THERMAL MANAGEMENT SYSTEM AND METHOD OF CONTROLLING THE SAME

Description

FIELD

The disclosure relates to a thermal management system, and more particularly to a method of controlling a thermal management system.

BACKGROUND

Conventional air-conditioning and thermal management systems include a heat exchanger, for example, a plate heat exchanger. Plate heat exchangers consist of stacked plates in which two fluids, for example a refrigerant and/or a coolant, flows through intermediate spaces between adjacent plates, wherein the refrigerant flows from a first side of the plate heat exchanger to the opposite second side of the plate heat exchanger, while the coolant flows parallel to the refrigerant or in the opposite direction from the same end but opposite side or the opposite end to the first end of the plate heat exchanger. The length of the flow channels in the plate heat exchanger corresponds here essentially to the length of the plate heat exchanger from the first end to the second end. The outer dimensions of the plate heat exchanger and the position of the connections of the plate heat exchanger are therefore defining the length of the flow channels in the plate heat exchanger.

Beads, dimples, fins, or various other structures are usually formed and arranged in the flow channels to promote flow uniformity and improved heat transfer through increased surface area. Conventional plate heat exchangers, however, are vulnerable to single and multiple-phase flow maldistribution, at any given flow rates. This phenomenon degrades an effective heat transfer across the plate heat exchanger, which negatively impacts an overall thermal system performance. Typically, the maldistribution of the refrigerant and/or coolant within the plate heat exchanger occurs under low flow rate conditions due to non-uniform and non-homogeneous distribution of the total flow divided across each of the flow channels. A pressure drop resulting from the maldistribution, particularly on the refrigerant side of the plate heat exchanger, limits an operating range of the compressor and affects the overall system efficiency.

Accordingly, it is desirable to develop a thermal management system and a method of controlling the same that improves flow distribution within a heat exchanger of the thermal management system to mitigate against maldistribution of fluids therein, which optimizes a performance of the thermal management system.

SUMMARY

In concordance and agreement with the presently described subject matter, a thermal management system and a method of controlling the same that improves flow distribution within a heat exchanger of the thermal management system to mitigate against maldistribution of fluids therein, which optimizes a performance of the thermal management system, has surprisingly been designed.

In one embodiment, a method for controlling a thermal management system, comprises: providing a thermal management system including a heat exchanger fluidly connected to a first circuit for a first fluid and a second circuit for a second fluid, wherein at least one flow control device is disposed downstream of the heat exchanger in the first circuit and/or the second circuit; and selectively controlling the at least one flow control device to cause an accumulation of the first fluid and/or the second fluid within the heat exchanger.

In another embodiment, a method for controlling a thermal management system, comprises: providing a thermal management system including a heat exchanger fluidly connected to a first circuit for a first fluid and a second circuit for a second fluid; and regulating a flow of the first fluid and/or the second fluid through the heat exchanger, wherein the outflow rate of the first fluid and/or the second fluid is less than a respective one of an inflow rate of the first fluid and/or an inflow rate of the second fluid into the heat exchanger.

In yet another embodiment, a thermal management system, comprises: a first circuit having a flow of a first fluid therein; a second circuit having a flow of a second fluid therein, wherein the second fluid is in thermal energy exchanger relationship with the first fluid; and a heat exchanger fluidly connected to the first circuit and the second circuit, wherein at least one flow control device is disposed downstream of the heat exchanger in the first circuit and/or the second circuit to regulate the flow of the first fluid and/or the flow of the second fluid through the heat exchanger, wherein, in one or more operating modes of the thermal management system, the at least one flow control device is selectively controlled to cause an accumulation of the first fluid and/or the second fluid within the heat exchanger.

As aspects of some embodiments, the first circuit includes a vapor-injection compressor.

As aspects of some embodiments, the first fluid is a refrigerant.

As aspects of some embodiments, the second fluid is a coolant.

As aspects of some embodiments, the heat exchanger is a plate heat exchanger.

As aspects of some embodiments, the heat exchanger is a chiller.

As aspects of some embodiments, the at least one flow control device is selectively controlled depending on a compressor speed, an expansion valve position, and/or an outlet temperature of the second fluid.

As aspects of some embodiments, the at least one flow control device is selectively controlled to provide a liquid free, gaseous (i.e. vapor) phase first fluid to a compressor.

As aspects of some embodiments, in at least one operating mode of the thermal management system, an outflow rate of the first fluid and/or the second fluid from the heat exchanger is less than a respective one of an inflow rate of the first fluid and/or an inflow rate of the second fluid into the heat exchanger.

As aspects of some embodiments, in at least one operating mode of the thermal management system, an outflow rate of the first fluid from the heat exchanger is less than an inflow rate of the first fluid into the heat exchanger.

As aspects of some embodiments, the at least one flow control device is disposed downstream of the heat exchanger in the first circuit.

As aspects of some embodiments, the at least one flow control device is disposed downstream of the heat exchanger in the second circuit.

As aspects of some embodiments, wherein the at least one flow control device is a two-way valve.

As aspects of some embodiments, the at least one flow control device is disposed between the heat exchanger and a compressor in the first circuit.

As aspects of some embodiments, the at least one flow control device is selectively positionable between a fully-opened position, a fully-closed position, and at least one partially-closed position between the fully-opened position and the fully-closed position.

As aspects of some embodiments, the at least one flow control device is selectively positioned in the at least one partially-closed position to cause the accumulation of the first fluid and/or the second fluid within the heat exchanger.

As aspects of some embodiments, the at least one flow control device is selectively positioned in the at least one partially-closed position when a deficiency in an outlet temperature of the second fluid from the heat exchanger in relation to a compressor speed and an expansion valve position and a system efficiency occurs.

As aspects of some embodiments, the at least one flow control device is selectively position in the at least one partially-closed position when a flow rate of the first fluid is relatively low.

Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1 is a schematic diagram of a thermal management system in accordance with an embodiment of the present disclosure, wherein the thermal management system includes two plate heat exchangers and a flow control device disposed downstream of one of the heat exchangers in a first circuit for a first fluid;

FIG. 2 is a schematic diagram of a portion of a thermal management system in accordance with another embodiment of the present disclosure, wherein the thermal management system includes a flow control device disposed downstream of a heat exchanger in a first circuit for a first fluid and another flow control device disposed downstream of the heat exchanger in a second circuit for a second fluid;

FIG. 3 is a schematic view of a heat exchanger and a flow control device for a thermal management system in accordance with the present disclosure, wherein the flow control device is disposed downstream of the heat exchanger in a first circuit for a first fluid and in a fully-opened position during a conventional operating mode of the thermal management system;

FIG. 4 is a schematic view of the heat exchanger and the flow control device illustrated in FIG. 3 showing a level of a liquid-phase first fluid and an accumulation of the liquid-phase first fluid after a first time period, wherein the flow control device is in a partially-closed position during at least one operating mode of the thermal management system according to an embodiment of the present disclosure;

FIG. 5 is a schematic view of the heat exchanger and the flow control device illustrated in FIGS. 3 and 4 showing an increased level of the liquid-phase first fluid and an increased accumulation of the liquid-phase first fluid after a second time period, wherein the flow control device is in a partially-closed position during at least one operating mode of the thermal management system according to an embodiment of the present disclosure and the second time period is greater than the first time period of FIG. 4;

FIG. 6A depicts a maldistribution of a two-phase first fluid within a heat exchanger under conventional methods of operation of a thermal management system during a period of time, wherein a flow control device is in a fully-opened position during all operating modes of the thermal management system and a substantial portion of the heat exchanger, particularly flow channels opposite an inlet port and an outlet port for the first fluid, is not participating in thermal energy transfer between the first fluid and a second fluid;

FIG. 6B depicts an improved distribution of a two-phase first fluid within a heat exchanger under a method of operation of a thermal management system in accordance with an embodiment of the present disclosure after a first time period, wherein a flow control device is in a partially-closed position during at least one operating mode of the thermal management system and a substantial portion or all of the heat exchanger, particularly flow channels opposite an inlet port and an outlet port for the first fluid, is actively participating in thermal energy transfer between the first fluid and a second fluid; and

FIG. 6C depicts an improved distribution of a two-phase first fluid within a heat exchanger under the method of operation of the thermal management system used in FIG. 6B after a second time period, wherein the flow control device is in a partially-closed position during at least one operating mode of the thermal management system and a substantial portion or all of the heat exchanger, particularly flow channels opposite an inlet port and an outlet port for the first fluid, is actively participating in thermal energy transfer between the first fluid and a second fluid, and wherein the second time period is greater than the first time period of FIG. 6B.

DETAILED DESCRIPTION

The following description of technology is merely exemplary in nature of the subject matter, manufacture and use of one or more present disclosures, and is not intended to limit the scope, application, or uses of any specific present disclosure claimed in this application or in such other applications as may be filed claiming priority to this application, or patents issuing therefrom. Regarding methods disclosed, the order of the steps presented is exemplary in nature, and thus, the order of the steps may be different in various embodiments. “A” and “an” as used herein indicate “at least one” of the item is present; a plurality of such items may be present, when possible. Except where otherwise expressly indicated, all numerical quantities in this description are to be understood as modified by the word “about” and all geometric and spatial descriptors are to be understood as modified by the word “substantially” in describing the broadest scope of the technology. “About” when applied to numerical values indicates that the calculation or the measurement allows some slight imprecision in the value (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If, for some reason, the imprecision provided by “about” and/or “substantially” is not otherwise understood in the art with this ordinary meaning, then “about” and/or “substantially” as used herein indicates at least variations that may arise from ordinary methods of measuring or using such parameters.

All documents, including patents, patent applications, and scientific literature cited in this detailed description are incorporated herein by reference, unless otherwise expressly indicated. Where any conflict or ambiguity may exist between a document incorporated by reference and this detailed description, the present detailed description controls.

Although the open-ended term “comprising,” as a synonym of non-restrictive terms such as including, containing, or having, is used herein to describe and claim embodiments of the present technology, embodiments may alternatively be described using more limiting terms such as “consisting of” or “consisting essentially of.” Thus, for any given embodiment reciting materials, components, or process steps, the present technology also specifically includes embodiments consisting of, or consisting essentially of, such materials, components, or process steps excluding additional materials, components or processes (for consisting of) and excluding additional materials, components or processes affecting the significant properties of the embodiment (for consisting essentially of), even though such additional materials, components or processes are not explicitly recited in this application. For example, recitation of a composition or process reciting elements A, B and C specifically envisions embodiments consisting of, and consisting essentially of, A, B and C, excluding an element D that may be recited in the art, even though element D is not explicitly described as being excluded herein.

As referred to herein, all compositional percentages are by weight of the total composition, unless otherwise specified. Disclosures of ranges are, unless specified otherwise, inclusive of endpoints and include all distinct values and further divided ranges within the entire range. Thus, for example, a range of “from A to B” or “from about A to about B” is inclusive of A and of B. Disclosure of values and ranges of values for specific parameters (such as amounts, weight percentages, etc.) are not exclusive of other values and ranges of values useful herein. It is envisioned that two or more specific exemplified values for a given parameter may define endpoints for a range of values that may be claimed for the parameter. For example, if Parameter X is exemplified herein to have value A and also exemplified to have value Z, it is envisioned that Parameter X may have a range of values from about A to about Z. Similarly, it is envisioned that disclosure of two or more ranges of values for a parameter (whether such ranges are nested, overlapping or distinct) subsume all possible combination of ranges for the value that might be claimed using endpoints of the disclosed ranges. For example, if Parameter X is exemplified herein to have values in the range of 1-10, or 2-9, or 3-8, it is also envisioned that Parameter X may have other ranges of values including 1-9, 1-8, 1-3, 1-2, 2-10, 2-8, 2-3, 3-10, 3-9, and so on.

When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” may encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

FIG. 1 illustrates a thermal management system 2 according to an embodiment of the present disclosure. The thermal management system 2 may be employed in a vehicle, for example, a vehicle having an electric motor, in particular a hybrid vehicle or a pure electric vehicle. It is understood, however, that the thermal management system 2 may be used in various other applications including, but not limited to, commercial, industrial, automotive, and residential heating, ventilation, and air conditioning (HVAC) applications.

As depicted, the thermal management system 2 may comprise one or more heat exchangers 10, 100 and one or more flow control devices 12 (e.g., valves, a two-way valve), as best shown in FIG. 1 and described in detail hereinafter. The thermal management system 2 may further comprise more or less components and devices as necessary for operation. In some instances, the thermal management system 2 may further include a compressor 20 (e.g., a single-stage compressor, a vapor-injection compressor), an expansion valve 22, a controller 24, and/or one or more sensors 26.

In some embodiments, the heat exchanger 10 may perform as an evaporator (e.g., a chiller) and the heat exchanger 100 may perform as a condenser (e.g., a water-cooled condenser (WCC)). The heat exchangers 10, 100 are depicted as plate heat exchangers, however, it is understood that each of the heat exchangers 10, 100 may be other various types of heat exchangers if desired. The heat exchanger 10 may be fluidly connected and/or in fluid communication with a first circuit 14 for a first fluid (e.g., a refrigerant, coolant, etc.) and a second circuit 16 for a second fluid (e.g. a refrigerant, a coolant, etc.). Likewise, the heat exchanger 100 may be fluidly connected and/or in fluid communication with the first circuit 14 for the first fluid and a third circuit 18 for a third fluid (e.g. a refrigerant, a coolant, etc.). It should be appreciated that each of the fluids may have any desired pressure. For example, the first fluid may be a high-pressure fluid and the second and/or third fluids may be a low-pressure fluid. The heat exchanger 10 being integrated into the first circuit 14 and the second circuit 16 permits the first fluid to transfer thermal energy between the first fluid and the second fluid. Similarly, the heat exchanger 100 being integrated in the first circuit 14 and the third circuit 18 permits the first fluid to transfer thermal energy between the first fluid and the third fluid. In preferred embodiments, the heat exchanger 10 permits the first fluid (e.g., the refrigerant) to be vaporized by the second fluid (e.g., the coolant) prior to entering the compressor 20 and the heat exchanger 100 permits the first fluid (e.g., the refrigerant) to be cooled by the third fluid (e.g., the coolant) after exiting the compressor 20.

FIGS. 2-5 illustrate an exemplary embodiment of the heat exchanger 10. It is understood that structure of the heat exchanger 100 may be substantially similar or the same as that of the heat exchanger 10, and for simplicity, a detailed description is not repeated herein.

In some embodiments, the heat exchanger 10 comprises a plurality of first plates 30 and a plurality of second plates 31 alternatingly arranged one on top of each other in a stacked relationship between opposing end plates 32, 34. It is understood that one or more of the end plates 32, 34 may be part of a housing of the heat exchanger 10 if desired. It is understood that the heat exchanger 10 may include any number of the plates 30, 31 as desired.

Inlet ports 36, 38 and corresponding outlet ports 40, 42 may formed in one of the end plates 32, 34. In some embodiments, the inlet port 36 and the outlet port 40 may be fluidly connected to the first circuit 14 for a flow of the first fluid through the heat exchanger 10, and the inlet port 38 and the outlet port 42 may be fluidly connected to the second circuit 16 for a flow of the second fluid through the heat exchanger 10. One or more of the inlet ports 36, 38 and the outlet ports 40, 42 may be integrally formed with the one of the end plates 32, 34. Yet, in other embodiments, one or more of the inlet ports 36, 38 and the outlet ports 40, 42 may be formed as separate and distinct components that are coupled to the one of the end plates 32, 34. Each of the first and second plates 30, 31 and/or each of the end plates 32, 34 may be substantially elongate and rectangular. However, it is understood that the first and second plates 30, 31 and the end plates 32, 34 may have various shapes, sizes, and configurations as desired.

In preferred embodiments, each of the first and second plates 30, 31 includes an inflow opening and an outflow opening for the first fluid formed therein. The inflow openings of the plates 30, 31 may be in fluid communication with each other to form an inlet manifold for the first fluid, which may be fluidly connected to the inlet port 36. Likewise, the outflow openings may be in fluid communication with each other to form an outlet manifold for the first fluid, which is fluidly connected to the outlet port 40. The inflow openings and the outflow openings may be diagonally, opposed being located in diagonally, opposite corners of the respective first and second plates 30, 31. Thus, a distance from the inflow openings to the outflow openings that the first fluid has to travel may be maximized.

Each of the first and second plates 30, 31 further includes an inflow opening and an outflow opening for the second fluid formed therein. The inflow openings of the plates 30, 31 may be in fluid communication with each other to form an inlet manifold for the second fluid, which may be fluidly connected to the inlet port 38. Likewise, the outflow openings may be in fluid communication with each other to form an outlet manifold for the second fluid, which is fluidly connected to the outlet port 42. The inflow openings and the outflow openings may be diagonally, opposed being located in diagonally, opposite corners of the respective first and second plates 30, 31. Thus, a distance from the inflow openings to the outflow openings that the second fluid has to travel may be maximized.

It is understood that each of the inflow openings and the outflow openings may be located elsewhere in the respective first and second plates 30, 31 to achieve a desired thermal energy exchange between the first fluid and the second fluid.

As depicted in FIGS. 2-5, the plates 30, 31 may be configured to define one or more flow channels 44 for the first fluid (depicted schematically by solid lines in FIGS. 3-5) and one or more flow channels 46 for the second fluid (depicted schematically by dashed lines in FIGS. 3-5). As best shown in FIG. 2, the flow channels 44 and the flow channels 46 may be formed alternately between the plates 30, 31. It is understood, however, that other arrangements of the flow channels 44, 46 within the heat exchanger 10 may be employed. At least one thermal energy transfer device, for example, fins, may be disposed in at least a portion of at least one of the flow channels 44, 46 to enhance and improve a rate of thermal energy transfer between the first fluid and the second fluid within the heat exchanger 10.

Accordingly, the first fluid from the first circuit 14 may flow into the inlet port 36, through the inflow openings and the inlet manifold, through a substantial portion or an entirety of the heat exchanger 10, via the flow channels 44, where an exchange of thermal energy occurs between the first fluid and the second fluid, through the outlet openings and the outlet manifold, and from the outlet port 40 back into the first circuit 14. Similarly, the second fluid from the second circuit 16 may flow into the inlet port 38, through the inflow openings and the inlet manifold, through a substantial portion or an entirety of the heat exchanger 10, via the flow channels 46, where an exchange of thermal energy occurs between the first fluid and the second fluid, through the outlet openings and the outlet manifold, and from the outlet port 42 back into the second circuit 16.

Optionally, one or more of the heat exchangers 10, 100 may further include a fluid level mechanism configured to indicate a level of the first fluid in a liquid phase therewithin.

In some embodiments, at least one of the flow control devices 12 may located downstream of at least one of the heat exchangers 10, 100 in the first circuit 14 (as shown in FIG. 1). In other embodiments, at least one of the flow control devices 12 may be located downstream of at least one of the heat exchangers 10, 100 in the first circuit 14 and the second circuit 16 and/or the third circuit 18 (as shown in FIG. 2). In yet other embodiments, at least one of the flow control devices 12 may be located downstream of at least one of the heat exchangers 10, 100 in the second circuit 16 and/or the third circuit 18. Various other locations of the flow control devices 12 relative to the heat exchangers 10, 100 in the circuits 14, 16, 18 may be employed if desired.

The flow control devices 12 are configured to be selectively controlled to regulate the flow of the first fluid and/or second fluid into and/or from one or more of the heat exchangers 10, 100. In some embodiments, at least one of the flow control devices 12 is selectively controlled to create a backflow pressure and reduce an outflow rate of the first fluid and/or second fluid from one or more of the heat exchangers 10, 100, thereby improving flow distribution and mitigating maldistribution within the one or more heat exchangers 10, 100. A substantial portion or all of the one or more of the heat exchangers 10, 100, particularly the flow channels 44 opposite the inlet port 36 and the outlet port 40 for the first fluid, are actively participating in thermal energy transfer between the first and second fluids. As a result, the first fluid, in only a gaseous phase (i.e., vapor), flows from the heat exchanger 10 to the compressor 20 in the first circuit 14. Preferably, at least one of the flow control devices 12 may be selectively controlled so that, in one or more operating states of the thermal management system 2, the outflow rate of the first fluid and/or second fluid from one or more of the heat exchangers 10, 100 is less than an inflow rate of the first fluid and/or second fluid into one or more of the heat exchangers 10, 100. Thus, an accumulation of the first fluid and/or the second fluid (i.e., a “flooding”) within the respective flow channels 44, 46 of the one or more of the heat exchangers 10, 100 occurs over time.

In preferred embodiments, at least one of the flow control devices 12 may be configured to be selectively positionable between a fully-opened position, a fully-closed position, and one or more partially-closed positions between the fully-opened and the fully-closed positions. In at least one operating mode of the thermal management system 2, the at least one flow control device 12 may be positioned in the fully-opened position so that the outflow rate of the first fluid and/or the second fluid from one or more of the heat exchangers 10, 100 is substantially equal to the inflow rate of the first fluid and/or the second fluid into the one or more of the heat exchangers 10, 100. Additionally, in at least one operating mode of the thermal management system 2, the at least one flow control device 12 may be positioned in one of the partially-closed positions to create a backflow pressure in one or more of the heat exchangers 10, 100. In at least one operating mode of the thermal management system 2, the at least one flow control device 12 may be positioned in one of the partially-closed positions so that the outflow rate of the first fluid and/or the second fluid from one or more of the heat exchangers 10, 100 is less than the inflow rate of the first fluid and/or the second fluid into the one or more of the heat exchangers 10, 100. Although a method of operating the thermal management system 2 of the present disclosure, described in detail hereinafter, does not include an operating mode thereof that employs the at least one flow control device 12 in the fully-closed position, it may remain possible.

Referring back to FIG. 1, the sensors 26 may be employed in the thermal management system 2 to detect and/or measure various parameters of the thermal management system 2. The sensors 26 may be in communication (e.g., wired and/or wireless) with the controller 24. In some embodiments, at least one of the sensors 26 may be located upstream of at least one of the heat exchangers 10, 100 in the first circuit 14 to detect and/or measure the flow rate and/or a temperature of the first fluid entering into the heat exchangers 10, 100. Similarly, at least one of the sensors 26 may be located downstream of at least one of the heat exchangers 10, 100 in the first circuit 14 to detect and/or measure the outflow rate and/or a temperature of the first fluid exiting from the heat exchangers 10, 100. Additionally, at least one of the sensors 26 may be located upstream of the heat exchanger 10 in the second circuit 16 and/or upstream of the heat exchanger 100 in the third circuit 18 to detect and/or measure the inflow rate and/or a temperature of the respective second fluid and/or the third fluid entering into the heat exchangers 10, 100. Similarly, at least one of the sensors 26 may be located downstream of the heat exchanger 10 in the first circuit 14 and/or downstream of the heat exchanger 100 in the third circuit 18 to detect and/or measure the outflow rate and/or a temperature of the respective second fluid and/or the third fluid exiting from the heat exchangers 10, 100. It should be appreciated that the sensors 26 may be located elsewhere in the thermal management system 2 and may be any suitable type of sensor as desired.

As illustrated, the controller 24 may also be in wired and/or wireless communication with various other components and devices of the thermal management system 2 to control an operation thereof. In some embodiments, the controller 24 may be in communication with at least one of the flow control devices 12 to selectively control the inflow rate and/or the outflow rate of the first fluid and/or the second fluid of one or more of the heat exchangers 10, 100. Additionally, the controller 24 may be in communication with the compressor 20 to control a speed thereof. In certain instances, the controller 24 may control various components and devices of the thermal management system 2 based upon signals and/or data received from the sensors 26.

Under conventional methods of operation of the thermal management system 2, maldistribution of the first fluid occurs within a heat exchangers, especially during low mass flow rates of the first fluid. FIGS. 3 and 6A depict such maldistribution of the first fluid within the one or more heat exchangers 10, 100 under the conventional methods of operation (i.e., the flow control device 12 in the fully-opened position during all operating modes of the thermal management system 2). As best depicted by the solid lines in FIG. 3, the first fluid does not flow through a substantial number of the flow channels 44 opposite the inlet and outlet ports 36, 40 when the flow control device 12 is in the fully-opened position. FIG. 6A illustrates a liquid volume fraction for a two-phase fluid within the one or more heat exchangers 10, 100, when the flow control device 12 is in the fully-opened position, after a period of time. As depicted in FIGS. 3 and 6A, a substantial portion of the one or more heat exchangers 10, 100, under the conventional methods of operation of the thermal management system 2, is not participating in thermal energy transfer between the first and second fluids.

An improved distribution of the first fluid occurs within the one or more heat exchangers 10, 100 under a method of operation of the thermal management system 2 in accordance with an embodiment present disclosure. FIGS. 4, 5, 6B, and 6C illustrate an improved distribution of a two-phase first fluid within one or more of the heat exchangers 10, 100 under an exemplary inventive method of operation of the thermal management system 2. As best illustrated by the solid lines in FIGS. 4 and 5, the first fluid flows through a substantial number of the flow channels 44, including those flow channels 44 opposite the inlet and outlet ports 36, 40, when the flow control device 12 is in the partially-closed position. Additionally, FIG. 4 shows a level of the liquid-phase first fluid and an accumulation of the liquid-phase first fluid (depicted by cross-hatching) within the flow channels 44 after a first time period t₁ (i.e., t₁>0), and FIG. 5 shows an increased level of the liquid-phase first fluid and an increased accumulation of the liquid-phase first fluid with the flow channels 44 after a second period time t₂, wherein the second time period to is greater than the first time period ty (i.e., t₂>t₁>0). FIGS. 6B and 6C illustrate a liquid volume fraction for a two-phase fluid within the one or more heat exchangers 10, 100, when the flow control device 12 is in the partially-closed position, after the first time period t₁ and after the second time period t₂, respectively. As depicted in FIGS. 4, 5, 6B, and 6C, a substantial portion or all of the one or more of the heat exchangers 10, 100, particularly the flow channels 44 opposite the inlet port 36 and the outlet port 40 for the first fluid, is actively participating in thermal energy transfer between the first fluid and a second fluid.

The method of operation of the thermal management system 2 of the present disclosure may include selectively controlling one or more of the flow control devices 12 to create a backflow pressure in one or more of the heat exchangers 10, 100 and/or to regulate the flow of the first fluid and/or the second fluid so that the outflow rate of the first fluid and/or the second fluid from one or more of the heat exchangers 10, 100 is less than the inflow rate of the first fluid and/or the second fluid into the one or more of the heat exchangers 10, 100. In preferred embodiments, the method includes selectively positioning at least one of the flow control devices 12 in the partially-closed position to achieve the desired results.

In some embodiments, the method of operation of the thermal management system 2 may be dependent on and be a function of various components thereof, for example, the speed of the compressor 20, a position of the expansion valve 22, and the temperature of the second fluid for one of the heat exchangers 10, 100. In a non-limiting example, the at least one of the flow control devices 12 is selectively positioned, via the controller 24, in the partially-closed position when maldistribution is identified by a deficiency in the temperature of the second fluid exiting the heat exchanger 10 relative to the speed of the compressor 20 and the position of the expansion valve 22. Alternatively, the at least one of the flow control devices 12 is selectively positioned, via that controller 24, in the fully-opened or less partially-closed position when maldistribution is not identified by the deficiency in the temperature of the second fluid exiting the heat exchanger 10 relative to the speed of the compressor 20 and the position of the expansion valve 22.

In some embodiments, the method of operation of the thermal management system 2 may be independent of various components thereof, for example, a flow arrangement of the first and second fluids, a size, orientation, and layout of the heat exchangers 10, 100 with respect to gravity, sizes of the inlet ports 36, 38 and/or the outlet ports 40, 42, and the like.

Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms, and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. Equivalent changes, modifications and variations of some embodiments, materials, compositions and methods can be made within the scope of the present technology, with substantially similar results.