Abstract: A refrigeration system with integrated accumulator-expander-heat exchanger is disclosed. Refrigerant from a condenser/gas cooler is throttled through a capillary tube while at the same time undergoing a heat exchanging process with refrigerant from an evaporator. This method can elevate the compressor efficiency, increase the specific cooling capacity, and enhance the system performance. The capillary tube, which has dual functions of expansion device and heat exchanger, is placed inside a canister which also functions as an accumulator. The new device combining three separate parts into one can simplify the manufacturing process, lower the system size and weight, and thus decrease cost of the whole system.

Abstract: A refrigeration apparatus includes two sub passages which are branched from a main passage located between a condenser and an expansion part and which are connected to a compressor. On the sub passages are provided supercooling-use expansion parts, and supercooling-use heat exchangers for performing heat exchange between a refrigerant on an outlet side of the supercooling-use expansion part and a refrigerant of the main passage. Therefore, each time the refrigerant of the main passage passes through the two supercooling-use heat exchangers the degree of liquid supercooling of the refrigerant is increased.

Abstract: A refrigerant system is provided with an expansion device that may be a thermostatic expansion device or an electronic expansion device. A bypass line selectively allows a portion of refrigerant to bypass the expansion device and to flow through a fixed restriction expansion device such as an orifice positioned in parallel configuration with the main expansion device. A valve selectively enables or blocks refrigerant flow through this bypass line depending on the volume of refrigerant required to circulate through the refrigerant system as defined by environmental conditions and a mode of operation. The valve can be a simple shutoff valve or a three-way valve selectively allowing or blocking refrigerant flow through a particular refrigerant line or lines. In one embodiment, the expansion device is the main expansion device for the refrigerant system. In the other embodiment, the expansion device is a vapor injection expansion device for expanding refrigerant for performing an economizer function.

Abstract: A defrost refrigeration system of the type having a main refrigeration circuit operating a refrigeration cycle. The defrost refrigeration system comprises a first line extending from the first compressor to the evaporator stage and is adapted to receive a portion of discharged low-pressure refrigerant from the first compressor. Valves are provided for stopping a suction of cooling refrigerant in an evaporator of the evaporator stage and for directing a flow of defrost refrigerant to release heat to defrost the evaporator. A second line is provided for directing the refrigerant having released heat to the expansion stage of the refrigeration cycle. A pressure reducing device is optionally positioned downstream of the condensing stage for adjusting a pressure of the refrigerant in the high-pressure liquid state mixing with the defrost refrigerant having released heat.

Abstract: A HVAC system and method for a vehicle is disclosed. The air conditioning portion of the HVAC system may be able to store and release refrigerant in charge bottle while operating in an air conditioning mode. The air conditioning portion of the HVAC system may be able to employ the refrigerant flowing through the evaporator to provide supplemental heat.

Abstract: An air conditioning system includes an evaporator, a compressor, a condenser, a valve an energy recovery device and at least one bypass passage. The compressor is fluidly connected to the evaporator. The condenser is fluidly connected to the compressor. The valve is configured to control flow of high-pressure refrigerant exiting the condenser. The energy recovery device has an inlet and an outlet. The inlet is fluidly connected to the valve to receive high-pressure refrigerant and the outlet is fluidly connected to the evaporator to deliver low-pressure refrigerant thereto. The energy recovery device is configured to extract work from flow of refrigerant therethrough. When the valve is closed and refrigerant flow cutoff, suction power loss is reduced by introduction of one or both of high-pressure refrigerant or low pressure refrigerant via one or more bypass passages.

Abstract: The present invention related to cooling systems. More specifically, the present invention relates to a system for cooling one or more parts of a building and or processes comprising a compressor, a condenser having an inlet and an outlet and a plurality of condenser cooling fans, a receiver, a liquid refrigerant pump, an expansion device, an evaporator, the evaporator being surrounded by a chiller barrel having a cooled water return and a chilled water supply line, and refrigerant line means interconnecting the compressor, condenser, expansion device and evaporator in series, in a closed loop for circulating refrigerant therethrough; means for switching the cooling system between free cooling and mechanical cooling and means for actively floating the head pressure in both mechanical and free cooling modes.

Abstract: A compression refrigeration system that includes a compressor, a heat rejector, expansion means and a heat absorber connected in a closed circulation circuit that may operate with supercritical high-side pressure.

Abstract: An air conditioning system includes an air-cooling unit and an air-heating unit. On a first path in the cooling-unit, provided are a compressor for first refrigerant, a condenser for the first refrigerant, front and rear expansion units for the first refrigerant, and an front and rear evaporators to cool air. On a second path in the air-heating unit, provided are a pump for second refrigerant, and front and rear heater cores for the second refrigerant. The condenser is located also on the second path to achieve heat-exchanging between the first refrigerant and the second refrigerant. During air-heating, air heated by the front and rear heater cores is supplied to a vehicle compartment as conditioned air. During air-cooling, air cooled by the front and rear evaporator is supplied to the vehicle compartment as conditioned air.

Abstract: It is possible to prevent that a liquid refrigerant is included in a refrigerant injected into a compressor. Accordingly, the risk of liquid compression of the compressor is greatly reduced, thereby decreasing the possibility of damage to the compressor and improving reliability and performance.

Abstract: A refrigeration apparatus having a refrigerant circuit (20) for performing a vapor compression refrigeration cycle is disclosed. Refrigerant in a wet state, which provides an optimum coefficient of performance (COP) for a present operating condition, is drawn into the compressor (31). If the operating condition changes, the opening of an expansion valve (23) is adjusted such that the suction refrigerant of the compressor (31) is brought into a wet state which provides an optimum coefficient of performance for a new operating condition.

Abstract: In an apparatus comprising: an evaporator 1 for boiling and evaporating a cold/heat evaporable liquid under a reduced pressure; a condenser 2 for condensing vapor; a cold/heat indirect heat exchanger 6 at a load 14 side; a cooling heat exchanger 11 using the air; cold-heat circulation means 5 and 7 for circulating a cold/heat evaporable liquid in the evaporator to the cold/heat indirect heat exchanger; cooling circulation means 10 and 12 for circulating a cooling evaporable liquid in the condenser to the cooling heat exchanger; and a vapor compressor 20 provided in a vapor duct 19 extending from the evaporator to the condenser, a running cost is reduced when a temperature at the condenser side becomes lower than a temperature at the evaporator side due to a drop in air temperature, without a rise in a temperature of the cold/heat evaporable liquid. The vapor duct 19 is provided with a bypass vapor path 22 for bypassing the vapor compressor. The bypass vapor path is provided with an on-off valve 23.

Abstract: A direct exchange geothermal heating/cooling system has a self-adjusting expansion valve and a bypass flow path to improve efficiency when the system operates in a heating mode. The expansion valve may operate based solely on pressure from the vapor refrigerant transport line. The system may alternatively include an accumulator, a compressor, and an oil separator, wherein an oil return line returns oil from the oil separator to the accumulator. Additionally, a direct exchange geothermal heating/cooling system may include a hot-gas bypass valve for diverting heated vapor refrigerant to the liquid refrigerant line. Finally, a direct exchange geothermal heating/cooling system having a sub-surface heat exchanger extending to a depth of at least 300 feet may use a refrigerant particularly suited for such an application.

Abstract: In a refrigeration device including a refrigeration circuit having a compressor and a receiver, the present invention will improve the ability of a liquid level detection circuit to accurately determine whether or not liquid refrigerant is stored up to a predetermined position of the receiver. An air conditioner includes a main refrigerant circuit and a liquid level detection circuit. The main refrigerant circuit includes a compressor that compresses gas refrigerant, a heat source side heat exchanger, a receiver that stores liquid refrigerant, and user side heat exchangers.

Abstract: Refrigerant freezeout is prevented, and temperature is controlled, by the use of a controlled bypass flow that causes a warming of the lowest temperature refrigerant in a refrigeration system that achieves very low temperatures by using a mixture of refrigerants comprising at least two refrigerants with boiling points that differ by at least 50° C. This control capability enables reliable operation of the very low temperature system.

Abstract: A refrigeration system for use in cooling electronic equipment includes a closed vapor compression circuit having operably disposed therein a compressor, a condenser, a first expansion device, a second expansion device, and a two-part evaporator. A first part of the evaporator receives working fluid from the first expansion device at a first pressure, and a second part of the evaporator receives working fluid from the second expansion device at a second pressure that is different than the first pressure.

Abstract: A refrigerator and a control method thereof in which a smooth flow of a refrigerant can be provided through an effective control for a path change valve when a flow path of the refrigerant is changed between two evaporators having different pressures. The refrigerator includes low-pressure-side and high-pressure-side evaporators, a path change device, and a controller. The path change device changes a refrigerant flow path between the low-pressure-side evaporator and the high-pressure-side evaporator, and has a simultaneous opening stage to simultaneously establish refrigerant flow paths respectively communicating with the low-pressure-side evaporator and high-pressure-side evaporator during the path change.

Abstract: A refrigerant circuit (10) of a refrigeration apparatus is filled up with carbon dioxide as a refrigerant. In the refrigerant circuit (10), a first compressor (21) and a second compressor (22) are arranged in parallel. The first compressor (21) is connected to both an expander (23) and a first electric motor (31), and is driven by both of the expander (23) and the first electric motor (31). On the other hand, the second compressor (22) is connected only to a second electric motor (32), and is driven by the second electric motor (32). In addition, the refrigerant circuit (10) is provided with a bypass line (40) which bypasses the expander (23). The bypass line (40) is provided with a bypass valve (41). And, the capacity of the second compressor (22) and the valve opening of the bypass valve (41) are regulated so that the COP of the refrigeration apparatus is improved after enabling the refrigeration apparatus to operate properly in any operation conditions.

Abstract: A control algorithm for controlling an economizer circuit in a chiller system is provided. The control algorithm opens and closes a port valve in the economizer circuit in response to predetermined criteria to engage and disengage the economizer circuit. The predetermined criteria can include an operating parameter of a compressor and a level of liquid refrigerant in a flash tank.

Abstract: An air conditioning system includes an indoor heat exchanging unit, an outdoor heat exchanging unit, a compressor forming a closed loop together with the indoor and outdoor heat exchanging units to compress refrigerant, and a compressor driver to drive the compressor.

Abstract: A control algorithm for controlling an economizer circuit in a chiller system is provided. The control algorithm opens and closes a port valve in the economizer circuit in response to predetermined criteria to engage and disengage the economizer circuit. The predetermined criteria can include an operating parameter of a compressor and a level of liquid refrigerant in a flash tank.

Abstract: In a cooling system having a compressor for supplying refrigerant under pressure, a condenser for condensing the refrigerant supplied from the compressor, a liquid receiver arranged to temporarily store the condensed refrigerant supplied from the condenser, an expansion valve for expanding the refrigerant supplied from the liquid receiver, and an evaporator arranged to effect evaporation of the expanded refrigerant for cooling the surrounding thereof, a bypass conduit is arranged to bypass the liquid receiver and expansion valve, and an electrically operated flow passage changeover valve is provided to selectively connect a supply passage of refrigerant to the liquid receiver and expansion valve and to the bypass conduit so that the supply passage of refrigerant is connected to the liquid receiver and expansion valve during operation at a cooling mode and is connected to the bypass conduit during operation at a defrost mode.

Abstract: A system has a number of parallel flowpath segments between a compressor and an evaporator. One or more valves selectively block and unblock at least one of the segments to provide capacity control.

Abstract: A method for controlling the temperature of a coolant supplied to a process, such as a semiconductor process. The method provides for chilling a coolant to a predetermined temperature, controlling the coolant at the predetermined temperature and delivering the coolant to the semiconductor process. The method includes feedback and feed-forward control algorithms to control the temperature to within about ±0.1° C. under steady state conditions and to within about ±0.75° C. under maximum heat loading and unloading conditions. The invention may be used in any fluid or component temperature control application (e.g. semiconductor, pharmaceutical, or food applications).

Abstract: Systems and methods for heat exchange in accordance with the invention define adequately long-interchange distances for two fluids by wrapping a tube containing a first fluid about the wall of an inner cylindrical tank, within a gap formed with a second concentric tank. A second fluid is transmitted in the space defined between the turns of the tube and the two walls, providing effective short length thermal interchange through the tube walls. The tube is in the line contact with both tank walls and the fluids can flow rapidly over an adequately long length, so that high efficiency is provided in a low cost system.

Abstract: Disclosed are an air conditioner and a refrigerant control method thereof. An air conditioner according to an embodiment of the invention an outdoor unit including a compressor, an outdoor heat exchanger, and a four-way valve that switches a flow passage of refrigerant, an indoor unit including an indoor heat exchanger, an indoor expansion unit disposed at a refrigerant inlet side of the indoor heat exchanger and allowing the refrigerant to be expanded during the cooling operation, an outdoor expansion unit disposed at a refrigerant inlet side of the outdoor heat exchanger and allowing the refrigerant to be expanded during the heating operation, and a control unit controlling the indoor expansion unit and the outdoor expansion unit such that the refrigerant is expanded in the indoor expansion unit during the cooling operation and the refrigerant is expanded in the outdoor expansion unit during the heating operation.

Abstract: In a refrigerating cycle incorporating a second flow controller having a throttle section, which is composed of an inlet noise eliminating space 19, an inlet side porous permeable member 20 communicating in a refrigerant flow direction, an orifice 23, an outlet side foamed metal 25, and an outlet noise eliminating space 27, and a multi-directional valve, a gas/liquid two-phase refrigerant is caused to pass through the throttle section.

Abstract: A cooling unit wherein devices are divided so as to be installed in each of an outdoor unit and indoor unit, for downsizing the indoor unit and reducing its pipe-line cost. The cooling unit disposes a compressor, a condenser and a liquid receiver R in the outdoor unit, and disposes an expansion means and an evaporator in the indoor unit. The outdoor unit comprises a first bypass pipe closed by a first bypass valve so as to open/close freely. The indoor unit comprises a second bypass pipe, which is closed by a second bypass valve so as to open/close freely. The units are connected by a liquid pipe used as a supply line for refrigerant or hot gas by selecting a refrigerant supply line among the bypass valves and the open/close valves, and by a gas pipe communicating the evaporator to the compressor.

Abstract: A refrigeration equipment includes a vapor compression type of refrigerant circuit that prevents a decline in refrigeration ability in user side heat exchangers when the refrigerant condensed by a heat source side heat exchanger is reduced in pressure and sent to the user side heat exchangers. An air conditioner includes a refrigerant liquid junction line and a refrigeration gas junction line, a heat source side expansion valve, a cooler, and a first pressure detection mechanism. The heat source side expansion valve reduces the pressure of the refrigerant that is condensed in the heat source side heat exchanger and sent to the user side heat exchangers. The cooler cools the refrigerant that is condensed in the heat source side heat exchanger and sent to the user side heat exchangers. The first pressure detection mechanism detects the pressure of the refrigerant after the pressure thereof has been reduced by the heat source side expansion valve.

Abstract: There is provided a system and method for controlling a temperature of a refrigerant in an air conditioner, in which a supercooling degree and/or a superheating degree can be secured by controlling a difference in refrigerant temperatures of a pipe connecting one or more indoor units to one or more outdoor units, and a flow of a specific refrigerant. The system includes: one or more indoor units; one or more outdoor units; a high-pressure pipe and a low-pressure pipe for connecting the indoor units and the outdoor units; and a refrigerant temperature control unit coupled to the high-pressure pipe and the low-pressure pipe, for performing a heat exchange with respect to flowing refrigerants by coupling an inner pipe to an outer pipe, the inner pipe passing through the another pipe.

Abstract: There is disclosed a refrigerant cycle apparatus capable of avoiding occurrence of an abnormal rise in a pressure on a high-pressure side in advance, comprising: a throttling mechanism including a first capillary tube, and a second capillary tube which is connected in parallel to the first capillary tube and whose flow path resistance is smaller than that of the first capillary tube; and a valve device for controlling refrigerant circulation into the first and second capillary tubes, so that a refrigerant is passed into the second capillary tube at the time of starting of a compressor.

Abstract: A cooling circuit through which coolant flows, for use with a refrigerated cabinet. The cooling circuit includes a compressor and a condenser with a flow path extending there between. The cooling circuit also includes an evaporator and a second flow path that extends between the evaporator and the condenser. The cooling circuit additionally includes a suction accumulator and a flow path extending between the evaporator and the suction accumulator, while a fourth flow path extends between the suction accumulator and the compressor. The cooling circuit also includes a coolant bypass and a switch that switches the cooling circuit between a cycling mode and a non-cycling mode.

Abstract: Refrigerant freezeout is prevented by the use of a controlled bypass flow that causes a warming of the lowest temperature refrigerant in a refrigeration system that achieves very low temperatures by using a mixture of refrigerants comprising at least two refrigerants with boiling points that differ by at least 50° C. This control capability enables reliable operation of the very low temperature system.

Abstract: An air conditioning apparatus includes a valve for selectively introducing the coolant discharged from a compressor to either a flow path for a water-coolant heat exchanger or another flow path to avoid the heat exchanger, a thermostat for detecting the temperature of a cooling water flowing into an engine and a controller for controlling the valve. When the temperature of the cooling water is equal to or less than a predetermined temperature, the controller controls the valve so that the coolant discharged from the compressor is introduced to the water-coolant heat exchanger. When the temperature of the cooling water is more than the predetermined temperature, the controller controls the valve so that the coolant discharged from the compressor avoids the water-coolant heat exchanger.

Abstract: A refrigeration cycle system is disclosed. Upon generation of a start signal for a hot gas heater cycle, the cooling mode is first started thereby to start the dormant refrigerant recovery mode (S10) and, upon an increase in the compressor discharge pressure Pd to a predetermined setting P1, the cooling mode is ended and the compressor is switched to the off mode (S20, S30). Upon the lapse of a predetermined time ta in the off mode, the off mode is ended (S40) and the heating mode with the hot gas heater cycle is started.

Abstract: The object of the present invention is to prevent refrigerant from flowing out into a vehicle compartment due to damage to an evaporator or piping associated therewith. A solenoid valve is arranged at an inlet of an evaporator, and a check valve is arranged at an outlet of the evaporator. When operation of a system is to be stopped, the solenoid valve is closed while a compressor is kept operating for a predetermined time to suck out refrigerant from the evaporator to a downstream side of the check valve, so that during stoppage of the operation, the check valve prevents the refrigerant from flowing back into the evaporator. Thus, even if the evaporator arranged in the vehicle compartment or piping associated therewith is damaged, a situation where a large amount of refrigerant flows out of the evaporator into the vehicle compartment does not occur because no refrigerant remains in the evaporator, making it possible to prevent occupants in the vehicle compartment from being put in a grave situation.

Abstract: To provide an outflow prevention device which is capable of preventing refrigerant from flowing out into a vehicle compartment even when an evaporator has ruptured. The outflow prevention device comprises a shut valve arranged in a passage via which refrigerant introduced into a shut valve inlet from an expansion device is allowed to flow to the evaporator, and a check valve arranged in a passage via which refrigerant returned from the evaporator is allowed to flow to an accumulator. A chamber behind a piston fixed to a plug holding a valve sheet and a chamber on a downstream side of the check valve are communicated with each other via a bypass passage, so that differential pressure generated across the check valve by flow of refrigerant through the same can be applied to the shut valve to open and close the same.

Abstract: A refrigerant cycle is provided with tandem compressors. Only some of the multiple compressors are provided with an economized cycle, and an optional unloader valve for selectively returning flow from an economizer injection port back to suction. The present invention thus provides the economized operation capabilities and benefits for a refrigerant cycle having tandem compressors, without the complexity of providing separate economizer arrangement for each of the compressors.

Abstract: A vapor compression system includes a main vapor compression circuit including a compressor, a condenser, an expansion device and an evaporator serially connected by main refrigerant lines, the compressor having a main discharge port, a suction port and an economizer/bypass port, an economizer circuit connected between the condenser and the economizer/bypass port of the compressor and including an auxiliary expansion device and a heat exchanger serially connected by economizer refrigerant lines, the economizer refrigerant lines and the main refrigerant lines being exposed to each other for heat exchange in the heat exchanger; and a bypass circuit including a bypass line extending from the economizer/bypass port to the suction port, and a bypass valve positioned along the bypass line, the bypass valve being positionable between a closed position wherein the economizer circuit is active and the bypass circuit is inactive, and an open position wherein the economizer circuit is active and the bypass circuit is ac

Abstract: A refrigerant cycle includes economized tandem compressors. The refrigerant cycle is also provided with a common economizer circuit for all tandem compressors. Common manifolds communicate discharge, suction and economizer return flows within the refrigerant cycle to each of the tandem compressors. Also, an optional unloader function is provided for each of the compressors. Various arrangements allow enhanced operation control, improved system reliability and reduced equipment life-cycle cost.

Abstract: Multi-type air conditioner including an outdoor unit having a compressor, an outdoor heat exchanger, a flow path control valve for controlling a flow path of the refrigerant from the compressor, an outdoor expansion device for expanding liquid refrigerant introduced thereto in a condensed state via indoor units and providing to the outdoor heat exchanger when the room is heated, and an outdoor unit piping system, a plurality of indoor units each having an indoor expansion device, an indoor heat exchanger, and an indoor piping system, a distributor for selectively distributing the refrigerant from the outdoor unit to the indoor units and returning to the outdoor unit again proper to respective operation modes, and means for super cooling the refrigerant condensed at the outdoor heat exchanger or the indoor heat exchangers and flowed to the indoor expansion devices or to the outdoor expansion device, thereby super cooling the refrigerant supplied to the evaporator.

Abstract: A high temperature heat pump comprising a low temperature heat exchanger to produce vapor of a first fluid from heat transferred from a second fluid to a mixture of liquid and vapor of the first fluid; a compressor to increase the pressure and temperature of the produced vapor; a high temperature heat exchanger to heat the second fluid to useful, high temperatures from the condensation of the first fluid; and an expander to lower the pressure and temperature of the first fluid producing a mixture of vapor and liquid.

Abstract: Methods and related systems providing removal of heat from electric motors via fluid baths.

Abstract: In the air conditioner of the present invention, both the normal cooling mode operation, in which refrigerant discharged from the compressor 1 is made to flow in the condenser 2, and the heating mode operation conducted by the hot gas bypass, in which refrigerant is made to bypass the condenser and directly flow in the evaporator 4 via the throttle 17, can be conducted. Before this heating mode operation, after the compressor is turned on for a predetermined period of time in the cooling mode, the compressor is turned off for a predetermined period of time, so that refrigerant residing in the condenser can be recovered into the hot gas cycle, and then a hot gas operation, which is the heating mode, is conducted.

Abstract: Disclosed is a refrigerant circuit which comprises a compressor (15), a water heat exchanger (16), a receiver (18), an expansion valve (19), and an evaporator (20). In the refrigerant circuit, a refrigerating cycle is carried out by compressing refrigerant to above a critical pressure in the compressor (15). A cooling section (17) for cooling refrigerant flowing out of the water heat exchanger (16) is provided on the upstream side of the receiver (18). A part of the evaporator (20) functions as an air heat exchanger which operates as the cooling section (17). The cooling section (17) exchanges heat with refrigerant on the outlet side of the evaporator (20).

Abstract: In a hot gas heating mode of an ejector cycle system, hot gas refrigerant discharged from a compressor is introduced to an interior heat exchanger while bypassing an exterior heat exchanger. The refrigerant discharged from the interior heat exchanger can flow into an ejector from at least an inlet of a nozzle of the ejector, and flows into the gas-liquid separator, in the heating mode. Alternatively, refrigerant discharged from the compressor can be supplied to the interior heat exchanger through a clearance between an outer wall of the nozzle and an inner wall of a nozzle housing portion, while bypassing the exterior heat exchanger in the heating mode. Here, the nozzle is disposed in the nozzle housing portion, and a part of pressurizing portion is defined by the nozzle housing portion. Thus, the heating mode can be readily performed in the ejector cycle system.

Abstract: It is an object of the present invention to reduce the constraint that the density ratio is constant as small as possible, and to obtain high power recovering effect in a wide operation range by using an expander which is operated in accordance with a flowing direction of refrigerant.

Abstract: A condensing stage of a refrigeration system. The condensing stage comprises means for returning a portion of the refrigerant of the refrigeration system at a downstream end of the condensing stage in a high-pressure liquid state to an upstream end of the condensing stage, to mix the portion of refrigerant with refrigerant in the high-pressure gas state prior to being fed to the condensing stage so as to increase the amount of heat released by volume of refrigerant in the condensing stage.

Abstract: There is disclosed a refrigerant cycle apparatus capable of avoiding occurrence of an abnormal rise in a pressure on a high-pressure side in advance, comprising: a throttling mechanism including a first capillary tube, and a second capillary tube which is connected in parallel to the first capillary tube and whose flow path resistance is smaller than that of the first capillary tube; and a valve device for controlling refrigerant circulation into the first and second capillary tubes, so that a refrigerant is passed into the second capillary tube at the time of starting of a compressor.

Abstract: A refrigeration cycle system is disclosed. Upon generation of a start signal for a hot gas heater cycle, the cooling mode is first started thereby to start the dormant refrigerant recovery mode (S10) and, upon an increase in the compressor discharge pressure Pd to a predetermined setting P1, the cooling mode is ended and the compressor is switched to the off mode (S20, S30). Upon the lapse of a predetermined time ta in the off mode, the off mode is ended (S40) and the heating mode with the hot gas heater cycle is started.