Abstract: The invention relates to a refrigeration system of the air cycle cooling system type, also called reversed Brayton cycle in which the air flow through compressor means (12, 16), heat exchanger means (24) for withdrawal of heat from the compressed air and finally expander means (22) from where it is delivered to perform cooling. According to the invention the system includes heat load means (41) having a large flow resistance, creating a considerable over-pressure at the expander outlet (23). A rotary screw machine is included in the expander (22) and also in the compressor means (12, 16), which latter screw rotor machine (12) is driven solely by the screw rotor machine (22) of said expander means.

Abstract: An integrated environmental control system is disclosed for providing conditioned supply air to loads such as a passenger cabin of an aircraft. The system comprises at least two shafts, each shaft having a fan, compressor, and turbine mechanically secured to the shaft; common heat transfer components including primary and secondary heat exchangers, a reheater, and a condenser with a water collector; lines that deliver the supply air separately through the compressors and turbines of each shaft and deliver the supply air in common through the common heat transfer components to the load; and shutoff valves secured in fluid communication with each turbine.

Abstract: Unconditioned, sub-freezing turbine exhaust air is employed to cool liquid coolant from radar electronics in an aircraft. This is accomplished by utilizing a liquid/air exchanger. However, in order to ensure that the air-cooled heat exchangers do not experience freezing of moisture droplets, sufficient heat is supplied to a liquid/air heat exchanger, located at the turbine exhaust, to maintain all surfaces (fins) above freezing, and also to heat the entire turbine exhaust air stream to a temperature above freezing as it exits that heat exchanger. Use of this anti-icing liquid/air heat exchanger, in conjunction with the proper air and liquid flow controls, will permit savings of total cooling air (i.e., engine bleed air) flow by negating the need for a hot air bypass to reheat turbine exhaust air.

Abstract: A dual-pack, aircraft environmental control system has each pack dedicated to providing a temperature-controlled air supply to a corresponding compartment, either the crew or passenger, of the aircraft. Each refrigeration pack is fed hot, compressed bleed air from an associated turbine engine on the aircraft. During normal operation, the pack associated with a particular compartment on the aircraft provides the air supply with independent temperature control to that compartment. However, during failure of one of the refrigeration packs and the resulting operation of the other pack, the environmental control system is able to provide independent temperature control of the air supplied to each compartment.

Abstract: A refrigeration device in which a heat load is refrigerated within a refrigeration chamber. Refrigerant is supplied, preferably, from a supply of turboexpanded air employing a compressor to compress the air and a turboexpander to expand the compressed air to a low temperature. A venturi-like device such as an ejector circulates the refrigerant within a circulation path within the refrigeration chamber so that heat is transferred from the heat load to the refrigerant. An incoming mass flow rate of the refrigerant is delivered to a high pressure inlet of the venturi-like device and a recirculation mass flow rate of the refrigerant is received within the low pressure inlet from the circulation path after the refrigerant has heat transferred thereto. A high pressure outlet discharges a mixture of the refrigerant that comprises the incoming and recirculation mass flow rates to the circulation path and prior to the heat load.

Abstract: An air cycle machine (10) has a first stage turbine (60) mounted to a central portion of a common shaft (12), a compressor (50) mounted to the central portion of the shaft (12), a second stage turbine (30) mounted to a first end of the shaft (12), and a fan (40) mounted to a second end of the shaft (12), all for rotation therewith about a longitudinal axis (14). The first and second stage turbines (60, 30) are operative to extract energy from a flow of compressed air for driving the shaft (12), and the fan (40) and the compressor (50), in rotation about the axis (14).

Abstract: In a normal mode, a primary heat exchanger for heated bleed airflow is situated upstream of an aircraft air conditioner compressor. A secondary heat exchanger is located downstream of the compressor. In response to hot and humid environmental conditions, three-way switching valves reposition the primary heat exchanger downstream of the compressor. The result will be the reduction of heat exchange exit temperature, which translates into lower turbine inlet and outlet temperatures at satisfactory airflow rates.

Abstract: To prevent icing in an auxiliary refrigerated air system utilized in jet aircraft for environmental control purposes, wherein high pressure, high temperature input air bleed from the engine compressor is boosted in pressure and temperature, cooled in a heat exchanger and expanded in a turbine to produce refrigerated output air flowing through an output duct, a portion of the input air is diverted to warm appropriate parts of the expansion turbine to prevent ice accretion thereto. To prevent icing of the output duct, input air is also diverted to warm the duct wall. Alternatively, the engine fuel line is coiled about the output duct in heat exchanging relation to warm the duct wall.

Abstract: A vehicular cooling apparatus is arranged to include a compressor directing cooling and compressed air through a directional tube from a storage flask into an associated cooling chamber. Inlet air is directed through the cooling chamber into the vehicular passenger compartment. Typically, the use of freon is eliminated by use of the directional tube.

Abstract: A cooling system includes a turbo compressor for compressing a coolant and a turbo expander fluidically connected to the turbo compressor via one or more heat radiators. In order to insure a constant expansion ratio in the turbo expander at all operating temperatures, without varying the rotational speed of the turbo compressor, a first controller controls the flow rate of coolant to the turbo expander while a second controller in a bypass passage controls a flow rate of coolant bypassed to the intake side of the turbo compressor. The first and second controllers are controlled by a control unit sensitive to the coolant temperature at the intake side of the turbo expander.

Abstract: A compact, air cycle air conditioning system including compressor, turbine, heat exchanger and high speed electric motor is thermostatically controlled to supply either hot or cold conditioned air to a load air space. In a second arrangement, compact, exhaust gas driven air cycle air conditioning system including a compressor, turbine, two heat exchangers and an exhaust turbine is controlled by means of an exhaust gas bypass arrangement and supplies either hot or cold conditioned air to a load air space. In a third arrangement compact, exhasut gas driven air cycle air conditioning system includes an expansion turbine, two compressors, two heat exchangers and an exhaust turbine which is preferably controlled by means of an exhaust gas bypass arrangement and supplies either hot or cold conditioning air to a load air space.

Abstract: An air-cycle air conditioning system comprises a first turbine disposed in an exhaust passage of a prime mover and driven by the energy of exhaust gases, a first compressor placed in coaxial relation to the first turbine and rotatable in response to the operation of the first turbine so as to intake and compress an air, a second turbine coupled to an outlet end of the first compressor through a first line and rotatable by the energy of a compressed air from the first compressor so as to expand and cool the compressed air, a first heat exchanger disposed in the first line and effecting heat exchange between the compressed air and an outside air, a second heat exchanger connected to the second turbine through a second line and effecting heat exchange between the air supplied from the second turbine and an air supplied from a fan, a second compressor placed in coaxial relation to the second turbine and rotatable in response to the operation of the second turbine so as to intake and compress an air, an auxiliary

Abstract: In an air cycle environmental control system, a condenser (46) removes water vapor from compressed, ambient, supply air (9) before it is expanded in a first turbine (24). The chilled outlet air (49) from the first turbine (24) is then used as coolant in the condenser (46), absorbing there the heat of vaporization of the condensed water vapor. After passing through the condenser (46), the warmed coolant is then expanded in a second turbine (26). Should the pressure of the supply air fall below predetermined levels, portions of the cycle that degrade performance or become unnecessary are bypassed.

Abstract: An advanced hybrid air and vapor cycle environmental control system (ECS) to provide conditioned, pressurized air to an aircraft as well as liquid cooling for the avionics of the aircraft.

Abstract: A hybrid vapor cycle-air cycle environmental control system (ECS) for efficiently providing a flow of conditioned, pressurized air to an enclosed space such as an aircraft cabin.

Abstract: A ram air cooling system for cooling electronic components in an aircraft ovides automatic switching from a high ram air speed cooling mode (ACM) to a low ram air speed cooling mode (RAM). The cooling system receives variable speed ram air during the flight of the aircraft and includes an automatically controlled valve for either directing high speed ram air to a precooling means prior to cooling the electronic components or directing low speed ram air directly to the electronic components without precooling. The automatically controlled valve is controlled by programmable logic module means for comparing the cooling efficiency of the electronic components by precooled ram air with the cooling efficiency of the electronic components by the non-precooled ram air. The cooling efficiencies are calculated from temperature measurements of the ram air at several locations in the system of the invention.

Abstract: An air cycle refrigeration system which comprises an air-to-air heat exchanger, first and second turbochargers, and first and second ejector pumps. The system air to be cooled is passed through the heat exchanger and into a first turbine, cooling upon expansion and driving the coupled first compressor. The system air passes from the first turbine to the second turbine, again cooling upon expansion and driving the coupled second compressor. Each compressor is connected with the coolant air outlet of the heat exchanger and draws the coolant air therefrom. The high pressure air produced from the outlets of the compressors are used to drive corresponding ejector pumps. The ejector pumps are connected with the coolant air outlet of the heat exchanger and draw additional air therefrom. The total draw of coolant air through the heat exchanger therefore comprises the total of the inlet air to the two compressors and the induced air drawn from the heat exchanger by the two ejector pumps.

Abstract: A cryocooler system including a reversed Brayton cycle turbo-refrigerator system having a surge control valve in the bypass line between the compression section inlet and outlet. The compression section includes at least one compressor and an aftercooler which rejects the heat of compression to a heat sink. The cooling section includes at least one regenerator and a turbo-alternator for expansive cooling of the working fluid.

Abstract: A pressure regulating valve controller for controlling the flow of refrigerant airflow through one of a plurality of air cycle systems is described. The controller includes pressure regulating means (145) for controlling flow in response to changes in ram air temperature as well as pressure regulating means (140 and 315) in response to the number of operating air cycle systems.

Abstract: A generator for producing pure air at high pressure includes a compressor, electrical means for driving the compressor and means for purifying compressed air generated by the compressor. A first sensor is provided for detecting the pressure of the compressed air and a second sensor for detecting the absolute temperature of that air. Means is provided for transferring an electrical signal from the first sensor to an electronic controller. Means is also provided for transferring an electrical signal from the second sensor to the controller. The controller processes these electrical signals and varies the power supplied to the means for driving the compressor in such a manner that the ratio of pressure of the compressed air to the absolute temperature of the compressed air remains substantially constant.

Abstract: An air cycle air conditioning system (10) for rgulating the temperature and pressure of diverse loads includes open and closed loop sections (12) and (16). A first load (14) requiring heating or cooling with constantly supplied fresh air is provided with chilled air from first turbine (75) and warm air from first bypass valve (50). A second load (20) which can be heated or cooled with a supply of recirculating air is provided with chilled air from second turbine (130) and warm air from a second bypass valve (170). Air is supplied to the second turbine from a compressor driven by the first turbine whereby the first turbine maintains the temperature of both loads either by the direct supply of air thereto or by driving another turbo-compressor system.

Abstract: The invention is an energy-efficient all-electric environmental control system (70). The system includes a cabin compressor (16) and a Freon compressor (14), both of which are commonly driven by a two-speed electric motor (12). The motor (12) operates at low speed at low altitudes and on the ground to drive the Freon compressor (14). Freon fluid then cools the electric motor (12) and the cabin (18) and avionics (56) by means of the evaporator/dehumidifier systems (72) and (74), respectively. At high altitudes the electric motor (12) runs at high speed to drive the cabin compressor (16) to provide pressurization for the cabin (18). In this operation mode, the Freon compressor can be disconnected via an electromagnetic clutch (48).The ECS (70) also includes a liquid Freon pump (52) which can be utilized when the Freon compressor is disconnected or bypassed to circulate liquid Freon to cool the electric motor (12) and to circulate through the evaporators (38) and (76).

Abstract: The liquid level in at least one flash economizer associated with a refrigeration process is maintained at a desired level by controlling the flow of the liquid leaving the flash economizer in response to a control signal which is responsive to the difference between the actual liquid level in the flash economizer in the desired liquid level. The liquid level in the chiller associated with a refrigeration process is maintained by controlling the flow of fluid to the flash economizer in response to a control signal which is responsive to the difference between the actual liquid level in the chiller and the desired liquid level.

Abstract: An air cycle refrigeration system (10) pressurizes and cools flight compartment (115) and cabin (120) by the provision of chilled air thereto. Trim valves (180) and (205) set by a common actuator (195) control the mixture of uncooled system inlet air with the chilled air for individual regulation of the temperatures of the cabin and flight compartment.

Abstract: The invention is an energy-efficient all-electric environmental control system (70). The system includes a cabin compressor (16) and a Freon compressor (14), both of which are commonly driven by a two-speed electric motor (12). The motor (12) operates at low speed at low altitudes and on the ground to drive the Freon compressor (14). Freon fluid then cools the electric motor (12) and the cabin (18) and avionics (56) by means of the evaporator dehumidifier systems (72) and (74), respectively. At high altitudes the electric motor (12) runs at high speed to drive the cabin compressor (16) to provide pressurization for the cabin (18). In this operation mode, the Freon compressor can be disconnected via an electromagnetic clutch (48).The ECS (70) also includes a liquid Freon pump (52) which can be utilized when the Freon compressor is disconnected or bypassed to circulate liquid Freon to cool the electric motor (12) and to circulate through the evaporators (38) and (76).

Abstract: An air cycle refrigeration system (10) for cooling and ventilating an enclosure such as an aircraft cabin (15) includes a circulation heat exchanger (145) for absorbing heat from air within the cabin, a sink heat exchanger (120) for delivering the heat absorbed from the cabin air to exhaust air from the system's turbine (80) and for melting ice in the exhaust air. A heat exchange liquid circulates through both heat exchangers in a single loop (100). The circulation heat exchanger (145) may be located in the interior of the cabin (15).

Abstract: A device for supplying cooling air under pressure, e.g. for cooling the electric apparatus in an aeroplane at rest on the ground, comprising an internal combustion motor, such as a diesel motor, an air compressor having its suction line connected to the atmosphere, the pressure side of this air compressor supplying air under pressure; and a cooling circuit for cooling this air under pressure, said cooling circuit including a compressor, a condenser and a cooler. A cooler with air-cooling is operative between the air compressor and the said cooler in the cooling circuit, while actuating means, which reacts to the temperature of the atmosphere switches the compressor in the cooling circuit on and off when the temperature of the atmosphere rises or falls to a predetermined value.

Abstract: An air cycle refrigeration system having an enhanced flow capacity range includes an expansive turbine fed through a primary inlet nozzle by discharge air from the system's compressor and through a secondary inlet nozzle by system supply air. Flows through the turbine inlet nozzles are controlled such that maximum flow through the primary inlet nozzle is achieved before flow through the secondary nozzle is instituted.

Abstract: An air cycle refrigeration system in which cabin exhaust air is utilized to regeneratively cool the pressurized working fluid before expansion thereof through a cooling turbine and introduction in the cabin.

Abstract: This invention relates to an airconditioning system to provide environmental control for an aircraft's cabin or cockpit. The system cooling cycle includes in combination: a rotary power supply and a turbomachine which includes a power compressor secured to a power shaft for providing compressed air. The rotary power supply is drivingly coupled to the power shaft to operate at a given speed. An expansion cooling turbine is mounted on a shaft concentric to the power shaft. A power driven fan is provided for directing a source of ambient air to and through a heat exchanger. The power compressor is coupled respectively to the cabin and through the heat exchanger to an input of the expansion cooling turbine to thereby draw air from the cabin and deliver the compressed air to the expansion cooling turbine. The expansion cooling turbine is designed to operate at a different speed than the given speed of the power shaft.

Abstract: An aircraft cabin is climatized by tapping air from the engine compressors and feeding it into the cabin through a loop which includes a compressor, a cooling turbine driving the compressor, and several cooling stages. A second loop, using preferably helium, includes a second compressor and a second turbine, the second compressor being driven by both turbines, and the cooled helium is in heat exchange with another cooling loop which runs through instrument compartments. Discharged cabin air is used to precool the compressed helium.

Abstract: An aircraft cabin air-conditioning system, of the type that uses engine bleed air, regulates the amount of tapped bleed air so as to be just sufficient to maintain a desired cabin pressure, thus minimizing the fuel burn allocated to the aircraft's environmental control system. The air-conditioning system cools the bleed air by passing it first through a heat exchanger 50 of a circulating glycol/water coolant loop 55 for heat transfer to a coolant and then through an evaporator 60 of an electrically-driven vapor-cycle loop 56 for supplemental heat transfer to a refrigerant. The rate at which the refrigerant is circulated through the evaporator 60 is regulated to be just sufficient to provide a required supplemental cooling capacity, thereby minimizing electrical power consumed by a compressor 63 that forms part of the vapor-cycle loop 56. A subbranch of the coolant loop 55 carries the coolant through a condenser 64 of the vapor-cycle loop 56 where there is an additional transfer of heat to the coolant.

Abstract: In an air conditioning system for an aircraft cabin, stale air is withdrawn from the cabin, then filtered, compressed and cooled in a recirculation loop which returns the reconditioned air to an air distribution manifold that supplies the cabin with fresh air. The compression stage moves the air through the recirculation loop and is provided by an air compressor driven by a power turbine that is in turn rotated by a flow of cabin air to an overboard exhaust nozzle caused by a cabin-to-ambient pressure differential. Cooling is provided by an air/air heat exchanger that transfers heat from the recirculation air, warmed by the compression stage, to cooler air discharged from the output side of the power turbine and flowing to the overboard exhaust nozzle. In one embodiment, the foregoing recirculation loop is integrated with an air cycle machine refrigeration stage of a conventional cabin air conditioning system supplied by fresh engine bleed air.

Abstract: The air supply to an aircraft is provided by air conditioning apparatus operable in a powered bootstrap simple cycle or bootstrap cycle mode. Logic circuitry selects and activates the system to that mode best suited to existing conditions.

Abstract: Fluid to be conditioned is admitted to first passageways of a heat exchanger and thereafter to a point of use, traversing flow conducting means which include the second passageways of the heat exchanger and fluid conditioning means which reduces the energy level of the fluid admitted to the second passageways below the energy level of the fluid admitted to the first passageways so as to increase the energy level of the fluid flowing through the second passageways by heat exchange with the fluid flowing through the first passageways.

Abstract: An environmental control system comprises a working gas circuit including a compressor-expander arrangement and first heat exchange means by which the working gas is conditioned before being passed to second heat exchange means connected in the circuit in heat exchange relationship with an environment to be controlled. The working gas is provided with means for regulating the mass of working gas in the circuit in response to the conditioning demand on the system. One such regulating means comprises an inlet path for admitting working gas to the circuit and an outlet path for removing working gas from the circuit.

Abstract: An air conditioning system for an enclosed space including a jointly driven compressor and expander of the positive displacement type each having an inlet port and an outlet port with a primary heat exchanger connected between the compressor outlet port and expander inlet port and a secondary heat exchanger connected between the expander outlet port and the compressor inlet port to complete a closed loop having a charge of air and with one of the heat exchangers being thermally coupled to the enclosed space. Ambient air is injected into the closed loop to raise the pressure in the secondary heat exchanger to substantially above the atmospheric level to increase the heat rate of the system. Alternatively air is bled from the loop to reduce the pressure in the secondary heat exchanger thereby to decrease the heat rate of the system. In an alternate embodiment a source of pressurized air is provided, preferably in the form of an accumulator, with valving to feed air from the accumulator into the loop.

Abstract: An air conditioning system for an enclosed space which includes a compressor and expander having inlet and outlet ports with a primary heat exchanger connected between the compressor outlet port and the expander inlet port and a secondary heat exchanger connected between the expander outlet port and the compressor inlet port to complete a closed loop having a charge of air, one of the heat exchangers being thermally coupled to the enclosed space. A pump is provided for injecting air into the loop to increase the pressure therein thereby to increase the heat rate of the system. Preferably the pump is used for both injecting air into the loop and bleeding air from the loop under the control of a thermostat for maintenance of a set temperature; however, a simplified form of the invention employs constant bleed. In a more elaborate form of the invention pressure follow-up is incorporated in the control to avoid any tendency toward overshoot.

Abstract: An open loop air cycle air conditioning system draws ambient air into a turbine for expansion and cooling. The air passes through a heat exchanger where it withdraws heat from recirculated cabin air and is passed to a compressor which is operatively coupled to and driven by the turbine to partially recompress the air. The air is directed from the compressor to the intake manifold of the airplane engine. Valves may be positioned at the ambient air inlet to control the flow of air through the air conditioning system and into the engine. Water can be sprayed into the low pressure air at the heat exchanger to provide substantial additional cooling by evaporation.

Abstract: Air at substantially ambient pressure is cooled in a heat exchanger and introduced into an enclosure for cooling. The air is withdrawn from the enclosure and a portion of the air is expanded through a turbine for additional cooling and passed through the heat exchanger for the removal of heat therefrom. The air is then compressed to substantially ambient pressure and expelled. Additional cooling of the expanded air from the turbine may be obtained by evaporating a fluid therein. The fluid may be water condensed in, and withdrawn from, the heat exchanger.

Abstract: Inlet air for an internal combustion engine in an airplane is expanded through a turbine to lower its pressure and temperature and is passed through a water chiller wherein heat exchange and evaporative cooling substantially lower the temperature of the water. The air is then fed to a compressor driven by the turbine and its pressure is raised to a level suitable for input to the engine manifold. The chilled water is circulated through a heat exchanger to provide cooling for the cabin of the airplane.