Abstract:
A cooling device with a subcooling system is disclosed, where the cooling device has a closed loop refrigerant cycle containing a refrigerant, including a heat exchanger communicating with the closed loop refrigerant cycle and communicating with a fluid, the heat exchanger configured to selectively receive and cool the refrigerant from the closed loop refrigerant cycle when the refrigerant temperature is greater than the coolant temperature; and a fluid receiving device configured to receive the fluid that is warmed in the heat exchanger. 
     A modular system for providing a refrigerant to a cooling device at an installation location is also disclosed and includes a transportable enclosure having at least one compressor, a condenser and a piping system for conveying the refrigerant in a closed loop cycle, where the piping system includes portions configured to be coupled to the cooling device at the installation location.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a cooling device. The present invention relates more particularly to a cooling device having a subcooling system. 
     BACKGROUND 
     It is well known to provide a cooling device such as a refrigerator, freezer, temperature controlled case, air conditioner, etc. that may be used in commercial, institutional and residential applications for storing refrigerated or frozen objects, or for providing cooling or air conditioning. Such known cooling devices often include a closed loop vapor expansion refrigeration cycle having a compressor, condenser, expansion device and an evaporator for transferring heat from an area or object to be cooled to a heat sink. In such known cooling devices, a condenser is provided to cool the compressed refrigerant, where it may then be expanded to a low temperature condition for absorbing heat in the evaporator. However, operational efficiencies in thermal performance of the cooling device may be realized by subcooling the liquid refrigerant before expansion to increase the heat absorption capability of the refrigerant in the evaporator. 
     In such known condensers for cooling systems, it is generally known to recover the waste heat in the condenser by circulating air or water to the condenser where the heat from the refrigerant warms the air or water, which may then be used in other applications such as heating an air supply or providing a source of hot water. However, these heat recovery applications are often limited to specific devices, such as heaters, radiators, defrost systems for the particular cooling device, etc. having fixed equipment located close to the cooling devices. 
     Accordingly, it would be advantageous to provide a cooling device with a subcooling system to improve the thermal performance of the cooling device. It would also be advantageous to provide a cooling device with a subcooling system that provides subcooling when a coolant is available and may be operated without subcooling when a coolant is unavailable. It would also be advantageous to provide a cooling device having a subcooling system that uses a readily available coolant, where the coolant can then be used as a source of heat in other applications. It would be further advantageous to provide a cooling device having a subcooling system that is portable and adaptable for use in a variety of locations. 
     Accordingly, it would be advantageous to provide a refrigeration device with a subcooling system having any one or more of these or other advantageous features. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is a schematic drawing of a cooling device with a subcooling system according to a preferred embodiment. 
     FIG. 1B is a schematic drawing of a cooling device with a subcooling system according to a preferred embodiment. 
     FIG. 2A is a schematic drawing of a cooling device with a subcooling system according to another preferred embodiment. 
     FIG. 2B is a schematic drawing of a cooling device with a subcooling system according to another preferred embodiment. 
    
    
     SUMMARY 
     The present invention relates to a cooling device with a subcooling system, where the cooling device has a closed loop refrigerant cycle containing a refrigerant, including a heat exchanger communicating with the closed loop refrigerant cycle and communicating with a fluid, the heat exchanger configured to receive and cool the refrigerant from the closed loop refrigerant cycle when the refrigerant temperature is greater than the fluid temperature; and a fluid receiving device configured to receive the fluid that is warmed in the heat exchange interface. 
     The present invention also relates to a method of subcooling a refrigerant in a cooling device having a closed loop cooling cycle, where the method includes connecting a heat exchanger to a condensed liquid refrigerant portion of the closed loop cooling cycle, providing a fluid from a fluid source in thermal communication with the heat exchanger, directing the refrigerant to the heat exchanger to cool the refrigerant and warm the fluid when the refrigerant temperature is greater than the fluid temperature, bypassing the refrigerant away from the heat exchanger when the refrigerant temperature is less than the fluid temperature, and routing the fluid from the heat exchanger to a fluid receiving device. 
     The present invention further relates to a cooling system having a subcooling device, with the cooling system having a refrigerant in a closed loop refrigeration cycle. A heat exchanger having a refrigerant inlet is configured to receive the refrigerant from the closed loop refrigeration cycle and a refrigerant outlet is configured to return the refrigerant in a cooled state to the closed loop refrigeration cycle. The heat exchanger further includes a fluid inlet configured to receive a fluid from a fluid source and a fluid outlet configured to discharge the fluid in a warmed state to a warm fluid usage application. A control system is also provided to direct the refrigerant through the heat exchanger when the refrigerant temperature at the refrigerant inlet is greater than the fluid temperature at the fluid inlet and to bypass the refrigerant around the heat exchanger when the refrigerant temperature is less than the coolant temperature. 
     The present invention also relates to a modular system for providing a refrigerant to a cooling device at an installation location, including a transportable enclosure having at least one compressor, a condenser and an interconnecting piping system for conveying the refrigerant in a closed loop cycle, where the piping system includes portions configured to be coupled to the cooling device at the installation location. 
     The present invention further relates to a modular subcooling unit adapted for use with a cooling device for subcooling a refrigerant and includes a heat exchanger adapted to selectively receive the refrigerant and adapted to receive a fluid, and a valve configured to direct the refrigerant to the heat exchanger when the valve is in a first position and to direct the refrigerant away from the heat exchanger when the valve is in a second position, and a control system configured to control the operation of the valve between the first position and the second position. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1A, a cooling device having a subcooling system is shown according to a preferred embodiment. Cooling device  10  (e.g. refrigerator, freezer, walk-in cooler, temperature-controlled case, air conditioner, chiller, etc.) includes the following conventional components: one or more compressors  12 , a condenser  14 , an expansion device  18 , an evaporator  20  and a refrigerant piping system  22  made of copper or other suitable material and interconnecting the components for conveying a vapor expansion refrigerant such as R-22, R-507 or R-404A in a closed-loop cycle. The cooling device may include other conventional components such as filters, dryers, oil separators, regulators, valves, sight glasses, etc. (not shown) that are suitable for a particular cooling system. In an alternative embodiment, the cooling device  10  may also include a receiver tank  16 , for applications where a receiver tank is desirable. The refrigerant in evaporator  20  receives heat from spaces or objects (not shown) to be cooled during the evaporation portion of the cycle and is then routed to compressor  12  where it is compressed to a high pressure and temperature state in the compression portion of the cycle. The refrigerant is routed to the condenser  14  where it is condensed to an approximate saturated liquid state and then received in receiver tank  16  (if provided). 
     The refrigerant leaving the condenser  14  and receiver  16  (if provided) is then expanded to a low pressure and temperature, saturated liquid and vapor mixture for use in the evaporator  20  to remove heat from an area or object to be cooled. The efficiency of the cooling system can be increased by subcooling the refrigerant. The use of a subcooler after the condensing operation may place the refrigerant in a saturated liquid state if not completely condensed in the condenser, and/or may lower the refrigerant temperature below its saturated liquid temperature to increase the relative percentage of saturated liquid resulting after the expansion process. 
     In a mode of operation without subcooling, the refrigerant may be routed through a valve  24  (e.g. solenoid valve, manual valve, etc.) directly to expansion device (e.g. throttle valve, capillary tube, etc.) for expansion to a low temperature state where it is available for removing heat in evaporator  20  to complete the cycle. In a mode of operation with subcooling, the refrigerant may be routed to a subcooling system  30  by closing valve  24  and directing the refrigerant through a subcooling supply line  32  to a subcooler  34  to subcool the refrigerant. The subcooled refrigerant leaving subcooler  34  may then be routed through subcooler return line  36  to expansion device  18 . 
     The cooling device with subcooling system may be provided as a complete system (as shown in FIG.  1 A), or may be provided as a generally self-contained modular unit for tie-in to a cooling device, or may further be provided as a modular system (as shown in FIG. 2A) capable of use at a desired installation location having a cooling device. In such applications, subcooling system  30  may be used to recover heat from the refrigerant for use in other applications where the availability of such heat is desirable or tolerable. 
     Referring further to FIG. 1A, the subcooling system is shown according to a preferred embodiment. Subcooling system  30  includes subcooler  34  provided between receiver  16  (if provided) or condenser  14  and expansion device  18  and includes a bypass line  38  that includes valve  24 . In a particularly preferred embodiment, subcooler  34  is a plate-type heat exchanger and includes inlet and outlet connections for both the refrigerant and a coolant in a counter-flow relation. The coolant is provided to subcooler  34  from a coolant source  40  through a coolant supply line  42 , where the coolant may be any steady flow or intermittent flow source of water or other coolant (e.g. a secondary loop liquid coolant for other devices such as a refrigeration device having both a primary vapor expanision loop and a secondary liquid cooling loop, etc.) having a temperature below the saturated liquid temperature of the refrigerant. When the coolant flow is available and has a temperature below the temperature of the liquid refrigerant, valve  24  closes and the liquid refrigerant is routed through subcooler  34 , and the subcooled refrigerant is then routed to expansion device  18  for expansion and use in evaporator  20  for cooling an area or object to be cooled. In an alternative embodiment, the subcooler can use any type of heat exchange device using any flow orientation. 
     In a particularly preferred embodiment, the coolant source  40  is a water supply such as a municipal, commercial, agricultural, residential or other supply source of relatively cold water. The coolant temperature increases as it travels through subcooler  34  and the warmed coolant that is discharged from subcooler  34  through subcooler discharge line  44  is then available for use in applications where a warm water supply is either desirable or tolerable. In a particularly preferred embodiment, the warmed coolant may be routed through a valve  48  to provide a supply of preheated water to a hot water device  46  (e.g. boiler, hot water heater, radiator, baseboard heaters, etc.) to provide a source  49  of hot water or steam. The warmed coolant may also be used for other applications, for example, valve  48  may be closed and valve  50  may be opened to direct the warmed coolant to other applications  52  where warm water is desirable, including, but not limited to, filling swimming pools, water theme parks, etc. or where warm water is tolerable, such as irrigating crops, plants or other agricultural products, watering lawns or landscapes, etc. According to other embodiments, subcooling system  30  may be used in applications  52  where a cooling device is used in a location where a water supply is required and warming of the water is either desirable or tolerable for its intended uses. 
     The coolant source  40  may involve applications where the coolant flow is intermittent, such as home or other residential uses, or where the coolant flow is generally steady or continuous such as commercial, industrial or agricultural uses. Where the application involves intermittent coolant flow rates, the coolant supply for subcooling is available whenever sufficient flow exists to maintain the coolant temperature at subcooler  34  below the liquid refrigerant saturation temperature, and improvements in thermal performance of cooling device  10  are available corresponding to the availability of coolant flow. Where the application involves a generally continuous or steady flow, the improvement in thermal performance of cooling device  10  is correspondingly increased. Accordingly, subcooling system  30  is capable of providing incremental thermal performance benefit in applications having low cooling demand or intermittent coolant flow, and subcooling system  30  is capable of providing a correspondingly greater thermal performance benefit in applications having large cooling demands and increased or continuous water flow demands. 
     Referring to FIGS. 1A and 1B, a control system for subcooling system  30  is provided according to a preferred embodiment. Control system  90  includes a sensor  92  (e.g. thermocouple, resistance temperature device (RTD), etc.) for monitoring the temperature of the liquid refrigerant downstream of receiver  16 , and a sensor  94  (e.g. thermocouple, RTD, etc.) for monitoring the temperature of the coolant supply to subcooler  34 . Sensors  92  and  94  provide a signal representative of the refrigerant supply temperature (T 1 ) for subcooler  34  and the coolant supply temperature (T 2 ) for subcooler  34  respectively to a control device  96 . When T 1  is greater than T 2 , control system  96  provides a signal to close valve  24  and direct the refrigerant flow through subcooler  34 . When T 1  is less than T 2 , control system  96  provides a signal to open valve  24  to bypass or divert the refrigerant flow around subcooler  34 . In an alternative embodiment, other cooling system parameters may be monitored or control system signals may be used to regulate the flow of coolant or refrigerant to the subcooler. 
     In another preferred embodiment, the subcooling system  30  may be provided as a generally self-contained modular unit (shown schematically as unit  31  adapted for use with an existing cooling device). Subcooling system  30 , including subcooler supply line  32 , heat exchanger  34 , subcooler return line  36 , bypass line  38 , valve  24 , sensor  92  and sensor  94 , may be provided as a modular unit sized for, and having suitable connections (not shown) for, tie-in to an existing cooling system and for receiving a supply of coolant. Unit  31  may be used for retrofitting existing cooling devices, or as a design alternative for new cooling devices, where the addition of a subcooling system is desirable. 
     Referring to FIG. 2A a cooling device  110  with a subcooling system  130  is provided as part of a modular system  60  according to a preferred embodiment. The modular system  60  is capable of installation at any location where a supply of cold refrigerant is desired and a coolant supply is available. An enclosure (e.g. trailer, van, container, skid, etc.) houses a compressor  112 , condenser  114 , suitable refrigerant piping  122 , and subcooler  134  and associated piping to provided a modular, mobile unit  62 . The cooling device  110  may be provided with a receiver  116  in a preferred embodiment, however, a receiver may be omitted in alternative embodiments. Refrigerant piping  122  in mobile unit  62  includes suitable refrigerant piping portions  82  such as flexible hoses with connectors or couplings  84  for coupling to existing refrigerant piping portions  86  having connections  88  at any appropriate installation location  80  such as a supermarket or other commercial, institutional, agricultural or industrial location. In a particularly preferred embodiment, the mobile unit  62  includes a hot water device  146  (e.g. hot water heater, boiler, etc.) for providing a source of hot water to installation location  80 . The hot water heater  146  receives a supply of warmed water from subcooler  34  to improve the thermal efficiency of hot water device  146  and to provide subcooling of the refrigerant for the cooling device. The mobile unit  60  has suitable supply piping  66  provided for connection to an external water supply source  140  to deliver a relatively cold supply of water to the coolant inlet of subcooler  134 , and piping  68  to deliver warmed water from the coolant outlet of subcooler  134  through valve  148  (with valve  150  closed) to hot water device  146 . Warmed water from subcooler  134  may also be directed to any other warmed water application  152  at installation location  80  by closing valve  148  and opening valve  150 . Suitable piping portions  72  such as flexible hoses and, connectors or couplings  74  for subcooling system  130  are provided to deliver the cold water from source  140  at installation location  80 , and to deliver the hot water from hot water device  146  to a receiving source  154 , and to deliver warmed water from subcooler  134  to a warm water application  152  at installation location  80 . 
     Referring to FIGS. 2A and 2B, a control system for subcooling system  130  is provided according to a preferred embodiment. Control system  190  includes a sensor  192  (e.g. thermocouple, resistance temperature device (RTD), etc.) for monitoring the temperature of the liquid refrigerant downstream of condenser  114  or receiver  116  if provided), and a sensor  194  (e.g. thermocouple, RTD, etc.) for monitoring the temperature of the coolant supply to subcooler  134 . Sensors  192  and  194  provide a signal representative of the refrigerant supply temperature (T 3 ) for subcooler  134  and the coolant supply temperature (T 4 ) for subcooler  134  respectively to a control device  196 . When T 3  is greater than T 4 , control system  196  provides a signal to close valve  124  and direct the refrigerant flow through subcooler  134 . When T 3  is less than T 4 , control system  196  provides a signal to open valve  124  to bypass or divert the refrigerant flow around subcooler  134 . 
     It is important to note that the construction and arrangement of the elements of the cooling device with subcooling system provided herein are illustrative only. Although only a few exemplary embodiments of the present invention have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible in these embodiments (such as variations in features such as components, coolant compositions, water supply sources, uses for the warmed water or devices for receiving the warmed water, orientation and configuration piping, location of components and sensors of the subcooling and control systems; variations in sizes, structures, shapes, dimensions and proportions of the components of the system, use of materials, colors, combinations of shapes, etc.) without materially departing from the novel teachings and advantages of the invention. For example, the cooling device with subcooling system, and the modular subcooling system, may be adapted for use in a wide variety of residential, commercial, institutional, industrial or agricultural applications, including supermarkets, food processing facilities, hotels, cold storage facilities, ice skating arenas, etc. and may be provided in any number, size, orientation and arrangement to suit a particular cooling system and hot water supply needs of the installation location. Further, it is readily apparent that variations of the subcooling system and its components and elements may be provided in a wide variety of types, shapes, sizes and performance characteristics, or provided in locations external or partially external to the refrigeration system. Accordingly, all such modifications are intended to be within the scope of the inventions. 
     The order or sequence of any process or method steps may be varied or resequenced according to alternative embodiments. In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating configuration and arrangement of the preferred and other exemplary embodiments without departing from the spirit of the inventions as expressed in the appended claims.