Heat transfer device and method

Abstract

In one aspect, it is a heat transfer device for an industrial process that requires a process fluid at a process fluid set temperature. The heat transfer device includes a process fluid heat exchange circuit having a heat exchanger, an air flow generator, and a thermal energy storage. The controller is at least partially based on the parameters of the air and the determination that the process fluid heat exchange circuit in a first mode in which the process fluid bypasses the thermal energy storage cannot supply the process fluid at the process fluid set temperature, and the thermal energy storage transfers heat between the process fluid and the thermal energy storage, and the heat exchanger transfers heat between the process fluid and the air. It is configured to operate the process fluid heat exchange circuit in a second mode.

Description

Technical Field

[0001] (Cross - Reference to Related Applications)

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 355,449, filed on June 24, 2022, U.S. Provisional Patent Application No. 63 / 407,630, filed on September 17, 2022, and U.S. Provisional Patent Application No. 63 / 427,326, filed on November 22, 2022, all of which are hereby incorporated by reference in their entirety.

[0002]

[0002] This disclosure relates to a system for removing heat from a process fluid, and more particularly, to a packaged cooling system such as a cooling tower.

Background Art

[0003]

[0003] Industrial cooling systems are used to remove heat from process fluids in various industrial processes such as manufacturing processes, building HVAC systems, and heat transfer systems in computer data centers. One common approach for some industrial cooling systems is to install, within a building, a heat exchanger (such as an air handler) that transfers heat to a first process fluid (e.g., water or a mixture of water and glycol), and a chiller that removes heat from the first process fluid. The chiller transfers heat from the first process fluid to a second process fluid, and the second process fluid is sent to a heat removal device such as a cooling tower outside the building. The cooling tower removes heat from the second process fluid and returns the cooled second process fluid to the chiller. Chillers used in industrial cooling systems are typically quite large, and a rated power in the range of 100 - 300 horsepower is common.

[0004]

[0004] The problem of operating an industrial cooling system throughout the year is that the cooling system is typically designed to have sufficient maximum capacity so that it can provide the necessary cooling even on the hottest day of the year. Providing sufficient maximum capacity on the hottest day of the year in a conventional cooling system requires the use of system components that are more performant than necessary for the rest of the year, such as more powerful chillers, fan motors, pumps, etc. More performant system components consume more energy and / or water than less performant components, but are used to provide sufficient maximum capacity to the cooling system.

[0005]

[0005] An ice thermal energy storage system may be used with an industrial cooling system to provide additional cooling capacity when energy usage is at a peak, such as in the afternoon on a sunny and humid summer day. The ice thermal energy storage system has a thermal energy storage tank that is filled (e.g., ice in the tank is frozen) and discharged as needed to complement the chiller and cooling tower of the cooling system. For example, the ice thermal energy storage system may operate to freeze the water in the tank at night when the electricity rate from the local power company is low. The ice thermal energy storage system is discharged, such as by having the ice in the tank melted by a process fluid passing through coils in the ice tank, on a sunny and humid summer afternoon, improving the cooling capacity of the cooling system.

[0006]

[0006] Some problems associated with partial cooling systems that utilize ice thermal storage still rely on large chillers (e.g., 200 horsepower or more) within a building to cool the water supplied to heat exchangers within the building. While these large chillers provide sufficient maximum capacity, they often consume large amounts of energy even when the required cooling capacity is low. Another problem associated with some ice thermal storage cooling systems is that one or more ice tanks may occupy an entire room or another building in order to provide sufficient cooling capacity for large industrial cooling systems. The size and complexity of large ice thermal storage tanks may not be practical for some facilities. Furthermore, ice thermal storage systems use glycol, which is more expensive than water as a process fluid, increasing the pump power required to circulate the process fluid and reducing the heat transfer performance.

Summary of the Invention

[0007]

[0007] In one aspect of the present disclosure, a heat transfer device for an industrial process that requires a process fluid at a process fluid set temperature is provided. The heat transfer device includes an air inlet, an air outlet, and a process fluid heat exchange circuit that receives the process fluid from the industrial process at a temperature different from the process fluid set temperature and supplies the process fluid to the industrial process at the process fluid set temperature. The process fluid heat exchange circuit includes a heat exchanger, an air flow generator operable to move air from the air inlet to the air outlet and bring it into contact with the heat exchanger, and a thermal energy storage.

[0008]

[0008] The process fluid heat exchange circuit has a first mode in which the process fluid bypasses the thermal energy storage and the heat exchanger transfers heat between the process fluid and air. The process fluid may bypass the thermal energy storage, for example, by being sent around the thermal energy storage when the heat exchange capacity of the thermal energy storage is limited or by being sent to the thermal energy storage. As a further example, the process fluid may bypass the thermal energy storage when the process fluid passes through the thermal energy storage but the phase change material is discharged from the thermal energy storage such that it exits the thermal energy storage at approximately the same temperature as when the process fluid enters the thermal energy storage. The process fluid heat exchange circuit has a second mode in which the thermal energy storage transfers heat between the process fluid and the thermal energy storage and the heat exchanger transfers heat between the process fluid and air. The heat transfer device further comprises a controller operably connected to the process fluid heat exchange circuit.

[0009]

[0009] The controller is configured to operate the process fluid heat exchange circuit in the second mode based at least in part on an air parameter and a determination that the process fluid heat exchange circuit in the first mode cannot supply the process fluid at a process fluid set temperature. In this way, the heat transfer device may utilize the thermal energy storage to adjust or partially satisfy the heat transfer load required to supply the process fluid at the process fluid set temperature. By selectively utilizing the thermal energy storage at peak heat transfer loads such as on the hottest day of the year, the heat exchanger can be sized to be smaller than if it were to attempt to satisfy the peak heat transfer load itself, thereby promoting less water and / or energy use by the heat exchanger during off-peak heat transfer load situations.

[0010]

[0010] The present disclosure also provides a method of operating a heat transfer device associated with an industrial process that requires a process fluid at a process fluid set temperature. The heat transfer device comprises a process fluid heat exchange circuit for the process fluid, the process fluid heat exchange circuit comprising a heat exchanger, a fan that causes movement of air across the heat exchanger, and a heat energy storage. The process fluid heat exchange circuit has a first mode in which the process fluid bypasses the heat energy storage and the heat exchanger transfers heat between the process fluid and the air. The process fluid heat exchange circuit has a second mode in which the heat energy storage transfers heat between the process fluid and the heat energy storage and the heat exchanger transfers heat between the process fluid and the air. The method includes operating the process fluid heat exchange circuit in the second mode based at least in part on an air parameter and a determination that the process fluid heat exchange circuit in the first mode cannot supply the process fluid to the industrial process at the process fluid set temperature.

[0011]

[0011] In one aspect of the present disclosure, there is provided a heat transfer device comprising a process fluid heat exchange circuit including a heat exchanger, an air flow generator operable to bring air into contact with the heat exchanger, a thermal energy storage, and a mechanical cooler. The process fluid heat exchange circuit has a plurality of modes including a first mode in which the heat exchanger is operable to transfer heat between the process fluid and air, a second mode in which the heat exchanger is operable to transfer heat between the process fluid and air and the mechanical cooler is operable to remove heat from the process fluid. The plurality of modes further include a third mode in which the heat exchanger is operable to transfer heat between the process fluid and air and the thermal energy storage is operable to remove heat from the process fluid, and a fourth mode in which the heat exchanger is operable to transfer heat between the process fluid and air, the mechanical cooler is operable to remove heat from the process fluid, and the thermal energy storage is operable to remove heat from the process fluid. The heat transfer device further includes a controller configured to operate the process fluid heat exchange circuit in one of the plurality of modes based at least in part on a determination of the heat duty of the heat transfer device. Thus, the controller may operate the process fluid heat exchange circuit in various configurations based at least in part on the heat duty, thereby providing flexibility in adjusting the heat transfer device for efficiently removing heat from the process fluid.

[0012] In another aspect of the present disclosure, a heat transfer device is provided that includes an air inlet, an air outlet, and a process fluid cooling system for cooling a process fluid. The process fluid cooling system includes a fan assembly that moves air from the air inlet to the air outlet, a dehumidifier having a dehumidification mode in which the dehumidifier removes moisture from the air and a bypass mode in which the dehumidifier removes less moisture from the air than when the dehumidifier is in the dehumidification mode, and an adiabatic pre-cooler having a pre-cooling mode in which the adiabatic pre-cooler lowers the dry bulb temperature of the air and a standby mode in which the adiabatic pre-cooler lowers the dry bulb temperature of the air lower than when the adiabatic pre-cooler is in the pre-cooling mode. The heat transfer device further includes a heat exchanger that receives the process fluid and is downstream of the dehumidifier and the adiabatic pre-cooler. The process fluid cooling system has a first mode in which the dehumidifier is in the dehumidification mode and the adiabatic pre-cooler is in the pre-cooling mode, a second mode in which the dehumidifier is in the bypass mode and the adiabatic pre-cooler is in the pre-cooling mode, and a third mode in which the dehumidifier is in the bypass mode and the adiabatic pre-cooler is in the standby mode. Thus, the dehumidifier and the adiabatic pre-cooler may selectively operate to meet the operating criteria of the heat transfer device, such as supplying the process fluid at a process fluid set temperature, meeting the heat transfer load, minimizing energy consumption, and / or minimizing water consumption. Further, the heat transfer device may include a moisture recovery system that recovers moisture removed from the air by the dehumidifier. The recovered moisture may, for example, be utilized as makeup water for the adiabatic pre-cooler by the heat transfer device.

[0013]

[0013] The present disclosure also provides a heat transfer device having a heat exchanger for cooling a process fluid, the heat exchanger having a liquid distribution system and a fan operable to move air across the heat exchanger. The heat exchanger has a wet mode in which the liquid distribution system distributes liquid and a dry mode in which the liquid distribution system distributes less liquid than in the wet mode. The heat transfer device further includes a thermal energy reservoir having a heat transfer mode in which the thermal energy reservoir removes heat from the process fluid and a bypass mode in which the thermal energy reservoir removes less heat from the process fluid than when in the heat transfer mode. The heat transfer device further includes a controller configured to receive either a request to minimize water consumption or a request to minimize energy consumption and to determine a heat duty of the heat transfer device from a plurality of heat duties including a low heat duty, an intermediate heat duty, and a high heat duty. In response to receiving a request to minimize water consumption, the controller is configured to operate the heat exchanger in the dry mode and the thermal energy reservoir in the bypass mode, at least partially based on the heat duty being the low heat duty, to operate the heat exchanger in the dry mode and the thermal energy reservoir in the heat transfer mode, at least partially based on the heat duty being the intermediate heat duty, and to operate the heat exchanger in the wet mode and the thermal energy reservoir in the heat transfer mode, at least partially based on the heat duty being the high heat duty. In response to receiving a request to minimize energy consumption, the controller is configured to operate the heat exchanger in the wet mode and the thermal energy reservoir in the bypass mode, at least partially based on the heat duty being the low heat duty, and to operate the heat exchanger in the wet mode and the thermal energy reservoir in the heat transfer mode, at least partially based on the heat duty being the high heat duty. Thereby, the controller may operate the components of the heat transfer device in various modes in response to the heat duty and a request to minimize water or energy consumption, thereby operating the heat transfer device accurately and efficiently to, for example, provide a requested process fluid set temperature.

Brief Description of the Drawings

[0014]

Figure 1

[0014] It is a schematic diagram of a heat transfer device according to the first approach.

Figure 2

[0015] It is a more detailed schematic diagram of the heat transfer device in FIG. 1.

Figure 3

[0016] It is a schematic diagram of a heat transfer device which is the first example of the heat exchanger in FIG. 1.

Figures 4A - 4B

[0017] It is a diagram showing the states of various components of the heat transfer device in FIG. 3 in various operating modes while minimizing water consumption and discharging the phase change material.

Figures 5A - 5B

[0018] It is a diagram showing the states of components of the heat transfer device in FIG. 3 in various operating modes while minimizing energy consumption and discharging the phase change material.

Figures 6A - 6B

[0019] It is a diagram showing the states of components of the heat transfer device in FIG. 3 in various operating modes while minimizing water consumption and filling the phase change material.

Figures 7A - 7B

[0020] It is a diagram showing the states of components of the heat transfer device in FIG. 3 in various operating modes while minimizing energy consumption and filling the phase change material.

Figure 8

[0021] It is a schematic diagram of the second example of the heat transfer device in FIG. 1.

Figures 9A - 9B

[0022] It is a diagram showing the states of components of the heat transfer device in FIG. 8 in various operating modes while minimizing water consumption and discharging the phase change material.

Figures 10A - 10B

[0023] It is a diagram showing the states of components of the heat transfer device in FIG. 8 in various operating modes while minimizing energy consumption and discharging the phase change material.

Figures 11A - 11B

[0024] FIG. 8 is a diagram showing the state of components of the heat transfer device while minimizing water consumption and in various operating modes during filling of the phase change material.

Figures 12A - 12B

[0025] FIG. 8 is a diagram showing the state of components of the heat transfer device while minimizing energy consumption and in various operating modes during filling of the phase change material.

Figure 13

[0026] FIG. 8 is a schematic diagram of a third example of the heat transfer device of FIG. 1 having a secondary closed loop pump for promoting filling of the phase change material.

Figures 14 - 19

[0027] FIG. 13 is a schematic diagram of the heat transfer device in various operating modes.

Figures 20A - 20B

[0028] FIG. 13 is a diagram showing the state of components of the heat transfer device while minimizing water consumption and in various operating modes during discharging of the phase change material.

Figures 21A - 21B

[0029] FIG. 13 is a diagram showing the state of components of the heat transfer device while minimizing energy consumption and in various operating modes during discharging of the phase change material.

Figures 22A - 22B

[0030] FIG. 13 is a diagram showing the state of components of the heat transfer device while minimizing energy consumption and in various operating modes during filling of the phase change material.

Figures 23A - 23B

[0031] FIG. 13 is a diagram showing the state of components of the heat transfer device while minimizing energy consumption and in various operating modes during filling of the phase change material.

Figure 24

[0032] A fourth example of the heat transfer device of FIG. 1 having a direct heat exchanger and an indirect heat exchanger for removing heat from the process fluid.

Figure 25

[0033] A fifth example of the heat transfer device of FIG. 1 having a direct heat exchanger for removing heat from the process fluid.

Figure 26

[0034] Schematic diagram of a heat transfer device according to a second approach.

Figure 27

[0035] A more detailed schematic diagram of the heat transfer device of FIG. 26.

Figure 28

[0036] Schematic diagram of a first example of the heat transfer device of FIG. 26.

Figures 29 - 32

[0037] Schematic diagram of the heat transfer device of FIG. 28 in different operating modes.

Figure 33

[0038] A diagram showing the states of the components of the heat transfer device in various operating modes while the heat transfer device of FIG. 28 minimizes water consumption and discharges the phase change material.

Figure 34

[0039] A diagram showing the states of the components of the heat transfer device in various operating modes while the heat transfer device of FIG. 28 minimizes energy consumption and discharges the phase change material.

Figure 35

[0040] A diagram showing the states of the components of the heat transfer device in various operating modes while the heat transfer device of FIG. 28 minimizes water consumption and fills the phase change material.

Figure 36

[0041] A diagram showing the states of the components of the heat transfer device in various operating modes while the heat transfer device of FIG. 28 minimizes energy consumption and fills the phase change material.

Figure 37

[0042] Schematic diagram of a second example of the heat transfer device of FIG. 26.

Figure 38

[0043] A diagram showing the states of the components of the heat transfer device of FIG. 37 in various operating modes while the heat transfer device minimizes water consumption and discharges the phase change material.

Figure 39

[0044] A diagram showing the states of the components of the heat transfer device of FIG. 37 in various operating modes while the heat transfer device minimizes energy consumption and discharges the phase change material.

Figure 40

[0045] FIG. 37 is a diagram showing the state of components of the heat transfer device while minimizing water consumption and during various operating modes while filling the phase change material.

Figure 41

[0046] FIG. 4 is a diagram showing the state of components of the heat transfer device of FIG. 37 in the adiabatic cooling mode while minimizing energy consumption and during filling of the phase change material.

Figure 42

[0047] FIG. 8 is a schematic diagram of a third example of the heat transfer device of FIG. 26.

Figure 43

[0048] FIG. 12 is a schematic diagram of a fourth example of the heat transfer device of FIG. 26.

Figure 44

[0049] FIG. 16 is a schematic diagram of a heat transfer device according to a third approach.

Figure 45

[0050] FIG. 20 is a schematic diagram of a first example of the heat transfer device of FIG. 44.

Figures 46 - 49

[0051] FIG. 24 is a schematic diagram of a part of the heat transfer device of FIG. 45 showing various operating modes.

Figure 50

[0052] FIG. 28 is a diagram showing the state of components of the heat transfer device of FIG. 45 in various operating modes while minimizing energy consumption.

Figure 51

[0053] FIG. 32 is a diagram showing the state of components of the heat transfer device while the heat transfer device of FIG. 45 minimizes water consumption.

Figure 52

[0054] FIG. 36 is a diagram showing the state of components of the heat transfer device of FIG. 45 in various operating modes while the heat transfer device generates water.

Figure 53

[0055] FIG. 40 is a schematic diagram of a second example of the heat transfer device of FIG. 44.

Figure 54

[0056] FIG. 44 is a diagram showing the state of components of the heat transfer device of FIG. 53 in various operating modes while minimizing energy consumption.

Figure 55

[0057] It is a diagram showing the states of components of the heat transfer device in various operation modes while the heat transfer device of FIG. 53 minimizes water consumption.

Figure 56

[0058] It is a diagram showing the states of components of the heat transfer device in various operation modes while the heat transfer device of FIG. 53 generates water.

Figure 57

[0059] It is a schematic diagram of a third example of the heat transfer device of FIG. 44.

Figure 58

[0060] It is a schematic diagram of a fourth example of the heat transfer device of FIG. 44.

Figure 59

[0061] It is a schematic diagram of the heat transfer device in chiller on mode.

Figure 60

[0062] It is a schematic diagram of the heat transfer device of FIG. 59 in chiller off mode.

Figure 61

[0063] It is a schematic diagram of a heat transfer device having a chiller condenser coil downstream of a finned coil when air passes through the heat transfer device.

Figures 62 - 63

[0064] It is a schematic diagram of the heat transfer device when the heat transfer device is in chiller on mode and chiller off mode.

Figures 64 - 67

[0065] It is a schematic diagram of the heat transfer device showing various modes of the heat transfer device.

Figure 68

[0066] It is a schematic diagram of a heat transfer device having a chiller evaporator within the external structure of the heat transfer device.

Figure 69

[0067] It is a perspective view of the heat transfer device of FIG. 68 showing a heat transfer device having a heat energy storage tank alongside an evaporator.

Figures 70 - 73

[0068] It is a schematic diagram of the heat transfer device in various operation modes.

Figures 74 - 75

[0069] It is a schematic diagram of a heat transfer device having a phase change material with a rising storage temperature in various operation modes of the heat transfer device.

Figure 76

[0070] It is a schematic diagram of a heat transfer device having a phase change material tank bypass.

Figure 77

[0071] It is a perspective view of a heat transfer device having two stacked air / process fluid heat exchangers and a phase change material tank.

Figure 78

[0072] It is a schematic diagram of a heat transfer device having a housing and a phase change material tank inside the housing.

Figure 79

[0073] It is a schematic diagram of a heat transfer device having a membrane mass exchanger that dehumidifies air before the air reaches the heat exchanger of the heat transfer device.

Figure 80

[0074] It is a schematic diagram of a heat transfer device having a membrane mass exchanger that is upstream of an adiabatic cooling pad and a finned coil, dehumidifies air, and improves the heat transfer efficiency between the finned coil and the air flow.

Figure 81

[0075] It is a schematic diagram of a vacuum membrane mass exchanger with a sheet membrane interposed between an air passage and a permeation passage.

Figure 82

[0076] It is a schematic diagram of a heat transfer device having a dehumidifier that uses a liquid desiccant to dehumidify air before the air reaches the indirect heat exchanger of the heat transfer device.

Figure 83

[0077] It is a schematic diagram of a heat transfer device having a shape memory alloy cooler.

Figure 84

[0078] It is a graph showing the relationship between the temperature and entropy of the shape memory alloy material of the shape memory alloy cooler.

Modes for Carrying Out the Invention

[0015]

[0079] Referring to FIG. 1, a heat transfer device 10 according to a first approach is provided. The heat transfer device 10 has an external structure such as a housing 12, one or more air inlets 14, and one or more air outlets 16. The heat transfer device 10 has a heat exchanger 19 for transferring heat between a process fluid and air moving from the air inlet 14 to the air outlet 16. The heat exchanger 19 may utilize various air / process fluid flow configurations such as cross-flow, counter-flow, co-current flow, or combinations thereof. The heat transfer device 10 further includes a thermal energy storage (TES) such as a phase change material (PCM) tank 26 for performing additional heat transfer to the process fluid, and a mechanical cooler such as a heat pump or chiller 28. The PCM in the PCM tank 26 may have a fixed or variable freezing temperature. The heat exchanger 19 includes an adiabatic pre-cooler 20 having a pre-cooling pad 22 and an indirect heat exchanger such as a fluid cooling coil 24. The heat transfer device 10 has an air flow generator such as one or more fans 30 operable to generate an air flow that enters from the air inlet 14, crosses the pre-cooling pad 22 and the fluid cooling coil 24, and exits from the air outlet 16. The one or more fans 30 may be fixed speed fans or variable speed fans. The PCM tank 26 and the chiller 28 can perform trim cooling as needed to meet the cooling load requirements, and at the same time size the fans 30, the adiabatic pre-cooler 20, and the indirect heat exchanger 23 to be below the peak cooling load, reducing water consumption and / or energy consumption according to the off-peak cooling load. Thereby, the heat transfer device 10 may meet the peak cooling load or the required process fluid set temperature for an industrial process at a specific geographical location even on the hottest day of the year. Further, the heat transfer device 10 is operable to minimize either water consumption or energy consumption while meeting the cooling load throughout the year.

[0016]

[0080] With reference to FIG. 2, a more detailed schematic view of the heat transfer device 10 is shown. The heat transfer device 10 includes a process fluid inlet 34 that receives a process fluid, such as water or a water / glycol mixture, from an industrial process, such as a computer data center. In one embodiment, a plurality of heat transfer devices 10 may be arranged in parallel such that the process fluid inlet 34 receives the process fluid from an upstream heat transfer device 10. The process fluid received at the process fluid inlet 34 may be a liquid, a gas, or a liquid / gas mixture. The heat transfer device 10 has a process fluid outlet 36 for returning the process fluid to the industrial process or to a downstream heat transfer device. The heat transfer device 10 may operate to cool or heat the process fluid received at the process fluid inlet 34, depending on the requirements of a particular embodiment.

[0017]

[0081] The heat transfer device 10 has a controller 40 that includes a memory 42, which is a non-transitory computer-readable medium for storing instructions to operate the heat transfer device 10. The controller 40 has a processor 44 that executes the instructions stored in the memory 42 and controls the heat transfer device 10. The controller 40 further includes a communication circuit 46 for communicating with a remote device, such as a building HVAC system controller. The communication circuit 46 receives process fluid variables, such as at least one of temperature, pressure, and flow rate, requested by the remote device to be provided to the heat transfer device 10. The processor 44 stores the process fluid variables in the memory 42 and operates the heat transfer device 10 to supply a process fluid that satisfies the process fluid variables to the process fluid outlet 36. The communication circuit 46 not only transmits data, such as air temperature and / or pressure, process fluid temperature, flow rate, and / or pressure, and / or component status data, to the remote device, but may also receive other data from the remote device.

[0018]

[0082] The heat-insulating pre-cooler 20 includes an evaporative liquid distribution system 50 configured to distribute an evaporative liquid such as water onto a pre-cooling pad 22. The evaporative liquid distribution system 50 includes a sump 52 that collects the evaporative liquid from the pre-cooling pad 22, and a pump 54 that sends the evaporative liquid from the sump 52 to a liquid distributor such as a spray nozzle of the evaporative liquid distribution system 50 to distribute the evaporative liquid onto the pre-cooling pad 22. The evaporative liquid distribution system 50 further includes a replenishment valve 56 that allows water to be added to the sump 52 to supplement the evaporation of the evaporative liquid, a liquid level sensor 58 that detects the level of the evaporative liquid in the sump 52, a drain valve 60 for emptying the sump 52, and a conductivity sensor 62 for monitoring one or more variables of the evaporative liquid in the sump 54.

[0019]

[0083] The chiller 28 may take various forms, such as, by way of example, a refrigerant-based chiller, a solid-state chiller (e.g., electrocaloric, magnetocaloric, thermoelastic), or a gas-based chiller (reverse Brayton cycle). In the embodiment of FIG. 2, the chiller 28 is a refrigerant-based chiller and includes a condenser 64, an evaporator 66, a compressor 68, and an expansion valve 70.

[0020]

[0084] The heat transfer device 10 has a process fluid distribution system 80 for directing the flow of the process fluid among the components of the heat transfer device 10. The process fluid distribution system 80 may include one or more bypass pumps 82, a throttle valve 84, and a bypass valve 86. Certain valves may function as either a bypass valve or a throttle valve depending on the mode of the heat transfer device 10, as will be considered in more detail below.

[0021]

[0085] The PCM tank 26 includes a phase change material 90 such as ice or another phase change material having a melting temperature exceeding 32°F, and a heat exchanger 92 for exchanging heat between the phase change material 90 and the process fluid. The phase change material 90 may include, as some examples, ice, paraffin wax, non-paraffin organic substances, hydrated salts, or metals. The PCM tank 26 further includes a drain valve 94 for emptying the PCM tank 26, a flow valve 96 for filling the PCM tank 26, a pneumatic pressure sensor 98 for detecting the pneumatic pressure within the PCM tank 26, a bleed valve 100 for releasing the pneumatic pressure from the PCM tank 26 when the pneumatic pressure exceeds a predetermined threshold, and a PCM filling sensor 102. An example of the PCM filling sensor 102 is a liquid level sensor for PCM having various solid and liquid densities. Another example of the PCM filling sensor 102 is one or more temperature probes located at various locations on the PCM tank 26. The PCM tank 26 further includes a humidity control system 104 for detecting the humidity within the PCM tank 26. The humidity control system 104 may include a relative humidity sensor 106 and a humidity control device 108 such as a dehumidifier.

[0022]

[0086] The PCM tank 26 has an air distribution system 101 for blowing air into the PCM tank 26 to stir the liquid PCM and promote faster and more uniform melting and / or freezing of the PCM. The air distribution system 101 directs air to the PCM at the bottom of the PCM tank 26, and the air stirs the PCM as it rises within the PCM tank 26. To provide this function, the air distribution system 101 may include, as shown in FIG. 2, an air pump, a check valve, a relative humidity sensor, and a humidity control device such as a vent.

[0023]

[0087] The heat transfer device 10 of the first approach may take various forms. Referring to FIG. 3, a heat transfer device 110, which is a first example of the heat transfer device 10, is shown. The heat transfer device 110 includes a process fluid heat exchange circuit 111 that is operable to receive a process fluid from a cooling load 136, cool the process fluid to obtain a required process fluid variable such as a process fluid set temperature, and return the cooled process fluid to the cooling load 136. The heat transfer device 110 has a controller 113 for operating the components of the process fluid heat exchange circuit 111.

[0024]

[0088] The process fluid heat exchange circuit 111 includes a heat exchanger 112 having an adiabatic precooler 114 and an indirect heat exchanger such as a fluid cooling coil 116. The adiabatic precooler 114 has a precooling pad 118 and an evaporative liquid distribution system 120 for distributing an evaporative liquid onto the precooling pad 118. The evaporative liquid distribution system 120 includes a sump 121 for collecting the evaporative liquid from the precooling pad 118 and a sump pump 122 operable to send the evaporative liquid from the sump 120 back to the precooling pad 118.

[0025]

[0089] The heat transfer device 110 includes a fan 124 for generating an air flow across the precooling pad 118 and the fluid cooling coil 116. The adiabatic precooler 114 lowers the dry bulb temperature of the air before the air reaches the fluid cooling coil 116, improving the heat transfer efficiency between the air and the fluid cooling coil 116. The heat transfer device 110 further includes a chiller 130 having a condenser 132 and an evaporator 134 configured to effect heat transfer with the process fluid from the cooling load 136. The heat transfer device 110 has a PCM tank 138 and a closed loop pump 140 used to refill the PCM tank 138, as will be discussed in more detail below. The heat transfer device 110 is organized as a base module 142 that can be added in series or parallel to other base modules to provide a desired amount of cooling capacity to the cooling load 136. The components of the heat transfer device 110 may be within a single external structure or may be arranged in multiple external structures depending on the requirements of a particular embodiment.

[0026]

[0090] With respect to FIGS. 4A and 4B, a method 150 for operating a heat transfer device 110 is shown. The method 150 is shown as a chart organized by a heat duty 152 that increases from an easy (154) heat duty to a hard (156) heat duty. The heat duty of the heat transfer device 110 may be determined by one or more variables such as ambient air temperature (e.g., wet bulb and / or dry bulb), ambient air humidity, temperature and / or humidity of the air inside the heat transfer device 110, process fluid set temperature, process fluid pressure, process fluid flow rate, time, season, or a combination thereof. The method 150 has a logic 158 that facilitates a transition between operating modes 160 of the heat transfer device 110 when the heat duty 152 changes. In one embodiment, the controller 113 makes a progression from a "more easy" operating mode 160 to a "more hard" operating mode 160 in response to the heat transfer device 110 in the "more easy" operating mode 160 being unable to meet, for example, a process fluid set temperature required by an HVAC system controller.

[0027]

[0091] The method 150 further includes a variable 162 of a component of the heat transfer device 110 that changes when the heat transfer device 110 transitions between operating modes 160. In the method 150, the controller 113 has received a request to minimize water consumption such that the method 150 represents a water conservation sequence option. The request may be received from a remote device via the communication circuit 46 or may be determined by the controller 113 based on data available to the controller 113 (such as ambient air variables, process fluid variables, variables indicating the state of components of the heat transfer device 110, or a combination thereof). Further, the PCM tank 138 is drainable in the method 150.

[0028]

[0092] More specifically, the operating mode 160 may include a dry cooling mode 164 that is a default mode initiated by the controller 113 in response to a request to supply the process fluid to the cooling load 136 at a process fluid set temperature for the heat transfer device 110. In the dry cooling mode 164, the variable 162 includes the fan state 166, the sample pump state 168, the state 170 of whether the process fluid is flowing through the fluid cooling coil 116, the state 172 of whether the evaporator 134 and the PCM tank 138 are bypassed, the state 174 of the chiller 130, the state 176 of the closed loop pump 140, and the state 178 of whether the process fluid is flowing through the condenser 132 of the chiller 130. The variable 162 further includes the state 180 of whether the process fluid is flowing through the evaporator 134 of the chiller 130, the state 182 of whether the process fluid is flowing through the PCM tank 138, the filling state 184 of the PCM tank 138, and the state 186 regarding the mode of the PCM tank 138. The state 186 indicates whether the PCM tank 138 is available for discharge or filling during the various operating modes 160 of the method 150.

[0029]

[0093] In the dry cooling mode 164, the fan 124 is on, the sample pump 122 is off, the process fluid flows through the fluid cooling coil 116, and the evaporator 134 and the PCM tank 138 of the chiller 130 are completely bypassed. Further, in the dry cooling mode 164, the chiller 130 is off, the closed loop pump 140 is off, the process fluid bypasses the condenser 132 of the chiller 130, and the process fluid cannot flow through the evaporator 134 of the chiller 130. Furthermore, in the dry cooling mode 164, the process fluid bypasses the PCM tank 138, and the filling rate of the PCM tank 138 is 0% or more.

[0030]

[0094] When the heat duty 152 becomes hard or the heat load increases, the controller 113 changes from the dry cooling mode 164 to another operating mode 160 based on a determination 188 of whether the filling rate of the PCM tank 138 is greater than a predetermined minimum threshold such as 10%, 5%, or 0%. In the method 150, the predetermined minimum threshold is 0%.

[0031]

[0095] When the filling rate of the PCM tank 138 is greater than a predetermined minimum threshold, the controller 113 enters the dry cooling and phase change material mode 190. In the dry cooling and phase change material mode 190, a portion of the process fluid enters the evaporator 134 of the chiller 130 and the PCM tank 138, and a portion of the process fluid bypasses the evaporator 134 and the PCM tank 138 as indicated by reference numerals 192 and 194 of the method 150. Further, in the dry cooling and phase change material mode 190, the PCM tank 138 is in the discharge mode as indicated by reference numeral 196.

[0032]

[0096] On the other hand, when the controller 113 determines (188) that the filling rate of the PCM tank is not greater than a predetermined minimum threshold, the controller 113 may skip the dry cooling and PCM mode 190 and proceed to the dry cooling chiller mode 200. The dry cooling and chiller mode 200 enables a higher cooling capacity than the dry cooling mode 164. In the dry cooling and chiller mode 200, as indicated by reference numerals 202 and 204, a portion of the process fluid flows through the condenser 132 and the evaporator 134 of the chiller 130, and the chiller 130 is on as indicated by reference numeral 206. Since the filling rate of the PCM tank 138 is 0%, the process fluid does not flow through the PCM tank 138 as indicated by reference numeral 208.

[0033]

[0097] When the heat duty 152 continues to increase when the heat transfer device 110 is in the dry cooling and chiller mode 200, the controller 113 determines whether the fill rate of the PCM tank is greater than 0% (210). When the fill rate of the PCM tank is greater than 0%, the controller 113 changes the heat transfer device 110 to the dry cooling, chiller, and PCM mode 212 to respond to the increase in the heat duty 152. As shown in FIGS. 4A and 4B, the controller 113 may enter from the dry cooling and chiller mode 200 to the dry cooling, chiller, and PCM mode 212 through the dry cooling and chiller mode 200 when the fill rate of the tank is 0%, or alternatively, the controller 113 may enter from the dry cooling and PCM mode 190 to the dry cooling, chiller, and PCM mode 212 when the fill rate of the PCM tank 138 is greater than zero. In the dry cooling, chiller, and PCM mode 212, a portion of the process fluid flows through the chiller condenser 132 and the chiller evaporator 134 as indicated by reference numerals 214 and 216, and the chiller 130 is on as indicated by reference numeral 218. Since the fill rate of the PCM tank 138 is greater than zero, the process fluid passes through the PCM tank 138 as indicated by reference numeral 220 and the process fluid is cooled, and the PCM tank 138 is in the discharge mode as indicated by reference numeral 222.

[0034]

[0098] The controller 113 may change the operation of the heat transfer device 110 from the dry cooling, chiller, and PCM mode 212 to the adiabatic cooling and PCM mode 224 when the controller 113 determines that the fill rate of the PCM tank is greater than 0% (226) and the heat duty 152 continues to increase. In the adiabatic cooling and PCM mode 224, the sample pump 122 is on as indicated by reference numeral 228 to send the evaporative liquid to the pre-cooling pad 118. In the adiabatic cooling PCM mode 224, the chiller 130 is off as indicated by reference numeral 230, and the process fluid does not flow through the chiller condenser 132 or the chiller evaporator 134 as indicated by reference numerals 232 and 234. The process fluid flows through the PCM tank 138 as indicated by reference numeral 236, and the PCM tank 138 is in the discharge mode 238 to remove heat from the process fluid.

[0035]

[0099] Method 150 includes the controller 113 determining (242) that the fill rate of the PCM tank 138 exceeds 0% and, in response to the thermal duty 152 continuing to increase, changing the heat transfer device 110 from the adiabatic cooling and PCM mode 224 to the adiabatic cooling and chiller mode 240. In the adiabatic cooling and chiller mode 240, the sump pump 122 is on, as indicated by reference numeral 241, to wet the pre-cooling pad 118 and lower the dry bulb temperature of the air within the heat transfer device 110 before the air reaches the fluid cooling coil 116. As indicated by reference numerals 244, 246, and 248, the chiller 130 is on and at least a portion of the process fluid flows through the chiller condenser 132 and the chiller evaporator 134. Since the fill rate of the PCM tank 138 is 0% at step 242, the process fluid does not flow within the PCM tank 138 as indicated by reference numeral 250 in the adiabatic cooling and chiller mode 240.

[0036]

[0100] The heat transfer device 110 may enter from the adiabatic cooling and PCM mode 224 to the adiabatic cooling and chiller mode 240 when the fill rate of the PCM tank is 0%. Alternatively, the heat transfer device 110 may enter from the dry cooling and chiller mode 200 or the dry cooling, chiller, and PCM mode 212 to the adiabatic cooling and chiller mode 240 when the controller 113 determines at either step 210 or 226 that the fill rate of the PCM tank 138 is 0% and the thermal duty 152 continues to increase.

[0037]

[0101] When the controller 113 determines that the filling rate of the PCM tank 138 exceeds 0% (242) and in response to the thermal duty 152 increasing to the hard (156) level, the heat transfer device 110 may be reconfigured from the adiabatic cooling and PCM mode 224 to the adiabatic cooling, chiller, and PCM mode 252. In the adiabatic cooling, chiller, and PCM mode 252, the sample pump 122 is on as indicated by reference numeral 254, the chiller 130 is on as indicated by reference numeral 256, at least a portion of the process fluid flows through the chiller condenser 132 and the chiller evaporator 134 as indicated by reference numerals 258, 260, and the process fluid flows through the PCM tank 130 as indicated by reference numeral 262. The PCM tank 138 is in the discharge mode as indicated by reference numeral 264 and removes heat from the process fluid.

[0038]

[0102] When the thermal duty 152 increases or decreases, the controller 113 may proceed to the operating mode 160 according to the logic 158. Alternatively, the controller 113 may switch from one operating mode 160 to another (e.g., from mode 164 to mode 252 or vice versa) in response to a sudden change in the thermal duty 152 imposed on the heat transfer device 110.

[0039]

[0103] Referring to FIGS. 5A and 5B, the controller 113 may utilize the method 270 in response to receiving a request to minimize energy consumption and the PCM tank 138 being drainable for trim cooling. The method 270 includes an operating mode 272 that the controller 113 may proceed to when the thermal duty 274 changes from the initial or easy (276) level to the maximum or hard (278) level. The method 270 is similar to the method 150 in many respects. One difference is that the method 270 utilizes adiabatic cooling in modes 280, 282, 284, 286 to limit energy consumption.

[0040]

[0104] Referring to FIGS. 6A and 6B, the controller may utilize method 300 in response to the controller 113 receiving a request to minimize water consumption and the PCM tank 138 being fillable. Method 300 includes an operating mode 302 that the controller 113 proceeds to when the heat duty 304 changes. Method 300 is similar to method 150 above in many respects and includes a variable 306 that changes as the controller 113 proceeds through mode 302. One difference between methods 150 and 300 is that mode 302 includes a dry-cooled closed-loop chiller mode 310 in which the process fluid does not flow through the chiller evaporator 134 or the PCM tank 138 as indicated by reference numerals 312, 314. Instead, a secondary process fluid, which may be the same as or different from the process fluid flowing through the fluid cooling coil 116, is circulated by a closed-loop pump 140 as indicated by reference numeral 316. The closed-loop pump 140 sends the secondary process fluid between the chiller evaporator 134, which cools the secondary process fluid, and the PCM tank 138 to cool the phase change material within the PCM tank 138 and fill the PCM tank 138. The process fluid flows through the fluid cooling coil 116 in operating mode 310 to meet the heat load imposed on the heat transfer device 110.

[0041]

[0105] Similarly, in the adiabatic cooling and closed-loop chiller mode 316, the process fluid does not flow through the chiller evaporator 134 and the PCM tank 138 as indicated by reference numerals 318, 320. Instead, the secondary process fluid is circulated by the closed-loop pump 140, enabling the chiller evaporator 134 and the secondary process fluid to remove heat from the PCM tank 138 and fill the PCM tank 138. In the adiabatic cooling and closed-loop chiller mode 316, the process fluid is cooled via the fluid cooling coil 116 and an adiabatic pre-cooler 114 that pre-cools the air upstream of the fluid cooling coil 116.

[0042]

[0106] The operating mode 302 of method 300 includes a dry cooling and chiller mode 309 in which, as indicated by reference numeral 311, the chiller 130 operates and the process fluid flows through the chiller evaporator 134 and is cooled. Further, in the dry cooling and chiller mode 309, a portion of the cooled process fluid flows through the PCM tank 138 as indicated by reference numeral 313 to fill the PCM tank 138.

[0043]

[0107] The operating mode 302 includes a thermally insulated cooling mode 317 in which the chiller 130 is off. However, in the thermally insulated cooling mode 317, the process fluid cooled by the fluid cooling coil 116 flows into the PCM tank 138 to fill the PCM tank 138 as indicated by reference numeral 319. The operating mode 302 further includes a thermally insulated cooling and chiller mode 321 in which the process fluid cooled by the fluid cooling coil 116 and the chiller evaporator 134 is sent to the PCM tank 138 to fill the PCM tank 138 as indicated by reference numeral 323.

[0044]

[0108] Referring to FIGS. 7A and 7B, the controller 113 may utilize method 330 in response to receiving a request to minimize energy consumption and the PCM tank 138 being fillable. Method 330 includes an operating mode 332 in which the controller 113 proceeds in response to an increase in the heat duty 334 of the heat transfer device 110.

[0045]

[0109] Referring to FIG. 8, a heat transfer device 350, which is a second example of the above heat transfer device 10, is shown. The heat transfer device 350 is a process fluid heat exchange circuit 351 that receives a high-temperature process fluid from a cooling load 353 and cools the process fluid. For example, the process fluid heat exchange circuit 351 can return the cooled process fluid to the cooling load 353 at a process fluid set temperature. The heat transfer device 350 is similar to the heat transfer device 110 in many respects, except that it does not have a closed-loop pump and related valves for circulating the secondary process fluid in a closed loop to refill the PCM tank 368. The heat transfer device 350 includes a heat insulation pre-cooler 352 having an evaporative liquid distribution system 354 for distributing the evaporative liquid onto a pre-cooling pad 356 and a pump 358 of a sump 360 for sending the collected evaporative liquid back to the pre-cooling pad 356. The heat transfer device 350 further includes a fluid cooling coil 362, a fan 364, a chiller 366, and a PCM tank 368.

[0046]

[0110] With respect to FIGS. 9A and 9B, a method 380 that can be used in response to the controller 370 of the heat transfer device 350 receiving a request to minimize water consumption and the PCM tank 368 being drainable is shown. The method 380 includes a mode 382 in which the controller 370 proceeds according to logic 384 when the heat duty 386 changes between an initial or easy (388) level and a maximum or hard (390) level. The method 380 includes a variable 392 indicating the state of the components of the heat transfer device 350 that changes through various modes 382.

[0047]

[0111] With respect to FIGS. 10A and 10B, a method 400 that the controller 370 can execute in response to receiving a request to minimize energy consumption and the PCM tank 368 being drainable is shown. The method 400 includes a mode 402 in which the controller 370 proceeds according to logic 404 when the heat duty 406 of the heat transfer device 350 changes. The method 400 includes a variable 403 of the components of the heat transfer device 350 that changes according to various operating modes 402.

[0048]

[0112] Referring to FIGS. 11 and 11B, a method 410 that can be utilized by the controller 370 in response to receiving a request to minimize water consumption and the PCM tank 368 being fillable is shown. The method 410 has a mode 412 in which the controller 370 proceeds when the heat duty 414 of the heat transfer device 350 changes. The method 410 has a variable 415 of a component of the heat transfer device 350 that varies according to the various modes 412. One difference between the method 300 and the method 410 is that the method 410 fills the PCM tank 368 using the process fluid received from the cooling load 353 instead of utilizing a closed-loop circulation of the secondary process fluid. Thus, the cooling performed by the fluid cooling coil 362 and / or the chiller 366 is used for both cooling the process fluid and filling the PCM tank 368. The difference in operation is due to the absence of a closed-loop pump in the heat transfer device 350.

[0049]

[0113] With respect to FIGS. 12A and 12B, a method 420 that can be executed by the controller 370 in response to receiving a request to minimize energy consumption and the PCM tank 368 being fillable is shown. The method 420 includes an operation mode 422 in which the controller 370 switches when the heat duty 424 of the heat transfer device 350 changes. The method 420 includes a variable 426 of a component of the heat transfer device 350 that varies according to the different modes 422. In the method 420, the PCM tank 368 is filled using the process fluid in communication with the cooling load 353 instead of a closed-loop filling operation such as the method 330 described above.

[0050]

[0114] Referring to FIG. 13, a heat transfer device 430, which is a third example of the heat transfer device 10 described above, is shown. The heat transfer device 430 is similar to the heat transfer device 110 described above in many respects. The heat transfer device 430 has a process fluid heat exchange circuit 431 that can operate in various modes, for example, to cool the process fluid from the cooling load 433 and supply the process fluid to the cooling load 433 at a required process fluid set temperature.

[0051]

[0115] The heat transfer device 430 includes a secondary closed-loop pump 432 that promotes the filling of the PCM tank 438, and valves 434, 436, as will be described and considered in more detail below. The heat transfer device 430 includes a heat-insulated pre-cooler 440 having a pre-cooling pad 442, a sump 444, and a pump 446 that sends the collected evaporative liquid to the pre-cooling pad 442. The heat transfer device 430 further includes a fluid cooling coil 448, a fan 450, and a chiller 452 having a condenser 454 and an evaporator 456. The fan 450 is operable to draw air 458 across the pre-cooling pad 442 and the fluid cooling coil 448. The heat transfer device 430 includes a primary closed-loop pump 460 and valves 462, 464. The heat transfer device 430 has a controller 466 for operating the components of the heat transfer device 430 in various modes.

[0052]

[0116] For example, the controller 466 may operate the heat transfer device 430 in Mode 1, as shown in FIG. 14. The heat-insulated pre-cooler 440 is not shown in FIG. 14 to provide an unobstructed view. In Mode 1, the controller 466 operates the valves 470, 472, 474, 476 of the process fluid heat exchange circuit 431 to bypass the chiller 452 and the PCM tank 438. In Mode 1, the process fluid from the cooling load 433 is cooled only by heat exchange between the air flow across the fluid cooling coil 448 by the fan 450. In Mode 1, the heat-insulated pre-cooler 440 may operate to perform adiabatic cooling by lowering the dry bulb temperature of the air upstream of the fluid cooling coil 448 as needed.

[0053]

[0117] The heat transfer device 430 has Mode 2 shown in FIG. 15. In Mode 2, the valve 470 receives the process fluid at the inlet 470A, and the valve 470 adjusts the flow or the process fluid through it such that a portion of the process fluid is directed to the condenser 454 of the chiller 452 and the remaining process fluid is bypassed around the condenser 454. The valve 472 receives the process fluid heated at the inlet 472A from the condenser 454 and the process fluid from the cooling load 433 at the inlet 472B. The valve 472 combines the process fluid flows at the outlet 472C that supplies the mixed process fluid to the fluid cooling coil 448. The valve 470 may be adjusted to direct more or less process fluid to the condenser 454 as necessary to facilitate sufficient cooling by the evaporator 456 of the chiller 452.

[0054]

[0118] The adiabatic pre-cooler 440 may be operated as needed to lower the dry bulb temperature of the air upstream of the fluid cooling coil 448. The fluid cooling coil 448 exchanges heat between the process fluid and the air stream to supply the cooled process fluid to the valve 474. The valve 474 regulates the flow of the process fluid between the outlets 474B and 474C. The outlet 474C directs the cooled process fluid to the evaporator 456 of the chiller 452 that further cools the process fluid. The process fluid from the outlet 474B reaches the valve 476 after bypassing the evaporator 456 and the PCM tank 438. The valve 476 combines the flow of the process fluid received at the inlets 476A and 476B into the flow that moves from the outlet 476C of the valve 476 to the cooling load 433. Thus, a portion of the cooling load is addressed by the fluid cooling coil 448 (and the adiabatic pre-cooler 440 as needed), and a portion of the cooling load is addressed by the chiller 452. Mode 2 may be used as a way to meet the cooling duty required by the heat transfer device 430 in high load or high ambient air temperature situations and / or when the PCM tank 438 is completely discharged. Mode 2 may also be used to conserve water by providing cooling capacity to reduce the cooling load required for the adiabatic pre-cooler 440 and the fluid cooling coil 448 using the chiller 452. More specifically, Mode 2 can reduce the speed of the fan 450, thereby reducing the rate of moisture evaporation from the pad or other insulating medium of the adiabatic pre-cooler 440.

[0055]

[0119] With respect to FIG. 16, the controller 466 may operate the heat transfer device 430 in mode 3 where valves 470, 480 divert the process fluid flow around the chiller 452. Valve 474 directs a portion of the process fluid from the fluid cooling coil 448 to the PCM tank 438, and the remaining portion of the process fluid bypasses the PCM tank 438. Thus, in mode 3, a portion of the cooling load 433 is handled by the fluid cooling coil 448 and the adiabatic pre-cooler 440 as needed, and a portion of the cooling load 433 is handled by the discharge of the PCM tank 438. Mode 3 may be used in very high cooling load situations, high ambient air temperature situations, and / or to conserve energy and / or water by reducing the load on the fluid cooling coil 448, the fan 450, and the adiabatic pre-cooler 440.

[0056]

[0120] With respect to FIG. 17, the controller 466 may operate in mode 4 where valve 470 directs at least a portion of the process fluid from the cooling load 433 to the condenser 454 of the chiller 452. Valve 474 adjusts the process fluid flow such that a portion of the process fluid flows to the evaporator 456 of the chiller 452 and the remaining process fluid bypasses the chiller 452 and the PCM tank 438. Further, valves 482, 483 direct the process fluid from the evaporator 456 to the PCM tank 438, and valve 484 combines the cooled process fluid from the PCM tank 438 with the process fluid from the fluid cooling coil 448. In mode 4, a portion of the cooling load is handled by the fluid cooling coil 448 and optionally the adiabatic pre-cooler 440, a portion of the cooling load is handled by the chiller 452, and a portion of the cooling load is handled by the PCM tank 438. Mode 4 may be used as a way to meet the cooling duty requirements in high cooling load situations, high ambient air temperature situations, and / or to conserve water by reducing the load on the fluid cooling coil 448, the adiabatic pre-cooler 440, or to conserve energy by reducing the load on the fan 450.

[0057]

[0121] With respect to FIG. 18, in Mode 5 where there exists a first loop 490 of process fluid moving between the cooling load 433 and the fluid cooling coil 448 and a second loop 492 of closed-loop process fluid circulating between the evaporator 456 of the chiller 452 and the PCM tank 438 via the primary closed-loop pump 460, the heat transfer device 430 may be operated. The valve 470 passes the process fluid from the cooling load 433 to the condenser 454 so that the process fluid absorbs heat from the condenser 454 before moving to the fluid cooling coil 448. The fluid cooling coil 448 is used to absorb heat from both the cooling load 433 and the process of refilling the PCM tank 438. The adiabatic precooler 440 may be turned on in Mode 5 to enhance the cooling capacity of the fluid cooling coil 448 as needed. Mode 5 may be used to fill the completely or partially emptied PCM tank 438 while continuing to release heat from the cooling load 433.

[0058]

[0122] With respect to FIG. 19, in Mode 6 where the process fluid heat exchange circuit 431 has a primary closed loop 510 and a secondary closed loop 511 similar to the closed loop 492 of FIG. 18, the heat transfer device 430 may be operated by the controller 466. More specifically, the valves 502, 504 are closed with respect to the cooling load 433, and the secondary closed-loop pump 432 circulates the secondary closed-loop process fluid 500 between the condenser 454 of the chiller 452 and the fluid cooling coil 448 so that the fluid cooling coil 448 removes the heat added to the secondary closed-loop process fluid 500 by the condenser 454.

[0059]

[0123] In Mode 6, the primary closed-loop pump 460 circulates the secondary process fluid 512 between the evaporator 450 and the PCM tank 438 throughout the primary closed loop 510. In this way, the evaporator 450 removes heat from the primary closed-loop process fluid used to fill the PCM tank 438. Mode 6 may be used to refill the PCM tank 438 that is completely or partially empty when the heat transfer device 430 does not need to meet the cooling load 433, such as at night. The adiabatic precooler 440 may operate to increase the cooling capacity as needed.

[0060]

[0124] Referring to FIGS. 20A and 20B, the controller 466 may receive a request to minimize water consumption and utilize method 520 in response to the PCM tank 438 being drainable. Method 520 includes an operating mode 522 and logic 524 that the controller 466 uses to proceed through the operating mode 522 in response to a change in the heat duty 526 of the heat transfer device 430 determined by the controller 466. Method 520 has variables 528 of the components of the heat transfer device 430 that change when the heat transfer device 430 transitions between modes 522.

[0061]

[0125] Regarding FIGS. 21A and 21B, the controller 466 may receive a request to minimize energy consumption and utilize method 530 in response to the PCM tank 438 being drainable. Method 530 includes an operating mode 532 and logic 534 that the controller 466 uses to proceed through the operating mode 532 as the heat duty 536 of the heat transfer device 430.

[0062]

[0126] With respect to FIGS. 22A and 22B, the controller 466 may use method 540 in response to receiving a request to minimize water consumption, and the PCM tank 438 is fillable. Method 540 includes an operating mode 542 that the controller 466 may proceed to when the heat duty 544 of the heat transfer device 430 changes. Method 540 has a variable 545 of a component of the heat transfer device 530 that changes when the heat transfer device 530 transitions between modes 542. Mode 542 includes a closed-loop dry cooling mode 546 according to mode 6 of FIG. 19 when the adiabatic pre-cooler 440 is not operating. In one embodiment, the heat transfer device 430 includes an actuator that moves the adiabatic pre-cooler 440 from an operating position where the pads of the adiabatic pre-cooler 440 are within the airflow path through the heat transfer device 430 to a bypass position where the pads are outside the airflow path. When the pads are in the bypass position, the energy consumption of the fan 450 may decrease. The operating mode 542 further includes a closed-loop adiabatic cooling mode 548 corresponding to mode 6 of FIG. 19 when the adiabatic pre-cooler 440 is operating. In either mode 546 or 548, the heat transfer device 430 is isolated from the cooling load 433 and the PCM tank 438 can be filled.

[0063]

[0127] With respect to FIGS. 23A and 23B, the controller 466 may use method 550 in response to receiving a request to minimize energy consumption, and the PCM tank 438 is fillable. Method 550 includes a mode 552 that the controller 466 proceeds to when the heat duty 554 of the heat transfer device 430 changes. Method 550 includes a variable 556 of a component of the heat transfer device 430 that changes when the heat transfer device 430 is reconfigured between operating modes 552. The operating mode 552 includes a closed-loop adiabatic cooling mode 558 that generally corresponds to mode 6 of FIG. 19, and the adiabatic pre-cooler operates to improve the efficiency of the fluid cooling coil 448.

[0064]

[0128] With respect to FIG. 24, the heat transfer device 560 is a fourth example of the heat transfer device 10 of FIG. 1. The heat transfer device 560 is similar in structure and operation to the heat transfer device 350 described above. One of the differences is that the heat transfer device 560 includes a heat exchanger 562 having a direct heat exchanger 564 with an evaporative liquid distribution system 566 for distributing the evaporative liquid onto the fill 568, a sump 570 for collecting the evaporative liquid, and a pump 572 for returning the collected evaporative liquid to the fill 568. The heat transfer device 560 has a fan 574 that generates an air flow 576 with respect to the direct heat exchanger 554 such that when the evaporative liquid moves along the fill 568 and contacts the air flow 576, the evaporative liquid is cooled. The pump 572 transfers the cooled evaporative liquid from the sump 570 to the indirect heat exchanger 580 of the heat exchanger 562. The indirect heat exchanger 580 transfers heat between the evaporative liquid and a process fluid 582 received from a cooling load 584.

[0065]

[0129] With respect to FIG. 25, a heat transfer device 590, which is a fifth example of the heat transfer device 10 described above, is shown. The heat transfer device 590 is similar to the heat transfer device 560 described above. One of the differences between the heat transfer devices 560 and 590 is that the heat transfer device 590 has a direct heat exchanger 592 that directly transfers heat from a process fluid 594 received from a cooling load 596 to an air flow 598 generated by a fan 600. The direct heat exchanger 592 may include, for example, a fill sheet and / or a fill block. A trickle fill, a splash fill, or a fill-less approach may be used.

[0066]

[0130] Referring to FIG. 26, a heat transfer device 610 according to a second approach is shown. The heat transfer device 610 includes a heat exchanger 612 having an adiabatic precooler 614 with an adiabatic pad 616, and an indirect heat exchanger such as a fluid cooling coil 618. The heat transfer assembly 610 further includes a thermal energy storage such as a PCM tank 620 that performs the trim cooling required for the heat transfer device 610 to meet the heat load of the heat transfer device 610. The heat transfer device 610 has one or more air inlets 622, one or more air outlets 624, and a fan 626 operable to cause air to move across the precooling pad 616 and the fluid cooling coil 618 from the air inlet 622 to the air outlet 624.

[0067]

[0131] With respect to FIG. 27, a more detailed schematic view of the heat transfer device 610 is shown. The heat transfer device 610 is similar in many respects to the above-described heat transfer device 10 except that there is no chiller 28. The heat transfer device 610 includes an external structure such as a housing 630 that includes a heat exchanger 612, a process fluid distribution system 632, a controller 634, and a PCM tank 620. The PCM tank 620 contains a phase change material having a melting temperature above, for example, 65°F. The heat transfer device 610 has a process fluid inlet 636 for receiving a heated process fluid from a cooling load and a process fluid outlet 638 for returning the cooled process fluid to the cooling load.

[0068]

[0132] With respect to FIG. 28, the heat transfer device 640 is a first example of the heat transfer device 610 of FIG. 26. The heat transfer device 640 has a process fluid heat exchange circuit 641 for receiving a heated process fluid from a cooling load 654 and returning the cooled process fluid to the cooling load 654. The process fluid heat exchange circuit 641 includes an adiabatic precooler 642, a fluid cooling coil 644, a closed-loop pump 646, a PCM tank 648, and a controller 650. Since there is no chiller in the heat transfer device 640 such as the chiller 452 of FIG. 13, the heat transfer device 640 uses the adiabatic precooler 642 and the fluid cooling coil 644 to cool the process fluid from the cooling load 654 and also refill the PCM tank 648.

[0069]

[0133] With respect to FIG. 29, the heat transfer device 640 has a mode 1 in which the controller 650 operates the heat transfer device 640 such that the heated process fluid from the cooling load 654 moves to the fluid cooling coil 644 and returns to the cooling load 654 while bypassing the PCM tank 648. The adiabatic pre-cooler 642 may operate to lower the dry bulb temperature of the air in contact with the fluid cooling coil 644 and increase the cooling capacity of the heat transfer device 640 when the controller 650 is in mode 1.

[0070]

[0134] With respect to FIG. 30, the heat transfer device 640 has a mode 2 in which both the fluid cooling coil 644 and the PCM tank 648 handle the cooling load 654. The process fluid heat exchange circuit 641 includes a valve 660 that adjusts the flow of the process fluid from the fluid cooling coil 644 such that a portion of the process fluid moves to the PCM tank 648 and is cooled when the PCM tank 648 discharges. In this way, the PCM tank 648 may be discharged during peak heat loads to supplement the cooling performed by the fluid cooling coil 644. The adiabatic pre-cooler 642 may operate to lower the dry bulb temperature of the air in contact with the fluid cooling coil 644 and increase the cooling capacity of the heat transfer device 640 when the controller 650 is in mode 2.

[0071]

[0135] With respect to FIG. 31, the heat transfer device 640 has a mode 3 in which the valve 662 directs a portion 664 of the process fluid from the cooling load 654 to a valve 666 for mixing with the process fluid from the fluid cooling coil 644 and the PCM tank 648, thereby regulating the flow of the process fluid from the cooling load 654. In mode 3, an adiabatic pre-cooler 642 may be utilized to lower the temperature of the process fluid exiting the fluid cooling coil 644. Since the temperature of the process fluid from the fluid cooling coil 644 is low, the PCM tank 648 can be filled. The process fluid exiting the fluid cooling coil 644 and the PCM tank 648 is combined with the circulating process fluid 664 via the valve 666 such that the process fluid returning to the cooling load 654 still has the same return temperature as in mode 2. Mode 3 may be used when the fluid cooling coil 644 can significantly cool the process fluid depending on ambient and load conditions. The recirculation portion 664 of the process fluid is used to raise the temperature of the process fluid from the fluid cooling coil 664 and the PCM tank 648, ensuring that the process fluid is returned to the cooling load 654 at the required process fluid set temperature.

[0072]

[0136] With respect to FIG. 32, the heat transfer device 640 has a mode 4 in which the valves 670, 672 are closed with respect to the cooling load 654 and the closed-loop pump 646 operates to circulate the closed-loop fluid 674 between the fluid cooling coil 644 and the PCM tank 648 to refill the PCM tank 648. The adiabatic pre-cooler 642 may or may not be operating depending on specific circumstances. By not operating the adiabatic pre-cooler 642, the controller 650 reduces the water consumption of the heat transfer device 640. By operating the adiabatic pre-cooler 642 in mode 4, the controller 650 may minimize the energy consumption of the heat transfer device 640.

[0073]

[0137] With respect to FIG. 33, the controller 650 may use method 690 in response to receiving a request to minimize water consumption, and the PCM tank 648 is drainable. The controller 650 changes the operating mode 692 using logic 694 when the heat duty 696 of the heat transfer device 640 changes. Method 690 includes variable 698 of the components of the heat transfer device 640 that change when the controller 650 changes to various modes 692.

[0074]

[0138] With respect to FIG. 34, the controller 650 may use method 700, in which the PCM tank 648 is drainable, in response to receiving a request to minimize energy consumption. Method 700 includes an operating mode 702 and logic 704 used by the controller 650 to change mode 702 when the heat duty 706 of the heat transfer device 640 changes. Method 700 includes variable 708 of the heat transfer device 640 that changes when the controller 650 changes mode 702.

[0075]

[0139] With respect to FIG. 35, the controller 650 may use method 710 in response to receiving a request to minimize water consumption, and the PCM tank 648 is fillable. Method 710 includes a mode 712 that the controller 650 may change when the heat duty 714 of the heat transfer device 640 changes. Mode 712 includes a closed-loop dry cooling mode 716 similar to mode 4 shown in FIG. 32, in which the closed-loop pump 646 operates and the closed-loop fluid circulates between the fluid cooling coil 644 and the PCM tank 648 to refill the PCM tank 648. In the closed-loop dry cooling mode 716, the adiabatic precooler 742 is off. On the other hand, mode 712 includes a closed-loop adiabatic cooling mode 718 similar to mode 4 of FIG. 32 in which the adiabatic precooler 642 is operating.

[0076]

[0140] With respect to FIG. 36, the controller 650 may use a method 720 by which the PCM tank 648 is fillable in response to receiving a request to minimize energy consumption. The method 720 includes an operating mode 722 that the controller 650 may change in response to a change in the heat duty 724 of the heat transfer device 640. The method 720 includes a variable 726 of the heat transfer device 640 that changes when the heat transfer device 640 transitions between modes 722.

[0077]

[0141] With respect to FIG. 37, a heat transfer device 730, which is a second example of the heat transfer device 610 described above, is shown. The heat transfer device 730 is similar to the heat transfer device 640 in many respects, except that it does not have a closed-loop pump 646. The heat transfer device 730 includes a process fluid heat exchange circuit 731 having an adiabatic pre-cooler 732, a fluid cooling coil 734, a fan 736, and a PCM tank 741. The heat transfer device 730 has a controller 738 that operates the process fluid heat exchange circuit 731 to return the process fluid to a cooling load 740 at a specific process fluid variable such as temperature, flow rate, pressure, or a combination thereof. The PCM tank 741 removes heat from the process fluid when operating to meet maximum heat load conditions, reduce water consumption, or reduce energy consumption as needed.

[0078]

[0142] With respect to FIG. 38, the processor 738 may use a method 750 by which the PCM tank 740 is drainable in response to receiving a request to minimize water consumption. The method 750 includes a mode 752 and logic 754 that the controller 738 uses to change the mode 752 when the heat duty 756 of the heat transfer device 730 changes. The method 750 includes a variable 760 of a component of the heat transfer device 730 that changes when the heat transfer device 730 transitions between modes 752.

[0079]

[0143] With respect to FIG. 39, the controller 738 may use a method 770 by which the PCM tank 741 is drainable in response to receiving a request to minimize energy consumption. The method 770 includes an operating mode 772 of the heat transfer device 730 and logic 774 used by the controller 738 to change the operating mode 772 when the heat duty 776 of the heat transfer device 730 changes. The method 770 includes a variable 778 of a component of the heat transfer device 730 that changes when the controller 738 changes the mode 772.

[0080]

[0144] With respect to FIG. 40, the controller 738 may use a method 780 by which the PCM tank 741 is fillable in response to receiving a request to minimize water consumption. The method 780 includes an operating mode 782 that the controller 738 changes when the heat duty 784 of the heat transfer device 730 changes. The method 780 includes a variable 786 of a component of the heat transfer device 730 that changes when the heat transfer device 730 transitions between the modes 782.

[0081]

[0145] With respect to FIG. 41, the controller 738 may use a method 790 by which the PCM tank 748 is fillable in response to receiving a request to minimize energy consumption. The method 790 includes that the controller 738 has an adiabatic cooling mode 792 in which the sample pump 794 (see FIG. 37) of the adiabatic precooler 732 is on and the valve 796 directs at least a portion of the cooling process fluid to the PCM tank 741 to fill the PCM tank 741.

[0082]

[0146] With respect to FIG. 42, the heat transfer device 800 is a third example of the above heat transfer device 610. The heat transfer device 800 is similar to the above heat transfer device 640 except that it has a direct heat exchanger 802 for transferring heat between the air flow 804 generated by the fan 806 and the evaporative liquid. The evaporative liquid is collected and passes through the indirect heat exchanger 808, and heat is transferred between the process fluid received from the cooling load 810 and the evaporative fluid of the direct heat exchanger 802.

[0083]

[0147] With respect to FIG. 43, the heat transfer device 810 is a fourth example of the above-described heat transfer device 610. The heat transfer device 810 is similar to the heat transfer device 640, except that it has a direct heat exchanger 812 for transferring heat between the air flow 814 generated by the fan 816 and the process fluid received from the cooling load 818.

[0084]

[0148] With respect to FIG. 44, a heat transfer device 850 according to a third approach of the present disclosure is shown. The heat transfer device 850 includes a housing 851 having one or more air inlets 854, one or more air outlets 857, and one or more fans 859 for generating an air flow 859 from the air inlet 854 to the air outlet 856. The air inlet 854 includes a primary louver 856 and a secondary louver 858 that can be selectively closed to restrict the path of the air flow through the heat transfer device 850. For example, the primary louver 856 may be closed and the secondary louver 858 may be opened to divert air around the membrane vacuum dehumidification system 860.

[0085]

[0149] The heat transfer device 850 has one or more dehumidifiers such as a membrane vacuum dehumidification system 860 for removing moisture from the air flow in the area 862 upstream of the adiabatic pre-cooler 864 having a pre-cooling pad 866. The heat transfer device 850 has a heat exchanger such as a fluid cooling coil 868 downstream of the pre-cooling pad 866. The membrane vacuum dehumidification system 860 removes moisture from the air and lowers the air wet-bulb temperature. The pre-cooling pad 866 cools the air upstream of the fluid cooling coil 868 and lowers the air dry-bulb temperature to be very close to the air wet-bulb temperature. The dry cooling air in contact with the fluid cooling coil 868 results in more efficient heat transfer between the air flow 859 and the fluid cooling coil 868.

[0086]

[0150] With respect to FIG. 45, the heat transfer device 880 is a first example of the heat transfer device 850 of FIG. 44. The heat transfer device 880 includes a primary louver 882, a secondary louver 884, and a process fluid cooling system 881. The process fluid cooling system 881 includes a membrane vacuum dehumidification system 886, an adiabatic pre-cooler 888, a fluid cooling coil 890, and a fan 892. The heat transfer device 880 further includes a vacuum pump 894 of the membrane vacuum dehumidification system 886 and a controller 896 for controlling the operation of the heat transfer device 880. The adiabatic pre-cooler 888 includes a pre-cooling pad 900, an evaporative liquid distribution system 902, a sump 904, and a sump pump 906. The heat transfer device 880 includes a water collection system 910 having a condensate pump 912 that guides the water collected and condensed from the membrane vacuum dehumidification system 886 to the sump 904. In this way, the heat transfer device 880 may utilize at least a portion of the water collected from the membrane vacuum dehumidification system 886 as makeup water for the sump 904, thereby reducing the water consumption of the heat transfer device 880. The fluid cooling coil 890 receives a high-temperature process fluid from the cooling load 916 and returns the cooled process fluid to the cooling load 916. The fan 892 is operable to direct air along a first path 920 when the primary louver 882 is open and the secondary louver 884 is closed. When the primary louver 882 is closed and the secondary louver 884 is open, operating the fan 892 causes air to enter from the secondary louver 884 along a second path 922. The membrane vacuum dehumidification system 886 and the adiabatic pre-cooler 888 may be selectively operated to increase the heat transfer efficiency between the fluid cooling coil 890 and the airflow passing through the heat transfer device 880.

[0087]

[0151] With respect to FIGS. 46 to 50, the heat transfer device 880 is shown in various modes, and various cooling capabilities of the heat transfer device 880 in various modes are shown. With respect to FIG. 46, the heat transfer device 880 is in mode 1 in which the primary louver 882 is open, the secondary louver 920 is closed, the membrane vacuum dehumidification system 886 is operating, the adiabatic pre-cooler 888 is operating, and the fluid cooling coil 890 is transferring heat between the airflow and the process fluid from the cooling load 916.

[0088]

[0152] With respect to FIG. 47, the heat transfer device 880 is in Mode 2 where the primary louver 882 is closed and the secondary louver 884 is open so that the air flow bypasses the membrane vacuum dehumidification system 886. The air passes through the precooling pad 900 along the second flow path 922 and moves to the fluid cooling coil 890. In Mode 2, the adiabatic precooler 888 operates so that the precooling pad 900 lowers the dry bulb temperature of the air flow upstream of the fluid cooling coil 890.

[0089]

[0153] With respect to FIG. 48, the heat transfer device 880 is in Mode 3 where the primary louver 882 is closed, the secondary louver 884 is open, and air enters the heat transfer device 880 along the second flow path 922 and bypasses the membrane vacuum dehumidification system 886. In Mode 3, the sump pump 906 is off so that the evaporative liquid distribution system 902 does not direct liquid onto the precooling pad 900. Thus, the air in the area 930 upstream of the fluid cooling coil 890 has the same wet bulb temperature and dry bulb temperature as the ambient air. Mode 3 may be used when the heat transfer device 880 has a low cooling load or when the heat transfer device 880 is operating to minimize energy consumption.

[0090]

[0154] With respect to FIG. 49, the heat transfer device 880 is in Mode 4 where the primary louver 882 is open and the secondary louver 884 is closed. The fan 892 draws air into the heat transfer device 880 along the first flow path 920. The membrane vacuum dehumidification system 886 operates to lower the humidity of the air upstream of the precooling pad 900. The adiabatic precooler 888 is off so that the air flow has approximately the same wet bulb temperature and dry bulb temperature before and after the precooling pad 900. Thus, in Mode 4, the heat transfer device 880 uses the membrane vacuum dehumidification system 886 to dry the air upstream of the fluid cooling coil 890. Mode 4 may be used when the heat transfer device 880 is operating to minimize water consumption.

[0091]

[0155] With respect to FIG. 50, the controller 896 may use a method 940 in response to receiving a request to minimize energy consumption. The heat transfer device 880 may switch its operating mode 942 when the heat duty 944 required by the heat transfer device 880 changes. The method 940 has a variable 946 of a component of the heat transfer device 880 that changes when the controller 896 changes the operating mode 942. The variable 946 may include a variable 947 indicating the operation of the condensate pump 912. In the operating mode 942, the condensate pump 912 is off to conserve energy.

[0092]

[0156] With respect to FIG. 51, the controller 896 may execute a method 950 in response to receiving a request to minimize water consumption. The heat transfer device 880 switches its operating mode 952 when the heat duty 954 of the heat transfer device 880 changes. The method 950 includes a variable 956 that changes when the heat transfer device 880 transitions between operating modes 952.

[0093]

[0157] In the method 950, the sample pump 906 is off when the heat transfer device 880 is in the dry cooling mode 958 for water conservation. On the other hand, when the heat duty increases and the controller 896 transitions to the adiabatic cooling and membrane vacuum dehumidification mode 960, the sample pump 906 operates to perform additional adiabatic cooling on the air and increase the cooling capacity of the heat transfer device 880.

[0094]

[0158] With respect to FIG. 52, controller 896 may execute method 960 in response to receiving a request to produce water via membrane vacuum dehumidification system 886. Method 960 includes a mode 962 in which controller 896 varies when the heat duty 964 of heat transfer device 880 changes. Method 960 includes a variable 966 representing the state of a component of heat transfer device 880 that changes when heat transfer device 880 transitions between operating modes 962. Variable 966 includes a variable 968 indicating whether condensate pump 912 is operating. Since controller 896 has received a request to produce water, condensate pump 912 is operating in both operating modes 962.

[0095]

[0159] With respect to FIG. 53, heat transfer device 980 is a second example of the above-described heat transfer device 850. Heat transfer device 980 includes a primary louver 982, a secondary louver 984, and a tertiary louver 986 that are selectively operable to bypass membrane vacuum dehumidification system 988, adiabatic precooler 990, or both as desired to select an operating mode. Membrane vacuum dehumidification system 988 includes a vacuum pump 992 that promotes dehumidification of air and a condensate pump 994 that sends water condensed and collected from membrane vacuum dehumidification system 988 to a sample 996 of adiabatic precooler 990. Adiabatic precooler 990 includes a liquid distribution system 998, a precooling pad 1000, and a sample pump 1002. Heat transfer device 980 further includes a controller 1004, a fan 1006, and a fluid cooling coil 1008 that receives process fluid from cooling load 1010.

[0096]

[0160] With respect to FIG. 54, the controller 1004 may execute method 1020 in response to receiving a request to minimize energy consumption. Method 1020 includes an operating mode 1022 in which the heat transfer device 980 can switch when the heat duty 1024 of the heat transfer device 980 changes. Method 1020 includes a variable 1026 indicating the state of the components of the heat transfer device 980 that change when the heat transfer device 980 transitions between modes 1022. Variable 1026 includes a variable 1028 indicating whether the tertiary louver 986 is open or closed. In method 1020, the tertiary louver 986 is closed regardless of which operating mode 1022 the controller 1004 is in.

[0097]

[0161] With respect to FIG. 55, the controller 1004 may execute method 1030 in response to receiving a request to minimize water consumption. Method 1030 includes an operating mode 1032 in which the heat transfer device 980 can transition when the heat duty 1034 changes. Method 1030 includes a variable 1034 of the heat transfer device 980 that changes when the controller 1004 transitions between operating modes 1032. The operating mode 1032 includes a dry cooling operating mode 1036 in which the primary louver 982 and the secondary louver 984 are closed and the tertiary louver 986 is open, as indicated by variables 1038, 1040, 1042. By closing the primary and secondary louvers 982, 984, air may bypass the membrane vacuum dehumidification system 988 and the adiabatic precooler 990 and instead contact the fluid cooling coil 1008 to remove heat from the process fluid from the cooling load 1010.

[0098]

[0162] With respect to FIG. 56, the controller 1004 may execute method 1050 in response to receiving a request to generate water from the membrane vacuum dehumidification system 988. Method 1050 includes operating modes 1052, 1054 that include a variable 1056 that changes when the controller 1004 switches between operating modes 1052, 1054. As indicated by variable 1058, the condensate pump 994 operates in any of the operating modes 1052, 1054.

[0099]

[0163] With respect to FIG. 57, the heat transfer device 1070 is a third example of the above-described heat transfer device 850. The heat transfer device 1070 is similar to the above-described heat transfer devices 880 and 980 in many respects. The heat transfer device 1070 includes a primary louver 1072 and a secondary louver 1074, and a fan 1076 that generates an air flow within the heat transfer device 1070. The heat transfer device 1070 further includes a membrane vacuum dehumidification system 1078, an indirect heat exchanger 1080 that transfers heat from the process fluid received from the cooling load 1082, and a direct heat exchanger 1084. The direct heat exchanger 1084 includes a filter 1086, a sump 1088, a liquid distribution system 1090, and a sump pump 1092. The sump pump 1092 circulates a secondary liquid through the indirect heat exchanger 1080 to receive heat from the process fluid of the cooling load 1082. The liquid distribution system 1090 distributes the heated secondary liquid, such as by spraying it onto the filter 1086. The secondary liquid is cooled by the air flow as it moves along the direct heat exchanger 1084. The cooled secondary liquid is then sent back from the sump 1088 to the indirect heat exchanger 1080 again.

[0100]

[0164] With respect to FIG. 58, the heat transfer device 1100 is a fourth example of the above-described heat transfer device 850. The heat transfer device 1100 is similar to the above-described heat transfer device 1070 in many respects. One of the differences is that the heat transfer device 1100 includes a direct heat exchanger 1102 that receives a process fluid from the cooling load 1104. The direct heat exchanger 1102 includes a process fluid distribution system 1108 that distributes the process fluid, such as by spraying it onto the filter 1110. The process fluid is cooled by the air flow passing through the direct heat exchanger 1102 and collected in the sump 1106. The direct heat exchanger 1102 has a sump pump 1108 that guides the cooled process fluid back to the cooling load 1104. The heat transfer device 1100 includes a fan 1120 that is operable to draw air through primary and secondary louvers 1122 and 1124 that can be selectively closed to control the flow of air through the heat transfer device 1100.

[0101]

[0165] Referring to FIGS. 59 and 60, a heat transfer device 1150 is shown having a process fluid heat exchange circuit 1152 that receives process fluid from a cooling load 1154 and cools the process fluid to a required temperature. The process fluid heat exchange circuit includes a chiller 1154 and a heat exchanger 1156. The heat exchanger exchanges heat between the process fluid and the ambient air. The heat exchanger 1156 may include an adiabatic pre-cooler and an indirect heat exchanger. The heat transfer device 1150 has a chiller-on mode shown in FIG. 59, in which a valve 1158 of the process fluid heat exchange circuit 1152 directs heat from the heat exchanger 1156 to the chiller 1154. The heat transfer device 1150 further includes a chiller-off mode shown in FIG. 60. In the chiller-off mode, the valve 1158 bypasses the process fluid around the chiller 1154. The chiller-off mode of FIG. 60 may be used when there is a low heat load on the heat transfer device 1150.

[0102]

[0166] Referring to FIG. 61, the heat transfer device 1170 includes a housing 1172 having an air inlet 1174, an air outlet 1176, and one or more fans 1178 for generating an air flow therebetween. The heat transfer device 1170 has a heat-insulated pre-cooler 1180 including a pre-cooling pad 1182, a finned coil 1184, and a condenser coil 1186 of a chiller 1188. The condenser coil 1186 and the evaporator 1190 of the chiller 1188 are inside the housing 1172. In one embodiment, the condenser coil 1186 is in the path of the air moving between the air inlet 1174 and the air outlet 1176. In some embodiments, the condenser coil 1186 may remove plumes by heating the moist air. Further, since the condenser coil 1186 and the evaporator 1190 are inside the housing 1172, the heat transfer device 1170 may have a compact configuration. The finned coil 1184 receives the hot process fluid from the return 1194 and guides the cooled process fluid to the valve 1196. The valve 1196 adjusts the flow of the cooled process fluid from the finned coil 1184 to the evaporator 1190. The evaporator 1190 further cools the process fluid and guides the cooled process fluid to the cooled process fluid supply 1200 along the conduit 1198. The valve 1196 may adjust the flow of the cooled process fluid from the finned coil 1184 such that some or all of the cooled process fluid from the finned coil 1184 moves to the evaporator 1190 or does not move at all. The chiller 1188 includes an expansion valve 1202 and a compressor 1204, uses a refrigerant to remove heat from the process fluid in the evaporator 1190, and transfers the heat to the air flow through the condenser coil 1186. The heat transfer device 1170 does not have a thermal energy storage.

[0103]

[0167] With reference to FIGS. 62 and 63, a heat transfer device 1220 is shown that includes a chiller 1224 and a heat exchanger 1226 that operate to cool process fluid from a cooling load 1228. The chiller 1224 includes an evaporator 1230, a condenser 1240, a compressor 1242, and an expansion valve 1244. The heat transfer device 1220 has a pump 1250 that circulates the process fluid from the cooling load 1228 through the condenser 1240, the heat exchanger 1226, the evaporator 1230, and back to the cooling load 1228. The heat transfer device 1220 has a chiller on mode shown in FIG. 62 in which the compressor 1242 circulates refrigerant between the evaporator 1230 and the condenser 1240 to facilitate heat transfer from the process fluid to the refrigerant in the evaporator 1230. In this way, the chiller 1224 further reduces the temperature of the process fluid from the heat exchanger 1226. The heat transfer device 1220 further includes a chiller off mode shown in FIG. 63 in which the compressor 1242 does not circulate refrigerant between the evaporator and the condenser 1240. On the other hand, the pump 1250 is operable to direct the process fluid from the cooling load 1228 to the heat exchanger 1226 while the process fluid moves through the condenser 1240 and the evaporator 1230.

[0104]

[0168] Referring to FIGS. 64 through 67, a heat transfer device 1300 is shown having a process fluid heat exchange circuit 1302 that includes a glycol chiller 1304, a pump 1306, a thermal energy storage such as an ice tank 1308, a heat exchanger 1310 such as a glycol / water heat exchanger, and a heat exchanger 1312 such as an air / water heat exchanger. The heat exchanger 1310 is part of a water loop 1305 that receives warm water from a cooling load 1314. The heat exchanger 1310 transfers heat from the water loop 1305 to a glycol loop 1303.

[0105]

[0169] In FIG. 64, the heat transfer device 1300 is shown in a cooling load defrost mode where valve 1320 allows glycol to pass from the glycol chiller 1304 to the ice tank 1308, and valve 1322 guides the glycol from the ice tank 1308 to the glycol / water heat exchanger 1310. The glycol chiller 1304 and the ice tank 1308 remove heat from the glycol circulating within the glycol loop 1303, and heat is absorbed from the water within the water loop 1305 via the heat exchanger 1310.

[0106]

[0170] Regarding FIG. 65, the heat transfer device 1300 is shown in a cooling load ice making mode. More specifically, valve 1322 blocks the flow of glycol from the ice tank 1308 to the heat exchanger 1310 such that the glycol chiller 1304 removes heat from the glycol loop 1303 and returns the cooled glycol to the ice tank 1308 at a temperature lower than the storage temperature of the ice tank 1308, for example 32°F, thereby producing ice in the ice tank 1308. On the other hand, the water loop 1305 includes a pump 1330 that enables water from the cooling load 1314 to flow to the heat exchanger 1312 and be cooled. The cooling load ice making mode of FIG. 65 may be used when the heat load of the heat transfer device 1300 decreases, such as at night.

[0107]

[0171] Regarding FIG. 66, the heat transfer device 1300 is shown in a cooling load chiller and ice tank bypass mode. Valves 1320, 1322 block the flow of glycol through the glycol loop 1303. The pump 1330 circulates water between the cooling load 1314 and the heat exchanger 1312 to enable the heat exchanger 1312 to cool the water. The cooling load chiller and ice tank bypass mode of FIG. 66 may be used to save energy or when the heat load of the heat transfer device 1300 is low.

[0108]

[0172] With reference to FIG. 67, the heat transfer device 1300 is shown in the cooling load ice tank bypass mode. More specifically, the valve 1320 blocks the flow of glycol to the ice tank 1308. Instead, the glycol is circulated from the glycol chiller 1304 to the heat exchanger 1310 by the pump 1306. Thereby, the cooling performed by the glycol chiller 1304 may be utilized to cool the water in the water loop 1305 when water passes through the heat exchanger 1310.

[0109]

[0173] With reference to FIGS. 68 and 69, a heat transfer device 1350 similar to the heat transfer device 1170 is shown. The heat transfer device 1350 includes a housing 1352, an insulated precooler 1353 having a precooling pad 1354, a finned coil 1356, and a condenser coil 1358, and an evaporator 1360 of a chiller 1362. With reference to FIG. 69, the heat transfer device 1350 is shown in a perspective view to show that the heat transfer device 1350 is provided with a heat energy storage such as an ice tank 1370 alongside the evaporator 1360 of the chiller 1362.

[0110]

[0174] With reference to FIGS. 70 to 73, a heat transfer device 1390 having a chiller 1392, a heat energy storage such as a PCM tank 1394, and a heat exchanger 1396 for cooling a process fluid from a cooling load 1398 is shown. The PCM tank 1394 contains a phase change material having a storage temperature higher than 50°F (e.g., 65°F) so that the same process fluid can be used in the first and second fluid loops 1411, 1413 of the heat transfer device 1390 (see FIG. 71). The storage temperature may refer to the melting temperature or freezing temperature of the phase change material. The melting temperature and the freezing temperature may be the same or different depending on the phase change material. Examples of phase change materials that can be used include PureTemp 18 of PureTemp LLC and BioPCM®-Q18 of Phase Change Solutions, Inc.

[0111]

[0175] With respect to FIG. 70, the heat transfer device 1390 is shown in a cooling load PCM discharge mode where valve 1400 allows the process fluid to pass from the chiller 1392 to the PCM tank 1394, and valve 1402 guides the cooled process fluid from the PCM tank 1394 to the cooling load 1398. Valve 1404 guides the process fluid from the heat exchanger 1396 to the chiller 1392. In this way, the chiller 1392 and the PCM tank 1394 cool the process fluid to a temperature below the temperature of the process fluid output from the heat exchanger 1396.

[0112]

[0176] With respect to FIG. 71, the heat transfer device 1390 is shown in a cooling load PCM filling mode. In this mode, valves 1402, 1404 enable the pump 1410 to circulate the secondary process fluid between the chiller 1392 and the PCM tank 1394 within the first fluid loop 1411. The chiller 1392 outputs the secondary process fluid at a temperature lower than the freezing temperature of the PCM in the PCM tank 1394 to refill the PCM tank 1394. Further, in the cooling load PCM filling mode of FIG. 71, the heat transfer device 1390 can provide cooling capacity to the cooling load 1398 by the pump 1414 circulating the primary process fluid between the heat exchanger 1396 and the cooling load 1398 within the second fluid loop 1413.

[0113]

[0177] With respect to FIG. 72, the heat transfer device 1390 is shown in a cooling load PCM bypass tank mode. More specifically, valve 1400 bypasses the process fluid received from the chiller 1392 around the PCM tank 1394 and guides the process fluid to the cooling load 1398. Further, valve 1404 enables the process fluid from the heat exchanger 1396 to move to the chiller 1392.

[0114]

[0178] With respect to FIG. 73, the heat transfer device 1390 is shown in a cooling load chiller and PCM tank bypass mode. More specifically, in the mode of FIG. 73, valves 1402, 1404 are closed to bypass the process fluid around the chiller 1392 and the PCM tank 1394.

[0115]

[0179] With reference to FIGS. 74 through 76, a heat transfer device 1430 is shown that is similar in many respects to the above-described heat transfer device 1150. One difference between heat transfer devices 1150 and 1430 is that heat transfer device 1430 has a valve 1432 between heat exchanger 1434 and cooling load 1436 and a valve 1438 between heat exchanger 1434 and PCM tank 1440. Another difference between heat transfer devices 1150 and 1430 is that heat transfer device 1150 uses trim chiller 1154 to perform trim cooling, whereas heat transfer device 1430 uses PCM tank 1440 to perform trim cooling.

[0116]

[0180] Heat transfer device 1430 has a cooling load and PCM discharge mode shown in FIG. 74, a cooling load and PCM filling mode shown in FIG. 75, and a cooling load and PCM tank bypass mode shown in FIG. 76. In the mode of FIG. 75, valve 1432 may adjust the flow of process fluid from cooling load 1436 to return a portion of the process fluid to cooling load 1436 and mix it with the cooled process fluid from PCM tank 1440. PCM tank 1440 has a storage temperature higher than 70°F, for example 78°F. The mode of FIG. 75 uses recirculation of the process fluid to raise the temperature of the process fluid before the process fluid is returned to cooling load 1436.

[0117]

[0181] The heat transfer devices contemplated herein may take various shapes. In some embodiments, the components of the heat transfer device are packed into a single housing. In other embodiments, the components may be in a stand-alone structure that is operably connected. For example, FIG. 77 shows a heat transfer device 1450 that includes two stacked air / process fluid heat exchangers 1452, 1454 and a separate thermal energy storage 1456.

[0118]

[0182] With reference to FIG. 78, a heat transfer device 1460 is shown comprising a housing 1462 having an air inlet 1464, an air outlet 1466, and one or more fans 1468 operable to generate an air flow between the air inlet 1464 and the air outlet 1466. The heat transfer device 1460 comprises an adiabatic pre-cooler 1470 having a pre-cooling pad 1472 and an indirect heat exchanger such as a finned coil 1474. The finned coil 1474 receives a hot process fluid via a return 1476. The heat transfer device 1460 comprises a valve 1480 for regulating the flow of the cooled process fluid from the finned coil 1474 to a heat energy storage such as a PCM tank 1482. The process fluid may move from the valve 1480 to the PCM tank 1482 and then be returned to a cooled process fluid supply 1484 downstream of the valve 1480. The PCM tank 1482 is within the interior 1486 of the housing 1462 and in some embodiments may advantageously allow the air flow generated by one or more fans 1468 to cool the PCM tank 1482.

[0119]

[0183] With reference to FIG. 79, a heat transfer device 1500 is shown having a process fluid heat exchange circuit 1502 comprising a dehumidifier such as a membrane mass exchanger 1504, a heat exchanger 1506 such as an air / process fluid heat exchanger, and a pump 1508. The membrane mass heat exchanger 1504 receives air 1510 and lowers the wet bulb temperature of the air before the air reaches the heat exchanger 1506. The heat exchanger 1506 receives a process fluid from a cooling load 1512. By dehumidifying the air upstream of the heat exchanger 1506, the operating efficiency of the heat exchanger 1506 can be increased.

[0120]

[0184] With reference to FIG. 80, a heat transfer device 1530 is shown that includes a housing 1532, a primary air inlet 1534 having a primary louver 1536, a secondary air inlet 1538 having a secondary louver 1540, and an air outlet 1542. The heat transfer device 1530 further includes a membrane mass exchanger 1550, an adiabatic pre-cooler 1552 having a pre-cooling pad 1554, and an indirect heat exchanger such as a finned coil 1556. The membrane mass exchanger 1550 may include a tubular or sheet-like membrane that allows water vapor to pass through and be collected and removed from an air stream that dehumidifies the air upstream of the pre-cooling pad 1554. In a first mode, the secondary louver 1540 may be closed and the primary louver 1536 may be open such that air flows through the membrane mass exchanger 1550 to the pre-cooling pad 1554 and the finned coil 1556. Further, the heat transfer device 1530 has a second mode in which the primary louver 1536 is closed and the second louver 1538 is open such that air bypasses the membrane mass exchanger 1550 and moves through the second air inlet 1538 to the pre-cooling pad 1554. The finned coil 1556 receives a hot process fluid from a return 1570 and directs the cooled process fluid to a supply 1572 that leads the process fluid back to a cooling load.

[0121]

[0185] Regarding FIG. 81, a membrane mass exchanger 1660 is shown as an example of the above-described membrane mass exchanger 1550. The membrane mass exchanger 1660 includes an array of an air passage 1662, a sheet membrane 1664, and a permeation passage 1666. Air moves in direction 1670 and enters an air inlet 1669, moves along the air passage 1662 while contacting the sheet membrane 1664, and exits the air passage 1662 through an outlet 1672. The membrane mass exchanger 1660 includes a compressor or a vacuum pump 1682 that operates to create a vacuum in the permeation passage 1666. The presence of a vacuum in the permeation passage 1666 on the side of the sheet membrane 1664 opposite to the air passage 1662 draws water vapor in the air stream through the sheet membrane 1664 into the permeation passage 1666. The water vapor collected in the permeation passage 1666 moves through a conduit 1680 to the vacuum pump 1682 and a water output 1684. The water output 1684 includes, for example, an air moisture separator and a condenser that condenses the collected water vapor into liquid water for sending it to an adiabatic pre-cooler 1552 or another process. The condenser includes, for example, a cooled metal surface.

[0122]

[0186] Referring to FIG. 82, a heat transfer device 1700 is shown that includes an air inlet 1702, a dehumidifier 1704 such as a membrane mass exchanger 1706, an adiabatic pre-cooler 1708 having a pre-cooling pad 1710, an indirect heat exchanger such as a tube fin heat exchanger 1712, a direct heat exchanger such as a filter 1714, a plenum 1716, and an air outlet 1718 having a fan 1720. The fan 1720 generates an air stream from the air inlet 1702 to the air outlet 1718. The dehumidifier 1704 includes a liquid desiccant supply section 1730 having a pump 1732 that sends the liquid desiccant collected from a sump 1734 to the membrane mass exchanger 1706. Ambient air enters the air inlet 1702 such that the liquid desiccant in the membrane mass exchanger 1706 removes water vapor from the air. This reduces the wet bulb temperature of the air in region B.

[0123]

[0187] Next, the air passes through the pre-cooling pad 1710 that is wetted with water from a liquid supply section 1750 having a pump 1754 that pumps water from a sump 1752. The water on the pre-cooling pad 1710 lowers the dry bulb temperature in region C.

[0124]

[0188] The dehumidified dry air then passes through the tube fin heat exchanger 1712, enters the inlet 1760 of the tube fin heat exchanger 1712 at a high temperature, and transfers heat to the process fluid that exits from the outlet 1762 of the tube fin heat exchanger at a low temperature.

[0125]

[0189] The liquid desiccant supply unit 1730 includes a liquid desiccant sump 1770 equipped with an electric heater that heats the liquid desiccant to refill the liquid desiccant that has collected water vapor in the membrane mass exchanger 1706. Alternatively or additionally, the liquid desiccant sump 1770 may utilize waste heat from manufacturing operations or the like to heat the liquid desiccant. The liquid desiccant supply unit 1730 further includes a pump 1780 that guides the liquid desiccant to the spray 1788 on the filter 1714. The air moves from region D to region E and absorbs heat from the liquid desiccant. The cooled liquid desiccant is then returned to the membrane mass exchanger 1706 by the pump 1732.

[0126]

[0190] Referring to FIG. 83, there is shown a heat transfer device 1800 having a process fluid heat exchange circuit 1802 with an indirect heat exchanger such as a fluid cooling coil 1804, a thermoelastic chiller such as a shape memory alloy (SMA) cooler 1806, and a thermal energy storage such as a PCM tank 1808 that operates to supply a process fluid to a cooling load 1810 at a required temperature, pressure, flow rate, or combination thereof. The SMA cooler 1806 has a condenser side 1812 and an evaporator side 1814. The PCM tank 1808 has a storage temperature of, for example, 65°F. The SMA cooler 1806 generates heat when deformed by compression and absorbs heat when the compression is released, and the SMA returns to its original shape as shown by the phase diagram 1820 of FIG. 84. The SMA cooler 1806 may have a first plurality of cassettes of SMA alloy on the condenser side 1812 that generate heat while contracting and a second plurality of cassettes of SMA alloy on the evaporator side 1814 that absorb heat while expanding. The SMA cooler 1806 has a valve system that operably reverses the first and second pluralities of cassettes of SMA alloy between the first plurality of cassettes on the condenser side 1812 and the second plurality of cassettes on the evaporator side 1814 when the SMA alloy of the first plurality of cassettes is fully contracted and the SMA alloy of the second plurality of cassettes is fully expanded. Thus, the SMA cooler 1806 may operate as a chiller to further lower the temperature of the process fluid from the fluid cooling coil 1804 before the process fluid is directed to the PCM tank 1804. It will be understood that the SMA cooler 1806 may be utilized in place of, or in addition to, the refrigerant-based chillers discussed herein in other embodiments discussed herein. The SMA cooler 1806 and other chillers discussed herein may have a unique embedded controller that communicates with the master controller of the heat transfer device.

[0127]

[0191] The use of the singular terms "a", "an", etc. is intended to include both the singular and plural unless otherwise indicated herein or clearly contradicted by the context. The terms "comprising", "having", "including", and "containing" are to be construed as open-ended terms. The phrase "at least one of" is intended to be construed in a disjunctive sense when used herein. For example, the phrase "at least one of A and B" is intended to include A, B, or both A and B.

[0128]

[0192] While particular embodiments of the invention have been illustrated and described, it will be understood that many variations and modifications will occur to those skilled in the art, and the invention is intended to cover all such variations and modifications that fall within the scope of the appended claims.

Claims

1. A heat transfer device, Process fluid inlet and Process fluid outlet and A process fluid heat exchange circuit connecting the process fluid inlet to the process fluid outlet, wherein the process fluid heat exchange circuit is configured to receive process fluid at a first temperature through the process fluid inlet and return process fluid at a second temperature lower than the first temperature through the process fluid outlet, the process fluid heat exchange circuit comprising a heat exchanger, a fan operable to bring an airflow into contact with the heat exchanger, and a mechanical cooler having a condenser and an evaporator, wherein the heat exchanger receives process fluid from the condenser of the mechanical cooler and supplies the cooled process fluid to the evaporator, and the process fluid heat exchange circuit has a plurality of modes including a first mode in which the heat exchanger transfers heat between the process fluid and the airflow, and a second mode in which the heat exchanger transfers heat between the process fluid and the airflow and the evaporator of the mechanical cooler removes heat from the process fluid, A controller operably connected to the process fluid heat exchange circuit, configured to operate the process fluid heat exchange circuit in one of the plurality of modes, at least in part based on the determination of the thermal duty cycle of the heat transfer device, A heat transfer device equipped with the following features.

2. The heat transfer apparatus according to claim 1, wherein in the second mode, the process fluid heat exchange circuit guides at least a portion of the process fluid from the heat exchanger to the evaporator of the mechanical cooler so that the evaporator cools the at least portion of the process fluid from the heat exchanger.

3. The heat transfer apparatus according to claim 1, wherein in the second mode, the condenser of the mechanical cooler transfers heat to at least a portion of the process fluid, and the process fluid heat exchange circuit guides the at least portion of the process fluid to the heat exchanger so that the heat exchanger cools the at least portion of the process fluid from the condenser.

4. The heat transfer device according to claim 1, wherein the controller is configured to determine the thermal duty cycle based at least partially on the ambient air temperature.

5. The controller is configured to operate the process fluid heat exchange circuit in the first mode, at least partially based on the fact that the ambient air temperature is a first ambient air temperature, The heat transfer apparatus according to claim 4, wherein the controller is configured to operate the process fluid heat exchange circuit in the second mode, at least partially based on the fact that the ambient air temperature is a second ambient air temperature higher than the first ambient air temperature.

6. The heat exchanger comprises an adiabatic cooler that can operate in wet mode or dry mode when the process fluid heat exchange circuit is in the second mode, The heat transfer apparatus according to claim 5, wherein the controller is configured to operate the process fluid heat exchange circuit in the second mode and the adiabatic cooler in the wet mode, at least partially based on the fact that the ambient air temperature is a third ambient air temperature higher than the second ambient air temperature.

7. The thermal duty includes one of a plurality of thermal dutys, which include easier thermal duty and harder thermal duty. The controller is configured to operate the process fluid heat exchange circuit in the first mode, at least in part on the fact that the thermal duty cycle is easier than the thermal duty cycle. The heat transfer apparatus according to claim 1, wherein the controller is configured to operate the process fluid heat exchange circuit in the second mode, at least on the basis that the thermal duty cycle is a harder thermal duty cycle.

8. The heat transfer device according to claim 1, wherein the process fluid heat exchange circuit in the first mode is configured to cause the process fluid to bypass the mechanical cooler.

9. The process fluid heat exchange circuit comprises a valve located upstream of the mechanical cooler, The heat transfer apparatus according to claim 1, wherein the valve is configured to guide the process fluid away from the mechanical cooler when the process fluid heat exchange circuit is in the first mode.

10. The heat transfer apparatus according to claim 1, wherein the process fluid heat exchange circuit in the first mode is configured to guide the process fluid around at least one of the evaporator and the condenser of the mechanical cooler.

11. The heat transfer apparatus according to claim 1, wherein the mechanical cooler is not active when the process fluid heat exchange circuit is in the first mode.

12. The heat transfer device according to claim 1, wherein when the process fluid heat exchange circuit is in the first mode, the evaporator of the mechanical cooler is configured to remove less heat from the process fluid than when the process fluid heat exchange circuit is in the second mode.

13. The heat exchanger has a wet mode and a dry mode, The heat transfer apparatus according to claim 1, wherein the heat exchanger is capable of operating in either the wet mode or the dry mode when the process heat exchange circuit is in the second mode.

14. The heat exchanger comprises a coil, an insulating pad, and a liquid distribution system configured to distribute liquid to the insulating pad, The heat exchanger is capable of operating in either a wet mode or a dry mode when the process fluid heat exchange circuit is in the second mode. The heat transfer apparatus according to claim 1, wherein the liquid distribution system distributes more liquid to the heat insulating pad when the heat exchanger is in the wet mode than when it is in the dry mode.

15. The heat transfer apparatus according to claim 1, wherein the heat exchanger comprises an indirect heat exchanger and an adiabatic precooler.

16. The heat transfer apparatus according to claim 1, wherein the controller is configured to determine the thermal duty cycle at least in part on ambient air temperature, ambient air humidity, and / or process fluid temperature.

17. The heat transfer apparatus according to claim 1, wherein the mechanical cooler includes a chiller.

18. The heat transfer apparatus according to claim 1, wherein the process fluid heat exchange circuit includes one or more process fluid pumps.

19. The heat transfer device is combined with a cooling load, The process fluid inlet is connected to the cooling load so as to receive a high-temperature process fluid from the cooling load. The heat transfer apparatus according to claim 1, wherein the process fluid outlet is connected to the cooling load so as to return the cooled process fluid to the cooling load.

20. The controller is configured to receive a request to minimize either water consumption or energy consumption, The heat transfer apparatus according to claim 1, wherein the controller is configured to operate the process fluid heat exchange circuit in one of the plurality of modes, at least in part, based on the determination of the thermal duty cycle of the heat transfer apparatus and the requirement to minimize either water consumption or energy consumption.

21. Further comprising an external structure, The heat transfer apparatus according to claim 1, wherein the mechanical cooler and heat exchanger are located within the external structure.

22. The process fluid heat exchange circuit includes a thermal energy storage chamber, The aforementioned multiple modes are A third mode in which the heat exchanger is capable of operating to transfer heat between the process fluid and the airflow, and the heat energy storage is capable of operating to remove heat from the process fluid, A fourth mode in which the heat exchanger is operable to transfer heat between the process fluid and the airflow, the evaporator of the mechanical cooler is operable to remove heat from the process fluid, and the thermal energy storage is operable to remove heat from the process fluid, A heat transfer device according to claim 1, including the heat transfer device according to claim 1.

23. The controller is configured to determine the filling rate of the thermal energy storage facility. The heat transfer apparatus according to claim 22, wherein the controller is configured to operate the process fluid heat exchange circuit in one of the plurality of modes, at least in part, based on the determination of the thermal duty cycle of the heat transfer apparatus and the filling rate of the thermal energy storage.

24. The heat transfer apparatus of claim 22, wherein the process fluid heat exchange circuit has a fifth mode in which the heat exchanger is operable to transfer heat between the process fluid and the air, and the mechanical cooler is operable to fill the thermal energy storage.

25. The heat transfer apparatus of claim 24, wherein the process fluid heat exchange circuit in the fifth mode is configured to guide a closed-loop process fluid between the mechanical cooler and the thermal energy storage.

26. The process fluid heat exchange circuit in the fifth mode, The heat transfer apparatus according to claim 24, comprising a first process fluid closed loop, the first process fluid closed loop comprising the evaporator of the mechanical cooler, the heat energy storage chamber, and a first closed-loop pump for circulating a first process fluid between the evaporator and the heat energy storage chamber.

27. The heat transfer apparatus according to claim 24, wherein the process fluid heat exchange circuit has a sixth mode in which the heat exchanger and mechanical cooler can operate to fill the thermal energy storage.

28. The process fluid heat exchange circuit in the sixth mode, A first process fluid closed loop comprising the evaporator of the mechanical cooler, the heat energy storage chamber, and a first closed-loop pump for circulating a first process fluid between the evaporator and the heat energy storage chamber, The heat transfer apparatus according to claim 27, comprising a second process fluid closed loop, the condenser of the mechanical cooler, the heat exchanger, and a second closed-loop pump for circulating a second process fluid between the condenser and the heat exchanger.

29. The controller is configured to determine whether the thermal energy storage facility has a sufficient filling rate. The heat transfer apparatus according to claim 22, wherein the controller is configured to prevent the process fluid heat exchange circuit from being in the third mode or the fourth mode in response to the thermal energy storage not having the sufficient filling rate.

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