Abstract: A defrost system for a temperature controlled storage unit includes an enclosure providing a space for storage of products. A refrigeration system has a supply line and a return line coupled to a cooling element to circulate a refrigerant through the cooling element to provide cooling to the space. A control module initiates a plurality of defrost modes on a predetermined frequency and for a predetermined duration by reducing a flow rate of the refrigerant through the cooling element so that a superheat temperature of the refrigerant in the cooling coil is increased to a predetermined range.

Abstract: The invention relates to a shut-off valve for an expansion valve (11) in refrigerating systems, in particular vehicle air conditioning systems, having a regulating screw (31), having a receiving section (32), which is arranged at one end of the regulating screw (31) and is intended for the fitting of a travel-generating device (33) which actuates a valve (47) arranged in the regulating screw (31) and opens and closes a first passage opening (53) between an inlet (61) and an outlet (63) of the regulating screw (33), and having a regulating space (76) which is connected downstream of the valve (47) in the direction of flow of a refrigerant and is designed for receiving at least one regulating device (78).

Abstract: The present invention relates to a monitoring system for connection to an air conditioning system. The monitoring system includes a primary monitor for sensing the suction temperature and suction pressure of the air conditioning system along with the air conditioning unit temperature. In addition, the monitoring system includes a remote sensing device that is placed in the structure to monitor and transmit return air temperature and relative humidity to the primary monitor. The collected data is then used to calculate the superheat condition of the air conditioning system which is related to its efficiency.

Abstract: A vapor compression system includes a main vapor compression circuit having a compressor, a condenser, an expansion device and an evaporator serially connected by main refrigerant lines, the compressor having a suction port, a main discharge port and an intermediate port, and the main refrigerant lines being communicated with the main discharge port and the suction port; a bypass circuit communicated between the intermediate port and the suction portion; and a superheat sensing device positioned to sense superheat in a combined flow from the main vapor compression circuit and the bypass circuit. A method of operation of the system is also provided. The benefits of enhanced system and compressor performance, improved compressor reliability and extended system operating envelope are readily obtained.

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

Abstract: A new feedback linearization approach to advanced control of single-unit and multi-unit HVAC systems is described. In accordance with the approach of the invention, this new nonlinear control includes a model-based feedback linearization part to compensate for the nonlinearity in the system dynamics. Therefore, the evaporating temperature and superheat values can be controlled by linear PI control designs to achieve desired system performance and reliability. The main advantages of the new nonlinear control approach include (1) better performance even with large model errors, (2) being able to adapt to indoor unit turn on/off operation, (3) much smaller PI control gains compared to that of current feedback PI controls, (4) much easier design procedures since there is no need for tuning the PI control gains over wide range operation.

Abstract: The object of the present invention is to provide a solenoid valve-equipped expansion valve simplified in construction. A common valve element in which a valve element of an expansion valve and a valve element of a stop valve are integrally formed as a unitary member is disposed such that the common valve element can be axially movably guided by a shaft having the driving force of a power element transmitted thereto. A first core of a solenoid, holding the common valve element, is urged by a spring such that the common valve element is seated on a valve seat. When the solenoid is energized, the first core holding the common valve element is attracted by a second core rigidly fixed to the shaft such that the common valve element operates with the shaft in an interlocked fashion. As a result, when the solenoid is deenergized, the common valve element can function as a stop valve, whereas when the solenoid is energized, the common valve element can function as an expansion valve.

Abstract: A refrigeration system includes a compressor, a gas cooler, an expansion device, and an evaporator. Refrigerant is circulated though the closed circuit system. Preferably, carbon dioxide is used as the refrigerant. As carbon dioxide has a low critical point, systems utilizing carbon dioxide as a refrigerant usually require the refrigeration system to run transcritical. When the system is operating inefficiently, the system is modified so the system operates efficiently. First, a parameter of the system is monitored by a sensor and the then compared to a stored value to determine if the system is operating inefficiently. If the system is operating inefficiently, the system is modified to an efficient system.

Abstract: The object of the present invention is to provide a method of operating a refrigeration cycle which is capable of preventing oil from staying in an evaporator and ensures high coefficient of performance as well as sufficient circulation of oil. An electronic expansion valve is controlled such that during normal operation, refrigerant is always in a superheated state at the outlet of an evaporator, and the refrigerant is periodically forced to have negative superheat for a predetermined time by a superheat control device. Thus, during normal operation, the refrigerant sucked into a variable displacement compressor always has superheat, whereby the refrigeration cycle can operate with high coefficient of performance and an engine driving the variable displacement compressor can be operated at high fuel efficiency. Also, the refrigerant is temporarily controlled so as to have negative superheat.

Abstract: Disclosed are an air conditioner in which one or more compressors are operated so that the refrigerant compression capacity of the operating compressor(s) is variably changed in accordance with a cooling or heating load for cooling or heating air in a room, and a method for controlling an electronic expansion valve of the air conditioner.

Abstract: A vapor compression system (10) including an evaporator (16), a compressor (12), and a condenser (14) interconnected in a closed-loop system. In one embodiment, a multifunctional valve (18) is configured to receive a liquefied heat transfer fluid from the condenser (14) and a hot vapor from the compressor (12). A saturated vapor line (28) connects the outlet of the evaporator (16) and is sized so as to substantially convert the heat transfer fluid exiting the multifunctional valve (18) into a saturated vapor prior to delivery to the evaporator (16). The multifunctional valve (18) regulates the flow of heat transfer fluid by monitoring the temperature of the heat transfer fluid returning to the compressor (12) through a suction line (30) coupling the evaporator (16) outlet to the compressor (12) inlet. In one preferred embodiment, a bifurcated liquid line connects the condenser (14) outlet to the first inlet of an multifunctional valve and the inlet of a metering unit.

Abstract: An evaporator 10 of an air conditioner comprises a refrigerant entrance port 12 and a refrigerant exit port 14. A division wall 16 of the evaporator is extended to form a housing 200. The housing 200 comprises an inlet 210 for the refrigerant traveling from a compressor, an outlet 220 communicating with the entrance port 12 of the evaporator, and a refrigerant path 230 returning from the evaporator. The cassette unit 100 comprises a pipe member 110, a flange member 120 and a lid member 130, with major components of the expansion valve such as a diaphragm and a driving member for driving a valve means assembled thereto. The cassette unit 100 is accommodated in a hole 240 with steps of the housing 200 to complete the expansion valve.

Abstract: A system and method for cooling a room configured to house a plurality of computer systems. A plurality of evaporator units are arranged in series and are configured to receive air from the room and to deliver air to the room. The evaporator units are supplied with refrigerant operable to cool the received air in the evaporator units. At least one of the temperature of the refrigerant supplied to the evaporator units and the air delivery to the room may be controlled in response to temperatures sensed at one or more locations in the room.

Abstract: An expansion valve 1 comprises a piping member 10 having passages to which pipes for refrigerant are connected, and a cassette unit 100, which are formed as separate components. The cassette unit 100 comprises a flange portion 111 and a tube member 110 which are welded together, and to the interior of which are fixed a guide member 170, an orifice member 180 and a plate member 166. According to the pressure of gas filled in a gas charge chamber 122 defined by a lid 120 and a diaphragm 130, the diaphragm 130 is displaced, the movement of which is transmitted through a stopper 140 to a shaft member 150. The shaft member 150 is guided by a guide member 170 and drives a valve member 160 disposed within a valve chamber 161. The cassette unit 100 is inserted to the piping member 10 and fixed by a ring 50. Seal members 62, 64, 66 are fit to necessary areas.

Abstract: An expansion valve 1 comprises a piping member 10 having passages to which pipes for a refrigerant are connected, and a cassette unit 100, which are formed as separate components. The cassette unit 100 comprises a tube member 110 accommodating a guide member 170, an orifice member 180 and a plate member 166. A diaphragm 130 sandwiched between a rising portion 121 of a lid 120 and an end 110?c of the tube member 110 and defining a gas charge chamber 122 is displaced, the movement of which is transmitted to a shaft member 150. The shaft member 150 is guided by a guide member 170 and drives a valve member 160 disposed within a valve chamber 161. The cassette unit 100 is inserted to the piping member 10 and fixed by a ring 50. Seal members 62, 64, 66 are disposed to necessary areas.

Abstract: A compressor has an economizer injection line communicating into the compressor compression chambers. An unloader valve selectively communicates the economizer injection line back to a point upstream of the evaporator. When the compressor is run in unloaded mode, partially compressed refrigerant is thus returned to a point upstream of the evaporator. In unloaded mode, this results in a higher refrigerant mass flow through the evaporator, as compared to prior art where the bypassed refrigerant was returned downstream of the evaporator. This increases system efficiency by more effectively returning oil which otherwise might be left in the evaporator back to the compressor. Also, the amount of refrigerant superheat entering the compressor in unloaded operation is reduced as compared to the prior art compressor systems, wherein the bypassed refrigerant is returned directly to the compressor suction line.

Abstract: A refrigerant assembly includes a block-type thermostatic expansion valve and one or more refrigerant tubes. The body of the block valve has a port extending inwardly from one surface, and a refrigerant tube is received in the port. The refrigerant tube includes an annular bead, which is closely received within a counterbore coaxial with the bore. The surface of the body surrounding the counterbore is then mechanically deformed, preferably by staking, around the entire circumference of the refrigerant tube such that body material is forced radially inward toward the tube. The body material at least partially encloses the refrigerant tube bead within the counterbore to secure the refrigerant tube to the valve body. A sharp edge between the counterbore and bore is forced against the junction between the bead and the refrigerant tube to provide a fluid tight seal.

Abstract: A controller for an expansion valve of a refrigeration system for cooling a medium is configured to include, in the generation of a control signal, a measure of the evaporation temperature (T0) of the refrigerant in an evaporator and a measure of a property of the cooled medium, preferably without influence from a measure of the superheat temperature (SH) of the refrigerant. The controller comprises a PI-element for integrating and for producing a control signal for the expansion valve for controlling the flow of refrigerant into the evaporator, the PI-element being arranged in an inner control loop, a reference for which is produced by an outer control loop. The controller allows for fast response to disturbances and/or fast response of the medium temperature when the operating conditions of the refrigeration system are changed and/or fast response during start-up of the refrigeration system and maintains stable operation conditions with low, but positive superheating and a stable evaporation pressure.

Abstract: Thermostatic expansion valve for a vehicle air-conditioning system including a housing and a power element supported by the housing. The power element includes a diaphragm, and a pressure pad disposed against the diaphragm. The pressure pad may be formed in one piece from copper, a copper alloy, or another material, which material may also be a blend, composite, mixture, or other combination, having a thermal conductivity of at least about 800 BTU-in/hr-ft2-° F. (115 W/m-K), and preferably 1200 BTU-in/hr-ft2-° F. (170 W/m-K), and more preferably at least about 2000 BTU-in/hr-ft2-° F. (280 W/m-K), and a density of at least about 0.3 lb/in3 (8 g/cm3), and is connected via a stem to a valve element in the housing to control the refrigerant flow between the condensor and evaporator. The use of such material in the pressure pad reduces the susceptibility of the valve to external temperature changes and reduces the hunting of the valve.

Abstract: A system and method for cooling a room configured to house a plurality of computer systems. A plurality of evaporator units are arranged in parallel and are configured to receive air from the room and to deliver air to the room. The evaporator units are supplied with refrigerant operable to cool the received air in the evaporator units. The air may be controlled in response to temperatures sensed at one or more locations in the room.

Abstract: An air conditioning unit including an expansion device (4) of the refrigerating fluid loop controlled to set the internal heat exchanger efficiency &eegr;, represented by the equation: &eegr;=TccTsc/TsrTsct, wherein: TccTsc and Tsr are respectively temperatures at the compressor input (1), and at the evaporator output (5) and at the fluid cooler output (2), at a reference value such that the fluid leaves the evaporator in a completely gaseous state and without overheating.

Abstract: An expansion valve 1 comprises a housing 10 having refrigerant paths and a cassette unit 100. The cassette unit 100 comprises a flange 111 and a tube member 110 formed integrally thereto. An adjustment plate member 266 is mounted to the small-diameter end of the tube member 111 having steps, the plate member having an external thread 266a formed thereto. A bottom portion 46 of the inner bore of the housing for mounting the cassette is provided with an internal thread 46a. A head portion 121 of the lid member 120 of the cassette unit has a hexagonal shape, which enables the cassette unit 100 to be screwed onto the housing 10 using a tool such as a wrench.

Abstract: A new feedback linearization approach to advanced control of single-unit and multi-unit HVAC systems is described. In accordance with the approach of the invention, this new nonlinear control includes a model-based feedback linearization part to compensate for the nonlinearity in the system dynamics. Therefore, the evaporating temperature and superheat values can be controlled by linear PI control designs to achieve desired system performance and reliability. The main advantages of the new nonlinear control approach include (1) better performance even with large model errors, (2) being able to adapt to indoor unit turn on/off operation, (3) much smaller PI control gains compared to that of current feedback PI controls, (4) much easier design procedures since there is no need for tuning the PI control gains over wide range operation.

Abstract: An orifice member 10 disposed at an orifice 32a of a valve body 30 is formed of a material such as stainless steel harder than the aluminum material forming valve body 30. Orifice member 10 is substantially cylindrical, with one open end 10a having a flat surface that comes in planar contact with a contact surface of valve body 30 constituting orifice 32a, and the other open end being tapered so as to oppose to a valve member 32d. A screw portion is formed to the outer side of orifice member 10 enabling it to be engaged to a screw portion formed on orifice 32a of valve body 30. The joint can be secured by applying and curing an adhesive between orifice member 10 and orifice 32a. Since orifice member 10 comes in planar contact with valve body 30 having an anodized aluminum film, the film is not damaged by orifice member.

Abstract: A refrigerant assembly includes a block-type thermostatic expansion valve and one or more refrigerant tubes. The body of the block valve has a port extending inwardly from one surface, and a refrigerant tube is received in the port. The refrigerant tube includes an annular bead, which is closely received within a counterbore coaxial with the bore. The surface of the body surrounding the counterbore is then mechanically deformed, preferably by staking, around the entire circumference of the refrigerant tube such that body material is forced radially inward toward the tube. The body material at least partially encloses the refrigerant tube bead within the counterbore to secure the refrigerant tube to the valve body. A sharp edge between the counterbore and bore is forced against the junction between the bead and the refrigerant tube to provide a fluid tight seal.

Abstract: A refrigeration system allows the refrigerant to circulate through a closed circulation channel. A dry evaporator is incorporated in the circulation channel. The dry evaporator is designed to keep a quality smaller than 1.0 in evaporating the refrigerant. The quantity of heat transfer per unit area, namely, a heat transfer coefficient depends on the quality. The heat transfer coefficient remarkably drops when the quality of the refrigerant exceeds a predetermined threshold level before the quality actually reaches 1.0. The quality of the refrigerant kept below the predetermined threshold level during vaporization of the refrigerant in the dry evaporator allows a reliable establishment of a higher performance of cooling. On the other hand, if a refrigerant completely evaporates in a dry evaporator in a conventional manner, the heat transfer coefficient of the refrigerant remarkably drops after the quality of the refrigerant exceeds the predetermined threshold level.

Abstract: An expansion valve is controlled in response to sensing conditions at the outlet of at least one compressor within a refrigeration loop in a manner that achieves low suction superheat operation of the compressor. In particular, a discharge superheat is computed using data obtained from a specific mathematical model of the compression process corresponding to the current capacity stage of the compressor. The position of the expansion valve is controlled so as to result in an actual discharge superheat being within a predetermined dead band amount of the computed discharge superheat.

Abstract: An air conditioner for an economically running vehicle includes a compressor driven by a vehicle engine, an evaporator, and a cold-storage heat exchanger having a cold storage material. The evaporator and the cold-storage heat exchanger are disposed in series in a refrigerant flow. When the compressor is operated, the cold storage material is cooled by low-pressure refrigerant in a cold storage mode. When the operation of the compressor is stopped, refrigerant circulates between the evaporator and the cold-storage heat exchanger, so that refrigerant evaporated in the evaporator is cooled and liquefied by the cold storage material in a cold release mode. Further, a flow direction of refrigerant flowing through the evaporator in the cold storage mode is the same as that in the cold release mode.

Abstract: A system and method for cooling a room configured to house a plurality of computer systems. A plurality of evaporator units are arranged in series and are configured to receive air from the room and to deliver air to the room. The evaporator units are supplied with refrigerant operable to cool the received air in the evaporator units. At least one of the temperature of the refrigerant supplied to the evaporator units and the air delivery to the room may be controlled in response to temperatures sensed at one or more locations in the room.

Abstract: An object of the present invention is to improve a heat exchanging capability in an evaporator in a refrigerant cycle system in which a high pressure side is operated at a supercritical pressure. The refrigerant cycle system is a refrigerant cycle system in which a compressor, a gas cooler, an expansion valve and an evaporator are sequentially connected in a cyclic form and a high pressure side is operated at a supercritical pressure, wherein the degree of opening of the expansion valve is adjusted based on the temperature and pressure of a refrigerant at an outlet of the evaporator so as to control the degree of superheat at the outlet of the evaporator. An abstract of the present invention is to make large the degree of superheat at the outlet of the evaporator by means of the expansion valve.

Abstract: An expansion valve 1 comprises a piping member 10 equipped with passages to which refrigerant pipes are to be connected, and a cassette unit 100, the two members being formed as separate units. The cassette unit 100 comprises a tube member 110 having a flange portion 111, and at the interior of the tube member 110 are fixed a guide member 170, an orifice member 180, and a plate member 166. The pressure of gas filled in a gas charge chamber 122 defined by a lid 120 and a diaphragm 130 displaces the diaphragm 130, the displacement being transmitted to a shaft member 150 through a stopper member 140 including at the center thereof a tubed portion 142 storing an absorbent. The shaft member 150 is guided by a guide member 170 and controls the valve means 160 inside a valve chamber 161. The cassette unit 100 is inserted to the piping member 10 and fixed to position by a ring 50. Seal members 62, 64, and 66 are equipped to appropriate areas between the cassette unit and the piping member.

Abstract: The object of the present Invention is to provide an expansion valve including a pressure sensor which enables reduction of parts cost. A pressure sensor is screwed into an opening of a body block, which communicates with a space accommodating a valve element and a compression coil spring for urging the valve element toward a valve seat. A set value for an expansion valve is adjusted by changing the amount of screwing of the pressure sensor to thereby change the load of the compression coil spring. An adjusting screw for adjusting the set value for the expansion valve can be dispensed with, which makes it possible to reduce the manufacturing costs of the expansion valve.

Abstract: An air conditioner for an economically running vehicle includes a compressor driven by a vehicle engine, an evaporator, and a cold-storage heat exchanger having a cold storage material. The evaporator and the cold-storage heat exchanger are disposed in series in a refrigerant flow. When the compressor is operated, the cold storage material is cooled by low-pressure refrigerant in a cold storage mode. When the operation of the compressor is stopped, refrigerant circulates between the evaporator and the cold-storage heat exchanger, so that refrigerant evaporated in the evaporator is cooled and liquefied by the cold storage material in a cold release mode. Further, a flow direction of refrigerant flowing through the evaporator in the cold storage mode is the same as that in the cold release mode.

Abstract: A vapor compression refrigeration and freezer system includes a compressor, a condenser, an expansion devise and an evaporator which includes an evaporator coil having an inlet and an outlet which coil is in heat exchange relation with an air medium along substantially the entire coil length. The inlet to the evaporator coil is in flow communication with an outlet of the expansion devise via an evaporator feedline.

Abstract: A system and method for preventing hunting of a thermal expansion valve used to control the flow of refrigerant supplied to an evaporator in a refrigeration cycle. A refrigeration apparatus is provided with a compressor, a condenser, a receiver, an expansion valve, and an evaporator connected in this order, spherically activated carbon made of phenol having pore sizes fit for molecular sizes of a working fluid is prepared; and the spherically activated carbon is provided into the expansion valve; whereby hunting, or the repeated opening and closing of the expansion valve, is prevented.

Abstract: A cooling air circulating device of a refrigerator is provided. According to the cooling air circulating device, it is possible to impartially cool a chilling chamber and to make the spread of temperature of the chilling chamber uniform by letting cooling air sucked up into the respective cells divided by shelves of the chilling chamber. Also, it is possible to rapidly cool the chilling chamber and to reduce time for cooling the chilling chamber by minimizing time, for which the cooling air whose temperature has risen above a predetermined temperature stays in the chilling chamber.

Abstract: A thermal expansion valve 100 comprises a square column shaped valve body 110, and the valve body 110 contains a first passage 120 with a bottom to which the refrigerant is introduced, a valve chamber 122 formed near the bottom of the passage, a second refrigerant passage 126 traveling toward the evaporator, and a third refrigerant passage 128 returning from the evaporator. A valve means 130 equipped within the valve chamber is fixed to the working rod 132 and operated by a power element 160. The working rod 132 comprises a small-diameter portion 135, and the valve means 130 is fixed by a welding process W1 thereto with a valve seat 200 equipped in advance. The valve seat member 200 is press fit using the working rod 132 to a hole 116 formed to the valve body.

Abstract: An expansion valve unit which prevents a temperature-sensing error from occurring due to transmission of a temperature lowered by the expansion of the refrigerant to a temperature-sensing chamber. An expansion valve unit is configured such that a high-pressure refrigerant guide groove is formed circumferentially in a body between a temperature-sensing chamber and a low-pressure refrigerant passage so as to guide a high-temperature and high-pressure refrigerant from the high-pressure refrigerant guide groove to a valve hole by way of a high-pressure refrigerant passage.

Abstract: Disclosed herein is a system and method for controlling the degree of superheat of an air conditioner. The air conditioner includes a compressor controlled in a pulse width modulation manner according to duty control signals, a condenser, an electronic expansion valve and an evaporator so as to form a refrigeration cycle. An entrance temperature sensor situated at the entrance of the evaporator and an exit temperature sensor situated at the exit of the evaporator are connected to a control unit. The control unit calculates the degree of superheat of the evaporator using the difference between mean entrance and exit temperatures of the evaporator sensed by the entrance temperature sensor and the exit temperature sensor for a period of time corresponding to a duty cycle period of the compressor, and regulates the opening of the electronic expansion valve according to the calculated degree of superheat.

Abstract: The object of the present Invention is to provide an expansion valve including a pressure sensor which enables reduction of parts cost. A pressure sensor is screwed into an opening of a body block, which communicates with a space accommodating a valve element and a compression coil spring for urging the valve element toward a valve seat. A set value for an expansion valve is adjusted by changing the amount of screwing of the pressure sensor to thereby change the load of the compression coil spring. An adjusting screw for adjusting the set value for the expansion valve can be dispensed with, which makes it possible to reduce the manufacturing costs of the expansion valve.

Abstract: A combined cooling and heating system having a simple design of a combined cooling and heat pump plant, especially for the heating and cooling of the passenger cells of motor vehicles. The concept of the invention is that the combined cooling and heat pump plant has a decompression device that fulfills the functions of a decompression device and a mode switch. The advantage of the invention is that dependent on the direction of flow, and thus the operational mode of the device, the decompression function and the blocking function, or the pressure relief function are realised by one component, the decompression device.

Abstract: A thermal expansion valve includes an adsorbent 40′ placed inside a temperature sensing unit 70, wherein an activated carbon having pore sizes fit for the molecular sizes of a temperature-responsive working fluid sealed inside the temperature sensing unit 70 is utilized as said adsorbent 40′, so that the adsorption quantity of the adsorbent will be fixed.

Abstract: A valve body 30 of an expansion valve 10′ is equipped with a first passage 32′ formed by a cutting process through which a high-pressure refrigerant travels, and on the lower portion of the valve body 30 is formed a space 35a defining a valve chamber 35′ from the bottom portion of the valve body 30 along the axial direction by a passage 33. The passage 33 defining the space 35a and the first passage 32′ are formed so as to interfere with each other, and at the interference area is formed a throttle portion 323. That is, the diameter of the first passage 32′ is formed so that the cross-sectional area thereof is gradually reduced toward the direction of the valve chamber 35, and a throttle portion 323 is formed to the area of the first passage 32′ interfering with the passage 33 defining the valve chamber 35′. The throttle portion 323 is formed to have a cross-sectional area corresponding to a diameter of approximately 3 mm.

Abstract: A combination refrigerant expansion valve adapted for operation by a thermally responsive element, and a solenoid actuated, preferably pilot operated inlet shutoff valve. The solenoid has a resilient elastomeric stop-ring for cushioning deceleration and limiting travel of the armature to prevent closing of the working air gap between the armature and a pole piece. The armature also has a cross port therethrough to alleviate flow-induced pressure decrease on the distal end of the armature from causing the armature to stick in the actuated position when the coil is de-energized.

Abstract: A combination refrigerant expansion valve adapted for operation by a thermally responsive element, and a solenoid actuated, preferably pilot operated inlet shutoff valve. The solenoid has a resilient elastomeric stop-ring for cushioning deceleration and limiting travel of the armature to prevent closing of the working air gap between the armature and a pole piece. The armature also has a cross port therethrough to alleviate flow-induced pressure decrease on the distal end of the armature from causing the armature to stick in the actuated position when the coil is de-energized.

Abstract: In an expansion valve of a refrigerant cycle, only by covering a diaphragm case and a part of a body case using a single vibration-proof member made of a rubber material, vibration in the diaphragm case can be effectively restricted. Because it is unnecessary to cover all surface of the expansion valve, the dimension of the vibration-proof member can be greatly reduced, and pipe connecting/removing operation in the expansion valve can be readily performed. Accordingly, a material cost of the vibration-proof member can be reduced, while noise caused due to the vibration of the expansion valve can be effectively reduced.

Abstract: The object of the present invention is to provide an expansion valve unit which prevents a temperature-sensing error from occurring due to transmission of a temperature lowered by the expansion of the refrigerant to a temperature-sensing chamber.

Abstract: A refrigerant cycle has a main expansion valve communicating with an inlet header which in turn communicates with a plurality of flow passages moving towards an evaporator coil. Each of the plurality of passages is provided with an individual restriction which provides additional expansion. The individual restrictions can each be separately controlled or designed such that the flow through each of the passages can be tailored to optimum efficiency and operation within the evaporator coil. However, the use of the main expansion valve in series with these restrictions ensures that each of the restrictions can be relatively simple items. Further, the use of the separate restrictions provides a system which has a simplified inlet header system.

Abstract: A hot water supply system wherein a flow of a refrigerant on a high-pressure side of a supercritical heat pump cycle and a flow of hot water are oppositely directed, and wherein water heated by the refrigerant on the high-pressure side is stored in heat insulating tanks of a vacuous and double structure. Water is heated with heat absorbed from the atmosphere and by the supercritical heat pump cycle having a high heat exchange efficiency &eegr;, to reduce the power required to heat the water. Therefore, hot water can be generated even in the daytime during peak power rates. Accordingly, because it is unnecessary to store hot water for daytime use in insulated tanks, system space requirements are reduced.

Abstract: A diagnostic system includes a controller adapted for coupling to a compressor or electronic stepper regulator valve. The controller produces a variable duty cycle control signal to adjust the capacity of the compressor or valve position of the electronic stepper regulator valve as a function of demand for cooling. The diagnostic system further includes a diagnostic module coupled to the controller for monitoring and comparing the duty cycle with at least one predetermined fault value indicative of a system fault condition and an alert module responsive to the diagnostic module for issuing an alert signal when the duty cycle bears a predetermined relationship to the fault value.