EP0485147A1 - Refrigeration system - Google Patents
Refrigeration system Download PDFInfo
- Publication number
- EP0485147A1 EP0485147A1 EP91310187A EP91310187A EP0485147A1 EP 0485147 A1 EP0485147 A1 EP 0485147A1 EP 91310187 A EP91310187 A EP 91310187A EP 91310187 A EP91310187 A EP 91310187A EP 0485147 A1 EP0485147 A1 EP 0485147A1
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- EP
- European Patent Office
- Prior art keywords
- evaporator
- conduit
- heat transfer
- refrigerant
- transfer arrangement
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B5/00—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity
- F25B5/04—Compression machines, plants or systems, with several evaporator circuits, e.g. for varying refrigerating capacity arranged in series
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B40/00—Subcoolers, desuperheaters or superheaters
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B1/00—Compression machines, plants or systems with non-reversible cycle
- F25B1/10—Compression machines, plants or systems with non-reversible cycle with multi-stage compression
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/05—Compression system with heat exchange between particular parts of the system
- F25B2400/052—Compression system with heat exchange between particular parts of the system between the capillary tube and another part of the refrigeration cycle
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/05—Compression system with heat exchange between particular parts of the system
- F25B2400/054—Compression system with heat exchange between particular parts of the system between the suction tube of the compressor and another part of the cycle
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/13—Economisers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/23—Separators
Definitions
- refrigerant In a typical refrigeration system, refrigerant circulates continuously through a closed circuit.
- circuit refers to a physical apparatus whereas the term “cycle” as used herein refers to operation of a circuit, e.g., refrigerant cycles in a refrigeration circuit.
- refrigerant refers to refrigerant in a liquid, vapor and/or gas form. Components of the closed circuit cause the refrigerant to undergo temperature/pressure changes. The temperature/pressure changes of the refrigerant result in energy transfer.
- Typical components of a refrigeration system include, for example, compressors, condensers, evaporators, control valves, and connecting piping. Details with regard to some known refrigeration systems are set forth in Baumeister et al., Standard Handbook for Mechanical Engineers, McGraw Hill Book Company, Eighth Edition, 1979, beginning at page 19-6.
- the present invention is believed to have greatest utility in refrigeration systems having more than one evaporator, such as a refrigeration system including a fresh food evaporator and a freezer evaporator. More particularly, one embodiment of the present invention comprises disposing a capillary tube, connected to the inlet of the freezer evaporator, in a heat transfer relationship with the freezer evaporator suction line, e.g., a conduit connected between the outlet of the freezer evaporator and the inlet of the compressor unit.
- a capillary tube connected to the inlet of the freezer evaporator, in a heat transfer relationship with the freezer evaporator suction line, e.g., a conduit connected between the outlet of the freezer evaporator and the inlet of the compressor unit.
- the first capillary tube 106 is disposed in a counterflow heat exchange arrangement with the conduits 120 and 130. Thermal contact is achieved, for example, by soldering the exterior of the capillary tube 106 and a portion of the exterior of the conduits 120 and 130 together side-by-side.
- the capillary tube 106 is shown as being wrapped around the conduits 120 and 130 as a schematic representation of a heat transfer relationship. The heat transfer occurs in a counterflow arrangement, i.e., the refrigerant flowing in the capillary tube 106 proceeds in a direction opposite to the flow of refrigerant in the conduits 120 and 130.
- FIGS 4A-B respectively, illustrate temperature-enthalpy diagrams.
- the diagram for Figure 4A is for a refrigeration circuit similar to the circuit 100 illustrated in Figure 1 but not having the capillary tube 122 and the conduit 130 disposed in a heat transfer configuration.
- the diagram in Figure 4B is for the refrigeration circuit 100 illustrated in Figure 1 which, as shown, includes one embodiment of the present heat transfer configuration, i.e., the capillary tube 122 and the conduit 130 are disposed in a heat transfer configuration.
- Figure 7 illustrates a third embodiment of a refrigeration system 400 including a third embodiment of the present heat transfer configuration.
- the refrigeration system 400 comprises a first compressor unit 402 and a second compressor unit 404, the outlet of the first compressor unit 402 being connected to the inlet of the second compressor unit 404.
- a first capillary tube 406 is coupled to the outlet of the second compressor unit 404, and the outlet of the first capillary tube 406 is coupled to the inlet of a first expansion device 408.
- the outlet of the first expansion device 408 is coupled to the inlet of the first evaporator 410, and the outlet of the first evaporator 410 is coupled to the inlet of a phase separator 412.
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Devices That Are Associated With Refrigeration Equipment (AREA)
Abstract
Description
- The present application is related to commonly assigned U.S. Patent Application Serial No. (RD-19,924) entitled "Refrigeration System And Refrigerant Flow Control Apparatus Therefor.
- The present invention generally relates to refrigeration systems and, more particularly, relates to heat transfer configurations for refrigeration systems including a plurality of evaporators and a compressor unit.
- In a typical refrigeration system, refrigerant circulates continuously through a closed circuit. The term "circuit", as used herein, refers to a physical apparatus whereas the term "cycle" as used herein refers to operation of a circuit, e.g., refrigerant cycles in a refrigeration circuit. The term "refrigerant", as used herein, refers to refrigerant in a liquid, vapor and/or gas form. Components of the closed circuit cause the refrigerant to undergo temperature/pressure changes. The temperature/pressure changes of the refrigerant result in energy transfer. Typical components of a refrigeration system include, for example, compressors, condensers, evaporators, control valves, and connecting piping. Details with regard to some known refrigeration systems are set forth in Baumeister et al., Standard Handbook for Mechanical Engineers, McGraw Hill Book Company, Eighth Edition, 1979, beginning at page 19-6.
- Energy efficiency is one important factor in the implementation of refrigeration systems. Particularly, an ideal refrigeration system provides an ideal refrigeration effect. In practice, an actual refrigeration system provides an actual refrigeration effect less than the ideal refrigeration effect. The actual refrigeration effect provided varies from system to system.
- Increased energy efficiency typically is achieved by utilizing more expensive and more efficient refrigeration system components, adding extra insulation adjacent to the area to be refrigerated, or by other costly additions. Increasing the energy efficiency of a refrigeration system therefore usually results in an increase in the cost of the system. It is desirable, of course, to increase the efficiency of a refrigeration system and minimize any increase in the cost of the system.
- In some apparatus utilizing refrigeration systems, more than one area is to be refrigerated, and at least one area requires more refrigeration than another area. A typical household refrigerator, which includes a freezer compartment and a fresh food compartment, is one example of such an apparatus. The freezer compartment preferably is maintained between -10° Fahrenheit (F) and +15°F, and the fresh food compartment preferably is maintained between +33°F and +47°F.
- To meet these temperature requirements, a typical refrigeration system includes a compressor coupled to an evaporator disposed within the household refrigerator. The terms "coupled" and "connected" are used herein interchangeably. When two components are coupled or connected, this means that the components are linked, directly or indirectly in some manner in refrigerant flow relationship. Another component or other components can be intervening between coupled or connected components. For example, even though other components such as a pressure sensor or an expander are connected or coupled in the link between the compressor and evaporator, the compressor and evaporator are still coupled or connected.
- Referring again to the refrigeration system for a typical household refrigerator, the evaporator is operated so that it is maintained at approximately -10°F (an actual range of approximately -30°F to 0°F typically is used) and air is blown across the coils of the evaporator. The flow of the evaporator-cooled air is controlled, for example, by barriers. A first portion of the evaporator-cooled air is directed to the freezer compartment and a second portion of the evaporator-cooled air is directed to the fresh food compartment. To cool a fresh food compartment, rather than utilizing evaporator-cooled air from an evaporator operating at -10°F, it is possible to utilize an evaporator operating at, for example, +25°F (or a range of approximately +15°F to +32°F). The typical refrigeration system utilized in household refrigerators, therefore, produces its refrigeration effect by operating an evaporator at a temperature which is appropriate for the freezer compartment but lower than it needs to be for the fresh food compartment.
- It is well-known that the energy required to maintain an evaporator at -10°F is greater than the energy required to maintain an evaporator at +25°F in a refrigerator. The typical household refrigerator therefore uses more energy to cool the fresh food compartement than is necessary. Using more energy than is necessary results in reduced energy efficiency.
- The above referenced household refrigerator example is provided for illustrative purposes only. Many apparatus other than household refrigerators utilize refrigeration systems which include an evaporator operating at a temperature below a temperature at which the evaporator actually needs to operate.
- Refrigeration systems which reduce energy use are described in commonly assigned U.S. Patent Nos. 4,910,972 and 4,918,942. The patented systems utilize at least two evaporators and a plurality of compressors or a compressor having a plurality of stages. For example, in a dual, i.e., two, evaporator circuit for household refrigerators, a first evaporator operates at +25°F and a second evaporator operates at -10°F. Air cooled by the first evaporator is utilized for the fresh food compartment and air cooled by the second evaporator is utilized for the freezer compartment. Utilizing the dual evaporator refrigeration system in a household refrigerator results in increased energy efficiency. Energy is conserved by operating the first evaporator at the temperature (e.g., +25°F) required for the fresh food compartment rather than operating an evaporator for the fresh food compartment at -10°F. Other features of the patented systems also facilitate increased energy efficiencies.
- To drive the plurality of evaporators in the refrigeration systems described in U.S. Patent Nos. 4,910,972 and 4,918,942, and as mentioned above, a plurality of compressors or a compressor including a plurality of stages are utilized. Utilizing a plurality of compressors or utilizing a compressor having a plurality of stages results in increasing the cost of the refrigeration system over the cost, at least initially, of refrigeration systems utilizing one evaporator and one single stage compressor.
- The refrigeration system described in U.S. Patent Application Serial No. (RD-19,924) provides improved energy efficiency achieved using a plurality of evaporators and minimizes, if not eliminates, the increase in cost associated with using a plurality of compressors or a compressor having a plurality of stages. Particularly, in one embodiment, the refrigeration system described in U.S. Patent Application Serial No. (RD-19,924) comprises a refrigerant flow control unit and a compressor unit. In the exemplification embodiment, the compressor unit is a single stage compressor. The refrigerant flow control unit is coupled to a plurality of input conduits. Each conduit, in the exemplification embodiment, has refrigerant disposed therein, and each respective refrigerant is at a respective pressure. For example, a first input to the control unit is a high pressure refrigerant and a second input to the control unit is a low pressure refrigerant. The outlet of the refrigerant flow control unit is coupled to the inlet of the compressor unit.
- In operation, the respective refrigerants are provided as inputs to the control unit as described above, and the control unit provides that each respective refrigerant flows, alternately, to the compressor unit. The refrigerant flow timing, i.e., the length of time each input refrigerant is allowed to flow to the compressor unit, is determined on a straight timed basis or in accordance with measurable physical attributes, such as the respective pressures, temperatures, densities, and/or flow rates of the respective refrigerants.
- In one circuit embodiment, when the freezer evaporator encounters thermal loads which are substantially below design load for example, some unevaporated liquid refrigerant is discharged from the freezer evaporator. The potential cooling capacity of the freezer evaporator, therefore, is decreased under these conditions, yet the amount of work required of the compressor unit is substantially unaffected.
- Some of the lost cooling capacity is regained by disposing the conduit, i.e., the suction line, connected to the outlet of the freezer evaporator in a heat transfer arrangement with the conduit connected to the outlet of the condenser. Refrigerant liquid exiting the condenser is further subcooled as a result of the heat transfer arrangement thereby decreasing the enthalpy of the refrigerant before expansion in the fresh food evaporator. This heat transfer effectively shifts the specific cooling capacity, i.e., [(mass flow) x (enthalpy change)], regain from the freezer evaporator to the fresh food evaporator.
- It is well known, however, that the mechanical energy required to provide mass low to the freezer evaporator is greater than the mechanical energy required to provide mass flow to the fresh food evaporator, i.e., more mechanical energy is required to operate an evaporator at a lower temperature. Although the above described heat transfer provides regain of cooling capacity, it would be most desirable if at least some of the cooling capacity regain is provided to the freezer evaporator, thereby decreasing the mechanical energy required to operate the freezer evaporator.
- It is an object of the present invention to improve the energy efficiency of a refrigeration system which includes a single compressor unit coupled, directly or indirectly, to a plurality of evaporators.
- Another object of the present invention is to provide regain of cooling capacity in an evaporator which operates at a low temperature in a refrigeration system.
- Still another object of the present invention is to decrease the mechanical eneryy required to operate a refrigeration system having a plurality of evaporators.
- The present invention is believed to have greatest utility in refrigeration systems having more than one evaporator, such as a refrigeration system including a fresh food evaporator and a freezer evaporator. More particularly, one embodiment of the present invention comprises disposing a capillary tube, connected to the inlet of the freezer evaporator, in a heat transfer relationship with the freezer evaporator suction line, e.g., a conduit connected between the outlet of the freezer evaporator and the inlet of the compressor unit.
- An exemplification refrigeration system having a plurality of evaporators includes a condenser coupled to the outlet of a compressor unit. In this embodiment, the compressor unit is a single-stage compressor. A first evaporator is coupled through a first expansion device to receive the refrigerant discharged from the condenser. The outlet of the first evaporator is coupled to a phase separator which separates refrigerant output from the first evaporator into liquid and vapor. A vapor outlet from the phase separator is coupled to a first inlet of a refrigerant flow control unit. The outlet of the refrigerant flow control unit is coupled to the inlet of the compressor unit. A liquid outlet from the phase separator is coupled to a second expansion device. In the exemplification embodiment, the second expansion device is a capillary tube. The outlet of the capillary tube is coupled to the inlet of a second evaporator. The outlet of the second evaporator is coupled to a second inlet of the refrigerant flow control unit.
- In accordance with the present invention, the capillary tube coupled to the inlet of the second evaporator is disposed in a heat transfer relationship with the conduit, i.e., the second evaporator suction line, connecting the outlet of the second evaporator to the second inlet of the refrigerant flow control unit. The capillary tube and the second evaporator suction line preferably are disposed in a counterflow heat exchange arrangement wherein refrigerant flowing in the capillary tube proceeds in a direction opposite to the low of refrigerant in the second evaporator suction line.
- In operation, the refrigerant flow control unit allows refrigerant received at its first and second inlets to alternately flow to the compressor unit. The compressor unit compresses each refrigerant flow to a same pressure. The refrigerant, or at least portions of the refriferant, circulates through the refrigeration system to bring about energy transfer. For example, the first evaporator operates between +15°F and +32°F in order to refrigerate the fresh food compartement to between +33°F and +47°F. The second evaporator operates between -30°F and 0°F in order to refrigerate the freezer compartement to between -10°F and +15°F.
- The heat exchange configuration between the capillary tube and the second evaporator suction line provides a specific cooling capacity increase, or regain, in the second evaporator. The term "specific" means "per unit mass low rate". The specific cooling capacity increase in the second evaporator also provides that less mechanical energy is required to operate the second evaporator at low temperatures.
- These and other objects of the present invention, together with further features and advantages thereof, will become apparent from the following detailed specification when read together with the accompanying drawings, in which:
- Figure 1 illustrates a first embodiment of a refrigeration system including a first embodiment of the present heat transfer configuration;
- Figure 2 illustrates, in more detail, the accumulator used in the embodiment of the refrigeration system illustrated in Figure 1;
- Figure 3 illustrates, in more detail, an embodiment of the refrigerant low control unit used in the embodiment of the refrigeration system illustrated in Figure 1;
- Figures 4A-B, respectively, illustrate temperature-enthalpy diagrams for a refrigeration circuit not having the present heat transfer configuration and for the refrigeration circuit illustrated in Figure 1 which includes the present heat transfer configuration, respectively;
- Figure 5 is a block diagram illustration of a household refrigerator;
- Figure 6 illustrates a second embodiment of a refrigeration system including a second embodiment of the present heat transfer configuration; and
- Figure 7 illustrates a third embodiment of a refrigeration system including a third embodiment of the present heat transfer configuration.
- The present invention, as described herein, is believed to have its greatest utility in refrigeration systems and particularly in household refrigerator/freezers. The present invention, however, has utility in other refrigeration applications such as multiple air conditioner units. The term refrigeration systems, as used herein, therefore not only refers to refrigerator/freezers but also to many other types of refrigeration applications.
- A
first embodiment 100 of a refrigeration system is shown in Figure 1. Thesystem 100 comprises acompressor unit 102 coupled to acondenser 104. A firstcapillary tube 106 is coupled to the outlet of thecondenser 104. Preferably, a filter/dryer 105, known in the art as a "pickle", is disposed in the refrigerant flow path between thecondenser 104 and thecapillary tube 106. Thepickle 105 filters out particulates from the refrigerant and absorbs moisture. Afirst evaporator 108 is shown coupled to the outlet of the firstcapillary tube 106. The outlet of thefirst evaporator 108 is coupled to the inlet of aphase separator 110. Thephase separator 110 includes ascreen 112 disposed adjacent the phase separator inlet, avapor portion 114 and aliquid portion 116. The phaseseparator vapor portion 114 is coupled, as a first input, to a refrigerantflow control unit 118. Aconduit 120 extends from the phaseseparator vapor portion 114 to thecontrol unit 118 and theconduit 120 is arranged within thephase separator 110 so that liquid refrigerant entering the phaseseparator vapor portion 114 passes through thevapor portion 114 and cannot enter the open end of theconduit 120. The outlet of the phaseseparator liquid portion 116 is coupled to a secondcapillary tube 122. Asecond evaporator 124 is coupled to the outlet of the secondcapillary tube 122, and the outlet of thesecond evaporator 124 is coupled, as a second input, to the refrigerantflow control unit 118. - The outlet of the refrigerant
flow control unit 118 is coupled to thecompressor unit 102. Athermostat 126, which receives current flow from an external power source designated by the legend "POWER IN" 128, is connected to thecompressor unit 102. When cooling is required, the thermostat output signal provides for activation of thecompressor unit 102. Thethermostat 126 typically is disposed in the freezer compartment of the refrigerator. Thecompressor unit 102 operates only when thethermostat 126 indicates a need for cooling. The configuration of thecontrol unit 118 dictates refrigerant flow through the respective evaporators as hereinafter described. - The
evaporators compressor unit 102 preferably is a rotary type compressor. Theevaporators Theevaporators - The subject matter of the present invention is specifically directed to the heat transfer configuration shown, as one embodiment, between the second
capillary tube 122 and theconduit 130, i.e., the suction line of thesecond evaporator 124. The secondcapillary tube 122 is disposed in a counterflow heat transfer arrangement with theconduit 130. More specifically, the secondcapillary tube 122 is in thermal contact with theconduit 130. Thermal contact is achieved, for example, by soldering the exterior of thecapillary tube 122 and a portion of theconduit 130 together side-by-side. Thecapillary tube 122 is shown as being wrapped around theconduit 130 as a schematic representation of a heat transfer relationship. As hereinbefore described, the heat transfer occurs in a counterflow arrangement, i.e., the refrigerant flowing in thecapillary tube 122 proceeds in a direction opposite to the flow of refrigerant in theconduit 130. As is well known in the art, using a counterflow heat exchange arrangement, rather than a heat exchange arrangement wherein the flows proceed in a same direction, increases the heat exchange efficiency. Further details with regard to the advantages obtained with the present heat transfer configuration are provided with respect to Figures 4A and B. It is contemplated that thecapillary tube 122, in another embodiment (not shown), is disposed so that the flows through thecapillary tube 122 and theconduit 130 proceed in the same direction. - The first
capillary tube 106 is disposed in a counterflow heat exchange arrangement with theconduits capillary tube 106 and a portion of the exterior of theconduits capillary tube 106 is shown as being wrapped around theconduits capillary tube 106 proceeds in a direction opposite to the flow of refrigerant in theconduits - In addition to the above components, the
system 100 includes anaccumulator 134. Theaccumulator 134 is disposed at the exit of thesecond evaporator 124 and within the freezer compartment. Apressure sensor 138 also is illustrated in Figure 1. Thepressure sensor 138 is disposed in a position to generate a signal representative of the pressure of refrigerant flowing in theconduit 120 and between thecapillary tube 106 and theconduit 120 heat exchange arrangement and thecontrol unit 118. The output signal from thepressure sensor 138 is used to control operation of thecontrol unit 118 as hereinafter described. - Referring now to Figure 2, a more detailed view of the
accumulator 134 is shown. Theaccumulator 134 receives refrigerant discharged from thesecond evaporator 124 and supplies vapor refrigerant to thecompressor unit 102, via thecontrol unit 118. An internal transportline bleeder hole 136 is provided to prevent lubricant hold-up when cycle conditions change, e.g., when superheated vapor is discharged from thesecond evaporator 124. - When the
second evaporator 124 operates at lower than specification temperatures, such as due to decreased thermal load or due to compartment thermostat setting for example, some liquid is discharged from thesecond evaporator 124. Theaccumulator 134 prevents a loss of cooling capacity which would result from evaporation, in theconduit 130, of liquid discharged from thesecond evaporator 124. Particularly, liquid discharged from thesecond evaporator 124 is stored in theaccumulator 134. Vapor discharged from thesecond evaporator 124 passes through theconduit 130. When refrigerant flowing from thesecond evaporator 124 is superheated, then the refrigerant liquid stored within theaccumulator 134 is evaporated in theaccumulator 134 and passes through theconduit 130. In this manner, theaccumulator 134 facilitates preventing a loss of the cooling capacity of thesecond evaporator 124. - The
flow control unit 118 is schematically shown in more detail in Figure 3. The twoinput conduits control unit 118. Theoutput conduit 132 also is shown integrally formed with thecontrol unit 118. Theinput conduits output conduit 132, rather than being integrally formed with theunit 118, in another embodiment (not shown) are coupled to inlets and an outlet, respectively, of theunit 118 such as by welding, soldering, mechanical couplers, etc. Thecontrol unit 118 includes acontrollable valve 140 which comprises a solenoid operated valve. A solenoid controlled valve is available, for example, from ISI Fluid Power Inc., Fraser, Michigan. The valve from ISI Fluid Power Inc. is modified by removing the housing gaskets and hermetically sealing the housing for use with refrigerants. Thecontrollable valve 140 is used for controlling fluid flow through theinput conduit 120 which typically carries a higher pressure refrigerant than theconduit 130. Acheck valve 142 is disposed within theinput conduit 130. Thecheck valve 142 includes aball 144, aseat 146, and acage 148. - In operation, timing for the opening and closing of the
controllable valve 140 is provided via the pressure sensor 138 (Figure 1). Timed power output from thepressure sensor 138 to the solenoid of thecontrollable valve 140 is determined by the pressure of the refrigerant in theconduit 120. When thevalve 140 is closed, the low pressure refrigerant in theconduit 130 forces thecheck valve 142 open and the low pressure refrigerant flows from theconduit 130 to theoutput conduit 132. This condition is referred to herein as STATE 1. When thevalve 140 opens thereby allowing refrigerant to flow therethrough, the high pressure refrigerant from theconduit 120 causes thecheck valve 142 to close and remain closed while the high pressure refrigerant is flowing from theconduit 120 to theoutput conduit 132. This condition is referred to herein asSTATE 2. - More particularly, in operation and using, for example, the refrigerant R-12 (dichlorodifluoromethane), refrigerant at about 20 pounds per square inch absolute (psia) is disposed in the
conduit 130 and refrigerant at about 40 psia is disposed in theconduit 120. The inlet pressure to thecompressor unit 102 when thecontrol unit 118 is in STATE 1 is approximately 20 psia. When thecontrol unit 118 is inSTATE 2, the compressor unit inlet pressure is approximately 40 psia. - The
pressure switch 138 is used to control the particular state or configuration of thecontrol unit 118. For example, if it is preferred to maintain the refrigerant in thefirst evaporator 108 at approximately +34°F, a temperature range of approximately +26°F to +36°F is a suitable range for the temperature of the refrigerant in thefirst evaporator 108. By sensing the pressure of the refrigerant in theconduit 120 close to theflow control unit 118, as illustrated by the location of thepressure sensor 118 in Figure 1, there is a one-to-one correspondence between the sensed pressure and the temperature of refrigerant in thefirst evaporator 108. When the pressure sensed by thepressure sensor 138 indicates that the temperature of refrigerant in the first evaporator is above +36°F, the pressure sensor output signal activates thecontrol unit 118, such as by activating thecontrollable valve 140, so that flow communication is established between theconduit 120 and theconduit 132, i.e.,STATE 2. - Although flow communication is established between the
conduits first evaporator 108 only when thethermostat 126 has detected a need for cooling in the freezer compartment thereby activating thecompressor unit 102. For example, when it is preferred to maintain the freezer compartment air temperature at approximately 0°F, a temperature range of -2°F to +2°F is a typical range for the air temperature of the freezer compartment. When the air temperature of the freezer compartment is above +2°F, thethermostat 126 provides that power is supplied to thecompressor unit 102. Subsequent to activation of thecompressor unit 102, once the air temperature of the freezer compartment is below -2°F, thethermostat 126 cuts-off power to thecompressor unit 102. When thecompressor unit 102 is not activated, regardless of the configuration of thecontrol unit 118, substantially no refrigeration effect is provided to the fresh food compartment and the freezer compartment. - When the temperature of refrigerant in the
conduit 120 is above +36°F and the temperature of the freezer compartment is above +2°F, thecontrol unit 118 is disposed inSTATE 2 and thecompressor unit 102 is activated. Once the temperature of refrigerant within the freshfood compartment evaporator 108 is brought to below +26°F, then thepressure sensor 138 causes thecontrol unit 118 to transition into STATE 1. Refrigerant will then be pulled through thefreezer evaporator 124 until the temperature of the freezer compartment is below -2°F. Even when thecontrol unit 118 is in STATE 1, thefresh food evaporator 108 has refrigerant pulled therethrough albeit at a rate slower than the rate when thecontrol unit 118 is inSTATE 2. In order for thefreezer evaporator 124 to have refrigerant pulled therethrough, the temperature of the refrigerant in theconduit 120 must be below +36°F and the temperature of the freezer compartment must be above +2°F. - The
system 100 illustrated and described above was implemented in a General Electric Company Household Refrigerator Model No. TBX25Z with a General Electric Company No. 800 Rotary-type compressor. For compressor unit cycling, the on-period was found to be 22.7 minutes and the off-period was found to be 33.5 minutes (40.4% on-time). Respective evaporator fans (not shown) were provided to blow air across the coils of each evaporator. Each fan was coupled through thethermostat 126 to the power supply, and when thethermostat 126 activated thecompressor unit 102, both fans also were activated and blew air across itsrespective evaporator - Figures 4A-B, respectively, illustrate temperature-enthalpy diagrams. The diagram for Figure 4A is for a refrigeration circuit similar to the
circuit 100 illustrated in Figure 1 but not having thecapillary tube 122 and theconduit 130 disposed in a heat transfer configuration. The diagram in Figure 4B is for therefrigeration circuit 100 illustrated in Figure 1 which, as shown, includes one embodiment of the present heat transfer configuration, i.e., thecapillary tube 122 and theconduit 130 are disposed in a heat transfer configuration. - More particularly, and referring to Figure 4A, the x-axis corresponds to enthalpy (h) and the y-axis corresponds to temperature (T). Again, the circuit under analysis in Figure 4A corresponds to the circuit shown if Figure 1 with the exception that the
capillary tube 122 and theconduit 130, i.e., the freezer evaporator suction line, are not disposed in a heat transfer relationship. On the y-axis, the temperature of air in the fresh food evaporator TFFair and the temperature of air in the freezer evaporator TTZair are indicated. Point 1 on the diagram illustrates the state of refrigerant at the exit of thecondenser 104.Point 2 illustrates the state of refrigerant still within thecapillary tube 106 but at the end of thermal contact with theconduits Point 3 illustrates the state of refrigerant between the outlet of thecapillary tube 106 and the inlet of thefirst evaporator 106. Point 4 illustrates the state of refrigerant at the outlet of thefirst evaporator 106.Point 5 illustrates the state of the refrigerant at the outlet of the phaseseparator vapor portion 114.Point 6 illustrates the state of the refrigerant at the outlet of the phaseseparator liquid portion 116.Point 7 illustrates the state of the refrigerant at the outlet of the capillary tube 122 (again, thecapillary tube 122, in this exemplification, is not in a heat transfer relationship with the conduit 130).Point 8 illustrates the state of the refrigerant at the outlet of theaccumulator 134.Point 9 illustrates the state of the refrigerant within theconduit 130 at the end of thermal contact with thecapillary tube 106.Point 10 illustrates the state of the refrigerant from theconduit 130 at the inlet to the compression chamber of thecompressor unit 102.Point 11 illustrates the state of the refrigerant from theconduit 130 at the outlet of the compression chamber of thecompressor unit 102.Point 12 illustrates the state of the refrigerant from theconduit 130 at the outlet of the compressor motor chamber of thecompressor unit 102.Point 13 illustrates the state of refrigerant in theconduit 120 at the end of thermal contact with thecapillary tube 106.Point 14 illustrates the state of the refrigerant from theconduit 120 at the inlet of the compression chamber of thecompressor unit 102.Point 15 illustrates the state of the refrigerant from theconduit 120 at the outlet of the compression chamber of thecompressor unit 102.Point 16 illustrates the state of the refrigerant from theconduit 120 at the outlet of the compressor motor chamber of thecompressor unit 102. - The temperature-enthalpy diagram in Figure 4A is provided to facilitate an understanding of the thermodynamic advantages provided by the present invention. Particularly, a comparison of the diagrams in Figures 4A and 4B illustrates the specific cooling capacity increase, or regain, in the freezer evaporator provided by the present invention.
- More specifically, the circuit under analysis in Figure 4B corresponds to the circuit shown if Figure 1 which, as illustrated, includes one embodiment of the present invention, i.e., the heat transfer configuration of the
capillary tube 122 and theconduit 130. The points and corresponding numerals indicated in Figure 4A are included in Figure 4B to facilitate a comparison of the thermodynamic characteristics. On the y-axis, the temperature of air in the fresh food evaporator TFFair and the temperature of air in the freezer evaporator TFZair are indicated. Point 1 on the diagram illustrates the state of refrigerant at the exit of thecondenser 104.Point 2 illustrates the state of refrigerant within thecapillary tube 106 at the end of thermal contact with theconduits Point 3 illustrates the state of refrigerant between the outlet of thecapillary tube 106 and the inlet of thefirst evaporator 106. Point 4 illustrates the state of refrigerant at the outlet of thefirst evaporator 106.Point 5 illustrates the state of the refrigerant at the outlet of the phaseseparator vapor portion 114.Point 6 illustrates the state of the refrigerant at the outlet of the phaseseparator liquid portion 116. -
Point 7′ illustrates the state of the refrigerant at the outlet of the capillary tube 122 (note that the capillary tube, in this exemplification, is in a heat transfer relationship with the conduit 130).Point 8 illustrates the state of the refrigerant at the outlet of theaccumulator 134.Point 9′ illustrates the state of the refrigerant within theconduit 130 at the end of thermal contact with thecapillary tube 106.Point 10′ illustrates the state of the refrigerant from theconduit 130 at the inlet to the compression chamber of thecompressor unit 102.Point 11′ illustrates the state of the refrigerant from theconduit 130 at the outlet of the compression chamber of thecompressor unit 102.Point 12′ illustrates the state of the refrigerant from theconduit 130 at the outlet of the compressor motor chamber of thecompressor unit 102.Point 13 illustrates the state of refrigerant in theconduit 120 at the end of thermal contact with thecapillary tube 106.Point 14 illustrates the state of the refrigerant from theconduit 120 at the inlet of the compression chamber of thecompressor unit 102.Point 15 illustrates the state of the refrigerant from theconduit 120 at the outlet of the compression chamber of thecompressor unit 102.Point 16 illustrates the state of the refrigerant from theconduit 120 at the outlet of the compressor motor chamber of thecompressor unit 102. - The present heat transfer configuration provides for a specific cooling capacity increase in the
freezer evaporator 124. The increase in specific cooling capacity results in a decrease in the amount of mechanical energy required to cool the freezer evaporator. The cooling capacity increase which actually results in practice, of course, depends upon the actual mass flow rate through the freezer evaporator. More particularly, and referring to Figure 4A, the mass flow rates m are designated as follows: - mT =
- total mass flow rate;
- mL =
- mass flow rate through the
freezer evaporator 124; and - mH =
- mass flow rate through the
fresh food evaporator 108. - When the heat transfer of the present invention is utilized, as illustrated in Figure 4B, then Equation 1 becomes:
freezer evaporator 124 by addition of mL(h₇ - h7′). The actual cooling capacity increase, of course, depends upon the mass flow rate of refrigerant flowing through thefreezer evaporator 124. The increase in cooling capacity also provides that less mechanical energy is required to cool the freezer compartment. Specifically, the compressor unit operating time required to satisfy the cooling demand of the freezer compartment is reduced because the cooling supplied by thefreezer evaporator 124 is increased during operation. - Figure 5 is a block diagram illustration of a
household refrigerator 200 including aninsulated wall 202 forming afresh food compartment 204 and afreezer compartment 206. Figure 4 is provided for illustrative purposes only, and particularly to show one apparatus which has substantially separate compartments which require refrigeration at different temperatures. In the household refrigerator, thefresh food compartment 204 and thefreezer compartment 206 typically are maintained at about +33°F to +47°F and-10°F to +15°F, respectively. - A
first evaporator 208 is shown disposed in thefresh food compartment 204 and asecond evaporator 210 is shown disposed in thefreezer compartment 206. The present invention is not limited to the physical location of the evaporators, and the location of the evaporators shown in Figure 5 is only for illustrative purposes and to facilitate ease of understanding. It is contemplated that theevaporators - The first and
second evaporators compressor unit 212 and acondenser 214 shown located in a compressor/condenser compartment 216. Atemperature sensor 218, such as thethermostat 126 shown in Figure 1, is disposed in thefreezer compartment 206. Thesensor 218, of course, preferably is user adjustable so that a system user selects a temperature, or temperature range, at which the compressor is to be activated and/or inactivated. Thefirst evaporator 208 typically is operated at between approximately +15°F to approximately +32°F and thesecond evaporator 210 typically is operated at approximately -30°F to approximately 0°F in order to maintain thefresh food compartment 204 at between approximately +33°F to +47°F and thefreezer compartment 206 between approximately -10°F to +15°F, respectively. - Figure 6 illustrates a second embodiment of the present invention wherein more than two evaporators are utilized. More than two evaporators provide even further efficiencies in some contexts. For example, in some contexts, it is desired to provide a household refrigerator with a third evaporator to quickly chill or freeze selected items in a separate compartment.
- Particularly,
embodiment 300 includes acompressor unit 302 coupled to acondenser 304. The outlet of thecondenser 304 is coupled to afirst expansion valve 306 which has its outlet coupled to afirst evaporator 308. The outlet of thefirst evaporator 308 is coupled to the inlet of afirst phase separator 310. Thefirst phase separator 310 includes ascreen 312, avapor portion 314 and aliquid portion 316. The phaseseparator vapor portion 314 is coupled, as a first input, to a refrigerantflow control unit 318. Particularly, aconduit 320 extends from the first phaseseparator vapor portion 314 to thecontrol unit 318 and theconduit 320 is arranged within thephase separator 310 so that liquid refrigerant entering the phaseseparator vapor portion 314 passes through thevapor portion 314 and cannot enter the open end of theconduit 320. The outlet of the first phaseseparator liquid portion 316 is coupled to a firstcapillary tube 322. Asecond evaporator 324 is coupled to the outlet of the firstcapillary tube 322, and the outlet of thesecond evaporator 324 is coupled to the inlet of asecond phase separator 326. Thesecond phase separator 326 includes ascreen 328, avapor portion 330 and aliquid portion 332. The phaseseparator vapor portion 330 is coupled, as a second input,, to the refrigerantlow control unit 318. Particularly, aconduit 334 extends from the second phaseseparator vapor portion 330 to thecontrol unit 318 and theconduit 334 is arranged within thephase separator 326 so that liquid refrigerant entering the phaseseparator vapor portion 330 passes through thevapor portion 330 and cannot enter the open end of theconduit 334. The outlet of the second phaseseparaator liquid portion 332 is coupled to a secondcapillary tube 336. Athird evaporator 338 is coupled to the outlet of the secondcapillary tube 336, and the outlet of thethird evaporator 338 is coupled, as a third input, to the refrigerantlow control unit 318. - First and
second sensors second evaporators sensors evaporators second sensors timer 344. Thetimer 344 is a a variable timer. Rather than thetimer 344, a sensor switch can be utilized. Also, a fixed timer can be used to drive thecontrol unit 318. With the fixed timer, of course, thesensors sensors - The
control unit 318 shown in Figure 5 comprises first and secondcontrollable valves 346 and 348. Particularly, thevalves 346 and 348 preferably are on-off solenoid valves which are well-known in the art. Thecontrol unit 318 further comprises acheck valve 350. The first and secondcontrollable valves 346 and 348 receive, as inputs, refrigerant flowing through theconduits conduit 352, which is coupled to the third evaporator, provides input refrigerant to thecheck valve 350. - In operation, each valve of the
control unit 318 alternately opens to allow refrigerant to flow through the respective evaporators to thecompressor unit 302. For example, when the first valve 346 is open and thevalve 348 is closed, refrigerant flows through thefirst evaporator 308 to thephase separator 310 and to thecompressor unit 302 via theconduit 320. Refrigerant does not flow through the second orthird evaporators - Similarly, when the first valve 346 is closed and the
second valve 348 is open, refrigerant flows from theliquid portion 314 of thephase separator 310, through theexpansion device 322, through thesecond evaporator 324, to thephase separator 326, and to thecompressor unit 302 via theconduit 334. Vapor refrigerant does not flow from thefirst phase separator 310 or from thethird evaporator 338 to thecompressor unit 302 at this time. Refrigerant flows through thefirst evaporator 308 from thecondenser 304 at this time. - When both the
valves 346 and 348 are closed, thethird valve 350 automatically opens and liquid refrigerant flows from the second phaseseparator liquid portion 332, through theexpansion device 336, though thethird evaporator 338, and to thecompressor unit 302. Refrigerant also flows through thefirst evaporator 308 and thesecond evaporator 324 at this time. - Relative to each other, a higher pressure refrigerant flows through the
conduit 320, a medium pressure refrigerant flows through theconduit 334, and a lower pressure refrigerant flows through theconduit 350. Thetimer 344 controls the duty cycle of thecontrol unit 318. The specific duty cycle selected depends, of course, upon the desired operating parameters of each evaporator. It will be understood that thetimer 344 controls thevalves 346 and 348 so that they open alternately or are both closed, but they are not concurrently open. A thermostat (not shown), of course, normally is provided to control activation of thecompressor unit 302. - The
first evaporator 308 operates at a temperature higher than the operating temperatures of the second andthird evaporators third evaporator 338 operates at a temperature lower than the operating temperatures of the first andsecond evaporators second evaporator 310 operates at a temperature intermediate the operating temperatures of the first andthird evaporators - In accordance with the present invention, the
conduit 352, i.e., the suction line of thethird evaporator 338, is disposed in a counterflow heat transfer arrangement with the secondcapillary tube 336 and with the firstcapillary tube 322. This embodiment of the present invention provides for regain of specific cooling cappacity in thethird evaporator 338 in a manner similar to the regain in specific cooling capacity as described with reference to the embodiment of the present invention illustrated in Figure 1. In the Fig. 6 embodiment, however, additional specific cooling capacity is potentially regained by disposing theconduit 352 in counterflow heat transfer arrangements with both the firstcapillary tube 322 and the secondcapillary tube 336. - Figure 7 illustrates a third embodiment of a
refrigeration system 400 including a third embodiment of the present heat transfer configuration. Particularly, in Figure 7, therefrigeration system 400 comprises afirst compressor unit 402 and asecond compressor unit 404, the outlet of thefirst compressor unit 402 being connected to the inlet of thesecond compressor unit 404. A firstcapillary tube 406 is coupled to the outlet of thesecond compressor unit 404, and the outlet of the firstcapillary tube 406 is coupled to the inlet of afirst expansion device 408. The outlet of thefirst expansion device 408 is coupled to the inlet of thefirst evaporator 410, and the outlet of thefirst evaporator 410 is coupled to the inlet of aphase separator 412. Thephase separator 412 includes ascreen 414 disposed adjacent the phase separator inlet, avapor portion 416 and aliquid portion 418. The outlet of thevapor portion 416 is connected to theconduit 420 disposed between and coupling thefirst compressor unit 402 and thesecond compressor unit 404. Theliquid portion 418 is connected to a secondcapillary tube 422. The outlet of the secondcapillary tube 422 is connected to the inlet of asecond evaporator 424. The outlet of thesecond evaporator 424 is connected to anaccumulator 426, and the outlet of theaccumulator 426 is connected to the inlet of thefirst compressor unit 402 via theconduit 428. Theaccumulator 426 operates in a manner similar to operation of theaccumulator 134 illustrated in Figure 1. Particularly, theaccumulator 426 is identical to theaccumulator 134 illustrated in more detail in Figure 2. Liquid refrigerant discharged from thesecond evaporator 424 is stored within theaccumulator 426 until the liquid refrigerant is evaporated such as by superheated refrigerant being discharged from thesecond evaporator 124. - This embodiment of the present invention provides for regain of specific cooling capacity in the
second evaporator 424 in a manner similar to the regain in specific cooling capacity as described with reference to the embodiment of the present invention illustrated in Figure 1. Particularly, by disposing theconduit 428 in a counteflow heat transfer arrangement with thecapillary tube 422, specific cooling capacity regain in thesecond evaporator 424 is provided. Theembodiment 400 in Figure 7 is provided primarily to illustrate one embodiment of the present invention in a refrigeration circuit including a plurality of compressors or a compressor having a plurality of stages. - It is contemplated that in some refrigeration systems, all of the energy efficiencies and reduced costs provided by the present invention may not be strictly necessary. As a result, others may attempt to modify the invention as described herein, such modifications resulting in varying efficiency and/or increased costs relative to the described embodiments. For example, a plurality of compressors or a compressor having a plurality of stages or any combination thereof, along with the refrigerant flow control means, may be utilized. Such modifications are possible, contemplated, and within the scope of the appended claims. Further, while the present invention is described herein sometimes with reference to a household refrigerator, it is not limited to practice with and/or in a household refrigerator.
- While preferred embodiments have been illustrated and described herein, it will be obvious that numerous modifications, changes, variations, substitutions and equivalents, in whole or in part, will now occur to those skilled in the art without departing from the spirit and scope contemplated by the invention.
Claims (14)
- A refrigeration circuit, comprising,
compressor means;
a plurality of evaporator means coupled to said compressor means, one of said evaporator means being arranged to operate at a temperature lower than the operating temperature of said other evaporator means; and
a first conduit means coupled to the outlet of said one evaporator means, said first conduit means being at least partially disposed in a heat transfer arrangement with at least a portion of a second conduit means coupled to the inlet of said one evaporator means. - A heat transfer arrangement for a refrigerator, the refrigerator including compressor means, condenser means connected to receive refrigerant discharged from said compressor means, a fresh food compartment, first evaporator means for refrigerating said fresh food compartment and connected to receive at least part of the refrigerant discharged from said condenser means, a freezer compartment, second evaporator means for refrigerating said freezer compartment and connected to receive at least part of the refrigerant discharged from said condenser means, refrigerant flow control means connected to receive at least part of the refrigerant discharged from said first evaporator means and at least part of the refrigerant discharged from said second evaporator means and operable to alternately connect said first and said second evaporator means in fluid flow relationship with said compressor means, said heat transfer arrangement comprising:
a first conduit means coupled to the outlet of said second evaporator means, said first conduit means being at least partially disposed in a heat transfer arrangement with at least a portion of a second conduit means coupled to the inlet of said second evaporator means. - A heat transfer arrangement in accordance with Claim 1 or 2 wherein at least a portion of said first conduit means is disposed in a counterflow heat transfer arrangement with at least a portion of said second conduit means.
- A heat transfer arrangement in accordance with Claim 1 or 2 wherein said first conduit means comprises an accumulator means, said accumulator means disposed in the refrigerant flow path between said second evaporator means and said heat transfer arrangement.
- A heat transfer arrangement in accordance with Claim 1 or 2 wherein said second conduit means comprises a capillary tube, at least a portion of said first conduit means being disposed in a heat transfer arrangement with at least a portion of said capillary tube.
- A heat transfer arrangement in accordance with Claim 5 wherein said portion of said first conduit means is disposed in a counterflow heat transfer arrangement with said portion of said capillary tube.
- A refrigeration system, comprising,
compressor means;
a first, second and third evaporator means coupled to said compressor means, said third evaporator means being arranged to operate at a temperature lower than the operating temperature of said first and second evaporator means; and
a first conduit means coupled to the outlet of said third evaporator means, said first conduit means being at least partially disposed in a first heat transfer arrangement with at least a portion of a second conduit means coupled to the inlet of said third evaporator means, said second conduit means being disposed between said second and third evaporator means. - A refrigeration system in accordance with Claim 7 wherein said first conduit means is further disposed in a second heat transfer arrangement with at least a portion of a third conduit means coupled to the inlet of said second evaporator means, said third conduit means being disposed between said first and second evaporator means.
- A refrigeration system in accordance with Claim 8 wherein at least a portion of said first conduit means is disposed in a first counterflow heat transfer arrangement with said portion of said second conduit means, and said first conduit means is disposed in a second counteflow heat transfer arrangement with said portion of said third conduit means.
- A refrigeration system in accordance with Claim 8 wherein said second conduit means comprises a first capillary tube, at least a portion of said first conduit means being disposed in said first heat transfer arrangement with at least a portion of said first capillary tube.
- A refrigeration system in accordance with Claim 10 wherein said portion of said first conduit means is disposed in a counterflow heat transfer arrangement with said portion of said first capillary tube.
- a refrigeration system in accordance with Claim 8 wherein said third conduit means comprises a second capillary tube, at least a portion of said first conduit means being disposed in said second heat transfer arrangement with at least a portion of said second capillary tube.
- A refrigeration system in accordance with Claim 12 wherein said portion of said first conduit means is disposed in a counteflow heat transfer arrangement with said portion of said second capillary tube.
- A refrigeration system in accordance with Claim 7 wherein said first conduit means includes an accumulator means, said accumulator means disposed in the refrigerant flow path between said third evaporator means and said first heat transfer arrangement.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US61205190A | 1990-11-09 | 1990-11-09 | |
US612051 | 1990-11-09 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0485147A1 true EP0485147A1 (en) | 1992-05-13 |
EP0485147B1 EP0485147B1 (en) | 1996-06-19 |
Family
ID=24451511
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19910310187 Expired - Lifetime EP0485147B1 (en) | 1990-11-09 | 1991-11-05 | Refrigeration system |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0485147B1 (en) |
JP (1) | JP3321192B2 (en) |
DE (1) | DE69120376T2 (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0624763A1 (en) * | 1993-05-10 | 1994-11-17 | General Electric Company | Free-draining evaporator for refrigeration system |
EP1779047A2 (en) * | 2004-07-14 | 2007-05-02 | Carrier Corporation | Refrigeration system |
CN103512257A (en) * | 2013-09-27 | 2014-01-15 | 西安交通大学 | Non-azeotropic hydrocarbon mixture automatic overlapping refrigerating cycle system for double-temperature refrigerator |
WO2014048485A1 (en) * | 2012-09-28 | 2014-04-03 | Electrolux Home Products Corporation N. V. | Refrigerator |
CN104776595A (en) * | 2015-04-28 | 2015-07-15 | 唐玉敏 | Solar multi-collection heat utilization system |
CN112601921A (en) * | 2018-08-31 | 2021-04-02 | 三星电子株式会社 | Refrigerator with a door |
US11674732B2 (en) | 2018-08-31 | 2023-06-13 | Samsung Electronics Co., Ltd. | Refrigerator |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7824725B2 (en) | 2007-03-30 | 2010-11-02 | The Coca-Cola Company | Methods for extending the shelf life of partially solidified flowable compositions |
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US2081883A (en) * | 1934-11-26 | 1937-05-25 | Kelvinator Corp | Refrigerating apparatus |
GB639691A (en) * | 1947-01-04 | 1950-07-05 | British Thomson Houston Co Ltd | Improvements in and relating to refrigerating systems |
US4130997A (en) * | 1975-12-10 | 1978-12-26 | Hitachi, Ltd. | Refrigerator |
US4291548A (en) * | 1980-07-07 | 1981-09-29 | General Motors Corporation | Liquid accumulator |
US4918942A (en) * | 1989-10-11 | 1990-04-24 | General Electric Company | Refrigeration system with dual evaporators and suction line heating |
-
1991
- 1991-11-05 EP EP19910310187 patent/EP0485147B1/en not_active Expired - Lifetime
- 1991-11-05 DE DE1991620376 patent/DE69120376T2/en not_active Expired - Fee Related
- 1991-11-07 JP JP31861091A patent/JP3321192B2/en not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
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US2081883A (en) * | 1934-11-26 | 1937-05-25 | Kelvinator Corp | Refrigerating apparatus |
GB639691A (en) * | 1947-01-04 | 1950-07-05 | British Thomson Houston Co Ltd | Improvements in and relating to refrigerating systems |
US4130997A (en) * | 1975-12-10 | 1978-12-26 | Hitachi, Ltd. | Refrigerator |
US4291548A (en) * | 1980-07-07 | 1981-09-29 | General Motors Corporation | Liquid accumulator |
US4918942A (en) * | 1989-10-11 | 1990-04-24 | General Electric Company | Refrigeration system with dual evaporators and suction line heating |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0624763A1 (en) * | 1993-05-10 | 1994-11-17 | General Electric Company | Free-draining evaporator for refrigeration system |
EP1779047A2 (en) * | 2004-07-14 | 2007-05-02 | Carrier Corporation | Refrigeration system |
EP1779047A4 (en) * | 2004-07-14 | 2010-05-05 | Carrier Corp | Refrigeration system |
WO2014048485A1 (en) * | 2012-09-28 | 2014-04-03 | Electrolux Home Products Corporation N. V. | Refrigerator |
CN104685305A (en) * | 2012-09-28 | 2015-06-03 | 伊莱克斯家用产品公司 | Refrigerator |
CN103512257A (en) * | 2013-09-27 | 2014-01-15 | 西安交通大学 | Non-azeotropic hydrocarbon mixture automatic overlapping refrigerating cycle system for double-temperature refrigerator |
CN103512257B (en) * | 2013-09-27 | 2016-01-20 | 西安交通大学 | For the non-azeotrope hydrocarbon mixture self-cascade refrigeration system system of two temperature refrigerator |
CN104776595A (en) * | 2015-04-28 | 2015-07-15 | 唐玉敏 | Solar multi-collection heat utilization system |
CN112601921A (en) * | 2018-08-31 | 2021-04-02 | 三星电子株式会社 | Refrigerator with a door |
US11674732B2 (en) | 2018-08-31 | 2023-06-13 | Samsung Electronics Co., Ltd. | Refrigerator |
Also Published As
Publication number | Publication date |
---|---|
DE69120376T2 (en) | 1997-02-06 |
DE69120376D1 (en) | 1996-07-25 |
JPH04288454A (en) | 1992-10-13 |
JP3321192B2 (en) | 2002-09-03 |
EP0485147B1 (en) | 1996-06-19 |
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