Abstract: In order to improve a refrigeration system comprising a refrigeration circuit, in which a refrigerant compressor, a condenser following on from the refrigerant compressor, an expansion device following on from the condenser and an evaporator following on from the expansion device are arranged, the evaporator being connected to the refrigerant compressor, wherein the refrigerant compressor has a drive motor speed-controlled by an electronic motor control and a control cooling branch which has refrigerant flowing through it, branches off from the refrigeration circuit between the condenser and the expansion device and is guided to a connection of the refrigerant compressor and in which a cooling element is arranged which is connected in a heat conducting manner to electronic power components of the motor control, in such a manner that disruption to the operation of the motor control is avoided as far as possible it is suggested that a regulating device be provided for the control cooling branch and this regulat

Abstract: An air-conditioning apparatus includes a refrigerant circuit including a low-pressure shell structure compressor into which a refrigerant flowing through an injection pipe flows, a first heat exchanger, a second heat exchanger, a first expansion device, a refrigerant flow switching device, and a second expansion device configured to allow the refrigerant which has passed through the first expansion device and flows from the second heat exchanger to the first heat exchanger to have an intermediate pressure, the compressor, the first heat exchanger, the second heat exchanger, the first expansion device, the refrigerant flow switching device, and the second expansion device being connected by pipes to constitute the refrigerant circuit, and further includes a controller that controls an amount of refrigerant flowing through the injection pipe into a compression chamber. A part of a high-pressure refrigerant flowing from the first heat exchanger to the second heat exchanger flows through the injection pipe.

Abstract: In a temperature control system using a controlled mix of high temperature pressurized gas and a cooled vapor/liquid flow of the same medium to cool a thermal load to a target temperature in a high energy environment, particular advantages are obtained in precision and efficiency by passing at least a substantial percentage of the cooled vapor/liquid flow through the thermal load directly, and thereafter mixing the output with a portion of the pressurized gas flow. This “post load mixing” approach increases the thermal transfer coefficient, improves control and facilities target temperature change. Ad added mixing between the cooled expanded flow and a lesser flow of pressurized gas also is used prior to the input to the thermal load. A further feature, termed a remote “Line Box”, enables transport of the separate flows of the two phase medium through a substantial spacing from pressurizing and condensing units without undesired liquefaction in the transport lines.

Abstract: To obtain a multiple-unit air conditioning apparatus capable of detecting, when improper wire connections are made, improper wiring and eliminating an improper wiring state without performing a re-wiring work. When an operation command for an indoor unit Y, received from indoor unit control means 15, does not match a refrigerant circuit of an indoor unit Y whose refrigerant circulation is controlled by outdoor unit control means 14, operation patterns are extracted on the basis of the number of operating indoor units Y. A refrigerant circuit in which a refrigerant is circulated is switched in accordance with the operation patterns. Each wire 18 connected to the indoor unit control means 15 of each indoor unit Y is associated with each refrigerant circuit controlled by the outdoor unit control means 14, and recognition of wire connections is changed.

Abstract: For cooling operation, a refrigeration apparatus includes a heat-source-side valve opening controller for controlling a degree of opening of a heat-source-side expansion valve so that pressure of a refrigerant flowing into the utilization-side expansion valve in the cooling operation becomes equal to or lower than a predetermined reference pressure value. For heating operation, the refrigeration apparatus includes a utilization-side valve opening controller for performing, when a low-quantity utilization unit in which a quantity of the refrigerant falls below a quantity of the refrigerant required for delivering capacity of the utilization unit is found among a plurality of the utilization units in the heating operation, valve opening reducing operation of reducing a degree of opening of the utilization-side expansion valve of the utilization unit except for the low-quantity utilization unit.

Abstract: A vapor compression refrigeration cycle system includes a compressor and an electronic expansion valve connected between first and second refrigerant ports of a compressor. An expansion valve controller is configured to control a flow of refrigerant through the expansion valve in response to a superheat temperature of the refrigerant. The controller is configured to execute a first control algorithm until a local maximum of the superheat temperature occurs, and then to execute a second control algorithm.

Abstract: A refrigeration system for a frozen product dispenser is controlled to have a variable cooling capacity that is determined by variable cooling load demands of the dispenser. This is accomplished, in part, by providing the refrigeration system with a variable speed compressor and one or more adjustable expansion valves for metering refrigerant to associated evaporators that are heat exchange coupled to associated freeze barrels of the dispenser, and by controlling the metering setting of the expansion valves and the speed of operation of the compressor in accordance with the cooling load demands of the dispenser. The arrangement provides for efficient operation of the refrigeration system from an energy standpoint and for a reduction in on/off cycling of the system.

Abstract: A refrigerant vapor compression system includes a flash tank receiver disposed in the refrigerant circuit intermediate the refrigerant cooling heat exchanger and the refrigerant heating heat exchanger. The flash tank receiver, which receives a liquid/vapor refrigerant mix, also functions as a receiver. A refrigerant charge control apparatus includes at least one sensor for sensing an operating characteristic of the refrigerant circulating through the refrigerant compression device, and a controller operative to selectively adjust a secondary expansion device to increase or decrease the flow of refrigerant passing into the flash tank receiver to provide a circulating refrigerant charge consistent with maintaining a desired system operating characteristic.

Abstract: An air conditioning apparatus (10) includes a heat source unit (20), usage units (40, 50, 60), and a controller (80). The heat source unit (20) has a compression mechanism (21), a heat-source-side heat exchanger (23) functioning at least as an evaporator, and a heat-source-side expansion valve (38). The usage units (40, 50, 60) have usage-side heat exchangers (42, 52, 62) functioning at least as condensers, and usage-side expansion valves (41, 51, 61). The controller (80) regulates the opening degree of the heat-source-side expansion valve (38) on the basis of the opening degrees of the usage-side expansion valves (41, 51, 61).

Abstract: A system supplies a fluid to an evaporator of a refrigeration unit and has first and second lines connected to a fluid inlet of the evaporator. The system has an expansion valve with a continuously modifiable first flow cross section, disposed in the first line, the continuously modifiable first flow cross section setting a first mass flow through the first line. A shut-off device is disposed in the second line and switchable discretely between an open position and a closed position. A throttle with a constant second flow cross section is disposed in the second line. A control unit continuously modifies the first flow cross section of the expansion valve and controls the shut-off device as a function of the first flow cross section.

Abstract: A cooling system has a tandem compressor, a condenser, an electronic expansion valve and an evaporator arranged in a direct expansion cooling circuit. The tandem compressor includes a variable capacity compressor and a fixed capacity compressor. A controller controls the electronic expansion valve and selects which of a plurality of superheat control modes to use in operating the electronic expansion valve based on control parameters and a current operating status of each of the variable capacity compressor and fixed capacity compressor of the tandem compressor.

Abstract: A cooling system has a cabinet and a plurality of separate cooling stages including an upstream cooling stage and a downstream cooling stage. At least the upstream cooling state is a variable capacity cooling stage. Each cooling stage has a cooling circuit. Evaporators of the cooling circuits are arranged in the cabinet so that air passes over them in serial fashion. A controller when a Call for Cooling first reaches a point where cooling is needed, operating the upstream cooling circuit to provide cooling and not the downstream cooling circuit. When the Call for Cooling has increased to a second point, the controller additionally operates the downstream cooling circuit to provide cooling. The cooling capacity at which the upstream cooling circuit is being operated is less than its full capacity when the Call for Cooling reaches the second point.

Abstract: A compressor includes a casing accommodating a refrigerant passageway, a compression mechanism and a pipe. The compression mechanism is disposed in the interior of the casing to discharge compressed refrigerant into the refrigerant passageway. The pipe extends from inside of the casing to outside of the casing. The pipe includes two ends. One end is a closed end disposed in a predetermined position inside the refrigerant passageway. The other end of the pipe is an opened end disposed outside the casing. The pipe is preferably sized so that a measuring instrument can be inserted into the pipe through the opened end.

Abstract: A refrigeration system includes a refrigerant circuit performing a vapor compression supercritical refrigeration cycle. The system includes a compression mechanism, a heat source heat exchanger, an expander, and a utilization heat exchanger. The expander includes, for two-stage compression, a high pressure side and a low pressure side throttle mechanism, both variable in the amount of throttling. A controller is configured to derive a target value, providing a maximum COP, for the pressure of high pressure refrigerant in the refrigerant circuit based on the temperature of refrigerant at the outlet of either the heat source side heat exchanger or the utilization side heat exchanger, whichever becomes a heat dissipation side heat exchanger functioning as a heat dissipation unit and on the temperature of a medium exchanging heat with refrigerant in the heat dissipation side heat exchanger, at the inlet of the heat dissipation side heat exchanger.

Abstract: A refrigeration system for a frozen product dispenser is controlled to have a variable cooling capacity that is determined by variable cooling load demands of the dispenser. This is accomplished, in part, by providing the refrigeration system with a variable speed compressor and one or more adjustable expansion valves for metering refrigerant to associated evaporators that are heat exchange coupled to associated freeze barrels of the dispenser, and by controlling the metering setting of the expansion valves and the speed of operation of the compressor in accordance with the cooling load demands of the dispenser. The arrangement provides for efficient operation of the refrigeration system from an energy standpoint and for a reduction in on/off cycling of the system.

Abstract: A refrigeration system is provided with an ice maker chamber within a fresh food compartment. The refrigeration system includes a refrigeration path and an ice maker path. The ice maker path includes an electronic expansion valve for controlling the refrigerant entering an ice maker evaporator and an evaporator pressure regulator. Controlling the refrigeration system includes the steps of sensing a first refrigerant temperature at an exit of the ice maker evaporator and controlling a first control of the electronic expansion valve until the temperature reaches a temperature target. The method of controlling can further include comparing a slope of the temperature to at least one of a minimum, a target, or a maximum setting to adjust the control. Subsequently, a second control for the electronic expansion valve can be repeatedly adjusted by evaluating the first refrigerant temperature and the slope.

Abstract: A system for improving the thermal efficiency of a thermal control loop in which refrigerant after compression and condensation is applied to an evaporator employs a subsidiary counter-current heat exchange intercepting refrigerant flow to maintain the quality of the refrigerant by exchanging thermal energy between the input flow and the output flow from the evaporator. The same principle is effective, with particular advantage when small connections have to be made, in systems using mixed phase media and using the concept of direct energy transfer with saturated fluid.

Abstract: The invention includes a refrigerant circuit for a cooling operation and a heat pump operation. The refrigerant circuit has a high pressure area and a low pressure area, including at least one heat source/heat sink, a compressor, an expansion device, at least one thermal interior space module, and an internal heat exchanger. The internal heat exchanger has a high pressure side part and a low pressure side part, wherein the high pressure side part is disposed between the expansion device and the heat source/heat sink. The invention also includes at least one metering device through which the high pressure side part of the internal heat exchanger is operable during the heat pump operation at a medium pressure level intermediate a pressure level in the high pressure area and a pressure level in the low pressure area of the refrigerant circuit.

Abstract: Provided is an air-conditioning and hot water supply combination system capable of maintaining a high hot water supply capacity and achieving high efficiency even under high-temperature outside air conditions by appropriately controlling the degree of superheat and the degree of subcooling of a heat exchanger. In an air-conditioning and hot water supply combination system, when an evaporating pressure or an evaporating temperature calculated from the evaporating pressure reaches a first predetermined value or higher, the degree of superheat of a refrigerant on a low-pressure gas side of a subcooling heat exchanger or the degree of subcooling of the refrigerant on a high-pressure liquid side of the subcooling heat exchanger is controlled by the opening degree of a low-pressure bypass pressure reducing mechanism, such that the evaporating pressure or the evaporating temperature calculated from the evaporating pressure is less than or equal to the first predetermined value.

Abstract: In a refrigerating cycle apparatus and control method thereof, a controller sets a high-pressure pressure target value from thermal load and temperature conditions based on refrigerant information that has been obtained from detectors, and controls at least one of a rotational frequency of a compressor, a degree of opening of an electronic expansion valve, a rotational frequency of an outdoor fan, or a rotational frequency of an indoor fan to match a high-pressure pressure to the high-pressure pressure target value that has been set. Here, a threshold value is set when the high-pressure pressure target value is set, and a method for setting the high-pressure pressure target value is modified depending on whether the high-pressure pressure is greater than or equal to the threshold value or less than the threshold value when the high-pressure pressure target value is decided.

Abstract: Human detection devices 8 that detect the number of people in conditioned spaces supplied with conditioned air from the use side heat exchangers 12 and control means 9 and 50 that controls an amount of refrigerant supplied to the use side heat exchangers 12 by controlling opening degrees of the expansion devices 5 on the basis of detection results of the human detection devices 8.

Abstract: A refrigeration cycle apparatus increases the cooling capacity even under overload conditions in a refrigeration cycle apparatus that uses a refrigerant which undergoes transition to a supercritical state and in which the high-pressure side enters a supercritical state. A refrigeration cycle apparatus adjusts a high-pressure-side pressure of a refrigerant flowing through a main refrigerant circuit by causing a controller to control an opening degree of a second expansion valve and a heat transfer area of a radiator.

Abstract: A heat pump system includes a refrigerant circuit and a controller. In a heating operation, the usage-side expansion valve is controlled so that a degree of subcooling of outlet refrigerant of the usage-side heat exchanger is equal to a predetermined target degree of subcooling. In a refrigerant recovery control, the heat-source-side expansion valve is controlled so that a degree of superheat of outlet refrigerant of the heat-source-side heat exchanger is equal to a predetermined target degree of superheat, the predetermined target degree of superheat is changed so that the outlet refrigerant of the heat-source-side heat exchanger is wet when the usage-side expansion valve is opened greater than a predetermined opening degree at a start of refrigerant recovery, and change in the predetermined target degree of superheat is cancelled when the usage-side expansion valve is closed smaller than a predetermined opening degree at an end of refrigerant recovery.

Abstract: To provide a temperature sensing tube for an expansion valve in which a hunting can be prevented by slowing of a temperature reaction rate of an expansion valve, a ceramic sintered member serving as a heat transfer delay member (3) in a temperature sensing tube (1) is fixed so as not to directly contact with a tubular member (2) by fixing springs (4, 4) provided at both end portions (13, 13), whereby a heat transfer from the tubular member (2) to the ceramic sintered member becomes slow, temperature is not transferred from a mated piping directly via the tubular member, whichever outer surface of the temperature sensing tube 1 contacts with the piping, and a reaction rate with respect to a temperature rise of the expansion valve can be made slow.

Abstract: A method for controlling a refrigeration system with a variable compressor capacity, and at least two refrigeration entities, e.g. display cases, includes controlling suction pressure by either permitting or preventing the flow of refrigerant into the evaporators of one or more refrigeration entities. The method also includes controlling compressor capacity based on a signal derived from one or more properties of the one or more refrigeration entities, said signal reflecting a possible difference between the current compressor capacity and a current refrigeration demand of the refrigeration system. The method reduces wear on compressors by avoiding switching them ON or OFF to the largest extent possible, and also prevents problems relating to conflicting control strategies due to control parameters, e.g. suction pressure, being determined based on two or more controllable parts, e.g. compressors and flow of refrigerant into refrigeration entities.

Abstract: A system for improving the thermal efficiency of a thermal control loop in which refrigerant after compression and condensation is applied to an evaporator employs a subsidiary counter-current heat exchange intercepting refrigerant flow to maintain the quality of the refrigerant by exchanging thermal energy between the input flow and the output flow from the evaporator. The same principle is effective, with particular advantage when small connections have to be made, in systems using mixed phase media and using the concept of direct energy transfer with saturated fluid.

Abstract: Systems and methods are provided for controlling an expansion valve of a climate control system evaporator coil. An evaporator coil temperature sensor senses temperature of refrigerant within the evaporator coil near the evaporator coil outlet. A controller determines a control set point based on the refrigerant temperature near the evaporator outlet. The control set point is used to determine a valve opening area to regulate refrigerant flow into the evaporator coil such that temperature of refrigerant at the evaporator coil outlet is within a temperature band having a lower bound within a predetermined range above the liquid-to-vapor transition temperature.

Abstract: An air conditioner includes: a compressor for compressing a refrigerant; an expansion valve for adjusting the flow of the refrigerant; a first temperature sensor for detecting a discharge temperature of the compressor; and a second temperature sensor for detecting a temperature of a condenser. A discharge temperature difference is calculated that is a difference between the discharge temperature detected by the first temperature sensor and the temperature of an outdoor heat exchanger or an indoor heat exchanger functioning as the condenser that is detected by the second temperature sensor. The opening of the expansion valve is set based on the calculated discharge temperature difference and a target discharge temperature difference that is set so that a target degree of superheat is obtained.

Abstract: In a refrigeration system having a compressor, a heat rejection heat exchanger, a heat absorption heat exchanger, and a controller for controlling the same, embodiments of a system, apparatus and methods for the same can control at least one refrigeration system component such as an expansion valve responsive to dynamic system conditions.

Abstract: An object of the present invention is to reduce electrical noise in accordance with the necessity of a countermeasure taken against electrical noise without changing a structure of an expansion valve. In a case where a judgment result as to whether or not the countermeasure against electrical noise is taken is affirmative, a drive timing (interval) of an expansion valve (107) is increased. Further, a driving amount is reduced. Accordingly, a flow of a refrigerant is made slow, whereby it is possible to reduce generated electrical noise while performing instructed temperature control.

Abstract: In a thermal control system of the type employing a two phase refrigerant that is first compressed and then is divided into a variable mass flow of refrigerant into a hot pressurized gas form and a differential remainder flow of cooled vapor derived from condensation and then thermal expansion, transitions between different temperature levels are enhanced by incremental variations of the mass flow at different control rates.

Abstract: A HVAC-APU system is provided for a battery electric vehicle. The system includes, but is not limited to a refrigerant fluid. A power cycle loop section, a cabin heating cycle loop section, and a cabin refrigeration cycle loop section are in selective fluid communication with each other to advance the refrigerant fluid through the system. A compressor-expander train includes, but is not limited to a reversing compressor-expander and a high-pressure pump that are operably connected by a shaft. The high-pressure pump pressurizes the refrigerant fluid to form a high-pressure refrigerant fluid. An auxiliary fuel cell and combustion unit heats a heat transfer fluid. A heat exchanger transfers heat from the heated transfer fluid to the high-pressure refrigerant fluid to form a heated high-pressure refrigerant fluid. The reversing compressor-expander expands the heated high-pressure refrigerant fluid to rotate the shaft in a first direction to drive the high-pressure pump.

Abstract: The invention concerns a refrigeration system comprising a refrigerant circuit which comprises several evaporator paths and a distributor (5) which distributes the refrigerant on the evaporator paths. The aim of the invention is to improve the operation of said refrigeration system in a simple manner. According to the invention, the distributor (5) comprises a controllable valve (12) for each evaporation path.

Abstract: A method is provided for protecting a refrigerant vapor compression system during a standstill period following shutdown of the refrigerant vapor compression system. A method is provided for detecting a low refrigerant charge level in a refrigerant vapor compression system operating in a transcritical mode. A refrigerant vapor compression system is provided that includes a controller operative to perform a refrigerant charge detection method.

Abstract: An air conditioner and a method of controlling the same are provided. The air conditioner may include an outdoor unit, one or more indoor units operably coupled to the outdoor unit, a temperature sensor, a valve driver, and a controller. By monitoring an actual temperature and comparing the actual temperature to a desired temperature, a flow path, of flow direction, and flow capacity flowing to the one or more indoor units to adjust a heating/cooling capacity thereof as appropriate.

Abstract: An air conditioner is provided. The air conditioner includes a first temperature sensor configured to measure an indoor temperature during a heating operation, a second temperature sensor configured to measure a discharge temperature of a compressor, a valve provided at an outlet side of an indoor heat exchanger during the heating operation, and a controller configured to control an opening of the valve by comparing a temperature detected by the first temperature sensor with a temperature detected by the second temperature sensor.

Abstract: A refrigeration cycle apparatus 100 includes a compressor 2, a radiator 3, a positive displacement fluid machine 4, an evaporator 7, an injection flow passage 10f and a controller 102. The positive displacement fluid machine 4 performs a step of drawing a refrigerant, a step of expanding and overexpanding the drawn refrigerant, a step of supplying, through an injection port 30, the refrigerant to a working chamber so as to mix the supplied refrigerant with the overexpanded refrigerant, a step of recompressing the mixed refrigerant by using power recovered from the refrigerant, and a step of discharging the recompressed refrigerant. The controller 102 executes an activation control for allowing a pressure in the injection flow passage 10f to be a pressure equal to an outlet pressure of the compressor 2 at time of activation of the refrigeration cycle apparatus 100.

Abstract: A method is provided for controlling an intermittently supercritically operating refrigeration circuit. A control valve (12) is controlled: (a) in the subcritical mode, so that a predetermined “subcritical pressure” ensuring a predetermined sub-cooling of the liquid refrigerant at the outlet (14) of a heat-rejecting heat exchanger (10) is maintained; (b) in the supercritical mode, so that a predetermined “supercritical pressure”, which is optimized for optimum efficiency, of the supercritical refrigerant at the outlet (14) of the heat-rejecting heat exchanger (10) is maintained; and (c) in a border mode in a border region next to the critical point, dependent on a “continuity pressure” which is determined on the basis of the predetermined “subcritical pressure” and the predetermined “supercritical pressure” of steps (a) and (b).

Abstract: A system for reducing the peak power consumption in an electromechanically controlled refrigerator is provided. The system comprises a cold control device including a housing and a counter spring having at least one spring tension position corresponding to a temperature set point, a bourdon tube having a first end comprising an elastomeric diaphragm operatively associated with the counter spring, and a second end, opposite the first end, located in the compartment, wherein the counter spring is capable of providing a force against the diaphragm, and a DSM switching device operatively controlled by an associated DSM module. The DSM module is configured to receive a signal indicative of at least one of a peak or non-peak demand period of an associated utility.

Abstract: A refrigeration device includes a compression mechanism, a radiator, a first expansion mechanism (15), a liquid receiver (16), a second expansion mechanism, an evaporator, a temperature detector, a first pressure storing unit (23a), and a second pressure determining unit, a pressure detector, and a control unit (23c). The first pressure storing unit stores an upper limit and lower limit of an intermediate pressure. The second pressure determining unit determines an upper limit and lower limit of a high pressure based on the upper limit and lower limit of the intermediate pressure and on a temperature in a vicinity of an exit of the radiator. The control unit controls the first expansion mechanism and the second expansion mechanism so that a pressure detected by the pressure detector will be equal to or less than the upper limit and equal to or greater than the lower limit of the high pressure.

Abstract: A first expansion valve is provided in an outdoor unit, and a second expansion valve is provided in an indoor unit. A pipe line connects a first joint pipe of the first expansion valve and a second joint pipe of the second expansion valve. When a refrigerant flows in from the second joint pipe and flows out from the first joint pipe, the first and second expansion valves are in a full open state due to pressure of the refrigerant. When the refrigerant flows in from the first joint pipe and flows out from the second joint pipe, the first and second expansion valves are in semi-closed state (flow rate controlling state). In a cooling mode, the second expansion valve expands the refrigerant just before an indoor heat exchanger, and in a heating mode, the first expansion valve expands the refrigerant just before an outdoor heat exchanger. In both heating and cooling mode, a large amount of refrigerant flows through the pipe line to reduce pressure loss.

Abstract: A first expansion valve is provided in an outdoor unit, and a second expansion valve is provided in an indoor unit. A pipe line connects a first joint pipe of the first expansion valve and a second joint pipe of the second expansion valve. When a refrigerant flows in from the second joint pipe and flows out from the first joint pipe, the first and second expansion valves are in a full open state due to pressure of the refrigerant. When the refrigerant flows in from the first joint pipe and flows out from the second joint pipe, the first and second expansion valves are in semi-closed state (flow rate controlling state). In a cooling mode, the second expansion valve expands the refrigerant just before an indoor heat exchanger, and in a heating mode, the first expansion valve expands the refrigerant just before an outdoor heat exchanger. In both heating and cooling mode, a large amount of refrigerant flows through the pipe line to reduce pressure loss.

Abstract: A vapor compression air conditioning system includes a motor operated expansion valve and control unit including sensors for determining the amount of superheat of the working fluid at or adjacent to the compressor inlet. Expansion valve position is adjusted to maintain a predetermined amount of superheat. The sensors may sense working fluid evaporator temperature and temperature downstream of the evaporator. Dual motor operated expansion valves may be disposed in the working fluid conduit between the heat exchangers in a reversible system. In operation, the expansion valve position may be set as a function of ambient temperature, a previous position, and predetermined superheat requirements to minimize liquid ingestion by the compressor.

Abstract: A modular evaporator which can be assembled from a number of standard modules is provided. Depending on the requirements, the modular evaporator can be assembled to meet a wide range of design cooling loads. Additionally, the modular evaporator is capable of generating and holding ice for thermal storage purposes, eliminating the need for external ice storage tanks. Furthermore, the heat transfer and thermal storage fluid for the evaporator can simply be water which considerably simplifies the system, lowers the cost, and increases the efficiency of the heat transfer loop.

Abstract: An air conditioner controls supply of refrigerant so that the refrigerant is first supplied to one or more indoor units in operation from an outdoor unit, and is then supplied to a hot water generator, thereby sufficiently supplying refrigerant to the indoor units in heating operation even when the hot water generator is operated.

Abstract: An extra low temperature refrigeration system consisting of a two-stage compressor that has an electronic controller. The electronic controller controls an electric expansion valve in the evaporator, which modulates the true superheat. There is also an electric pressure control valve in the condenser, which modulates the head pressure in cool mode, and the suction pressure in defrost mode. The defrost cycle uses a reversing valve. The liquid refrigerant for the inter-stage sub-cooling circuit is constantly provided by a sub-condenser separated from a conventional one condenser system. Therefore, the system provides constant cooling for the compressor motor windings as the compressor runs. There is a one-way pathway from the main condenser circuit to the sub-condenser circuit. This pathway will call for more refrigerant from the main circuit to the sub-cooling circuit as demanded. The inter-stage sub-cooling circuit uses an electric expansion valve true superheat control for its sub-cooler.

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 refrigerating air conditioning system using refrigerant such as CO2 used in a supercritical area, a highly efficient refrigerating air conditioning system is provided by adjusting the amount of refrigerant in a radiator which contributes to the efficiency of the system stably and quickly. During heat utilizing operation, the superheat at the exit of an evaporator is controlled to a predetermined value by controlling the opening of an expansion valve provided on the upstream side of the evaporator, and an expansion valve is controlled so that the state of refrigerant in a connection pipe on the high-pressure side becomes a supercritical state. In this state, a flow rate control valve is controlled to change the density of the refrigerant stored in a refrigerant storage container and the amount of refrigerant existing in the radiator is adjusted.

Abstract: Disclosed is a method and device to efficiently regulate flow of refrigerant while maintaining a sealed chamber in systems providing stored thermal energy for use during peak electrical demand. A mixed-phase regulator replaces the thermostatic expansion valve used in conventional air-conditioning systems that, along with capillary tubes and orifices, regulates the refrigerant fed from the compressor to the heat load.

Abstract: The present invention relates to a refrigerant valve control device and a control method thereof, which adjusts eccentricity of a refrigerant valve during an operation of a refrigerator to prevent overcooling. A refrigerant valve control device of a refrigerator includes a temperature sensing part that senses temperature inside the refrigerator; a refrigerant valve that selectively opens and closes a refrigerant path; and a controlling part that controls the refrigerant valve based on temperature differences between the sensed temperature inside the refrigerator and a predetermined control temperature. In another aspect of the present invention, a control method of a refrigerant valve for a refrigerator includes determining whether refrigerant is leaked at a refrigerant valve based on temperature differences between the temperature inside the refrigerator and a predetermined control temperature; and controlling the refrigerant valve based on the result of the determination.