Multi-temperature hydronic system and method with controls and fluid management

Abstract

A multi-temperature hydronic system (MTHS) (10) comprises a plurality of heat rejection devices including at least two of an evaporative fluid cooler (28), a dry cooler (30), or a heat recovery heat exchanger (32). The MTHS (10) also includes an MTHS skid (11) having a plurality of valves (50, 52, 54, 58, 60, 61, 62, 64, 66, 74, 76, and / or 78) controllable to adjust fluid flows of a fluid between the plurality of heat rejection devices, a chiller oil cooler (16a), and a chiller condenser (14a). The MTHS (10) also includes a controller (34) configured to control the plurality of valves (50, 52, 54, 58, 60, 61, 62, 64, 66, 74, 76, and / or 78) to selectively engage at least one heat rejection device of the plurality of heat rejection devices to achieve a target temperature of the fluid at the chiller oil cooler (16a), and to optimize a temperature of the fluid at the chiller condenser (14a). Other features may include a spray water circuit (175) of the evaporative fluid cooler (28) and control features related to the evaporative fluid cooler (28) and configured to, among other things, periodically replace water in the spray water circuit (175).

Description

MULTI-TEMPERATURE HYDRONIC SYSTEM AND METHOD WITH CONTROLS AND FLUID MANAGEMENTCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application Serial No. 63 / 690,178, entitled “MULTI-TEMPERATURE HYDRONIC SYSTEM AND METHOD WITH CONTROLS AND FLUID MANAGEMENT,” filed September 3, 2024, which is incorporated herein 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 and / or claimed 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] Heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) systems typically operate to control a temperature of a thermal load (e.g.. a fluid, device, structure, or space serviced by the HVAC&R system) via circulation of at least one heat transfer fluid (e.g., water, brine, refrigerant, air, etc.) between and / or across various heat exchange equipment of the HVAC&R system. For example, the HVAC&R system generally includes a compressor or pump configured to circulate a flow of a heat transfer fluid along a series of conduits (e.g.. pipes) and between heat exchangers of the HVAC&R system. The heat exchangers facilitate transfer of thermal energy between the thermal load, the heat transfer fluid, and a receiving load (e.g., an ambient environment surrounding the HVAC&R system). As such, the HVAC&R system facilitates transfer of thermal energy to (or extraction of thermal energy from) the thermal load via circulation of the heat transfer fluid through the conduits and between the heat exchangers. In this way, the HVAC&R system may be used to facilitate temperature control of the thermal load. Unfortunately, existing HVAC&R systems may be ill-equipped to facilitate efficienttemperature regulation of multiple thermal loads. Accordingly, it is now recognized that improved systems and methods are desired.SUMMARY

[0004] 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.

[0005] In an embodiment, a multi-temperature hydronic system (MTHS) comprises a plurality' of heat rejection devices including an evaporative fluid cooler, a dry cooler, and a heat recovery’ heat exchanger. The MTHS also includes an MTHS skid having a plurality of valves controllable to adjust fluid flows of a fluid between the plurality of heat rejection devices, a chiller oil cooler, and a chiller condenser. The MTHS also includes a controller configured to control the plurality' of valves to selectively engage at least one heat rejection device of the plurality of heat rejection devices to achieve a target temperature of the fluid at the chiller oil cooler, or to optimize a temperature of the fluid at the chiller condenser. Other features may include a spray water circuit of the evaporative fluid cooler and control features configured to, for example, periodically replace water in the spray water circuit.

[0006] In an embodiment, a multi-temperature hydronic system (MTHS) includes a plurality of heat rejection devices including an evaporative fluid cooler and at least one additional heat rejection device, an MTHS skid including a plurality of valves controllable to adjust fluid flows of a fluid between the plurality of heat rejection devices and a chiller oil cooler, a chiller condenser, or both, and a spray water circuit of the evaporative fluid cooler. The spray water circuit includes a reservoir configured to collect water, a sprayer assembly configured to spray the water onto a portion of the evaporative fluid cooler, a pump configured to bias the water from the reservoir to the sprayer assembly, a drain valve configured to drain the water from the reservoir, and a make-up valve.

[0007] In an embodiment, a method of operating a multi-temperature hydronic system(MTHS) includes adjusting, via a controller and based on a target temperature of a fluid at a chiller oil cooler, a temperature of the fluid at a chiller condenser, or both, at least onevalve of a plurality of valves corresponding to a skid of the MTHS to selectively engage at least one heat rejection device of a plurality of heat rejection devices of the MTHS by adjusting at least one fluid flow of the fluid between the plurality of heat rejection devices and the chiller oil cooler, the chiller condenser, or both.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which:

[0009] FIG. 1 is a schematic illustration of an embodiment of a multi-temperature hydronic system (MTHS), in accordance with an aspect of the present disclosure;

[0010] FIG. 2 is a schematic illustration of an embodiment of a portion of a multitemperature hydronic system (MTHS) including an MTHS skid and detailed fluid management control features (e.g., valves) thereof, in accordance with an aspect of the present disclosure;

[0011] FIG. 3 is a perspective view of an embodiment of a chiller employed in or interfacing with a multi-temperature hydronic system (MTHS), in accordance with an aspect of the present disclosure;

[0012] FIG. 4 is a detailed schematic diagram of an embodiment of a multitemperature hydronic system (MTHS), in accordance with an aspect of the present disclosure; and

[0013] FIG. 5 is a process flow diagram illustrating an embodiment of a method of operating a multi-temperature hydronic system (MTHS), in accordance with an aspect of the present disclosure.DETAILED DESCRIPTION

[0014] One or more specific embodiments will be described below. In 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 thedevelopers' 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.

[0015] 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 noted 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.

[0016] As used herein, the terms “approximately,” “generally.” “substantially,” and so forth, are intended to convey that the property value being described may be within a relatively small range of the property value, as those of ordinary' skill would understand. For example, when a property value is described as being “approximately” equal to (or, for example, “substantially similar” to) a given value, this is intended to convey that the property value may be within + / - 5%, within + / - 4%, within + / - 3%, within + / - 2%, within + / - 1%, or even closer, of the given value. Similarly, when a given feature is described as being “substantially parallel” to another feature, “generally perpendicular” to another feature, and so forth, this is intended to convey that the given feature is within + / - 5%. within + / - 4%. within + / - 3%. within + / - 2%. within + / - 1%. or even closer, to having the described nature, such as being parallel to another feature, being perpendicular to another feature, and so forth. Mathematical terms, such as “parallel” and “perpendicular,” should not be rigidly interpreted in a strict mathematical sense, but should instead be interpreted as one of ordinary skill in the art would interpret such terms. For example, one of ordinary skill in the art would understand that tw o lines that are substantially parallel to each other are parallel to a substantial degree, but may have minor deviation from exactly parallel.

[0017] As briefly discussed above, a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system may be used to thermally regulate a thermal load that is serviced by the HVAC&R system. The thermal load may include a space within abuilding, home, or other suitable structure (e.g., a data center), a device (e.g., an electronic device, an electromechanical device), and / or another suitable space, component, or assembly for which temperature regulation is desired. The HVAC&R system may facilitate temperature regulation of the thermal load via circulation of at least one heat transfer fluid between various heat exchange equipment of the HVAC&R system. For example, in some cases, the HVAC&R system may include a vapor compression system (e.g., a chiller system) that transfers thermal energy between the heat transfer fluid (e.g., a refrigerant) and a fluid to be conditioned, such as air, water, or brine. A compressor or pump may be used to direct the fluid to be conditioned to a heat exchanger that is in thermal communication with the thermal load. The heat exchanger may enable transfer of thermal energy between the thermal load and the fluid to be conditioned and, thus, facilitate temperature regulation of the thermal load.

[0018] In some embodiments, a facility (e g., a data center, a manufacturing or processing plant, etc.) may include a plurality of thermal loads corresponding to various devices, processes, and / or sub-systems (e.g., immersion tanks) of the facility for which thermal regulation is desired. The thermal loads may each have a cooling demand that corresponds to an operating capacity (e.g., a current operating capacity) of the thermal loads. As such, cooling demands between various thermal loads may vary based on the relative operating capacities of the thermal loads during a given time period. For example, in some embodiments, a cooling demand of a particular thermal load may increase as the operating capacity of the thermal load increases. Conversely, the cooling demand of the thermal load may decrease as the operating capacity of the thermal load decreases. Further, target temperature set-points for certain of the thermal loads may be the same as or different from other thermal loads in a system. As an example, target temperature set-points corresponding to a first subset of the thermal loads may be set at a first value that is greater than or less than target temperature setpoints corresponding to a second subset of the thermal loads. As such, an overall cooling demand of the facility may, in some cases, correspond to a sum of the individual cooling demands of the thermal loads, where the thermal loads may include the same or unique target temperature set-points relative to one another. A cooling demand of each thermal load may correspond to the particular target temperature set-point of that thermal load.

[0019] Conventional HVAC&R systems may be ill-equipped to enable independent, efficient, temperature regulation of multiple thermal loads based on the operating capacities of the thermal loads and / or based on the target temperature setpoints corresponding to the thermal loads. As a result, typical HVAC&R systems may be prone to over-cooling a heat transfer fluid intended for supply to certain thermal loads and / or inadequately cooling the heat transfer fluid intended for supply to other thermal loads. Moreover, conventional HVAC&R systems may be unable to adjust operation of the heat exchange equipment of the HVAC&R system based on the current cooling demands of the thermal loads, as well as based on efficiency parameters that may affect the relative operating costs and / or operating efficiencies the heat exchange equipment. As an example, the efficiency parameters affecting the relative operational efficiencies of the heat exchange equipment may include water costs, electricity costs, a temperature of an ambient environment surrounding the HVAC&R system (e.g., dry bulb temperature, wet bulb temperature), a humidity level of the ambient environment surrounding the HVAC&R system, a capacity loading of the heat exchange equipment, and / or other relevant parameters.

[0020] It is presently recognized that enabling independent temperature regulation of the thermal loads of a facility or other system may facilitate increased efficiency of an HVAC&R system utilized to condition the thermal loads. For example, temperature regulation of the thermal loads based on the individual cooling demands (e.g., operating capacities) of the thermal loads and in accordance with the target temperature set-points corresponding to the thermal loads (e.g., which may be indicative of at least a portion of the cooling demands) may enable a reduction in costs associated with operating the HVAC&R system along with an increased ability to recover useful heat energy. Further, it is presently recognized that coordinating operation of the heat exchange equipment of the HVAC&R system based on one or more monitored efficiency parameters, including but not limited to operating conditions, ambient conditions, load conditions, one or more set points, other conditions, or any combination thereof, may increase an overall operational efficiency of the HVAC&R system.

[0021] Accordingly, embodiments of the present disclosure are directed to a multitemperature hydronic system (MTHS) that is configured to facilitate independent temperature regulation of each of multiple thermal loads, or subsets of the thermalsloads, as well as to adjust operation of heat exchange equipment based on monitored efficiency parameters. For example, as discussed in detail below with reference to later drawings, the MTHS may include an MTHS skid with various valves controllable to engage certain heat rejection devices and / or disengage certain heat rejection devices for temperature control of the heat transfer fluid (e.g., such that a first temperature of the heat transfer fluid delivered to one or more chiller oil coolers is substantially the same as or similar to a target temperature, such that a second temperature of the heat transfer fluid delivered to one or more chiller condensers is reduced or otherwise sufficiently low, etc.), to improve an efficiency of the system, or both. A control system of the MTHS is configured to control the above-described valves and / or pumps to obtain such temperature conditions of the heat transfer fluid and overall efficiency based, for example, on the above-described efficiency parameters (e.g., water costs, electricity costs, temperature conditions of an ambient environment surrounding the HVAC&R system, including dry' bulb temperature and wet bulb temperature, a humidity7level of the ambient environment surrounding the HVAC&R system, a capacity7loading of the heat exchange equipment, and / or other relevant parameters). Additional features of the present disclosure may include a spray water circuit of an evaporative fluid cooler of the MTHS, and control features related to the evaporative fluid cooler and configured to, among other things, periodically replace water in the spray water circuit, combat freezing conditions, etc. These and other features will be described in detail below with reference to the drawings.

[0022] Turning now to the drawings, FIG. 1 is a schematic illustration of an embodiment of a multi-temperature hydronic system (MTHS) 10. As shown, the MTHS 10 may include an MTHS skid 11 and a number of chillers 12a, 12b, 12c, 12n. In some embodiments, the chillers 12a, 12b, 12c, 12n may be considered separate from the MTHS 10 and interfaced with the MTHS 10 (e.g., via the MTHS skid 11). Other aspects of certain embodiments of the MTHS skid 11 will be described in greater detail with reference to FIG. 2. The first chiller 12a illustrated in FIG. 1 may include a condenser 14a and an oil cooler 16a. Further, it should be understood that the other chillers 12b, 12c, 12n also may include their own instances of such componentry7(e.g., the second chiller 12b includes a second condenser and a second oil cooler, the third chiller 12c includes a third condenser and a third oil cooler, and so on and so forth).While the illustrated embodiment illustrates the chillers 12a, 12b, 12c, 12n, it should be noted that fewer or more chillers may be employed in other embodiments.

[0023] As shown, a first distribution assembly 18 of the MTHS 10 may be employed to distribute a heat transfer fluid, such as glycol, from the MTHS skid 11 to the condensers of the chillers 12a, 12b, 12c, 12n (e.g., the condenser 14a of the first chiller 12a), and to return the heat transfer fluid from the condensers of the chillers 12a, 12b, 12c, 12n (e.g., the condenser 14a of the first chiller 12a) to the MTHS skid 1 1. The heat transfer fluid may be referred to below as the fluid for purposes of brevity7. A first pump 20 may be employed to bias the fluid through the first distribution assembly 18. In some embodiments, valves 21a, 21b. 21c, 21n of the first distribution assembly 18 also may be employed to control a flow7of the fluid to the chillers 12a, 12b, 12c, 12n. Further, a second distribution assembly 22 may be employed to distribute the fluid from the MTHS skid 11 to the oil coolers of the chillers 12a, 12b, 12c, 12n (e.g., the oil cooler 16a of the first chiller 12a), and to return the fluid from the oil coolers of the chillers 12a, 12b, 12c, 12n to the MTHS skid 11. A second pump 24 may be employed to bias the fluid, such as the glycol, through the second distribution assembly 22. In some embodiments, valves 23a, 23b, 23c, 23n of the second distribution assembly 22 also may be employed to control a flow of the fluid to the oil coolers 16a, 16b, 16c, 16n.

[0024] As shown, separation of the fluid corresponding to the first distribution assembly 18 and the fluid corresponding to the second distribution assembly 22 may be maintained in at least certain portions of the MTHS 10. For example, a first glycol loop corresponding to the first distribution assembly 18 betw een the MTHS skid 11 and the chillers 12a, 12b, 12c, 12n may be employed and a second glycol loop corresponding to the second distribution assembly 22 between the MTHS skid 11 and the oil coolers 16a, 16b. 16c, 16n may be employed. In this way. and as described in greater detail below, a first temperature of the fluid in the first distribution assembly 18 and a second temperature of the fluid in the second distribution assembly 22, where the first temperature is different than the second temperature, may be obtained in accordance with present embodiments. In this way. various target temperature conditions may be obtained in the fluid at the first distribution assembly 18 and / or at the second distribution assembly 22. However, it should be understood that the fluid may becomingled in other areas of the MTHS 10 in certain embodiments, such as in the MTHS skid 11 and at various heat rejection devices and / or tanks described in greater detail below.

[0025] Selective heat rejection, recapture, and / or reclaiming features may be employed in accordance with the present disclosure. As shown, for example, the MTHS skid 11 may be fluidly coupled with an expansion tank 26, an evaporative fluid cooler 28, a dry cooler 30, and / or a heat recovery heat exchanger 32. Depending on one or more efficiency parameters, such as operating conditions, ambient conditions (e.g., temperatures, such as dry bulb temperature and / or wet bulb temperature), load conditions, and / or setpoints, among other possible efficiency parameters, the MTHS 10 may be controlled to selectively bias the fluid (e.g., glycol) toward the expansion tank 26, the evaporative fluid cooler 28, the dry' cooler 30, and / or the heat recovery' heat exchanger 32. In general, the expansion tank 26 may be employed to accommodate changes in liquid volume as liquid temperature changes, whereas the evaporative fluid cooler 28, the dry cooler 30, and / or the heat recovery heat exchanger 32 may be selectively employed as heat rejection devices.

[0026] A controller 34 (or control assembly) may be employed to control certain of the componentry described above and / or certain other componentry. The controller 34 may include processing circuitry' 36 and memory circuitry' 38, the memory circuitry' 38 storing instructions thereon that, when executed by the processing circuitry' 36, cause the processing circuitry 36 to perform various functions. The memory circuitry 38 may include one or more memories, such as volatile memory' (e.g., random-access memory or RAM) and / or non-volatile memory, such as read-only memory^ (ROM), optical drives, hard disc drives, solid-state drives, or any other non-transitory computer- readable medium that includes instructions (e.g., processor input instructions) to perform various functions, or any combination thereof. The processing circuitry 36 may include one or more application specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more general purpose processors, or the like, or any combination thereof. It should be noted that “the controller 34,"’ as described herein, may include one or more controllers in certain embodiments.

[0027] In general, the controller 34 may receive one or more inputs 40 (e.g., indicative of one or more efficiency parameters, such as operating conditions, ambientconditions, load conditions, one or more set points, other conditions, etc.). Based on the one or more inputs 40, the controller 34 may control various aspects of the MTHS 10 (e.g., the pumps 20, 24, the valves 21a, 21b, 21c, 2 In associated with the first distribution assembly 18, the valves 23a, 23b, 23c, 23n associated with the second distribution assembly 22, fans, and / or additional componentry of the MTHS skid 11, such as additional valves, described in greater detail with reference later drawings) to direct, change, block, or otherwise control fluid flows through the MTHS 10. Additionally or alternatively, as described in greater detail with reference to FIG. 4, the controller 34 may control various aspects of the MTHS 10 related to a water circuit employed, for example, at the evaporative fluid cooler 28. As described in greater detail with reference to later drawings, the controller 34 may control such componentry in order to lower a temperature (or otherwise maintain a sufficiently low temperature) of the fluid flowing to the condensers of the chillers 12a, 12b, 12c, 12n (e.g., the condenser 14a of the first chiller 12a), and to achieve a target temperature (e.g., based on a set point) of the fluid flowing to the oil coolers of the chillers 12a, 12b, 12c, 12n (e.g., the first oil cooler 16a of the first chiller 12a). For example, the controller 34 may operate to maintain the temperature of the fluid at the condenser 14a above a threshold temperature (e.g., to avoid condensing below a minimum allowable temperature) but otherwise ensure that the temperature is relatively low. Additionally or alternatively, the controller 34 may operate to maintain a higher target temperature of the fluid at the oil cooler 16a (e.g., via a set point). These and other aspects are described in detail below with reference to later drawings.

[0028] FIG. 2 is a schematic illustration of an embodiment of a portion of an MTHS, such as the MTHS 10 in FIG. 1, including the MTHS skid 11 and various detailed fluid management control features (e.g., valves) of the MTHS skid 11. The detailed fluid management control features (e.g., valves) of the MTHS skid 11 may be controlled to, among other features, selectively engage and disengage various heat rejection devices of the MTHS 10, including the heat recovery heat exchanger 32, the dry cooler 30, and the evaporative fluid cooler 28. The controller 34 may determine and / or control selective engagement and disengagement of the various heat rejection devices in order to ensure a target temperature (e.g., based on a setpoint) of the fluid to the one or more oil coolers of the one or more chillers illustrated in FIG. 1, to ensure an adequately low temperature of the fluid to the one or more condensers of the one ormore chillers illustrated in FIG. 1, and / or to optimize an efficiency of the MTHS 10. In some embodiments, control schemes implemented by the controller 34 follow a heat rejection hierarchy based at least on the above-described considerations (e.g., efficiency considerations) and other possible conditions, in which the heat recovery heat exchanger 32 is the most preferred heat rejection device (e.g., where the dry cooler 30 is the next most preferred heat rejection device and the evaporative fluid cooler 28 is the least preferred heat rejection device, or vice versa, depending at least in part on various efficiency parameters or other conditions).

[0029] In the illustrated embodiment, the MTHS skid 11 may include an evaporative fluid cooler inlet valve 50 (e.g.. on / off valve, flow control valve, etc.) configured to control a fluid of the fluid (e.g., the glycol) to the evaporative fluid cooler 28, a dry cooler inlet valve 52 (e.g., on / off valve, flow control valve, etc.) configured to control a flow of the fluid to the dry cooler 30, and a heat recovery heat exchanger inlet valve 54 (e.g., on / off valve, flow control valve, etc.) configured to control a flow of the fluid to the heat recovery heat exchanger 32. For example, the evaporative fluid cooler inlet valve 50 may be opened to enable the flow of the fluid to the evaporative fluid cooler 28 and closed to block the flow of the fluid to the evaporative fluid cooler 28, the dry cooler inlet valve 52 may be opened to enable the flow of the fluid to the dry cooler 30 and closed to block the flow of the fluid to the dry cooler 30, and the heat recovery heat exchanger inlet valve 54 may be opened to enable the flow of the fluid to the heat recovery heat exchanger 32 and closed to block the flow of the fluid to the heat recovery heat exchanger 32. In general, as previously described, the various inlet valves 50, 52. 54 may be controllable (e.g., via the controller 34) based on one or more efficiency parameters, such as operating conditions, ambient conditions (e.g., temperatures, such as dry bulb temperature and / or wet bulb temperature), load conditions, one or more set points, and / other conditions to satisfy conditioning (e.g., cooling) demands associated with the MTHS 10 and to optimize efficiency of the MTHS 10 in satisfying such conditioning (e.g., cooling) demands.

[0030] The MTHS skid 11 also may include an evaporative fluid cooler bypass valve 56, a dry cooler bypass valve 58, and aheat recovery heat exchanger bypass valve 60. In general, the evaporative fluid cooler inlet valve 50 and the evaporative fluid cooler bypass valve 56 may be operated as a first pair, the dry cooler inlet valve 52 andthe dry cooler bypass valve 58 may be operated as a second pair, and / or the heat recovery heat exchanger inlet valve 54 and the heat recovery heat exchanger bypass valve 60 may be operated as a third pair. For example, the evaporative fluid cooler inlet valve 50 may be opened and the evaporative fluid cooler bypass valve 56 may be closed in an operating mode, and the evaporative fluid cooler inlet valve 50 may be closed and the evaporative fluid cooler bypass valve 56 may be opened in an additional operating mode. Likewise, the dry cooler inlet valve 52 may be opened and the dry cooler bypass valve 58 may be closed in an operating mode, and the dry cooler inlet valve 52 may be closed and the dry7cooler bypass valve 58 may be opened in an additional operating mode. Likewise, the heat recovery heat exchanger inlet valve 54 may be opened and the heat recovery heat exchanger bypass valve 60 may be closed in an operating mode, and the heat recovery heat exchanger inlet valve 54 may be closed and the heat recovery heat exchanger bypass valve 60 may be opened in an additional operating mode. As previously described, the controller 34 may open and / or close various ones of the valves 50, 52. 54, 56, 58, 60 based on efficiency parameters (e.g.. operating conditions, ambient conditions, load conditions, setpoints, etc.) to ensure an adequately low temperature of the fluid biased to the one or more condensers of the one or more chillers illustrated in FIG. 1, to achieve at least one target temperature (e.g., based on at least one set point) of the fluid biased to the one or more oil coolers of the one or more chillers illustrated in FIG. 1, and / or to meet various efficiency criteria (e.g., to optimize efficiency of the MTHS 10 while still meeting desired temperature conditions of the fluid at the one or more oil coolers and / or the one or more condensers).

[0031] The MTHS 11 in the illustrated embodiment also may include a first fluid injection valve 61, a second fluid injection valve 62, a third fluid injection valve 64, and a fourth fluid injection valve 66 configured to control (e.g., enable or block) a flow of the fluid from the first distribution assembly 18 (e.g., from the one or more condensers of the one or more chillers in FIG. 1) toward various locations of the MTHS skid 11, such as a header 68 and / or a location just upstream of the header 68. In the illustrated embodiment, for example, the three bypass valves 56, 58, 60 are disposed in the header 68, which runs adjacent to the heat rejection devices. The first fluid injection valve 61. when opened, may enable a flow of the fluid (e.g., from the one or more condensers of the one or more chillers in FIG. 1) to a first location just upstream of the header 68. Further, the second fluid injection valve 62, when opened, may enable aflow of the fluid (e.g., from the one or more condensers of the one or more chillers in FIG. 1) to the header 68 at a second location between the dry cooler 30 and the heat recovery heat exchanger 32. Further still, the third fluid injection valve 64, when opened, may enable a flow of the fluid (e.g., from the one or more condensers of the one or more chillers in FIG. 1) to the header 68 at a third location between the evaporative fluid cooler 28 and the dry cooler 30. Further still, the fourth fluid injection valve 66. when opened, may enable a flow of the fluid (e.g.. from the one or more condensers of the one or more chillers in FIG. 1) to the header 68 at a fourth location between the evaporative fluid cooler 28 and the dry cooler 30. It should be noted that, in certain embodiments, more than four or less than four fluid injection valves may be employed. The fluid injection valves 61. 62. 64. 66. along with the above-described first, second, third, and fourth locations, will be described in greater detail with reference to later drawings. In general, control of the fluid injection valves 61, 62, 64, 66 may be coordinated to distribute the fluid to various locations of the MTHS skid 11 in order to optimize an efficiency of the MTHS 10 and / or ensure desirable temperatures of the fluid at various locations (e.g.. a temperature of the fluid distributed to the one or more condensers of the one or more chillers in FIG. 1, a temperature of the fluid distributed to the one or more oil coolers of the one or more chillers in FIG. 1, etc.).

[0032] Further, first, second, and third control valves 74, 76, 78 (e.g., three-way valves) in the illustrated embodiment may be selectively controlled to control amounts, temperatures, and / or flow rates of the fluid through various portions of the MTHS skid 11. For example, the control valves 74, 76, 78 may be controlled to selectively blend two or more incoming fluid flows to control, for example, a temperature of fluid outflow from said control valves 74, 76, 78. As shown, the first control valve 74 may be selectively controlled to blend incoming flows of the fluid from a flow branch extending from an outlet of the header 68 and from a flow branch coupled to the header 68 between the evaporative fluid cooler 28 and the dry cooler 30. Further, the second control valve 76 may be selectively controlled to blend incoming flows of the fluid from the first control valve 74 and the first distribution assembly 18 (e.g., the one or more condensers of the one or more chillers in FIG. 1). Further still, the third control valve 78 may be selectively controlled to blend incoming flows of the fluid from the second control valve 76 and a flow branch coupled to the header 68 between the dry cooler 30 and the heat recoveiy heat exchanger 32. It should be noted that more than three or fewer thanthree control valves may be employed in other embodiments. Additional features associated with the control valves 74, 76, 78 in the illustrated embodiment, and related features (e.g., the flow branches described above) are illustrated in and will be described with respect to FIG. 4. In general, as previously described, the controller 34 may control settings of the fluid injection valves 61, 62, 64, 66 and / or the control valves 74, 76, 78 based on the aforementioned efficiency parameters and other possible considerations to optimize an efficiency of the MTHS 10 while ensuring desirable temperatures of the fluid (e.g., at the one or more condensers of the one or more chillers in FIG. 1, at the one or more oil coolers of the one or more chillers in FIG. 1, etc.). Additional and / or alternate control schemes and / or valve arrangements are also possible in accordance with the present disclosure.

[0033] Before continuing with another embodiment of the MTHS 10 in FIG. 4 illustrating additional and / or alternate control features. FIG. 3 is a perspective view illustrating an example of a chiller, such as the first chiller 12a illustrated in FIG. 1, which may also be included in certain embodiments of the MTHS 10 in FIG. 2 and / or the MTHS 10 in FIG. 4. As shown, the first chiller 12a includes an evaporator 100a, a compressor 102a, the condenser 14a, the oil cooler 16a, and a surge drum 104a. As previously described, the first distribution assembly 18 may be configured to direct the fluid (e.g., glycol) to and from the condenser 14a. the second distnbution assembly 22 may be configured to direct the fluid (e.g., glycol) to and from the oil cooler 16a, and the first and second distribution assemblies 18, 22 may be fluidly separate.

[0034] FIG. 4 is a schematic diagram of an embodiment of an MTHS, such as the MTHS 10 of FIG. 1. In the illustrated embodiment, the MTHS 10 may include various componentry7previously described with respect to FIGS. 1-3. For example, the MTHS 10 in FIG. 4 includes the expansion tank 26, the fluid cooler 28, the dry cooler 30, and the heat recovery heat exchanger 32 (e.g., heat reclaim heat exchanger). Further, the MTHS 10 in FIG. 4 may include the MTHS skid 11 and certain corresponding controls and valve componentry', such as the various inlet valves 50, 52, 54 to the heat rejection devices, the bypass valves 56, 58, 60 corresponding to the heat rejection devices, the fluid injection valves 61. 62. 64. 66. and the control valves 74, 76, 78. More detailed aspects of these components and additional (e.g., related) components are described below.

[0035] In the illustrated embodiment, the third control valve 78 may be selectively controlled in at least one operating mode to blend two incoming fluid flows, including a flow of the fluid from the second control valve 76 and a flow of the fluid from a bypass branch 152 (e.g., flow branch) coupled to the header 68 at a location 154 between the heat recovery heat exchanger 32 and the dry cooler 30. In certain operating conditions, the third control valve 78 may be controlled to enable the flow therethrough from the bypass branch 152, disable the flow therethrough from the bypass branch 152. enable the flow from the second control valve 76, disable the flow from the second control valve 76, and / or provide a mix of flows from these two locations. The fluid may be output from the third control valve 78 toward the pump 24 corresponding to the second distribution assembly 22. as shown. The third control valve 78 may be controlled (e.g., by the controller 34) at least in part to obtain a target temperature of the fluid, such as 115 degrees Fahrenheit or approximately 46 degrees Celsius as the fluid enters the oil cooler 16a of the chiller 12a, or such as 125 degrees Fahrenheit or approximately 52 degrees Celius as the fluid exits the oil cooler 16a of the chiller 12a.

[0036] As shown, the fourth fluid injection valve 66 (e.g., when opened) may be configured to output a flow of the fluid to the header 68 at a location 158 between the dry cooler 30 and the evaporative fluid cooler 28. Further, a bypass branch 160 (e.g., conduit, fluid return line, flow branch, etc.) may be coupled to the header 68 at a location 162 between the location 158 corresponding to the fluid output from the fourth fluid injection valve 66 and a location 164 corresponding to the fluid output from the third fluid injection valve 64 (e.g., when opened), where the bypass branch 160 (e.g., fluid return line) is configured to direct a portion of the fluid toward the first control valve 74 in at least some operating modes of the MTHS 10 (e.g., based on a setting of the first control valve 74). The first control valve 74 may also receive a portion of the fluid from flow branch 80 in at least some operating modes. In the illustrated embodiment, the flow branch 80 may extend from a location 166 of an outlet conduit 168 coupled to the header 68 (e.g., where the outlet conduit 168 extends between the header 68 and the pump 20). In this way, the first control valve 74 may be controllable to blend portions of the fluid from the flow branches 80, 160 in certain operating modes. For example, the first control valve 74 may be controllable to a variety of settings to change a flow rate (e.g.. to a target flow rate) or flow amount (e.g., to a target flow amount) of the fluids received via the flow branches 80, 160. Additionally oralternatively, the first control valve 74 may be controlled to enable the flow therethrough from the flow branch 80, disable the flow therethrough from the flow branch 80, enable the flow therethrough from the flow branch 160, and disable the flow therethrough from the flow branch 160 (e.g., depending on the operating mode and / or controls scheme).

[0037] Additionally or alternatively, the second control valve 76 may be controllable to a variety of settings to change a flow rate (e.g., to a target flow rate) or flow amount (e.g., to a target flow amount) of the fluids received from the first control valve 74 and / or from the condenser 14a. For example, the second control valve 76 may be controlled (e.g., via the controller 34) to blend such portions of the fluid. Additionally or alternatively, the second control valve 76 may be controlled to enable the flow therethrough from the first control valve 74, disable the flow therethrough from the first control valve 74, enable the flow therethrough from the condenser 14a, and disable the flow therethrough from the condenser 14a (e.g., depending on the operating mode and / or controls scheme). The third control valve 78, as previously described, may be configured to control (e.g., blend) flows of the fluid from the second control valve 76 and from the bypass branch 152 (e.g., flow branch).

[0038] Settings of the various valves, pumps, etc. in FIG. 4 may be controlled by the controller 34, for example, based on a dry bulb temperature, a wet bulb temperature, and / or a setpoint (e.g., the target temperature of the fluid entering the oil cooler 16a or the fluid leaving the oil cooler 16a), among other possible inputs (e.g., sensor feedback) to the controller 34. As a non-limiting example, legend 169 in the illustrated embodiment indicates that the dry bulb temperature is 73 degrees Fahrenheit (approximately 23 degrees Celsius), the wet bulb temperature is 63 degrees Fahrenheit (approximately 17 degrees Celsius), and the setpoint (e.g., the target temperature of the fluid entering the oil cooler 16a) is 115 degrees Fahrenheit (approximately 46 degrees Celius). Based at least in part on the dry bulb temperature and / or the wet bulb temperature illustrated in the legend 169 of FIG. 4, among other possible ambient and / or conditions, 90% or more of the load generated by the system may be attributable to the condenser 14a, and 10% or less of the load generated by the system may be attributable to the oil cooler 16a. However, other loads may occur based on other ambient and / or operation conditions. For example, the load generated by the systemmay be 0% to 100% attributable to the oil cooler 16a and / or 0% to 100% attributable to the condenser 14a depending on various conditions.

[0039] Based on the inputs from the legend 169 illustrated in FIG. 4 and / or the load distribution indicated in the pie chart 200. among other possible inputs, the controller 34 may implement the following controls: the evaporative fluid cooler inlet valve 50 may be opened, the dry cooler inlet valve 52 may be opened, the heat recovery heat exchanger inlet valve 54 may be opened, the evaporative fluid cooler bypass valve 56 may be closed, the dry' cooler bypass valve 58 may be closed, the heat recovery' heat exchanger bypass valve 60 may be closed, the first fluid injection valve 61 may be closed, the second fluid injection valve 62 may be opened, the third fluid injection valve 64 may' be closed, the fourth fluid injection valve 66 may be closed, port A of the first control valve 74 may be closed, port B of the first control valve 74 may be closed, port C of the second control valve 76 may be closed, port D of the second control valve 76 may be opened, port E of the third control valve 78 may be opened (, and / or port F of the third control valve 78 may be opened. Any port in an open position, such as ports D and E in the illustrated embodiment, may be modulated between various open positions in order to control properties of the fluid, such as flow rate. It should be noted that certain embodiments of the present disclosure may exclude at least one valve of the various valves 50, 52. 54. 58. 60. 61, 62, 64, 66, 74, 76. 78 described above. Further, the pump 20 (e.g., variable speed pump) in the illustrated embodiment may' be controlled to a speed setting corresponding to approximately 1350 gallons per minute (GPM) to 1430 GPM, and the pump 24 (e.g., variable speed pump) in the illustrated embodiment may be controlled to a speed setting corresponding to approximately 40 to 60 GPM based on the input(s) to the controller 34.

[0040] By implementing the above-described controls, for example, the load of the system may be handled as indicated in pie chart 202. For example, the dry cooler 30 may handle the majority of the load (e.g., 60% to 70% of the load), the fluid cooler 28 may handle a smaller portion of the load (e.g., 25% to 35% of the load), and the heat reclaim heat exchanger 32 may handle a still smaller portion of the load (e.g., 5% to 10% of the load). It should be understood that the above-described valve and / or pump settings, the generated load distribution indicated in pie chart 200, and the loads handled distribution indicated in pie chart 202 correspond to merely one example based onmerely one set of data, and that other valve settings corresponding to other sets of data may be implemented by the controller 34 in accordance with the present disclosure.

[0041] As previously described, one chiller (e.g., the first chiller 12a) is shown in the illustrated embodiment, although it should be noted that additional chillers may also be included, as previously described. The chiller 12a shown in the illustrated embodiment may be considered a part of the MTHS 10 or separate from (and interfaced with) the MTHS 10. As shown, the chiller 12a may include the condenser 14a, the oil cooler 16a, the evaporator 100a, the compressor 102a, and a separator 110a between the compressor 102a and the condenser 14a and between the compressor 102a and then oil cooler 16a. As previously described, the first pump 20 may be employed to bias the fluid (e.g., the glycol) through the first distribution assembly 18 to the condenser 14a of the chiller 12a, and the second pump 24 may be employed to bias the fluid (e.g., the glycol) through the second distribution assembly 22 and to the oil cooler 16a. The chiller 12a. as shown, may include a refrigerant loop 112a guiding a refrigerant 114a from the compressor 102a to the separator 110a, and then to the condenser 14a, and then to the evaporator 100a, and then back to the compressor 102a. As shown, the condenser 14a may receive the refrigerant 114a and the fluid (e.g., the glycol) associated with the first distribution assembly 18, the evaporator 100a may receive the refrigerant 114a and a process fluid 116a, the compressor 102a may receive the refrigerant 114a and an oil 118a (e.g., for lubrication), and the separator 110a may receive a combination of the refrigerant 114a and the oil 118a. The separator 110a may be configured to separate the refrigerant 114a from the oil 118a, output the refrigerant 114a toward the condenser 14a, and output the oil 118a toward the oil cooler 16a.

[0042] As shown, the heat recover heat exchanger 32 (also referred to in certain instances of the present disclosure as the heat reclaim heat exchanger) may extract heat from the fluid in certain modes via an additional heat reclaim fluid 170, the dry cooler 30 may extract heat from the fluid via a fan 172, and the evaporative fluid cooler 28 may extract heat from the fluid via a spray w ater 174 corresponding to a spray w ater circuit 175, a fan 176, or both. It should be noted that a location of the fan 176 may differ from the illustrated embodiment.

[0043] In accordance with the present disclosure, the dry cooler 30, the evaporative fluid cooler 28, and controls implemented by the controller 34 may be configured toenable operation of the MTHS 10 during (or close to) freezing conditions, to replace water of the spray water circuit 175 (e.g., on a periodic basis), or both. For example, in certain embodiments, the dry cooler 30 may be sized to handle the entire heat rejection load at an ambient temperature above freezing. Additionally or alternatively, the controller 34 may be configured to detect when ambient temperatures approach or reach freezing ambient conditions. For example, the controller 34 may receive, via the one or more inputs 40, sensor feedback (e.g.. temperature feedback) indicative of the freezing ambient conditions and / or the ambient temperature approaching the freezing temperature from one or more sensors 178. In response to such sensor feedback, the controller 34 may control various aspects of the spray water circuit 175, as described below.

[0044] For example, the spray water circuit 175 may include a sprayer assembly 180 configured to spray water on a portion of the evaporative fluid cooler 28, such as a coil 182 configured to receive the fluid or a pad adjacent to the coil 182, a reservoir 184 (e.g., sump, drain pan) configured to collect the water, a drain valve 186, a make-up valve 188, and one or more water pumps 190 configured to bias the water from the reservoir 184 to the sprayer assembly 180. In response to determining that ambient temperature is approaching or has reached freezing conditions, the controller 34 may control the drain valve 186 (e.g., open the drain valve 186). the water pump(s) 190. and / or the make-up valve 188 (e.g., close the make-up valve 188) to drain the reservoir 184 and any associated piping (e.g., to remove the water from the spray water circuit 175). In some embodiments or operating conditions, once the water is drained from the spray water circuit 175, the controller 34 may continue to operate the evaporative fluid cooler 28 via a dry operation mode (e.g., by controlling the fan 176). In some embodiments, the controller 34 may independently control a first speed of the fan 176 of the evaporative fluid cooler 28 and a second speed of the fan 172 of the dry cooler 30 to provide the lowest combined fan and pump energy.

[0045] As temperatures rise sufficiently above freezing, the controller 34 may stop the dry operation mode and / or stop operation of the fan 176 of the evaporative fluid cooler 28 while increasing a speed of the fan 172 of the dry cooler 30 to compensate and continue handling thermal loads, at least until the temperature has risen beyond a dry cooler switch point. Indeed, as previously described, the dry cooler 30 may be sizedto handle such thermal loads while the evaporative fluid cooler 28 is not in normal operation or dry operation. When the temperature has risen beyond the dry cooler switch point, the evaporative fluid cooler 28 may be controlled to introduce additional water thereto (e.g., by closing the drain valve 186, opening the make-up valve 188, and operating the pump 190) and to operate under normal conditions. In this way, the MTHS 10 may be configured to seamlessly transition between freezing temperatures and non-freezing (e.g.. normal) temperatures while handling any thermal loads associated with the MTHS 10.

[0046] In another aspect of the present disclosure, the evaporative fluid cooler 28 may be controlled periodically to replace the water therein, which may negate the need to provide continuous bleed of the water, reduce overall water consumption, and negate the need to provide chemical treatment for scale and biological control. The controller 34 may be programmed to recognize periods of time (e.g., 12 hours, 24 hours, 36 hours, 48 hours, etc.), water quality measurements (e.g., conductivity) via the one or more inputs 40 (e.g., from the one or more sensors 178), or moments in time (e.g., an early morning hour, such as 5 AM) and implement water replacement each period. As an example, water may be replaced every7day at the early morning hour when dry bulb temperature is typically coldest. When each period lapses (e.g., at the early morning hour), the controller 34 may control (e.g., shut off) the water pump(s) 190. close the make-up valve 188, and open the drain valve 186, thereby causing the water to drain from the spray water circuit 175. Additionally, the controller 34 may close the evaporative fluid cooler inlet valve 50 in certain embodiments such that the fluid is blocked (and removed via other means previously described) from the coil 182. Once a pre-defined period of time (e.g., 30 minutes) lapses after draining the water, the controller 34 may turn off the fan 176 of the evaporative fluid cooler 28, close the drain valve 186, and open the make-up valve 188, causing the reservoir 184 (e.g., pan, sump, etc.) to be replenished with water (e.g., from a water source 192).

[0047] FIG. 5 is a process flow diagram illustrating an embodiment of a method 500 of operating a multi -temperature hydronic system (MTHS). It should be noted that, while an embodiment of the method 500 may be performed in an order corresponding to the steps illustrated in FIG. 5 and described in detail below, other embodiments of the method 500 may be performed in a different order. Further, while certain steps ofan embodiment of the method 500 are illustrated in FIG. 5 and described in detail below, certain such steps may be excluded and / or additional steps may be included in certain embodiments of the method 500 in accordance with the present disclosure. In certain embodiments, control aspects of the method 500 may be performed at least in part by a controller, as previously described.

[0048] In the illustrated embodiment, the method 500 may include controlling (block 502) at least one valve of a plurality of valves to control at least one fluid flow of a fluid between a plurality of heat rejection devices of the MTHS and a chiller oil cooler. Further, the method 500 may include controlling (block 504) at least one valve of the plurality of valves to control at least one fluid flow of the fluid between the plurality of heat rejection devices and a chiller condenser. The plurality of heat rejection devices may include, for example, at least two of an evaporative fluid cooler, a dry cooler, or a heat reclaim heat exchanger, among other possible heat rejection devices. By controlling the at least one valve(s) in block 502 and / or block 504. at least one heat rejection device of the plurality of heat rejection devices may be selectively engaged to achieve a target temperature of the fluid at the chiller oil cooler and / or optimize a temperature of the fluid at the chiller condenser. Optimizing the temperature of the fluid at the chiller condenser may mean, for example, controlling the system such that the temperature of the fluid at the chiller condenser is changed toward a desired temperature or target temperature, although other temperature optimization techniques and / or criteria are also possible in accordance with the present disclosure.

[0049] The method 500 also may include controlling (block 506) a spray water circuit of an evaporative fluid cooler of the plurality of heat rejection devices during an operating mode of the MTHS. For example, in some embodiments, the evaporative fluid cooler may include the spray water circuit employed in at least some operating modes to extract heat from the fluid biased between the plurality of heat rejection devise and the chiller oil cooler, the chiller condenser, or both. Further, the method 500 may include controlling (block 508) the spray water circuit to drain water from the spray water circuit in response to an ambient temperature approaching a freezing temperature. F or example, a make-up valve of the spray water circuit may be closed and a drain valve of the spray water circuit may be opened to dram the water from the spray water circuitin response to determining that the ambient temperature is approaching the freezing temperature.

[0050] In some embodiments, after the water is drained from the spray water circuit, the method 500 may include controlling (block 510) the evaporative fluid cooler and a dry cooler of the plurality of heat rejection devices in a dry’ operation mode. In this way, the MTHS may continue to operate below freezing conditions without intermption. As previously described, the dry' operation mode may be employed until the ambient temperature exceeds a dry' cooler switch point, where the dry' cooler switch point may be above the freezing temperature.

[0051] In general, presently disclosed embodiments are configured to more efficiently handle temperature regulation of multiple thermal loads, reduce water consumption, and / or reduce maintenance / servicing costs relative to traditional configurations, among other technical benefits.

[0052] While only certain features and embodiments of the disclosure have been illustrated and described, many modifications and changes may occur to those skilled in the art. such as variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, including temperatures and pressures, mounting arrangements, use of materials, colors, orientations, and so forth without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure. Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described, such as those unrelated to the presently contemplated best mode of carrying out the disclosure, or those unrelated to enabling the claimed disclosure. It should be noted that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. 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, without undue experimentation.

[0053] 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. 112(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).

Claims

CLAIMSWhat is claimed is:

1. A multi-temperature hydronic system (MTHS). comprising: a plurality of heat rej ection devices including at least two of an evaporative fluid cooler, a dry cooler, or a heat recovery heat exchanger; an MTHS skid comprising a plurality of valves controllable to adjust fluid flows of a fluid between: the plurality’ of heat rejection devices and a chiller oil cooler; and the plurality of heat rejection devices and a chiller condenser; and a controller configured to control the plurality of valves to selectively engage at least one heat rejection device of the plurality of heat rejection devices to: achieve a target temperature of the fluid at the chiller oil cooler; or optimize a temperature of the fluid at the chiller condenser.

2. The MTHS of claim 1. wherein the controller is configured to control the plurality of valves to selectively engage the at least one heat rejection device of the plurality’ of heat rejection devices to optimize the temperature of the fluid at the chiller condenser by: maintaining the temperature above a threshold temperature; and reducing the temperature toward the threshold temperature while maintaining the target temperature of the fluid at the chiller oil cooler.

3. The MTHS of claim 1, wherein the evaporative fluid cooler comprises a fan and a spray water circuit, the spray water circuit including: a reservoir configured to collect water; a sprayer assembly configured to spray the water onto a portion of the evaporative fluid cooler; a pump configured to bias the water from the reservoir to the sprayer assembly; a drain valve configured to drain the water from the reservoir; and a make-up valve.

4. The MTHS of claim 3, wherein the controller is configured to:determine that an ambient temperature is approaching a freezing temperature; and close the make-up valve and open the drain valve to drain the water from the spray water circuit in response to determining that the ambient temperature is approaching the freezing temperature.

5. The MTHS of claim 3, wherein the controller is configured to: determine that a pre-defined moment in time has been reached, that a predefined water quality measurement has been reached, or both; and then close the make-up valve and open the drain valve to drain the water from the spray water circuit.

6. The MTHS of claim 1, wherein the plurality' of valves comprises a heat recovery heat exchanger inlet valve and a heat recovery heat exchanger bypass valve, wherein the controller is configured to open the heat recovery heat exchanger inlet valve and close the heat recovery heat exchanger bypass valve during a first operating mode of a plurality of operating modes, and wherein the controller is configured to close the heat recovery heat exchanger inlet valve and open the heat recovery heat exchanger bypass valve during a second operating mode of a plurality of operating modes.

7. The MTHS of claim 1 , wherein the plurality' of valves comprises a dry cooler inlet valve and a dry cooler bypass valve, wherein the controller is configured to open the dry cooler inlet valve and close the dry cooler bypass valve during a first operating mode of a plurality of operating modes, and wherein the controller is configured to close the dry cooler inlet valve and open the dry cooler bypass valve during a second operating mode of the plurality’ of operating modes.

8. The MTHS of claim 1, wherein the plurality of valves comprises an evaporative fluid cooler inlet valve and an evaporative fluid cooler bypass valve, wherein the controller is configured to open the evaporative fluid cooler inlet valve and close the evaporative fluid cooler bypass valve during a first operating mode of a plurality' of operating modes, and wherein the controller is configured to close the evaporative fluid cooler inlet valve and open the evaporative fluid cooler bypass valve during a second operating mode of the plurality of operating modes.

9. The MTHS of claim 1. comprising a header fluidly coupled with the plurality of heat rejection devices, wherein the plurality of valves comprises at least two of: a first fluid injection valve configured to be opened to enable a first flow of the fluid from the chiller condenser toward an inlet to the header; a second fluid injection valve configured to be opened to enable a second flow of the fluid from the chiller condenser to a second location at the header between the heat recovery heat exchanger and the dry cooler; a third fluid injection valve configured to be opened to enable a third flow of the fluid from the chiller condenser to a third location at the header between the dry cooler and the evaporative fluid cooler; or a fourth fluid injection valve configured to be opened to enable a fourth flow of the fluid from the chiller condenser to a fourth location at the header between the dry cooler and the evaporative fluid cooler.

10. The MTHS of claim 1. comprising: a first pump configured to bias a first flow the fluid toward the chiller condenser; and a second pump configured to bias a second flow of the fluid toward the chiller oil cooler, wherein the controller is configured to: determine a first setting of the first pump based on a first target flow rate of the first flow of the fluid; control the first pump to the first setting; determine a second setting of the second pump based on a second target flow rate of the second flow of the fluid; and control the second pump to the second setting.

11. The MTHS of claim 1. comprising: a header configured to distribute the fluid to the plurality of heat rejection devices or a portion of the plurality of heat rejection devices; an outlet conduit coupled between the header and a pump of the MTHS; a first fluid conduit coupled to a location of the header between the dry cooler and the evaporative fluid cooler;a second fluid conduit coupled to an additional location of the outlet conduit between the header and the pump; and a control valve coupled to the first fluid conduit and the second fluid conduit, wherein the controller is configured to control one or more settings of the control valve to blend a first portion of the fluid received from the first fluid conduit and a second portion of the fluid received from the second fluid conduit in at least one operating mode.

12. A multi-temperature hydronic system (MTHS), comprising: a plurality of heat rejection devices including an evaporative fluid cooler and at least one additional heat rejection device; an MTHS skid comprising a plurality of valves controllable to adjust fluid flows of a fluid between the plurality of heat rejection devices and a chiller oil cooler, a chiller condenser, or both; and a spray water circuit of the evaporative fluid cooler, wherein the spray water circuit comprises: a reservoir configured to collect water; a sprayer assembly configured to spray the water onto a portion of the evaporative fluid cooler; a pump configured to bias the water from the reservoir to the sprayer assembly; a drain valve configured to drain the water from the reservoir; and a make-up valve.

13. The MTHS of claim 12, comprising a controller configured to close the make-up valve and open the drain valve to drain the water from the spray water circuit in response to determining that an ambient temperature is approaching a freezing temperature.

14. The MTHS of claim 13, wherein the at least one additional heat rejection device comprises a dry cooler, and the controller is configured to operate the dry cooler and operate the evaporative fluid cooler in a dty' operation mode after the water is drained from the spray water circuit.

15. The MTHS of claim 14, wherein the controller is configured to stop the dry operation mode of the evaporative fluid cooler and increase a speed of a dry cooler fan of the dry cooler in response to determining that the ambient temperature is above the freezing temperature and below a dry cooler switch point.

16. The MTHS of claim 12. comprising a controller configured to control the plurality of valves to selectively engage at least one heat rejection device of the plurality of heat rejection devices to: achieve a target temperature of the fluid at the chiller oil cooler; or optimize a temperature of the fluid at the chiller condenser.

17. A method of operating a multi-temperature hydronic system (MTHS), the method comprising adjusting, via a controller and based on a target temperature of a fluid at a chiller oil cooler, a temperature of the fluid at a chiller condenser, or both, at least one valve of a plurality of valves corresponding to a skid of the MTHS to selectively engage at least one heat rejection device of a plurality of heat rejection devices of the MTHS by adjusting at least one fluid flow of the fluid between the plurality of heat rejection devices and: the chiller oil cooler; the chiller condenser; or both.

18. The method of claim 17. comprising draining, via the controller and based on an ambient temperature approaching a freezing temperature, water from a spray water circuit corresponding to an evaporative fluid cooler of the plurality of heat rejection devices by: closing a make-up valve of the spray water circuit; and opening a drain valve of the spray water circuit.

19. The method of claim 18, comprising controlling, via the controller, a dry cooler of the plurality of heat rejection devices and the evaporative fluid cooler in a dry operation mode after the water is drained from the spray water circuit.

20. The method of claim 19, comprising stopping, via the controller, the dry operation mode of the evaporative fluid cooler and increasing, via the controller, a speed of a dry cooler fan of the dry cooler in response to determining that the ambient temperature is above the freezing temperature and below a dry cooler switch point.

Images