HEAT EXCHANGER

Description

TECHNICAL FIELD

The present invention relates to a heat exchanger, and more particularly, to a heat exchanger that adopts a variable path in consideration of cooling/heating performance to solve a problem in which cooling performance and heating performance vary depending on the number of paths.

BACKGROUND ART

In general, not only components such as an engine for operating a vehicle are provided in an engine room of the vehicle, but also various heat exchangers such as a radiator, an intercooler, an evaporator, and a condenser for cooling the components such as the engine in the vehicle or adjusting an air temperature in an interior of the vehicle are provided in the engine room of the vehicle. In general, heat exchange media flow in the heat exchangers. The heat exchange medium in the heat exchanger exchanges heat with outside air present outside the heat exchanger, such that the cooling operation or the heat dissipation is performed.

A general refrigeration cycle essentially includes a condenser and an evaporator. The condenser is a heat exchanger responsible for condensation in a main refrigeration cycle in an air conditioning system for a vehicle and serves to condense a high-temperature, high-pressure gaseous refrigerant into a liquid state. The evaporator is a heat exchanger responsible for evaporation and serves to evaporate a liquid refrigerant to a gaseous refrigerant, unlike the condenser. In a general cooling mode, the condenser discharges condensation heat, which is generated as the refrigerant is condensed in the condenser, to the outside, whereas the refrigerant in the evaporator absorbs evaporation heat from the outside while being evaporated. The cooling operation is performed by blowing air around the evaporator into the interior by using a process in which the air around the evaporator is cooled by losing heat. Meanwhile, in a heating mode, in addition to a method of directly heating air, a method using a heat pump configured to blow air around the condenser into the interior is sometimes used by using the above-mentioned method in a reverse manner. The cooling mode and the heating mode are performed on the basis of substantially the same principle. A system is also widely used, in which the system is designed to change a flow direction of a refrigerant, and a single heat exchanger operates as an evaporator in the cooling mode and operates as a condenser in the heating mode, such that the cooling and heating operations may be performed by the single heat exchanger.

Meanwhile, the heat exchanger is generally shaped to include a plurality of tubes disposed in parallel with one another so that the refrigerant flows therethrough, and a pair of header tanks provided at two opposite ends of each of tube rows including the tubes. A shape of the heat exchanger, in which a flow of the refrigerant is most simple and easy, is a single route through which the refrigerant introduced into the single header tank performs heat exchange while passing through all the tube rows and is discharged through another header tank. The flow of the refrigerant in the heat exchanger also basically adopts the single route. However, the amount of pressure drop varies depending on a length of a refrigerant propagation route in the heat exchanger, which may cause various problems such as a problem in which a flow rate of the refrigerant cannot be uniformly distributed. Therefore, a design is widely introduced, in which the heat exchanger has two or four routes instead of the single route. For example, Korean Patent No. 2103951 (“Refrigerator,” April 17, 2020) discloses a dual path condenser, and technologies of heat exchangers having multiple paths are variously publicly-known.

FIG. 1 illustrates a flow of a refrigerant in a four-path heat exchanger, and FIG. 2 illustrates a flow of a refrigerant in a two-path heat exchanger. Both the four-path/two-path heat exchangers 40 and 20 illustrated in FIGS. 1 and 2 each include a plurality of tubes 41 and 21 disposed in parallel with one another so that the refrigerant flows therethrough, and a pair of header tanks 42 and 22 provided at two opposite ends of each of tube rows including the tubes 41 and 21. The heat exchangers in FIGS. 1 and 2 are heat exchangers basically used as condensers, and a receiver dryer 10 is connected to the header tank 42 or 22 at one side. Inlet ports 43 and 23/outlet ports 44 and 24, through which the refrigerant is introduced/discharged, are provided in the header tanks 42 and 22. In addition, in order to implement a desired refrigerant flow direction, baffles 45 and 25 are provided at appropriate positions in the header tanks 41 and 21.

A flow of the refrigerant in the four-path heat exchanger 40 will be described specifically with reference to FIG. 1. As illustrated, the refrigerant introduced into the inlet port 43 is condensed in a stepwise manner while flowing in a ‘’ shape sequentially along paths 1, 2, and 3. The refrigerant having passed through path 3 is introduced into the receiver dryer 10, and the gas and the liquid are separated. The liquid refrigerant separated by the receiver dryer 10 is introduced back into path 4 of the four-path heat exchanger 40. The refrigerant, which is overcooled while passing through path 4, is finally discharged to the outlet port 44.

A flow of the refrigerant in the two-path heat exchanger 20 will be described specifically with reference to FIG. 2. As illustrated, the refrigerant introduced into the inlet port 23 is condensed while passing through path 1. The refrigerant having passed through path 1 is introduced into the receiver dryer 10, and the gas and the liquid are separated. The liquid refrigerant separated by the receiver dryer 10 is introduced back into path 2 of the two-path heat exchanger 20. The refrigerant, which is overcooled while passing through path 2, is finally discharged to the outlet port 24.

In case that the four-path/two-path heat exchangers 40 and 20 in FIGS. 1 and 2 operate as condensers in the cooling mode, the four-path heat exchanger 40 has excellent heat transfer performance, a problem with high pressure in the system is solved, and power consumption of a compressor is reduced, such that a coefficient of performance (COP) of the system is improved. However, because the flow path structure of the two-path heat exchanger 20 is relatively simple, heat transfer performance is relatively low, and a problem with high pressure of the system occurs. Further, power consumption of the compressor is increased by the high pressure of the system, which consequently decreases the COP of the system. More specifically, it is known that in the cooling mode, a high pressure of about 4 bar or more is applied, and the COP decreases by about 8% in the two-path heat exchanger 20 in comparison with the four-path heat exchanger 40.

Meanwhile, as described above, a system is widely used in which the single heat exchanger operates as the condenser in the cooling mode and operates as the evaporator in the heating mode. However, in the cooling mode, the performance of the four-path heat exchanger 40 is much higher than the performance of the two-path heat exchanger 40, but in the heating mode, the opposite trend occurs. That is, in case that the four-path/two-path heat exchangers 40 and 20 operate as the evaporators in the heating mode, the flow rate of the refrigerant flowing in the system is low because of a complicated flow path structure of the four-path heat exchanger 40, which degrades the heating performance. In contrast, in the two-path heat exchanger 20, refrigerant flow resistance is low because of the simple flow path structure, and the flow rate of the refrigerant is relatively high, which improves the heating performance. More specifically, it is known that in the heating mode, the flow rate of the refrigerant is as high as 4 to 14 kg/hr, and a heating discharge temperature is high by about 1 to 3 degrees in the two-path heat exchanger 20 in comparison with the four-path heat exchanger 40.

As described above, in case that the single heat exchanger operates as the condenser in the cooling mode and operates as the evaporator in the heating mode, the current heat exchanger structure exhibits excellent performance in any one of the cooling and heating modes, whereas the heat exchanger structure has poor performance in the other of the cooling and heating modes. Accordingly, there is a need to develop a heat exchanger capable of exhibiting excellent performance in both the cooling and heating modes.

DOCUMENT OF RELATED ART

Patent Document

(Patent Document 1) 1. Korean Patent No. 2103951 (“refrigerator”, Apr. 17, 2020)

DISCLOSURE

Technical Problem

The present invention has been made in an effort to solve the above-mentioned problem in the related art, and an object of the present invention is to provide a heat exchanger that adopts a variable path in consideration of cooling/heating performance to solve a problem in which cooling performance and heating performance vary depending on the number of paths. More specifically, another object of the present invention is to provide a heat exchanger that is designed to change the number of paths in consideration of cooling/heating performance so as to be optimized for performance in a cooling mode and performance in a heating mode.

Technical Solution

In order to achieve the above-mentioned object, the present invention provides a heat exchanger 100 including: a plurality of tubes 110 disposed in parallel with one another and configured to define a core region in which a refrigerant flows; a pair of header tanks provided at two opposite ends of the tubes 110; and a plurality of baffles provided in the header tanks, in which a plurality of paths is sequentially disposed in the core region by the plurality of baffles, and a bypass valve, which selectively bypasses some of the plurality of paths, communicates with one side or two sides of the pair of header tanks.

In this case, the heat exchanger 100 may further include a receiver dryer 200, and the bypass valve may be opened or closed depending on a temperature.

In a first embodiment, in the heat exchanger 100, one receiver side bypass valve 160A may be provided as the bypass valve. The refrigerant may not pass through the receiver dryer 200 when the receiver side bypass valve 160A is closed, and the refrigerant may pass through the receiver dryer 200 when the receiver side bypass valve 160A is opened.

In this case, the receiver side bypass valve 160A may be provided above the receiver dryer 200.

In a second embodiment, in the heat exchanger 100, two bypass valves, i.e., a receiver side bypass valve 160A and a flow port side bypass valve 160B may be provided. The refrigerant may not pass through the receiver dryer 200 when the receiver side bypass valve 160A and the flow port side bypass valve 160B are closed. When the receiver side bypass valve 160A and the flow port side bypass valve 160B are opened, a part of the refrigerant may pass through the receiver dryer 200, and the remaining part of the refrigerant may pass through only a part of the heat exchanger 100.

In this case, the receiver side bypass valve 160A may also be provided above the receiver dryer 200. The flow port side bypass valve 160B may be provided between the inlet port 130 and the outlet port 140 formed in the header tank.

In addition, the heat exchanger 100 may include: first and second header tanks 121 and 122; an inlet port 130 provided in the first header tank 121 so that the refrigerant is introduced through the inlet port; an outlet port 140 provided in the first header tank 121 so that the refrigerant is discharged through the outlet port; a first baffle 151 provided in the first header tank 121 at a position between the inlet port 130 and the outlet port 140; a second baffle 152 provided in the second header tank 122 at a position between the first baffle 151 and the outlet port 140; a third baffle 153 provided in the first header tank 121 at a position between the second baffle 152 and the outlet port 140; a fourth baffle 154 provided in the second header tank 122 at the same position as the third baffle 153, in which a region separated by the first baffle 151 defines the first path {circle around (11)}, in which a region between the first baffle 151 and the second baffle 152 defines the second path {circle around (21)}, in which a region between the second baffle 152 and the third and fourth baffles 153 and 154 defines the third path {circle around (31)}, in which a region separated by the third and fourth baffles 153 and 154 defines the fourth path {circle around (41)}, in which the inlet port 130 is formed at a position that communicates with the first path {circle around (11)}, and in which the outlet port 140 is formed at a position that communicates with the fourth path {circle around (4)}.

In addition, the heat exchanger 100 may further include: a receiver dryer 200 connected to any one header tank and configured to receive the refrigerant having passed through the first, second, and third paths {circle around (1)}, {circle around (21)}, and {circle around (31)}, separate the refrigerant into a gaseous refrigerant and a liquid refrigerant, and discharge the liquid refrigerant to the fourth path {circle around (41)}, in which the bypass valve is configured to be opened or closed depending on a refrigerant temperature, in which the bypass valve is closed as a temperature of the refrigerant becomes a relatively high temperature in a cooling mode, and in which the bypass valve is opened as a temperature of the refrigerant becomes a relatively low temperature in a heating mode.

In addition, the heat exchanger 100 may have one receiver side bypass valve 160A as the bypass valve or has two bypass valves, i.e., the receiver side bypass valve 160A and the flow port side bypass valve 160B. In case that the heat exchanger 100 has the receiver side bypass valve 160A, the heat exchanger 100 may include a receiver side bypass port 141 provided in the second header tank 122, and a receiver side bypass path 142 connected to the receiver side bypass valve 160A and configured to allow the refrigerant to bypass the path when the receiver side bypass path 142 is opened. In case that the heat exchanger 100 further has the flow port side bypass valve 160B, the heat exchanger 100 may further include a flow port side bypass port 131 provided in the first header tank 121, and a flow port side bypass path 132 connected to the flow port side bypass valve 160B and configured to allow the refrigerant to bypass the path when the flow port side bypass path 132 is opened.

As an specific example of the first embodiment, in the heat exchanger 100, one receiver side bypass valve 160A may be provided as the bypass valve, the receiver side bypass valve 160A may be provided above the receiver dryer 200, and the refrigerant passing through the first path {circle around (1)} may be supplied to flow to the receiver dryer 200 and pass through the fourth path {circle around (4)} when the receiver side bypass valve 160A is opened.

In this case, in the heat exchanger 100, the receiver side bypass port 141 may be formed at a position on the second header tank 122 that communicates with the first path {circle around (1)}, and the receiver side bypass path 142 may be formed to connect the receiver side bypass valve 160A and the receiver dryer 200.

In the heat exchanger 100, the heat exchanger 100 may operate as a condenser in the cooling mode, and the receiver side bypass valve 160A may be closed, such that the refrigerant passes through all the first, second, third, and fourth paths {circle around (1)}, {circle around (2)}, {circle around (31)}, and {circle around (4)}, and the heat exchanger 100 may operate as an evaporator in the heating mode, the receiver side bypass valve 160A may be opened, and the refrigerant may bypass the second and third paths {circle around (2)} and {circle around (3)} and pass through the receiver dryer 200, such that the refrigerant passes only through the first and fourth paths {circle around (1)} and {circle around (4)}.

As a specific example of the second embodiment, in the heat exchanger 100, a receiver side bypass valve 160A and a flow port side bypass valve 160B may be provided as the two bypass valves, the receiver side bypass valve 160A may be provided above the receiver dryer 200, the flow port side bypass valve 160 may be provided between the inlet port 130 and the outlet port 140, a part of the refrigerant having passed through the first path {circle around (1)} may flow to the receiver dryer and pass through the fourth path {circle around (4)} when the receiver side bypass valve 160A is opened, and the remaining part of the refrigerant having passed through the first path {circle around (1)} may be supplied to pass through the second path {circle around (2)} and be discharged through the flow port side bypass valve 160B when the flow port side bypass valve 160B is opened.

In this case, in the heat exchanger 100, the flow port side bypass port 131 may be formed at a position that communicates with the second path {circle around (2)} on the first header tank 121, the flow port side bypass path 132 may connect the flow port side bypass valve 160B and the outlet port 140, the receiver side bypass port 141 may be positioned at a position that communicates with the first path {circle around (1)} on the second header tank 122, and the receiver side bypass path 142 may connect the receiver side bypass valve 160A and the receiver dryer 200.

In addition, in the heat exchanger 100, in the cooling mode, the heat exchanger 100 may operate as a condenser, and the receiver side bypass valve 160A and the flow port side bypass valve 160B may be closed, such that the refrigerant may pass through all the first, second, third, and fourth paths {circle around (1)}, {circle around (2)}, {circle around (31)}, and {circle around (41)}, and in the heating mode, the heat exchanger 100 may operate as an evaporator, the receiver side bypass valve 160A may be opened, and a part of the refrigerant may bypass the second and third paths {circle around (2)} and {circle around (3)} and pass through the receiver dryer 200, such that a part of the refrigerant passes only through the first and fourth paths {circle around (1)} and {circle around (41)}, and the flow port side bypass valve 160B is opened, such that the remaining part of the refrigerant is discharged immediately after passing through the first and second paths {circle around (1)} and {circle around (2)}.

Advantageous Effects

According to the present invention, the heat exchanger is designed such that the number of paths is changed, as necessary, which may basically solve the problem in which the cooling performance and the heating performance vary depending on the number of paths. In more detail, the four-path/two-path heat exchangers are widely used in the related art. The four-path heat exchanger exhibits excellent performance when the four-path heat exchanger is used as the condenser, and the two-path heat exchanger exhibits excellent performance when the two-path heat exchanger is used as the evaporator. In the present invention, the single heat exchanger uses the bypass valve to change the refrigerant path, such that the heat exchanger operates as the four-path heat exchanger in the cooling mode and the two-path heat exchanger in the heating mode, thereby obtaining all advantages.

In addition, in the present invention, the thermal bypass valve is used to change the refrigerant path by sensing the refrigerant temperature, such that the paths optimized for the cooling and heating modes may be formed. Therefore, it is possible to simply change the heat exchanger path without using a separate electrical signal and electric power and implement the excellent performance in both the cooling and heating modes.

Description of Drawings

FIG. 1 is a view illustrating a flow of a refrigerant in a four-path heat exchanger.

FIG. 2 is a view illustrating a flow of a refrigerant in a two-path heat exchanger.

FIG. 3 is a view illustrating a first embodiment of a heat exchanger of the present invention.

FIG. 4 is a view illustrating a flow of a refrigerant in the first embodiment of the heat exchanger of the present invention in a cooling mode.

FIG. 5 is a view illustrating a flow of the refrigerant in the first embodiment of the heat exchanger of the present invention in a heating mode.

FIG. 6 is a view illustrating a second embodiment of the heat exchanger of the present invention.

FIG. 7 is a view illustrating a flow of the refrigerant in the second embodiment of the heat exchanger of the present invention in the cooling mode.

FIG. 8 is a view illustrating a flow of the refrigerant in the second embodiment of the heat exchanger of the present invention in the heating mode.

FIG. 9 is a view illustrating an operational principle of a thermal valve.

FIG. 10 is a cross-sectional view illustrating a bypass valve of the present invention.

FIG. 11 is a cross-sectional view illustrating an operation of the bypass valve according to the embodiment of the present invention.

DESCRIPTION OF REFERENCE NUMERALS

• • 100: Heat exchanger
  • 110: Tube
  • 121: First header tank
  • 122: Second header tank
  • 130: Inlet port
  • 140: Outlet port
  • 131: Flow port side bypass port
  • 132: Flow port side bypass path
  • 141: Receiver side bypass port
  • 142: Receiver side bypass path
  • 151: First baffle
  • 152: Second baffle
  • 153: Third baffle
  • 154: Fourth baffle
  • 160A: Receiver side bypass valve
  • 160B: Flow port side bypass valve
  • 161: First communication path
  • 162: Second communication path
  • 163: Main space portion
  • 164: Sub-space portion
  • 171: Guide pin
  • 172: Valve cap
  • 172a: Seal ring
  • 172b: Snap ring
  • 173: Casing
  • 174: Elastic portion
  • 175: Cover part
  • 175a: Sealing plate
  • 176: Wax portion
  • 177: Valve plate
  • 177a: Fixing ring
  • 178: Main spring
  • 179: Sub-spring

Mode For Invention

Hereinafter, a heat exchanger according to the present invention, which is configured as described above in consideration of cooling/heating performance, will be described in detail with reference to the accompanying drawings.

[1] Basic Configuration of Heat Exchanger of Present Invention

FIG. 3 illustrates a first embodiment of a heat exchanger of the present invention, and FIG. 6 illustrates a second embodiment of the heat exchanger of the present invention. First, the first and second embodiments are different in positions of a bypass valve. The first and second embodiments will be described below in more detail. A basic configuration of a heat exchanger 100 of the present invention will be described first.

The heat exchanger 100 of the present invention basically has a configuration similar to a four-path heat exchanger. That is, the heat exchanger 100 includes a plurality of tubes 110 disposed in parallel with one another and configured to define a core region in which a refrigerant flows, a pair of header tanks provided at two opposite ends of the tubes 110, and a plurality of baffles provided in the header tanks, and a plurality of paths is sequentially disposed and formed the core region by the plurality of baffles.

As described above, in case that the four-path heat exchanger operates as a condenser in a cooling mode, the four-path heat exchanger has excellent performance in comparison with the two-path heat exchanger. However, in case that the four-path heat exchanger operates as an evaporator in a heating mode, the performance deteriorates because of a complicated route. In view of this configuration, in the present invention, the heat exchanger 100 operates as the four-path heat exchanger in the cooling mode. In contrast, in the heating mode, the bypass valve is used to allow a part of the refrigerant to flow to a simpler route, which solves a problem with the complexity of a route in the four-path heat exchanger in the related art. That is, in the heat exchanger 100 of the present invention, the bypass valve, which selectively bypasses at least some of the plurality of paths, communicates with one side or two opposite sides of the pair of header tanks. In particular, in this case, the heat exchanger 100 further includes a receiver dryer 200, and the bypass valve may be opened or closed depending on a temperature.

The configuration of the heat exchanger 100 will be more specifically described below in detail. One of the pair of header tanks will be referred to as a first header tank 121, and the remaining header tank will be referred to as a second header tank 122. The first header tank 121 has an inlet port 130 into which the refrigerant is introduced, and an outlet port 140 from which the refrigerant is discharged. In addition, first and third baffles 151 and 153 are provided in the first header tank 121, and second and fourth baffles 152 and 154 are provided in the second header tank 122. The first, second, third baffles 151, 152, and 153 are provided at positions sequentially spaced apart from one another and define first, second, and third paths {circle around (1)}, {circle around (2)}, and {circle around (3)}, and the third and fourth baffles 153 and 154 are provided at the same position and define a fourth path {circle around (4)}. That is, the core region is divided by the baffles, and the first, second, third, and fourth paths {circle around (1)}, {circle around (2)}, {circle around (31)}, and {circle around (4)} are sequentially disposed. Meanwhile, the receiver dryer 200 is connected to any one header tank, receives the refrigerant having passed through the first, second, and third paths {circle around (1)}, {circle around (21)}, and {circle around (31)}, separates the refrigerant into a gaseous refrigerant and a liquid refrigerant, and discharges the liquid refrigerant to the fourth path {circle around (4)}

More clearly, the first baffle 151 may be provided in the first header tank 121 and provided at a position between the inlet port 130 and the outlet port 140. The second baffle 152 is provided in the second header tank 122 and provided at a position between the first baffle 151 and the outlet port 140. The third baffle 153 is provided in the first header tank 121 and provided at a position between the second baffle 152 and the outlet port 140. The fourth baffle 154 is provided in the second header tank 122 is provided at the same position as the third baffle 153. Therefore, a region separated by the first baffle 151 defines the first path {circle around (1)}, a region between the first baffle 151 and the second baffle 152 defines the second path {circle around (2)}, and a region between the second baffle 152 and the third and fourth baffles 153 and 154 defines the third path {circle around (3)}, such that the refrigerant defines a ‘’ shape while sequentially passing through the first, second, and third paths {circle around (1)}, {circle around (2)}, and {circle around (3)}. A region separated by the third and fourth baffles 153 and 154 defines the fourth path {circle around (4)}. That is, the fourth path {circle around (4)} is substantially completely isolated from the first, second, and third paths {circle around (1)}, {circle around (21)}, and {circle around (3)}. Meanwhile, the inlet port 130 is formed at a position that communicates with the first path {circle around (11)}, and the outlet port 140 is formed at a position that communicates with the fourth path {circle around (4)}. In this case, because the receiver dryer 200 connects the third path {circle around (3)} and the fourth path {circle around (41)}, the refrigerant may be introduced into the inlet port 130, sequentially pass through the first, second, and third paths {circle around (1)}, {circle around (21)}, and {circle around (31)}, the receiver dryer 200, and the fourth path {circle around (41)}, and be smoothly discharged through the outlet port 140.

This configuration is substantially identical to the configuration of the flow path of the four-path heat exchanger 40 described with reference to FIG. 1. However, in the present invention, as described above, the bypass valve may be used to allow the refrigerant to flow to the four paths in an intact manner or appropriately bypass the four paths in accordance with the cooling and heating modes, such that the performance in the both mode may be improved.

In the present invention, a problem in which a refrigerant flow rate is insufficient in the heating mode is solved by simplifying a route by basically using the bypass valve. A difference in configurations of the bypass valves between the first and second embodiments will be described in more detail.

In the first embodiment, one receiver side bypass valve 160A is provided as the bypass valve. The refrigerant does not pass through the receiver dryer 200 when the receiver side bypass valve 160A is closed, and the refrigerant passes through the receiver dryer 200 when the receiver side bypass valve 160A is opened. In this case, the receiver side bypass valve 160A is provided above the receiver dryer 200 in consideration of a position of a path intended to be bypassed.

In the second embodiment, two bypass valves, i.e., the receiver side bypass valve 160A and a flow port side bypass valve 160B are provided. The refrigerant does not pass through the receiver dryer 200 when the receiver side bypass valve 160A and the flow port side bypass valve 160B are closed. When the receiver side bypass valve 160A and the flow port side bypass valve 160B are opened, a part of the refrigerant passes through the receiver dryer 200, and the remaining part of the refrigerant passes through only a part of the heat exchanger 100. In more detail, a flow of a part of the refrigerant is identical to that in the first embodiment as the receiver side bypass valve 160A is opened or closed. As the flow port side bypass valve 160B is opened or closed, a flow of the remaining part of the refrigerant passes through only a part of the heat exchanger 100, such that the route is simplified. In this case, the receiver side bypass valve 160A is also provided above the receiver dryer 200 in consideration of the position of the path intended to be bypassed. The flow port side bypass valve 160B is provided between the inlet port 130 and the outlet port 140 formed in the header tank.

That is, in both the first and second embodiments, when the bypass valve is closed, the bypass valve supplies the refrigerant so that the refrigerant passes through all the first, second, third, and fourth paths {circle around (1)}, {circle around (2)}, {circle around (31)}, and {circle around (4)}. When the refrigerant is supplied to the first path {circle around (11)}, the refrigerant naturally passes through all the first, second, third, and fourth paths {circle around (1)}, {circle around (2)}, {circle around (31)}, and {circle around (4)}. Therefore, in this case, it can be said that the heat exchanger operates as the four-path heat exchanger. Meanwhile, when the bypass valve is opened, the bypass valve supplies the refrigerant so that the refrigerant passes through only two paths selected from the first, second, third, and fourth paths {circle around (11)}, {circle around (2)}, {circle around (3)}, and {circle around (4)} in both the two embodiments. A difference between the embodiments is which of the two paths the refrigerant passes through. In this case, in the present invention, there is a small difference in that one or two bypass valves may be provided. In addition, a bypass port and a bypass path are further provided in consideration of the presence of a physical distance between the bypass valve and a desired position of the path. Specifically, the heat exchanger 100 has one receiver side bypass valve 160A as the bypass valve or has two bypass valves, i.e., the receiver side bypass valve 160A and the flow port side bypass valve 160B. In case that the heat exchanger 100 has the receiver side bypass valve 160A, the heat exchanger 100 includes a receiver side bypass port 141 provided in the second header tank 122, and a receiver side bypass path 142 connected to the receiver side bypass valve 160A and configured to allow the refrigerant to bypass the path when the receiver side bypass path 142 is opened. In case that the heat exchanger 100 further has the flow port side bypass valve 160B, the heat exchanger 100 further includes a flow port side bypass port 131 provided in the first header tank 121, and a flow port side bypass path 132 connected to the flow port side bypass valve 160B and configured to allow the refrigerant to bypass the path when the flow port side bypass path 132 is opened. A flow of the refrigerant according to the bypass port, the position of the bypass path, and whether the bypass valve is opened or closed will be described in more detail for each embodiment.

[2] First Embodiment of Heat Exchanger of Present Invention

As described above, in the first embodiment, one receiver side bypass valve 160A is provided, and the receiver side bypass valve 160A is provided above the receiver dryer 200. In this case, the receiver side bypass valve 160A supplies the refrigerant so that the refrigerant having passed through the first path {circle around (1)} flows to the receiver dryer 200 and passes through the fourth path {circle around (4)} when the receiver side bypass valve 160A is opened.

Of course, the receiver side bypass port 141 and the receiver side bypass path 142 are also provided while corresponding to the receiver side bypass valve 160A. More specifically, the receiver side bypass port 141 is formed at a position on the second header tank 122 that communicates with the first path {circle around (1)}, and the receiver side bypass path 142 is formed to connect the receiver side bypass valve 160A and the receiver dryer 200.

FIG. 4 illustrates a flow of the refrigerant in the first embodiment of the heat exchanger of the present invention in the cooling mode. In the heat exchanger 100 of the present invention in the first embodiment, the heat exchanger 100 operates as a condenser in the cooling mode, and the receiver side bypass valve 160A is closed, such that the refrigerant passes through all the first, second, third, and fourth paths {circle around (1)}, {circle around (2)}, {circle around (3)},and {circle around (4)}. Therefore, as illustrated in FIG. 4, the refrigerant sequentially passes through the first, second, third, and fourth paths {circle around (1)}, {circle around (2)}, {circle around (31)}, and {circle around (4)}. This flow of the refrigerant is identical to the flow of the refrigerant of the four-path heat exchanger described with reference to FIG. 1. As described above, it is known that the performance is much better when the four-path heat exchanger operates as the condenser (“in the cooling mode, a high pressure of about 4 bar or more is applied, and the COP decreases by about 8% in the two-path heat exchanger 20 in comparison with the four-path heat exchanger 40”). Therefore, in the cooling mode, the heat exchanger 100 generates a flow of the refrigerant identical to the flow of the refrigerant in the general four-path heat exchanger.

FIG. 5 illustrates a flow of the refrigerant in the first embodiment of the heat exchanger of the present invention in the heating mode. In the heat exchanger 100 of the present invention in the first embodiment, the heat exchanger 100 operates as an evaporator in the heating mode, the receiver side bypass valve 160A is opened, and the refrigerant bypasses the second and third paths {circle around (2)} and {circle around (3)} and passes through the receiver dryer 200, such that the refrigerant passes only through the first and fourth paths {circle around (1)} and {circle around (4)}. In more detail, as illustrated in FIG. 5, the refrigerant passing through the first path {circle around (1)} flows to the opened receiver side bypass valve 160A instead of flowing to the second path {circle around (2)}. Therefore, the refrigerant having passed through the receiver dryer 200 immediately passes through the fourth path {circle around (4)} and is discharged. That is, in this case, as a result, the refrigerant passes only through the first and fourth paths {circle around (1)} and {circle around (41)}, such that the heat exchanger 100 operates as if the heat exchanger 100 is a two-path heat exchanger. As described above, in case that the four-path heat exchanger operates as the evaporator, the flow rate of the refrigerant is low because of the complexity of the flow path, and the heating performance deteriorates (“it is known that in the heating mode, the flow rate of the refrigerant is as high as 4 to 14 kg/hr, and a heating discharge temperature is high by about 1 to 3 degrees in the two-path heat exchanger 20 in comparison with the four-path heat exchanger 40”). However, in the heat exchanger 100 of the present invention, the simplification of the route is implemented to allow the refrigerant to pass only through the two paths in the heating mode, thereby obtaining the advantage of the two-path heat exchanger.

[3] Second Embodiment of Heat Exchanger of Present Invention

In the second embodiment, as described above, two bypass valves, i.e., the receiver side bypass valve 160A and the flow port side bypass valve 160B are provided, the receiver side bypass valve 160A is provided above the receiver dryer 200, and the flow port side bypass valve 160B is provided between the inlet port 130 and the outlet port 140. In this case, the receiver side bypass valve 160A supplies the refrigerant so that a part of the refrigerant having passed through the first path {circle around (1)} flows to the receiver dryer 200 and passes through the fourth path {circle around (4)} when the receiver side bypass valve 160A is opened. In addition, the flow port side bypass valve 160B supplies the refrigerant so that the remaining part of the refrigerant passing through the first path {circle around (1)} passes through the second path {circle around (2)} and is discharged through the flow port side bypass valve 160B when the flow port side bypass valve 160B is opened.

Of course, the receiver side bypass port 141, the receiver side bypass path 142, the flow port side bypass port 131, and the flow port side bypass path 132 are also provided while corresponding to the receiver side bypass valve 160A and the flow port side bypass valve 160B. More specifically, in the case of the receiver, as in the first embodiment, the receiver side bypass port 141 is formed at a position on the second header tank 122 that communicates with the first path {circle around (11)}, and the receiver side bypass path 142 is formed to connect the receiver side bypass valve 160A and the receiver dryer 200. Meanwhile, the flow port side bypass port 131 is formed at a position on the first header tank 121 that communicates with the second path {circle around (21)}, and the flow port side bypass path 132 is formed to connect the flow port side bypass valve 160B and the outlet port 140.

FIG. 7 illustrates a flow of the refrigerant in the second embodiment of the heat exchanger of the present invention in the cooling mode. As in the first embodiment, in the heat exchanger 100 of the present invention in the second embodiment, the heat exchanger 100 operates as a condenser in the cooling mode, and the receiver side bypass valve 160A and the flow port side bypass valve 160B are closed, such that the refrigerant passes through all the first, second, third, and fourth paths {circle around (1)}, {circle around (2)}, {circle around (31)}, and {circle around (4)}. Therefore, as illustrated in FIG. 7, the refrigerant sequentially passes through the first, second, third, and fourth paths {circle around (1)}, {circle around (2)}, {circle around (31)}, and {circle around (4)}. This flow of the refrigerant is identical to the flow of the refrigerant in the four-path heat exchanger described with reference to FIG. 1 (and the flow of the refrigerant in the cooling mode in the first embodiment described with reference to FIG. 4).

FIG. 8 illustrates a flow of the refrigerant in the second embodiment of the heat exchanger of the present invention in the heating mode. In the heat exchanger 100 of the present invention in the second embodiment, the heat exchanger 100 operates as an evaporator in the heating mode, the receiver side bypass valve 160A is opened, and a part of the refrigerant bypasses the second and third paths {circle around (2)} and {circle around (3)} and passes through the receiver dryer 200, such that a part of the refrigerant passes only through the first and fourth paths {circle around (1)} and {circle around (41)}, and the flow port side bypass valve 160B is opened, such that the remaining part of the refrigerant is discharged immediately after passing through the first and second paths {circle around (1)} and {circle around (2)}. That is, a part of the refrigerant passes through the receiver dryer 200 and passes only through the two paths, and the remaining part of the refrigerant passes only through a part of the heat exchanger 100 and then is immediately discharged, such that the refrigerant passes only through the two paths. Therefore, in comparison with the first embodiment, the second path {circle around (2)} is further used. In view of the route in terms of the actual flow of the refrigerant, the refrigerant eventually flows only through the two paths, which still appropriately realize the simplification of the route.

It can be said that in comparison with the first embodiment, as in the first embodiment, a route is further added in the second embodiment so that a part of the refrigerant passes only through the first and fourth paths {circle around (1)} and {circle around (4)} and the remaining part of the refrigerant is discharged immediately after passing through the first and second paths {circle around (1)} and {circle around (2)}. In this case, in the case of the first embodiment, the total amount of the refrigerant having passed through the first path {circle around (1)} needs to flow to the receiver dryer 200 through the receiver side bypass valve 160A. However, there is a likelihood that a leak may occur from the route as the refrigerant flowing through a tube disposed below the receiver side bypass valve 160A cannot enter a receiver side bypass route during a process in which the refrigerant is dispersed along several tubes. In this case, the refrigerant, which cannot enter the receiver side bypass route, inevitably passes through all the remaining paths, which inevitably causes a deterioration in performance described above. However, in the case of the second embodiment, even though there is the refrigerant that leaks without entering the receiver side bypass route, the remaining parts of the refrigerant may be collected, pass through the second path {circle around (21)}, and be discharged through the flow port side bypass valve 160B. That is, in the case of the second embodiment, the refrigerant route may be diversified so that there is no leak of the refrigerant. Further, the refrigerant may eventually pass through any route as long as the refrigerant passes only through the two paths, which may effectively remove the factors that cause a deterioration in performance.

[4] Detailed Configuration of Bypass Valve of Present Invention

As described with reference to paragraph [1], in the heat exchanger 100 of the present invention, the paths are changed as the bypass valve is opened or closed in accordance with the modes, such that the path optimized for each of the modes is formed. In this case, the bypass valve may be equipped with an electronic circuit, and a control signal may be applied to adjust the opening or closing of the bypass valve. However, in the present invention, the opening or closing of the bypass valve may be mechanically adjusted in accordance with a temperature of the refrigerant, such that unnecessary components and control algorithm may be additionally removed, which further improves the system efficiency.

First, the operational principle of the valve, which is opened or closed in accordance with the temperature, will be briefly described. FIG. 9 is a view for explaining an operational principle of a thermal valve. As illustrated in FIG. 9, the thermal valve has a shape in which a piston is provided in a housing and surrounded by an elastomer, and a space between the housing and the elastomer is filled with expansion wax. The expansion wax changes into a liquid or solid phase depending on the temperature, with the expansion wax existing as a solid at low temperatures and having a small volume. The left view in FIG. 9 illustrates a state of the thermal valve at a low temperature. Meanwhile, when the temperature environment is raised to a higher temperature, the expansion wax changes to a liquid phase and increases in volume. Because the volume of space in the housing is fixed, any increase in the volume of the expansion wax exerts pressure on the elastomer. This pressure applied to the elastomer causes the piston, which is embedded in the elastomer, to “squeeze”. Therefore, as illustrated in the right view in FIG. 9, the piston is moved in a direction in which the piston is pushed to the outside of the housing. When the temperature environment is lowered to a low temperature again, the expansion wax decreases in volume and naturally returns to the state illustrated in the left view in FIG. 9.

When the piston end is designed to block any flow path hole in the state illustrated in the right view in FIG. 9, the thermal valve in FIG. 9 may operate to close the flow path hole at a high temperature and open the flow path hole at a low temperature. Of course, the flow path may be designed in another way, such that the flow path may be opened at a high temperature, and the flow path may be closed at a low temperature. In this way, the thermal valve does not require any electronic circuitry or control signals, and is able to regulate opening and closing based on purely mechanical principles using only the ambient temperature environment.

FIG. 10 is a cross-sectional view of the bypass valve of the present invention. The principle of the thermal valve described with reference to FIG. 9 is applied to the bypass valve of the present invention illustrated in FIG. 10, such that the opening and closing may be adjusted only on the basis of the purely mechanical principle. That is, the bypass valve is configured to be opened or closed in accordance with the temperature of the refrigerant. Therefore, the bypass valve is closed when the refrigerant has a relatively high temperature in the cooling mode, and the bypass valve is opened when the refrigerant has a relatively low temperature in the heating mode. First, the configuration of the bypass valve will be described in detail with reference to FIG. 10, and then the motions of the components when the bypass valve is opened or closed will be described in detail with reference to FIG. 11.

The bypass valve is connected to a route position, such as the receiver side bypass port 141 or the flow port side bypass port 131, as necessary and receives the refrigerant. The bypass valve includes a first communication path 161 and a second communication path 162 to separate and discharge the refrigerant, as necessary. The first communication path 161 is formed at a position that communicates with the second header tank 122 or the first header tank 121, more clearly, at a position that communicates with the receiver side bypass port 141 or the flow port side bypass port 131. The second communication path 162 is formed at a position connected to the receiver side bypass path 142 or the flow port side bypass path 132. As described above, in the bypass valve in the present invention, in the cooling mode, the bypass valve is closed so that the refrigerant passes through all the first, second, third, and fourth paths {circle around (1)}, {circle around (2)}, {circle around (3)}, and {circle around (4)}. In the heating mode, the bypass valve is opened so that the refrigerant is discharged after passing only through the two selected paths. That is, the first communication path 161 is always opened, and the second communication path 162 is formed to be opened or closed, as necessary.

To this end, first, a main space portion 163 and a sub-space portion 164 are formed in the bypass valve. The main space portion 163 communicates with the inlet port 130 and the first communication path 161 and accommodates a valve part configured to perform the opening and closing operations. The sub-space portion 164 basically communicates with the main space portion 163 and has a smaller cross-sectional area than the main space portion 163. That is, as illustrated in FIG. 10, a stepped portion is formed on a connection portion between the main space portion 163 and the sub-space portion 164, and the valve part is configured to open or close this portion. That is, the communication between the sub-space portion 164 and the main space portion 163 is opened or closed by the operation of the valve part. In this case, because the sub-space portion 164 communicates with the second communication path 162, the opening or closing of the second communication path 162 is adjusted by the operation of the valve part.

The valve part adopts the operational principle of the thermal valve described above with reference to FIG. 9. As illustrated, the valve part may basically include a guide pin 171, a valve cap 172, a casing 173, a cover part 175, an elastic portion 174, a wax portion 176, and a valve plate 177 and further include a main spring 178 and a sub-spring 179 to implement a smoother operation.

The guide pin 171 extends in an extension direction of the main space portion 163 and is provided in the main space portion 163. The guide pin 171 corresponds to a “piston” in FIG. 9. However, in the bypass valve of the present invention, the guide pin 171 is fixed without moving and thus designated to another name.

The valve cap 172 fixes one side of the guide pin 171 to one side of the main space portion 163. A seal ring 172a having an O-ring shape may be provided between the valve cap 172 and an inner wall of the main space portion 163 to prevent a leak. In addition, a snap ring 172b may be provided at an upper end of the valve cap 172 to prevent withdrawal of the valve cap 172.

The casing 173 is formed in a container shape opened at one end thereof and accommodates the guide pin 171. An inner wall of the casing 173 is spaced apart from an outer surface of the guide pin 171. That is, the casing 173 corresponds to the “housing” in FIG. 9. Meanwhile, as described above, the guide pin 171, which corresponds to the “piston” in FIG. 9, is fixed to one side of the main space portion 163 by the valve cap 172. In the thermal valve in FIG. 9, the “housing” is fixed, such that the “piston” is configured to move relative to the “housing” in accordance with the change in temperature. However, in the bypass valve of the present invention in FIG. 10, the guide pin 171 is fixed, and the casing 173 moves relative to the guide pin 171 in accordance with the change in temperature. Meanwhile, as can be seen from the operational principle of the thermal valve in FIG. 9, the operation of the valve is implemented as the wax changes in phase in accordance with the ambient temperature environment. Therefore, the heat transfer between the ambient temperature environment and the wax needs to be actively and appropriately performed. Therefore, the casing 173 may be made of a metallic material that facilitates the heat transfer. For example, the casing 173 may be made of brass or the like.

The elastic portion 174 is provided to surround the guide pin 171 and corresponds to the “elastomer” in FIG. 9. The elastic portion 174 may be made of a material, which is elastically deformed well, to effectively press the guide pin 171. For example, the elastic portion 174 may be made of rubber or the like.

The cover part 175 is movable along the guide pin 171 and serves to seal an open end of the casing 173. In this case, as illustrated in FIG. 10, a structure is formed in which a part of the upper end of the elastic portion 174 is fitted with a lower inner side of the cover part 175. As illustrated, a sealing plate 175a may be provided between the cover part 175 and the elastic portion 174 to prevent foreign substances from being introduced between the elastic portion 174 and the guide pin 171.

The wax portion 176 fills the space between the elastic portion 174 and the casing 173 and changes in phase to a liquid or solid phase in accordance with a temperature. The wax portion 176 corresponds to the “expansion wax” in FIG. 9. In general, it is known that the refrigerant introduced into the condenser in the cooling mode has about 81 degrees or higher, and the refrigerant introduced into the evaporator in the heating mode has about 64 degrees or lower. In view of this, it is preferred that the wax portion 176 is a material that becomes liquid at about 81 degrees or higher and solid at about 64 degrees or lower. As a specific example, the wax portion 176 may be a paraffin-based wax having a characteristic temperature changeable range of 45 degrees to 120 degrees.

The valve plate 177 is provided at the other side of the casing 173 and serves to open or close the communication between the main space portion 163 and the sub-space portion 164. In this case, a fixing ring 177a may be assembled by being press-fitted with a lower side of the valve plate 177 so that the valve plate 177 may be securely fixed to the casing 173.

Two opposite ends of the main spring 177 are respectively supported by the valve plate 177 and one end of the casing 173, and the main spring 177 serves to absorb excessive expansion of the wax portion 176. The components including the guide pin 171 and the valve plate 177 may operate as the thermal valve. However, as the main spring 177 is provided, the operation of the valve may be more stably performed.

Two opposite ends of the restoring spring 179 are respectively supported by the valve plate 177 and the other side of the sub-space portion 164, and the restoring spring 179 serves to assist in restoring the casing 173 to an original position. Even though the restoring spring 179 is not provided, the position of the casing 173 is restored as the wax portion 176 changes to a solid phase. However, the operation of the valve may be more smoothly performed by the restoring force of the restoring spring 179.

FIG. 11 is a cross-sectional view illustrating an embodiment of an operation of the bypass valve of the present invention, in which the top view in FIG. 11 illustrates the cooling mode, and the bottom view in FIG. 11 illustrates the heating mode. FIG. 11 illustrates the embodiment in which the bypass valve is the flow port side bypass valve 160B described above. The first communication path 161 is connected to the flow port side bypass port 131, and the second communication path 162 is connected to the flow port side bypass path 132. The flow port side bypass path 132 is connected to the outlet port 140.

In the cooling mode, i.e., in case that the refrigerant is in a high-temperature state, the flow port side bypass valve 160B operates to be closed, and the valve plate 177 closes the second communication path 162. Therefore, the route along which the refrigerant flows directly to the outlet port 140 is blocked, such that the refrigerant having passed through the first and second paths {circle around (1)} and {circle around (2)} flows to the third and fourth paths {circle around (3)} and {circle around (4)} in an original manner. In the heating mode, i.e., in case that the refrigerant is in a low-temperature state, the flow port side bypass valve 160B operates to be opened, and the valve plate 177 opens the second communication path 162. Therefore, the refrigerant having passed through the first and second paths {circle around (1)} and {circle around (2)} may flow directly to the outlet port 140 along the opened second communication path 162 through the bypass path 132 and be discharged. Therefore, the refrigerant does not flow to the third and fourth paths {circle around (3)} and {circle around (41)}, such that the flow path is further simplified. FIG. 11 illustrates the flow port side bypass valve 160B as an example. However, the receiver side bypass valve 160A may operate in the same way, and only the device or path, through which the refrigerant passes, may be changed. Therefore, a detailed description thereof will be omitted.

The present invention is not limited to the above embodiments, and the scope of application is diverse. Of course, various modifications and implementations made by any person skilled in the art to which the present invention pertains without departing from the subject matter of the present invention claimed in the claims.

INDUSTRIAL APPLICABILITY

The four-path/two-path heat exchangers are widely used in the related art. The four-path heat exchanger exhibits excellent performance when the four-path heat exchanger is used as the condenser, and the two-path heat exchanger exhibits excellent performance when the two-path heat exchanger is used as the evaporator. In the present invention, the single heat exchanger uses the bypass valve to change the refrigerant path, such that the heat exchanger operates as the four-path heat exchanger in the cooling mode and the two-path heat exchanger in the heating mode, thereby obtaining all advantages. In particular, in the present invention, the thermal bypass valve is used to change the refrigerant path by sensing the refrigerant temperature, such that the paths optimized for the cooling and heating modes may be formed. Therefore, it is possible to simply change the heat exchanger path without using a separate electrical signal and electric power.