Abstract: A refrigerator of the present disclosure can include an ice making cell, a heater configured to supply heat to the ice making cell during an ice making process, and a controller configured to control the heater. The process for controlling the heater includes a basic heating process and an additional heating process that is performed after the basic heating process. In the basic heating process, the controller performs control so that a heating amount of the heater varies according to a mass per unit height of water in the ice making cell. In at least partial section of the additional heating process, the controller controls the heater to operate with a heating amount that is equal to or less than a heating amount of the heater in the basic heating process.

Abstract: Disclosed herein is a water purifier, in which a partitioning container is detachably mounted on the bottom surface of a tank cover, and an agitator is inserted into the partitioning container to be connected to an agitating motor mounted in the tank cover in a state where the partitioning container is mounted on the bottom surface of the tank cover. By this structure, the inner diameter of the partitioning container may be less than the outer diameter of the blade of the agitator.

Abstract: An ice making machine having a refrigeration system designed for hydrocarbon (HC) refrigerants, and particularly propane (R-290), that includes dual independent refrigeration systems and a unique evaporator assembly comprising of a single freeze plate attached to two cooling circuits. The serpentines are designed in an advantageous pattern that promotes efficiency by ensuring the even bridging of ice during freezing and minimizing unwanted melting during harvest by providing an even distribution of the heat load. The charge limitations imposed with flammable refrigerants would otherwise prevent large capacity ice maker from being properly charged with a single circuit. The ice making machine includes a single water circuit and control system.

Abstract: Disclosed herein is a refrigerator in which a cold storage material suitable for a freezing chamber may be packed in a cool pack for the freezer section and/or the refrigerator section to keep the respective sections cooler if there is a power failure.

Abstract: An automatic descale and sanitize process for an ice maker which requires less user intervention and time. During descaling, a main water reservoir of an ice maker sump is filled with water to a descale water level and mixes with a cleaner placed in the main water reservoir. The water/cleaner mixture is pumped through the ice maker to descale the water system and freeze plate. During sanitizing, the sump is filled with water to a sanitize water level, above the descale water level, and mixes with sanitizer placed in a sanitizer reservoir of the sump. The water/sanitizer mixture is pumped through the ice maker to sanitize the water system and freeze plate. During descaling, the sanitizer placed in the sanitizer reservoir does not come into contact with the water in the main water reservoir. After the descale and sanitize process, the ice maker can return to making ice.

Abstract: A water dispenser for a refrigerator including a water discharge nozzle fluidly connected to a water source, a valve configured to selectively block the fluid connection, and an actuator operated to allow water to be dispensed. The water discharge nozzle is pivotally mounted to a surface of the refrigerator to pivot between a retracted position and an extended position. In the extended position, the water discharge nozzle is extended outwards beyond the surface of the refrigerator. The water discharge nozzle is biased towards one of the extended and retracted positions. The valve is configured to block the fluid connection between the water discharge nozzle and the water source when the water discharge nozzle is in the retracted position. When the water discharge nozzle pivots to the extended position, the valve is operated to enable fluid connection between the water discharge nozzle and the water source.

Abstract: A refrigeration appliance includes an ice maker is disposed within a freezer compartment. The ice maker includes a water fill assembly for conveying water from a source of pressurized water to an ice tray. The water fill assembly includes a water fill tube fluidly connected to the source of pressurized water. A removable fill and heater assembly includes a plate disposed above the ice tray of the ice maker. The plate has an opening positioned above the ice tray. A shroud extends from an upper surface of the plate and has an inlet end fluidly communicating with the water fill tube. An outlet end of the shroud directs water into the ice tray in a predetermined direction. A heating element is disposed on the upper surface of the plate for applying heat to the plate to maintain a portion of the plate at a temperature in excess of 0° C.

Abstract: A refrigerator that has a fresh food compartment, a freezer compartment, and a door that provides access to the fresh food compartment is disclosed. An icemaker is mounted remotely from the freezer compartment. The icemaker includes an ice mold. A thermoelectric device is provided and includes a warm side and an opposite cold side. The icemaker is thermally influenced by the cold side of the thermoelectric device. Air or fluid may be moved from the fresh food compartment across the warm side of the thermoelectric device. Cold air or fluid, such as from the refrigerator compartment, is used to dissipate heat from the warm side of the thermoelectric device for cooling the ice mold of the icemaker.

Abstract: Disclosed is a refrigerator. The refrigerator includes a first compressor (100) configured to compress refrigerant, a first condenser (110) configured to condense the refrigerant compressed in the first compressor (100), a first expansion valve (120) configured to reduce a temperature and pressure of the refrigerant condensed in the first condenser (110), a first evaporator (140) configured to evaporate the refrigerant having passed through the first expansion valve (120), a second compressor (200) configured to compress refrigerant, a second condenser (210) configured to condense the refrigerant compressed in the second compressor (200), a second expansion valve (220) configured to reduce a temperature and pressure of the refrigerant condensed in the second condenser (210) and a second evaporator (230) configured to evaporate the refrigerant having passed through the second expansion valve (220).

Abstract: An ice maker is provided that includes a tray having recesses that can include ice-phobic surfaces. The ice-phobic surfaces may include ice-phobic coatings, textured metal surfaces, hydrophobic coatings or other surfaces configured to repel water and ice. The tray can be formed from metal material and may exhibit a fatigue limit greater than about 150 Megapascals (MPa) at 105 cycles. The ice maker further includes a frame body coupled to the tray, and a driving body that is rotatably coupled to the tray. The driving body is further adapted to rotate the tray in a clockwise and/or counter-clockwise cycle such that the tray presses against the frame body in a manner that flexes the tray to dislodge ice pieces formed in the recesses of the tray.

Abstract: An ice making device includes heating and cooling elements that control the formation of ice within a cavity. The ice making device may include one or more fluid inlets that supply liquid water to the cavity, and one or more fluid outlets that drain water from the cavity after formation of ice having a desired shape.

Abstract: A cryogenic system to remove energy includes a heat engine to store content at a predetermined temperature; one or more fans to deliver air flow through the heat engine; a cryogenic storage unit to store cryogen and having one or more insulated pipes thermally coupled to the heat engine to cool the heat engine; one or more reuse pipes coupled to one or more insulated pipes to send a portion of cryogen gas flow back to the cryogenic storage for reuse; a controller to maintain the predetermined temperature; and an on-board power generator to supply operating power to the controller and the one or more fans.

Abstract: Embodiments of the present technology are directed to devices, systems, and methods of delivering ice under high ambient temperatures. A transportable container houses an air-conditioning system with a cascade heat exchanger coupling the air-conditioning system with a separate refrigeration system in the container. The separate refrigeration system provides cooling energy for a cooling device while rejecting a heat load to the air-conditioning system for rejection to ambient temperatures.

Abstract: The disclosure includes a water tray member receiving raw water for ice-making from a water tank, an ice making unit cooling the raw water received in the water tray member and forming ice, a heating unit heating the raw water received in the water tray member, and a control unit controlling an operation of the heating unit such that the raw water received in the water tray member is heated before the ice making unit cools the raw water in the water tray member. According to the ice maker, the temperature of the raw water received in an ice-making water tray is raised to a preset temperature at the initial stage of an ice making process, thereby preventing the formation of an opaque layer in the central portion of ice.

Abstract: An ice-making unit, which uses a cooling unit in which a refrigerant pipe is received, and a refrigerator having the same. The cooling unit includes a cooler for conduction of coldness, an inner surface of the cooler coming into direct contact with the refrigerant pipe, realizing a direct cooling type ice making operation. A rotatable tray is provided under the cooling unit, so that an ice-separating member attached to the cooling unit pushes ice upon rotation of the tray, allowing the ice to be discharged in a direction opposite to the rotating direction of the tray.

Abstract: A refrigerator is provided that includes an apparatus for producing ice comprising a reservoir that contains water, at least one freezing member, a power source, and at least one fin located on the reservoir. The at least one freezing member is located at least partially in the reservoir. The at least one freezing member is configured for forming ice by freezing the water along the periphery of the at least one freezing member. The power source is configured to move the reservoir to create a movement of the water about the at least one freezing member. The at least one fin located on the reservoir is configured for enhancing the movement of the water about the at least one freezing member and for restricting a splashing of water from the reservoir.

Abstract: A method of making ice in an ice making machine comprising: (a) compressing vaporized refrigerant, cooling the compressed refrigerant to condense it into a liquid, feeding the condensed refrigerant through an expansion device and vaporizing the refrigerant in an evaporator to create freezing temperatures in an ice-forming mold to freeze water into ice in the shape of mold cavities during an ice making mode; (b) heating the ice making mold to release the ice therefrom in a harvest mode by separating vaporous and liquid refrigerant within a receiver interconnected between the condenser and the expansion device and feeding vapor from the receiver to the evaporator, wherein the ice-forming mold, evaporator and receiver are disposed in an ice machine unit, and the compressor and condenser are disposed in a condensing unit; (c) determining if the ice making machine is on and if an ice bin switch is closed: if the ice machine is on and the bin switch is closed, then check a low pressure switch: if the low pressure s

Abstract: An ice making device includes heating and cooling elements that control the formation of ice within a cavity. The ice making device may include one or more fluid inlets that supply liquid water to the cavity, and one or more fluid outlets that drain water from the cavity after formation of ice having a desired shape.

Abstract: An improved electrical equipment housing which includes an oil sample valve and a gas port assembly which are contained within the electrical equipment housing, yet are separated from electrical contacts and may be accessed without exposure to the electrical contacts.

Abstract: Provided is a refrigerator configured to improve the structure of an ice-making chamber provided to a refrigerator door, thereby efficiently supplying cool air into the ice-making chamber. The refrigerator includes a main body including a storage chamber, a refrigerator door rotatably coupled to the main body, an ice-making device provided to the refrigerator door and configured to make ice, an ice-making unit provided to the ice-making device and including a cool air introduction part, a freezing core vertically arranged in the ice-making unit and cooled by cool air, and an ice tray configured to receive at least one portion of the freezing core therein, wherein the cool air introduction part is provided on an upper side of the freezing core. Cool air is efficiently introduced into the ice-making chamber, thereby increasing the amount of ice made.

Abstract: Provided is a method and system for forming ice pieces with an ice maker that includes a mold defining a plurality of cavities for receiving water to be frozen into ice pieces. A processor controls delivery of a refrigerant to freeze water received in the plurality of cavities into ice pieces. A freeze signal transmitted by a temperature sensor embedded within the mold is received by the processor, the freeze signal indicating that a temperature of a portion of the mold adjacent to the temperature sensor has reached a freeze temperature where the water in at least one of the cavities has achieved a frozen state to initiate harvesting of the frozen ice pieces. Defrosting a system evaporator can also be coordinated with operation of the ice maker.

Abstract: An apparatus for rapidly cooling beer flowing from a keg to a tap to be dispensed includes an insulated ice chest containing an open topped swirl pot in which is nested a cooling coil having an inlet connected to a keg and an outlet connected to a tap on a hollow upright structure fixed to the outside of an ice chest lid. A pump is connected to a stand pipe within the coil directing a flow of ice water under pressure to generally tangentially directed nozzles within the coil creating a swirl flow of ice water over the coil turns and overflowing back into the ice chest interior space holding ice to create a circulation therein maximizing the rate of cooling of the dispensed beer to minimize foaming when dispensed from the tap. A CO2 tank is also held in the ice chest interior space, connected to the keg via fluid lines and simplified hook ups to the keg are located on the lid mounted hollow structure.

Abstract: A clogging detecting apparatus for a dryer is provided that checks and displays a clogging degree of an air passage. The clogging detecting apparatus includes a judgment device for judging the clogging degree of the air passage, a storing device for storing the clogging degree of the air passage, and a display for displaying the clogging degree to the user. The clogging detecting apparatus provides information on the clogging degree, so that the user precisely checks the state of the air passage.

Abstract: A sensor assembly for detecting ice crystal formation on a heat exchange surface in an ice-making machine comprises at least one microphone monitoring the sound made by a rotating blade assembly within the ice-making machine during ice slurry formation. A filter filters the output of the microphone to remove background noise. A comparator receives the output of the filter and compares the filtered microphone output with a threshold to determine if the filtered microphone output signifies ice crystal formation on the heat exchange surface. The operation of the ice-making machine can then be adjusted in a manner to allow the formed ice crystals to be removed from the heat exchange surface.

Abstract: An electronic control for the operation of a beverage dispenser of the refrigerated ice bank type is shown. The control provides for reliable determinations of when ice production is needed and when it is not needed. A microprocessor receives information from an ice bank probe and from a temperature probe located within the ice bank. Data collected by the microprocessor from both the ice bank probe and the temperature probe is used to determine if the ice bank is either insufficient in size and should be increased or is of sufficient size such that the compressor can be turned off. A carbonator level probe is also shown and connected to the microprocessor. The microprocessor is programmed whereby the carbonator probes are sampled in a manner to accurately determine the level of water in the carbonator and therefore the need for turning on or turning off any water pump connected thereto.

Abstract: An electronic control for the operation of a beverage dispenser of the refrigerated ice bank type is shown. The control provides for reliable determinations of when ice production is needed and when it is not needed. A microprocessor receives information from an ice bank probe and from a temperature probe located within the ice bank. Data collected by the microprocessor from both the ice bank probe and the temperature probe is used to determine if the ice bank is either insufficient in size and should be increased or is of sufficient size such that the compressor can be turned off. A carbonator level probe is also shown and connected to the microprocessor.

Abstract: The present invention provides an improved system and method for sensing the presence of ice, particularly applicable in the control of ice thickness in machines employing an ice bank such as a commercial beverage chiller. The chiller may be of the conventional type having a water bath with a cold element at least partially submerged therein. The cold element is cooled by a refrigerant such as freon to the point where ice forms and grows on the element, thereby forming an ice bank in the water bath. A temperature sensor, which preferably is a thermistor-type sensor comprising a bead disposed in a metal housing, is mounted on a carrier to allow the position of the sensor to be adjustable relative to the cold element. Circuitry is provided which is operative to detect the presence of ice by sensing a temperature signal from the temperature sensor and to control the thickness of the ice bank. A method of controlling the thickness of an ice bank is also disclosed.

Abstract: An electronic control for the operation of a beverage dispenser of the refrigerated ice bank type is shown. The control provides for reliable determinations of when ice production is needed and when it is not needed. A microprocessor receives information from an ice bank probe and from a temperature probe located within the ice bank. Data collected by the microprocessor from both the ice bank probe and the temperature probe is used to determine if the ice bank is either insufficient in size and should be increased or is of sufficient size such that the compressor can be turned off. A carbonator level probe is also shown and connected to the microprocessor.

Abstract: The present invention provides an improved system and method for sensing the presence of ice, particularly applicable in the control of ice thickness in machines employing an ice bank such as a commercial beverage chiller. The chiller may be of the conventional type having a water bath with a cold element at least partially submerged therein. The cold element is cooled by a refrigerant such as freon to the point where ice forms and grows on the element, thereby forming an ice bank in the water bath. A temperature sensor, which preferably is a thermistor-type sensor comprising a bead disposed in a metal housing, is mounted on a carrier to allow the position of the sensor to be adjustable relative to the cold element. Circuitry is provided which is operative to detect the presence of ice by sensing a temperature signal from the temperature sensor and to control the thickness of the ice bank. A method of controlling the thickness of an ice bank is also disclosed.

Abstract: The present invention provides an improved system and method for sensing of ice, particularly applicable in the control of ice thickness in automatic ice-making machines. The ice-making machine may be of the conventional type using a cold plate with water flowing over it. A thermistor bead temperature sensor is encapsulated in a metal housing, which is in turn mounted on a carrier. The position of the carrier is adjustable relative to the cold plate. The control system has several variable delays or time durations which optimize system performance: 1. Minimum harvest time delay, relative to the start of the ice-making cycle; 2. Threshold persistence time delay, requires that the signal sensor persists above the harvest threshold value for a certain amount of time (referenced to when the threshold is first exceeded), before harvesting may begin; 3. Harvesting delay is an optional delay provided give the option of making sure the ice is sufficiently “cured.

Abstract: The present invention provides an improved system and method for sensing of ice, particularly applicable in the control of ice thickness in automatic ice-making machines. The ice-making machine may be of the conventional type using a cold plate with water flowing over it. A thermistor bead temperature sensor is encapsulated in a metal housing, which is in turn mounted on a carrier. The position of the carrier is adjustable relative to the cold plate. The control system has several variable delays or time durations which optimize system performance: 1. Minimum harvest time delay, relative to the start of the ice-making cycle; 2. Threshold persistence time delay, requires that the signal sensor persists above the harvest threshold value for a certain amount of time (referenced to when the threshold is first exceeded), before harvesting may begin; 3. Harvesting delay is an optional delay provided give the option of making sure the ice is sufficiently “cured.

Abstract: Accurate sensing of ice readiness in an ice maker is accomplished using, as an ice readiness sensor, a capacitance bridge circuit having a first capacitor connected as a first bridge arm a second capacitor connected as a second bridge arm, a tunable capacitor connected as a third bridge arm and a probe connected as a fourth bridge arm. The probe includes a pair of electrode strips placed in close proximity to the belt of a belt ice maker. First and second bridge arms are connected at a first bridge node first and third bridge arms are connected at a second bridge node, second and fourth bridge arms are connected at a third bridge node, and third and fourth bridge arms are connected at a grounded fourth bridge node. The first and fourth bridge nodes are input terminals for receiving an AC drive signal from an AC source, and the second and third bridge nodes are output terminals.

Abstract: The invention relates to a flake ice machine, comprising an evaporating cylinder (1) and an evaporating pan (2), wherein a sensor is provided to monitor the filling time of the evaporating pan (2), the production of ice and the water level of the water bath (3) available in the evaporating pan (2).

Abstract: A fuzzy control apparatus and method for a branched refrigerant flow and fuel combustion in a multi absorption type-heat pump is disclosed. The heat pump is controlled by automatically determining the operation state of an outdoor unit in relation to indoor loads.

Abstract: A fault restart routine for an icemaker having a microprocessor-based system controller. The fault restart routine provides at least a limited number of attempts at automatically restarting the icemaker after a shutdown has occurred because of a detected fault condition. If the fault condition is not a water inlet fault, the routine waits a first predetermined period of time before attempting to restart the icemaker. If the fault is detected as being a water inlet fault, then the system controller waits for a second predetermined time period before restarting the icemaker. If after restarting the icemaker, the icemaker completes one complete cycle of operation (i.e., a complete FREEZE cycle and a complete HARVEST cycle), then the fault restart routine is exited and a previously generated fault code is cleared.

Abstract: A system for detecting the formation of ice on a cold surface includes an electrical circuit for sensing the electrical responsiveness of a capacitor formed by a conductive plate positioned opposite the cold surface. The ice formed on the cold surface will eventually comprise most of the dielectric medium between the conductive plate and the cold surface thereby providing a distinctively recognizable electrical response that is sensed by the electrical circuit.

Abstract: An ice making machine detects when to harvest the ice being formed on an ice forming plate. A circuit analyzes the response of a capacitor formed by the ice forming plate and a conducting plate positioned opposite the ice forming plate wherein the dielectric medium therebetween substantially consists at some point in time of the ice formed on the ice forming plate.

Abstract: A method and system for electronically controlling the location of the formation of ice within a closed loop water circulating unit. A method and system is provided for making ice using supercooled water. When a desired degree of supercooling is reached in the closed loop water circulating unit, a pump associated with the ice-making machine is stopped so as to initiate ice seeding on the ice mold. After the pump is restarted, the supercooled water flows over the seeded molds to rapidly form ice on the ice molds. A method and system is also provided for improving the clarity of the ice. Water is preheated prior to introducing the water to the closed loop water circulating unit. Furthermore, in an ice-making machine having two or more ice molds, a method and system is provided for allowing one mold to act as a condenser in a harvest mode, while simultaneously allowing the remaining molds to act as evaporators in the freezing mode.

Abstract: A sensor arrangement principally for ice bank control using a single probe (9) allowed to resonate at its natural resonant frequency. That resonant frequency is different when ice has adhered to the probe and this is detected to indicate ice growth in the ice bank. A resonator/detector (11) oscillates the probe for short periods of time at regular intervals, which allows ice to form about the probe when not in oscillation.

Abstract: Disclosed is a mechanism for detecting completion of ice formation and for preventing such opacification of ice pieces in an ice making machine, in which a multiplicity of freezing fingers formed on the lower surface of a freezing base plate are dipped in the water supplied to a freezing chamber defined in a water tray to carry out a freezing operation and form inverted dome-shaped ice pieces gradually around the freezing fingers; characterized in that the mechanism consists of a rocking plate which is rocked with respect to the freezing fingers by a rocking means; and a position detector which is actuated when a predetermined size of ice pieces are formed around the freezing fingers, and the rocking plate is brought into contact with these ice pieces.

Abstract: Methods are disclosed for preparing ice, comprising guiding a liquid (22) over an evaporator (11, 12) of a refrigerating circuit (1), heating the evaporator (11, 12) at a determined moment, and collecting ice removed from the evaporator (11, 12). These methods are characterized in that the heating time and the freezing time are governed by the presence and thickness of ice on the evaporator (11, 12), respectively. Also a device for performing these methods is described, comprising a refrigerant condition sensor (28) arranged in the refrigerating circuit (1).

Abstract: The device contains a frame, a refrigeration mechanism with an evaporator, a mechanism to slightly defrost the ice formed around the protruding parts and to cause it to fall off, a water tank that is movably mounted on the frame, a water supply pipe which is located above the tank, a mechanism for moving the tank from an uppermost position around the above-mentioned protruding parts to a lowest position and vice versa, a mechanism for controlling the refrigeration mechanism and control the mechanism for moving the tank, and an upper grid that is hingedly mounted on the frame, is pushed up by the movement of the tank from its lowest to its uppermost position and protrudes before the uppermost position of the tank on the top in such a manner between the downward directed protruding parts of the evaporator that, when ice cubes are formed around these protruding parts already situated above all these ice cubes and cannot go down as long as all ice cubes have not fallen off, while the mechanism which controls the

Abstract: An assembly, especially for a beverage-vending machine with a container for the storing, cooling and carbonating of water including two measuring electrodes arranged in the container at differing horizontal and vertical distances from an electrically conductive inner wall of the container connected to ground, one of these in the area of the ice layer under formation. The measuring electrodes obtain resistance values for the ice and/or water that arise between the electrode and the inner wall of the container. In order to cool the water independently from its physical-chemical composition, potentials corresponding to the resistances are derived and are supplied to a differential amplifier. Depending on a size comparison of the two resistance values, a cooling apparatus that affects the contents of the container is switched on or off.

Abstract: An ice maker including freeze and harvest controls is disclosed. The evaporator includes a unitary evaporator and ice mold. A compressor and condenser cool the evaporator to freeze ice on the mold in a normal refrigeration cycle and the mold is defrosted by hot gas to harvest ice from the ice mold. The temperature of the ice mold and the liquid line temperature of the condenser are sensed to control the length of time of the ice forming cycle.

Abstract: An ice maker including freeze and harvest controls is disclosed. The evaporator includes a unitary evaporator and ice mold. A compressor and condenser cool the evaporator to freeze ice on the mold in a normal refrigeration cycle and the mold is defrosted by hot gas to harvest ice from the ice mold. The temperature of the ice mold and the liquid line temperature of the condenser are sensed to control the length of time of the ice forming cycle.

Abstract: A data drive type air conditioner control apparatus includes a main controller for controlling an air conditioner having a plurality of control modes and including an operation procedure memory for storing control operation procedures corresponding to the respective control modes of the air conditioner, and a control data memory for storing numerical data to be used for the control of the air conditioner and including a numerical data memory for initially storing numerical data to be used for controlling the drive of the air conditioner, such that the main controller drives the air conditioner in accordance with the numerical data stored in the control data memory.

Abstract: Disclosed is an automatic ice making machine having an ice making section, a water feed system, an ice releasing unit and an ice removal detector; characterized in that said ice making machine further comprises a protection unit which stops the ice making operation after a predetermined time counted from the starting point of the ice releasing operation, provided that the ice removal detector outputs no ice removal signal.

Abstract: An ice bank control system for a beverage dispenser having a mechanical refrigeration system including an inexpensive solid state sensor, preferably a thermistor, located in the ice water bath adjacent to the evaporator coil and connected to a control circuit including a microprocessor which not only controls the ice bank, but also protects the compressor motor. The resistance of the thermistor is measured and then compared to a reference value previously stored in the microprocessor memory.

Abstract: Ice making apparatus includes surfaces on which ice pieces form when water is sprayed on those surfaces, a water reservoir and a pump to pump water from the reservoir for spraying onto those surfaces, and a pressure sensitive control which responds to pressure of water in the reservoir, communicated via an air duct to a pressure switch, to control operation of the pump, the switch being adjustable to adjust the sizes of ice pieces formed on the surfaces.

Abstract: A refrigerant piping system for a refrigeration machine includes an injection pipe connected at one end thereof with the suction port of a compressor and at the other end with the outlet port of a condenser. The injection pipe is provided with a solenoid valve for suppressing a coolant from flowing into the compressor during a heating operation of the machine. By closing the solenoid valve during the heating operation, the liquid coolant is prevented from flowing into the compressor through the injection pipe.