Parallel evaporator heat exchange system architecture and control methods

Abstract

A heat exchange system includes at least two evaporators that are fluidically coupled together in parallel and a compressor that is fluidically coupled with the at least two evaporators. The heat exchange system additionally includes a condenser that is fluidically coupled with the at least two evaporators. The heat exchange system further includes downstream flow regulators each fluidically coupled to a corresponding one of the at least two evaporators at a location downstream of the corresponding one of the at least two evaporators, and each configured to regulate flow between the corresponding one of the at least two evaporators and the compressor. The heat exchange system also includes only one upstream flow regulator fluidically coupled to the at least two evaporators at a location upstream of the at least two evaporators. The upstream flow regulator is configured to regulate fluid superheat to the compressor.

Description

PARALLEL EVAPORATOR HEAT EXCHANGE SYSTEM ARCHITECTURE AND CONTROL METHODSCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 665,686, filed June 28, 2024, which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates generally to heat exchange systems and more particularly to heat exchange systems having parallel evaporators.BACKGROUND

[0003] Conventional parallel evaporator heat exchange systems provide heat transfer functionality using vapor compression techniques. Parallel evaporator heat exchange systems include at least two evaporators, a compressor, and a condenser. The evaporators are fluidically coupled in parallel and configured to receive a fluid that has been partially flashed to a two-phase fluid through an expansion valve after the condenser, transfer heat from the environment or heat load to evaporating fluid within the evaporators, and provide cool low- pressure gas to the compressor. Parallel evaporator heat exchange systems also include flow regulators that control the flow rate of fluid through the system.

[0004] Some parallel evaporator heat exchange systems rely on an overly high quantity of flow regulators to control flow rate and fluid state. The high part count of such systems increases the cost, weight, volumetric footprint, and unreliability of the systems. Other parallel evaporator heat exchange systems have an overly low quantity of flow regulators, and instead rely on complex control systems to control the flow rate and fluid state of fluid flowing through the system. However, the low part count and complex control systems of such systems, although potentially promoting a cheaper, lighter, and more reliable system, also negatively affect performance by creating the potential for conflicting control demands, resulting in instabilities or excessive design timelines.SUMMARY

[0005] The subject matter of the present application has been developed in response to the present state of the art, and in particular, in response to the shortcomings of traditional parallel evaporator heat exchange systems and methods, which have not yet been fully solved by currently available techniques. Accordingly, the subject matter of the present application has been developed to provide examples of a parallel evaporator heat exchange system, andassociated method, which overcome at least some of the above-discussed shortcomings of prior art techniques.

[0006] According to one example, a heat exchange system includes at least two evaporators that are fluidically coupled together in parallel. The heat exchange system also includes a compressor that is fluidically coupled with the at least two evaporators so that the compressor supplies a fluid to the at least two evaporators. The heat exchange system additionally includes a condenser that is fluidically coupled with the at least two evaporators so that the fluid is supplied to the condenser from at least one of the at least two evaporators. The heat exchange system further includes downstream flow regulators each fluidically coupled to a corresponding one of the at least two evaporators at a location downstream of the corresponding one of the at least two evaporators. Each one of the downstream flow regulators is configured to regulate flow between the corresponding one of the at least two evaporators and the compressor. The heat exchange system also includes only one upstream flow regulator fluidically coupled to the at least two evaporators at a location upstream of the at least two evaporators. The upstream flow regulator is configured to regulate fluid superheat to the compressor.

[0007] According to another example, a method of exchanging heat between at least two environments includes compressing a fluid, in a superheated vapor state, so that a pressure and temperature of the fluid increases. The method also includes removing heat from the fluid in the superheated vapor state, after the fluid is compressed, so that the fluid changes from the superheated vapor state to a saturated or subcooled liquid state. The method additionally includes passing the fluid in the saturated or subcooled liquid state through a single upstream flow regulator so that the fluid changes from the saturated or subcooled liquid state to a liquid-vapor state. The method further includes adding heat to the fluid in the liquid-vapor state, by passing the fluid in the liquid-vapor state through at least two evaporators in parallel, so that fluid changes from the liquid-vapor state to the superheated vapor state. The method also includes independently controlling a flow rate of the fluid through the at least two evaporators by passing the fluid exiting the at least two evaporators through a corresponding one of at least two downstream flow regulators.

[0008] The described features, structures, advantages, and / or characteristics of the subject matter of the present disclosure may be combined in any suitable manner in one or more examples and / or implementations. In the following description, numerous specific details are provided to impart a thorough understanding of examples of the subject matter of the present disclosure. One skilled in the relevant art will recognize that the subject matter of the presentdisclosure may be practiced without one or more of the specific features, details, components, materials, and / or methods of a particular example or implementation. In other instances, additional features and advantages may be recognized in certain examples and / or implementations that may not be present in all examples or implementations. Further, in some instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the subject matter of the present disclosure. The features and advantages of the subject matter of the present disclosure will become more fully apparent from the following description and appended claims, or may be learned by the practice of the subject matter as set forth hereinafter.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order that the advantages of the subject matter may be more readily understood, a more particular description of the subject matter briefly described above will be rendered by reference to specific examples that are illustrated in the appended drawings. Understanding that these drawings, which are not necessarily drawn to scale, depict only certain examples of the subject matter and are not therefore to be considered to be limiting of its scope, the subject matter will be described and explained with additional specificity and detail through the use of the drawings, in which:

[0010] Figure 1 is a schematic flow diagram of a heat exchange system, according to one or more examples of the present disclosure;

[0011] Figure 2 is a schematic flow diagram of another heat exchange system, according to one or more examples of the present disclosure;

[0012] Figure 3 is a schematic flow diagram of yet another heat exchange system, according to one or more examples of the present disclosure; and

[0013] Figure 4 is a controls block diagram of a compressor speed control system, according to one or more examples of the present disclosure.DETAILED DESCRIPTION

[0014] Reference throughout this specification to "one example," "an example," or similar language means that a particular feature, structure, or characteristic described in connection with the example is included in at least one example of the present disclosure. Appearances of the phrases "in one example," "in an example," and similar language throughout this specification may, but do not necessarily, all refer to the same example. Similarly, the use of the term "implementation" means an implementation having a particular feature, structure, or characteristic described in connection with one or more examples of the present disclosure,however, absent an express correlation to indicate otherwise, an implementation may be associated with one or more examples.

[0015] Disclosed herein are examples of a parallel evaporator heat exchange system having, and associated architecture and control methods utilizing, a proper quantity of flow regulators for controlling flow rate and fluid state without sacrificing performance. The term heat exchange system can be used interchangeably with parallel evaporator heat exchange system or parallel evaporator vapor compression system (VCS). Flow regulators are used in the heat exchange system to help ensure complete transition of fluid in evaporators from liquid to gas before entering a compressor. According to some examples, the parallel evaporator heat exchange system includes a single upstream flow regulator upstream of the parallel evaporators and a downstream flow regulator corresponding with each one of the parallel evaporators. The single upstream flow regulator, being dedicated to controlling the fluid state of the fluid exiting the evaporator to ensure proper superheat before entering the compressor of the system, and the downstream flow regulators, being dedicated to controlling the flow rate of fluid through the parallel evaporators, avoids conflicting control commands while keeping the part count relatively low. Additionally, the lower part count of the parallel evaporator heat exchange system disclosed herein, which is facilitated by the use of a single upstream flow regulator, also helps to decrease cost, weight, volumetric footprint, and unreliability. Moreover, the parallel evaporator heat exchange system promotes scalability, via an increase in the number evaporators, without a corresponding increase in the number of upstream flow regulators.

[0016] Referring to Figure 1, one example of a heat exchange system 100A is shown. The heat exchange system 100 A includes a first evaporator 102 A and a second evaporator 102B fluidically coupled together in parallel. As used herein, two or more evaporators are fluidically coupled together in parallel when the two or more evaporators receive fluid from respective divided input branches of a common input conduit or splitter and provide fluid to respective output branches that merge into a common output conduit or mix point. As shown in Figure 1, a common input conduit 110 of the heat exchange system 100A is fluidically coupled with a condenser of the heat exchange system 100 A so that the common input conduit 110 receives fluid from the condenser. Accordingly, the first evaporator 102 A and the second evaporator 102B receive respective portions of fluid passed through the condenser via a first input branch 112A and a second input branch 112B, respectively, of the heat exchange system 100A. A common output conduit 114 of the heat exchange system 100A is fluidically coupled with a compressor 108 of the heat exchange system 100 A. Therefore,fluid passing through the first evaporator 102A and the second evaporator 102B is supplied to a first output branch 116A and a second output branch 116B, respectively, of the heat exchange system 100A. From the first output branch 116A and the second output branch 116B the fluid is combined in the common output conduit 114 and supplied to the compressor 108.

[0017] The heat exchange system 100A, and the other heat exchange systems disclosed herein, are configured to execute a vapor-compression cycle. In terms of the heat exchange system 100 A, the vapor-compression cycle includes driving a fluid (e.g., refrigerant) through the heat exchange system 100A via operation of the compressor 108. The compressor 108 is powered by an electrical input and, when in operation, draws the fluid into the compressor 108 as a superheated vapor (i.e., cool low-pressure gas or low superheated vapor) and compresses the fluid so that the pressure of the superheated vapor substantially increases and the temperature of the superheated vapor substantially increases due to the heat of compression. The compressed vapor sheds heat to a first environment as it passes through the condenser, which changes the state of the fluid from a superheated vapor to a saturated or sub-cooled liquid (i.e., warm high-pressure liquid). The saturated or sub-cooled liquid passes through a flow regulator or expansion valve, described below, which changes the state of the fluid from the liquid state to a liquid-vapor mixture (i.e., cold low-pressure liquid-vapor mixture), before entering one of the first evaporator 102 A or the second evaporator 102B. The liquid-vapor mixture receives heat from a second environment (resulting in a cooling of the second environment) as it passes through the first evaporator 102 A or from a third environment as it passes through the second evaporator 102B, which changes the state of the liquid-vapor mixture to the superheated vapor in preparation for entering and being compressed by the compressor 108 to restart the vapor-compression cycle.

[0018] The heat exchange system 100A also includes a first upstream flow regulator 104 A, a second upstream flow regulator 104B, a first downstream flow regulator 106 A, and a second downstream flow regulator 106B. The first upstream flow regulator 104A is fluidically coupled to (e.g., situated within) the first input branch 112A and operable to control the flow rate of the fluid entering the first evaporator 102 A and thus the superheated state of the fluid exiting the first evaporator 102 A. Similarly, the second upstream flow regulator 104B is fluidically coupled to (e.g., situated within) the second input branch 112B and operable to control the flow rate of the fluid entering the second evaporator 102B and thus the superheated state of the fluid exiting the second evaporator 102B. The first upstream flow regulator 104 A and the second upstream flow regulator 104B are expansion valves insome examples. Generally, the first upstream flow regulator 104A and the second upstream flow regulator 104B are operable to ensure the fluid exiting the first evaporator 102 A and the second evaporator 102B, and thus the fluid entering the compressor 108, is a low superheated vapor (i.e., in a gaseous state). In other words, the first upstream flow regulator 104A and the second upstream flow regulator 104B are operable to ensure the fluid entering the first evaporator 102A and the second evaporator 102B is in the liquid-vapor state and will transition into the saturated vapor or low superheated vapor state when heated within the first evaporator 102 A and the second evaporator 102B. For example, an upstream flow regulator can be more closed, to enable more expansion of the liquid from the condenser and a lower liquid content in the liquid-vapor exiting the upstream flow regulator (with lower temperature). Conversely, an upstream flow regulator can be open wider, to enable less expansion of the liquid from the condenser and a higher liquid content in the liquid-vapor exiting the upstream flow regulator. The superheated characteristics of the fluid exiting the first evaporator 102 A and the second evaporator 102B can be different and are individually controlled so that when the portions of the fluid are combined in the common output conduit 114, the fluid in the common output conduit 114 is superheated to a desirable level.

[0019] The first downstream flow regulator 106A is fluidically coupled to (e.g., situated within) the first output branch 116A and operable to control the flow rate of fluid flowing through the first evaporator 102A, which directly controls the cooling capacity of the first evaporator 102A. Similarly, the second downstream flow regulator 106B is fluidically coupled to (e.g., situated within) the second output branch 116B and operable to control the flow rate of fluid flowing through the second evaporator 102B, which directly controls the cooling capacity of the second evaporator 102B.

[0020] Because each one of the first upstream flow regulator 104 A, the second upstream flow regulator 104B, the first downstream flow regulator 106 A, and the second downstream flow regulator 106B has a dedicated control mode, the flow regulators of the heat exchange system 100 A do not require complex switching between superheat and cooling capacity controls. Accordingly, this configuration can result in simpler and more stable controls, which in turn promotes a more efficient vapor-compression cycle. However, as presented above, because the heat exchange system 100 A has dedicated upstream and downstream flow regulators for each one of the evaporators, the heat exchange system 100 A has a high part count. High part counts in systems, particularly in aeronautical or aerospace applications, can negatively affect weight, volumetric footprint, reliability, and recurring costs. Additionally, because both an upstream flow regulator and a downstream flow regulator must be added foreach additional evaporator added to the heat exchange system 100 A, the heat exchange system 100A is not easily and efficiently scalable.

[0021] Referring to Figure 2, another example of a heat exchange system 100B is shown. The heat exchange system 100B is similar to the heat exchange system 100A of Figure 1, with like numbers referring to like elements. For example, the heat exchange system 100B includes a first evaporator 102 A and a second evaporator 102B fluidically coupled together in parallel. The heat exchange system 100B also includes a common input conduit 110 or splitter that is split or divided into a first input branch 112A and a second input branch 112B. Additionally, the heat exchange system 100B includes a first output branch 116A and a second output branch 116B that merge into a common output conduit 114 or mix point.

[0022] The heat exchange system 100B, like the heat exchange system 100 A, includes a first upstream flow regulator 104 A and a second upstream flow regulator 104B. Similar to the heat exchange system 100A, the first upstream flow regulator 104A is fluidically coupled to the first input branch 112A and the second upstream flow regulator 104B is fluidically coupled to the second input branch 112B. However, unlike the heat exchange system 100 A, the heat exchange system 100B does not include downstream flow regulators. More specifically, the first output branch 116A and the second output branch 116B are not fluidically coupled with downstream flow regulators. Additionally, the common output conduit 114 does not have a downstream flow regulator. Therefore, the heat exchange system 100B does not have any flow regulators dedicated to controlling the cooling capacity of the first evaporator 102 A and the second evaporator 102B. Accordingly, the heat exchange system 100B has a lower part count that the heat exchange system 100 A, and thus can facilitate a system with a less weight, less volumetric footprint, more reliability, and less recurring costs than the heat exchange system 100 A.

[0023] Instead of having downstream flow regulators, the heat exchange system 100B relies on the upstream flow regulators to control, via complex switching controls, both the cooling capacity of the first evaporator 102 A and the second evaporator 102B and the superheated characteristics of the fluid exiting the first evaporator 102A and the second evaporator 102B. More specifically, the first upstream flow regulator 104 A of the heat exchange system 100B is controlled, according to a complex switching scheme, to control the cooling capacity of the first evaporator 102 A, according to a cooling-capacity control mode, when controlling the cooling capacity is prioritized, and to control the superheated characteristics of the fluid exiting the first evaporator 102 A, according to a superheated-state control mode, when controlling the superheated state of the fluid is prioritized. The secondupstream flow regulator 104B is similarly operated, but in association with the second evaporator 102B. The switching between the cooling-capacity mode and the superheated- state control mode for a given upstream flow regulator, and thus changes between prioritizing cooling capacity or superheated characteristics control, is governed according to a complex algorithm that takes into account multiple factors. Although the complex algorithm may be sophisticated and can optimize the switching between control modes, inevitably, under certain conditions, efficient or optimized control of the cooling capacity of the evaporators is sacrificed for efficient or optimized control of the superheated characteristics of the fluid, and vice versa.

[0024] Referring to Figure 3, a preferred example of a heat exchange system 100C is shown. The heat exchange system 100C has some similarities with the heat exchange system 100A of Figure 1 and the heat exchange system 100B, with like numbers referring to like elements. For example, the heat exchange system 100C includes a first evaporator 102A and a second evaporator 102B fluidically coupled together in parallel. The heat exchange system 100C also includes a common input conduit 110 or splitter that is split or divided into a first input branch 112A and a second input branch 112B. Additionally, the heat exchange system 100C includes a first output branch 116A and a second output branch 116B that are merged into a common output conduit 114 or mix point.

[0025] Like the heat exchange system 100 A, the heat exchange system 100C of Figure 3 includes a first downstream flow regulator 106 A and a second downstream flow regulator 106B. The first downstream flow regulator 106A is fluidically coupled to (e.g., situated within) the first output branch 116A and operable to control the flow rate of fluid flowing through the first evaporator 102A, which directly controls the cooling capacity of the first evaporator 102A. Similarly, the second downstream flow regulator 106B is fluidically coupled to (e.g., situated within) the second output branch 116B and operable to control the flow rate of fluid flowing through the second evaporator 102B, which directly controls the cooling capacity of the second evaporator 102B.

[0026] Because each one of the first downstream flow regulator 106 A and the second downstream flow regulator 106B has a dedicated cooling control mode, the downstream flow regulators of the heat exchange system 100C do not require switching between modes. Accordingly, this configuration results in simpler and more stable cooling control, which in turn promotes a more efficient vapor-compression cycle.

[0027] The heat exchange system 100C, like the heat exchange system 100 A and the heat exchange system 100B, includes an upstream flow regulator 104C. However, unlike theprevious heat exchange systems, the heat exchange system 100C includes only one upstream flow regulator 104C, as opposed to at least two as with the previous heat exchange systems. Moreover, unlike the upstream flow regulators of the heat exchange system 100 A and the heat exchange system 100B, which are situated within the first input branch 112A and the second input branch 112B downstream of the common input conduit 110, the single upstream flow regulator 104C of the heat exchange system 100C is fluidically coupled to (e.g., situated within) the common input conduit 110 upstream of the first input branch 112A and the second input branch 112B. Because the single upstream flow regulator 104C is upstream of the first input branch 112A and the second input branch 112B, the single upstream flow regulator 104C is operable to control the state of the fluid entering both the first input branch 112A and the second input branch 112B, and thus control the superheated state of fluid exiting both the first evaporator 102 A and the second evaporator 102B.

[0028] Although the superheat control of fluid exiting the first evaporator 102 A and the second evaporator 102B is shared via operation of a single upstream flow regulator 104C, unlike the upstream flow regulators of the heat exchange system 100B, the single upstream flow regulator 104C operates under a single dedicated control mode (i.e., the coolingcapacity control mode). Therefore, operation of the single upstream flow regulator 104C does not require complex switching between control modes. For this reason, the heat exchange system 100C can optimize control of the cooling capacity of the evaporators and the superheated characteristics of the fluid without sacrificing one for the other. In this manner, the heat exchange system 100C provides a system that has both a relatively low part count and the ability to concurrently optimize both cooling capacity and superheat control, without sacrificing one for the other.

[0029] Referring again to Figure 3, the heat exchange system 100C promotes scalability because additional evaporators can be added without adding any additional upstream flow regulators 104C. In other words, the single upstream flow regulator 104C can accommodate any number of evaporators, which enables easy and efficient expansion and cooling capacity of the heat exchange system 100C if desired. Accordingly, as shown, the heat exchange system 100C can add any quantity of evaporators 102N up to ‘N’ number of evaporators, as well as any number of input branches 112N up to ‘N’ number of input branches, without adding any additional upstream flow regulators. It is recognized that a downstream flow regulator 116N would be added for each additional evaporator 102N.

[0030] Referring to Figure 4, according to one example, the speed of the compressor 108 can be controlled according to the control system 200 to control (e.g., adjust) the flow rate offluid through a heat exchange system and thus the overall cooling capacity of the system. The control system 200 is configured to generate a compressor speed command 230 and operate the compressor 108 at the speed associated with the compressor speed command 230. Generally, the control system 200 is configured to conserve power and meet a required cooling capacity of the system by taking into account the downstream flow regulator that is most open and commanding the compressor 108 to operate at the lowest speed at which the compressor 108 can be run and still satisfy the required cooling capacity.

[0031] The control system 200 includes a maximum value module 204 that identifies the downstream flow regulator that is most open based on the valve positions 202 of the downstream flow regulator. The control system 200 then determines a difference between the position of the valve of the downstream flow regulator that is most open and a predetermined maximum valve position 206 of the downstream flow regulators. The difference is associated with an error that is provided to a compressor control module 228 of the control system 200 as an input. The compressor control module 228 also receives as input a predetermined minimum speed 224 at which the compressor 108 can operate and still circulate fluid through the heat exchange system. Additionally, the compressor control module 228 receives as input the current compressor speed 216 and an adjusted maximum compressor speed at which the compressor 108 can operate under current conditions. Based on one or more of at least these inputs, the compressor control module 228 determines a desired compressor speed and generates a compressor speed command 230 corresponding with the desired compressor speed.

[0032] The adjusted maximum compressor speed is the lowest of a maximum compressor speed 220 at which the compressor 108 can operate under any conditions and a maximum allowed compressor speed determined by a max speed module 218 of the control system 200. The control system 200 includes a minimum value module 222 that determines the lowest of the maximum compressor speed 220 and the maximum allowed compressor speed and sets the adjusted maximum compressor speed inputted to the compressor control module 228 accordingly. The max speed module 218 is configured to calculate the maximum allowed compressor speed based on several factors, including, but not limited to, a power input 208, a power budget 210, maximum fluid pressure 212, maximum fluid temperature 214, and / or the current compressor speed 216. The power input 208 is the current electrical power being consumed to operate into the heat exchange system. The power budget 210 is the maximum allowed electrical power consumption of the heat exchange system at any given time. The maximum fluid pressure 212 is the maximum pressure of the fluid flowing through the heatexchange system at any one or more locations within the system. The maximum fluid temperature 214 is the maximum temperature of the fluid flowing through the heat exchange system at any one or more locations within the system. When determining the compressor speed command 230, the compressor control module 228 is configured to select a compressor speed that is more than the minimum speed, no more than the adjusted maximum compressor speed, and is adjusted up or down in an attempt to reduce the error to zero.

[0033] In view of the foregoing, the present disclosure includes an improved heat exchange system, and associated architecture and control methods, for use in a variety of applications, including aerospace systems. In some examples, the improved heat exchange system is used in an environmental control system (ECS), which can include occupant cooling / heating, avionics cooling, auxiliary electronics cooling, auxiliary equipment cooling such as pods, engine oil cooling, transmission oil cooling, and auxiliary power unit cooling sub-systems. The heat exchange system disclosed herein can be of any size and shape. The evaporators and / or condenser of the heat exchange systems of the present disclosure may be operated as or configured to be a cross-flow device, a parallel-flow device, or a counter-flow device. The evaporators and / or the condenser disclosed herein can have an array of thousands of microtubes to convey fluid, if not more. The array of microtubes can be coupled together to act as one structure or one component of a larger structure, such as an aircraft system.

[0034] As used herein, the term "liquid" is defined as a fluid in liquid form. It is also recognized that a fluid, as used herein, can include any of various fluids, other than liquids, such as gases or plasmas.

[0035] In the above description, certain terms may be used such as "up," "down," "upper," "lower," "horizontal," "vertical," "left," "right," "over," "under" and the like. These terms are used, where applicable, to provide some clarity of description when dealing with relative relationships. But, these terms are not intended to imply absolute relationships, positions, and / or orientations. For example, with respect to an object, an "upper" surface can become a "lower" surface simply by turning the object over. Nevertheless, it is still the same object. Further, the terms "including," "comprising," "having," and variations thereof mean "including but not limited to" unless expressly specified otherwise. An enumerated listing of items does not imply that any or all the items are mutually exclusive and / or mutually inclusive, unless expressly specified otherwise. The terms "a," "an," and "the" also refer to "one or more" unless expressly specified otherwise. Further, the term "plurality" can be defined as "at least two." Moreover, unless otherwise noted, as defined herein a plurality ofparticular features does not necessarily mean every particular feature of an entire set or class of the particular features.

[0036] The term "about" or "substantially" or "approximately" in some embodiments, is defined to mean within + / -5% of a given value, however in additional embodiments any disclosure of "about" or "substantially" or "approximately" may be further narrowed and claimed to mean within + / - 4% of a given value, within + / - 3% of a given value, within + / - 2% of a given value, within + / - 1% of a given value, or the exact given value. Further, when at least two values of a variable are disclosed, such disclosure is specifically intended to include the range between the two values regardless of whether they are disclosed with respect to separate embodiments or examples, and specifically intended to include the range of at least the smaller of the two values and / or no more than the larger of the two values. Additionally, when at least three values of a variable are disclosed, such disclosure is specifically intended to include the range between any two of the values regardless of whether they are disclosed with respect to separate embodiments or examples, and specifically intended to include the range of at least the A value and / or no more than the B value, where A may be any of the disclosed values other than the largest disclosed value, and B may be any of the disclosed values other than the smallest disclosed value.

[0037] Additionally, instances in this specification where one element is "coupled" to another element can include direct and indirect coupling. Direct coupling can be defined as one element coupled to and in some contact with another element. Indirect coupling can be defined as coupling between two elements not in direct contact with each other, but having one or more additional elements between the coupled elements. Further, as used herein, securing one element to another element can include direct securing and indirect securing. Additionally, as used herein, "adjacent" does not necessarily denote contact. For example, one element can be adjacent to another element without being in contact with that element.

[0038] As used herein, the phrase "at least one of', when used with a list of items, means different combinations of one or more of the listed items may be used and only one of the items in the list may be needed. The item may be a particular object, thing, or category. In other words, "at least one of means any combination of items or number of items may be used from the list, but not all the items in the list may be required. For example, "at least one of item A, item B, and item C" may mean item A; item A and item B; item B; item A, item B, and item C; or item B and item C. In some cases, "at least one of item A, item B, and item C" may mean, for example, without limitation, two of item A, one of item B, and ten of item C; four of item B and seven of item C; or some other suitable combination.

[0039] Unless otherwise indicated, the terms "first," "second," etc. are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the items to which these terms refer. Moreover, reference to, e.g., a "second" item does not require or preclude the existence of, e.g., a "first" or lower-numbered item, and / or, e.g., a "third" or higher-numbered item.

[0040] As used herein, a system, apparatus, structure, article, element, component, or hardware "configured to" perform a specified function is indeed capable of performing the specified function without any alteration, rather than merely having potential to perform the specified function after further modification. In other words, the system, apparatus, structure, article, element, component, or hardware "configured to" perform a specified function is specifically selected, created, implemented, utilized, programmed, and / or designed for the purpose of performing the specified function. As used herein, "configured to" denotes existing characteristics of a system, apparatus, structure, article, element, component, or hardware which enable the system, apparatus, structure, article, element, component, or hardware to perform the specified function without further modification. For purposes of this disclosure, a system, apparatus, structure, article, element, component, or hardware described as being "configured to" perform a particular function may additionally or alternatively be described as being "adapted to" and / or as being "operative to" perform that function.

[0041] The schematic flow chart diagram(s), if included herein, is generally set forth as a logical flow chart diagram. As such, the depicted order and labeled steps are indicative of one example of the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.

[0042] Many of the functional units described in this specification have been labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or otherdiscrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.

[0043] Modules may also be implemented in code and / or software for execution by various types of processors. An identified module of code may, for instance, comprise one or more physical or logical blocks of executable code which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module.

[0044] Indeed, a module of code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different computer readable storage devices. Where a module or portions of a module are implemented in software, the software portions are stored on one or more computer readable storage devices.

[0045] Any combination of one or more computer readable medium may be utilized. The computer readable medium may be a computer readable storage medium. The computer readable storage medium may be a storage device storing the code. The storage device may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

[0046] More specific examples (a non-exhaustive list) of the storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0047] Code for carrying out operations for examples may be written in any combination of one or more programming languages including an object oriented programming languagesuch as Python, Ruby, Java, Smalltalk, C++, or the like, and conventional procedural programming languages, such as the "C" programming language, or the like, and / or machine languages such as assembly languages. The code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0048] The described features, structures, or characteristics of the examples may be combined in any suitable manner. In the above description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of examples. One skilled in the relevant art will recognize, however, that examples may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of an example.

[0049] Aspects of the examples are described above with reference to schematic flowchart diagrams and / or schematic block diagrams of methods, apparatuses, systems, and program products according to examples. It will be understood that each block of the schematic flowchart diagrams and / or schematic block diagrams, and combinations of blocks in the schematic flowchart diagrams and / or schematic block diagrams, can be implemented by code. These code may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions / acts specified in the schematic flowchart diagrams and / or schematic block diagrams block or blocks.

[0050] The code may also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions which implement the function / act specified in the schematic flowchart diagrams and / or schematic block diagrams block or blocks.

[0051] The code may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the code which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0052] The schematic flowchart diagrams and / or schematic block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods and program products according to various examples. In this regard, each block in the schematic flowchart diagrams and / or schematic block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions of the code for implementing the specified logical function(s).

[0053] The present subject matter may be embodied in other specific forms without departing from its spirit or essential characteristics. The described examples are to be considered in all respects only as illustrative and not restrictive. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

[0054] Further aspects are provided by the subject matter of the following clauses:

[0055] A heat exchange system (100C), comprising: a condenser; a first evaporator (102 A) fluidically coupled to the condenser to receive a refrigerant from the condenser; a second evaporator (102B) fluidically coupled to the condenser to receive the refrigerant from the condenser, and the second evaporator (102B) arranged in parallel with the first evaporator (102A); a compressor (108) fluidically coupled with the first evaporator (102A) and the second evaporator (102B), wherein the compressor (108) is configured to receive a fluid supplied from the first evaporator (102A) and the second evaporator (102B); a common input conduit (110) extending at least partially from the condenser to both of the first evaporator (102A) and the second evaporator (102B); an input flow regulator (104C) provided on the common input conduit (110); a first output flow regulator (106 A) provided between the first evaporator (102A) and the compressor (108); and a second output flow regulator (106B) provided between the second evaporator (102B) and the compressor (108).

[0056] The heat exchanger system (100C) of any preceding clause, further comprising a first output branch (116A) extending from the first evaporator (102A), and wherein the first output flow regulator (106A) is provided on the first output branch (116A).

[0057] The heat exchanger system (100C) of any preceding clause, further comprising a second output branch (116B) extending from the second evaporator (102B), and wherein the second output flow regulator (106B) is provided on the second output branch (116B).

[0058] The heat exchanger system (100C) of any preceding clause, further comprising a common output conduit (114) extending between the first output branch (116A), and the compressor (108) and between the second output branch (116B) and the compressor (108).

[0059] The heat exchanger system (100C) of any preceding clause, further comprising a first input branch (112A) extending between the common input conduit (110) and the first evaporator (102A), and a second input branch (112B) extending between the common input conduit (110) and the second evaporator (102B).

[0060] The heat exchanger system (100C) of any preceding clause, wherein the compressor (108) fluidly connects to the condenser to form a loop.

[0061] The heat exchanger system (100C) of any preceding clause, wherein the first evaporator (102 A) and the second evaporator (102B) are part of a set of at least three evaporators (102N) arranged in parallel between the condenser and the compressor (108).

[0062] The heat exchanger system (100C) of any preceding clause, wherein the first output flow regulator (106 A) and the second output flow regulator (106B) are part of a set of at least three output flow regulators (106N), with one output flow regulator of the set of at least three output flow regulators (106N) positioned between each evaporator of the at least three evaporators (102N) and the compressor (108).

[0063] The heat exchanger system (100C) of any preceding clause, wherein the first output flow regulator (106 A) and the second output flow regulator (106B) are configured to regulate superheated fluid to the compressor (108).

[0064] The heat exchanger system (100C) of any preceding clause, wherein the input flow regulator (104C) is configured to control a state of fluid provided to both the first evaporator (102 A) and the second evaporator (102B).

[0065] A method of exchanging heat between at least two environments, the method comprising: circulating a fluid to at least two evaporators (102N) arranged in parallel, wherein the at least two evaporators (102N) includes at least a first evaporator (102A) and a second evaporator (102B) arranged in parallel; controlling, with an input flow regulator, provision of the fluid from a condenser to the at least two evaporators (102N); controlling a first flow rate through the first evaporator (102 A) with a first output flow regulator; and controlling a second flow rate through the second evaporator (102B) with a second output flow regulator.

[0066] The method of any preceding clause, wherein the first output flow regulator (106A) controls a cooling capacity of the first evaporator (102A), and wherein the second output flow regulator (106B) controls the cooling capacity of the second evaporator (102B).

[0067] The method of any preceding clause, further comprising changing the fluid from a saturated or a subcooled liquid state to a liquid-vapor state with the input flow regulator (104C).

[0068] The method of any preceding clause, wherein controlling the first flow rate further comprises providing the fluid to a compressor (108) from the first evaporator (102A) with the first output flow regulator (106A), and wherein controlling the second flow rate further comprises providing the fluid to the compressor (108) from the second evaporator (102B) with the second output flow regulator (106B).

[0069] A method for controlling cooling capacity with a compressor (108) control module for a heat exchanger system including a compressor (108), a condenser, and at least two evaporators (102N) arranged in parallel between the condenser and the compressor (108), with a set of flow regulators (106N) having one flow regulator provided between each evaporator of the at least two evaporators (102N) and the compressor (108), the method comprising: identifying, with a maximum value module (204), a flow regulator of the set of flow regulators (106N) that is the most open; determining, with the compressor control module (200), a difference between a position of the flow regulator that is most open and a predetermined maximum valve position (206); determining, with the compressor control module (200), a current compressor speed (216); comparing the current compressor speed (216)with a maximum compressor speed (220); and generating a compressor speed command, based on at least one of the difference between the position of the flow regulator that is most open and the predetermined maximum valve position (206) or the comparison between the current compressor speed (216) and the maximum compressor speed (220), to operate a flow rate of fluid through the compressor (108) at a lowest speed at which the heat exchanger system can satisfy a required cooling capacity.

[0070] The method of any preceding clause, further comprising determining, with the compressor control module (200), a predetermined minimum speed (224) at which the heat exchanger system can still operate, and wherein the generated compressor speed command is at a speed that is greater than the predetermined minimum speed (224).

[0071] The method of any preceding clause, further comprising associating the difference between the position of the flow regulator that is most open and the predetermined maximum valve position (206) with an error.

[0072] The method of any preceding clause, further comprising adjusting the maximum compressor speed (220) to reduce the error toward zero.

[0073] The method of any preceding clause, wherein the maximum compressor speed (220) is an adjusted maximum compressor speed.

[0074] The method of any preceding clause, wherein the adjusted maximum compressor speed is based upon at least one of a power input (208), a power budget (210), a maximum fluid pressure (212), a maximum fluid temperature (214), or the current compressor speed (216).

Claims

CLAIMSWhat is claimed is:

1. A heat exchange system (100C), comprising: a condenser; a first evaporator (102A) fluidically coupled to the condenser to receive a refrigerant from the condenser; a second evaporator (102B) fluidically coupled to the condenser to receive the refrigerant from the condenser, and the second evaporator (102B) arranged in parallel with the first evaporator (102A); a compressor (108) fluidically coupled with the first evaporator (102A) and the second evaporator (102B), wherein the compressor (108) is configured to receive a fluid supplied from the first evaporator (102A) and the second evaporator (102B); a common input conduit (110) extending at least partially from the condenser to both of the first evaporator (102A) and the second evaporator (102B); an input flow regulator (104C) provided on the common input conduit (110); a first output flow regulator (106 A) provided between the first evaporator (102 A) and the compressor (108); and a second output flow regulator (106B) provided between the second evaporator (102B) and the compressor (108).

2. The heat exchanger system (100C) of claim 1, further comprising a first output branch (116A) extending from the first evaporator (102A), and wherein the first output flow regulator (106A) is provided on the first output branch (116A).

3. The heat exchanger system (100C) of claim 2, further comprising a second output branch (116B) extending from the second evaporator (102B), and wherein the second output flow regulator (106B) is provided on the second output branch (116B).

4. The heat exchanger system (100C) of claim 3, further comprising a common output conduit (114) extending between the first output branch (116A), and the compressor (108) and between the second output branch (116B) and the compressor (108).

5. The heat exchanger system (100C) of claim 4, further comprising a first input branch (112 A) extending between the common input conduit (110) and the first evaporator (102 A), and a second input branch (112B) extending between the common input conduit (110) and the second evaporator (102B).

6. The heat exchanger system (100C) of claim 1, wherein the compressor (108) fluidly connects to the condenser to form a loop.

7. The heat exchanger system (100C) of claim 1, wherein the first evaporator (102A) and the second evaporator (102B) are part of a set of at least three evaporators (102N) arranged in parallel between the condenser and the compressor (108).

8. The heat exchanger system (100C) of claim 7, wherein the first output flow regulator (106A) and the second output flow regulator (106B) are part of a set of at least three output flow regulators (106N), with one output flow regulator of the set of at least three output flow regulators (106N) positioned between each evaporator of the at least three evaporators (102N) and the compressor (108).

9. The heat exchanger system (100C) of claim 1, wherein the first output flow regulator (106A) and the second output flow regulator (106B) are configured to regulate superheated fluid to the compressor (108).

10. The heat exchanger system (100C) of claim 1, wherein the input flow regulator (104C) is configured to control a state of fluid provided to both the first evaporator (102A) and the second evaporator (102B).

11. A method of exchanging heat between at least two environments, the method comprising:circulating a fluid to at least two evaporators (102N) arranged in parallel, wherein the at least two evaporators (102N) includes at least a first evaporator (102A) and a second evaporator (102B) arranged in parallel; controlling, with an input flow regulator, provision of the fluid from a condenser to the at least two evaporators (102N); controlling a first flow rate through the first evaporator (102A) with a first output flow regulator; and controlling a second flow rate through the second evaporator (102B) with a second output flow regulator.

12. The method of claim 11, wherein the first output flow regulator (106A) controls a cooling capacity of the first evaporator (102A), and wherein the second output flow regulator (106B) controls the cooling capacity of the second evaporator (102B).

13. The method of claim 11, further comprising changing the fluid from a saturated or a subcooled liquid state to a liquid-vapor state with the input flow regulator (104C).

14. The method of claim 11, wherein controlling the first flow rate further comprises providing the fluid to a compressor (108) from the first evaporator (102 A) with the first output flow regulator (106 A), and wherein controlling the second flow rate further comprises providing the fluid to the compressor (108) from the second evaporator (102B) with the second output flow regulator (106B).

15. A method for controlling cooling capacity with a compressor (108) control module for a heat exchanger system including a compressor (108), a condenser, and at least two evaporators (102N) arranged in parallel between the condenser and the compressor (108), with a set of flow regulators (106N) having one flow regulator provided between each evaporator of the at least two evaporators (102N) and the compressor (108), the method comprising:identifying, with a maximum value module (204), a flow regulator of the set of flow regulators (106N) that is the most open; determining, with the compressor control module (200), a difference between a position of the flow regulator that is most open and a predetermined maximum valve position (206); determining, with the compressor control module (200), a current compressor speed (216); comparing the current compressor speed (216)with a maximum compressor speed (220); and generating a compressor speed command, based on at least one of the difference between the position of the flow regulator that is most open and the predetermined maximum valve position (206) or the comparison between the current compressor speed (216) and the maximum compressor speed (220), to operate a flow rate of fluid through the compressor (108) at a lowest speed at which the heat exchanger system can satisfy a required cooling capacity.

16. The method of claim 15, further comprising determining, with the compressor control module (200), a predetermined minimum speed (224) at which the heat exchanger system can still operate, and wherein the generated compressor speed command is at a speed that is greater than the predetermined minimum speed (224).

17. The method of claim 15, further comprising associating the difference between the position of the flow regulator that is most open and the predetermined maximum valve position (206) with an error.

18. The method of claim 17, further comprising adjusting the maximum compressor speed (220) to reduce the error toward zero.

19. The method of claim 15, wherein the maximum compressor speed (220) is an adjusted maximum compressor speed.

20. The method of claim 19, wherein the adjusted maximum compressor speed is based upon at least one of a power input (208), a power budget (210), a maximum fluid pressure (212), a maximum fluid temperature (214), or the current compressor speed (216).

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