Showing papers on "Thermal expansion valve published in 1981"

Pump-assisted heat pipe

Abstract: A closed-loop heat transfer system comprises a heat pipe (10) and an external liquid-phase pump (11). The heat pipe (10) includes an evaporator (12) and a condenser (13) connected by a conduit (14). The evaporator (12) is a hollow structure having an interior surface defining an evaporation region in which a working field in liquid phase absorbs heat from a heat source by evaporation. A capillary pumping structure, e.g., capillary channels (30) or a fine-mesh screen (41), is provided on or adjacent the interior wall of the evaporator (12). Evaporated working fluid laden with heat is thermodynamically driven substantially adiabatically via the conduit (14) from the evaporator (12) to the condenser (13), wherein the working fluid rejects heat to a heat sink by condensation. Condensed working fluid is thereupon returned from the condenser (13) to the evaporator (12) via external conduits (22, 15) by means of the liquid-phase pump (11). The capillary pumping structure inside the evaporator (12) serves to maintain a constant supply of working fluid in liquid phase adjacent the interior surface of the evaporator (12), thereby promoting efficient transfer of heat from the heat source to the working fluid in the evaporator (12). There is no limitation on the length of the heat pipe (10) caused by capillary pumping requirements of the system. Pursuant to 37 CFR 1.72(b), the foregoing abstract shall not be used for interpreting the scope of the claims herein.

Load management control air conditioning system

Abstract: An air conditioning system for providing an air cooling operation during a load phase management shutdown of the air conditioning compressor utilizes a thermally insulated cold water tank for storing chilled water. The water is cooled by a free cooling effect using wet bulb temperature drop of a refrigerant circulating between a secondary coil in a condenser section of the air conditioning system and a heat exchanger in the chilled water tank located below the condenser. The secondary coil in the condenser is cooled by a waterspray which can advantageously be derived from the condensate obtained from the evaporator section during a compressor operation phase of the air conditioning system. The chilled water is supplied to a chilled water coil in an evaporator section to cool the air flow in a chilled water cooling operation when the air conditioning compressor is inoperative during the load management phase of the peak hour of the air conditioning system.

Refrigerating system using scroll type compressor

Abstract: A refrigerating system including a refrigeration circuit and a scroll type compressor provided with two volume control mechanisms to allow the system to selectively perform full load operation and unloaded operation. The scroll type compressor includes two scroll members of known construction meshing with each other to define compression chambers and a suction chamber and is combined with the refrigeration circuit having an outdoor heat exchanger, an expansion valve, an indoor heat exchanger and a four-way change-over valve to provide a heat pump type refrigerating system. The volume control mechanisms each include a pair of bypass apertures in the fixed scroll member communicating with a valve chamber having a valve member slidably mounted therein and normally biased to an open position by a spring. The bypass apertures, of which one communicates with the suction chamber and the other communicates with one of the compression chambers, and the valve chamber constitute a bypass passageway. A pressure introducing pipe opens in the valve chamber. Upward movement of the valve member brings the two bypass apertures in communication with each other through the valve chamber to enable the system to perform a volume control operation. In another application, four volume control mechanisms are located symmetrically and divided into two blocks through a flow passage switching device to assign two mechanisms to one block. By this arrangement, the system is able to perform volume control operation in three stages, or able to operate selectively at maximum load, intermediate load and minimum load.

Distributor for plate fin evaporator

Abstract: A distributor for feeding the liquid-vapor mixture of refrigerant from the expansion valve to the core elements of an evaporator of an air conditioning system to provide equal distribution of both the liquid and vapor components. The distributor involves either a single header with separate orifices for the liquid and vapor in each core element or a pair of distribution headers to carry the separated component phases from a separator with an orifice for each phase in each core element where the phases would be recombined to pass through the core elements to a common outlet.

Transport refrigeration machine

Abstract: A transport refrigeration machine for conditioning the interior of a trailer comprising a frame, a refrigerant compressor, a condenser assembly, and an evaporator assembly. The evaporator assembly includes a housing, a heat exchanger extending within the housing for conducting the refrigerant fluid therethrough, and heat exchanger support apparatus connecting the heat exchanger to the frame to support the heat exchanger independently of the housing. The evaporator assembly further comprises a blower unit extending within the housing to circulate air therethrough, and blower unit support apparatus connecting the blower unit to the frame to support the blower unit independently of the housing.

Air-conditioning apparatus for motor vehicles

Abstract: Air conditioning apparatus for conditioning the air supplied to a vehicle passenger space is provided which includes an air conditioning air cooling evaporator and an air heater unit arranged in series. An evaporator bypass duct extends in bypassing relationship to the evaporator and a heater bypass duct extends in bypassing relationship to the heater. To control the temperature of the air conditioned by the apparatus two temperature mixing air flaps are provided, one air flap controlling the proportion of air flow through the evaporator and its bypass duct and the other air flap controlling the proportion of air through the heater and its bypass duct.

Heat pump system using wastewater heat

Abstract: A practical and economical heat pump system stacks the evaporator, compressor, condenser, and expander to use heat from household wastewater more efficiently and effectively. A novel wastewater storage tank treats the wastewater to remove particulates while it supplies its warmest water to the evaporator to provide heat to the refrigerant in the heat pump unit. Heated water exiting the condenser is stored in a separate tank, such as an ordinary hot water heater. The system automatically ensures that the wastewater does not freeze in a substantial amount in the evaporator.

Heat pump using solar and outdoor air heat sources

Abstract: A heat pump system uses a non-reversing refrigeration circuit having a water-cooled condenser and a counterflow chiller fed by a thermostatic expansion valve to permit operation at close to zero superheat. To protect the compressor in the refrigeration circuit from possible flood-back at this low superheat, a combination suction-liquid heat exchanger-suction accumulator is employed. A hold-back valve serves to maintain constant compressor suction pressure regardless of evaporator pressure fluctuations caused by changing chiller fluid temperatures. The system is designed to operate in four distinct modes: (1) water source heat pump heating; (2) direct solar heating; (3) air source heat pump heating; and (4) heat pump cooling. To switch the refrigeration circuit to heat pump mode from the cooling mode or vice versa, four three-way valves and three fluid pumps are selectively operated. The fluid circuit of the system consists of two separate coils in an air-handling unit. One coil is connected to the solar collector circuit and may be used for either heating or cooling. A second coil is connected to the condenser circuit and works during the heat pump cycle.

Control of vapor compression cycles of refrigeration systems

Abstract: A vapor compression cycle refrigeration system of the type having the expansion valve (11) controlled by a temperature sensing bulb (12) at the downstream end of the evaporator (5). A by-pass line (15) is provided from the expansion valve outlet to the evaporator (5) to inject wet vapor upstream from the temperature sensing bulb (12) and provide proportioned negative feedback to the expansion valve (11) to reduce hunting or oscillating of the system. Variations of the by-pass line are also described to give positive feedback and combinations giving integral and derivative action.

Refrigeration unit comprising compartments at different temperatures

Abstract: A refrigeration unit formed of compartments at different temperatures, separately regulated, comprising a refrigerant circuit equipped with a single motor-compressor, and composed of a primary circuit comprising a capillary tube and several evaporators, and a secondary circuit with a condenser and an evaporator, the condenser forming part of a heat exchanger with one of the primary circuit evaporators, and the evaporator, by a thermal valve effect, cooling the freezer compartment of the unit.

Three-way heat pipe

Abstract: A three-way heat pipe configured in a generally Y-shape having a condenser-evaporator or heat-sink end, an evaporator arm and a condenser arm. In addition to conventional internal pumping the heat pipe is mechanically pumped externally from the heat-sink end to the evaporator arm. Heat transfer can take place between any two of the three elements by thermostatically controlling the external pump. Heat or cold may be stored in a suitable medium surrounding the condenser-evaporator end of the pipe for later transfer through the condenser or evaporator ends used as heat exchangers without a secondary circulation system. Heat transfer may also take place directly between the evaporator and condenser arms without storage. In the preferred embodiment of the heat storage configuration, a valve is placed in the condenser arm to prevent unwanted heat transfer. A system of three-way heat pipes can provide long duration thermal storage of heat or cold energy which can be later used for space heating and/or cooling of buildings.

Bottoming cycle refrigerant scavenging for positive displacement compressor, refrigeration and heat pump systems

Abstract: Scavenging is applied to a conventional refrigeration cycle to return most of the energy normally remaining in a warm condensed liquid to the cycle. This permits considerably more energy to be picked up in the evaporator of the cycle than under conventional practice. The concept is applicable to any type positive displacement compressor where an intake of evaporator generated gas can be trapped in the compressor, with the scavenged gas then added prior to mechanical compression. The concept is particularly applicable to reciprocating compressor type heat pump systems.

Thermostatic expansion valve for a refrigeration system

Abstract: A thermostatic expansion valve is disclosed for a refrigerant system that modulates the fluid flow with a capsulated refrigerant pressure that is temperature regulated through direct heat conduction from the evaporator outlet and further controls the flow with evaporator inlet pressure modulated by a venturi effect.

Variable valve for refrigeration system

Abstract: In an absorption refrigeration system comprising a generator, a condenser, an evaporator, an absorber, a heat exchanger, and a compressor to improve generator output and performance, a variable valve on the line from the generator to the absorber is provided to maintain constant cooling output

Electric expansion valve

Abstract: PURPOSE:To heighten the velocity of response and obtain a long lifetime, by composing a valve driver of a step motor and gears, housing the step motor, the gears, etc. in an enclosed container and using a hermetic seal for the power lines of the motor. CONSTITUTION:A coolant from a coolant inlet pipe 7 passes through the gap between a valve seat 5 and a needle valve 4A and then flows out of an outlet pipe 8. A step motor 1, a gear 3, etc. are housed in an enclosed container 9. Although the coolant enters from the gap between a valve stem 4 and a valve frame 6 into a space defined by the container 9, the coolant does not flow out of the container because it is enclosed. A seal member 10 hermetically seals up connection terminals for leading the power lines 11, 12, 13, 14, 15 of the step motor 1 out of the container 9.

Evaporative condenser refrigeration system

Abstract: The present invention relates to a method and apparatus for operating an evaporative condenser refrigeration system at a low condensing temperature. The refrigeration system includes a condenser, an evaporator, a compressor, and a coolant flowing therethrough. The condenser is sized for sufficient capacity for operation at the annual average wet bulb temperature of the locality of the refrigeration system. The evaporative condenser is operated at full capacity at all times during operation of the refrigeration system. The temperature of the incoming coolant fluid to the condenser is permitted to follow the prevailing wet bulb temperature of the locality. By operating at a low condensing temperature, a compressor arranged in the refrigeration system operates at the lowest practical horsepower requirement. Further, according to the preferred embodiment of the present invention the capacity of a compressor delivering working fluid to the condenser is controlled to ensure that the desired refrigeration load on the evaporator is maintained while using the minimum required compressor horsepower.

Absorption type refrigeration system including compressor driven auxiliary flow circuits isolated from main circuit

Abstract: An absorption type refrigeration system includes a main flow circuit, a first and a second auxiliary flow circuit The main flow circuit includes a refrigerant generator containing a solution of evaporable refrigerant in a less evaporable solvent which is heated by solar energy Pressurized vapor phase refrigerant is supplied to a main condenser and thence to a main evaporator and back to an absorber in which a low refrigerant content solution from the generator is converted to a high refrigerant content solution which is pumped to the generator for recirculation An electrically driven compressor supplies vapor phase refrigerant through the first auxiliary flow circuit including a condenser, a diaphragm-operated expansion valve, and a first auxiliary evaporator which is arranged to cool the main condenser The expansion valve is responsive to the vapor pressure of the generator to regulate the pressure of the auxiliary evaporator in a predetermined relationship with the pressure of the main condenser so that the pressure at which refrigerant is evaporated in the first auxiliary evaporator is lower than the pressure at which refrigerant is condensed in the main condenser The expansion valve is closed when the generator pressure is below the evaporation pressure of the main circuit to direct refrigerant from the compressor to a second auxiliary evaporator

Dual air-conditioner for motor-cars

Abstract: Disclosed is a dual air-conditioner for cars comprising an electromagnetic valve disposed in a refrigerant passage immediately downstream an outlet of an auxiliary evaporator for controlling the cross-sectional area of the passage, and an internal pressure balancing type expansion valve disposed in the refrigerant passage immediately upstream an inlet of the auxiliary evaporator. The passage cross-sectional area is controlled by the electromagnetic valve to control the pressure prevailing in the refrigerant passage between the expansion valve and electromagnetic valve so that the opening of the expansion valve is varied to regulate the flow rate of the refrigerant flowing into the auxiliary evaporator to thereby control the temperature of blow-off cooled air from the auxiliary evaporator.

Refrigeration system gravity defrost

Abstract: A reverse air cycle type heat pump is provided that utilizes a refrigeration system having a unidirection refrigerant flow wherein the condenser and evaporator retain their functions, but the air directed across them is redirected for different operations. The refrigeration system is provided with a secondary defrost circuit including a first conduit between the upper portion of the evaporator and the compressor casing and a second conduit having a valve which permits refrigerant flow to by-pass the expansion device only when compresssor operation terminates and the system pressure differential is equalized. This defrost circuit causes the relatively warm refrigerant in gaseous phase in the compressor to displace the relatively cold refrigerant in liquid phase in the evaporator with the flow continuing until the defrost process is completed.

Mechanical control system for preventing compressor lubrication pump cavitation in a refrigeration system

Abstract: A control system for operating a vapor compression refrigeration system to prevent oil pump cavitation during startup of the refrigeration system is disclosed. The control system includes a differential pressure switch which is connected on one side to a reservoir which is in fluidic communication with the refrigeration system evaporator or compressor suction line. The pressure switch is connected on its other side directly to the evaporator or compressor suction line. In operation, the reservoir fills with vaporous refrigerant from the refrigeration system when the refrigeration system is shut down and the vaporous refrigerant flows through a restrictor valve back to the refrigeration system at startup of the refrigeration system. The size of the reservoir and restrictor valve are selected so that the differential pressure switch is activated and a control is generated when too rapid a decrease in evaporator or compressor suction line pressure is detected. The control signal is supplied to a compressor guide vane control mechanism to adjust the system pulldown rate to prevent lubrication system cavitation.

Combined staged air conditioner and heat store

Abstract: Apparatus for carrying out a combined absorption and adsorption process comprising an adsorber (1) housing adsorbent (30) (e.g. 13× zeolite molecular sieve) and having means (2) for supplying heat to the adsorbent (30) from an external source, a vapor outlet in said adsorber connected by conduit (31) to a heat exchanger (4) capable of supplying heat to the working fluid of the generator (5) of an absorber system, means (19) for transferring heat to the generator (5) from the external source of heat, an expansion valve (6) connected by conduit (32) to said heat exchanger (4), an evaporator (7) connected by conduit (32) to said expansion valve (6) and also connected by conduit (35) to the adsorber (1), said absorber system comprising said generator (5) connected by conduit (8) to a condenser (9), an expansion valve (11) connected by conduit (40) to said condenser (9), an evaporator (7) connected by conduit to said expansion valve (11) and an absorber (13) connected by conduit (34) to said evaporator (7) and connected by two separate conduits (41, 42) to the generator (5), one conduit (42) having an expansion valve (15) therein.

Device for attaching electronical controlling device for motorcar

Abstract: PURPOSE:To enable to keep a control unit in the best condition at all times by a method wherein the control unit for an electronical controlling device is enclosed by a heat insulating portion and absorption of heat within the heat insulating portion is effected by a heat absorbing means based on a refrigerating cycle of a motorcar. CONSTITUTION:When a car is not cooled, a compressor 9 is driven by starting of an engine 4 and cooling medium is passed through a condensor 10, a receiver and a drier 11 and is changed into atomized cooling medium at low temperature and low pressure by an expansion valve 14, thereafter, is entered into an evaporator 16 through a pipe 17 to cool air within a heat insulating box 8 accommodating a computor 7 therewithin. On the other hand, when the car is cooled, a valve 12 for room cooling is opened and the cooling medium is supplied to the evaporator 15 in a cabin 2 through an expansion valve 13 from the receiver and the drier 11 in addition to the above-described refrigerating cycle. Accordingly, cooling of an internal portion of the heat insulating box 8 is effected simultaneously with a cooling of the cabin 2 and thus the computor 7 in the heat insulating box 8 may be kept in the best operating condition.

Method and apparatus for controlling operation of a thermostatic expansion valve.

Abstract: Method and apparatus for improving the superheat control of a thermostatic expansion valve metering refrigerant into a refrigeration system evaporator coil is disclosed in one exemplar embodiment having a superheat setting means (48) for establishing a required superheat, superheat determination means for measuring the superheat of the valve across the evaporator coil (32 and 34), differential means for comparing the measured superheat with the established superheat (56 or 66), and heating means (40) cooperating with the differential means for applying heat to the fluid-charged bulb of the valve when the measured superheat exceeds the established superheat. A heating control means (38) may also be included to control the heating means for increasing the rate of heating by the heating means when the measured superheat exceeds the required superheat, and for decreasing the rate of heating by the heating means when the required superheat exceeds the measured superheat.

Electronic control system for regulating startup operation of a compressor in a refrigeration system

Abstract: A method and control system for operating a vapor compression refrigeration system to prevent oil pump cavitation during startup of the refrigeration system is disclosed. The control system includes a temperature or pressure sensor located in the evaporator of the refrigeration system, a microprocessor, and an inlet guide vane control mechanism. During startup, the pressure of the gaseous refrigerant or the temperature of the liquid refrigerant in the evaporator of the refrigeration system, or compressor suction line pressure, is measured and an electrical signal corresponding to the measured pressure or temperature is processed by the microprocessor to determine the actual rate of pulldown of refrigerant pressure in the evaporator. The microprocessor compares the actual pulldown rate to a pulldown rate which has been predetermined to prevent compressor oil pump cavitation. The microprocessor controls the opening and closing of the inlet guide vanes to the compressor to adjust the flow of refrigerant to the compressor to achieve a pulldown rate which is approximately equal to the predetermined rate which prevents oil pump cavitation.

Method and device for controlling an air conditioning system

Abstract: A method of and a device for controlling an air conditioning system in which an air-flow proportioning door is positioned between a heater unit and a refrigerant evaporator unit and is movable into and out of an angular position shutting off the flow of air from the evaporator unit to the heater unit and in which a refrigerant compressor unit associated with the evaporator unit is operated to alternately stop and start depending upon the temperature of the air delivered from the evaporator unit, wherein the angular position of the air-flow proportioning door and the compressor stop and start temperatures are controlled depending upon a target blowoff temperature calculated from decided and detected temperatures of the space to be air conditioned and a detected ambient temperature so as to reduce the duty cycle of the compressor unit.

Solvent processing machine which saves energy by making use of refrigeration cycle

Abstract: PURPOSE:To achieve vaporization and liquefaction of solvents by a series of operation and make continuous operations easy by making combination use of refrigeration cycles to a processing machine for solvents provided with heat radiation surfaces and endothermic surfaces. CONSTITUTION:The heat radiating pipe 3' of a compressor 1 is enclosed in and conducted with the lower part of a solvent vessel 8, and futher the endothermic pipe 2 longitudinally provided in a solvent condensing vessel 9 corresponding to the condensing part 2 communicated with the solvent vessel 8 is circulated and disposed to the compressor 1 via an expansion valve 7. The solvent in the solvent vessel 8 is heated to evaporate by the refrigerant gas compressed and heated by the compressor 1, whereby the soils such as fats and oils mixed during the processing work are removed; in addition, the solvent is cooled to liquefy by the endothermic pipe 2 cooled by the pressure reduction of the expansion valve 7. This solvent is used for separation and purification of the solvent.

Device for the production of hot water by means of a heat pump, and method of operating this device.

Abstract: Device for the production of hot water by means of a heat pump, which has an evaporator for removing energy from a gaseous medium flowing through the latter, a condenser designed as a heat exchanger for hot water, and a compressor or pump for circulating the cooling agent, with an oil or gas-fired heating boiler (1) as part of the device, the evaporator (3) being arranged in the flue gas exhaust (2) of the heating boiler (1), a suction fan (4) after the evaporator (3) in terms of flow, and a controllable air inlet flap (5), for introducing outside air into the flue gas exhaust (2), before the evaporator (3) in terms of flow. The invention also relates to a method of operating said device. In this method, outside air only, a mixture of flue gas and outside air or flue gas only is sucked through the evaporator (3). The temperature of a hot water storage device associated with the device is constantly monitored. If the temperature falls below a given level, the heat pump is set in operation, the evaporator being flowed through by outside air if the temperature of the outside air does not fall below a given value. In the event of the outside air temperature falling below the set level or in the event of no or insufficient rise in temperature in the hot water storage device(s), the heating boiler is switched on and the inflow of the outside air is completely or partially interrupted.

Method and apparatus for controlling the temperature in the refrigerator chamber and freezer compartment of an absorption refrigerator

Abstract: In a refrigerator cabinet operated with an absorption refrigerating apparatus having an evaporator for cooling a refrigerating chamber and an evaporator for cooling a freezing chamber. The refrigerator condensate is supplied to the freezing evaporator and partly evaporated, while the residue flows by gravity into the refrigerating evaporator. At very low ambient temperature the freezing evaporator receives too little refrigerant, or else the refrigerating evaporator too much. This situation is avoided in that an evaporator part for cooling of the freezing chamber is supplied with refrigerant condensate at short intervals during periods when the thermostat for the refrigerating chamber is in an off position.

Heat pump heating system - has air cooler with defroster connected to heat accumulator between condenser and expansion valve

Abstract: The heat pump system is particularly intended for incorporation into a heating installation. It has an evaporator in the form of an air cooler, a condenser with a heat exchanger, and a refrigerating medium circuit passing through cooler and condenser. It contains a compressor in front of the condenser and an expansion valve in front of the cooler. The latter is equipped with a defroster. The defroster has a piping system (7) for a liquid heat-transfer medium integral with the cooler (1), and connected to a heat accumulator (8) in the refrigerating medium circuit (4) between the condenser (2) and expansion valve (6). The residual heat in the medium flowing from the condenser to the cooler is stored in the accumulator.

Capability control apparatus for cooling system having direct expansion type evaporator

Abstract: A capability control apparatus for a cooling system having a direct expansion type evaporator comprises a control valve mounted in a heating system for a generator for controlling an amount of heat to be given to the generator. Temperature sensors are mounted at inlet and outlet sides, respectively, of a cooling system for an absorber, and an arithmetic unit is connected to the temperature sensors and the control valve. The arithmetic unit calculates the amount of heat to be given to the generator based on signals transmitted from the temperature sensors to the unit and issues and transmits to the control valve a control signal for controlling the latter.