CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from and the benefit of U.S. Provisional Application Serial No. 63/350,743, entitled “LOW CHARGE CHILLER AND FREE COOLING,” filed June 9, 2022, which is hereby incorporated by reference in its entirety for all purposes.

BACKGROUND

[0002] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

[0003] This application relates generally to heating, ventilating, air conditioning, and/or refrigeration (HVAC&R) systems employing 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. Vapor compression assemblies utilize a working fluid (e.g., a refrigerant) that changes phases between vapor, liquid, and combinations thereof in response to exposure to different temperatures and pressures within components of the vapor compression assembly. The vapor compression assembly may include an evaporator configured to place the working fluid in a heat exchange relationship with, for example, a conditioning or process fluid (e.g., water), such that the working fluid absorbs heat from the process fluid. The process fluid, cooled by the working fluid, may then be directed towards a conditioned environment, such as a data center, serviced by the HVAC&R system. The process fluid may be passed through downstream equipment, such as air handlers, to condition other fluids, such as air directed into the conditioned environment. A condenser of the vapor compression assembly may be employed to receive the working fluid and condense the working fluid into liquid phase. A compressor of the vapor compression assembly may be employed to bias the working fluid through the vapor compression assembly (e.g., by increasing a pressure of the working fluid).

[0005] In certain HVAC&R systems employing 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 may be employed to cool various fluids associated with the HVAC&R system, such as the working fluid in the condenser of the vapor compression assembly. Further, a cooling tower (or other cooling source) may be employed in the free cooling assembly to reduce a temperature of the process fluid via ambient air. In this way, the free cooling assembly may leverage a relatively low ambient air temperature for providing cooling and reducing a load on the vapor compression assembly.

[0006] In traditional systems, operation of the free cooling assembly may be activated during certain conditions, such as when ambient air temperature is relatively low. When the ambient air temperature is relatively low, the HVAC&R system may be configured to operate, via the free cooling assembly, at an adequate cooling capacity without powering the compressor (e.g., by relying on a thermosiphon or natural convection for movement of the working fluid) and/or while reducing a reliance on the compressor (or other components) of the vapor compression assembly. However, in traditional HVAC&R systems utilizing vapor compression and free cooling assemblies, technical constraints may require that reliance on the vapor compression assembly be prioritized over reliance on the free cooling assembly. That is, in traditional HVAC&R systems, cooling may rely heavily on the vapor compression assembly, which requires a relatively large refrigerant charge in the vapor compression assembly and contributes to energy inefficiencies of the HVAC&R system. Accordingly, it is now recognized that improved HVAC&R systems employing vapor compression and free cooling assemblies are desired.

SUMMARY

[0007] A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.

[0008] In one embodiment, an HVAC&R system includes a vapor compression assembly and a free cooling assembly. The free cooling assembly corresponds to a cooling fluid (e.g., in an internal fluid cooling loop) and includes an air cooled heat exchanger, one or more additional heat exchangers, a fluid pump, and a valve. The HVAC&R system also includes at least one controller configured to receive data indicative of an ambient condition, an operating condition of the HVAC&R system, or both. The at least one controller is also configured to actuate, based on the data, the valve between various settings. The various settings include 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.

[0009] In another embodiment, a control assembly of a heating, ventilation, air conditioning, and/or refrigeration (HVAC&R) system includes a sensor configured to detect an ambient condition or operating condition of the HVAC&R system, and at least one controller. The at least one controller is configured to receive, from the sensor, feedback indicative of the ambient condition or operating condition. The at least one controller is also configured to actuate, based on the feedback, a valve of a free cooling assembly between various settings. The various settings include a first setting in which a cooling fluid of the free cooling assembly is directed toward a heat exchanger of the free cooling assembly and not a vapor compression assembly, a second setting in which the cooling fluid is directed toward the vapor compression assembly and not the heat exchanger, and at least one third setting in which 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 vapor compression assembly.

[0010] In still 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 condition or operating condition of the HVAC&R system, and 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 and not a condenser of a vapor compression assembly. The method also includes receiving, via the at least one controller, second data indicative of a second value of the ambient condition or operating condition of the HVAC&R system, the second value being different than the first value, and 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 and not the heat exchanger. The method also includes receiving, via the at least one controller, third data indicative of a third value of the ambient condition or operating condition of the HVAC&R system, the third value being different than the first value and the second value, and controlling, via the at least one controller and based on the third data, the valve to a third setting in which 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.

DRAWINGS

[0011] Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which: [0012] FIG. 1 is a schematic view of a heating, ventilating, air conditioning, and/or refrigeration (HVAC&R) system employing a vapor compression assembly (or chiller assembly), a free cooling assembly, and control features configured to modulate a reliance on the vapor compression assembly and the free cooling assembly, in accordance with an aspect of the present disclosure;

[0013] FIG. 2 is a schematic view of the HVAC&R system in FIG. 1 where ambient temperature is 85 degrees Fahrenheit and an operating load is 100% of system design load capacity, in accordance with an aspect of the present disclosure;

[0014] FIG. 3 is a schematic view of the HVAC&R system in FIG. 1 where ambient temperature is 65 degrees Fahrenheit and an operating load is 100% of system design load capacity, in accordance with an aspect of the present disclosure;

[0015] FIG. 4 is a schematic view of the HVAC&R system in FIG. 1 where ambient temperature is 60 degrees Fahrenheit and an operating load is 100% of system design load capacity, in accordance with an aspect of the present disclosure;

[0016] FIG. 5 is a schematic view of the HVAC&R system in FIG. 1 where ambient temperature is 85 degrees Fahrenheit and an operating load is 50% of system design load capacity, in accordance with an aspect of the present disclosure;

[0017] FIG. 6 is a schematic view of the HVAC&R system in FIG. 1 where ambient temperature is 65 degrees Fahrenheit and an operating load is 50% of system design load capacity, in accordance with an aspect of the present disclosure;

[0018] FIG. 7 is a schematic view of the HVAC&R system in FIG. 1 where ambient temperature is 60 degrees Fahrenheit and an operating load is 50% of system design load capacity, in accordance with an aspect of the present disclosure;

[0019] FIG. 8 is a process flow diagram illustrating a method of operating the

HVAC&R system of FIG. 1, in accordance with an aspect of the present disclosure; and [0020] FIG. 9 is a schematic view of a multi-temperature hydronic HVAC&R system employing a vapor compression assembly (or chiller assembly), a free cooling assembly, and control features configured to modulate a reliance on the vapor compression assembly and the free cooling assembly, in accordance with an aspect of the present disclosure.

DETAILED DESCRIPTION

[0021] One or more specific embodiments will be described below. Tn an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0022] When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0023] Embodiments of the present disclosure relate to a heating, ventilating, air conditioning, and/or refrigeration (HVAC&R) system utilizing a vapor compression assembly and a free cooling assembly. The vapor compression assembly may be employed, for example, in the context of a chiller utilized to cool a conditioning or process fluid during certain conditions. In general, the HVAC&R system is configured to cool the process fluid and route the process fluid towards a load. For example, the process fluid may be cooled by the HVAC&R system and guided to downstream equipment, such as an air handling unit (AHU). The AHU may cool an air flow via the process fluid and distribute the air flow to various spaces (e.g., rooms, data centers) conditioned by the HVAC&R system. Alternatively, the process fluid may be employed to directly cool a load, such as equipment of the data center, in a liquid immersion application.

[0024] The vapor compression assembly may include a vapor compression loop (referred to in certain instances of the present disclosure as a working fluid loop) that circulates a working fluid (e.g., refrigerant) through an evaporator, a condenser, and a compressor. The compressor may operate to compress (e.g., increase a pressure of) the working fluid in certain conditions, thereby biasing the working fluid through the vapor compression loop. The evaporator may be employed to cool the process fluid by absorbing heat from the process fluid into the working fluid in certain conditions. The condenser may 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 in certain conditions. In this way, the condenser may be considered a part of the internal fluid cooling loop while the cooling fluid of the internal fluid cooling loop is present at the condenser.

[0025] 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-to-liquid cooling. For example, 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. The air cooled heat exchanger, which may include a single fan (e g., a single fan serving a V-shaped coil assembly), may be employed to reduce a temperature of the cooling fluid prior to the cooling fluid being directed towards the plate frame heat exchanger and/or the condenser of the vapor compression assembly. [0026] The valve (e.g., flow diverting valve) of the free cooling assembly may be disposed in the 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 to 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 to the condenser. Tn 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 an additional portion of the cooling fluid to the condenser. In accordance with the present disclosure, the controller may receive various inputs indicative of ambient conditions (e.g., ambient temperature, referred to in certain instances of the present disclosure as ambient dry bulb temperature) and/or operating conditions of the HVAC&R system (e.g., a return temperature or target return temperature of the process fluid from the load, a supply temperature or target supply temperature of the process fluid to the load, an operating load, etc.). Based on one or more of these inputs, the controller may actuate the valve to the preferred valve setting such that the cooling fluid is directed towards appropriate components of the HVAC&R system as described above and in detail below.

[0027] It should be noted that a number of valve settings of the valve may exist for directing 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 for directing a portion of the cooling fluid to the plate frame heat exchanger and an additional portion of the cooling fluid to the condenser, and a pump may be controlled to modulate an amount or flow rate of the portion and additional portion of the cooling fluid based on various conditions. In this way, an amount or flow rate of the portion of the cooling fluid directed to the plate frame heat exchanger and an additional amount or additional flow rate of the additional portion of the cooling fluid directed to the condenser may be controlled to provide adequate cooling to the cooling fluid (and subsequently the load) while minimizing a reliance on the vapor compression assembly.

[0028] Further to the points above, a setting of the compressor of the vapor compression system, which operates to increase a pressure of the working fluid in the vapor compression loop, may be controlled by the controller to correspond with the valve setting, to correspond with the pump setting, and/or based on the above-described ambient and/or operating conditions. Further still to the points above, the fan of the air cooled heat exchanger may be controlled to a setting to provide sufficient cooling to the cooling fluid of the free cooling assembly. Other control aspects are also possible and described in detail with reference to the drawings.

[0029] By employing the above-described features, the HVAC&R system may be capable of providing cooling to a conditioned space, such as a data center, via substantial reliance on the free cooling assembly and a relatively low reliance on the vapor compression assembly, thereby providing adequate cooling while improving energy efficiency and reducing a refrigerant charge of the vapor compression assembly relative to traditional embodiments. As an example, for an HVAC&R system having a system design load capacity of 500 refrigeration tons in which an operating load is 100% of the system design load capacity, a supply temperature of the process fluid at 70 degrees Fahrenheit may be enabled via complete reliance on the free cooling assembly (e.g., with the compressor of the vapor compression assembly turned off) at least when the ambient temperature is approximately 60 degrees Fahrenheit or less. Further, if the operating load is reduced, the supply temperature of the process fluid at 70 degrees Fahrenheit may be enabled via complete reliance 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 design load capacity, the HVAC&R system may be capable of providing adequate cooling as described above via complete reliance on the free cooling assembly (e.g., with the compressor of the vapor compression assembly turned off) when ambient temperature is approximately 65 degrees Fahrenheit or less. Of course, at even higher ambient temperatures, the HVAC&R system may rely heavily on the free cooling assembly to provide the process fluid at adequate temperatures for cooling the load. Other examples are provided with reference to the drawings.

[0030] In general, presently disclosed systems and methods enable cooling with a heavier reliance on the free cooling and a reduced reliance on vapor compression compared to traditional embodiments. In doing so, a necessary refrigerant charge of the vapor compression assembly is reduced relative to traditional embodiments, and an energy efficiency of the HVAC&R system is improved relative to traditional embodiments. These and other features are described in detail below with reference to the drawings.

[0031] FIG. 1 is a schematic view of an embodiment of an HVAC&R system 10 employing a vapor compression assembly 12 (or chiller assembly), a free cooling assembly 14, and control features configured to modulate a reliance on the vapor compression assembly 12 and the free cooling assembly 14. In general, the vapor compression assembly 12 and the free cooling assembly 14 are configured to cool a process fluid 16 (e.g., water, glycol, a water-glycol mixture, a dielectric fluid in liquid immersion applications, etc.) corresponding to a process fluid loop 18, where the process fluid 16 is biased through the process fluid loop 18 via a pump 19. As shown, the process fluid loop 18 may guide the process fluid 16 to a load 20 (e.g., a condition space and/or data center) for cooling the load 20. Depending on ambient conditions and/or operating conditions of the HVAC&R system 10, a reliance on the vapor compression assembly 12 and/or a reliance on the free cooling assembly 14 for cooling the process fluid 16 may be modulated to ensure adequate cooling and reduce energy consumption of the HVAC&R system 10 relative to traditional embodiments. These and other features are described in detail below with reference to FIG. 1.

[0032] The vapor compression assembly 12 may include a vapor compression loop 22 (referred to in certain instances of the present disclosure as a working fluid loop) that 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 may 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 may operate to bias the working fluid 24 through the vapor compression loop 22 (e.g., by increasing a pressure of the working fluid 24) in certain conditions. The evaporator 30 may operate to cool the process fluid 16 of the process fluid loop 18 in certain conditions. The expansion valve 32 may operate to reduce a pressure of the working fluid 22 between the condenser 26 and the evaporator 30. The condenser 26 may operate to remove heat from the working fluid 24 in certain conditions via fluid-to- 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 may 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 at the condenser 26.

[0033] As previously described, in certain ambient conditions and/or operating conditions of the HVAC&R system 10, the free cooling assembly 14 may be employed to reduce a reliance on the vapor compression assembly 12 for cooling the process fluid 16 of the process fluid loop 18. For example, as a reliance on the free cooling assembly 14 is increased in response to certain conditions, a reliance on the compressor 28 of the vapor compression assembly 12 may be reduced. In certain conditions, the compressor 28 may be entirely disconnected or otherwise turned off while the HVAC&R system 10 relies only on the free cooling assembly 14 to provide cooling to the process fluid 16. Movement of the working fluid 24 through the vapor compression loop 22 may continue after the compressor 28 is disconnected or otherwise turned off via natural convection (e g., via a thermosiphon). 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 with the compressor 28 controlled to a relatively low setting, thereby improving energy efficiency while ensuring adequate cooling of the process fluid 16. Aspects of the free cooling assembly 14 and control of the HVAC&R system 10 to modulate reliance on the vapor compression assembly 12 and/or the free cooling assembly 14 are described in detail below.

[0034] In the illustrated embodiment, the free cooling assembly 14 includes the internal fluid cooling loop 36 configured to route the cooling fluid 34 through various components of the HVAC&R system 10, including the condenser 26 of the vapor compression assembly 12, an air cooled heat exchanger 38 (e.g., having a fan 39) of the free cooling assembly 14, and a plate frame heat exchanger 40 of the free cooling assembly 14. In general, the air cooled heat exchanger 38 is configured to cool the cooling fluid 34 (e.g., via the fan 39) prior to delivery of the cooling fluid 34 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 one instance of the fan 39 configured to cool the cooing fluid 34 prior to delivery of the cooling fluid 34 to the condenser 26 and/or the plate frame heat exchanger 40.

[0035] When the cooling fluid 34 is present at the condenser 26, the cooling fluid 34 absorbs heat from the working fluid 24 corresponding to the vapor compression assembly 12, causing the working fluid 24 to condense prior to delivery of the working fluid 24 to the expansion valve 32. When the cooling fluid 34 is present at 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 may 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 described in detail below.

[0036] The free cooling assembly 14 includes a valve 42 controlled to various settings to direct portions of the cooling fluid 34 to 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 bias the cooling fluid 34 through the internal fluid cooling 36. Depending on the ambient conditions and/or operating conditions of the HVAC&R system 10, the valve 42 may be controlled to a first valve setting in which the cooling fluid 34 is directed to the plate frame heat exchanger 40 and blocked from the condenser 26, a second valve setting in which the cooling fluid 34 is directed to the condenser 26 and blocked from the plate frame heat exchanger 40, or a third setting (or one of a number of third settings) in which a portion of the cooling fluid 34 is directed to the plate frame heat exchanger 40 and an additional portion of the cooling fluid 34 is directed to the condenser 26.

[0037] A controller 46 of the HVAC&R system 10 may be employed to control various of the above-described components. In the illustrated embodiment, the controller 46 includes processing circuitry 48 and memory circuitry 50 having instructions stored thereon that, when executed by the processing circuitry 48, cause the processing circuitry 48 to perform various functions. It should be noted that, for brevity, only one instance of the controller 46 is shown in the illustrated embodiment. However, it should be noted that multiple controllers (including dedicated processing and/or memory circuitry) may be employed to implement the control features described in the present disclosure.

[0038] The controller 46 may receive one or more inputs indicative of various ambient conditions and/or operating conditions of the HVAC&R system 10. For example, the controller 46 may receive, from a first sensor 52, a first input indicative of an ambient temperature (e.g., proximate the air cooled heat exchanger 38). Additionally or alternatively, the controller 46 may receive, from a second sensor 54, a second input indicative of a supply temperature of the process fluid 16 directed to the load 20. Additionally or alternatively, the controller 46 may receive, from a third sensor 56, a third input indicative of a return temperature of the process fluid 16 returned from the load 20. In some embodiments, the controller 46 may employ a target supply temperature of the process fluid 16 directed to the load 20 and/or a target return temperature of the process fluid 16 returned from the load 20 (e.g., in addition to, or in the alternate of, the detected temperatures). Additionally or alternatively, the controller 46 may receive (or otherwise determine) a fourth input indicative of an operating load or cooling demand corresponding to the HVAC&R system 10 and/or the load 20. Indeed, while the HVAC&R system 10 may include a system design load capacity, a cooling demand of the load 20 at certain operating intervals may correspond to an operating load that is less than the system design load capacity. The fourth input indicative of the operating load or cooling demand may be, for example, a percentage of the system design load capacity. The fourth input may be received from a sensor or other feedback device, which may be a part of (or separate from) the one or more controllers 46. A control assembly, in accordance with the present disclosure, may include the one or more controllers 46 and, in some embodiments, any combination of the first sensor 52, the second sensor 54, the third sensor 56, and/or other sensor or feedback devices.

[0039] In response to at least one of the above-described inputs (e.g., the ambient temperature, the supply temperature and/or target supply temperature of the process fluid 16, the return temperature and/or target return temperature of the process fluid 16, the operating load), the controller 46 may control various components of the HVAC&R system 10 to ensure adequate cooling of the load 20 while reducing energy consumption. In particular, 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 some or all of the cooling fluid 34 to the plate frame heat exchanger 40.

[0040] 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 above-described inputs). For example, a setting of the compressor 28 and/or a setting of the fan 39 of the air cooled heat exchanger 38 may be controlled in a manner that provides adequate cooling to the process fluid 16 while reducing an energy consumption of the HVAC&R system 10. In general, presently disclosed systems and methods are configured to enable the HVAC&R system 10 to provide adequate cooling to the process fluid 16 while relying heavily on the free cooling assembly 14, thereby improving efficiency of the HVAC&R system 10 relative to traditional embodiments. [0041] FIGS. 2-7 illustrate various embodiments of the HVAC&R system 10 in which ambient temperature and operating load differs. As seen in FIGS. 2-7 and described in detail below, controls are modulated based at least in part on the ambient temperature and operating load. In FIGS. 2-4, operating load is 100% of system design load capacity (e.g., at ambient temperatures of 85 degrees Fahrenheit, 65 degrees Fahrenheit, and 60 degrees Fahrenheit, respectively). In FIGS. 5-7, operating load is 50% of system design load capacity (e.g., at ambient temperatures of 85 degrees Fahrenheit, 65 degrees Fahrenheit, and 60 degrees Fahrenheit, respectively). In general, the lower the ambient temperature and/or operating load, the more the HVAC&R system 10 relies on the free cooling assembly 14 for energy savings. Each of FIGS. 2-7 is described individually and in detail below.

[0042] FIG. 2 is a schematic view of an embodiment of the HVAC&R system 10 in FIG. 1, where ambient temperature is 85 degrees Fahrenheit and an operating load is 100% of system design load capacity (e.g., as shown in legend 59). Further, a supply temperature of the process fluid 16 to the load 20 is 70 degrees Fahrenheit, and a 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 towards 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 relies on the vapor compression assembly 12 (e.g., with the compressor 28 turned on and controlled to a sufficient setting) for cooling the process fluid 16 via the evaporator 30, and does not rely on the plate frame heat exchanger 40. That is, none of the cooling fluid 34 is directed towards the plate frame heat exchanger 40.

[0043] The illustrated controls rely on the vapor compression assembly 12 as shown due to the relatively high ambient temperature (e.g., 85 degrees Fahrenheit) and operating load (e.g., 100% of system design load capacity). Indeed, 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 approximately 93 degrees Fahrenheit with an approximately 600 gallons-per-minute (GPM) flow rate, and such that none of the cooling fluid 34 is routed to the plate frame heat exchanger 40.

[0044] In addition to adjusting the valve setting of the valve 42 as described above, the controller 46 may also adjust a pump setting of the pump 44 associated with the internal fluid cooling loop 36 of the free cooling assembly 14, a compressor setting of the compressor 28 associated with the vapor compression loop 22 of the vapor compression assembly 12, a pump setting of the pump 19 associated with the process fluid loop 18, a fan setting of the fan 39 of the air cooled heat exchanger 38, or any combination thereof Various performance and results data are illustrated in FIG. 2 and associated with the above-described conditions, including parameters associated with the compressor 28, the condenser 26, the evaporator 30, the air cooled heat exchanger 38 (or fan 39 thereof), the plate frame heat exchanger 40, the load 20, the valve 42, the pump 44, the pump 19, temperatures of various fluids, flow rates of various fluids, power consumption of various componentry, etc. Further, as shown in block 60, a total chiller kilowatts per refrigeration ton (kW/Ton) with the illustrated conditions and control features is 0.690.

[0045] FIG. 3 is a schematic view of an embodiment of the HVAC&R system 10 in FIG. 1, where ambient temperature is 65 degrees Fahrenheit and an operating load is 100% of system design load capacity (e.g., as shown in legend 59). Further, a supply temperature of the process fluid 16 to the load 20 is 70 degrees Fahrenheit, and a 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 a first portion of the cooling fluid 34 is directed towards the condenser 26 of the vapor compression assembly 12 (e g., at a first flow rate) and a second portion of the free cooling fluid 34 is directed towards the plate frame heat exchanger 40 of the free cooling assembly 14 (e.g., at a second flow rate). Thus, the HVAC&R system 10 relies on the vapor compression assembly 12 (e.g., with the compressor 28 turned on and controlled to a sufficient setting) for cooling the process fluid 16 via the evaporator 30, and the free cooling assembly 14 for cooling the process fluid 16 via the plate frame heat exchanger 40.

[0046] The illustrated controls rely 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 shown due to the relatively moderate temperature (e g., 65 degrees Fahrenheit) and high operating load (e.g., 100% of system design load capacity). 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 approximately 67 degrees Fahrenheit with an approximately 200 GPM flow rate, and such that the portion of the cooling fluid 34 routed to the plate frame heat exchanger 40 is approximately 67 degrees Fahrenheit with an approximately 400 GPM flow rate. Of course, if the ambient temperature rises from 65 degrees Fahrenheit, the valve 42 and/or the pump 44 of the free cooling assembly 14 may be controlled such that the flow rate of the cooling fluid 34 directed towards the condenser 26 is greater than approximately 200 GPM and the flow rate of the cooling fluid 34 directed towards the plate frame heat exchanger 40 is less than approximately 400 GPM. Additionally, if the ambient temperature drops from 65 degrees Fahrenheit, the valve 42 and/or the pump 44 of the free cooling assembly 14 may be controlled such that the flow rate of the cooling fluid 34 directed towards the condenser 26 is less than approximately 200 GPM and the flow rate of the cooling fluid 34 directed towards the plate frame heat exchanger 40 is greater than approximately 400 GPM.

[0047] In addition to adjusting the valve setting of the valve 42 as described above, the controller 46 may also adjust a pump setting of the pump 44 associated with the internal fluid cooling loop 36 of the free cooling assembly 14, a compressor setting of the compressor 28 associated with the vapor compression loop 22 of the vapor compression assembly 12, a pump setting of the pump 19 associated with the process fluid loop 18, a fan setting of the fan 39 of the air cooled heat exchanger 38, or any combination thereof. Various performance and results data are illustrated in FIG. 3 and associated with the above-described conditions, including parameters associated with the compressor 28, the condenser 26, the evaporator 30, the air cooled heat exchanger 38 (or fan 39 thereof), the plate frame heat exchanger 40, the load 20, the valve 42, the pump 44, the pump 19, temperatures of various fluids, flow rates of various fluids, power consumption of various componentry, etc. Further, as shown in block 60, a total chiller kW/Ton with the illustrated conditions and control features is 0.089, substantially lower than the embodiment illustrated in FIG. 2.

[0048] FIG. 4 is a schematic view of an embodiment of the HVAC&R system 10 in FIG. 1, where ambient temperature is 60 degrees Fahrenheit and an operating load is 100% of system design load capacity (e.g., as shown in legend 59). Further, a supply temperature of the process fluid 16 to the load 20 is 70 degrees Fahrenheit, and a 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 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 controls rely on the free cooling assembly 14 (and not the vapor compression assembly 12) as shown due to the relatively low ambient temperature (e g., 60 degrees Fahrenheit) despite the high operating load (e.g., 100% of system design load capacity).

[0049] In addition to adjusting the valve setting of the valve 42 as described above, the controller 46 may also adjust a pump setting of the pump 44 associated with the internal fluid cooling loop 36 of the free cooling assembly 14, a compressor setting of the compressor 28 associated with the vapor compression loop 22 of the vapor compression assembly 12, a pump setting of the pump 19 associated with the process fluid loop 18, a fan setting of the fan 39 of the air cooled heat exchanger 38, or any combination thereof. Various performance and results data are illustrated in FIG. 4 and associated with the above-described conditions, including parameters associated with the compressor 28, the condenser 26, the evaporator 30, the air cooled heat exchanger 38 (or fan 39 thereof), the plate frame heat exchanger 40, the load 20, the valve 42, the pump 44, the pump 19, temperatures of various fluids, flow rates of various fluids, power consumption of various componentry, etc. Further, as shown in block 60, a total chiller kW/Ton with the illustrated conditions and control features is 0.030, substantially lower than the embodiments illustrated in FIGS. 2 and 3.

[0050] FIG. 5 is a schematic view of an embodiment of the HVAC&R system 10 in FIG. 1, where ambient temperature is 85 degrees Fahrenheit and an operating load is 50% of system design load capacity (e.g., as shown in legend 59). Further, a supply temperature of the process fluid 16 to the load 20 is 70 degrees Fahrenheit, and a 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 a portion of the cooling fluid 34 is directed towards the condenser 26 of the vapor compression assembly 12 (e.g., at a first flow rate) and a second portion of the free cooling fluid 34 is directed towards the plate frame heat exchanger 40 of the free cooling assembly 14 (e.g., at a second flow rate). Thus, the HVAC&R system 10 relies on the vapor compression assembly 12 (e.g., with the compressor 28 turned on and controlled to a sufficient setting) for cooling the process fluid 16 via the evaporator 30, and the HVAC&R system 10 relies on the plate frame heat exchanger 40 of the free cooling assembly 14 for cooling the process fluid 16.

[0051] The illustrated controls rely 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 shown due to the relatively low operating load (e.g., 50% of system design load capacity) despite the 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 approximately 89 degrees Fahrenheit with an approximately 137 GPM flow rate, and such that the portion of the cooling fluid 34 routed to the plate frame heat exchanger 40 is approximately 89 degrees Fahrenheit with an approximately 163 GPM flow rate. Of course, if the ambient temperature rises from 85 degrees Fahrenheit, the valve 42 and/or the pump 44 of the free cooling assembly 14 may be controlled such that the flow rate of the cooling fluid 34 directed towards the condenser 26 is greater than approximately 137 GPM and the flow rate of the cooling fluid 34 directed towards the plate frame heat exchanger 40 is less than approximately 163 GPM. Additionally, if the ambient temperature drops from 85 degrees Fahrenheit, the valve 42 and/or the pump 44 of the free cooling assembly 14 may be controlled such that the flow rate of the cooling fluid 34 directed towards the condenser 26 is less than approximately 137 GPM and the flow rate of the cooling fluid 34 directed towards the plate frame heat exchanger 40 is greater than approximately 163 GPM. Similar adjustments may be made based on a change to the operating load.

[0052] In addition to adjusting the valve setting of the valve 42 as described above, the controller 46 may also adjust a pump setting of the pump 44 associated with the internal fluid cooling loop 36 of the free cooling assembly 14, a compressor setting of the compressor 28 associated with the vapor compression loop 22 of the vapor compression assembly 12, a pump setting of the pump 19 associated with the process fluid loop 18, a fan setting of the fan 39 of the air cooled heat exchanger 38, or any combination thereof. Various performance and results data are illustrated in FIG. 5 and associated with the above-described conditions, including parameters associated with the compressor 28, the condenser 26, the evaporator 30, the air cooled heat exchanger 38 (or fan 39 thereof), the plate frame heat exchanger 40, the load 20, the valve 42, the pump 44, the pump 19, temperatures of various fluids, flow rates of various fluids, power consumption of various componentry, etc. Further, as shown in block 60, a total chiller kW/Ton with the illustrated conditions and control features is 0.380, substantially lower than the embodiment illustrated in FIG. 2. Indeed, although the ambient temperature is 85 degrees Fahrenheit in both of FIGS. 2 and 5, the lower operating load in FIG. 5 than in FIG. 2 enables reliance at least in part on the free cooling assembly 14, thereby reducing the total chiller kW/Ton.

[0053] FIG. 6 is a schematic view of an embodiment of the HVAC&R system 10 in FIG. 1, where ambient temperature is 65 degrees Fahrenheit and an operating load is 50% of system design load capacity (e.g., as shown in legend 59). Further, a supply temperature of the process fluid 16 to the load 20 is 70 degrees Fahrenheit, and a 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 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 relies on the plate frame heat exchanger 40 of the free cooling assembly 14 for cooling the process fluid 16 of the process fluid loop 18, and does not rely on the evaporator 30 of the vapor compression assembly 12 for cooling the process fluid 16 of the process fluid loop 18. The illustrated controls rely on the free cooling assembly 14 (and not the vapor compression assembly 12, which may include the compressor 28 disconnected or otherwise turned off) as shown due to the relatively moderate ambient temperature (e.g., 65 degrees Fahrenheit) and relatively low operating load (e.g., 50% of system design load capacity).

[0054] In addition to adjusting the valve setting of the valve 42 as described above, the controller 46 may also adjust a pump setting of the pump 44 associated with the internal fluid cooling loop 36 of the free cooling assembly 14, a compressor setting of the compressor 28 associated with the vapor compression loop 22 of the vapor compression assembly 12, a pump setting of the pump 19 associated with the process fluid loop 18, a fan setting of the fan 39 of the air cooled heat exchanger 38, or any combination thereof. Various performance and results data are illustrated in FIG. 6 and associated with the above-described conditions, including parameters associated with the compressor 28, the condenser 26, the evaporator 30, the air cooled heat exchanger 38 (or fan 39 thereof), the plate frame heat exchanger 40, the load 20, the valve 42, the pump 44, the pump 19, temperatures of various fluids, flow rates of various fluids, power consumption of various componentry, etc. Further, as shown in block 60, a total chiller kW/Ton with the illustrated conditions and control features is 0.008, substantially lower than the kW/Ton in FIGS. 2-5.

[0055] FIG. 7 is a schematic view of an embodiment of the HVAC&R system 10 in FIG. 1, where ambient temperature is 60 degrees Fahrenheit and an operating load is 50% of system design load capacity (e.g., as shown in legend 59). Further, a supply temperature of the process fluid 16 to the load 20 is 70 degrees Fahrenheit, and a return temperature of the process fluid 16 from the load 20 is 100 degrees Fahrenheit. Like described in 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 relies on the plate frame heat exchanger 40 of the free cooling assembly 14 for cooling the process fluid 16 of the process fluid loop 18, and does not rely on the evaporator 30 of the vapor compression assembly 12 for cooling the process fluid 16 of the process fluid loop 18. The illustrated controls rely on the free cooling assembly 14 (and not the vapor compression assembly 12, which includes the compressor 28 disconnected or otherwise turned off) as shown due to the relatively low ambient temperature (e.g., 60 degrees Fahrenheit) and operating load (e.g., 50% of system design load capacity).

[0056] In addition to adjusting the valve setting of the valve 42 as described above, the controller 46 may also adjust a pump setting of the pump 44 associated with the internal fluid cooling loop 36 of the free cooling assembly 14, a compressor setting of the compressor 28 associated with the vapor compression loop 22 of the vapor compression assembly 12, a pump setting of the pump 19 associated with the process fluid loop 18, a fan setting of the fan 39 of the air cooled heat exchanger 38, or any combination thereof. Various performance and results data are illustrated in FIG. 7 and associated with the above-described conditions, including parameters associated with the compressor 28, the condenser 26, the evaporator 30, the air cooled heat exchanger 38 (or fan 39 thereof), the plate frame heat exchanger 40, the load 20, the valve 42, the pump 44, the pump 19, temperatures of various fluids, flow rates of various fluids, power consumption of various componentry, etc. Further, as shown in block 60, a total chiller kW/Ton with the illustrated conditions and control features is 0.005.

[0057] It should be noted that, in both of FIGS. 6 and 7, the valve 42 is controlled (e g., via the controller 46) to a setting that blocks the cooling fluid 34 to 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 this correspondence in the flow of the cooling fluid 34 in FIGS. 6 and 7, the total chiller kW/Ton is lower in FIG. 7 than in FIG. 6. The lower total chiller kW/Ton in FIG. 7 than in FIG. 6 is based on the lower ambient temperature (e.g., 60 degrees in FIG. 7 and 65 degrees in FIG. 6) and corresponding controls of other features of the HVAC&R system 10. Indeed, because of the reduced ambient temperature, other componentry of the HVAC&R system 10 may be operated in a manner that reduces energy consumption, such as the fan 39 of the air cooled heat exchanger 38. For example, the fan 39 of the air cooled heat exchanger 38 in FIG. 6 is operated at 1.4 kW, whereas the fan 39 of the air cooled heat exchanger 38 in FIG. 7 is operated at 0.7 kW. In this way, the fan 39 may be a variable speed fan, for example, controlled to a setting based on a desired or target amount of cooling of the cooling fluid 34 by the fan 39.

[0058] In general, the HVAC&R system 10 in accordance with the present disclosure is configured to rely more heavily on the free cooling assembly 14 than the vapor compression assembly 12 relative to traditional embodiments, whether the HVAC&R system 10 is operated to rely on only the vapor compression assembly 12 for cooling the process fluid 16, only the free cooling assembly 14 for cooling the process fluid 16, or on both the vapor compression assembly 12 and the free cooling assembly 14 for cooling the process fluid 16.

[0059] FIG. 8 is a process flow diagram illustrating an embodiment of a method 100 of operating the HVAC&R system of FIG. 1. In the illustrated embodiment, the method 100 includes biasing (block 102), via a pump, a process fluid through a process fluid loop 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 Depending on ambient conditions, operating conditions of the HVAC&R system, and/or certain corresponding control features, a working fluid of the vapor compression assembly, a 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.

[0060] The method 100 also includes detecting (block 104), via a sensor (e.g., a temperature sensor), an ambient temperature. The sensor may be disposed, for example, adjacent an air cooled heat exchanger of the free cooling assembly. As will be appreciated in view of the description below, the ambient temperature detected by the sensor may be utilized to determine various control features associated with the HVAC&R system, such as control features employed to flow the cooling fluid of the free cooling assembly to a condenser of the vapor compression assembly (e.g., for removing heat from the working fluid of the vapor compression assembly), the plate frame heat exchanger of the free cooling assembly (e.g., for cooling the process fluid), or both.

[0061] The method 100 also includes controlling (block 106), via a controller and based at least on the ambient temperature and an operating load (or cooling demand) associated with the load, a valve setting of a valve of the free cooling assembly 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. Various control features associated with various ambient temperatures and/or operating loads are illustrated in FIGS. 2-7 and described in detail above. In general, when the ambient temperature and/or the operating load is relatively low, the system relies more heavily (or entirely) on the free cooling assembly than the vapor compression assembly. The valve setting of the valve may also be dependent at least in part on a supply temperature of the process fluid to the load (or a target supply temperature) and/or a return temperature of the process fluid from the load (or a target return temperature).

[0062] The method 100 also includes controlling (block 108), via the controller, other aspects of the HVAC&R system. For example, control of the other aspects of the HVAC&R system may be dependent at least in part on the above-described ambient conditions and/or operating conditions of the HVAC&R system. Additionally or alternatively, control of the other aspects of the HVAC&R system may be dependent on the valve setting of the valve. The aspects of the HVAC&R system that may be controlled in accordance with the above-referenced data may include a compressor setting of a compressor, a pump setting of a pump corresponding to the free cooling assembly, a pump setting of a pump corresponding to the process fluid loop, a fan setting of the air cooled heat exchanger of the free cooling assembly, and/or other aspects of the HVAC&R system. For example, when 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, the setting of the compressor may reduced when the system includes a relatively low reliance on the vapor compression assembly for cooling the process fluid. Further, the fan setting of the fan of the air cooled heat exchanger may be reduced when ambient temperatures and/or operating loads are relatively low. Based on these controls, the control of the valve setting of the valve, and other aspects of the presently disclosed HVAC&R system, sufficient cooling to the process fluid (and subsequently the load) may be provided while reducing energy consumption and reducing a refrigerant charge in the vapor compression assembly relative to traditional embodiments.

[0063] The features illustrated in, and described above with respect to, FIGS. 1-7 are examples of HVAC&R systems employing a vapor compression assembly and a free cooling assembly, in which the free cooling assembly is prioritized for energy savings and reduced refrigerant charge in the vapor compression assembly. The componentry illustrated in FIGS. 1-7 and described in detail above may enable the energy savings and the reduced refrigerant charge relative to traditional embodiments. However, FIGS. 1-7 and corresponding description are merely exemplary, and other componentry intended to enable the above-described technical effects and/or further improve energy savings and reduce refrigerant charge are also possible.

[0064] For example, FIG. 9 is a schematic view of an embodiment of a multitemperature hydronic HVAC&R system 210 employing a vapor compression assembly 212 (or chiller assembly), a free cooling assembly 214, and control features configured to modulate a reliance on the vapor compression assembly 212 and the free cooling assembly 214.

[0065] In general, the vapor compression assembly 212 and the free cooling assembly 214 are configured to cool a process fluid 216 (e.g., water, glycol, a water-glycol mixture, a dielectric fluid in liquid immersion applications, etc.) corresponding to a process fluid loop 218, where the process fluid 216 is biased through the process fluid loop 218 via one or more pumps 219a, 219b. As shown, the process fluid loop 218 may guide the process fluid 216 to one or more loads 220a, 220b. In the illustrated embodiment, the load 220a is a high temperature load and the load 220b is a low temperature load. Depending on ambient conditions and/or operating conditions of the HVAC&R system 210, a reliance on the vapor compression assembly 212 and/or a reliance on the free cooling assembly 214 for cooling the process fluid 216 may be modulated to ensure adequate cooling and reduce energy consumption of the HVAC&R system 210 relative to traditional embodiments. [0066] The vapor compression assembly 212 may include a vapor compression loop 222 (referred to in certain instances of the present disclosure as a working fluid loop) that 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 bias the working fluid 224 through the vapor compression loop 222 (e.g., by increasing a pressure of the working fluid 224) in certain conditions. The evaporator 230 may operate to cool the process fluid 216 of the process fluid loop 218 in certain conditions. The expansion valve 232 may operate to reduce a 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 certain conditions via fluid-to-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 considered a part of the internal fluid cooling loop 236 while the cooling fluid 234 of the internal fluid cooling loop 236 is present at the condenser 226.

[0067] In the illustrated embodiment, the vapor compression assembly 212 includes features configured to divert a flow path of some or all of the working fluid 224 in certain conditions. For example, valve 237 may be controlled (e.g., via a controller 246) based on certain ambient and/or operating conditions to cause a flow of the refrigerant 224 through a heat exchanger 235 corresponding to a heat recapture path 241 employing a heat recapture fluid 243 (e.g., water, glycol, or a water-glycol mixture). In this way, the heat recapture fluid 243 may extract heat from the working fluid 224 at the heat exchanger 235. The heat exchanger 235 may be a plate frame heat exchanger of a weld brazed heat exchanger. [0068] As previously described, in certain ambient conditions and/or operating conditions of the HVAC&R system 210, the free cooling assembly 214 may be employed to reduce a reliance on the vapor compression assembly 212 for cooling the process fluid 216 of the process fluid loop 218. For example, as a reliance on the free cooling assembly 214 is increased in response to certain conditions, a reliance on the compressor 228 of the vapor compression assembly 212 may be reduced. In certain conditions, the compressor 228 may be entirely disconnected or otherwise turned off while the HVAC&R system 210 relies only on the free cooling assembly 214 to provide cooling to the process fluid 216. Movement of the working fluid 224 through the vapor compression loop 222 may continue after the compressor 228 is disconnected or otherwise turned off via natural convection (e.g., via a thermo siphon). Additionally or alternatively, the HVAC&R system 210 may rely on both the free cooling assembly 214 and the vapor compression assembly 212 in certain conditions with the compressor 228 controlled to a relatively low setting, thereby improving energy efficiency while ensuring adequate cooling of the process fluid 216. Aspects of the free cooling assembly 214 and control of the HVAC&R system 210 to modulate reliance on the vapor compression assembly 212 and/or the free cooling assembly 214 are described in detail below.

[0069] In the illustrated embodiment, the free cooling assembly 214 includes the internal fluid cooling loop 236 configured to route the cooling fluid 234 through various components of the HVAC&R system 210, including the 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. In general, the air cooled heat exchanger 238 is configured to cool the cooling fluid 234 (e.g., via the fan 239) prior to delivery of the cooling fluid 234 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 one instance of the fan 239 configured to cool the cooing fluid 234 prior to delivery of the cooling fluid 234 to the condenser 226 and/or the plate frame heat exchanger 240. [0070] When the cooling fluid 234 is present at the condenser 226, the cooling fluid 234 absorbs heat from the working fluid 224 corresponding to the vapor compression assembly 212, causing the working fluid 224 to condenser prior to delivery of the working fluid 224 to the expansion valve 232. When the cooling fluid 234 is present at 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 may 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 described in detail below.

[0071] The free cooling assembly 214 includes a valve 242 controlled to various settings to direct portions of the cooling fluid 234 to the condenser 226 of the vapor compression assembly 212 and/or the plate frame heat exchanger 240 of the free cooling assembly 214. Further, the free cooling assembly 214 includes a pump 244 configured to bias the cooling fluid 234 through the internal fluid cooling loop 236. Depending on the ambient conditions and/or operating conditions of the HVAC&R system 210, the valve 242 may 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 a number of 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.

[0072] The controller 246 of the HVAC&R system 210, which includes processing circuitry 248 and memory circuitry 250, may be employed to control various of the above-described components. For example, the controller 246 may receive one or more inputs indicative of various ambient conditions and/or operating conditions of the HVAC&R system 210. Indeed, the controller 246 may receive, from a first sensor 252, a first input indicative of an ambient temperature (e.g., proximate the air cooled heat exchanger 238). Additionally or alternatively, the controller 246 may receive, from a second sensors 254a, 254b, second inputs indicative of a supply temperature of the process fluid 216 directed to the loads 220a, 220b. Additionally or alternatively, the controller 46 may receive, from third sensors 256a, 256b, third inputs indicative of a return temperature of the process fluid 216 returned from the loads 220a, 220b. In some embodiments, the controller 246 may employ target supply temperatures of the process fluid 216 directed to the loads 220a, 220b and/or target return temperatures of the process fluid 216 returned from the loads 220a, 220b (e.g., in addition to, or in the alternate of, the detected temperatures). Additionally or alternatively, the controller 246 may receive (or otherwise determine) fourth inputs indicative of operating loads corresponding to the HVAC&R system 210 and/or the loads 220a, 220b.

[0073] In response to at least one of the above-described inputs (e.g., the ambient temperature, the supply temperature and/or target supply temperature of the process fluid 216, the return temperature and/or target return temperature of the process fluid 216, the operating load), the controller 246 may control various components of the HVAC&R system 210 to ensure adequate cooling of the loads 220a, 220b while reducing energy consumption. In particular, the controller 246 may 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 some or all of the cooling fluid 234 to the plate frame heat exchanger 240.

[0074] Other aspects of the HVAC&R system 210 may also be controlled to correspond to the valve setting of the valve 242 (or based on the above-described inputs). For example, a setting of the compressor 228 and/or a setting of the fan 239 of the air cooled heat exchanger 238 may be controlled in a manner that provides adequate cooling to the process fluid 216 while reducing an energy consumption of the HVAC&R system 210 In general, presently disclosed systems and methods are configured to enable the HVAC&R system 210 to provide adequate cooling to the process fluid 216 while relying heavily on the free cooling assembly 214, thereby improving efficiency of the HVAC&R system 210 relative to traditional embodiments.

[0075] As previously described the HVAC&R system 210 includes the heat recapture path 241 configured to flow the heat recapture fluid 243 to the heat exchanger 235. The heat recapture fluid 243 may also be provided to an additional heat exchanger 260 upstream of the heat exchanger 235. The additional heat exchanger 260 may be employed to receive a portion of the process fluid 216 (e.g., to cool the process fluid 216).

[0076] As noted above, the HVAC&R system 210 employs the working fluid 224, the cooling fluid 234, the process fluid 216, and the heat recapture 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 bias the fifth fluid 264 through the fifth fluid loop 262. At 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 controlled (e.g., by the controller 246) to various fan settings based on a wet bulb temperature detected by a sensor 271, a required cooling capacity, and/or an availability of water, 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, a pump setting of the pump 268 may also be controlled based on the wet bulb temperature detected by the sensor 271 and/or other ambient conditions and/or operating conditions of the HVAC&R system 210.

[0077] The process fluid loop 218 in FIG. 9 also includes a series of flow-diverting valves 270a, 270b, 270c, 270d, 270e controlled to various settings to cause various flows of the process fluid 216 through various pathways of the process fluid loop 218. Further, the process fluid loop 218 includes a series of bypass valves 272a, 272b, 272c employed to open and close various paths in the process fluid loop 218. The controller 246 may control the flow-diverting valves 270a, 270b, 270c, 270d, 270e and the bypass valves 272a, 272b, 272c, 272d (e.g., based on ambient conditions, operating conditions of the HVAC&R system, etc.) to control the flow of the process fluid 216 through various componentry of the HVAC&R system 210 described in detail above. An example of a multi-temperature hydronic HVAC&R system with flow control features can be found in PCT/US22/19819, entitled “MULTI-STAGE THERMAL MANAGEMENT SYSTEMS AND METHODS,” filed March 20, 2022, which is hereby incorporated by reference in its entirety.

[0078] In general, presently disclosed systems and methods are configured to provide adequate cooling to one or more loads associated with an HVAC&R system, while improving energy efficiency over traditional embodiments, reducing refrigerant charge for vapor compression over traditional embodiments, and the like.

[0079] While only certain features of present embodiments have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes that fall within the true spirit of the disclosure. Further, it should be understood that certain elements of the disclosed embodiments may be combined or exchanged with one another.

[0080] The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function], ..” or “step for [perform]ing [a function]...”, it is intended that such elements are to be interpreted under 35 U.S.C. 1 12(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).