet 404 refers to an outlet through which the second fluid (e.g., refrigerant, etc.) R flowing out of the first and second heat-transfer plates 20 and 30 is discharged to the outside out of the first cover 40. While the second fluid (e.g., refrigerant, etc.) R flows along a set second fluid channel while flowing through the first and second heat-transfer plates 20 and 30 stacked with each other, the heat exchange between the first and second fluids occurs. Then, after the heat exchange, the second fluid may be discharged to the outside out of the first cover 40.

In this way, the first cover 40 may have the first fluid outside-communicating inlet 401 and the first fluid outside-communicating outlet 402 defined therein for introducing the first fluid (e.g., water, etc.) W into the heat-transfer plate stack 10 from the outside, or for discharging the first fluid (e.g., water, etc.) W subjected to the heat exchange to the outside out of the heat-transfer plate stack 10.

Furthermore, the first cover 40 may have the second fluid outside-communicating inlet 403 and the second fluid outside-communicating outlet 404 defined therein for introducing the second fluid (e.g., refrigerant, etc.) R into the heat-transfer plate stack 10 from the outside, or for discharging the second fluid (e.g., refrigerant, etc.) R subjected to the heat exchange to the outside out of the heat-transfer plate stack 10.

The first cover 40 may be formed to seal the first and second heat-transfer plates 20 and 30 from the outside except for the first fluid outside-communicating inlet 401 and the first fluid outside-communicating outlet 402, and the second fluid outside-communicating inlet 403 and the second fluid outside-communicating outlet 404.

Structure of First Heat-Transfer Plate

FIGS. 2 to 4 are schematic illustrations of the first heat-transfer plate according to some embodiments.

According to some embodiments, the first heat-transfer plate 20 may have the first heat-transfer area 21. The first fluid channel in which the first fluid (e.g., water, etc.) W flows may be formed in the first heat-transfer area 21.

The heat-transfer plate stack 10 includes a stack of the first heat-transfer plate 20 having the first heat-transfer area 21 in which the high-temperature first fluid (e.g., water, etc.) W flows, and the second heat-transfer plate 20 having the second heat-transfer area 31 in which the low-temperature second fluid (e.g., refrigerant, etc.) R flows.

The first heat-transfer plates 20 and the second heat-transfer plates 30 are alternately stacked with each other, so that the first fluid (e.g., water, etc.) W flowing through the first heat-transfer area 21 exchanges heat with the second fluid (e.g., refrigerant, etc.) R flowing through the second heat-transfer area 31.

According to some embodiments, the first heat-transfer plate 20 may have a first heat-transfer plate first fluid inlet 201 defined therein.

The first heat-transfer plate first fluid inlet 201 may be located at one end (e.g., lower end) (see FIG. 2) in the longitudinal direction (UD direction) of the first heat-transfer plate 20. The first heat-transfer plate first fluid inlet 201 may act as an inlet through which the first fluid (e.g., water, etc.) W flows into the heat-transfer plate stack 10.

The first heat-transfer plate first fluid inlet 201 may be connected to the fluid channel (i.e., the first fluid channel) through which the first fluid flows in the first heat-transfer area 21. Accordingly, the first fluid (e.g., water, etc.) W introduced into the first heat-transfer plate first fluid inlet 201 may flow along the first heat-transfer area 21.

According to some embodiments, the first heat-transfer plate 20 may have a first heat-transfer plate first fluid outlet 202 defined therein.

The first heat-transfer plate first fluid outlet 202 may be located at the other end (e.g., upper end) (see FIG. 2) in the longitudinal direction (UD direction) of the first heat-transfer plate 20. The first heat-transfer plate first fluid outlet 202 may act as an outlet through which the first fluid (e.g., water, etc.) W flows out of the heat-transfer plate stack 10.

The first heat-transfer plate first fluid outlet 202 may be connected to the fluid channel (i.e., the first fluid channel) through which the first fluid flows in the first heat-transfer area 21. Accordingly, the first fluid (e.g., water, etc.) W flowing along the first heat-transfer area 21 may flow out of the heat-transfer plate stack 10 through the first heat-transfer plate first fluid outlet 202.

According to some embodiments, the first heat-transfer plate 20 may have a first heat-transfer plate second fluid inlet 203 defined therein.

The first heat-transfer plate second fluid inlet 203 may be located at the other end (e.g., upper end) (see FIG. 2) in the longitudinal direction (UD direction) of the first heat-transfer plate 20. The first heat-transfer plate second fluid inlet 203 may act as an inlet for introducing the second fluid (e.g., refrigerant, etc.) R into the heat-transfer plate stack 10.

According to some preferred embodiments, the first heat-transfer plate second fluid inlet 203 may be disposed on one side (e.g., the right side) of the first heat-transfer plate first fluid outlet 202 (see FIG. 2) and be spaced apart therefrom.

The first heat-transfer plate second fluid inlet 203 may be blocked from the first heat-transfer area 21 and thus may not communicate therewith. That is, the first heat-transfer plate second fluid inlet 203 may be blocked from the fluid channel (i.e., the first fluid channel) through which the first fluid flows and thus may not communicate therewith. Accordingly, the second fluid (e.g., refrigerant, etc.) R may be prevented from flowing toward the first heat-transfer area 21.

According to some embodiments, the first heat-transfer plate 20 may further have a first heat-transfer plate second fluid outlet 204 defined therein.

The first heat-transfer plate second fluid outlet 204 may be located at one end (e.g., lower end) (see FIG. 2) of the longitudinal direction (UD direction) of the first heat-transfer plate 20. The first heat-transfer plate second fluid outlet 204 may act as an outlet through which the second fluid (e.g., refrigerant, etc.) R flows out of the heat-transfer plate stack 10.

According to some preferred embodiments, the first heat-transfer plate second fluid outlet 204 may be positioned on one side (e.g., right side) (see FIG. 2) of the first heat-transfer plate first fluid inlet 201 and be spaced from the first heat-transfer plate first fluid inlet 201.

The first heat-transfer plate second fluid outlet 204 may be blocked from the first heat-transfer area 21, and thus may not communicate therewith. That is, the first heat-transfer plate second fluid outlet 204 may be blocked from the fluid channel (i.e., the first fluid channel) through which the first fluid flows and thus may not communicate therewith. Accordingly, the second fluid (e.g., refrigerant, etc.) R may be prevented from flowing toward the first heat-transfer area 21.

Hereinafter, the structure of the first heat-transfer plate 20 according to some preferred embodiments will be described in more detail with reference to FIGS. 2 to 4.

The first heat-transfer plate 20 may have the first heat-transfer area 21 through which the first fluid (e.g., water, etc.) W flows.

The first heat-transfer plate 20 may have the first heat-transfer plate first fluid inlet 201 defined therein through which the first fluid (e.g., water, etc.) W introduced through the first fluid outside-communicating inlet 401 (see FIG. 1) of the first cover 40 flows into the heat-transfer plate stack 10.

The first heat-transfer plate first fluid inlet 201 may be located in a lower left area S1 around the first heat-transfer area 21.

The first heat-transfer plate 20 may have the first heat-transfer plate first fluid outlet 202 defined therein through which the first fluid (e.g., water, etc.) W is discharged out of the heat-transfer plate stack 10.

The first heat-transfer plate first fluid outlet 202 may be located in an upper left area S1 around the first heat-transfer area 21. The first fluid (e.g., water, etc.) W flowing out of the first heat-transfer plate first fluid outlet 202 may flow to the outside out of the plate heat exchanger through the first fluid outside-communicating outlet 402 of the first cover 40.

The first heat-transfer plate 20 may have the first heat-transfer plate second fluid inlet 203 defined therein through which the second fluid (e.g., refrigerant, etc.) R introduced through the second fluid outside-communicating inlet 403 (see FIG. 1) of the first cover 40 flows into the heat-transfer plate stack 10.

The first heat-transfer plate second fluid inlet 203 may be located in an upper right area S2 around the first heat-transfer area 21.

The first heat-transfer plate 20 may have the first heat-transfer plate second fluid outlet 204 defined therein through which the second fluid (e.g., refrigerant, etc.) R flows out of the heat-transfer plate stack 10.

The first heat-transfer plate second fluid outlet 204 may be located in a lower right area S2 around the first heat-transfer area 21. The second fluid (e.g., refrigerant, etc.) R flowing out of the first heat-transfer plate second fluid outlet 204 may flow to the outside out of the plate heat exchanger through the second fluid outside-communicating outlet 404 of the first cover 40.

According to some embodiments, the first heat-transfer area 21 may include a ridge 211 and a valley 212.

The valley 212 may be located between adjacent ones of a plurality of ridges 211. Furthermore, the valley 212 may have a stepped shape with respect to the ridge 211.

According to some embodiments, the first heat-transfer area 21 may have a wave shape in which the ridges 211 and the valleys 212 are alternately arranged with each other.

According to some preferred embodiments, the wave shape of the first heat-transfer area 21 may be an inverted-V shape or a V shape. Accordingly, a heat transfer area of the first fluid (e.g., water, etc.) W flowing along the first heat-transfer area 21 may be increased, thereby improving performance and efficiency.

Each of the ridges 211 and the valleys 212 in the first heat-transfer area 21 may extend in the left-right direction (LeRi direction).

Each of the ridges 211 and the valleys 212 of the first heat-transfer area 21 may have an inverted V shape or V shape in which an extension direction changes at a boundary between the left area S1 and the right area S2.

According to some preferred embodiments, each of the ridges 211 and the valleys 212 of the first heat-transfer area 21 may extend in an inclined manner upwardly from a left end LE of the first heat-transfer plate 20 to the boundary between the left area S1 and the right area S2. Furthermore, each of the ridges 211 and the valleys 212 of the first heat-transfer area 21 may extend in an inclined manner downwardly from the boundary between the left area S1 and the right area S2 toward a right end RE of the first heat-transfer plate 20 (see FIG. 2 to FIG. 4).

According to some embodiments, the first heat-transfer plate 20 may include a flat portion 25.

The flat portion 25 refers to a portion that surrounds the first heat-transfer plate first fluid inlet 201 and the first heat-transfer plate first fluid outlet 202 through which the first fluid (e.g., water, etc.) W flows and has a flat shape with a predetermined area.

An example where the first fluid (e.g., water, etc.) W is cooled by the second fluid (e.g., refrigerant, etc.) R will be described.

The first fluid (e.g., water, etc.) W flowing through the first fluid inlet 201 of the first heat-transfer plate may be frozen by the second fluid (e.g., refrigerant, etc.) R flowing through the second fluid outlet 204 of the first heat-transfer plate. Alternatively, the first fluid (e.g., water, etc.) W flowing through the first fluid outlet 302 of the second heat-transfer plate may be frozen by the second fluid (e.g., refrigerant, etc.) R flowing through the second fluid inlet 303 of the second heat-transfer plate.

When the flat portion 25 has an asymmetrical shape around a center of the first fluid inlet 201 of the first heat-transfer plate, the flow of the first fluid (e.g., water, etc.) W in the first fluid inlet 201 of the first heat-transfer plate may be prevented from stagnating, thereby preventing freezing thereof.

In other words, the asymmetrical flat portion 25 may prevent the flow of the first fluid (e.g., water, etc.) W in the first fluid inlet 201 of the first heat-transfer plate from slowing down or stagnating, thereby preventing freezing and breakage accident. In this manner, the asymmetrical flat portion 25 may also be formed around the first fluid outlet 202 of the first heat-transfer plate.

According to some preferred embodiments, the flat portion 25 may further be provided with a protrusion 26. The protrusion 26 may be positioned at and protrude from a set position of the flat portion 25 preventing the flow of the first fluid (e.g., water, etc.) W from stagnating. The protrusion 26 may prevent eddies and guide the flow direction of the first fluid (e.g., water, etc.) W. The protrusion 26 may have various shapes, such as a cylindrical or polygonal columnar shape.

According to some embodiments, the first heat-transfer plate 20 may have the dead zone 22 as a non-fluid channel area where fluid does not flow at a location outside the first heat-transfer area 21.

Referring to FIG. 3 and FIG. 4, the dead zone 22 of the first heat-transfer plate 20 may be located at the right area S2 of each of the upper and lower ends in the longitudinal direction of the first heat-transfer plate 20 outside the first heat-transfer area 21. The first fluid W does not flow into the dead zone 22 of the first heat-transfer plate 20.

The dead zone 22 of the first heat-transfer plate 20 may be formed at a corner position adjacent to each of the first heat-transfer plate second fluid inlet 203 and the first heat-transfer plate second fluid outlet 204 through which the second fluid (e.g., refrigerant, etc.) R flows.

According to some preferred embodiments, a first flange 27 may be further disposed along an edge of the first heat-transfer plate 20. Each corner of the first heat-transfer plate 20 may have a round shape.

The dead zone hole 23 of the first heat-transfer plate 20 may be formed so as to extend through the dead zone 32 provided at a corner adjacent to the second fluid inlet 203 of the first heat-transfer plate 20 in the thickness direction of the first heat-transfer plate 20 (see FIG. 3).

Furthermore, the dead zone hole 23 of the first heat-transfer plate 20 may be formed so as to extend through the dead zone 32 provided at a corner adjacent to the second fluid outlet 204 of the first heat-transfer plate 20 in the thickness direction of the first heat-transfer plate 20 (see FIG. 4).

According to some preferred embodiments, the dead zone hole 23 may be space apart from each of the second fluid inlet 203 of the first heat-transfer plate and the second fluid outlet 204 of the first heat-transfer plate by a set distance HL. Further, the dead zone hole 23 may be positioned close to the first flange 27 that surrounds the round-shaped corner of the first heat-transfer plate 20. Accordingly, even when the dead zone hole is formed in the thin second heat-transfer plate 30, the required rigidity of the second heat-transfer plate 30 may be maintained.

Structure of Second Heat-Transfer Plate

FIG. 5 to FIG. 7 are schematic illustrations of the second heat-transfer plate according to some embodiments.

According to some embodiments, the second heat-transfer plate 30 may have the second heat-transfer area 31. The second fluid channel in which the second fluid (e.g., refrigerant, etc.) R flows may be formed in the second heat-transfer area 31.

The heat-transfer plate stack 10 includes the first heat-transfer plate 20 having the first heat-transfer area 21 in which the high-temperature first fluid (e.g., water, etc.) W flows, and the second heat-transfer plate 30 having the second heat-transfer area 31 in which the low-temperature second fluid (e.g., refrigerant, etc.) R flows.

The second heat-transfer plates 30 and the above-described first heat-transfer plates 20 may be alternately stacked with each other. The second heat-transfer plate 30 allows the second fluid (e.g., refrigerant, etc.) R flowing through the second heat-transfer area 31 to heat-exchange with the first fluid (e.g., water, etc.) W flowing through the first heat-transfer area 21.

According to some embodiments, the second heat-transfer plate 30 may have a second heat-transfer plate second fluid inlet 303 defined therein.

The second heat-transfer plate second fluid inlet 303 may be located at the other end (e.g., upper end) (see FIG. 5) in the longitudinal direction (UD direction) of the second heat-transfer plate 30.

The second heat-transfer plate second fluid inlet 303 may act as an inlet through which the second fluid (e.g., refrigerant, etc.) R flows.

The second heat-transfer plate second fluid inlet 303 may be connected to the fluid channel (i.e., the second fluid channel) through which the second fluid flows in the second heat-transfer area 31. Accordingly, the second fluid (e.g., refrigerant, etc.) R introduced into the second heat-transfer plate second fluid inlet 303 may flow along the second heat-transfer area 31.

According to some embodiments, the second heat-transfer plate 30 may include a second heat-transfer plate second fluid outlet 304 defined therein.

The second heat-transfer plate second fluid outlet 304 may be located at one end (e.g., lower end) (see FIG. 5) in the longitudinal direction (UD direction) of the second heat-transfer plate 30. The second heat-transfer plate second fluid outlet 304 may act as an outlet through which the second fluid (e.g., refrigerant, etc.) R flows out of the heat-transfer plate stack 10.

The second heat-transfer plate second fluid outlet 304 may be connected to the fluid channel (i.e., the second fluid channel) through which the second fluid flows in the second heat-transfer area 31. Accordingly, the second fluid (e.g., refrigerant, etc.) R flowing along the second heat-transfer area 31 may flow out of the heat-transfer plate stack 10 through the second heat-transfer plate second fluid outlet 304.

According to some embodiments, the second heat-transfer plate 30 may further include a second heat-transfer plate first fluid inlet 301 defined therein.

The second heat-transfer plate first fluid inlet 301 may be located at one end (e.g., the lower end) (see FIG. 5) in the longitudinal direction (UD direction) of the second heat-transfer plate 30. The second heat-transfer plate first fluid inlet 301 may act as an inlet through which the first fluid (e.g., water, etc.) W flows into the heat-transfer plate stack 10.

According to some preferred embodiments, the second heat-transfer plate first fluid inlet 301 may be positioned on the other side (e.g., the left side) of the second heat-transfer plate second fluid outlet 304 and be spaced therefrom (see FIG. 5).

The second heat-transfer plate first fluid inlet 301 may be blocked from the second heat-transfer area 31, and thus may not communicate therewith. That is, the second heat-transfer plate first fluid inlet 301 may be blocked from the fluid channel (i.e., the second fluid channel) through which the second fluid flows and thus may not communicate therewith. Accordingly, the first fluid (e.g., water, etc.) W may be prevented from flowing toward the second heat-transfer area 31.

According to some embodiments, the second heat-transfer plate 30 may further have a second heat-transfer plate first fluid outlet 302 defined therein.

The second heat-transfer plate first fluid outlet 302 may be located at the other end (e.g., upper end) in the longitudinal direction (UD direction) of the second heat-transfer plate 30 (see FIG. 5).

The second heat-transfer plate first fluid outlet 302 may act as an outlet through which the first fluid (e.g., water, etc.) W flows out of the heat-transfer plate stack 10.

According to some preferred embodiments, the second heat-transfer plate first fluid outlet 302 may be located on the other side (e.g., left side) of the second heat-transfer plate second fluid inlet 303 and be spaced therefrom (see FIG. 5).

The first fluid outlet 302 of the second heat-transfer plate may be blocked from the second heat-transfer area 31, and thus may not communicate therewith. That is, the first fluid outlet 302 of the second heat-transfer plate may be blocked from the fluid channel (i.e., the second fluid channel) through which the second fluid flows and thus may not communicate therewith. Accordingly, the first fluid (e.g., water, etc.) W may be prevented from flowing toward the second heat-transfer area 31.

Hereinafter, the structure of the second heat-transfer plate 30 according to some preferred embodiments will be described in more detail with reference to FIGS. 5 to 7.

The second heat-transfer plate 30 may have the second heat-transfer area 31 through which the second fluid (e.g., refrigerant, etc.) R flows.

The second heat-transfer plate 30 may have the second heat-transfer plate second fluid inlet 303 through which the second fluid (e.g., refrigerant, etc.) R introduced through the second fluid outside-communicating inlet 403 (see FIG. 1) of the first cover 40 flows into the heat-transfer plate stack 10.

The second heat-transfer plate second fluid inlet 303 may be located in the upper right area S2 around the second heat-transfer area 31. The second heat-transfer plate 30 may have the second heat-transfer plate second fluid outlet 304 defined therein through which the second fluid (e.g., refrigerant, etc.) W flows out of the heat-transfer plate stack 10.

The second heat-transfer plate second fluid outlet 304 may be located in the lower right area S2 around the second heat-transfer area 31. The second fluid flowing out of the second heat-transfer plate second fluid outlet 304 may flow out to the outside out of the plate heat exchanger through the second fluid outside-communicating outlet 404 (see FIG. 1) of the first cover 40.

The second heat-transfer plate 30 may have the second heat-transfer plate first fluid inlet 301 defined therein through which the first fluid (e.g., water, etc.) W introduced through the first fluid outside-communicating inlet 401 (see FIG. 1) of the first cover 40 flows into the heat-transfer plate stack 10.

The second heat-transfer plate first fluid inlet 301 may be located in the lower left area S1 around the second heat-transfer area 31.

The second heat-transfer plate 30 may have the second heat-transfer plate first fluid outlet 302 defined therein through which the first fluid (e.g., water, etc.) W flows out of the heat-transfer plate stack 10.

The second heat-transfer plate first fluid outlet 302 may be located in the upper left area S2 around the second heat-transfer area 31. The first fluid flowing out of the second heat-transfer plate first fluid outlet 302 may flow out to the outside out of the plate heat exchanger through the first fluid outside-communicating outlet 402 of the first cover 40 (see FIG. 1).

According to some embodiments, the second heat-transfer area 31 may include ridges 311 and valleys 312.

The valley 312 may be located between adjacent ones of a plurality of ridges 311. Furthermore, the valley 312 may have a stepped shape with respect to the ridge 311.

According to some embodiments, the second heat-transfer area 31 may have a wave shape in which the ridges 311 and the valleys 312 are alternately arranged with each other.

According to some preferred embodiments, the wave shape of the second heat-transfer area 31 may be an inverted-V shape or a V shape. Accordingly, the heat transfer area of the second fluid (e.g., refrigerant, etc.) R flowing along the second heat-transfer area 31 may be increased, thereby improving performance and efficiency.

Each of the ridges 311 and the valleys 312 in the second heat-transfer area 31 may extend in the left-right direction (LeRi direction).

Each of the ridges 311 and the valleys 312 of the second heat-transfer area 31 may have an inverted V shape or V shape in which an extension direction changes at a boundary between the left area S1 and the right area S2.

According to some preferred embodiments, each of the ridges 311 and the valleys 312 of the second heat-transfer area 31 may extend in an inclined manner downwardly from the left end LE of the second heat-transfer plate 30 to the boundary between the left area S1 and the right area S2. Furthermore, each of the ridge 311 and the valley 312 of the second heat-transfer area 31 may extend in an inclined manner upwardly from the boundary between the left area S1 and the right area S2 toward the right end RE of the second heat-transfer plate 30 (see FIG. 5 to FIG. 7).

According to some embodiments, the second heat-transfer plate 30 may include a flat portion 35.

The flat portion 35 refers to a portion having a flat shape with a predetermined area, and surrounding each of the first fluid inlet 301 of the second heat-transfer plate and the first fluid outlet 302 of the second heat-transfer plate through which the first fluid (e.g., water, etc.) W flows.

An example where the first fluid (e.g., water, etc.) W is cooled by the second fluid (e.g., refrigerant, etc.) R will be described.

The first fluid (e.g., water, etc.) W flowing through the first fluid inlet 301 of the second heat-transfer plate may be frozen by the second fluid (e.g., refrigerant, etc.) R flowing through the second fluid outlet 304 of the second heat-transfer plate. Alternatively, the first fluid (e.g., water, etc.) W flowing through the first fluid outlet 302 of the second heat-transfer plate may be frozen by the second fluid (e.g., refrigerant, etc.) R flowing through the second fluid inlet 303 of the second heat-transfer plate.

When the flat portion 35 has an asymmetrical shape around the center of the first fluid inlet 301 of the second heat-transfer plate, the flow of the first fluid (e.g., water, etc.) W in the first fluid inlet 301 of the second heat-transfer plate may be prevented from stagnating, thereby preventing freezing thereof.

In other words, the asymmetrical flat portion 35 may prevent the flow of the first fluid (e.g., water, etc.) W in the first fluid inlet 301 of the second heat-transfer plate from slowing down or stagnating, thereby preventing freezing and breakage accident. In this manner, the asymmetrical flat portion 35 may also be formed around the first fluid outlet 302 of the second heat-transfer plate.

According to some preferred embodiments, the flat portion 35 may further be provided with a protrusion 36. The protrusion 36 may be positioned at and protrude from a set position of the flat portion 35 preventing the flow of the first fluid (e.g., water, etc.) W from stagnating. The protrusion 36 may prevent eddies and guide the flow direction of the first fluid (e.g., water, etc.) W. The protrusion 36 may have various shapes, such as a cylindrical or polygonal columnar shape.

According to some embodiments, the second heat-transfer plate 30 may have the dead zone 32 as a non-fluid channel area where fluid does not flow at a location outside the second heat-transfer area 31.

Referring to FIG. 6 and FIG. 7, the dead zone 32 of the second heat-transfer plate 30 may be located at the right area S2 of each of the upper and lower ends in the longitudinal direction of the second heat-transfer plate 30 outside the second heat-transfer area 31. The first fluid W does not flow into the dead zone 32 of the second heat-transfer plate 30.

The dead zone 32 of the second heat-transfer plate 30 may be formed at a corner position adjacent to each of the second heat-transfer plate second fluid inlet 303 and the second heat-transfer plate second fluid outlet 304 through which the second fluid (e.g., refrigerant, etc.) R flows.

According to some preferred embodiments, a second flange 37 may be further disposed along an edge of the second heat-transfer plate 30. Further, each corner of the second heat-transfer plate 30 may have a round shape.

The dead zone hole 33 of the second heat-transfer plate 30 may be formed so as to extend through the dead zone 32 provided at a corner adjacent to the second fluid inlet 303 of the second heat-transfer plate 30 in the thickness direction of the second heat-transfer plate 30 (see FIG. 6).

Furthermore, the dead zone hole 33 of the second heat-transfer plate 30 may be formed so as to extend through the dead zone 32 provided at a corner adjacent to the second fluid outlet 304 of the second heat-transfer plate 30 in the thickness direction of the second heat-transfer plate 30 (see FIG. 7).

According to some preferred embodiments, the dead zone hole 33 may be space apart from each of the second fluid inlet 303 of the second heat-transfer plate and the second fluid outlet 304 of the second heat-transfer plate by a set distance HL. Further, the dead zone hole 33 may be positioned close to the second flange 37 that surrounds the round-shaped corner of the second heat-transfer plate 30. Accordingly, even when the dead zone hole is formed in the thin second heat-transfer plate 30, the required rigidity of the second heat-transfer plate 30 may be maintained.

Stacking Structure of Second Cover, Second Heat-Transfer Plate, and First Heat-Transfer Plate

FIG. 8 is an exploded perspective view in a stacking direction of the first heat-transfer plate, the second heat-transfer plate, and the second cover in the plate heat exchanger according to some embodiments, and FIGS. 9 to 11 are diagrams that briefly illustrate the second cover and a position of the cover hole.

Referring to FIG. 8, the first heat-transfer plate 20, the second heat-transfer plate 30, and the second cover 60 may be stacked with each other and joined to each other to each other in the stacking direction.

According to some embodiments, the dead zone 22 of the first heat-transfer plate 20 and the dead zone 23 of the second heat-transfer plate may be stacked and combined with each other so as to overlap each other in the stacking direction.

The second cover 60 has a plurality of cover holes 63 defined therein (see FIG. 9 to FIG. 11).

A position of each of the plurality of cover holes 63 may correspond to and overlap in the stacking direction the position of each of the respective dead zone holes 23 and 33 of the first and second heat-transfer plates 20 and 30 (see FIG. 8).

Furthermore, in the first and second heat-transfer plates 20 and 30 stacked with each other and joined to each other to each other in the stacking direction such that the dead zones 22 and 32 overlap each other and are combined with each other, the dead zone hole 23 of the first heat-transfer plate 20 and the dead zone hole 33 of the second heat-transfer plate 30 may be concentric with each other and may overlap each other in the stacking direction and may communicate with each other.

Referring to FIG. 8, the cover hole 63 formed in the second cover 60, the dead zone hole 23 of the first heat-transfer plate 20, and the dead zone hole 33 of the second heat-transfer plate 30 may overlap each other and communicate with each other in the stacking direction. As a result, when the inspection gas G has been injected from the outside through the cover hole 63, the injected inspection gas G flows into each of the dead zones 22 and 23 through each of the dead zone holes 23 and 33, and thus the fluid-tightness of each of the dead zones may be inspected. Accordingly, the fluid-tightness of the dead zone of the plate heat exchanger may be inspected without forming a gas injection hole in the thin heat-transfer plate.

According to some embodiments, the first and second heat-transfer plates 20 and 30 may be alternately stacked with each other along the stacking direction and may be coupled to each other in a brazing manner. In this regard, the portions around the dead zones 23 and 33 of the first and second heat-transfer plates 20 and 30 may be coupled to each other in a brazing manner.

Dead Zone Fluid-Tightness Inspection

After joining the first and second heat-transfer plates 20 and 30 with each other in the brazing manner, a fluid-tightness inspection of each of the dead zones 22 and 32 may be performed before shipment of the plate heat exchanger.

Each of the dead zones 22 and 32 is an area where there is no fluid flow. However, when there is a defect in the joining of the portions around the dead zones 22 and 32 with each other in the brazing manner, the fluid-tightness of each of the dead zones 22 and 23 may not be maintained. In this case, a gap may be generated between each of the dead zones 22 and 32 and the fluid channel through which the high-temperature first fluid (e.g., water, etc.) flows, and as a result, the high-temperature first fluid (e.g., water, etc.) may flow into each of the dead zones 22 and 32.

However, near the dead zones 22 and 32, there is the fluid channel (i.e., the first heat-transfer plate second fluid inlet, the first heat-transfer plate second fluid outlet, the second heat-transfer plate second fluid inlet, and the second heat-transfer plate second fluid outlet through which the low-temperature second fluid flows into and out of the heat-transfer plate stack).

Thus, the first fluid (e.g., water, etc.) that has flowed into the dead zones 22 and 32 and stagnates therein may freeze due to the low-temperature second fluid (e.g., refrigerant, etc.) flowing through the surrounding area around the dead zone, thereby causing the freezing of the first fluid. This results in serious damage and destruction of the plate heat exchanger. Therefore, after the brazing joining and before shipping of the plate heat exchanger, the fluid-tightness inspection of the dead zones 22 and 32 may be performed in advance to detect any defects.

FIG. 12 and FIG. 13 show an operation of injecting inspection gas through the cover hole of the second cover according to some embodiments.

The inspection gas G may be injected from the outside into the inside of the plate heat exchanger through the cover hole 63.

According to some preferred embodiments, the inspection gas G may include air, helium, etc.

The inspection gas G injected into the inside of the plate heat exchanger 1 through the cover hole 63 may flow into the inside of each of the dead zones through each of the dead zone holes 23 and 33 (see FIG. 8) of the first and second heat-transfer plates 20 and 30 overlapping in the stacking direction the cover hole 63 and communicating therewith. Thereafter, it may be identified whether the inspection gas G flows through the dead zone toward the fluid channel through which the first fluid (e.g., water, etc.) flows. In this way, the fluid-tightness of the dead zone may be inspected and the defect in the brazing joining of the portions around the dead zones may be identified in advance based on the inspection result.

As a result, the brazing joining defect may be identified in advance before the shipment of the plate heat exchanger, thereby increasing product reliability.

FIG. 12 shows the inspection gas G being injected through the cover hole 63 formed in the upper end in the longitudinal direction of the plate heat exchanger 1, that is, the upper end of the second cover 60. FIG. 13 shows the inspection gas G being injected through the cover hole 63 formed in the lower end in the longitudinal direction of the plate heat exchanger 1, that is, the lower end of the second cover 60.

Sealing Structure

FIG. 14 and FIG. 15 are diagrams showing a structure in which after the fluid-tightness inspection of the dead zone, the cover hole is sealed with a sealing to prevent the intrusion of external moisture into the cover hole, according to some embodiments of the present disclosure.

FIG. 14 shows a structure in which the cover hole 63 formed in the upper end in the longitudinal direction of the plate heat exchanger 1, (i.e., the upper end of the second cover 60) is blocked with the sealing 90: 91, 92, and 93 to prevent the intrusion of the outside air into the cover hole.

FIG. 15 shows a structure in which the cover hole 63 formed in the lower end in the longitudinal direction of the plate heat exchanger 1, (i.e., the lower end of the second cover 60) is blocked with the sealing 90: 91, 92, and 93 to prevent the intrusion of the outside air into the cover hole.

The inspection gas G may be injected into the cover hole 63 to determine whether the dead zone is sealed. Upon determination that the dead zone is sealed, it may be determined that there is no defect in the brazing joining between the portions of the plates around the dead zones. Thus, the work of blocking the cover hole 63 with the sealing 90 may be performed.

After the dead zone sealing inspection has been completed, the sealing 90 serves to block the cover hole 63 to prevent the outside air from infiltrating into the inside of the plate heat exchanger. The sealing 90 may seal the cover hole 63 from the outside, and thus, the outside air may no longer invade the inside of the plate heat exchanger through the cover hole 63.

The outside air may contain a certain amount of moisture. When the outside air is introduced into the plate heat exchanger through the cover hole 63, outside moisture contained in the outside air may invade the dead zone through the dead zone hole communicating with the cover hole 63.

When the outside moisture penetrates into the dead zone, the outside moisture may freeze in the dead zone under the influence of the low-temperature second fluid (e.g., refrigerant, etc.), thereby causing the freezing and breakage accident. Therefore, it is necessary to block the cover hole 63 using the sealing 90 after the fluid-tightness inspection of the dead zone has been completed.

The sealing 90 may be formed using various sealing means or sealing schemes that can block the cover hole 63 formed in the second cover 60.

According to some preferred embodiments, the sealing 90 may include a plug 91 that may physically block the cover hole 63 to seal the cover hole 63 from the outside.

The plug 91 may have various shapes and may be inserted into the cover hole 63, for example, in a screw fastening manner or a force fitting manner to block the cover hole 63. The plug 91 may completely prevent the outside air from infiltrating into the dead zone through the cover hole 63 because the dead zone has been sealed with the plug 91 blocking the cover hole 63.

According to some further preferred embodiments, the sealing 90 may include a welding sealing 92. The welding sealing 92 refers to a sealing structure that is obtained by welding the cover hole 63 using each of various welding materials so as to block the cover hole 63.

The second cover 60 has a thickness greater than that of each of the first and second heat-transfer plates 20 and 30 and is made of SUS304 material, and thus has good weldability. Therefore, the cover hole 63 formed in the second cover 60 may be blocked by directly welding the cover hole 63 with the welding material.

According to some further preferred embodiments, the sealing 90 includes a sealing material 93. The sealing material 93 refers to each of various sealing materials (e.g., silicone, etc.) injected into the cover hole 63 to block the cover hole 63.

After the dead zone fluid-tightness inspection has been completed, the sealing material 93 may be easily injected into the cover hole 63 to quickly block the cover hole 63.

Using the various sealings 90: 91, 92, and 93 as descried above to block the cover hole 63, the outside air may no longer penetrate into the inside of the plate heat exchanger after the dead zone inspection has been completed. As a result, the freezing and breakage accident that may occur due to the external moisture penetrating into the dead zone may be prevented in advance.

Although the present disclosure has been described with reference to the accompanying drawings, the present disclosure is not limited by the embodiments disclosed herein and the drawings, and it is obvious that various modifications may be made by those skilled in the art within the scope of the technical idea of the present disclosure. In addition, although the effects based on the configuration of the present disclosure are not explicitly described and illustrated in the description of the embodiment of the present disclosure above, it is obvious that predictable effects from the configuration should also be recognized.