Abstract: A refrigeration machine for a domestic refrigerator includes a compressor, a condenser and an evaporator, which are connected to form a refrigerant circuit, wherein a stop valve is arranged in a refrigerant path from the condenser to the evaporator.

Abstract: Heat pumps with improved defrost cycles, methods of defrosting heat exchangers, and methods of improving the effectiveness of defrost cycles of heat pumps, for example, having a microchannel outdoor heat exchanger. A defrost valve in a refrigerant conduit opens during a defrost cycle to deliver hot refrigerant gas to a portion of the heat exchanger that otherwise defrosts more slowly or less completely than other portions of the heat exchanger. Particular embodiments pass hot refrigerant gas through a header of the heat exchanger, such as a bottom header. In a number of embodiments, the defrost valve is open only during a portion of the defrost cycle. Further, in some embodiments, the fan that is used to blow air through the heat exchanger is operated in a reversed direction during at least part of the defrost cycle to counteract natural convection through the heat exchanger.

Abstract: A heat pump system includes a controller and a closed system that includes a condensing heat exchanger coil, an evaporating heat exchanger coil, a refrigerant and a compressor. The compressor is configured to compress the refrigerant, thereby causing the refrigerant to have a greater pressure in the condensing heat exchanger coil than in the evaporating heat exchanger coil. The controller is configured to perform a passive defrost of the evaporating heat exchanger coil. The passive defrost includes disabling the compressor and providing a bypass path between the condensing and evaporating heat exchanger coils that bypasses the compressor. The bypass path allows the refrigerant to flow from the condensing heat exchanger coil to the evaporating heat exchanger coil while the compressor is disabled.

Abstract: A first bypass pipe has one end connected to a main pipe extending from a compressor to an indoor heat exchanger, and its other end branched off into parts that are each connected to the main pipe on an inlet side of an outdoor heat exchanger, and a second bypass pipe has one end connected to an injection port communicating with the compression chamber of the compressor in which compression is taking place and its other end branched off into parts that are each connected to the main pipe on an outlet side of the outdoor heat exchangers. During a defrosting operation that removes frost on the outdoor heat exchangers, a part of the refrigerant discharged from the compressor is supplied from the first bypass pipe to the outdoor heat exchanger to be defrosted, and is then passed through the second bypass pipe and injected from the injection port of the compressor.

Abstract: An air conditioning system is provided. The air conditioning system allows coolant to selectively flow through a series of bypass pipes and valves connecting an outlet of a compressor and an outlet of an expansion member. The series of bypass pipes and valves allow a defrosting function to be performed without performing a reverse cycle.

Abstract: In a heat pump cycle, refrigerant tubes of an outdoor heat exchanger serving as an evaporator for evaporating refrigerant, and cooling fluid tubes of a radiator for dissipating heat from a coolant of an electric motor for traveling serving as an external heat source are bonded to the same outer fins. The heat contained in the coolant flowing through the cooling fluid tubes can be transferred to the refrigerant tubes of the outdoor heat exchanger via the outer fins. Thus, in the defrosting operation which involves defrosting the outdoor heat exchanger by flowing the coolant through the radiator, the loss in transfer of the heat contained in the coolant to the outdoor heat exchanger can be suppressed, and the heat supplied from the electric motor for traveling can be effectively used for defrosting the outdoor heat exchanger.

Abstract: A method and system for removing oil accumulation from refrigerant lines of a vehicle HVAC system having multiple refrigerant loops each having an evaporator is disclosed. The method for operating the system may comprise the steps of: monitoring a flow rate through at least one of the refrigerant loops; determining if the flow rate through any of the at least one refrigerant loops being monitored is below a predetermined flow rate for greater than a predetermined time limit; monitoring for an indication of imminent vehicle operation; and if the indication of imminent vehicle operation is detected and the flow rate through any of the at least one refrigerant loops being monitored is below the predetermined flow rate for greater than the predetermined time limit, opening a valve to allow for maximum flow through the at least one refrigerant loop.

Abstract: Embodiments of systems, apparatus, and/or methods can provide a damper assembly for transport refrigeration systems. One embodiment can include a damper assembly including a damper door configured to operate in a first position (e.g., closed), a second position (e.g., open), and at least one intermediate position. In one embodiment, a plurality of intermediate positions can be used to controllably vary a capacity of the transport refrigeration unit, or at least one component thereof. Embodiments of systems, apparatus, and/or methods can provide a damper assembly that can be accessed though an ambient portion of transport refrigeration systems or components.

Abstract: An ejector-type refrigerant cycle device includes: a first evaporator 15 that evaporates refrigerant flowing out of an ejector 14; a branch passage 17 that branches a flow of refrigerant between a radiator 13 and the ejector 14 and guides this flow of refrigerant to a vapor-phase refrigerant suction port 14c of the ejector 14; a throttling mechanism 18 disposed in the branch passage 17; and a second evaporator 19 disposed downstream of the throttling mechanism 18 with respect to the flow of refrigerant. The throttling mechanism 18 is constructed to be provided with a fully opening function, and to fully open the branch passage 17 when the second evaporator 19 is defrosted. Therefore, in an ejector-type refrigerant cycle device including multiple evaporators, the function of defrosting the evaporators can be carried out with a simple construction.

Abstract: Systems and methods for refrigerating crops and other goods and for defrosting a refrigeration system. A refrigerant is circulated between a condenser and a refrigerator to cool air in the refrigerator. Heat is removed from the refrigerant at the condenser. Periodically the cycle of refrigerant and air can be reversed to melt frost in the refrigerator. Frost can be detected by a sensing mechanism and the refrigerant and air cycles can be reversed in response to detecting the frost. The frost can be removed quickly without removing the goods from the refrigerant.

Abstract: An air conditioner that can perform defrosting efficiently while heating or the like is continued even if the air conditioner is configured by one outdoor unit is obtained.

Abstract: The present invention proposes a water circulation system associated with a refrigerant cycle that can selectively heat-exchange water for cooling and heating and hot water supplying with at least one of a first refrigerant and a second refrigerant. Therefore, the present invention can improve the operation efficiency of the water circulation system associated with the refrigerant cycle.

Abstract: A refrigerant system has a refrigerant circuit comprising a compressor for compressing a refrigerant and delivering it downstream to a condenser. A bypass line is provided around the condenser for selectively allowing at least a portion of refrigerant to bypass the condenser. Valves are provided on a line leading to the condenser and on the bypass line to individually control the flow of refrigerant. An expansion device is located downstream of the condenser, and an evaporator is located downstream of the expansion device. A reheat cycle is incorporated into the system. The reheat cycle includes a valve for selectively delivering at least a portion of refrigerant through a reheat heat exchanger, which is positioned in the path of air downstream of the evaporator. A control is provided for the system to achieve a desired level of dehumidification and temperature control to air being delivered into the environment to be conditioned.

Abstract: A method of operating a reversible heat pump system includes steps of sensing an outdoor air temperature with a first sensor and sensing at least one condition of an outdoor heat exchanger coil with a second sensor. Input from the first and second sensors is then electronically analyzed to predict when frosting may occur on an outdoor heat exchanger coil. A proportioning reversing valve is modulated in response to this analysis in order to direct a controlled proportional backpressure flow of pressurized refrigerant from a pressure side of a compressor into the outdoor heat exchanger coil while pressurized refrigerant is continued to be supplied to an indoor heat exchanger coil. As a result, the pressure and temperature of refrigerant within the outdoor heat exchanger coil is raised to at least an extent necessary to prevent frosting on the outdoor heat exchanger coil. The steps are preferably performed continuously in a feedback control loop during operation of the reversible heat pump system as a heat pump.

Abstract: A hot water storage tank (3) and a circulating path (12) coupled to the hot water storage tank (3) are provided. An operation is possible wherein low-temperature water, let out from a lower part of the hot water storage tank (3) and entering the circulating path (12), is heated and boiled up by a heat pump heating source for forwarding to an upper part of the hot water storage tank (3). A refrigerant circulating circuit of the heat pump heating source is provided with a defrost circuit (38) for supplying hot gas from a compressor (25) to an air heat exchanger (28). It is possible to perform a defrost operation for providing a supply of hot gas to the air heat exchanger (28), with a water circulation pump (13) of the circulating path (12) held in abeyance. The water circulation pump (13) is made active if the defrost operation has been continued for not less than a predetermined time period since the start thereof.

Abstract: A method of and apparatus for defrosting an evaporator in a cooling system are provided. The cooling system includes a compressor, a condenser, an evaporator and a refrigerant that is circulated in sequence from the compressor to the condenser, to the evaporator and back to the compressor during routine operation of the cooling system. The method and apparatus comprise shutting off the flow of the refrigerant from the compressor to the evaporator through the condenser while continuing to operate the compressor so as to apply suction to the refrigerant in the evaporator and thereafter directing compressed refrigerant from the compressor to the evaporator while bypassing the condenser and continuing to shut off the flow of the refrigerant from the compressor to the evaporator through the condenser.

Abstract: A portable instrument for providing an on-site ice cream, comprise of all natural ingredients, in front of a customer is provided. The instrument according to the current application is comprised of; 1) a compressor equipped with a condenser having heat removal capacity of 12,000 BTU/hr, 2) an exit tube, 3) a condenser tube, 4) an expansion valve, 5) an outlet copper tube, 6) a coiled coolant pipe, 7) a stainless steel shallow bowl shape plate welded on the coolant pipes, 8) an inlet copper tube, 9) a separator, 10) a by pass line that connects the exit tube and the outlet copper tube, 11) a solenoid valve, and 12) a foot stepper to control on/off of the solenoid valve. Slurry of a mixture of fruits, milk, cream powder and honey syrup, formed from an electric mixer is dumped on the stainless steel plate, which is maintained at the very low temperature between ?31 C to ?35 C.

Abstract: An ejector-type refrigerant cycle device includes: a first evaporator 15 that evaporates refrigerant flowing out of an ejector 14; a branch passage 17 that branches a flow of refrigerant between a radiator 13 and the ejector 14 and guides this flow of refrigerant to a vapor-phase refrigerant suction port 14c of the ejector 14; a throttling mechanism 18 disposed in the branch passage 17; and a second evaporator 19 disposed downstream of the throttling mechanism 18 with respect to the flow of refrigerant. The throttling mechanism 18 is constructed to be provided with a fully opening function, and to fully open the branch passage 17 when the second evaporator 19 is defrosted. Therefore, in an ejector-type refrigerant cycle device including multiple evaporators, the function of defrosting the evaporators can be carried out with a simple construction.

Abstract: A refrigerant vapor compression system includes an evaporator having a plurality of longitudinally extending, flattened heat exchange tubes disposed in parallel, spaced relationship. Each of the heat exchange tubes has a flattened cross-section and defining a plurality of discrete, longitudinally extending refrigerant flow passages. One or more frost detection sensor(s) is/are installed in operative association with the evaporator for detecting a presence of frost/ice formation on at one of the flattened heat exchange tubes and associated heat transfer fins. A defrost system is provided and operatively associated with the evaporator heat exchanger A controller, operatively coupled to the frost detection sensor(s) and to the defrost system, selectively activates the defrost system to initiate a defrost cycle of the evaporator in response to the signal indicative of the presence of frost formation on the flattened heat exchange tubes and heat transfer fins.

Abstract: The present invention provides an air-conditioning system capable of continuous heating operation over an outdoor temperature range of 20 degree to negative 40 degree Celsius. The present invention utilizes at least two sets of the evaporators capable of cross-reverse refrigerant circulation and cross-air defrosting process, which alternately generates the heat energy required for the defrosting process and the air-conditioning, and said air-conditioning system can apply a combination of the two defrost methods to raise overall heating efficiency.

Abstract: A method of and apparatus for defrosting an evaporator in a cooling system are provided. The cooling system includes a compressor, a condenser, an evaporator and a refrigerant that is circulated in sequence from the compressor to the condenser, to the evaporator and back to the compressor during routine operation of the cooling system. The method and apparatus comprise shutting off the flow of the refrigerant from the compressor to the evaporator through the condenser while continuing to operate the compressor so as to apply suction to the refrigerant in the evaporator and thereafter directing compressed refrigerant from the compressor to the evaporator while bypassing the condenser and continuing to shut off the flow of the refrigerant from the compressor to the evaporator through the condenser.

Abstract: The present invention provides a method and apparatus for using hot gas to defrost sequentially each refrigerated display case (evaporator) in a group of refrigerated display cases (evaporators). A unique cross-feed line connects the distributor and the evaporator suction line for each evaporator in the group of evaporators. Like a typical hot gas defrost system, the sequential hot gas defrost system may be time-initiated and time-terminated or time-initiated and temperature-terminated. Each evaporator in the group of evaporators is defrosted in turn while the remaining evaporators in the group continue to operate in the refrigeration mode. A unitary combination check valve and orifice simplifies the sequential hot gas defrost refrigeration system.

Abstract: Defrosting operation is possible by causing refrigerant discharged from a compressor to flow to an outdoor heat exchanger, and returning the refrigerant passed through the outdoor heat exchanger to the compressor through a water-heat exchanger, while operating a pump. Quick defrosting operation is possible by causing refrigerant discharged from a compressor to flow to an outdoor heat exchanger, and returning the refrigerant passed through the outdoor heat exchanger directly to the compressor, while stopping a pump. The temperature of water that has flowed into a water-heat exchanger is detected. According to the detected temperature, the defrosting operation using hot water and quick defrosting operation are selectively executed.

Abstract: A bottle cooler system (20, 70, 100) includes a compressor (22), a first heat exchanger (24) and a second heat exchanger (28). In a cooling mode of operation, the second heat exchanger is downstream of the first heat exchanger and upstream of the compressor to cool contents of an interior volume. In a defrost mode of operation, refrigerant in the second heat exchanger is used to defrost an ice build-up on the second heat exchanger.

Abstract: A defrost refrigeration system comprises first compressors and second compressors serially positioned with respect to one another such that refrigerant going through a compression stage in the refrigeration cycle passes sequentially through the first compressors and the second compressors. A first line extends from an exit of one of the first compressor and the second compressor of the compression stage, and is in fluid communication with the evaporator stage in a defrost cycle and is adapted to receive a defrost portion of refrigerant compressed in the compression stage. Valves switch evaporators between the refrigeration cycle and the defrost cycle, by stopping/allowing a flow of refrigerant from the condensation stage to the evaporators of the evaporation stage in the refrigeration cycle, and for allowing/stopping a flow of said defrost portion of refrigerant to defrost the evaporators in the defrost cycle.

Abstract: The present invention relates to an evaporator arrangement for an air conditioning system of an aircraft, wherein a bypass conduit is provided which can be connected such that if required at least part of the airflow bypasses an evaporator. Advantageously this makes it possible in the case of malfunction of the evaporator to maintain the functionality of the air conditioning system.

Abstract: An ejector cycle device includes an ejector having a nozzle portion which decompresses refrigerant flowing out of a radiator, a first evaporator for evaporating refrigerant from the ejector, and a second evaporator provided in a branch passage that is branched from a position between the refrigerant radiator and the ejector and is connected to a refrigerant suction port of the ejector. Furthermore, a throttle member is disposed in the branch passage to decompress refrigerant and adjust a flow amount of refrigerant, and the second evaporator is disposed in the branch passage between the throttle member and the refrigerant suction port. In the ejector cycle device having both the first and second evaporators, a defrosting operation of one the first and second evaporators can be performed while the other one of the first and second evaporators is operated to have a cooling function.

Abstract: A refrigeration system including a compressor, a condenser, and an evaporator in heat exchange relationship with a fluid deliverable to a space. The evaporator is connected to the condenser via an inlet line and to the compressor via a suction line. A refrigeration circuit is defined by the compressor, condenser, inlet line, evaporator, and suction line. A refrigeration mode of the refrigeration circuit transfers heat from the fluid to a refrigerant in the evaporator and accumulates frost on the evaporator. The evaporator, a bypass line connected to the suction line and to the inlet line, a portion of the suction line, and a portion of the inlet line define a defrost circuit that circulates refrigerant in a defrost mode to transfer heat from the refrigerant to the frost on the evaporator. The refrigerant flows by gravity from the evaporator to one of the portion of the suction line and the portion of the inlet line in the defrost mode.

Abstract: A refrigerant cycle device includes an ejector having a nozzle portion for decompressing refrigerant and a refrigerant suction port from which refrigerant is drawn by a high-speed refrigerant stream jetted from the nozzle portion, and a refrigerant branch passage branched from an upstream side of the nozzle portion in a refrigerant flow such that refrigerant flows into the refrigerant suction port through the refrigerant branch passage. Furthermore, a first heat exchanger is disposed to evaporate refrigerant flowing out of the ejector, a second heat exchanger is disposed in the refrigerant branch passage to evaporate refrigerant, and a temperature sensor is located to detect a temperature so as to detect a frost in the second heat exchanger. In addition, a controller performs a frost prevention control for reducing the frost in the second heat exchanger, in accordance with the temperature detected by the temperature sensor.

Abstract: In a refrigerant circuit (20), a refrigerator circuit (110) and a freezing circuit (30) are connected in parallel to an outdoor circuit (40). In the freezing circuit (30), a freezer circuit (130) and a booster circuit (140) are connected in series. A booster compressor (141) and a four-way switch valve (142) are provided in the booster circuit (140). During the time when a freezer heat exchanger (131) performs cooling operation for cooling the inside air, refrigerant evaporated in the freezer heat exchanger (131) is compressed in the booster compressor (141), and then, is sucked into a variable capacitance compressor (41). On the other hand, during defrosting of the freezer heat exchanger (131), the refrigerant evaporated in a refrigerator heat exchanger (111) is compressed in the booster compressor (141), and then, is supplied to the freezer heat exchanger (131).

Abstract: An object of the invention is to effectively defrost multiple a vaporizing devices provided in an ejector cycle. In one of the embodiments, electric heating devices are provided for the respective first and second vaporizing devices, to carry out defrosting operations for each vaporizing device. In addition, a defrosting operation is carried out for the second vaporizing device by hot-gas from a compressor.

Abstract: Rotating wheel dessicants employed in dehumidifying moisturized air present within a water-damaged building are themselves dehumidified to liberate collected moisture through the use of ambient air drawn over and about a heat exchanger fired by diesel fuel, with the rotating wheel dessicant being turned by a grip notch belt stretched onto the wheel.

Abstract: Dessicants employed in dehumidifying moisturized air present within a water-damaged building are themselves dehumidified to liberate collected moisture through the use of ambient air drawn over and about a heat exchanger fired by diesel fuel, with portions of the air drawn through the dessicant in both directional air flow paths being used to heat the water-damaged building.

Abstract: Dessicants employed in dehumidifying moisturized air present within a water-damaged building are themselves dehumidified to liberate collected moisture through the use of ambient air drawn over and about a heat exchanger fired by diesel fuel, with a portion of the dehumidified air being diverted to join with the ambient air in increasing the liberation of the moisture within the dessicant.

Abstract: Dessicants employed in dehumidifying moisturized air present within a water-damaged building are themselves dehumidified to liberate collected moisture through the use of ambient air drawn over and about a heat exchanger fired by diesel fuel and powered by a pair of separately fused electrical circuits, one of which powers a first blower drawing ambient air from outside the building over the heat exchanger and through a dessicant in a first direction, and the other of which powers a second blower drawing moisturized air from within the building through the dessicant in a second direction.

Abstract: Dessicants employed in dehumidifying moisturized air present within a water-damaged building are themselves dehumidified to liberate collected moisture through the use of ambient air drawn over and about a heat exchanger fired by diesel fuel, with the dessicants, the dehumidifying apparatus and the diesel fuel all being carried on a trailer, with the diesel fuel inside under a skid and with its own portable electric panels with ground fault interrupters aboard in bringing its own electric power to the scene of the water-damaged building.

Abstract: A heat pump type air conditioner having an improved defrosting structure and a defrosting method for the same. When frost is not excessively accumulated on piping of an outdoor heat exchanger, a solenoid valve is controlled such that warm refrigerant from a compressor intermittently passes through a second pipe line, a heat discharging pipe line, and a third pipe line. When the air conditioner is operated in heating mode, the amount of frost accumulated on the outdoor heat exchanger is deduced from the temperature of the piping of the outdoor heat exchanger, and then a defrosting operation is performed based on the temperature of the piping of the outdoor heat exchanger. Consequently, the frost accumulated on the outdoor heat exchanger is quickly removed based on the amount of frost accumulated on the outdoor heat exchanger, and the period of time for which the air conditioner is not operated is reduced, whereby more comfortable and pleasant heating function is provided to a user.

Abstract: The proposed design describes a refrigeration system with an evaporator, which allows inherent absorption of heat from the ambient, a condenser returning refrigerant to a liquid state, a compressor delivering refrigerant within the system but with refrigerant flowing through a heat exchanger from the compressor to the receiver and flowing through such a heat exchanger parallel to the flow of low pressure gas leaving the evaporator in a vertical configuration which precludes the flow of liquid from the evaporator to the compressor but maintains the constant pressures and constant flow of refrigerant within the heat exchanger to maximize the efficiency of the system.

Abstract: A refrigerant cycling device is provided, wherein a compressor comprises an electric motor element, a first and a second rotary compression elements in a sealed container. The first and the second rotary compression elements are driven by the electric motor element. The refrigerant compressed and discharged by the first rotary compression element is compressed by absorbing into the second rotary compression element, and is discharged to the gas cooler.

Abstract: The invention relates to a heating/cooling circuit for a motor vehicle comprising an evaporator (14) for cooling air to be fed into an interior space, a heat exchanger (16) for heating said air to be fed into the interior space, an external heat exchanger (22) comprising a compressor for transporting coolant, a first expansion organ (28), allocated to the evaporator (14), a second expansion organ (30), allocated to the external heat exchanger (22) and coolant conduits (L1 to L12), via which the aforementioned components are interconnected. The compressor (24), the external heat exchanger (22) and the second expansion organ (30) constitute a de-icing circuit of the inventive circuit.

Abstract: A drive for a vehicle HVAC vent door includes a drive transmission mounted within the shaft for the vent door. The drive transmission is of the sort commonly known as a wave drive transmission, wherein a lobed member is driven by an oblong drive shaft. The lobed member selectively drives an externally threaded flex ring that in turn engages an internally toothed drive transmission member. The internally toothed drive transmission member drives the shaft for the vent door. In this fashion, a relatively small motor is provided which has sufficient power to drive the vent door. Further, an electrical connection for supplying control signals is mounted at one end of the shaft and has a non-symmetrical configuration such that the motor and vent door will be properly orientated and relative to the vehicle.

Abstract: A defrost refrigeration system having a main refrigeration system and comprising a first line extending from a compressing stage to an evaporator stage and adapted to receive refrigerant in high-pressure gas state from the compressing stage. A first pressure reducing device on the first line is provided for reducing a pressure of the refrigerant in the high-pressure gas state to a second low-pressure gas state. Valves are provided for stopping a flow of the refrigerant in a first low-pressure liquid state from a condensing stage to evaporators of the evaporator stage and directing a flow of the refrigerant in the second low-pressure gas state to release heat to defrost the evaporators and thereby changing phase at least partially to a second low-pressure liquid state. A second line is provided for directing the refrigerant having released heat to the compressing stage, the condensing stage or the evaporator stage.

Abstract: A work vehicle having a body and a heater A/C unit disposed inside the body with a condenser assembly connected to the heater A/C unit has the condenser assembly disposed on a lateral side of the body, the condenser assembly includes: a first mounting bracket disposed on the side of the body; a second mounting bracket disposed on the side of the body; a third mounting bracket disposed on the side of the body; and a planar condenser disposed in a frame, wherein the frame is pivotally connected on a first side to the first mounting bracket, and a second side opposite to the first side has a right wing and a left wing, wherein the second mounting bracket detachably connects to the left wing and the third mounting bracket detachably connects to the right wing, and the condenser is connected to the heater A/C unit by a conduit.

Abstract: A refrigeration unit is provided with a manually operated fresh air vent made up of a cap assembly and a handle assembly which move together in a linear/axial direction. The handle assembly is rotatable to change the position of the fresh air vent. The fresh air vent controls both the providing of fresh air to the circulating air in the trailer and the exhausting of a portion of the circulating air. The evaporator fan is run continuously when the air vent is open to prevent the build up of gases produced by the perishable cargo.

Abstract: A method and apparatus for controlling the temperature of a cold plate is disclosed. The temperature of the cold plate is controlled by directing compressed refrigerant along a first path configured to supply cooled refrigerant to the evaporator of the cold plate, redirecting at least a portion of the compressed refrigerant along a second path configured to supply non-cooled refrigerant to the evaporator of the cold plate, comparing a temperature reading associated with the cold plate to a predefined temperature range, and incrementally controlling the portion of the compressed refrigerant redirected along the second path responsive to the compared temperature reading. The temperature of the cold plate may be controlled to defrost the cold plate by redirecting substantially all of the compressed refrigerant along the second path for a predefined period of time responsive to a shutdown indicator.

Abstract: In a heat pump apparatus having a refrigerating cycle including a compressor 1, a gas cooler 3, a pressure reducing device 5 and an evaporator 7 in which water can be heated by the gas cooler, the compressor 1 comprises a two-stage compression type compressor for leading all or a part of refrigerant compressed to an intermediate pressure at a first stage through a shell case 11 to a second stage, compressing the intermediate-pressure refrigerant to a high pressure at a second stage and discharging the high-pressure refrigerant, and there is equipped a defrosting circuit 33 for leading the intermediate-pressure refrigerant of the first stage of the compressor 1 to the evaporator 7 with bypassing the gas cooler 3 and the pressure reducing device 5.

Abstract: A vapor compression system including a refrigerant circuit having operably coupled thereto, in serial order, a compressor, a first heat exchanger, an expansion device, and a second heat exchanger. A valve is disposed within refrigerant circuit between first heat exchanger and expansion device, and has a first position and a second position. A defrost circuit having operably coupled thereto a third heat exchanger defines an inlet in fluid communication with refrigerant circuit through valve when valve is in second position, and an outlet disposed in refrigerant circuit between inlet and expansion device. A check valve is disposed in defrost circuit between third heat exchanger and outlet. The check valve allows refrigerant to return to refrigerant circuit through outlet and prevents refrigerant from entering third heat exchanger via outlet. The refrigerant flows through third heat exchanger and second heat exchanger when valve is in second position.

Abstract: An air conditioner comprising an outdoor unit and an indoor unit provided with an indoor heat exchanger and an indoor expansion device, wherein the outdoor unit comprises a compressor for compressing a refrigerant, an outdoor heat exchanger for heat-exchanging a refrigerant, a four-way valve adjacently arranged to the compressor for circulating a refrigerant discharged from the compressor according to a heating cycle or a cooling cycle, and a refrigerant detouring path for detouring a refrigerant discharged from the outdoor heat exchanger to the compressor at the time of a defrosting operation, thereby performing the defrosting operation without stopping the heating cycle and thus preventing an indoor heating loss.

Abstract: Heating/defrost constructions of a very low temperature refrigeration system having a defrost supply circuit and a defrost return bypass circuit optimizing the heating/defrost cycle, preventing overload (excessive pressure) of its refrigeration process and protecting components from damaging temperatures. The defrost cycle operates continuously, when required, and provides a shorter recovery period between heating/defrost and cooling operating modes. The rate of the temperature change during cool down or warm up is controlled in an open loop fashion by controlled refrigerant flow in bypass circuits.

Abstract: An air conditioner comprising an outdoor unit and an indoor unit provided with an indoor heat exchanger and an indoor expansion device, wherein the outdoor unit comprises a compressor for compressing a refrigerant, an outdoor heat exchanger for heat-exchanging a refrigerant, a four-way valve adjacently arranged to the compressor for circulating a refrigerant discharged from the compressor according to a heating cycle or a cooling cycle, and a refrigerant detouring path for detouring a refrigerant discharged from the outdoor heat exchanger to the compressor at the time of a defrosting operation, thereby performing the defrosting operation without stopping the heating cycle and thus preventing an indoor heating loss.