Low-charge chiller and free cooling

Abstract

The system includes a vapor compression assembly and a free cooling assembly. The free cooling assembly corresponds to a cooling fluid and includes an air-cooled heat exchanger, an additional heat exchanger, and a valve. The system also includes a controller configured to receive data indicative of the ambient conditions, operating conditions, or both of the system. The controller is also configured to, based on the data, operate the valve between a first setting in which the cooling fluid is directed to the additional heat exchanger and blocked from the condenser of the vapor compression assembly, a second setting in which the cooling fluid is directed to the condenser and blocked from the additional heat exchanger, and a third setting in which a first portion of the cooling fluid is directed to the additional heat exchanger and a second portion of the cooling fluid is directed to the condenser.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority and the benefit thereof from U.S. Provisional Application No. 63 / 350,743, filed on June 9, 2022, entitled "LOW CHARGE CHILLER AND FREE COOLING", which is hereby incorporated by reference in its entirety for all purposes.

Background Art

[0002] This section is intended to introduce the reader to various aspects of the technology that may be relevant to the various aspects of the present disclosure described below. This discussion is thought to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, these descriptions should be read from this perspective and should not be read as an approval of the prior art.

[0003] This application generally relates to heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) systems that employ a vapor compression assembly (or "chiller assembly") and a free cooling assembly.

[0004] Certain HVAC&R systems, such as chillers, employ a vapor compression assembly. The vapor compression system utilizes a working fluid (e.g., refrigerant) that changes phase between vapor, liquid, and mixtures thereof in response to being exposed to different temperatures and pressures within the components of the vapor compression assembly. The vapor compression assembly may include an evaporator configured such that the working fluid is placed in a heat exchange relationship with, for example, a conditioning or process fluid (e.g., water) so that the working fluid absorbs heat from the process fluid. The process fluid cooled by the working fluid can then be directed towards a conditioned environment, such as a data center provided with information by the HVAC&R system. The process fluid can pass through downstream equipment, such as an air handler, to condition other fluids, such as air directed towards the conditioned environment. The condenser of the vapor compression assembly can receive the working fluid and be employed to condense the working fluid into the liquid phase. The compressor of the vapor compression assembly can be employed to urge the working fluid through the vapor compression assembly (e.g., by increasing the pressure of the working fluid).

[0005] In certain HVAC&R systems that employ a vapor compression assembly, a free cooling assembly may also be employed. For example, a cooling fluid (e.g., water, glycol, or a mixture thereof) associated with the free cooling assembly can be employed to cool various fluids associated with the HVAC&R system, such as the working fluid within the condenser of the vapor compression assembly. Further, a cooling tower (or other cooling source) can be employed in the free cooling assembly to reduce the temperature of the process fluid via ambient air. In this way, the free cooling assembly can utilize relatively low ambient air temperatures to provide cooling and reduce the load on the vapor compression assembly.

[0006] In conventional systems, the operation of the free cooling assembly can be actuated during specific conditions, such as when the ambient air temperature is relatively low. When the ambient air temperature is relatively low, the HVAC&R system can operate with appropriate cooling capacity without supplying power to the compressor (e.g., by relying on a heat siphon or natural convection for the movement of the working fluid) through the free cooling assembly and / or while reducing the dependence on the compressor (or other components) of the vapor compression assembly. However, in conventional HVAC&R systems that utilize vapor compression and free cooling assemblies, technical constraints may require that the dependence on the vapor compression assembly takes precedence over the dependence on the free cooling assembly. That is, in conventional HVAC&R systems, cooling can be highly dependent on the vapor compression assembly, which requires a relatively large refrigerant charge in the vapor compression assembly and contributes to the energy inefficiency of the HVAC&R system. Therefore, it is recognized here that an improved HVAC&R system employing vapor compression and free cooling assemblies is desired.

SUMMARY OF THE INVENTION

MEANS FOR SOLVING THE PROBLEM

[0007] The summary of specific embodiments disclosed herein is described below. It should be understood that these aspects are presented only to provide the reader with a brief overview of these specific embodiments and are not intended to limit the scope of the present disclosure. In fact, the present disclosure may encompass various aspects that may not be described below.

[0008] In one embodiment, the HVAC&R system includes a vapor compression assembly and a free cooling assembly. The free cooling assembly corresponds to a cooling fluid (e.g., within an internal fluid cooling loop) and includes an air-cooled heat exchanger, one or more additional heat exchangers, a fluid pump, and valves. The HVAC&R system also includes at least one controller configured to receive data indicative of the ambient conditions, operating conditions, or both, of the HVAC&R system. The at least one controller is also configured to actuate the valves among various settings based on the data. The various settings include a first setting in which the cooling fluid is directed to the additional heat exchanger and blocked from the condenser of the vapor compression assembly, a second setting in which the cooling fluid is directed to the condenser and blocked from the additional heat exchanger, and a third setting in which a first portion of the cooling fluid is directed to the additional heat exchanger and a second portion of the cooling fluid is directed to the condenser.

[0009] In another embodiment, a control assembly for a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system includes a sensor configured to detect the ambient or operating conditions of the HVAC&R system and at least one controller. The at least one controller is configured to receive feedback indicative of the ambient or operating conditions from the sensor. The at least one controller is also configured to actuate a valve of the free cooling assembly among various settings based on the feedback. The various settings include a first setting in which the cooling fluid of the free cooling assembly is directed to the heat exchanger of the free cooling assembly rather than the vapor compression assembly, a second setting in which the cooling fluid is directed to the vapor compression assembly rather than the heat exchanger, and at least one third setting in which a first portion of the cooling fluid is directed to the heat exchanger and a second portion of the cooling fluid is directed to the vapor compression assembly.

[0010] In yet another embodiment, a method of operating a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system includes receiving, via at least one controller, first data indicative of a first value of an ambient or operating condition of the HVAC&R system, and controlling a valve to a first setting based on the first data and via at least one controller such that a cooling fluid of a free cooling assembly is directed toward a heat exchanger of the free cooling assembly rather than a condenser of a vapor compression assembly. The method also includes receiving, via at least one controller, second data indicative of a second value of an ambient or operating condition of the HVAC&R system, the second value being different from the first value, and controlling the valve to a second setting based on the second data and via at least one controller such that the cooling fluid is directed toward the condenser rather than the heat exchanger. The method also includes receiving, via at least one controller, third data indicative of a third value of an ambient or operating condition of the HVAC&R system, the third value being different from the first value and the second value, and controlling the valve to a third setting based on the third data and via at least one controller such that a first portion of the cooling fluid is directed toward the heat exchanger and a second portion of the cooling fluid is directed toward the condenser.

[0011] Various aspects of the present disclosure may be better understood by reading the following detailed description and referring to the drawings.

Brief Description of the Drawings

[0012]

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DETAILED DESCRIPTION OF THE INVENTION

[0013] One or more specific embodiments are described below. To provide a concise description of these embodiments, not all features of an actual implementation are described herein. In the development of any such actual implementation, as in any engineering or design project, many implementation-specific decisions may need to be made that can vary from one implementation to another in order to achieve the developer's specific goals, such as compliance with system-related and industry-related constraints. Further, such development efforts can be complex and time-consuming, but it should be understood that for those skilled in the art who benefit from this disclosure, they are routine design, fabrication, and manufacturing tasks.

[0014] When introducing elements of various embodiments of the present disclosure, the articles "a," "an," and "the" are intended to mean that one or more of the elements are present. The terms "comprising," "including," and "having" are intended to be inclusive and mean that additional elements other than the listed elements may exist. Additionally, it should be understood that references to "one embodiment" or "an embodiment" of the present disclosure are not intended to be construed as excluding the existence of additional embodiments that also incorporate the recited features.

[0015] Embodiments of the present disclosure relate to heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) systems that utilize a vapor compression assembly and a free cooling assembly. The vapor compression assembly can be employed, for example, in the context of a chiller that is utilized to cool a conditioning or process fluid during certain conditions. Generally, an HVAC&R system is configured to cool a process fluid and route the process fluid towards a load. For example, the process fluid can be cooled by the HVAC&R system and directed to downstream equipment such as an air handling unit (AHU). The AHU can cool an air stream via the process fluid and distribute the air stream to various spaces (e.g., rooms, data centers) conditioned by the HVAC&R system. Alternatively, the process fluid can be employed to directly cool a load, such as equipment in a data center, in a liquid immersion application.

[0016] The vapor compression assembly can include a vapor compression loop (referred to as a working fluid loop in a particular example of the present disclosure) that circulates a working fluid (e.g., a refrigerant) through an evaporator, a condenser, and a compressor. The compressor can operate to compress the working fluid at a particular condition (e.g., increase its pressure), thereby driving the working fluid through the vapor compression loop. The evaporator can be employed to cool the process fluid by absorbing heat from the process fluid into the working fluid at a particular condition. The condenser can be employed to remove heat from the working fluid, for example, via a cooling fluid of an internal fluid cooling loop associated with the free cooling assembly at a particular condition. In this manner, the condenser can be considered a part of the internal fluid cooling loop while the cooling fluid of the internal fluid cooling loop is present in the condenser.

[0017] The free cooling assembly may include an air-cooled heat exchanger disposed in an external environment, a valve, and a plate-frame heat exchanger that provides liquid-liquid cooling. For example, the plate-frame heat exchanger may be employed to cool a process fluid via a cooling fluid of the free cooling assembly in certain conditions. The air-cooled heat exchanger, which may include a single fan (e.g., a single fan serving for a V-shaped coil assembly), may be employed to reduce the temperature of the cooling fluid before the cooling fluid is directed towards the plate-frame heat exchanger and / or the condenser of the vapor compression assembly.

[0018] The valve of the free cooling assembly (e.g., a diverter valve) may be disposed in an internal fluid cooling loop associated with the free cooling assembly. Further, the valve may be controlled to various valve settings that direct portions of the cooling fluid to the condenser, the plate-frame heat exchanger, or both. For example, in certain conditions, the valve may be controlled to a valve setting that directs the cooling fluid to the condenser and blocks the cooling fluid from the plate-frame heat exchanger. In certain other conditions, the valve may be controlled to a valve setting that directs the cooling fluid to the plate-frame heat exchanger and blocks the cooling fluid from the condenser. In certain other conditions, the valve may be controlled to a valve setting that directs a portion of the cooling fluid to the plate-frame heat exchanger and directs an additional portion of the cooling fluid to the condenser. According to the present disclosure, the controller may receive various inputs indicative of ambient conditions (e.g., ambient temperature, which is referred to as ambient dry bulb temperature in certain examples of the present disclosure) and / or operating conditions (e.g., return temperature of the process fluid from the load or target return temperature, supply temperature of the process fluid to the load or target supply temperature, operating load, etc.) of the HVAC&R system. Based on one or more of these inputs, the controller may operate the valve to a preferred valve setting such that the cooling fluid is directed towards the appropriate components of the HVAC&R system, as described above and in detail below.

[0019] Note that there may be several valve settings to direct a portion of the cooling fluid to the plate-frame heat exchanger and an additional portion of the cooling fluid to the condenser. Additionally or alternatively, only one valve setting of the valve may exist to direct a portion of the cooling fluid to the plate-frame heat exchanger and an additional portion of the cooling fluid to the condenser, and the pump may be controlled to regulate the amount or flow rate of the portion and the additional portion of the cooling fluid based on various conditions. In this way, the amount or flow rate of the portion of the cooling fluid directed to the plate-frame heat exchanger and the additional amount or additional flow rate of the additional portion of the cooling fluid directed to the condenser can be controlled to provide adequate cooling to the cooling fluid (and subsequently the load) while minimizing dependence on the vapor compression assembly.

[0020] In addition to the above, the settings of the compressor of the vapor compression system, which operates to increase the pressure of the working fluid within the vapor compression loop, can be controlled by a controller to correspond to the valve settings, to correspond to the pump settings, and / or based on the ambient and / or operating conditions described above. Further in addition to the above, the fan of the air-cooled heat exchanger can be controlled in settings to provide adequate cooling to the cooling fluid of the free-cooling assembly. Other control modes are also possible and will be described in detail with reference to the drawings.

[0021] By adopting the features described above, the HVAC&R system can provide cooling to conditioned spaces such as data centers through a significant dependence on the free cooling assembly and a relatively low dependence on the vapor compression assembly, thereby improving energy efficiency and reducing the refrigerant charge of the vapor compression assembly compared to conventional embodiments while providing adequate cooling. As an example, in the case of an HVAC&R system with a design load capacity of 500 tons of refrigeration where the operating load is 100% of the system's design load capacity, at least when the ambient temperature is about 60 degrees Fahrenheit or less, a supply temperature of the process fluid of 70 degrees Fahrenheit can be enabled through a complete dependence on the free cooling assembly (e.g., with the compressor of the vapor compression assembly turned off). Further, when the operating load is reduced, a supply temperature of the process fluid of 70 degrees Fahrenheit can be enabled through a complete dependence on the free cooling assembly when the ambient temperature is substantially higher than 60 degrees Fahrenheit. As an example, when the operating load is 50% of the system's design load capacity, the HVAC&R system can provide adequate cooling through a complete dependence on the free cooling assembly (e.g., with the compressor of the vapor compression assembly turned off) when the ambient temperature is about 65 degrees Fahrenheit or less, as described above. Of course, at even higher ambient temperatures, the HVAC&R system can rely more heavily on the free cooling assembly to provide the process fluid at an appropriate temperature to cool the load. Other examples are provided with reference to the drawings.

[0022] Generally, the systems and methods of the present disclosure enable cooling with a greater dependence on free cooling and a reduced dependence on vapor compression compared to conventional embodiments. By doing so, the required refrigerant charge of the vapor compression assembly is reduced compared to conventional embodiments, and the energy efficiency of the HVAC&R system is improved compared to conventional embodiments. These and other features are described in detail below with reference to the drawings.

[0023] FIG. 1 is a schematic diagram of one embodiment of an HVAC&R system 10 that employs a vapor compression assembly 12 (or chiller assembly), a free cooling assembly 14, and a control mechanism configured to regulate the dependence on the vapor compression assembly 12 and the free cooling assembly 14. Generally, the vapor compression assembly 12 and the free cooling assembly 14 are configured to cool a process fluid 16 (e.g., water, glycol, water-glycol mixture, dielectric fluid in immersion applications, etc.) corresponding to a process fluid loop 18, and the process fluid 16 is urged through the process fluid loop 18 via a pump 19. As shown in the figure, the process fluid loop 18 can direct the process fluid 16 to a load 20 (e.g., a conditioning space and / or a data center) to cool the load 20. Depending on the ambient and / or operating conditions of the HVAC&R system 10, the dependence on the vapor compression assembly 12 and / or the dependence on the free cooling assembly 14 for cooling the process fluid 16 can be adjusted to ensure proper cooling and reduce the energy consumption of the HVAC&R system 10 compared to conventional embodiments. These and other features are described in detail below with reference to FIG. 1.

[0024] The vapor compression assembly 12 can include a vapor compression loop 22 (referred to in a particular example of the present disclosure as a working fluid loop), and the vapor compression loop 22 routes a working fluid 24 (e.g., a refrigerant such as R-123, R-514A, R-1224yd, R-1233zd, R-134a, R-1234ze, R-1234yf, R-1311, R-32, R-410A, or others) through various components of the vapor compression assembly 12. For example, the vapor compression loop 22 can route the working fluid 24 through a compressor 28, a condenser 26, an expansion valve 32, and an evaporator 30 of the vapor compression assembly 12. The compressor 28 can operate to urge the working fluid 24 through the vapor compression loop 22 (e.g., by increasing the pressure of the working fluid 24) in a particular state. The evaporator 30 can operate to cool the process fluid 16 of the process fluid loop 18 in a particular state. The expansion valve 32 can operate to reduce the pressure of the working fluid 22 between the condenser 26 and the evaporator 30. The condenser 26 can operate to remove heat from the working fluid 24 in a particular state through liquid-liquid cooling in which heat is transferred from the working fluid 24 to a cooling fluid 34 (e.g., water, glycol, a water-glycol mixture, etc.) corresponding to an internal fluid cooling loop 36 of the free cooling assembly 14. In this way, the condenser 26 can be considered a part of the internal fluid cooling loop 36 while the cooling fluid 34 of the internal fluid cooling loop 36 is present in the condenser 26.

[0025] As described previously, in certain ambient and / or operating conditions of the HVAC&R system 10, the free cooling assembly 14 may be employed to reduce the reliance on the vapor compression assembly 12 for cooling the process fluid 16 of the process fluid loop 18. For example, as the reliance on the free cooling assembly 14 increases in response to certain conditions, the reliance on the compressor 28 of the vapor compression assembly 12 may be reduced. In certain conditions, while the HVAC&R system 10 relies only on the free cooling assembly 14 to provide cooling to the process fluid 16, the compressor 28 may be completely disconnected or otherwise turned off. The movement of the working fluid 24 through the vapor compression loop 22 may continue even after the compressor 28 is disconnected or otherwise turned off via natural convection (e.g., via a heat siphon). Additionally or alternatively, the HVAC&R system 10 may rely on both the free cooling assembly 14 and the vapor compression assembly 12 in certain conditions where the compressor 28 is controlled to a relatively low setting, thereby improving energy efficiency while ensuring proper cooling of the process fluid 16. The aspects of the free cooling assembly 14, as well as the control of the HVAC&R system 10 for regulating the reliance on the vapor compression assembly 12 and / or the free cooling assembly 14, will be described in detail below.

[0026] In the illustrated embodiment, the free cooling assembly 14 includes an internal fluid cooling loop 36 configured to route a cooling fluid 34 through various components of the HVAC&R system 10, including a condenser 26 of the vapor compression assembly 12, an air-cooled heat exchanger 38 of the free cooling assembly 14 (e.g., having a fan 39), and a plate-frame heat exchanger 40 of the free cooling assembly 14. Generally, the air-cooled heat exchanger 38 is configured to cool the cooling fluid 34 (e.g., via the fan 39) before the cooling fluid 34 is delivered to the condenser 26 of the vapor compression assembly 12 and / or the plate-frame heat exchanger 40 of the free cooling assembly 14. In some embodiments, the air-cooled heat exchanger 38 may include only an example of the fan 39 configured to cool the cooling fluid 34 before the cooling fluid 34 is delivered to the condenser 26 and / or the plate-frame heat exchanger 40.

[0027] When the cooling fluid 34 is present in the condenser 26, the cooling fluid 34 absorbs heat from the working fluid 24 corresponding to the vapor compression assembly 12 and condenses the working fluid 24 before the working fluid 24 is delivered to the expansion valve 32. When the cooling fluid 34 is present in the plate-frame heat exchanger 40, the cooling fluid 34 absorbs heat from the process fluid 16 corresponding to the process fluid loop 18. Aspects of the free cooling assembly 14 can be controlled to allocate some, none, or all of the cooling fluid 34 to the condenser 26 and some, none, or all of the cooling fluid 34 to the plate-frame heat exchanger 40, as will be described in detail below.

[0028] The free cooling assembly 14 includes a valve 42 controlled in various settings for directing a portion of the cooling fluid 34 towards the condenser 26 of the vapor compression assembly 12 and / or the plate frame heat exchanger 40 of the free cooling assembly 14. Further, the free cooling assembly 14 includes a pump 44 configured to urge the cooling fluid 34 through the internal fluid cooling 36. Depending on the ambient and / or operating conditions of the HVAC&R system 10, the valve 42 can be controlled to a first valve setting where the cooling fluid 34 is directed towards the plate frame heat exchanger 40 and blocked from the condenser 26, a second valve setting where the cooling fluid 34 is directed towards the condenser 26 and blocked from the plate frame heat exchanger 40, or a third setting (or one of several third settings) where a portion of the cooling fluid 34 is directed towards the plate frame heat exchanger 40 and an additional portion of the cooling fluid 34 is directed towards the condenser 26.

[0029] A controller 46 of the HVAC&R system 10 can be employed to control the various components described above. In the illustrated embodiment, the controller 46 includes a processing circuit 48 and a memory circuit 50 having instructions stored thereon, and the instructions, when implemented by the processing circuit 48, cause the processing circuit 48 to perform various functions. Note that, for the sake of brevity, only one example of the controller 46 is shown in the illustrated embodiment. However, note that multiple controllers (including dedicated processing and / or memory circuits) can be employed to implement the control mechanisms described in the present disclosure.

[0030] Controller 46 may receive one or more inputs indicative of various ambient and / or operating conditions of HVAC&R system 10. For example, controller 46 may receive a first input from first sensor 52 indicative of ambient temperature (e.g., proximate to air-cooled heat exchanger 38). Additionally or alternatively, controller 46 may receive a second input from second sensor 54 indicative of the supply temperature of process fluid 16 directed to load 20. Additionally or alternatively, controller 46 may receive a third input from third sensor 56 indicative of the return temperature of process fluid 16 returned from load 20. In some embodiments, controller 46 may employ a target supply temperature of process fluid 16 directed to load 20, and / or a target return temperature of process fluid 16 returned from load 20 (e.g., in addition to, or instead of, the detected temperature). Additionally or alternatively, controller 46 may receive (or otherwise determine) a fourth input indicative of an operating load or cooling demand corresponding to HVAC&R system 10 and / or load 20. Indeed, HVAC&R system 10 may include the design load capacity of the system, but the cooling demand of load 20 at a particular operating interval may correspond to an operating load that is less than the design load capacity of the system. The fourth input indicative of operating load or cooling demand may be, for example, a certain percentage of the design load capacity of the system. The fourth input may be received from a sensor or other feedback device that may be part of (or separate from) one or more controllers 46. The control assembly may include one or more controllers 46 according to the present disclosure and, in some embodiments, may include any combination of first sensor 52, second sensor 54, third sensor 56, and / or other sensors or feedback devices.

[0031] In response to at least one of the inputs described above (e.g., ambient temperature, supply temperature and / or target supply temperature of process fluid 16, return temperature and / or target return temperature of process fluid 16, operating load), the controller 46 may control various components of the HVAC&R system 10 to ensure proper cooling of the load 20 while reducing energy consumption. Specifically, the controller 46 may control the valve 42 of the free cooling assembly 14 to direct some or all of the cooling fluid 34 to the condenser 26 of the vapor compression assembly 12 and to direct some or all of the cooling fluid 34 to the plate frame heat exchanger 40.

[0032] Other aspects of the HVAC&R system 10 may also be controlled to correspond to the valve setting of the valve 42 (or based on the inputs described above). For example, the settings of the compressor 28 and / or the fan 39 of the air-cooled heat exchanger 38 may be controlled in a manner that provides proper cooling to the process fluid 16 while reducing the energy consumption of the HVAC&R system 10. Generally, the systems and methods of the present disclosure are configured such that the HVAC&R system 10 is able to provide proper cooling to the process fluid 16 while relying heavily on the free cooling assembly 14, thereby improving the efficiency of the HVAC&R system 10 as compared to conventional embodiments.

[0033] Figures 2-7 illustrate various embodiments of the HVAC&R system 10 with different ambient temperatures and operating loads. As seen in Figures 2-7 and described in detail below, the control is adjusted based at least in part on the ambient temperature and the operating load. In Figures 2-4, the operating load is 100% of the design load capacity of the system (e.g., at ambient temperatures of 85 degrees Fahrenheit, 65 degrees Fahrenheit, and 60 degrees Fahrenheit, respectively). In Figures 5-7, the operating load is 50% of the design load capacity of the system (e.g., at ambient temperatures of 85 degrees Fahrenheit, 65 degrees Fahrenheit, and 60 degrees Fahrenheit, respectively). Generally, the lower the ambient temperature and / or the operating load, the more the HVAC&R system 10 relies on the free cooling assembly 14 for energy savings. Each of Figures 2-7 is described individually and in detail below.

[0034] Figure 2 is a schematic diagram of one embodiment of the HVAC&R system 10 of FIG. 1, and (as shown in legend 59, for example) the ambient temperature is 85 degrees Fahrenheit and the operating load is 100% of the design load capacity of the system. Further, the supply temperature of the process fluid 16 to the load 20 is 70 degrees Fahrenheit and the return temperature of the process fluid 16 from the load 20 is 100 degrees Fahrenheit. In the illustrated embodiment, the controller 46 of the HVAC&R system 10 controls the valve 42 of the free-cooling assembly 14 to a valve setting such that the cooling fluid 34 is directed toward the condenser 26 of the vapor compression assembly 12 and blocked from the plate-frame heat exchanger 40 of the free-cooling assembly 14. Thus, the HVAC&R system 10 depends on the vapor compression assembly 12 (e.g., the compressor 28 is on and controlled to a sufficient setting) to cool the process fluid 16 via the evaporator 30 and does not depend on the plate-frame heat exchanger 40. That is, none of the cooling fluid 34 is directed toward the plate-frame heat exchanger 40.

[0035] The illustrated control depends on the vapor compression assembly 12 as indicated by a relatively high ambient temperature (e.g., 85 degrees Fahrenheit) and operating load (e.g., 100% of the design load capacity of the system). In fact, as shown in the illustrated embodiment, the valve 42 is controlled to a valve setting such that the cooling fluid 34 routed to the condenser 26 is at about 93 degrees Fahrenheit at a flow rate of about 600 gallons per minute (GPM) and none of the cooling fluid 34 is routed to the plate-frame heat exchanger 40.

[0036] In addition to adjusting the valve setting of the valve 42 as described above, the controller 46 can also adjust the pump setting of the pump 44 associated with the internal fluid cooling loop 36 of the free cooling assembly 14, the compressor setting of the compressor 28 associated with the vapor compression loop 22 of the vapor compression assembly 12, the pump setting of the pump 19 associated with the process fluid loop 18, the fan setting of the fan 39 of the air-cooled heat exchanger 38, or any combination thereof. Various performance and result data are illustrated in FIG. 2 and are associated with the states described above, which states are associated with parameters related to the compressor 28, the condenser 26, the evaporator 30, the air-cooled heat exchanger 38 (or its fan 39), the plate-frame heat exchanger 40, the load 20, the valve 42, the pump 44, the pump 19, the temperatures of various fluids, the flow rates of various fluids, the power consumption of various components, etc. Further, as shown in block 60, the total chiller kilowatts per ton (kW / ton) for the illustrated state and control mechanism is 0.690.

[0037] FIG. 3 is a schematic diagram of an embodiment of the HVAC&R system 10 of FIG. 1, where the ambient temperature is 65 degrees Fahrenheit and the operating load is 100% of the system's design load capacity (as shown in legend 59, for example). Further, the supply temperature of the process fluid 16 to load 20 is 70 degrees Fahrenheit, and the return temperature of the process fluid 16 from load 20 is 100 degrees Fahrenheit. In the illustrated embodiment, the controller 46 of the HVAC&R system 10 controls the valve 42 of the free-cooling assembly 14 to direct the first portion of the cooling fluid 34 (e.g., at a first flow rate) toward the condenser 26 of the vapor-compression assembly 12 and the second portion of the free-cooling fluid 34 (e.g., at a second flow rate) toward the plate-frame heat exchanger 40 of the free-cooling assembly 14. Thus, the HVAC&R system 10 depends on the vapor-compression assembly 12 to cool the process fluid 16 via the evaporator 30 (e.g., with the compressor 28 on and controlled to a sufficient setting), and depends on the free-cooling assembly 14 to cool the process fluid 16 via the plate-frame heat exchanger 40.

[0038] The control illustrated depends on both the vapor compression assembly 12, (e.g., with the compressor 28 on and controlled to a sufficient setting), and the plate frame heat exchanger 40 of the free cooling assembly 14, as indicated by a relatively moderate temperature (e.g., 65 degrees Fahrenheit) and a high operating load (e.g., 100% of the design load capacity of the system). As shown in the illustrated embodiment, the valve 42 is controlled to a valve setting such that the portion of the cooling fluid 34 routed to the condenser 26 is at a flow rate of about 200 GPM and at about 67 degrees Fahrenheit, and the portion of the cooling fluid 34 routed to the plate frame heat exchanger 40 is at a flow rate of about 400 GPM and at about 67 degrees Fahrenheit. Of course, when the ambient temperature rises from 65 degrees Fahrenheit, the valve 42 and / or the pump 44 of the free cooling assembly 14 can be controlled such that the flow rate of the cooling fluid 34 directed towards the condenser 26 is greater than about 200 GPM, and the flow rate of the cooling fluid 34 directed towards the plate frame heat exchanger 40 is less than about 400 GPM. Additionally, when the ambient temperature drops from 65 degrees Fahrenheit, the valve 42 and / or the pump 44 of the free cooling assembly 14 can be controlled such that the flow rate of the cooling fluid 34 directed towards the condenser 26 is less than about 200 GPM, and the flow rate of the cooling fluid 34 directed towards the plate frame heat exchanger 40 is greater than about 400 GPM.

[0039] In addition to adjusting the valve settings of valve 42 as described above, the controller 46 may also adjust the pump settings of pump 44 associated with the internal fluid cooling loop 36 of the free cooling assembly 14, the compressor settings of compressor 28 associated with the vapor compression loop 22 of the vapor compression assembly 12, the pump settings of pump 19 associated with the process fluid loop 18, the fan settings of fan 39 of the air-cooled heat exchanger 38, or any combination thereof. Various performance and result data are illustrated in FIG. 3 and are associated with the states described above, which states are associated with parameters related to compressor 28, condenser 26, evaporator 30, air-cooled heat exchanger 38 (or its fan 39), plate-frame heat exchanger 40, load 20, valve 42, pump 44, pump 19, temperatures of various fluids, flow rates of various fluids, power consumption of various components, etc. Further, as shown in block 60, the total chiller kW / ton for the illustrated state and control mechanism is 0.089, which is substantially lower than that of the embodiment illustrated in FIG. 2.

[0040] FIG. 4 is a schematic diagram of an embodiment of the HVAC&R system 10 of FIG. 1, where (as shown, for example, in legend 59) the ambient temperature is 60 degrees Fahrenheit and the operating load is 100% of the system's design load capacity. Further, the supply temperature of the process fluid 16 to load 20 is 70 degrees Fahrenheit, and the return temperature of the process fluid 16 from load 20 is 100 degrees Fahrenheit. In the illustrated embodiment, the controller 46 of the HVAC&R system 10 controls the valve 42 of the internal fluid cooling loop 36 to a valve setting such that the cooling fluid 34 is blocked from the condenser 26 of the vapor compression assembly 12 and directed towards the plate frame heat exchanger 40 of the free cooling assembly 14. Thus, the HVAC&R system 10 relies on the plate frame heat exchanger 40 of the free cooling assembly 14 to cool the process fluid 16 of the process fluid loop 18 and does not rely on the evaporator 30 of the vapor compression assembly 12 to cool the process fluid 16 of the process fluid loop 18. The illustrated control relies on (and does not rely on the vapor compression assembly 12) the free cooling assembly 14 as shown for a relatively low ambient temperature (e.g., 60 degrees Fahrenheit) despite a high operating load (e.g., 100% of the system's design load capacity).

[0041] In addition to adjusting the valve setting of valve 42 as described above, the controller 46 may also adjust the pump setting of pump 44 associated with the internal fluid cooling loop 36 of the free cooling assembly 14, the compressor setting of compressor 28 associated with the vapor compression loop 22 of the vapor compression assembly 12, the pump setting of pump 19 associated with the process fluid loop 18, the fan setting of fan 39 of the air-cooled heat exchanger 38, or any combination thereof. Various performance and result data are illustrated in FIG. 4 and are associated with the states described above, which states are associated with parameters related to compressor 28, condenser 26, evaporator 30, air-cooled heat exchanger 38 (or its fan 39), plate-frame heat exchanger 40, load 20, valve 42, pump 44, pump 19, the temperatures of various fluids, the flow rates of various fluids, the power consumption of various components, etc. Further, as shown in block 60, the total chiller kW / ton for the illustrated state and control mechanism is 0.030, which is substantially lower than the embodiments illustrated in FIGS. 2 and 3.

[0042] FIG. 5 is a schematic diagram of an embodiment of the HVAC&R system 10 of FIG. 1, where (as shown in legend 59, for example) the ambient temperature is 85 degrees Fahrenheit and the operating load is 50% of the system's design load capacity. Further, the supply temperature of the process fluid 16 to load 20 is 70 degrees Fahrenheit and the return temperature of the process fluid 16 from load 20 is 100 degrees Fahrenheit. In the illustrated embodiment, the controller 46 of the HVAC&R system 10 controls the valve 42 of the free-cooling assembly 14 to direct a first portion of the cooling fluid 34 (e.g., at a first flow rate) toward the condenser 26 of the vapor-compression assembly 12 and to direct a second portion of the free-cooling fluid 34 (e.g., at a second flow rate) toward the plate-frame heat exchanger 40 of the free-cooling assembly 14. Thus, the HVAC&R system 10 relies on the vapor-compression assembly 12 to cool the process fluid 16 via the evaporator 30 (e.g., with the compressor 28 on and controlled to a sufficient setting), and the HVAC&R system 10 relies on the plate-frame heat exchanger 40 of the free-cooling assembly 14 to cool the process fluid 16.

[0043] The illustrated control depends on both the vapor compression assembly 12, (e.g., with the compressor 28 on and controlled to a sufficient setting), and the plate frame heat exchanger 40 of the free cooling assembly 14, as indicated by a relatively low operating load (e.g., 50% of the designed load capacity of the system), despite a relatively high ambient temperature (e.g., 85 degrees Fahrenheit). As shown in the illustrated embodiment, the valve 42 is controlled to a valve setting such that the portion of the cooling fluid 34 routed to the condenser 26 is at a flow rate of about 137 GPM and at about 89 degrees Fahrenheit, and the portion of the cooling fluid 34 routed to the plate frame heat exchanger 40 is at a flow rate of about 163 GPM and at about 89 degrees Fahrenheit. Of course, when the ambient temperature rises above 85 degrees Fahrenheit, the valve 42 and / or the pump 44 of the free cooling assembly 14 can be controlled such that the flow rate of the cooling fluid 34 directed towards the condenser 26 is greater than about 137 GPM, and the flow rate of the cooling fluid 34 directed towards the plate frame heat exchanger 40 is less than about 163 GPM. Additionally, when the ambient temperature drops below 85 degrees Fahrenheit, the valve 42 and / or the pump 44 of the free cooling assembly 14 can be controlled such that the flow rate of the cooling fluid 34 directed towards the condenser 26 is less than about 137 GPM, and the flow rate of the cooling fluid 34 directed towards the plate frame heat exchanger 40 is greater than about 163 GPM. Similar adjustments can be made based on changes in the operating load.

[0044] In addition to adjusting the valve settings of valve 42 as described above, controller 46 may also adjust the pump settings of pump 44 associated with the internal fluid cooling loop 36 of free cooling assembly 14, the compressor settings of compressor 28 associated with the vapor compression loop 22 of vapor compression assembly 12, the pump settings of pump 19 associated with process fluid loop 18, the fan settings of fan 39 of air-cooled heat exchanger 38, or any combination thereof. Various performance and result data are illustrated in FIG. 5 and are associated with the states described above, which states are associated with parameters related to compressor 28, condenser 26, evaporator 30, air-cooled heat exchanger 38 (or its fan 39), plate-frame heat exchanger 40, load 20, valve 42, pump 44, pump 19, the temperatures of various fluids, the flow rates of various fluids, the power consumption of various components, etc. Further, as shown in block 60, the total chiller kW / ton for the illustrated state and control mechanism is 0.380, which is substantially lower than that of the embodiment illustrated in FIG. 2. In fact, the ambient temperature is 85 degrees Fahrenheit in both FIGS. 2 and 5, but the operating load in FIG. 5, which is lower than that in FIG. 2, enables it to depend at least in part on free cooling assembly 14, thereby reducing the total chiller kW / ton.

[0045] FIG. 6 is a schematic diagram of an embodiment of the HVAC&R system 10 of FIG. 1, where (as shown in legend 59, for example) the ambient temperature is 65 degrees Fahrenheit and the operating load is 50% of the system's design load capacity. Further, the supply temperature of the process fluid 16 to the load 20 is 70 degrees Fahrenheit, and the return temperature of the process fluid 16 from the load 20 is 100 degrees Fahrenheit. In the illustrated embodiment, the controller 46 of the HVAC&R system 10 controls the valve 42 of the free-cooling assembly 14 to a valve setting such that the cooling fluid 34 is directed toward the plate-frame heat exchanger 40 of the free-cooling assembly 14 and blocked from the condenser 26 of the vapor-compression assembly 12. Thus, the HVAC&R system 10 depends on the plate-frame heat exchanger 40 of the free-cooling assembly 14 to cool the process fluid 16 of the process fluid loop 18 and does not depend on the evaporator 30 of the vapor-compression assembly 12 to cool the process fluid 16 of the process fluid loop 18. The illustrated control depends on the free-cooling assembly 14 (and does not depend on the vapor-compression assembly 12, which may include a compressor 28 that is disconnected or otherwise turned off) as shown for relatively moderate ambient temperatures (e.g., 65 degrees Fahrenheit) and relatively low operating loads (e.g., 50% of the system's design load capacity).

[0046] In addition to adjusting the valve setting of valve 42 as described above, the controller 46 may also adjust the pump setting of pump 44 associated with the internal fluid cooling loop 36 of the free cooling assembly 14, the compressor setting of compressor 28 associated with the vapor compression loop 22 of the vapor compression assembly 12, the pump setting of pump 19 associated with the process fluid loop 18, the fan setting of fan 39 of the air-cooled heat exchanger 38, or any combination thereof. Various performance and result data are illustrated in FIG. 6 and are associated with the states described above, which states are associated with parameters related to the compressor 28, condenser 26, evaporator 30, air-cooled heat exchanger 38 (or its fan 39), plate-frame heat exchanger 40, load 20, valve 42, pump 44, pump 19, temperatures of various fluids, flow rates of various fluids, power consumption of various components, etc. Further, as shown in block 60, the total chiller kW / ton for the illustrated states and control mechanisms is 0.008, which is substantially lower than the kW / ton in FIGS. 2-5.

[0047] FIG. 7 is a schematic diagram of an embodiment of the HVAC&R system 10 of FIG. 1, where (as shown, for example, in legend 59) the ambient temperature is 60 degrees Fahrenheit and the operating load is 50% of the system's design load capacity. Further, the supply temperature of the process fluid 16 to load 20 is 70 degrees Fahrenheit and the return temperature of the process fluid 16 from load 20 is 100 degrees Fahrenheit. As described above with respect to FIG. 6, in the embodiment illustrated in FIG. 7, the controller 46 of the HVAC&R system 10 controls the valve 42 of the internal fluid cooling loop 36 to a valve setting such that the cooling fluid 34 is directed towards the plate-frame heat exchanger 40 of the free-cooling assembly 14 and blocked from the condenser 26 of the vapor-compression assembly 12. Thus, the HVAC&R system 10 depends on the plate-frame heat exchanger 40 of the free-cooling assembly 14 to cool the process fluid 16 of the process fluid loop 18 and does not depend on the evaporator 30 of the vapor-compression assembly 12 to cool the process fluid 16 of the process fluid loop 18. The illustrated control depends on the free-cooling assembly 14 (and does not depend on the vapor-compression assembly 12, including the compressor 28 which is disconnected or otherwise turned off) as shown for relatively low ambient temperatures (e.g., 60 degrees Fahrenheit) and operating loads (e.g., 50% of the system's design load capacity).

[0048] In addition to adjusting the valve setting of valve 42 as described above, the controller 46 may also adjust the pump setting of pump 44 associated with the internal fluid cooling loop 36 of the free cooling assembly 14, the compressor setting of compressor 28 associated with the vapor compression loop 22 of the vapor compression assembly 12, the pump setting of pump 19 associated with the process fluid loop 18, the fan setting of fan 39 of the air-cooled heat exchanger 38, or any combination thereof. Various performance and result data are illustrated in FIG. 7 and are associated with the states described above, which states are associated with parameters related to compressor 28, condenser 26, evaporator 30, air-cooled heat exchanger 38 (or its fan 39), plate-frame heat exchanger 40, load 20, valve 42, pump 44, pump 19, temperatures of various fluids, flow rates of various fluids, power consumption of various components, etc. Further, as shown in block 60, the total chiller kW / ton for the illustrated states and control mechanisms is 0.005.

[0049] In both FIGS. 6 and 7, it should be noted that the valve 42 is controlled (e.g., via the controller 46) to a setting that blocks the cooling fluid 34 from the condenser 26 of the vapor compression assembly 12 and directs the cooling fluid 24 to the plate frame heat exchanger 40 of the free cooling assembly 14. Despite such a correspondence in the flow of the cooling fluid 34 in FIGS. 6 and 7, the total chiller kW / ton in FIG. 7 is lower than that in FIG. 6. The lower total chiller kW / ton in FIG. 7 compared to that in FIG. 6 is based on the lower ambient temperature (e.g., 60 degrees in FIG. 7 and 65 degrees in FIG. 6) and the corresponding control of other features of the HVAC&R system 10. In fact, due to the reduced ambient temperature, other components of the HVAC&R system 10, such as the fan 39 of the air-cooled heat exchanger 38, can be operated in a manner that reduces energy consumption. For example, the fan 39 of the air-cooled heat exchanger 38 in FIG. 6 operates at 1.4 kW, while the fan 39 of the air-cooled heat exchanger 38 in FIG. 7 operates at 0.7 kW. In this way, the fan 39 can be a variable speed fan that is controlled to a setting based on, for example, the desired or target cooling amount of the cooling fluid 34 by the fan 39.

[0050] Generally, the HVAC&R system 10 according to the present disclosure is configured to rely more on the free cooling assembly 14 than on the vapor compression assembly 12 compared to conventional embodiments, regardless of whether the HVAC&R system 10 is operated to rely only on the vapor compression assembly 12 to cool the process fluid 16, to rely only on the free cooling assembly 14 to cool the process fluid 16, or to rely on both the vapor compression assembly 12 and the free cooling assembly 14 to cool the process fluid 16.

[0051] FIG. 8 is a process flow diagram illustrating an embodiment of a method 100 for operating the HVAC&R system of FIG. 1. In the illustrated embodiment, method 100 includes urging a process fluid through a process fluid loop via a pump such that the process fluid is routed through an evaporator of a vapor compression assembly, a load, and a plate frame heat exchanger of a free cooling assembly (block 102). Depending on the ambient conditions, operating conditions, and / or certain corresponding control mechanisms of the HVAC&R system, the working fluid of the vapor compression assembly, the cooling fluid of the free cooling assembly, or both may be employed to cool the process fluid. For example, the evaporator of the vapor compression assembly may be employed to cool the process fluid via the working fluid of the vapor compression assembly in certain conditions. Additionally or alternatively, the plate frame heat exchanger may be employed to cool the process fluid via the cooling fluid of the free cooling assembly in certain conditions.

[0052] Method 100 also includes detecting an ambient temperature via a sensor (e.g., a temperature sensor) (block 104). The sensor may be disposed, for example, adjacent to an air-cooled heat exchanger of the free cooling assembly. As will be appreciated in view of the following description, the ambient temperature detected by the sensor is utilized to determine various control mechanisms associated with the HVAC&R system, such as a control mechanism employed to route the cooling fluid of the free cooling assembly to a condenser of the vapor compression assembly (e.g., to remove heat from the working fluid of the vapor compression assembly), a plate frame heat exchanger of the free cooling assembly (e.g., to cool the process fluid), or both.

[0053] Method 100 also includes controlling the valve settings of the valves of the free cooling assembly (block 106) to control one or more flows of the cooling fluid of the free cooling assembly to the condenser of the vapor compression assembly, the plate frame heat exchanger of the free cooling assembly, or both, via the controller and based at least on the ambient temperature and the operating load (or cooling demand) associated with the load. Various control mechanisms associated with various ambient temperatures and / or operating loads are illustrated in FIGS. 2-7 and described in detail above. Generally, when the ambient temperature and / or operating load is relatively low, the system relies more (or completely) on the free cooling assembly than on the vapor compression assembly. The valve settings of the valves may also depend at least in part on the supply temperature (or target supply temperature) of the process fluid to the load and / or the return temperature (or target return temperature) of the process fluid from the load.

[0054] Method 100 also includes controlling other aspects of the HVAC&R system (block 108) via a controller. For example, the control of other aspects of the HVAC&R system may depend at least in part on the ambient and / or operating conditions described above for the HVAC&R system. Additionally or alternatively, the control of other aspects of the HVAC&R system may depend on the valve settings of the valves. Aspects of the HVAC&R system that may be controlled according to the data mentioned above include the compressor settings of the compressor, the pump settings of the pumps corresponding to the free cooling assembly, the pump settings of the pumps corresponding to the process fluid loop, the fan settings of the air-cooled heat exchanger of the free cooling assembly, and / or other aspects of the HVAC&R system. For example, if the system relies only on the free cooling assembly to cool the process fluid, the compressor may be disconnected, turned off, or otherwise controlled to a reduced setting. Additionally or alternatively, if the system includes a relatively low dependence on the vapor compression assembly to cool the process fluid, the compressor settings may be reduced. Further, the fan settings of the fans of the air-cooled heat exchanger may be reduced if the ambient temperature and / or operating load is relatively low. Based on these controls, the control of the valve settings, and other aspects of the HVAC&R system of the present disclosure, sufficient cooling to the process fluid (and subsequently the load) can be provided while reducing energy consumption and reducing the refrigerant charge in the vapor compression assembly as compared to conventional embodiments.

[0055] Illustrated in FIGS. 1 - 7, the features described above with respect to FIGS. 1 - 7 are examples of an HVAC&R system that employs a vapor compression assembly and a free cooling assembly, and the free cooling assembly is preferred for energy savings and reduced refrigerant charge in the vapor compression assembly. The components illustrated in FIGS. 1 - 7 and described in detail above may enable energy savings and reduced refrigerant charge compared to conventional embodiments. However, FIGS. 1 - 7 and the corresponding description are merely illustrative, and other components are also possible that enable the technical effects described above and / or further improve energy savings and reduce refrigerant charge.

[0056] For example, FIG. 9 is a schematic diagram of an embodiment of a multi - temperature hot water HVAC&R system 210 that employs a vapor compression assembly 212 (or chiller assembly), a free cooling assembly 214, and a control mechanism configured to regulate the dependence on the vapor compression assembly 212 and the free cooling assembly 214.

[0057] Generally, the vapor compression assembly 212 and the free cooling assembly 214 are configured to cool a process fluid 216 (e.g., water, glycol, water - glycol mixture, dielectric fluid in immersion applications, etc.) corresponding to a process fluid loop 218, and the process fluid 216 is urged through the process fluid loop 218 via one or more pumps 219a, 219b. As shown in the figure, the process fluid loop 218 may direct the process fluid 216 to one or more loads 220a, 220b. In the illustrated embodiment, load 220a is a high - temperature load and load 220b is a low - temperature load. Depending on the ambient and / or operating conditions of the HVAC&R system 210, the dependence on the vapor compression assembly 212 and / or the dependence on the free cooling assembly 214 for cooling the process fluid 216 can be adjusted to ensure proper cooling and reduce the energy consumption of the HVAC&R system 210 compared to conventional embodiments.

[0058] The vapor compression assembly 212 may include a vapor compression loop 222 (referred to in a particular example of the present disclosure as a working fluid loop), and the vapor compression loop 222 routes a working fluid 224 (e.g., a refrigerant such as R-123, R-514A, R-1224yd, R-1233zd, R-134a, R-1234ze, R-1234yf, R-1311, R-32, R-410A, or others) through various components of the vapor compression assembly 212. For example, the vapor compression loop 222 may route the working fluid 224 through a compressor 228, a condenser 226, an expansion valve 232, and an evaporator 230 of the vapor compression assembly 212. The compressor 228 may operate to urge the working fluid 224 through the vapor compression loop 222 (e.g., by increasing the pressure of the working fluid 224) in a particular state. The evaporator 230 may operate to cool a process fluid 216 of the process fluid loop 218 in a particular state. The expansion valve 232 may operate to reduce the pressure of the working fluid 224 between the condenser 226 and the evaporator 230. The condenser 226 may operate to remove heat from the working fluid 224 in a particular state through liquid-liquid cooling in which heat is transferred from the working fluid 224 to a cooling fluid 234 (e.g., water, glycol, a water-glycol mixture, etc.) corresponding to an internal fluid cooling loop 236 of the free cooling assembly 214. In this way, the condenser 226 may be regarded as part of the internal fluid cooling loop 236 while the cooling fluid 234 of the internal fluid cooling loop 236 is present in the condenser 226.

[0059] In the illustrated embodiment, the vapor compression assembly 212 includes a mechanism configured to divert some or all of the flow path of the working fluid 224 in certain conditions. For example, the valve 237 can be controlled (e.g., via the controller 246) to cause the flow of the refrigerant 224 through the heat exchanger 235 corresponding to the heat recovery path 241 that employs the heat recovery fluid 243 (e.g., water, glycol, or a water - glycol mixture) based on certain ambient and / or operating conditions. In this way, the heat recovery fluid 243 can extract heat from the working fluid 224 in the heat exchanger 235. The heat exchanger 235 can be a plate - frame heat exchanger of a welded brazed heat exchanger.

[0060] As described above, in certain ambient and / or operating conditions of the HVAC&R system 210, the free - cooling assembly 214 can be employed to reduce the dependence on the vapor compression assembly 212 for cooling the process fluid 216 of the process fluid loop 218. For example, as the dependence on the free - cooling assembly 214 increases in response to certain conditions, the dependence on the compressor 228 of the vapor compression assembly 212 can be reduced. In certain conditions, while the HVAC&R system 210 depends only on the free - cooling assembly 214 to provide cooling to the process fluid 216, the compressor 228 can be completely disconnected or otherwise turned off. The movement of the working fluid 224 through the vapor compression loop 222 can continue even after the compressor 228 is disconnected or otherwise turned off via natural convection (e.g., via a heat siphon). Additionally or alternatively, the HVAC&R system 210 can depend on both the free - cooling assembly 214 and the vapor compression assembly 212 in certain conditions where the compressor 228 is controlled to a relatively low setting, thereby improving energy efficiency while ensuring proper cooling of the process fluid 216. The aspects of the free - cooling assembly 214 and the control of the HVAC&R system 210 for adjusting the dependence on the vapor compression assembly 212 and / or the free - cooling assembly 214 will be described in detail below.

[0061] In the illustrated embodiment, the free cooling assembly 214 includes an internal fluid cooling loop 236 configured to route a cooling fluid 234 through various components of the HVAC&R system 210, including a condenser 226 of the vapor compression assembly 212, an air-cooled heat exchanger 238 (e.g., having a fan 239) of the free cooling assembly 214, and a plate-frame heat exchanger 240 of the free cooling assembly 214. Generally, the air-cooled heat exchanger 238 is configured to cool the cooling fluid 234 (e.g., via the fan 239) before the cooling fluid 234 is delivered to the condenser 226 of the vapor compression assembly 226 and / or the plate-frame heat exchanger 240 of the free cooling assembly 214. In some embodiments, the air-cooled heat exchanger 238 may include only an example of a fan 239 configured to cool the cooling fluid 234 before the cooling fluid 234 is delivered to the condenser 226 and / or the plate-frame heat exchanger 240.

[0062] When the cooling fluid 234 is present in the condenser 226, the cooling fluid 234 absorbs heat from the working fluid 224 corresponding to the vapor compression assembly 212 and condenses the working fluid 224 before the working fluid 224 is delivered to the expansion valve 232. When the cooling fluid 234 is present in the plate-frame heat exchanger 240, the cooling fluid 234 absorbs heat from the process fluid 216 corresponding to the process fluid loop 218. Aspects of the free cooling assembly 214 can be controlled to allocate some, none, or all of the cooling fluid 234 to the condenser 226 and some, none, or all of the cooling fluid 234 to the plate-frame heat exchanger 240, as will be described in detail below.

[0063] The free cooling assembly 214 includes a valve 242 controlled in various settings for directing a portion of the cooling fluid 234 to the condenser 226 of the vapor compression assembly 212 and / or to the plate frame heat exchanger 240 of the free cooling assembly 214. Further, the free cooling assembly 214 includes a pump 244 configured to urge the cooling fluid 234 through the internal fluid cooling loop 236. Depending on the ambient and / or operating conditions of the HVAC&R system 210, the valve 242 can be controlled to a first valve setting in which the cooling fluid 234 is directed to the plate frame heat exchanger 240 and blocked from the condenser 226, a second valve setting in which the cooling fluid 234 is directed to the condenser 226 and blocked from the plate frame heat exchanger 240, or a third setting (or one of several third settings) in which a portion of the cooling fluid 234 is directed to the plate frame heat exchanger 240 and an additional portion of the cooling fluid 234 is directed to the condenser 226.

[0064] The controller 246 of the HVAC&R system 210, which includes the processing circuit 248 and the memory circuit 250, can be employed to control the various components described above. For example, the controller 246 can receive one or more inputs indicating various ambient and / or operating states of the HVAC&R system 210. In fact, the controller 246 can receive a first input from the first sensor 252 indicating the ambient temperature (e.g., proximate to the air-cooled heat exchanger 238). Additionally or alternatively, the controller 246 can receive a second input from the second sensors 254a, 254b indicating the supply temperature of the process fluid 216 directed to the loads 220a, 220b. Additionally or alternatively, the controller 46 can receive a third input from the third sensors 256a, 256b indicating the return temperature of the process fluid 216 returned from the loads 220a, 220b. In some embodiments, the controller 246 can employ the target supply temperature of the process fluid 216 directed to the loads 220a, 220b, and / or the target return temperature of the process fluid 216 returned from the loads 220a, 220b (e.g., in addition to, or instead of, the detected temperature). Additionally or alternatively, the controller 246 can receive (or otherwise determine) a fourth input indicating the operating load corresponding to the HVAC&R system 210 and / or the loads 220a, 220b.

[0065] In response to at least one of the inputs described above (e.g., ambient temperature, supply temperature and / or target supply temperature of the process fluid 216, return temperature and / or target return temperature of the process fluid 216, operating load), the controller 246 can control the various components of the HVAC&R system 210 to ensure proper cooling of the loads 220a, 220b while reducing energy consumption. Specifically, the controller 246 can control the valve 242 of the free-cooling assembly 214 to direct some or all of the cooling fluid 234 to the condenser 226 of the vapor-compression assembly 212 and to direct some or all of the cooling fluid 234 to the plate-frame heat exchanger 240.

[0066] Other aspects of the HVAC&R system 210 can also be controlled to correspond to the valve settings of the valve 242 (or based on the inputs described above). For example, the settings of the compressor 228 and / or the fan 239 of the air-cooled heat exchanger 238 can be controlled in a manner that provides appropriate cooling to the process fluid 216 while reducing the energy consumption of the HVAC&R system 210. Generally, the systems and methods of the present disclosure are configured to enable the HVAC&R system 210 to provide appropriate cooling to the process fluid 216 while relying heavily on the free cooling assembly 214, thereby improving the efficiency of the HVAC&R system 210 compared to conventional embodiments.

[0067] As described above, the HVAC&R system 210 includes a heat recapture path 241 that is configured to flow the heat recapture fluid 243 through the heat exchanger 235. The heat recapture fluid 243 can also be provided to an additional heat exchanger 260 upstream of the heat exchanger 235. The additional heat exchanger 260 can be employed to receive a portion of the process fluid 216 (e.g., to cool the process fluid 216).

[0068] As described above, the HVAC&R system 210 employs a working fluid 224, a cooling fluid 234, a process fluid 216, and a heat reclamation fluid 243. In the illustrated embodiment, the HVAC&R system may employ a fifth fluid loop 262 that flows a fifth fluid 264 (e.g., water, glycol, water-glycol mixture) for additional cooling purposes. The fifth fluid loop 262 may flow the fifth fluid 264 through a cooling tower 266 and a wet economizer heat exchanger 267. A pump 268 may be employed to urge the fifth fluid 264 through the fifth fluid loop 262. In the wet economizer heat exchanger 267, the fifth fluid 264 may extract heat from the process fluid 216. Further, the cooling tower 266 may include a fan 269 that is controlled to various fan settings (e.g., by a controller 246) based on the wet bulb temperature detected by a sensor 271, the required cooling capacity, and / or the water availability such that the cooling tower 266 (e.g., the fan 269 of the cooling tower 266) provides sufficient cooling to the fifth fluid 264. In some embodiments, the pump settings of the pump 268 may also be controlled based on the wet bulb temperature detected by the sensor 271 and / or other ambient and / or operating conditions of the HVAC&R system 210.

[0069] The process fluid loop 218 of FIG. 9 also includes a series of diverter valves 270a, 270b, 270c, 270d, 270e that are controlled to various settings to cause various flows of the process fluid 216 through the various paths of the process fluid loop 218. Further, the process fluid loop 218 includes a series of bypass valves 272a, 272b, 272c that are employed to open and close the various paths within the process fluid loop 218. The controller 246 controls the diverter valves 270a, 270b, 270c, 270d, 270e, and the bypass valves 272a, 272b, 272c, 272d (e.g., based on ambient and operating conditions of the HVAC&R system) to control the flow of the process fluid 216 through the various components of the HVAC&R system 210 detailed above. An example of a multi-temperature hot water HVAC&R system with a flow control mechanism can be found in PCT / US22 / 19819, filed Mar. 20, 2022, entitled "MULTI-STAGE THERMAL MANAGEMENT SYSTEMS AND METHODS", which is hereby incorporated by reference in its entirety.

[0070] Generally, the systems and methods of the present disclosure are configured to provide appropriate cooling to one or more loads associated with an HVAC&R system, but improve energy efficiency over conventional embodiments, reduce the refrigerant charge for vapor compression compared to conventional embodiments, and the like.

[0071] Only certain features of the present embodiments have been illustrated and described herein, but many modifications and variations will occur to those skilled in the art. Accordingly, it should be understood that the appended claims are intended to cover all such modifications and variations that fall within the true spirit of the present disclosure. Further, it is understood that specific elements of the disclosed embodiments may be combined or exchanged with one another.

[0072] The technology presented and claimed in this specification is referenced and applied to material objects and specific examples of a practical nature that clearly improve the art, and thus is not abstract, intangible, or purely theoretical. Further, if any of the claims appended to the end of this specification include one or more elements designated as "means for [performing a function]" or "steps for [performing a function]," such elements are intended to be construed under 35 U.S.C. § 112(f). However, for any claims that include elements specified in other ways, such elements are not intended to be construed under 35 U.S.C. § 112(f).

Claims

1. An HVAC&R system, which is a heating, ventilation, air conditioning, and / or refrigeration system, comprising: a vapor compression assembly; a free cooling assembly corresponding to a cooling fluid and comprising an air-cooled heat exchanger, an additional heat exchanger, a pump, and a valve; at least one controller, wherein the at least one controller is configured to: receive data indicating ambient conditions, operating conditions, or both of the HVAC&R system; based on the data, operate the valve between a first setting in which the cooling fluid is directed to the additional heat exchanger and blocked from a condenser of the vapor compression assembly, a second setting in which the cooling fluid is directed to the condenser and blocked from the additional heat exchanger, and a third setting in which a first portion of the cooling fluid is directed to the additional heat exchanger and a second portion of the cooling fluid is directed to the condenser.

2. The HVAC&R system according to claim 1, further comprising a process fluid loop configured to direct a process fluid through an evaporator, a load, and the additional heat exchanger of the vapor compression assembly.

3. The HVAC&R system according to claim 1, further comprising a sensor configured to detect an ambient temperature corresponding to the ambient conditions, wherein the at least one controller is configured to receive the data indicating the ambient temperature corresponding to the ambient conditions from the sensor.

4. The HVAC&R system according to claim 1, wherein the at least one controller is configured to control a fan setting of a fan of the air-cooled heat exchanger based on the data.

5. The HVAC&R system according to claim 1, wherein the at least one controller is configured to control a compressor setting of a compressor of the vapor compression assembly based on the data.

6. The HVAC&R system according to claim 1, wherein the at least one controller is configured to control a pump setting of the pump based on the data, and the pump is configured to urge the cooling fluid through the free cooling assembly.

7. The HVAC&R system according to claim 1, wherein the additional heat exchanger comprises a plate-frame heat exchanger.

8. The at least one controller is configured to receive an input indicative of an operating load or a cooling demand of a load corresponding to the HVAC&R system, and the input corresponds to the data indicative of the operating state of the HVAC&R system. The HVAC&R system according to claim 1.

9. The at least one controller is configured to receive one or more inputs indicative of a return temperature of the cooling fluid from a load corresponding to the HVAC&R system, a supply temperature of the cooling fluid to the load, or both, and the one or more inputs correspond to the data indicative of the operating state of the HVAC&R system. The HVAC&R system according to claim 1.

10. The at least one controller is configured to receive one or more inputs indicative of a target return temperature of the cooling fluid from a load corresponding to the HVAC&R system, a target supply temperature of the cooling fluid to the load, or both, and the one or more inputs correspond to the data indicative of the operating state of the HVAC&R system. The HVAC&R system according to claim 1.

11. Comprising a heat recapture path, the heat recapture path A first heat recapture heat exchanger configured to receive the cooling fluid and the heat recapture fluid; A second heat recapture heat exchanger disposed downstream of the first heat recapture heat exchanger on the heat recapture path and configured to receive the heat recapture fluid and the working fluid of the vapor compression assembly. The HVAC&R system according to claim 1.

12. An additional cooling loop corresponding to an additional cooling fluid; A wet economizer heat exchanger configured to receive a process fluid and the additional cooling fluid. The HVAC&R system according to claim 1.

13. The additional cooling loop comprises a cooling tower and a pump configured to urge the additional cooling fluid between the wet economizer heat exchanger and the cooling tower. The HVAC&R system according to claim 12, wherein the at least one controller is configured to control a fan setting of a fan of the cooling tower based on at least one of a required cooling capacity or water availability.

14. A process fluid loop configured to direct a process fluid through an evaporator of the vapor compression assembly, the additional heat exchanger, a high temperature load, and a low temperature load, and A plurality of valves disposed within the process fluid loop, and A controller configured to operate the plurality of valves to control one or more flows of the process fluid to the high temperature load and the low temperature load, the HVAC&R system according to claim 1.

15. The HVAC&R system according to claim 14, wherein the controller is configured to operate the plurality of valves based on the data.

16. A control assembly for an HVAC&R system that is a heating, ventilation, air conditioning, and / or refrigeration system, the control assembly comprising A sensor configured to detect an ambient or operating condition of the HVAC&R system, and At least one controller, the at least one controller being Receiving feedback indicative of the ambient or operating condition from the sensor, and Based on the feedback, operating a valve of a free cooling assembly among a plurality of settings, the plurality of settings including a first setting in which a cooling fluid of the free cooling assembly is directed towards a heat exchanger of the free cooling assembly rather than the vapor compression assembly, a second setting in which the cooling fluid is directed towards the vapor compression assembly rather than the heat exchanger, and at least one third setting in which a first portion of the cooling fluid is directed towards the heat exchanger and a second portion of the cooling fluid is directed towards the vapor compression assembly.

17. The control assembly according to claim 16, wherein the at least one controller is configured to control a fan setting of a fan of an air-cooled heat exchanger of the free cooling assembly based on the feedback, the air-cooled heat exchanger being separate from the heat exchanger.

18. The control assembly according to claim 16, wherein the at least one controller is configured to control a compressor setting of a compressor of the vapor compression assembly based on the feedback.

19. The control assembly according to claim 16, wherein the at least one controller is configured to control a pump setting of a pump of the free cooling assembly based on the feedback, and the pump is configured to urge the cooling fluid through the free cooling assembly.

20. The control assembly according to claim 16, wherein the at least one controller is configured to actuate the valve among the plurality of settings based on additional feedback that is separate from the feedback and indicates an operating load or a cooling demand.

21. The control assembly according to claim 16, wherein the at least one controller is configured to control a plurality of valves corresponding to an evaporator of the vapor compression assembly, the heat exchanger of the free cooling assembly, and a process fluid loop configured to direct a process fluid through a load based on the feedback.

22. A method of operating an HVAC&R system, which is a heating, ventilation, air conditioning, and / or refrigeration system, comprising: receiving, via at least one controller, first data indicating a first value of an ambient state or an operating state of the HVAC&R system; controlling, via the at least one controller and based on the first data, a valve to a first setting in which a cooling fluid of a free cooling assembly is directed toward a heat exchanger of the free cooling assembly rather than a condenser of a vapor compression assembly; receiving, via the at least one controller, second data indicating a second value of the ambient state or the operating state of the HVAC&R system, the second value being different from the first value; controlling, via the at least one controller and based on the second data, the valve to a second setting in which the cooling fluid is directed toward the condenser rather than the heat exchanger. Receiving, via the at least one controller, third data indicative of a third value of the ambient or operating state of the HVAC&R system, wherein the third value is different from the first value and the second value. Controlling the valve to a third setting via the at least one controller and based on the third data, wherein a first portion of the cooling fluid is directed toward the heat exchanger and a second portion of the cooling fluid is directed toward the condenser. A method comprising.

23. When the cooling fluid is present in the condenser, sinking heat from the working fluid of the vapor compression assembly to the cooling fluid. The method of claim 22, comprising sinking heat from the process fluid of the process fluid loop to the cooling fluid when the cooling fluid is present in the heat exchanger.

24. The method of claim 23, comprising directing the process fluid of the process fluid loop between the load and the evaporator of the vapor compression assembly, the heat exchanger of the free cooling assembly, or both.

25. The method of claim 22, comprising cooling the cooling fluid via an air-cooled heat exchanger of the free cooling assembly.

26. Controlling a fan setting of a fan of the air-cooled heat exchanger via the at least one controller based on the first value at a first time point, the second value at a second time point different from the first time point, and the third value at a third time point different from the first time point and the second time point. The method of claim 25.

27. The method of claim 22, comprising controlling the valve via the at least one controller based on an operating load or cooling demand of the HVAC&R system.

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