Abstract: A refrigeration system has a compressor operable to supply relatively hot compressed refrigerant gas, a condenser to liquify the relatively hot compressed refrigerant gas from the compressor, a thermostatic expansion (TX) valve to vaporize liquified refrigerant from the condenser, an evaporator to cool the surrounding atmosphere by vaporized refrigerant from the TX valve, a superheat sensor to improve control of the TX valve, a compressor discharge line to convey relatively hot compressed refrigerant gas from the compressor to the condenser, a liquid line to convey liquified refrigerant from the condenser to the TX valve, and a suction line including the superheat sensor to convey vaporized refrigerant from the evaporator to the compressor.

Abstract: A defroster for a heat pump to remove frost which falls on an evaporator during a heating operation of the heat pump. The defroster includes a condenser, compressor, and a cylindrical converting valve. A by-pass tube branches off at an outlet of the compressor to induce refrigerant and an on-off valve selectively induces the refrigerant into the bypass tube. A first inlet tube is formed at an upper portion of the cylindrical converting valve for receiving refrigerant drawn by the bypass tube and a first outlet tube emits the refrigerant into an upper portion of the evaporator. A second inlet tube is formed at a lower portion of cylindrical converting valve for receiving refrigerant coming from the condenser and a second outlet tube emits the refrigerant into a lower portion of the evaporator. A converting plate, rotating in the cylindrical converting valve, connects the first inlet tube with the first outlet tube, while connecting the second inlet tube with a second outlet tube.

Abstract: A refrigeration module removably suitable for use in either a refrigerator or a freezer uses signals from a series of temperature sensors for refrigeration control. An automatic defrost cycle is initiated when the evaporator outlet temperature drops to a value equal to the inlet temperature and is accompanied by a constant or rising temperature in the refrigerated cabin to which the module is connected. Field service is limited to an exchange of modules, so that refrigerating gas is not lost into the environment.

Abstract: An icemaker incorporating a hot gas bypass system for introducing a supplemental quantity of refrigerant from a condenser into a compressor of the icemaker during a harvest cycle. The system includes a harvest bypass valve disposed in a bypass conduit coupled between an input port of the compressor and the inlet of a remotely disposed condenser. The harvest bypass valve is opened by a system controller of the icemaker during a harvest cycle which allows refrigerant in the condenser to migrate back into the input port of the compressor during the harvest cycle. In this manner, it can be insured that a sufficient quantity of refrigerant is available to carry out the harvest cycle. The adding of a supplemental quantity of refrigerant is further accomplished through a single valve and does not add appreciably to the overall cost or complexity of the icemaker.

Abstract: An air conditioning system usually referred to as an electric heat pump, which employs reverse cycle refrigeration apparatus to condition air inside a building for heating in the winter months, and for cooling in the summer months, utilizing one heat exchanger coil disposed in heat exchange relation to the flow of conditioned air circulating within a building, and two heat exchanger coils disposed in heat exchange relation to the flow of ambient air circulating outside a building, wherein each said heat exchanger coil comprises a separate and singular component part of a single air conditioning circuit connected to, and served by one single compressor; and wherein, each of the said outside heat exchanger coils are designed to change functions independent of the other, from that of an evaporator, to that of a condenser, for the purpose of inhibiting the accumulation of frost on, and/or removing frost from said outside heat exchanger coil when the heat pump is operating in the heating mode without reversing the

Abstract: The present invention relates to a method for alleviating a short-term "cold blow" effect in a heat pump heating system. According to a method of the invention, reversing of a system valve in response to the sensing of a defrost condition is delayed by a predetermined time. The amount of this delay time depends upon the amount of time required for a supplementary heating unit to achieve an output sufficient to offset the cooling effect resulting from there being a cold indoor coil.

Abstract: An apparatus for heating or cooling a space comprises a main flow loop including a compressor (1012), an outside heat exchanger (1014), an inside heat exchanger (1016) connected to allow working fluid to circulate therebetween, and a first valve (1026) between the outside heat exchanger (1014) and the inside heat exchanger (1016) selectively to block flow between the outside heat exchanger (1014) and the inside heat exchanger (1016). A first bypass line extends between the outlet of the outside heat (1014) and the inlet of the inside heat exchanger (1016). A thermal storage device (1018) is positioned in the first bypass line. A second bypass line extends between the inlet of the inside heat exchanger (1016) and the outlet of the inside heat exchanger (1016) and communicates with the first bypass line to bypass the inside heat exchanger (1016). A second valve (1030) is positioned in the second bypass line to block flow through the second bypass line selectively.

Abstract: An air conditioning apparatus for heating and cooling a room, which has a four-way valve to reverse the flow of a refrigerant, thereby switching the operation mode, heating or cooling, and which has a bypass line for bypassing an inside heat-exchanger, a control valve for controlling the flow ratio of the refrigerant passing through the bypass line and the inside heat-exchanger, and a refrigerant-heating element disposed in a line between the control valve and the compressor, thereby, in the defrosting mode, melting the frost formed on endothermic fins without cooling the room and without a liquid return to the suction side of the compressor.

Abstract: A new method and apparatus for thawing frozen food product utilizing desuperheated gas thawing medium near its saturation point. The transfer of the latent heat of condensation from the thawing medium to the frozen food product immediately condenses the thawing medium into a condensate liquid, after which it is recycled back through the refrigeration system. Since the thawing medium quickly condenses upon giving up energy to the frozen food product, it falls away from the upper surface of the thawing deck tube interiors, being replaced by additional gaseous thawing medium near its saturation point, which in turn condenses upon giving up heat, and the process continues until the food product is completely thawed. Since the state of the thawing medium is consistent throughout the thawing deck tubes, the temperature along the length of each of the tubes is uniform.

Abstract: A refrigerant evaporator has a first heat exchange portion with an uninterrupted surface formed from sheets of conductive material joined together to form passages therebetween. A second heat exchange portion is connected to and adjacent the first portion. The second portion is formed from hollow, serpentine tubes with spine fins. Condensed refrigerant passes through the first portion, which accummulates frost and ice, and then through the second portion. The first portion also includes a labyrinth of passages that define an accumulator for refrigerant that has passed through the second heat exchange portion.

Abstract: A refrigerating exchanger (1) for a refrigeration facility such as a cold storage room or a refrigerated display case, including a refrigerant or heat-removing fluid circulating assembly (5) connected to a heat exchanging assembly (6) with a large surface area. The assemblies (5, 6) form an array of several layers (7) and several rows (8) in the form of a plurality of mutually similar parallel members (9) separated by spacers (10) for providing heat insulation and collecting defrosting runoff water. Each member (9) comprises at least one layer (7) as well as a respective inlet (11) and outlet (12) forming part of the circulating assembly (5).

Abstract: The present invention provides a closed loop vapor cycle refrigeration system that includes a compressor, a condenser, an evaporator system having at least two parallel evaporator coils, means for discharging the compressed gas refrigerant into the outlet ends of each of the parallel evaporator coils and a flow control means coupled to the inlet end of each of the parallel evaporator coils. In an embodiment, a flow control valve is used as the flow control means. The flow control valves are independently controlled by a control circuit. During the defrost cycle, the control circuit closes each flow control valve when the temperature at the inlet end of its associated evaporator coil reaches or exceeds a preset value to ensure that no gas refrigerant passes from its associated evaporator coil to other elements of the refrigeration system during the defrost cycle.

Abstract: When a defrosting requiring signal is outputted, the opening of a motor-operated expansion valve (5) is fully closed in a heating cycle so that refrigerant is recovered into a receiver (4). In addition, when the defrosting requiring signal is outputted, an indoor fan (6f) is deactivated so that heat is stored. Further, when the completion of the recovery of refrigerant is determined, defrosting operation is executed. The recovery of refrigerant is completed when an outdoor heat-exchange temperature Tc at the present time drops to or below a specified temperature, when the outdoor heat-exchange temperature Tc at the present time drops to or more than a specified difference from a reference outdoor heat-exchange temperature Tcl at the time before the motor-operated expansion valve (5) is fully closed, when an indoor heat-exchange temperature Te at the present time rises to or above a specified temperature, or when a set time passes.

Abstract: A refrigeration system includes a compressor, a condenser, an expansion throttle, an evaporator and a control valve. All of the above elements are connected in series, in that order, in a refrigerant flow relationship. During periods in which the compressor initiates a passive defrost mode, control valve disposed within the conduit connecting the compressor and the evaporator remains open. Liquid refrigerant, by force of gravity, drains from the bottom of evaporator through the conduit to the compressor. This draining liquid refrigerant is evaporated by the hot compressor, flowing upward to the cold evaporator surfaces and condensing. The condensation releases latent heat of vaporization and heats the surface of the evaporator melting ice buildup thereon. In another embodiment, the refrigeration system further includes a bypass line connecting the compressor to the top of the evaporator.

Abstract: The invention prevents the temperature of supplied air from being decreased by a defrosting operation when a vehicle is in operation. During the heating operation, it is judged whether the vehicle is in operation. When the vehicle is in operation, it is judged whether an external heat exchanger is frosted or not relying upon the external air temperature, temperature of the external heat exchanger (coolant) and the time of heating operation. When it is judged that frost is formed, the rotational speed of the compressor is increased to increase the ability to supplying the coolant, to maintain heating ability and to prevent the drop of temperature of the supplied air. When the frost is formed after the operation of the vehicle has been finished, it is judged whether the secondary batteries are being charged or not, i.e., whether the charging circuit of the secondary batteries is connected to the external power source for charging or not.

Abstract: A receiver (4) is provided in a main line (9a) and a bypass passage (4a) having an open/shut-off valve (SV) is provided for introducing gas refrigerant in the receiver (4) into a low-pressure liquid line. A motor-operated expansion valve (5) is fully closed, the open/shut-off valve (SV) is opened, and then defrosting operation is executed. At the initial stage of the defrosting operation, the open/shut-off valve (SV) is closed. When a discharge-pipe temperature Td drops to or below a specified temperature, the open/shut-off valve (SV) is closed. When the discharge-pipe temperature Td rises to or above a specified temperature, the motor-operated expansion valve (5) is once opened to a specified opening. When defrosting operation is completed, the open/shut-off valve (SV) is opened in a heating cycle and the motor-operated expansion valve (5) is gradually opened.

Abstract: A refrigeration cycle including a compressor, an indoor heat exchanger, an expansion, an outdoor heat exchanger and a six-way change-over valve having a refrigerant passage through which refrigerant flows in a refrigerant circuit comprising the compressor, the indoor heat exchanger, the expansion and the outdoor heat exchanger, wherein the six-way change-over valve serves to selectively switch the refrigerant passage so that the refrigerant passing in the indoor and outdoor heat exchangers flows in the same direction at any time when the refrigerant cycle is switched to a cooling operation cycle and to a heating operation cycle.

Abstract: Disclosed is a refrigerant circuit for ice making machines and the like, the circuit comprising a freezing circuit in which a high-pressure and high-temperature vaporized refrigerant is fed from a compressor through a solenoid valve to a condenser, the refrigerant liquefied in the condenser is then fed to an expansion means, the refrigerant vaporized through the expansion means is further fed to an evaporator, and the vaporized refrigerant heated through heat exchange is fed back to the compressor; and a hot gas circuit which bypasses the high-pressure and high-temperature vaporized refrigerant fed from the compressor to the evaporator through a hot gas valve so as to achieve ice releasing and the like at the evaporator; the solenoid valve and the hot gas valve being designed to be let open and closed, respectively, during the freezing operation, and to be closed and let open, respectively, when the operation mode is switched to the ice releasing operation; wherein a pressure detecting means is interposed bet

Abstract: A hot gas defrost system for a refrigeration cycle, including at least one compressor, condenser, receiver, expansion valve and evaporator. During defrost, a pressure-sensitive valve to the condenser inlet is normally closed, and the flow of refrigerant from the compressor bypasses the condenser and flows to the receiver. However, when the pressure in the system reaches a critical point, the pressure-sensitive condenser inlet valve will open to release the excessive pressure. The condenser inlet valve is also temperature-sensitive and will open if the ambient temperature surrounding the condenser is above a specific point. Opening of the condenser valve permits the utilization of the hot gas in the condenser for defrost and to decrease the thermal shock resulting from the superheated vapor contacting the evaporator coil. The compressor, which needs a constant flow of liquid refrigerant for cooling, is continually supplied with liquid refrigerant.

Abstract: An air conditioning system suitable for use in an electric vehicle. In the air conditioning system, a refrigerant gas circulatory system of the heat pump type for selectively effecting cooling and heating is disposed inside the electric vehicle and comprises lines which interconnect three heat exchangers, a directional control valve, a compressor and an expansion valve to one another. A control device is provided so as to activate and inactivate the heat exchanger, the directional control valve and the compressor. Before the expected running of the vehicle, at least a portion of the refrigerant gas circulatory system can be operated by the control device using a drive source different from the drive source used for running the vehicle. Accordingly, a comfortable room environment can be established for the expected time on riding by activating the air conditioning system in an unmanned state.

Abstract: Disclosed is a refrigerant circuit for an ice making machine and the like, in which not only drop in the performance or damage of a compressor due to the abnormally elevated higher level pressure thereof but also double-freezing can effectively be prevented.

Abstract: A freezer system is disclosed comprising a freezing mechanism and an adjacent freezer cabinet. The freezer mechanism has a compressor that produces hot gas refrigerant, a condenser, and an evaporator which accumulates ice on its outside surface. An evaporator condensate pan is mounted beneath the evaporator and a compressor condensate pan is mounted beneath the compressor and connected by a conduit to the evaporator condensate pan. A condensate pan heater coil is attached to the bottom of the evaporator condensate pan. A hot gas valve connected between the compressor and the condensate pan heater coil, when activated, conducts hot gas refrigerant to the condensate pan heater coil to heat it and thereby heat the attached evaporator condensate pan, which in turn heats the outside of the evaporator to help melt accumulated ice. The hot gas refrigerant is then fed from the condensate pan heater coil to the evaporator, heating the inside of the evaporator and fully melting the ice.

Abstract: A system for controlling operation of a refrigerating device which includes a refrigerant circuit (9) in which a compressor (1), a condenser (6), a receiver (4) for storing liquid refrigerant, a pressure-reducing valve (5), and an evaporator (9) are connected together, and a cycle changeover mechanism (2) for changing a refrigeration cycle of the refrigerant circuit (9) between forward operation and reverse operation, the refrigerating device being of such arrangement that the pressure-reducing valve (5) is positioned downstream of the receiver (4) during either one of the refrigerating cycles. The system prevents liquid back-flow to the compressor at the time of a cycle changeover, while allowing the refrigerating device to have accumulatorless construction. The top portion of the receiver (4) is connected to a liquid line on the downstream side of the pressure-reducing valve (5) through a bypass path (4a), and an on-off valve (SV) is provided in this bypass path (4a).

Abstract: An automated processing freezer system is described that provides a plurality of cooling units to chill the air within a freezing enclosure, whereby the coils of each cooling unit may be defrosted independently, without louvers or other moving mechanisms, while the cooling output of the freezer system is maintained 24 hours a day. Baffles in the freezing enclosure isolate each cooling unit from the airflow associated with the other cooling units, thereby eliminating the need for expensive and less efficient louvers surrounding the coils of each cooling unit.

Abstract: A refrigeration system includes a temperature sensor in a freezing compartment, a temperature sensor in a cooling compartment, an adjustable damper controlling the flow of cooled air from the freezing compartment to the cooling compartment and variable speed drives for fan motors and a compressor motor. The desired set point temperatures for the compartment are compared with the actual sensed temperatures through a controller that controls the speed of the compressor and fan motors, to achieve the desired temperature in a fast and efficient manner. When excessive ice is detected on freezing compartment coils, the controller reverses the heat transfer cycle of the refrigerant to defrost the freezing compartment coils.

Abstract: A refrigeration system for providing cooling to two or more compartments utilizing respective first and second evaporators. During the initial operation of a cooling cycle, the refrigerant is utilized for cooling the compartment (such as a fresh food compartment) which is to be maintained at a higher temperature as compared with another compartment (such as a freezer compartment). Cooling can thus be achieved by operating a fan in the fresh food compartment, even where the refrigeration system has not yet reached steady state after the compressor initially begins operating. After cooling has been achieved in the fresh food compartment, the refrigerant in the system has reached a state suitable for cooling of the freezer compartment, and the fan for the freezer evaporator is turned on while the fan for the fresh food compartment is turned off.

Abstract: A heat storage type air conditioner which is free from a difficulty that, when a general cooling and heating circuit and a cold radiating and heat radiating circuit are operated separately or simultaneously, the quantities of refrigerant in those circuits become smaller or larger than required, so that its compressor is damaged or the cooling or heating capacity is lowered. When, in a heat storage type air conditioner, first and second bypass circuits 22 and 23 are closed, a general cooling and heating circuit 18 driven by a compressor 1 and a cold radiating and heat radiating circuit 21 driven by a refrigerant gas pump 13 are made independent of each other, so that a cooling operation or a heating operation is carried out with the aid of a first use-side heat exchanger 4a and a second use-side heat exchanger 4b. Therefore, in the air conditioner, the refrigerant or refrigerating machine oil will never concentrate in any one of the two circuits.

Abstract: A method of eliminating odor in a heat pump system of a vehicle includes the steps of detecting removal of the vehicle passengers and ignition key after use of the cooling mode or air conditioning of the passenger compartment heat exchanger, operating the blower, reversing the flow of refrigerant in the heat pump to place the passenger compartment heat exchanger in heating mode to remove latent moisture to eliminate odor therefrom.

Abstract: The present invention aims at providing a refrigerating system capable of cooling a compressor stably using a liquid injection circuit even when defrosting of an evaporator is performed using a gaseous refrigerant of high pressure. The refrigerating system comprises a compressor having a refrigerant discharge side and a refrigerant suction side; a condenser connected to the discharge side of the compressor; a receiver tank connected to a refrigerant outlet side of the condenser; an evaporator connected between a refrigerant outlet side of the receiver tank and the suction side of the compressor; a defrosting circuit which supplies a gaseous refrigerant obtained by gas-liquid separation in the receiver tank to the evaporator to defrost the evaporator; and a liquid injection circuit which supplies a liquid refrigerant obtained by gas-liquid separation in the receiver tank to a low pressure side in the interior of the compressor.

Abstract: Disclosed is a cooling medium circuit for ice making machines and the like, comprising a freezing circuit in which a high-pressure and high-temperature vaporized cooling medium compressed in a compressor is fed to a condenser, the cooling medium liquefied through condensation in the condenser is fed to an expansion means through a first solenoid valve, the cooling medium expanded and vaporized through the expansion means is fed to an evaporator to perform heat exchange and the thus heated vaporized cooling medium is fed back to the compressor; and a hot gas circuit in which the high-pressure and high-temperature vaporized cooling medium fed from the compressor is partly by-passed to the evaporator through a second solenoid valve and a choking means to achieve ice releasing and the like in the evaporator, wherein the state of the first solenoid valve and that of the second solenoid valve can be changed over synchronously each time the ice making machine is switched to freezing operation or to ice releasing ope

Abstract: A gas defrost apparatus for melting frost and ice from evaporators in commercial refrigeration systems using a pressure differential hold back valve to direct superheated refrigerant in a reversed direction into the evaporators and a gas return conduit for reintroducing the refrigerant into the main refrigerant distribution system between the compressors and condensers. Reintroducing the refrigerant on the high side of the condensers between the compressors and condensers prevents inefficiencies in the refrigeration system.

Abstract: Method and apparatus to defrost evaporator coils of a refrigeration system by periodically replacing the refrigerant in the evaporator coils by hot refrigerant gas from the compression side of a compressor. The gas from the compressor is sent through an oil separator, then through a solenoid valve to a vaporizer tank. From the vaporizer tank, a portion of the hot gas is fed constantly during the defrosting cycle through a metering flow control valve to the evaporator coils. As the pressure builds up in the vaporizer tank due to the compressor supplying more gas than the amount flowing through the metering flow control valve, a pressure control senses the pressure increase and opens a vaporizer solenoid valve to allow additional hot gas to flow to the evaporator coils. In the evaporator the gas heats the evaporator coils and melts the frost on the coils and then passes to the suction line of the compressor.

Abstract: An air conditioning system in which a single heat source unit (A) comprising a compressor (1), a four-way valve (2), a heat source unit side heat exchanger (3) and an accumulator (4) is connected to a plurality of indoor units (B, C, D) through a first and a second connection pipes (6, 7). Each indoor unit (B, C, D) comprises a suction air temperature detecting device (50) for detecting a suction air temperature of the indoor unit, an opening degree setting device for setting a minimum valve opening degree of the first flow rate controller 9 in accordance with the difference between the target temperature and the suction air temperature and a first valve opening degree control device (52) for controlling the valve opening degree of the first flow rate controller 9 at a predetermined rate to the minimum valve opening degree. A bypass system is further provided to enable an effective defrost operation.

Abstract: An air conditioning system includes: a compressor, an outside air heat exchanger, an outside air heat exchanger fan, an expansion valve, an interior heat exchanger, an interior heat exchanger fan, and a four-way switching valve further comprises an outside air induction/venting device provided outside the outside air heat exchanger. A device for switching or opening/closing the air intakes and/or outlet of the outside air heat exchanger are provided in the outside air induction/venting device and are operated to enable the efficient use of waste heat from the drive shaft motor or inside the passenger compartment, and to provide a defrost cycle in the heat pump heating mode.

Abstract: During the heating cycle of an air conditioning system, a portion of the compressed refrigerant is conducted between outdoor and indoor heat exchangers for heating a dwelling, and another portion of the compressed refrigerant is conducted to an auxiliary condenser. Heat from the auxiliary condenser is directed against the outdoor heat exchanger to defrost the latter.

Abstract: A passive defrost system uses a heat-exchanger/storage defrost module containing a thermal storage material such as a phase change material to capture and store low grade, waste heat contained in the liquid refrigerant line of a refrigeration system. The waste heat is stored during normal operation. Upon shut down of the refrigeration system, the stored heat in the defrost module is released by an automatic device for defrosting the evaporator. The preferred embodiment of this passive defrost system includes the defrost module and some device to transfer heat from the defrost module to the evaporator, preferably in the configuration of a gravity heat pipe. Since waste heat is taken out of the liquid refrigerant line, the efficiency of the refrigeration system is improved, and no additional energy is needed for the defrost operation.

Abstract: A refrigeration and defrost system utilizing various valves for opening a defrost line to hot gas and regulating the pressure in refrigerant lines. A slug surge suppressor is provided at several points in the defrost and refrigerant lines to alleviate hydraulic shock damage caused by liquid/gas "slugs" passing rapidly through the lines. The slugs are commonly formed by the required rapid opening of the various valve of the system. Capillary passages in the suppressor resist liquid flow while allowing gas to flow freely.

Abstract: Methods and apparatus for eliminating the need for a float valve in a flash tank of a refrigeration system having an economizer cycle, improving stationary refrigeration systems and permitting a flash tank instead of a heat exchanger to be used in a transport refrigeration system having an economizer cycle. The refrigeration system includes a refrigerant compressor, a condenser, and an evaporator, with the flash tank being disposed between the condenser and evaporator. A liquid sub-cooling valve is disposed between the condenser and flash tank. The liquid sub-cooling valve opens and closes to maintain a desired degree of sub-cooling, with the liquid sub-cooling valve thus controlling refrigerant flow into the flash tank. Refrigerant flow out of the flash tank to the evaporator is controlled by a suction superheat thermostatic expansion valve. In a preferred embodiment, liquid leaving the flash tank is sub-cooled before entering the expansion valve.

Abstract: An economizer arrangement for ice making reverse cycle refrigeration system of the type employing hot-gas defrosting, including a condenser, a receiver to receive liquid refrigerant, a plural tube evaporator having an internal refrigerant chamber in each tube and an expansion valve through which the refrigerant flows into the evaporator tubes during a freezing cycle of the system to cause ice formation on ice-making surfaces of the evaporator means in heat exchange relation with the refrigerant chamber. A rotary screw type compressor supplying to the condenser and has an economizer port at a location along the screw where the pressure builds up to a selected level, a refrigerant valve passes the condenser and routes hot-gas refrigerant during a harvest defrost cycle to the evaporator tubes, and a relief conduit tube communicates the refrigerant chambers of the evaporator tubes with the economizer port.

Abstract: A method for controlling a refrigerant path apparatus including a pressurized gas refrigerant path for a flow of a pressurized gas refrigerant which has not been substantially cooled to be liquefied, a pressurized liquid refrigerant path for a flow of a pressurized liquid refrigerant which is generated from the pressurized gas refrigerant by being cooled to be liquefied, a first heat exchanger means which is fluidly connected to the pressurized gas refrigerant path to supply the pressurized gas refrigerant into the first heat exchanger so that a heat exchange is carried out between the pressurized gas refrigerant in the first heat exchanger and the outside of the first heat exchanger, comprises the steps of allowing a flow of the refrigerant from the pressurized gas refrigerant path to the pressurized liquid refrigerant path when a supply of the pressurized gas refrigerant from the pressurized gas refrigerant path into the first heat exchanger means is prevented, and preventing the flow of the refrigerant fro

Abstract: This invention provides a full flow vaporizer for use in a refrigeration system (which may be part of a heat pump) employing hot gas from the compressor to periodically defrost the cooling coil or coils. The vaporizer usually consists of three concentric circular cross-section tubes, the innermost tube receiving the fluid from the coil and being divided about midway along its length by a disc transverse barrier into first and third chambers. The cylindrical wall of the first chamber is provided with a plurality of holes directing the fluid forcefully radially outwards into a second chamber between the innermost and middle tubes and against the inner wall of the middle tube, which is heated by hot refrigerant gas passing in a fourth chamber between the middle and outermost tubes, the fluid then passing from the second chamber into the third chamber through a similar plurality of holes in the innermost tube cylindrical wall.

Abstract: A transport refrigeration system of the type which holds a set point by operating in heating and cooling cycles. The system includes a compressor, a condenser and an evaporator each having inlet and outlet ports. A three-way valve receives compressed gas discharged from the compressor and directs it selectively to first and second outlets. First outlet of the three-way valve directs hot compressor gas to the condenser for operation of the system in a conventional cooling cycle. A hot gas conduit is provided which connects the second outlet of the three-way valve directly to the inlet of the evaporator. A branch line extends from the hot gas line to the line interconnecting the condenser and the evaporator, upstream of the receiver. Another refrigerant line extends from the outlet of the condenser to establish fluid communication with the line interconnecting the outlet of the evaporator with the compressor suction port.

Abstract: In multiple system type air conditioner, there are provided an auxiliary outdoor heat exchanger provided in an outdoor unit, and defrosting device that, on heating operation, periodically or as needed feeds the refrigerant discharged from the compressor to the outdoor heat exchanger and all the indoor heat exchangers. After the refrigerant has passed through the outdoor heat exchanger and all the indoor heat exchangers, the refrigerant returns to the compressors through the auxiliary outdoor heat exchanger.

Abstract: A heat pump or the like with a heating, cooling and defrost cycle, the heat pump including an auxiliary heat exchanger that includes a first coil and second coils, the auxiliary heat exchanger operatively connected to a primary refrigerant flow circuit such that hot gaseous refrigerant from the compressor flows through the first coil. The heat pump also includes a bypass refrigerant conduit for bypassing the indoor heat exchanger during the defrost cycle, the bypass conduit connecting the primary circuit to the second coils of the auxiliary heat exchanger so that the second coils act as an evaporator in the defrost cycle. Hot gaseous refrigerant directed through the first coil of the auxiliary heat exchanger warms second coils so that refrigerant directed into the second coils is more efficiently evaporated.

Abstract: A heat pump is provided with a reversible fan motor in its outdoor coil and, after a delay period following initiation of the defrost cycle, the fan is caused to operate in a reverse direction to thereby cause the surrounding air to flow through the outdoor coil in a direction opposite to that in which it flows during the heating mode operation. During this time, the fan is operated at a relative slow speed to thereby prevent the convective flow of heat upwardly, while at the same time causing little, if any, flow of ambient air downwardly into the coil.

Abstract: An air conditioning system including a refrigerant circuit having a compressor, a three port switching valve, a four port reversing valve, an outdoor heat exchanger, a first throttle device including a first decompression device, a second throttle device including a first decompression device, an indoor heat exchanger and an accumulator connected in series by use of refrigerant pipes; a first bypass circuit which is constructed to carry out heat exchange with the intake pipe connecting between the accumulator and the compressor, and which is connected as a bypass to the pipe connecting between the first and second throttle devices; a second bypass circuit having a check valve to bypass the first decompression device; a third bypass circuit having a check valve to bypass the second decompression device; a fourth bypass circuit which is connected as a bypass to the pipe between the first and second throttle devices, and which is smaller than the discharge pipe in inside diameter; and a fifth bypass circuit whic

Abstract: A refrigeration system utilizing hot gas for defrost and a hot gas defrost valve with specific opening characteristics for rapidly reducing the pressure gradient across the valve without producing hydraulic shock. When defrost is called for by the system, the hot gas defrost valve is opened in a manner which prevents a liquid or liquid-gas slug from impacting on cold system components and producing liquid hammer effect damage.

Abstract: A refrigeration and defrost system utilizing various valves for opening a defrost line to hot gas and regulating the pressure in refrigerant lines. A slug surge suppressor is provided at several points in the defrost and refrigerant lines to eliminate hydraulic shock damage caused by slugs of a liquid-gas mixture passing rapidly through the lines. The slugs are generally formed by the required rapid opening of a hot gas defrost valve and a pressure regulatory valve of the system. A series of capillary passages in the suppressor are operative to resist the flow of liquid while allowing gas to flow freely. Tangential velocity is imparted to the slug to separate the liquid and gas components of the slug.

Abstract: A hot gas defrost refrigeration system has a compressor, a condenser, a receiver, an evaporator, interconnected by fluid passage means and incorporating valve means to cause refrigerant to flow sequentially through the compressor, condenser, receiver and evaporator to the compressor during the refrigeration cycle. The refrigeration system includes a superheater and defrost passage means, including valve means, connecting the evaporator outlet to the condenser inlet and connecting the condenser outlet through the superheater to the compressor inlet, bypassing the receiver. The passage means connecting the compressor outlet with the evaporator inlet includes a superheat passage in heat exchange relationship with the superheater for transferring heat from the refrigerant discharged from the compressor outlet to the refrigerant delivered to the compressor inlet during the defrost cycle.

Abstract: A method and apparatus for defrosting the outside heat exchanger of a reversible vapor compression refrigeration (heat pump) system. The method and apparatus are particularly suited for use with smaller systems that employ a single fan motor to drive both the inside and outside heat exchanger fans. A heat storage apparatus is mounted in heat exchange relationship with the refrigerant piping between the system flow reversing valve and the inside heat exchanger. During operation in the heating mode, heat from the refrigerant is transferred to and stored in the heat storage apparatus. During operation in the defrosting mode, the refrigerant flow in the system is aligned as in the cooling mode but both fans are shut off. Heat stored in the heat storage apparatus is transferred to and used for defrosting the outside heat exchanger. The apparatus has little or no effect on system operation in the cooling mode.