Abstract: A hole 15 is formed to the center portion of an outer wall 14 of a housing defining an airtight chamber, and temperature sensitive gas is filled in the interior of the housing. The hole 15 is sealed by a plug 16 and is fixed by a weld portion 17. Reference 34 is an anaerobic UV cure adhesive filled in the recess 18 formed around the projection weld portion 17, cured by UV radiation. Portion A showing the surface of the anaerobic UV cure adhesive 34 cures rapidly by UV radiation, and portion B at the inner area of the adhesive where UV cannot be radiated is cured infallibly since portion A becomes anaerobic when cured. Thereby, the periphery of the weld portion 17 is covered with anaerobic UV cure adhesive 34. The thermal expansion valve having such structure can be arranged in an engine room, where corrosion due to water adhering to the weld can be prevented effectively, and as a result prevents gas leak from the weld portion.

Abstract: A control for a refrigeration system serviced by a special pulse width modulated compressor coupled to a condenser and evaporator. The system can be of the distributed type wherein the condenser and compressor may be coupled to service a group of adjacent refrigeration cases, wherein each case would have its own evaporator. A controller is coupled to a load sensor for producing a variable duty cycle control signal in which the duty cycle is a function of demand for cooling. Moreover, fuzzy logic techniques may be utilized in order to provide self adaptive tuning control for the system.

Abstract: A valve body is provided with a valve chamber with a predetermined size having at both ends a fluid inlet and a fluid outlet, a coil spring mounted within the valve chamber of the valve body and expanding and contracting depending upon a variation of fluid temperature with respect to a predetermined value, and a needle inserted into the coil spring for opening and closing fluid passages by moving leftward and rightward within the valve chamber in response to the expansion and contraction of the coil spring.

Abstract: A vapor compression system including a line for flowing heat transfer fluid, a compressor connected with the line for increasing the pressure and temperature of the heat transfer fluid, a condenser connected with the line for liquefying the heat transfer fluid, and an expansion device connected with the line for expanding the heat transfer fluid. The expansion device includes a housing defining a first orifice, and at least one blade connected with the housing, wherein the blade is movable between a first position and a second position, wherein the first orifice is larger in the first position than in the second position. The vapor compression system also includes an evaporator connected with the line for transferring heat from ambient surroundings to the heat transfer fluid.

Abstract: A vapor compression system including a line for flowing heat transfer fluid, a compressor connected with the line for increasing the pressure and temperature of the heat transfer fluid, a condenser connected with the line for liquefying the heat transfer fluid, and an expansion device connected with the line for expanding the heat transfer fluid. The expansion device includes a housing defining a first orifice, and at least one blade connected with the housing, wherein the blade is movable between a first position and a second position, wherein the first orifice is larger in the first position than in the second position. The vapor compression system also includes an evaporator connected with the line for transferring heat from ambient surroundings to the heat transfer fluid.

Abstract: A refrigerant cycle is provided with an expansion device that is movable between a normal mode of operation and a low charge mode of operation. In the low charge mode of operation, the expansion device does not lower the pressure of the refrigerant as much as it does in its normal mode of operation. In this way, the relatively high pressure ratios that are experienced by a compressor during a low charge operation will not be experienced. Instead, the pressure ratio across the compressor is reduced during low charge operation, and the compressor will be better protected.

Abstract: Method for controlling a linear expansion valve in an air conditioner with two compressors, which can prevent breakage of the compressor, and starting failure caused by liquidus refrigerant introduced into the compressor at an initial starting, and preventing drop of cooling performance caused by reduced refrigerant flow coming from a low suction pressure of the compressor at an initial unsteady state.

Abstract: The present invention is directed to a method of reducing cooling capacity in refrigeration systems. The present invention provides a refrigeration system comprising a main, an economizing, and a bypass circuits. The main circuit comprises a compressor, a condenser unit, an expansion device, an evaporator unit, connecting piping and appropriate refrigeration control. The compressor includes an economizer port located in the compression region, and a variable flow valve associated with the economizer port. A body of the valve is a part of a body of the housing and a seat of the valve in a closed position is shaped to be contiguous with internal portion of the housing. The economizer circuit includes a first solenoid valve, an additional expansion device and an economizing heat exchanger. The bypass circuit has a second solenoid valve. A control system activates the valves based on a capacity demand.

Abstract: A refrigerant flow-control valve operable between a no-flow condition and a flow condition in response to a control signal supplied thereto. The flow-control valve includes a tubular-shaped body forming a refrigerant passageway extending from an inlet to an outlet, a cylindrically-shaped restrictor secured within the tube and forming a restriction, and a cylindrically-shaped stop secured within the tube and forming a plunger valve flow passage. The stop is located downstream and spaced-apart from the restrictor and the restriction has a greater resistance to flow than the valve flow passage. A plunger is within the tube between the restrictor and the stop and carries a valve element. The plunger is movable between a first position closing the valve flow passage to generally prevent refrigerant flow therethrough and through the passageway and a second position opening the valve flow passage to permit refrigerant flow therethrough and through the passageway.

Abstract: A vapor compression system including a line for flowing heat transfer fluid, a compressor connected with the line for increasing the pressure and temperature of the heat transfer fluid, a condenser connected with the line for liquefying the heat transfer fluid, and an expansion device connected with the line for expanding the heat transfer fluid. The expansion device includes a housing defining a first orifice, and at least one blade connected with the housing, wherein the blade is movable between a first position and a second position, wherein the first orifice is larger in the first position than in the second position. The vapor compression system also includes an evaporator connected with the line for transferring heat from ambient surroundings to the heat transfer fluid.

Abstract: A vapor compression system having a line for flowing heat transfer fluid, a compressor and a condenser both connected with the line. The vapor compression system also has an expansion device connected with the line for expanding the heat transfer fluid. The expansion device has a housing defining a housing orifice and at least one ball within the housing. The ball forms at least two channels, wherein each channel defines a channel orifice. The effective cross-sectional area of the one channel orifice is greater than the effective cross-sectional area of the other channel orifice. Moreover, the ball is movable between a first position and a second position, wherein the housing orifice is effectively made larger in the first position than in the second position. The vapor compression system also has an evaporator connected with the line for transferring heat from ambient surroundings to the heat transfer fluid.

Abstract: A heat transmission retardant member 140 is formed of a cup-like shaped resin material utilizing nylon or polyacetals, comprising a collar 141 formed to the outside of the upper end thereof, and a thick-walled cylinder portion 143 having at the lower end thereof a tapered portion 142. Said retardant member 140 is positioned so that the upper end contacts a support member 82′, said collar 141 is supported by the inner surface of a housing 81, the outer surface of said cylinder portion 143 contacts the inner surface of said housing 81, and the end of said tapered portion 142 is inserted to a second hole 72 and contacting the outer surface of a heat-sensing driven member 100 and further positioned within a lower chamber 85 defined by a diaphragm 82.

Abstract: A condenser of a refrigerant cycle system includes a first heat exchange unit into which refrigerant discharged from a compressor flows, a second heat exchange unit disposed at a downstream of the first heat exchange unit in a refrigerant flow direction, and a gas-liquid separator disposed between the first and second heat exchange units in the refrigerant flow direction. In the refrigerant cycle system, at least gas refrigerant separated in the gas-liquid separator flows into the second heat exchange unit so that an amount of liquid refrigerant stored in the gas-liquid separator is changed in accordance with a super-heating degree of refrigerant discharged from the compressor.

Abstract: A heat transmission retardant member 140 which is a cylinder-shaped resin tube made of nylon or polyacetals is mounted between an adsorbent 40 and an inner wall of a hollow portion of a heat-sensing driven member 100 with a space 140′ between said inner wall. The hollow portion of said heat-sensing driven member 100 includes said adsorbent 40, said heat transmission retardant member 140 made of resin, and said space 140′. Said heat transmission retardant member 140 comprises plural protrusions, and by positioning said protrusions to contact said inner wall, said space 140′ is formed.

Abstract: A refrigerating cycle has a condenser, an evaporator, a variable displacement compressor, and an expansion valve. The variable displacement compressor is connected between the condenser and the evaporator to form the refrigerating cycle, and includes a control valve designed to provide a control valve characteristic sloping downward with increase in a discharge pressure. The expansion valve is connected between the condenser and the evaporator, to return a refrigerant from the condenser through the evaporator to the variable displacement compressor, and designed to provide an open valve characteristic whose slope is approximately equal to the downward slope of the control valve characteristic.

Abstract: An expansion device capable of preventing an abnormal increase in the high-pressure in a freezing cycle and having, as an integrated unit thereof, a mechanism capable of quickly responding to an abnormal increase in the high-pressure and the low-pressure is provided. A means for displacement (bellows) 28 which becomes displaced in correspondence to the high-pressure is linked to a valve element 24 of a restrictor valve mechanism 32 to displace a rod 34 provided with a safety valve mechanism 33.

Abstract: In a space cooling system having an evaporator in heat exchange relationship with a space to be cooled, a condenser external to the space, a compressor for circulating heat transfer fluid between the evaporator and condenser, an expansion valve for controlling the flow rate of heat transfer fluid through the evaporator, apparatus for automatically closing the expansion valve in response to a loss of electrical power to the system. The apparatus includes a storage capacitor for storing electrical energy when power is being supplied to the system, a voltage detector for detecting a loss of electrical power and a controller for controlling a step motor to close the expansion valve in response to a loss of system power. The capacitor automatically discharges in response to a power loss condition to supply power to the controller and step motor to enable the expansion valve to be closed. Therefore, refrigerant migration in the system, which can damage the compressor upon restart, is substantially inhibited.

Abstract: A vapor compression refrigeration system includes an evaporator, a compressor, and a condenser interconnected in a closed-loop system. In one embodiment, a multifunctional valve is configured to receive a liquefied heat transfer fluid from the condenser and a hot vapor from the compressor. A saturated vapor line connects the outlet of the multifunctional valve to the inlet of the evaporator and is sized so as to substantially convert the heat transfer fluid exiting the multifunctional valve into a saturated vapor prior to delivery to the evaporator. The multifunctional valve regulates the flow of heat transfer fluid through the valve by monitoring the temperature of the heat transfer fluid returning to the compressor through a suction line coupling the outlet of the evaporator to the inlet of the compressor.

Abstract: In an air conditioner including a compressor, a four-way valve, an outdoor heat exchanger, a pressure-reducing mechanism, an indoor heat exchanger and an accumulator which are successively connected to one another to construct a loop-like refrigerant circuit, non-azeotropic mixture refrigerant composed of first refrigerant having a high boiling point and second refrigerant having a low boiling point being filled in the refrigerant circuit and the flow of the non-azeotropic mixture refrigerant being inverted between cooling operation and heating operation by operating the four-way valve, when one of the outdoor heat exchanger and the indoor heat exchanger serves as an evaporator, the first refrigerant of the non-azeotropic mixture refrigerant is stocked in the accumulator while the second refrigerant of the non-azeotropic mixture refrigerant is circulated in the refrigerant circuit, thereby increasing the refrigerant pressure in the evaporator.

Abstract: A refrigeration system comprising a compressor for compressing a refrigerant. The compressor uses an oil for lubrication. A condenser receives the compressed refrigerant and condenses at most of the refrigerant to a liquid. A thermo-siphon vessel receives and stores refrigerant from the condenser. An oil cooler receives liquid refrigerant from the thermo-siphon vessel and uses the liquid refrigerant to cool the compressor oil. An air unit receives liquid refrigerant from the thermo-siphon vessel and uses the liquid refrigerant to cool an enclosure. A receiver receives and stores any overflow liquid refrigerant from the thermo-siphon vessel, vapor and liquid refrigerant from the oil cooler, and releases the overflow back to the air unit as needed. A valve before the receiver restricts the flow of refrigerant from the thermo-siphon vessel to maintain the pressure in the thermo-siphon vessel and receiver above a given point.

Abstract: In an expansion valve the pressure vessel of which is constituted by a reduced number of parts and which does not require seal members a valve unit is surrounded by first and second half shells which in turn are surrounded by a pressure vessel formed as a one-piece body by molding resin by an insert molding process. Since the resin constituting the resin molded one-piece pressure vessel simultaneously form internal sealing member structures no additional seal members are required to be positioned and mounted. The first and second half shells are shaped such that the necessary refrigerant passages for the valve unit are defined in communication with connection holes of the pressure vessel.

Abstract: A variable restrict valve is disposed at the upstream side of a refrigerant flow, a fixed restrictor is disposed at the downstream side of the variable restrict valve, an intermediate space is provided between the variable restrict valve and the fixed restrictor, a passage sectional area of the intermediate space is set to be larger than the fixed restrictor and passage length L of the intermediate space is set to be larger than a predetermined length required when the flow of refrigerant injected from the variable restrict valve expands more than the passage sectional area of the fixed restrictor.

Abstract: A connecting device for a heat exchanger which has a fluid circulating channel formed with an opening at one end thereof and an opening at the other end thereof, the openings being formed as juxtaposed in one side of the heat exchanger. The connecting device comprises a blocklike connector body having two horizontal through bores corresponding to the respective openings and fixed to the heat exchanger with the through bores in coincidence with the respective openings. A tubular member is fluid-tightly fitted in each of the through bores and has a connecting end projecting toward a connectable device. The connecting end is in the form of a spigot fittable in a socket of the connectable device.

Abstract: A temperature sensing portion of a control valve main body is located in a first refrigerant passage for communicating an outlet side of a radiator with an inlet side of an internal heat exchanger, and a second refrigerant passage for introducing the refrigerant flowing from the internal heat exchanger to an upstream side of a valve port in a refrigerant flow is formed in a casing main body. Accordingly, since it is possible to reduce a delay of temperature change in a sealed space (control chamber) with respect to refrigerant temperature change at the outlet side of the radiator, a temperature response characteristic of the pressure control valve is improved. Further, since it is not necessary to separately assemble a capillary tube, a temperature sensing cylinder or the like to the outlet side of the radiator, it is possible to reduce the number of processes for assembling the CO2 cycle and to attempt to reduce a manufacturing prime cost.

Abstract: The present invention provides a method and system for controlling and limiting the discharge temperature of a compressor of a refrigeration system. The invention is suitable for converting an existing refrigeration system which operates with one refrigerant to use with another refrigerant which can cause high discharge temperatures. The invention includes a simple four-part system—a temperature sensor to sense the discharge temperature, an injection valve for injecting liquid refrigerant into the suction gas line of the compressor, a fluid line for providing liquid refrigerant to the valve from the condenser and a digital controller for actuating the valve.

Abstract: A CO2 cycle system having a variable capacity compressor is controlled even when the refrigerant delivery capacity of the variable capacity compressor changes. When the refrigerant delivery capacity of the variable capacity compressor decreases, the aperture of an electric expansion valve is fixed for a predetermined time To. When the refrigerant delivery capacity has not changed, the aperture of the electric expansion valve is controlled so that the refrigerant temperature and pressure on the outlet side of a system heat exchanger change along an optimal control line. As a result, because the refrigerant delivery capacity Qd of the compressor is controlled in correspondence with the intake pressure Ps, i.e., the pressure on the side of the evaporator, without being influenced by control of the expansion valve side, the CO2 cycle system can be adequately controlled.

Abstract: An electronic variable orifice tube suitable for use as an expansion valve in a refrigeration system providing two flow rates in response to electronic control signals comprises a bodytube, a restrictor mounted within the bodytube and defining a first flowpath. A plunger is translatably positioned within the bodytube in proximity to the restrictor and defines a second and a third flowpath. A valve actuator is functionally coupled to the plunger to translate the plunger within the bodytube to transition between the two flow rates. A high flowpath is formed through the bodytube by the first, second, and third flowpaths, and a low flowpath is formed through the bodytube by the first and the second flowpaths to the exclusion of the third flowpath. A solenoid may be used as the valve actuator and a spring may be employed to return the plunger to its quiescent state when the solenoid is not energized.

Abstract: A system for controlling the amount of foam ingested to a compressor of a cooling system is presented. The present invention utilizes a heated thermistor to control an electrically positioned expansion valve feeding liquid refrigerant to a system evaporator. The thermistor is controlled to be a few degrees warmer than the discharge saturation temperature of the refrigerant exiting the compressor. The saturation temperature corresponding to the compressor discharge pressure is calculated by a microprocessor and compared to the thermistor temperature. If the difference is greater or less than desired, the microprocessor will send the proper signals to the electrically positioned expansion valve thereby controlling the rate of foam ingested by the compressor.

Abstract: When a compressor is stopped, a refrigerant passage in which refrigerant flows from a radiator to an evaporator is closed by a pressure control valve. Accordingly, even after the compressor is stopped, a high-pressure side pressure can be prevented from decreasing. This does not cause increased manufacturing cost of a supercritical refrigerating system.

Abstract: The supercritical refrigerating circuit has a first pressure reducing valve for reducing pressure of refrigerant flows into a first evaporator and a second pressure reducing valve for reducing pressure of refrigerant flows into a second evaporator. The first pressure reducing valve further controls refrigerant pressure at an outlet of a gas cooler. Accordingly, the supercritical refrigerant circuit is controlled without increasing the number of the pressure reducing valve.

Abstract: A flow regulating valve (100) for an air conditioning system is shown in which a body member (104) is provided with a fixed passageway (104a) and a variable passageway (104b) which results in regulating flow of refrigerant into the evaporator of the air conditioning system. Under high ambient and low or idle speeds, the system refrigerant pressure rises. This increases pressure in the evaporator and an increase in the saturation temperature of refrigerant in the evaporator. This increase in temperature is sensed by a helical thermostatic metal element (110) which moves to rotate an inlet sleeve (112) having a web (104c) formed between first and second windows (112a, 112b) to move into alignment with the inlet port (104c) of passageway (104b) to increase restriction to the flow of the refrigerant fluid through the valve thereby decreasing pressure of the refrigerant entering the evaporator.

Abstract: A dry suction refrigeration system includes an evaporator fed with liquid refrigerant which discharges a vapor refrigerant to an accumulator. A compressor receives vapor refrigerant from the accumulator and compressies the vapor refrigerant. A condenser receives the compressed vapor refrigerant from the compressor and transforms the refrigerant into liquid refrigerant. A receiver receives the liquid refrigerant from the condenser and supplies it to the evaporator. The evaporator includes an electronic expansion valve operable to continuously monitor the evaporation of liquid refrigerant in the evaporator and to continuously meter the flow of liquid refrigerant, so as to cause a complete vaporization of the liquid refrigerant. Because the liquid refrigerant is completely evaporated, the vapor refrigerant is moved through the system by pressure differential alone.

Abstract: A pressure control valve controlling the temperature and pressure at the outlet side of a heat emitter so as to enable efficient operation by a CO.sub.2 system operating at the super critical region, wherein CO.sub.2 is sealed in a closed space at one side of a diaphragm moving the valve element at a density of approximately 600 kg/m.sup.3, a through member made of a material with a high heat conductivity is provided extending between the inside and outside of the closed space, and step differences are eliminated at the contact surfaces to improve the durability of the diaphragm.

Abstract: An air conditioner in accordance with the invention comprises a first unit including a compressor and a heat exchanger; a second unit including a heat exchanger; a refrigerant circuit connecting the compressor and the heat exchanger of the first unit, with the heat exchanger of the second unit, through which a refrigerant flows; a refrigerant pressure reduction valve disposed in the refrigerant circuit and provided in the second unit; a control unit provided in the first unit for controlling the refrigerant pressure reduction valve in the second unit.

Abstract: A self-contained refrigeration system utilizes a solenoid valve to meter refrigerant to a thermal process, the thermal process to be maintained at a predetermined temperature. When cooling of the thermal process is not required, refrigerant is recycled without coming into thermal contact with the thermal process by way of a hot gas bypass valve.

Abstract: A control apparatus for a gas injection type air conditioning system that prevents lowering of compressor speed and cycle stoppage under conditions where high pressure is liable to occur. During a system heating mode, a pressure change rate ASP of the high pressure of the refrigerating cycle is calculated. When a pressure change rate .increment.SP rises above a predetermined value, a system electric expansion valve aperture is reduced. Accordingly, by calculation of the pressure change rate .increment.SP, it is possible to control the electric expansion valve in the above manner earlier than in prior art control schemes when there is a sudden rise in the high pressure.

Abstract: A cryostat (10') with a heat exchanger (13'); a valve (25') for controlling the flow of fluid through said heat exchanger (13'); and a snap disk (30') for actuating the valve (25'). In a specific embodiment, the snap disk (30') is constructed of at least two different materials (32', 34'), each having a different coefficient of thermal expansion. The snap disk (30') is mounted upon an orifice block (38') and coupled to a needle valve (25') by a connecting rod (40'). The needle valve (25') engages an orifice (16') in the orifice block (38'). The orifice (16') is in communication with the tubing (14') of a heat exchanger (13') via a channel (44') in the orifice block (38'). The geometry of the snap disk (30') is such that when the disk changes state, it snaps due to the thermal properties thereof. This ensures fast response with abrupt closure characteristics and considerable travel. In addition, the snap disk (30') allows for a simplified cryostat design with minimal weight and cost.

Abstract: A refrigerating system of vapor compression type operating at a super critical area, while obtaining an increased efficiency. The refrigerating system includes a pressure control means for controlling the temperature and the pressure at the outlet of a heat emitter. The pressure control valve responds to a pressure difference between the inlet pressure of the refrigerant to the pressure control valve and the pressure in an outwardly sealed chamber in which the refrigerant is filled such that, with respect to the volume of the chamber under closed condition of the pressure control valve, a density of the refrigerant is in a range between a density of a saturated liquid at a temperature of 0.degree. C. and a density at the critical point of the refrigerant. As a result, the pressure and the temperature at the outlet of the heat emitter is controlled substantially along the optimum control line .eta.max, resulting in an effective execution of a refrigerating cycle at the critical area.

Abstract: Apparatus for detecting working fluid state in a heat transfer system of the type having an evaporator and an expansion valve for controlling mass flow of the working fluid to the evaporator, comprises a first sensor disposed in the working fluid on the outlet side of the evaporator; the first sensor producing a first signal related to the working fluid state; a second sensor disposed in the working fluid on the inlet side of the evaporator; the second sensor producing a second signal related to a pressure dependent characteristic of the working fluid; and a control circuit for receiving the first and second signals and determining the working fluid state based on a ratio of the first and second signals.

Abstract: According to the present invention, in an expansion valve integrated with a electromagnetic valve, there are provided an inlet refrigerant path, a restriction path for decompressing and expanding the refrigerant from the inlet refrigerant path, a valve element for adjusting an opening degree of the restriction path, a diaphragm operating unit, and an outlet refrigerant path for supplying the refrigerant decompressed and expanded in the restriction path to an evaporator. The outlet refrigerant path is opened or closed by the electromagnetic valve 200. When the electromagnetic valve 20 is closed, the diaphragm operating unit operates to close the valve element in the restriction path, based on the refrigerant pressure between the valve element of the electromagnetic and the restriction path. In this way, it is possible to reduce the noise of the refrigerant when the electromagnetic valve is closed.

Abstract: Chiller operating efficiency is optimized by controlling the system to maintain the condenser liquid refrigerant level at a value which will minimize or prevent gas bypass to the evaporator. This is accomplished by sensing the level of liquid refrigerant in the condensor and incorporating fuzzy logic to properly position a multi-position valve which can variably restrict the flow of this liquid into the evaporator, according to this sensed parameter. The fuzzy logic utilizes as inputs both the level error from a set point level and the rate of change of the sensed level. Each of these inputs are combined by fuzzy logic techniques to provide the required output signal to control the opening and closing of the valve.

Abstract: A thermal expansion valve for automotive coolant systems which is significantly more compact than previously developed expansion values. The housing of the expansion valve is divided into a first housing formed in a cylindrical shape with a bottom and a second housing formed in a columnar shape. The first housing is fit into the second housing, and both are integrally connected to each other. A temperature sensing mechanism having a temperature sensing chamber and an expansion mechanism for adjusting an opening degree of a throttle passage in accordance with an evaporator outlet temperature sensed by the temperature sensing means are disposed in the second housing. First and fourth joint portions connected to inlet and outlet refrigerant pipes of the evaporator, respectively, are at the bottom of the first housing.

Abstract: The present invention is a method for controlling oil lubricant pressure of a screw type compressor in an air conditioning system. In response to a low oil pressure condition, evaporator pressure is lowered to increase the pressure differential across a compressor, to thereby bring about an increase in oil pressure. Evaporator pressure can be lowered by decreasing the maximum operating pressure of the evaporator, and by throttling an expansion valve by the amount required to lower the evaporator pressure in accordance with the reduced maximum operating setpoint.

Abstract: A refrigeration system including a flow control expansion valve. A valve body defines a valve inlet for accepting refrigerant and a valve outlet for delivering refrigerant that has passed through the valve body. A metering head defines first and second passageways for fluid passing through the valve body. A cylindrical sleeve is mounted for controlled movement within the valve body and including a center passageway which in combination with the first and second passageways conveys fluid through the valve body to the valve outlet. A spring urges the sleeve in a direction relative the metering head to maintain both the first and second passageways in fluid communication with the center passageway of the sleeve.

Abstract: In an air conditioning apparatus employing a heat pump system in which a cooling evaporator and a heating condenser are disposed inside the compartment. A compressor is provided with a gas injection port, a fixed throttle for reducing pressure of refrigerant on high pressure side in a refrigerating cycle to middle pressure, and a gas-liquid separator for separating the middle pressure refrigerant of which pressure is reduced by the fixed throttle. The gaseous refrigerant separated by the gas-liquid separator is introduced into the gas injection port. In a heating operation, the refrigerant circulates through the compressor, the condenser, the fixed throttle, the gas-liquid separator, an expansion valve, an outdoor heat exchanger, and the compressor as a closed circuit, while the gaseous refrigerant separated by the gas-liquid separator is injected into the compressor through the gas injection port. As a result, when the outside air temperature is low, the heating capacity is improved.

Abstract: In the heating operation mode, the condensed temperature is calculated by the value of the discharged pressure sensor disposed at the discharge side of the compressor. Based on a difference between the condense temperature and a value of the outlet temperature sensor for detecting the refrigerant having passed through the heating indoor heat exchanger, the supercooling degree is calculated. Then, an opening degree of the expansion valve for heating is controlled so that the calculated supercooling degree is set to a target supercooling degree. Thus, since the condensed temperature is calculated by employing a high responsive pressure sensor, an error in the calculation of the condensed temperature can be reduced, thereby reducing an error in the calculation of the supercooling degree.

Abstract: A flash tank economizer containing a first expansion device to expand high pressure refrigerant from a system condenser to an intermediate pressure and a second expansion device for further expanding liquid refrigerant at the intermediate pressure that has collected in the tank to a desired low pressure for delivery to the system evaporator. Vapor phase refrigerant produced by the first expansion in the tank is injected back into the system compressor at the intermediate pressure.

Abstract: An air conditioner comprises a first unit including a compressor and a heat exchanger, a second unit including a heat exchanger, a refrigerant circuit connecting the compressor and the heat exchanger of the first unit, with the heat exchanger of the second unit, through which a refrigerant flows, a refrigerant pressure reduction valve disposed in the refrigerant circuit and provided in the second unit, a control unit provided in the first unit for controlling the refrigerant pressure reduction valve in the second unit.

Abstract: A heat pump apparatus includes a liquid refrigerant flow control valve connected in fluid communication between a condenser and evaporator. The liquid flow control valve includes a refrigerant outlet tube connected in fluid communication with an expansion orifice and extends in thermal contact with an upper portion of the valve housing for controlling condensing of vapor refrigerant within the housing to thereby stabilize refrigerant flow. A float, movably positioned within the housing, cooperates with the expansion orifice for controlling a flow of refrigerant passing from the housing to the evaporator based upon a level of liquid refrigerant within the housing. When a large amount of vapor refrigerant arrives at the liquid flow control valve as a result of a control oscillation or system disturbance, the float moves downwardly, thereby reducing flow through the expansion orifice, cooling the outlet tube and causing vapor to condense more quickly in the housing.

Abstract: The microprocessor-based HVAC control system detects sensor faults by comparing thermistor readings with predetermined extreme values, indicative of sensor fault. The system automatically selects the appropriate combination of automatic/preset modes of operating key system components such as the expansion valve, the demand defrost system and the indoor fan speed control system. With a view towards minimizing any negative impact on system performance and reliability in the event of sensor malfunction.