Abstract: In an ejector-type depressurizer, a nozzle arrangement converts pressure energy of refrigerant supplied from a radiator into velocity energy to depressurize and expand the refrigerant, and a pressurizer arrangement mixes the refrigerant discharged from the nozzle arrangement with the refrigerant drawn from an evaporator and converts the velocity energy of the refrigerant discharged from the nozzle arrangement into pressure energy to increase the pressure of the mixed refrigerant discharged from the pressurizer arrangement. The pressurizer arrangement includes a refrigerant passage that conducts the refrigerant supplied from the nozzle arrangement and the refrigerant supplied from the evaporator, and the refrigerant passage includes a refrigerant passing zone, through which the refrigerant from the nozzle arrangement and the refrigerant from the evaporator mainly pass during operation of the ejector-type depressurizer.

Abstract: A fluid in the state of two phase containing gas and liquid, which flows into the separating space, is revolved along an inner wall of the separating space and a liquid flow outlet is opened toward a revolving flow of the fluid and arranged in a lower portion of the separating space. The liquid-phase fluid which is a part of the revolving flow of the fluid flows out through the liquid flow outlet.

Abstract: In a liquid-level-position control device for a condenser in a Rankine cycle apparatus, first and second reference liquid level positions are set. When a position of the fluid level is lower than the first reference liquid level position, water is replenished to a condenser by a liquid-phase working medium supply section. When the position of the fluid level is higher than the second reference liquid level position, the liquid-phase working medium is discharged from within the condenser by a liquid-phase working medium discharge section. In this way, the liquid level, which is a boundary surface between water vapor and condensed water within the condenser, can be constantly kept at an optimal position.

Abstract: An ejector cycle device includes a gas-liquid separator for separating a refrigerant flowing out of an ejector into gas-phase refrigerant and liquid-phase refrigerant. The gas-liquid separator further separates refrigeration oil from the refrigerant. The refrigeration oil used by the ejector cycle device is less compatible to the refrigerant on the low-pressure side than the compatibility of the refrigeration oil with the refrigerant on a high-pressure side.

Abstract: An air-conditioner includes a compressor, a radiator, an evaporator, an ejector, and a separator. The compressor compresses refrigerant and variably controls an amount of the refrigerant. The radiator cools high-pressure refrigerant. The evaporator cools air blowing into a passenger compartment of a vehicle. The ejector having a nozzle jets the refrigerant at high speed. The separator separates the refrigerant into gas refrigerant and liquid refrigerant. An opening degree of a throttle of the nozzle in the ejector becomes larger so as to increase a cooling performance of the air-conditioner when the amount of the refrigerant discharged from the compressor is smaller than a maximum amount of the refrigerant.

Abstract: A cooling system for a vehicle has a refrigeration system with an ejector pump for ejecting fluid heated by a first heating element. The fluid is ejected at high speed to circulate the refrigerant and induce an entrainment effect. A radiator cools the refrigerant ejected from said ejector pump and an evaporator evaporates the refrigerant to generate refrigerating capacity. A first refrigerant circuit has a heat recovery circuit for exchanging heat between the first heating element and the refrigerant, ejecting the refrigerant and taking heat from the first heating element into the radiator via the heat recovery circuit with the use of the ejector pump, making the radiator dissipate the heat of the refrigerant, separating the refrigerant into gas-phase refrigerant and liquid-phase refrigerant by a gas-liquid separator, and making the gas-phase refrigerant return to the heat recovery circuit. A second refrigerant circuit decompresses the liquid-phase refrigerant.

Abstract: A vapor-compression refrigerant cycle system having an ejector includes a first evaporator for evaporating refrigerant from a pressure-increasing portion of the ejector, and a second evaporator for evaporating refrigerant to be drawn into a refrigerant suction port of the ejector. Furthermore, a valve member for opening and closing a refrigerant passage of the second evaporator is arranged in serious with the second evaporator in a refrigerant flow, and refrigerant flowing out of the second evaporator flows into the refrigerant suction port through a refrigerant suction pipe. The system is provided to restrict lubrication oil contained in refrigerant from being introduced from the ejector into and staying in the refrigerant suction pipe when the valve member is closed. For example, the refrigerant suction port is provided at an upper side of the ejector.

Abstract: In an ejector refrigerant cycle, even if refrigerant is super-heated in an evaporator, super-heated gas refrigerant does not directly flow into a gas-liquid separator, so that boiling of refrigerant does not occur in the gas-liquid separator due to evaporation of refrigerant in the gas-liquid separator. When an equivalent inner diameter (D) of a tank body of the gas-liquid separator is set in a range of 2 cm–6 cm, and when a ratio of a vertical dimension (H) of the tank body to the equivalent inner diameter (D) thereof is larger than 1, a wall thickness of the tank body can be reduced while gas-liquid separation performance in the gas-liquid separator can be improved.

Abstract: A turbomachinery system for cooling a high power density device includes a turbomachine configured to deliver a high flux cooling medium toward the high power density device, a housing containing a motor, a compressor, or both, of the turbomachine, a heat exchanger in fluid communication with the turbomachine and arranged for being thermally coupled to the high power density device, and a transition duct arranged intermediate the heat exchanger and turbomachine.

Abstract: In an ejector cycle with an ejector including a nozzle for decompressing refrigerant, an insulation member is provided on an outer surface of the ejector to suppress a heat exchange with an external side. When a suction portion of the ejector is insulated by the insulation member, pressure loss in the suction portion can be reduced, a gas refrigerant ratio at an inlet port of the mixing portion can be reduced, and a liquid refrigerant amount to be supplied to the evaporator can be increased. In addition, when a mixing portion and a diffuser portion of the ejector are insulated, it can prevent liquid refrigerant from being excessively evaporated. As a result, it can effectively restrict heat loss due to a heat exchange in the ejector with the external side.

Abstract: An ejector includes a nozzle having therein a throat portion, and a needle valve that extends at least from the throat portion to the outlet of the nozzle. The needle valve is displaced in an axial direction of the nozzle to adjust an opening degree of the throat portion and an opening degree of an outlet of the nozzle. Therefore, even when a flow amount of refrigerant flowing into the nozzle is changed, it can prevent a vertical shock wave from being generated by suitably adjusting both the opening degrees of the throat portion and the opening degree of the outlet of the nozzle. Accordingly, nozzle efficiency can be improved regardless of a change of the flow amount of the refrigerant.

Abstract: An air conditioning system for a vehicle has a cool storage heat exchanger for continuing cooling operation with stored cooling energy during a compressor is stopped due to a temporal stop of an engine for the vehicle. Cooling energy is stored in the cool storage material of the cool storage heat exchanger during a normal cooling operation during which the compressor is operated by the engine. When the vehicle stops, for example before a traffic lamp, and thereby the compressor is not operated, an ejector is operated to circulate the refrigerant from the cool storage heat exchanger to an evaporator so that the cooling operation can be continued.

Abstract: In a vapor-compression refrigerant cycle system, a switching device is provided to switch one of a first mode where high-pressure refrigerant discharged from a compressor is directly introduced to an exterior heat exchanger and a second mode where the high-pressure refrigerant is directly introduced to an interior heat exchanger. When the second mode is set, the pressure of the high-pressure refrigerant is set higher than a predetermined pressure by a constant-pressure control valve. Accordingly, it can prevent heating capacity of the interior heat exchanger from being greatly changed even when thermal load of the vapor-compression refrigerant cycle system is changed, and heating capacity of the interior heat exchanger can be improved in the second mode.

Abstract: When an air conditioning heat load is equal to or greater than a predetermined value, the degree of throttle opening of a nozzle arrangement of an ejector is controlled in such a manner that a coefficient of performance coincides with a target value. When the air conditioning heat load is less than the predetermined value, the degree of throttle opening of the nozzle arrangement is controlled in such a manner that a flow rate of refrigerant, which passes through the nozzle arrangement, coincides with a target value.

Abstract: An air conditioner includes a compressor for compressing refrigerant, an exterior heat exchanger for performing heat exchange between refrigerant and outside air, an interior heat exchanger for performing heat exchange between the refrigerant and air to be blown into the compartment, an ejector for decompressing high-pressure refrigerant, a heater core for heating air using a high-temperature fluid as a heating source, and a fluid-refrigerant heat exchanger that heats the fluid flowing to the heater core using high-temperature refrigerant discharged from the compressor as a heating source. In a dehumidifying and heating operation, refrigerant in the interior heat exchanger absorbs heat from air so that the air is cooled and dehumidified, and the dehumidified and cooled air can be further heated in the heater core by indirectly using the heating source from the high-temperature refrigerant.

Abstract: An ejector decompression device for a refrigerant cycle includes a nozzle which decompresses refrigerant flowing out of a refrigerant radiator, and a pressure increasing portion which increases a pressure of refrigerant while refrigerant jetted from the nozzle and refrigerant drawn from an evaporator are mixed. In the ejector cycle, a coaxial degree of the nozzle with respect to the pressure increasing portion is in a range between 0-30% of an inlet diameter of the pressure increasing portion. Alternatively, the pressure increasing portion has a taper portion at least in a predetermined range from the inlet of the pressure increasing portion, and the taper portion is provided to increase a passage sectional area from the inlet of the pressure increasing portion. Accordingly, collision of high-speed refrigerant jetted from the nozzle to an inner wall surface of the pressure increasing portion can be restricted.

Abstract: A method of, and apparatus, for, controlling the temperature of pressurized air such as bleed air from a gas turbine engine, wherein the air is passed through a heat exchanger to exchange heat with coolant air which is caused to flow through the heat exchanger by operation of an ejector device powered by some of the pressurized air, the supply of the pressurized air to the ejector device is controlled to control the flow of coolant air and hence control the temperature of the pressurized air downstream of the heat exchanger.

Abstract: In an ejector cycle with an ejector including a nozzle for decompressing refrigerant, a refrigerant outlet is provided in an evaporator at a position upper than a refrigerant inlet. Therefore, a circulation performance of refrigerant flowing in the evaporator can be improved. Accordingly, even when a pumping capacity generated in the ejector becomes smaller, a sufficient amount of refrigerant can be drawn into the ejector from the evaporator. Thus, a refrigerant amount supplied to the evaporator can be effectively increased. Further, a control unit controls an amount of cooling air supplied to a condenser based on the temperature of the cooling air, to control a refrigerant state to be introduced to the nozzle. In this case, a pressure increasing amount in the ejector can be effectively increased, and consumption power in the compressor can be effectively increased.

Abstract: In an ejector, a nozzle is provided within a housing to defining a passage portion around the nozzle, and a suction port is provided in the housing to draw a refrigerant by entrainment of a driving refrigerant jetted from the nozzle. Further, a wall portion is provided in the housing such that the refrigerant drawn from the suction port into the passage portion is prevented from flowing toward an inlet side of the nozzle from a position of the suction port in an axial direction of the nozzle. Therefore, all of the refrigerant flowing from the suction port flows toward an outlet side of the nozzle without flowing toward the inlet side of the nozzle from the position of the suction port in the axial direction. Thus, it can prevent a large pressure loss from being caused in the refrigerant sucked from the suction port, and ejector efficiency can be effectively increased.

Abstract: In an ejector cycle having an ejector, a decompression amount of refrigerant between a gas-liquid separator and an evaporator is adjusted by a differential pressure control valve, so that a pressure increasing amount in a pressure increasing portion of the ejector is controlled to be equal to or lower than a predetermined amount. Therefore, a suction pressure of refrigerant to be sucked to the compressor can be restricted from being excessively increased in accordance with the increase of the pressure increasing amount in the ejector, and it can prevent heat radiating capacity of a radiator from being decreased. Thus, a sufficient cooling capacity can be always obtained in the ejector cycle.

Abstract: In an ejector-type depressurizer, a nozzle arrangement converts pressure energy of refrigerant supplied from a radiator into velocity energy to depressurize and expand the refrigerant, and a pressurizer arrangement mixes the refrigerant discharged from the nozzle arrangement with the refrigerant drawn from an evaporator and converts the velocity energy of the refrigerant discharged from the nozzle arrangement into pressure energy to increase the pressure of the mixed refrigerant discharged from the pressurizer arrangement. The pressurizer arrangement includes a refrigerant passage that conducts the refrigerant supplied from the nozzle arrangement and the refrigerant supplied from the evaporator, and the refrigerant passage includes a refrigerant passing zone, through which the refrigerant from the nozzle arrangement and the refrigerant from the evaporator mainly pass during operation of the ejector-type depressurizer.

Abstract: In a refrigerating cycle, a heat radiation of a gas cooler is reduced by a heat radiation reduction member when one of a pressure and a temperature of a high pressure side refrigerant is equal to or less than a predetermined value. When a discharge pressure of the refrigerant discharged from a compressor is equal to or lower than the predetermined level, the heat radiation of the gas cooler is reduced by the heat radiation reduction member. Thus, the refrigerant pressure of the high pressure side is increased while the refrigerant pressure of a low pressure side is decreased. With this, a flow rate at a high pressure inlet of an ejector is increased. Also, a flow rate at a low pressure inlet of the ejector is increased. Accordingly, a temperature of air blown from an evaporator is decreased without frosting the evaporator even when a load of the cycle is low.

Abstract: In an ejector cycle with an ejector including a nozzle for decompressing refrigerant, a variable throttle device is disposed upstream from the nozzle to decompress and expand high-pressure refrigerant flowing from a condenser. For example, the variable throttle device decompresses the high-pressure refrigerant in a gas-liquid two-phase state at an upstream position from the nozzle of the ejector. In addition, the variable throttle device includes a back pressure chamber having an inner pressure that changes by sensing a refrigerant temperature at a refrigerant outlet side of an evaporator, and a pressure introducing means for introducing a refrigerant pressure of a refrigerant outlet side of the evaporator to a side opposite to the back pressure chamber with respect to a diaphragm. Therefore, a pressure difference between the back pressure chamber and the side opposite to the back pressure chamber can be made smaller.

Abstract: In an ejector cycle with an ejector including a nozzle for decompressing refrigerant, a variable throttle is disposed upstream from the nozzle of the ejector to decompress and expand high-pressure refrigerant flowing from a radiator. For example, the variable throttle decompresses and expands the high-pressure refrigerant in a gas-liquid two-phase state at an upstream position from the nozzle of the ejector. The variable throttle controls a throttle opening degree so that a refrigerant super-heating degree at a refrigerant outlet side of an evaporator or at a refrigerant suction side of a compressor becomes in a predetermined range. Accordingly, the ejector cycle has an improved nozzle efficiency and an improved ejector efficiency in a wide load variation range of the ejector cycle.

Abstract: In a hot gas heating mode of an ejector cycle system, hot gas refrigerant discharged from a compressor is introduced to an interior heat exchanger while bypassing an exterior heat exchanger. The refrigerant discharged from the interior heat exchanger can flow into an ejector from at least an inlet of a nozzle of the ejector, and flows into the gas-liquid separator, in the heating mode. Alternatively, refrigerant discharged from the compressor can be supplied to the interior heat exchanger through a clearance between an outer wall of the nozzle and an inner wall of a nozzle housing portion, while bypassing the exterior heat exchanger in the heating mode. Here, the nozzle is disposed in the nozzle housing portion, and a part of pressurizing portion is defined by the nozzle housing portion. Thus, the heating mode can be readily performed in the ejector cycle system.

Abstract: In a vapor-compression refrigerant cycle having an ejector, a mixture refrigerant of a first refrigerant and a second refrigerant is used. When the mixture refrigerant is decompressed and expanded in a nozzle of the ejector, the first refrigerant has an adiabatic heat drop that is larger than that of the second refrigerant. Further, the second refrigerant has an evaporation latent heat that is larger than that of the first refrigerant. In a gas-liquid separator, a gas-phase amount of the first refrigerant is made larger than that of the second refrigerant, and a liquid-phase amount of the second refrigerant is made larger than that of the first refrigerant. For example, the first refrigerant is propane, and the second refrigerant is butane. Accordingly, expansion energy recovered in the nozzle can be effectively converted to pressure energy in a pressure increasing portion of the ejector while cooling capacity of an evaporator can be improved.

Abstract: A vapor-compression refrigerant cycle system includes a first evaporator in which refrigerant is evaporated, a second evaporator in which refrigerant is evaporated at a pressure lower than that in the first evaporator, and a switching device for switching between a first circulation where the refrigerant is circulated to the first evaporator and a second circulation where the refrigerant is circulated to the second evaporator. When the switching device switches to the second circulation from the first circulation, a refrigerant circulation into the second evaporator is stopped until the refrigerant pressure in the second evaporator becomes equal to or lower than a predetermined pressure. Therefore, the pressure in the second evaporator can be rapidly reduced. Further, when carbon dioxide is used as the refrigerant, the pressure in the second evaporator can be further rapidly reduced.

Abstract: In a refrigerant cycle with an ejector, there is provided with a bypass passage through which a part of high-pressure refrigerant from a radiator flows into a low-pressure refrigerant passage between an evaporator and a suction port of the ejector while bypassing a nozzle of the ejector. Further, a control valve is disposed to open the bypass passage so that refrigerant flows through the bypass passage when the pressure of the high-pressure refrigerant becomes in a predetermined condition. Accordingly, it can prevent the pressure of the high-pressure refrigerant from being excessively increased due to increase of a refrigerant flow amount. Therefore, the refrigerant cycle operates stably.

Abstract: In an ejector cycle with an ejector including a nozzle for decompressing refrigerant, a control unit controls an air blowing amount of an evaporator fan so that a flow speed of refrigerant flowing in an evaporator becomes in a predetermined flow speed range. Therefore, it can prevent a large amount of lubrication oil from staying in the evaporator, and thereby the lubrication oil can sufficiently returns to a compressor. For example, the control unit includes a determining means for determining the predetermined flow speed range based on at least one of an atmosphere temperature of a condenser, a temperature of air supplied to the evaporator and a flow amount of refrigerant discharged from the compressor.

Abstract: Apparatus for cooling a fuel cell stack. The cooling system uses vaporization cooling of the fuel stack and supersonic vapor compression of the vaporized coolant to significantly increase the temperature and pressure of the liquid coolant flowing through a heat exchanger. By increasing the heat rejection temperature of the coolant delivered to the heat exchanger, the heat transfer area of the heat exchanger can be reduced and the mass flow rate of coolant can also be reduced. The increased fluid pressure is used to circulate the coolant through the cooling system, thereby eliminating the circulation pump associated with conventional systems.

Abstract: In an ejector cycle having an ejector for decompressing refrigerant, a check valve is disposed in an oil return passage through which refrigerant including a lubrication oil is introduced from a refrigerant outlet side of an evaporator to a refrigerant suction side of a compressor while bypassing the ejector. When the lubrication oil amount staying in the evaporator reduces, the check valve is automatically closed, and a normal operation mode of the ejector cycle is automatically set. On the contrary, when a large amount of lubrication oil stays in the evaporator, the check valve is automatically opened, and an oil return mode is automatically set. Therefore, the lubrication oil staying in the evaporator can be controlled equal to or lower than a predetermined amount, thereby effectively returning the lubrication oil to the compressor.

Abstract: In a vapor-compression refrigerant cycle system, a switching device is provided to switch one of a first mode where high-pressure refrigerant discharged from a compressor is directly introduced to an exterior heat exchanger and a second mode where the high-pressure refrigerant is directly introduced to an interior heat exchanger. When the second mode is set, the pressure of the high-pressure refrigerant is set higher than a predetermined pressure by a constant-pressure control valve. Accordingly, it can prevent heating capacity of the interior heat exchanger from being greatly changed even when thermal load of the vapor-compression refrigerant cycle system is changed, and heating capacity of the interior heat exchanger can be improved in the second mode.

Abstract: In an ejector cycle with an ejector including a nozzle for decompressing refrigerant, a refrigerant outlet is provided in an evaporator at a position upper than a refrigerant inlet. Therefore, a circulation performance of refrigerant flowing in the evaporator can be improved. Accordingly, even when a pumping capacity generated in the ejector becomes smaller, a sufficient amount of refrigerant can be drawn into the ejector from the evaporator. Thus, a refrigerant amount supplied to the evaporator can be effectively increased. Further, a control unit controls an amount of cooling air supplied to a condenser based on the temperature of the cooling air, to control a refrigerant state to be introduced to the nozzle. In this case, a pressure increasing amount in the ejector can be effectively increased, and consumption power in the compressor can be effectively increased.

Abstract: In an ejector cycle with an ejector including a nozzle for decompressing refrigerant, a receiver for storing refrigerant therein is disposed at a refrigerant outlet side of a condenser. Further, a bypass passage and a switching valve for opening and closing the bypass passage are provided so that high-temperature refrigerant discharged from a compressor is introduced into an evaporator while bypassing the condenser in a defrosting operation. When the defrosting operation is set, the switching valve is opened while a fan for blowing cool air to the condenser is operated. Accordingly, in the defrosting operation, at least a part of refrigerant discharged from the compressor flows into the evaporator to remove frost on a surface of the evaporator, and a surplus refrigerant is condensed in the condenser and is stored in the receiver. Accordingly, it can prevent condensation capacity of the condenser from being decreased.

Abstract: In an ejector cycle with an ejector including a nozzle for decompressing refrigerant, a variable throttle device is disposed upstream from the nozzle to decompress and expand high-pressure refrigerant flowing from a condenser. For example, the variable throttle device decompresses the high-pressure refrigerant in a gas-liquid two-phase state at an upstream position from the nozzle of the ejector. In addition, the variable throttle device includes a back pressure chamber having an inner pressure that changes by sensing a refrigerant temperature at a refrigerant outlet side of an evaporator, and a pressure introducing means for introducing a refrigerant pressure of a refrigerant outlet side of the evaporator to a side opposite to the back pressure chamber with respect to a diaphragm. Therefore, a pressure difference between the back pressure chamber and the side opposite to the back pressure chamber can be made smaller.

Abstract: In a refrigerating cycle, a heat radiation of a gas cooler is reduced by a heat radiation reduction member when one of a pressure and a temperature of a high pressure side refrigerant is equal to or less than a predetermined value. When a discharge pressure of the refrigerant discharged from a compressor is equal to or lower than the predetermined level, the heat radiation of the gas cooler is reduced by the heat radiation reduction member. Thus, the refrigerant pressure of the high pressure side is increased while the refrigerant pressure of a low pressure side is decreased. With this, a flow rate at a high pressure inlet of an ejector is increased. Also, a flow rate at a low pressure inlet of the ejector is increased. Accordingly, a temperature of air blown from an evaporator is decreased without frosting the evaporator even when a load of the cycle is low.

Abstract: In an ejector cycle having an ejector, a throttle is provided inside a passenger compartment adjacent to an evaporator so that a length of a refrigerant passage between the throttle and the evaporator is shortened. Therefore, it can restrict a part of liquid refrigerant after being decompressed in the throttle from being evaporated in the refrigerant passage, before being introduced into the evaporator. In addition, a refrigerant inlet is provided at a lower header tank of an evaporator. Therefore, a gas-liquid refrigerant distribution difference due to the density difference between gas refrigerant and liquid refrigerant can be effectively restricted. Thus, refrigerant distributed into the plural tubes from the lower header tank can be made uniform, even if the refrigerant flow speed is low in the ejector cycle.

Abstract: In an ejector cycle with an ejector including a nozzle for decompressing refrigerant, an insulation member is provided on an outer surface of the ejector to suppress a heat exchange with an external side. When a suction portion of the ejector is insulated by the insulation member, pressure loss in the suction portion can be reduced, a gas refrigerant ratio at an inlet port of the mixing portion can be reduced, and a liquid refrigerant amount to be supplied to the evaporator can be increased. In addition, when a mixing portion and a diffuser portion of the ejector are insulated, it can prevent liquid refrigerant from being excessively evaporated. As a result, it can effectively restrict heat loss due to a heat exchange in the ejector with the external side.

Abstract: A gas-liquid separator (accumulator) is arranged at a refrigerant suction side of a compressor of a refrigerant cycle system mounted in a vehicle. The gas-liquid separator includes a gas-liquid separation portion for separating refrigerant into gas refrigerant and liquid refrigerant, and a liquid refrigerant storage portion for storing therein the separated liquid refrigerant. In the gas-liquid separator, the gas-liquid separation portion is arranged approximately vertically, and the liquid refrigerant storage portion is arranged approximately horizontally with respect to the approximately vertically arranged gas-liquid separation portion. Therefore, mounting performance of the gas-liquid separator in the vehicle can be effectively improved while gas-liquid separation can be accurately performed.

Abstract: In a vapor compression refrigerant cycle using refrigerant having a critical temperature equal to or less than sixty degrees Celsius, when refrigerant temperature detected by a sensor as a parameter of a low-pressure side refrigerant pressure is higher than a saturation temperature corresponding to a predetermined pressure that is equal to or less than a critical pressure, a volume of air passing through an evaporator is controlled smaller than a predetermined volume by controlling operation of a blower unit. Because heat exchange rate (heat absorbing rate) in the evaporator is controlled, the pressure of the low-pressure side refrigerant is maintained below the critical pressure. Alternatively, the heat exchange rate is controlled by reducing a flow rate of the refrigerant in the evaporator.

Abstract: A turbomachinery system for cooling a high power density device includes a turbomachine configured to deliver a high flux cooling medium toward the high power density device, a housing containing a motor, a compressor, or both, of the turbomachine, a heat exchanger in fluid communication with the turbomachine and arranged for being thermally coupled to the high power density device, and a transition duct arranged intermediate the heat exchanger and turbomachine.

Abstract: In an ejector cycle having an ejector, a decompression amount of refrigerant between a gas-liquid separator and an evaporator is adjusted by a differential pressure control valve, so that a pressure increasing amount in a pressure increasing portion of the ejector is controlled to be equal to or lower than a predetermined amount. Therefore, a suction pressure of refrigerant to be sucked to the compressor can be restricted from being excessively increased in accordance with the increase of the pressure increasing amount in the ejector, and it can prevent heat radiating capacity of a radiator from being decreased. Thus, a sufficient cooling capacity can be always obtained in the ejector cycle.

Abstract: In a vapor compression refrigerant cycle for an air conditioner, as a refrigerant pressure at an operation starting time of a compressor increases, a starting target rotational speed of the compressor is reduced, and the operation of the compressor is started by the reduced starting target rotational speed. Accordingly, when the operation of the compressor is started, it can prevent the pressure of high-pressure side refrigerant from exceeding an allowable pressure of the compressor, thereby preventing a safety device of the compressor from operating. Therefore, even when the operation of the compressor is started in a high load state, a pressure abnormality is not generated in the refrigerant cycle, and operation of the air conditioner can be prevented from being stopped.

Abstract: In an ejector, a nozzle is provided within a housing to defining a passage portion around the nozzle, and a suction port is provided in the housing to draw a refrigerant by entrainment of a driving refrigerant jetted from the nozzle. Further, a wall portion is provided in the housing such that the refrigerant drawn from the suction port into the passage portion is prevented from flowing toward an inlet side of the nozzle from a position of the suction port in an axial direction of the nozzle. Therefore, all of the refrigerant flowing from the suction port flows toward an outlet side of the nozzle without flowing toward the inlet side of the nozzle from the position of the suction port in the axial direction. Thus, it can prevent a large pressure loss from being caused in the refrigerant sucked from the suction port, and ejector efficiency can be effectively increased.

Abstract: In a vapor compression refrigeration system, an evaporator and a gas-liquid separator are received in a common casing, so that the gas-liquid separator and the evaporator are placed close to each other. Thus, it is possible to limit heat absorption of the liquid phase refrigerant from the atmosphere to reduce the heat loss upon discharge of the refrigerant from the gas-liquid separator. Also, it is possible to reduce pressure loss in a refrigerant passage between the gas-liquid separator and the evaporator.

Abstract: In an ejector, a nozzle includes a nozzle tapered section having an inner passage with a radial dimension reduced toward a nozzle outlet port, and a needle having a needle tapered section disposed in the inner passage. The needle tapered section has a cross sectional area reduced toward a downstream end of the needle, and the downstream end of the needle is positioned at a downstream side with respect to the nozzle outlet port. In addition, the nozzle tapered section has a taper angle (&phgr;1) which is equal to or greater than a taper angle (&phgr;2) of the needle tapered section. Therefore, a boundary face on the outside of a nozzle jet flow becomes in a balanced natural shape, and is controlled in accordance with an operating condition. Thus, the ejector cycle can be operated while keeping high efficiency, regardless of the thermal load of the ejector cycle.

Abstract: A refrigerant cycle includes an ejector having a throttle changeable nozzle. In the refrigerant cycle, a control valve having a needle valve controls a pressure of a middle-pressure refrigerant in a bypass passage, and a pilot valve controls a throttle opening degree of the nozzle in accordance with a pressure difference between the pressure of the middle-pressure refrigerant in the bypass passage and the refrigerant pressure in a high-pressure refrigerant inlet port of the ejector. When an opening degree of the needle valve is changed in accordance with a load variation or a load state, the pressure of the middle-pressure refrigerant in the bypass passage is changed. Accordingly, the moving position of the pilot valve is controlled, and the throttle opening degree of the nozzle is controlled.

Abstract: An ejector includes a nozzle and a needle valve formed in a tapered shape. The needle valve controls a throttle opening degree of the nozzle from a minimum degree to a maximum degree while an end section of the needle valve is positioned on a downstream side with respect to a throat section of the nozzle. Besides, a cross-sectional area of a nozzle diffuser is formed to be substantially constant, downstream of the throat section. Thus, a cross-sectional area of a substantial refrigerant passage defined by an inner surface of the nozzle and the needle valve is gradually widened in accordance with the tapered shape of the needle valve. Therefore, pressure loss accompanied with a rapid expanding can be suppressed. As a result, the throttle opening degree of the nozzle can be controlled while improving nozzle efficiency and ejector efficiency.

Abstract: In a vapor-compression refrigerant cycle having an ejector, a mixture refrigerant of a first refrigerant and a second refrigerant is used. When the mixture refrigerant is decompressed and expanded in a nozzle of the ejector, the first refrigerant has an adiabatic heat drop that is larger than that of the second refrigerant. Further, the second refrigerant has an evaporation latent heat that is larger than that of the first refrigerant. In a gas-liquid separator, a gas-phase amount of the first refrigerant is made larger than that of the second refrigerant, and a liquid-phase amount of the second refrigerant is made larger than that of the first refrigerant. For example, the first refrigerant is propane, and the second refrigerant is butane. Accordingly, expansion energy recovered in the nozzle can be effectively converted to pressure energy in a pressure increasing portion of the ejector while cooling capacity of an evaporator can be improved.

Abstract: A method of, and apparatus, for, controlling the temperature of pressurized air such as bleed air from a gas turbine engine, wherein the air is passed through a heat exchanger to exchange heat with coolant air which is caused to flow through the heat exchanger by operation of an ejector device powered by some of the pressurized air, the supply of the pressurized air to the ejector device is controlled to control the flow of coolant air and hence control the temperature of the pressurized air downstream of the heat exchanger.