Abstract: The present invention provides an energy storage device that utilizes a cold sink that undergoes cycles of freezing and thawing. The device converts electrical energy to stored thermal energy, and then re-converts the stored thermal energy to electrical energy, as needed or desired. The device can store energy on a large scale (e.g., on the order of megawatts or greater) and for an extended period of time (e.g., for at least 12 hours, or longer, as needed).

Abstract: A heating and cooling system for inlet air of a turbine compressor. The heating and cooling system may include a fluid coil positioned about the turbine compressor and a thermal energy storage tank. The fluid coil and the thermal energy storage tank are in fluid communication such that fluid is both provided to the fluid coil from the thermal energy storage tank for exchanging heat with the inlet air and returned to the thermal energy storage tank without further heat exchange.

Abstract: An air conditioning system is provided with mainly an evaporator, a compressor, a condenser and an energy recovery device. The compressor is fluidly connected to the evaporator to compress low-pressure refrigerant exiting the evaporator to high-pressure refrigerant. The condenser is fluidly connected to the compressor to receive the high pressure refrigerant and dissipate heat therefrom. The energy recovery device is configured to extract work from refrigerant flowing therethrough. The energy recovery device includes a movable expander and a valve. The movable expander has an inlet fluidly connected to the condenser to receive high pressure refrigerant exiting the condenser, an outlet fluidly connected to the evaporator to deliver low pressure refrigerant thereto and a chamber fluidly connected between the inlet and the outlet. The valve is configured to control a flow rate of high pressure refrigerant flowing from the inlet to the chamber.

Abstract: An aircraft air provision system includes a power turbine that receives bleed air at a first pressure and provides rotational energy to a shaft and outputs output air at an intermediate pressure. The system also includes a compressor coupled to the shaft that receives input air at a second pressure that is lower than the first pressure and outputs compressed air having a pressure equal to the intermediate pressure and a mix chamber coupled to outputs of both the power turbine and the compressor where the output air and the compressed air are mixed. The system also includes a cooling turbine coupled to the shaft and that is in fluid communication with an output of the mix chamber.

Abstract: An air cycle machine includes two turbines and a compressor mounted on an integral shaft. The integral shaft includes a plurality of shaft sections that are welded together and machined in a single set-up process into a desired shaft shape to provide highly aligned bearing surfaces. The shaft includes three stops that cooperate with three fasteners to secure the two turbines and the compressor on the shaft.

Abstract: There may be a case where, by simply coupling the first compressor (expander compressor unit) and the second compressor with an oil-equalizing pipe, the first compressor is not lubricated sufficiently, thereby decreasing reliability. The volumetric capacity (V1) of the first available oil space (130) of the first compressor (101) is set larger than the volumetric capacity (V2) of the second available oil space (140) of the second compressor (102). With this configuration, even if the oil level (S1) of the first oil sump (13) decreases in transition to a state of steady operation, it is possible to maintain a sufficient amount of oil in the first compressor (101), and thus high reliability as a fluid machine can be achieved.

Abstract: An environmental control system (ECS) includes an air cycle machine with an expansion turbine and a condenser having a cold air inlet connected to receive air from the expansion turbine. The condenser has hollow, internally finned hot bars positioned at the cold air inlet to prevent ice formation at the cold air inlet.

Abstract: This invention relates to an aircraft air conditioning system with at least one compressor, a first conduit connected with a pressure side of the compressor and at least one cooling unit provided downstream of the compressor. A second bypass conduit is connected with the pressure side of the compressor to conduct at least part of the compressed air around at least one cooling unit and has a throttle for varying air flow therethrough.

Abstract: A refrigerant system incorporates an expander. At least a portion of refrigerant bypasses an evaporator and is injected into the compression process to cool main refrigerant vapor flow and compressor elements. In disclosed embodiments, the injected refrigerant may be partially expanded in the expander and routed either into the compressor suction or to an intermediate point in the compression process. A valve may control the amount of the injected refrigerant to achieve desired operational characteristics for the refrigerant system.

Abstract: An air cycle refrigerating/cooling system includes a first heat exchanger for cooling air, a turbine unit that has a compressor for compressing the air and an expansion turbine for adiabatically expanding the air, and a second heat exchanger for cooling the air. A compressor rotor of the compressor and a turbine rotor of the expansion turbine are attached to a common main shaft in the turbine unit in such a manner that the turbine unit drives the compressor rotor with a power generated by the turbine rotor, and the main shaft is rotatably supported by a rolling contact bearing. A part or the entirety of a thrust force applied to the main shaft is supported by an electromagnet, and a pressure equalizing device for equalizing a gas pressure at opposite ends of the rolling contact bearing is provided.

Abstract: An ECS system provides an ACM which locates the compressor upon a common shaft between a first turbine and a second turbine. Each RAF is located remote from the ACM such that the turbines are located outboard on each end of the ACM to provide the highest efficiency possible with each turbine using a straight axial outlet diffuser. As the compressor is located between the turbines the bypass circuits from the turbines are less circuitous and more efficient. Integral valve ports formed into the ACM housing portions results in a weight reduced design due to increase bypass efficiencies and simplified installations.

Abstract: The air conditioning system uses an air cycle thermodynamic process. The system comprises a centrifuge. This centrifuge includes at one of its ends, an axial inlet that funnels air into a centrifugal compressor rotating in unison with the centrifuge. The air is compressed, adiabatically heated and directed to a heat exchanger mounted in the rim of, and rotating with the centrifuge. The air is accelerated with respect the centrifuge by varying the centrifuge radius or by using forward leaning impeller blades. The air is cooled by the heat exchanger and directed to an expander also rotating with the centrifuge. The air is expanded and adiabatically further cooled. The cold air exits the centrifuge through an axial outlet located at the second end of the centrifuge.

Abstract: The air cycle refrigerating/cooling system compresses air that has flown in with a compressor (6) in a turbine unit (5) and adiabatically expands the air with an expansion turbine (7) in a turbine unit (5). In the turbine unit (5), a compressor rotor (6a) of the compressor (6) and a turbine rotor (7a) of the expansion turbine (7) are attached to the same main shaft (13), the main shaft (13) is supported by bearings (15) and (16) so as to be freely rotatable, and part or the entirety of the thrust force applied to this main shaft (13) is supported by an electromagnet (17).

Abstract: The turbine outlet heated diffuser may include a cavity positioned immediately downstream of an air cycle machine turbine. The turbine outlet heated diffuser may be designed to prevent or reduce ice formation at the turbine outlet by heating the diffuser wall. The cavity may receive a heated flow from an air cycle machine compressor discharge and provide a cavity outlet flow to a turbine inlet plenum. The design of the heated diffuser is such to minimize the cycle performance impact that results from the addition of an air cycle machine icing protection feature.

Abstract: Method for converting thermal energy at a low temperature into thermal energy at a relatively high temperature by means of mechanical energy, and vice versa, with a working medium which runs through a closed thermodynamic circulation process, wherein the circulation process has the following working steps: —reversible adiabatic compression of the working medium, —isobaric conduction away of heat from the working medium, —reversible adiabatic relaxing of the working medium, —isobaric supply of heat to the working medium, and wherein the increase or decrease in pressure of the working medium is produced during the compression or relaxing, increasing or decreasing the centrifugal force acting on the working medium, with the result that the flow energy of the working medium is essentially retained during the compression or relaxing process.

Abstract: An environmental control system (ECS) for providing conditioned air to a cabin of an aircraft at a desired rate may include a bleed-air driven primary air treatment unit configured to produce pack supply air and to recirculate a portion of the pack supply air into a compressor of the primary air treatment unit. The ECS may also include a bleed-air driven secondary air treatment unit configured to compress ram air at a rate that corresponds to the rate of recirculation. The ECS may be configured to selectively deliver conditioned air from both the primary and the secondary air treatment units to the cabin.

Abstract: An energy efficient air conditioning system preferably includes a compressor, a reaction turbine, an electrical generator, an expansion device, an evaporator coil, an evaporator fan and a refrigerant gas. A condenser coil and fan are replaced with the reaction turbine. Hot high pressurized gas is piped into the reaction turbine from the compressor, which causes a drive shaft of the reaction turbine to spin the electrical generator. High pressurized liquid exits the reaction turbine into the expansion device as a high pressure liquid. A low pressure liquid exists at an output of the expansion device and enters the evaporator coil. The low pressure liquid boils, absorbing heat in the evaporator. The evaporator fan blows warm air from a confined space over the evaporator coil to provide a flow of cold air to the confined space. The low pressure gas then enters the compressor to start a new cycle.

Abstract: A method for managing heat in an airplane includes extracting hot bleed air from a gas turbine engine, and cooling the hot bleed air in a first heat exchanger thereby forming warm bleed air. The method further includes expanding the warm bleed air with a turbine thereby forming cool bleed air, and using the cool bleed air as a heat sink in a second heat exchanger associated with an environmental control system and thereby forming used bleed air.

Abstract: The present invention provides a technique for rapidly removing frost accumulated in air-refrigerant cooling apparatuses. An air-refrigerant cooling apparatus in accordance with the present invention includes a bypass line for directly supplying a defroster with refrigerant air having an increased temperature from a compressor, avoiding temperature drop by a heat exchanger and an expansion turbine. Moisture of the frost melted in the defroster is externally exhausted by a fan.

Abstract: A solar powered air conditioner comprising of at least one solar panel, an inverter that converts the DC voltage created by the solar panels to AC voltage connected to the solar panel, a battery charger that receives the AC voltage from the inverter and converts the AC voltage to DC voltage, a charge controller connected to the battery charger, a rechargeable battery connected to the charge controller, a contactor connected to the rechargeable battery and to a thermostat, a DC powered motor connected to the contactor, and an air conditioning system, the air conditioning system having an air compressor and an air conditioning motor, the air compressor connects to the DC powered motor via a belt, and the air conditioner motor connects to the contactor.

Abstract: An improved multi-stage compressor device for compressing gas, which compressor device (1) mainly consists of at least two compressor elements (2-5-28) placed in series one after the other, at least one of which (5-28) is driven by a motor (9), characterized in that at least one other compressor element (2) is driven separately, in other words without any mechanical link with said motor (9), by means of an expander (18) of a closed power cycle (12) with a circulating medium inside which is heated by the compressed gas.

Abstract: In a heat exchanger unit for conditioning a first fluid, particularly a refrigerant in an air conditioning system, including a heat exchanger, the heat exchanger includes first and second tube element units for heat exchange between a first fluid flowing through the tube elements and a second fluid flowing over the tube elements, wherein the first fluid is supplied first to the first tube element unit so as to flow upwardly therethrough and via an intermediate outlet connector to a compressor stage from where it is transferred to the top of the second tube element unit which is disposed above the first tube element unit and flows downwardly through the second tube element unit to an expansion stage wherein the energy released during expansion in the expansion stage is utilized for the compression of the first fluid in the compressor stage.

Abstract: A high efficiency, low maintenance single stage or multi-stage centrifugal compressor assembly for large cooling installations. The assembly is highly efficient by virtue of a variable frequency drive (VFD) that drives a permanent magnet motor and matches compressor speed with compressor load, a direct drive impeller that eliminates gearing losses, and magnetic bearings that reduce frictional losses. The back-emf produced by the motor provides an intermediate power source for the magnetic bearings in the event of a loss of electrical power. A cooling system provides direct cooling of the rotor with gas refrigerant, and cooling of the stator with liquid refrigerant. Modular construction allows the compressor to be retrofit with upgrades. An inlet guide vane system operates without need for oil lubrication. The use of light metal castings and elimination of gearing reduces the weight to one-third or less of comparably powered conventional units.

Abstract: A fluid machine includes a casing, a compression mechanism for compressing refrigerant, an expansion mechanism for expanding refrigerant, and a rotary shaft connecting the compression mechanism and the expansion mechanism. The compression mechanism, the expansion mechanism and the rotary shaft are disposed in the casing. A heat insulator partitions an internal space of the casing into a first space with the expansion mechanism disposed therein and a second space with the compression mechanism disposed therein. The rotary shaft passes through the heat insulator. An elastically deformable seal element seals a clearance between an outer periphery of the heat insulator and an inner periphery of the casing.

Abstract: A refrigeration system for minimizing the cool down time of a mass to cryogenic temperatures including a compressor, an expander, a gas storage tank, interconnecting gas lines, and a control system. The compressor output is maintained near its maximum capability by maintaining near constant high and low pressures during cool down, gas being added or removed from the storage tank to maintain a near constant high pressure, and the speed of said expander being adjusted to maintain a near constant low pressure, no gas by-passing between high and low pressures.

Abstract: The vapor compression refrigerating apparatus of the invention comprises a compressor 2, a condenser 4, a regeneration heat exchanger 6, an expansion means 8, and an evaporator 10 connected in series. The vapor compression refrigerating cycle is based on a cycle corresponding to a reversed Ericsson cycle in which isothermal heat dissipation process and isothermal heat absorption process occur overstriding a saturated vapor line and saturated liquid line respectively and heat exchange is carried out between isobaric heat dissipation process in a liquid zone and isobaric heat absorption process in a superheated vapor zone.

Abstract: The purpose present invention is to provide an air refrigerant type cooling apparatus provided with an internal air cooling mechanism with high reliability and efficiency. Another object of the present invention is to provide an air refrigerant cooling/heating system with a simplified configuration using the air refrigerant type cooling apparatus. To accomplish the purpose, a heat radiating means is provided in a motor of an air refrigerant type cooling apparatus having a compressor, the motor and an expansion turbine in the present invention. Also, a pressure difference is positively generated between the inside and outside of the motor. By these means, when the motor is driven, the heat from the stator main body is exhausted to the outside of the motor through the heat radiating means and the heat from the coil end portions is exhausted through the cooling air exhausted from the inside to the outside of the motor.

Abstract: A refrigeration air conditioner includes a first equalizer pipe connecting a bottom portion of a first hermetic vessel, which contains a main compression mechanism and lubricating oil, to a bottom portion of a second hermetic vessel, which contains an expansion mechanism, a sub-compression mechanism, and lubricating oil. A second equalizer pipe connects a side of the second hermetic vessel at a position higher than a minimum oil level to a suction side of the main compression mechanism. The space within the second hermetic vessel is isolated from the expansion mechanism and the sub-compression mechanism, and the pressure within the second hermetic vessel is not dependent upon the pressure within the expansion mechanism and the pressure within the sub-compression mechanism.

Abstract: An aircraft adaptive power thermal management system for cooling one or more aircraft components includes an air cycle system, a vapor cycle system, and a fuel recirculation loop operably disposed therebetween. An air cycle system heat exchanger is between the air cycle system and the fuel recirculation loop, a vapor cycle system heat exchanger is between the vapor cycle system and the fuel recirculation loop, and one or more aircraft fuel tanks are in the fuel recirculation loop. An intercooler including a duct heat exchanger in an aircraft gas turbine engine FLADE duct may be in the air cycle system. The system is operable for providing on-demand cooling for one or more of the aircraft components by increasing heat sink capacity of the fuel tanks.

Abstract: A fluid machine (201) includes: a compression mechanism (2) for compressing a working fluid; an expansion mechanism (4) for expanding the working fluid and for recovering mechanical power from the expanding working fluid; a shaft (5) for coupling the compression mechanism (2) and the expansion mechanism (4) and for transferring the mechanical power recovered by the expansion mechanism (4) to the compression mechanism (2); and a closed casing (1) for accommodating the compression mechanism (2), the shaft (5) and the expansion mechanism (4), and having an internal space into which the working fluid that has been compressed by the compression mechanism (2) is discharged. A refrigerant passage space (7) through which a refrigerant to be drawn into the expansion mechanism (4) passes is formed between an expansion chamber of the expansion mechanism (4) and the internal space of the closed casing (1).

Abstract: An apparatus for cooling, comprising: a liquid pump for transport of fluid through a heating cycle, an external heat source for heating the fluid in the heating cycle, for example a solar heater directly connected to the heating cycle or connected through a heat exchanger, an expander with an expander inlet and an expander outlet, the expander inlet having a fluid connection to the external heat source for receiving fluid in the gas phase to drive the expander by expanding the fluid, a compressor with a compressor inlet and a compressor outlet, the compressor being driven by the expander for compressing working fluid from a low pressure compressor inlet gas to a high pressure compressor outlet gas, a first heat exchanger with a fluid connection to the compressor outlet and connected to the expander inlet for transfer of heat from the high pressure compressor outlet gas to the fluid in the heating cycle, a second heat exchanger with a condenser for condensing the working fluid from the expander by energy trans

Abstract: An avionics cooling system including an avionics cooling circuit operating with a liquid coolant; a fuel circuit; and a vapor cooling cycle operating with a refrigerant. The avionics cooling circuit transfers heat withdrawn from avionics to the fuel circuit, whereby the heat is dumped into fuel, and the vapor cooling cycle transfers heat that cannot be dumped into the fuel from the fuel circuit to ram air.

Abstract: An air conditioning apparatus that includes a turbine and a compressor with rotors mounted on and fixed to a common rotatable shaft with a heat exchanger located between the turbine and the compressor. The air conditioning apparatus turbine has an inlet that is connected to a source of air such as aircraft ram air the outlet from the turbine and is positioned to direct outlet air from the turbine to the heat exchanger. The compressor which is located adjacent to and downstream from the heat exchanger has an inlet that is positioned to receive air exiting from the heat exchanger. In one embodiment, no external power is necessary to obtain cooling of liquid coolant located within the heat exchanger that is integral with the air conditioning apparatus and another embodiment includes test equipment.

Abstract: An air cycle machine includes a turbine wheel, a turbine inlet nozzle, a valve body, and a poppet member. The turbine wheel is mounted to rotate within the air cycle machine and the turbine inlet nozzle is positioned to direct airflow thereto. The poppet member selectively extends into the turbine inlet nozzle and the valve body controls a pressure on the poppet member to move the poppet member relative to the turbine inlet nozzle to vary the size of the turbine nozzle directing airflow to the turbine wheel.

Abstract: System and method for storing and releasing energy comprising directing air into a vertical cold flue assembly. The assembly has an air inlet at or near the top and an air exit at or near the bottom. The air is cooled and a portion of moisture is removed from the air.

Abstract: A cooling system with a compression cooling cycle for a working fluid that passes an expendable fluid through a warm side heat exchanger for the cooling system to cause the expendable fluid to vaporise and thus absorb heat from the working fluid by way of latent heat or enthalpy of vaporisation and then running the vaporised expendable through a turbine that drives a compressor for the cooling system.

Abstract: A new type of progressive cavity compressor is intended primarily for 3 to 10 ton vapor-cycle air conditioning systems. Major working section elements include a rotor, a stator, inlet ports, an outlet endplate, and outlet check valves. The helical rotor is driven in an eccentric orbital path inside the helical stator. In the preferred embodiment, the rotor and stator helices have varying (non-uniform) pitch in the working section. Rotor-stator running clearances are tight, to minimize leakage. Two outlet check valves regulate refrigerant discharge flow and pressure. Efficient compression is provided over a wide range of compression ratios, corresponding to a wide range of ambient temperatures in an air conditioning application. The invention can improve the energy efficiency of air conditioning systems, especially at off-design conditions.

Abstract: An energy supply system for operating at least one air conditioning system of an aircraft, comprises at least one air line network and at least one electric line network. The air line network is connected to the air conditioning system and at least one bleed air connection for routing bleed air to the air conditioning system. The electric line network is connected to the air conditioning system and at least one electrical energy source for routing electrical energy to the air conditioning system. The air conditioning system has an electrically operable cooling device. By means of the energy supply system according to the invention the energy withdrawn from the power units is better adapted to the energy necessary for operating the air conditioning system and other systems—such as, for example, wing de-icing—and therefore reduces the excess fuel consumption of the aircraft.

Abstract: A system for the provision of process air comprises a first cooling system (2) with a first heat exchanger, which is arranged in a channel (3) that serves as a cooling sink, and a cooling system (8), integrated in the first cooling system (2), wherein said cooling system (8) comprises a heat exchanger (9) which is integrated in the channel (3) either upstream or downstream of the first heat exchanger.

Abstract: The present invention provides a technique for rapidly removing frost accumulated in air-refrigerant cooling apparatuses. An air-refrigerant cooling apparatus in accordance with the present invention includes a bypass line for directly supplying a defroster with refrigerant air having an increased temperature from a compressor, avoiding temperature drop by a heat exchanger and an expansion turbine. Moisture of the frost melted in the defroster is externally exhausted by a fan.

Abstract: The subject system is an air conditioner system for vehicles that uses compressed air as the means of powering the airconditioner refrigerant cycle instead of mechanical or electrical means. The subject system is designed to capture and store braking energy by compressing air and recharging a compressed air reservoir while the vehicle is under deceleration. The air compressor can also be powered from the main vehicle engine or motor to recharge the compressed air reservoir at other times. The stored compressed air system allows the air conditioner to be operated independently of the main vehicle motor. This system does not provide motive power for the vehicle.

Abstract: An engine/heat pump is shown. Most of its parts rotate around the same central axis. It comprises two doubly connected chambers. Blades in each chamber substantially rotate with the chamber and may be firmly attached to the walls of the chamber, thus forming a modified centrifugal pump with axial input and discharge. An expandable fluid is rotated outward by one of the pumps and then heat is added for an engine or removed for a heat pump as the fluid is being sent to the outer part of the second pump. The fluid travels toward the center of the second pump, thus impelling the pump in the rotation direction. Then heat is removed for an engine or added for a heat pump as the fluid leaves the second pump and travels back to the first pump near the center of rotation of both pumps. Rotation energy of the fluid is typically much larger than the circulation energy. A modified centrifugal pump with axial discharge having a casing rotating with the blades is also claimed.

Abstract: An object is to provide an apparatus which performs freezing and heating with a high efficiency. A compressor generates an air refrigerant with a high temperature and a high pressure by compressing the air refrigerant. As the air refrigerant is heated by a first heat exchanger and further heated by a heater, the temperature of the air refrigerant is increased to more than 200° C. in which bread and cookies can be baked, and the air refrigerant is supplied to an oven. Heat of the air refrigerant outputted from the oven is recovered by a second heat exchanger, and supplied to a high-temperature side of the first heat exchanger. The air outputted from the second heat exchanger is cooled by a cooler and a third heat exchanger, is adiabatically expanded by an expansion turbine to be cooled to ?85° C., and is supplied to a freezer. The air of the freezer is recovered to be supplied to the low-temperature side of the third heat exchanger, and then is supplied to the compressor.

Abstract: The object of the present invention is to cool an inside space of cooling warehouse uniformly by using a air refrigerant type cooling apparatus. A piping for taking in air in the cooling warehouse is installed. The air taken in by the piping (higher temperature) is mixed by the air sent from the air refrigerant type cooling apparatus (lower temperature) and blown off to the cooling warehouse. The temperature of the mixed air is closer to the temperature inside of the cooling warehouse than the air sent from the air refrigerant type cooling apparatus so that the inside of the cooling warehouse is cooled more uniformly. Furthermore, the amount and speed of the air blown off into the cooling warehouse are increased so that the inside space of the cooling warehouse is more uniformly cooled.

Abstract: Aircraft environmental control systems having a single ram air inlet providing air to both cabin air compressors and associated heat exchangers are disclosed herein. In one embodiment, and environmental control system for use with an aircraft includes a ram air inlet, an air conditioning pack, and an associated heat exchanger. In this embodiment, the ram air inlet provides a first portion of air to the air conditioning pack, and a second portion of air to the associated heat exchanger. The first portion of air flows from the air conditioning pack and through the heat exchanger before flowing into an aircraft cabin. The second portion of air from the ram air inlet cools the first portion of air in the heat exchanger before exiting the aircraft through a ram air outlet. The inlet and outlet can be modulated on an optimized schedule to minimize the net drag of the ram system.

Abstract: A method and a system for the preparation of compressed air having a heat exchanger (system heat exchanger) which is in communication with a pressure source on the inlet side on the compressed air side and which is in communication with a system or unit on the outlet side on the compressed air side which is to be supplied with cooled compressed air and including at least one heat exchanger (air conditioning system heat exchanger) which is in communication with a pressure source on the inlet side on the compressed air side and which is in communication with additional components of an aircraft air conditioning system on the outlet side on the compressed air side.

Abstract: A rigid or semi-rigid demister pad is positioned between an air turbine and an inertial water removal device such as extractor in an air conditioning system for an aircraft. The demister pad comprises packed fibers or strands whose diameter typically ranges from approximately 10 or fewer microns to approximately 280 microns. The demister is capable of catching very small droplets discharged from the air turbine that coalesce into larger droplets that exit the demister pad and enter an adjacent water removal device downstream from the pad to separate the larger water droplets from the stream of air. This avoids using a water separator containing a coalescer bag that requires frequent maintenance and is sensitive to dirt and freezing. The demister can operate at freezing temperature, is not dirt-sensitive and requires no maintenance.

Abstract: A sub-compressor (23) is provided between a compressor (22) and a power-recovery device (24). A refrigerant after preliminarily being compressed by the sub-compressor (23) is allowed to flow into the compressor (22). Since the sub-compressor (23) and the power-recovery device (24) have approximately the same temperature, heat transfer hardly occur therebetween. Heat transfer occurs between the compressor (22) at high temperature and the sub-compressor (23) at low temperature. However, even if the heat from the compressor (22) heats the refrigerant in the sub-compressor (23), the refrigerant discharged from the sub-compressor (23) is delivered to the compressor (22), and thus the temperature of the sub-compressor (23) scarcely increases.

Abstract: An expander-compressor unit (200) includes a closed casing (1), a compression mechanism (2), an expansion mechanism (3), a shaft (5), and an oil pump (6). The shaft (5) includes an upper shaft (5s) provided with an upper eccentric portion (5a) for the compression mechanism (2), and a lower shaft (5t) provided with lower eccentric portions (5d and 5c) for the expansion mechanism (3) and an intermediate eccentric portion (5e) for the oil pump (6). The expansion mechanism (3) has an upper bearing member (45) for supporting a supported portion (5f) of the lower shaft (5t) located immediately above the lower eccentric portion (5d). The intermediate eccentric portion (5e) has a diameter equal to or less than that of the supported portion (5f).

Abstract: It is an object of the present invention to reduce the constraint that the density ratio is constant as small as possible, and to obtain high power recovering effect in a wide operation range. A refrigeration cycle apparatus uses carbon dioxide as refrigerant and has a compressor, an outdoor heat exchanger evaporator, an expander and an indoor heat exchanger a radiator. An injection circuit for introducing high pressure refrigerant is provided in a halfway of an expansion process of said expander.