Showing papers on "Thermal expansion valve published in 1983"

Method and apparatus for controlling a refrigerant expansion valve in a refrigeration system

Abstract: A refrigeration system is disclosed which may have multiple compression and condenser stages, in which an electronic refrigerant expansion valve is controlled by the digital output of a microcomputer which adjust the expansion valve in response to a valve change signal which is a function of a fraction of the deviation of the sensed refrigerant superheat from a desired superheat added to a multiple of the computed rate of change of the refrigerant superheat.

Control device for refrigeration cycle

Abstract: A control device for refrigeration cycle constructed with a compressor, a condenser, an electrically operated expansion valve, an evaporator, and so forth, all being connected in series, wherein there are further provided a by-pass extending from an inlet or an outlet or both of the expansion valve upto an inlet of the compressor through a capillary tube; a first temperature sensor to sense a temperature of a cooling medium at the inlet of the compressor; a second temperature sensor to sense a temperature of the cooling medium within an intake tubing, through which the cooling medium is taken into the inlet of the compressor; and a control device which calculates a super-heat quantity of the cooling medium taken into the compressor on the basis of a difference between the detection outputs of the first and second temperature sensors, and controls a degree of opening of the electrically operated expansion valve, thereby enabling the refrigeration cycle to be operated at high efficiency and in an energy-saving mode.

Heat pump apparatus and method

Abstract: A temperature and humidity control system including a heat pump including a compressor, an evaporator and a condenser; vaporizable refrigerant contained in a closed circuit communicating with the compressor, evaporator and condenser, a regeneratable dessicant material, valve and conduit apparatus for selectably directing air into and communicating with the condenser, evaporator and dessicant material and including first apparatus operable in a cooling/dehumidifying mode for supplying air first to the evaporator and from the evaporator to the dessicant material, and from the dessicant material to a volume sought to be conditioned and second apparatus operable in a heating/humidifying mode for supplying air first to the condenser for heating of the air and from the condenser to the dessicant material for humidifying of the air to a volume sought to be conditioned.

Incrementally adjustable electronic expansion valve

Abstract: An incrementally adjustable electronic expansion valve for precisely controlling refrigerant flow through the valve is disclosed. Basically, the expansion valve includes a stepper motor, a sleeve member, and an orifice assembly. The sleeve member is incrementally moved over a slot(s) in the orifice assembly by operation of the stepper motor to control refrigerant flow between an inlet and an outlet of an expansion valve. A control system provides electronic digital control signals to the stepper motor to control operation of the motor in response to superheat of refrigerant flowing from an evaporator to a compressor of the refrigeration system. The electronic expansion valve may also include sealing means to substantially prevent refrigerant flow through the valve when the sleeve member is in its fully closed position.

Heat pump system

Abstract: A heat pump system in which the amount of opening of an expansion valve is set to an optimum value in dependence upon the inlet temperature of water undergoing heat exchange at a utilization side heat exchanger and an inlet temperature of air undergoing heat exchange at a non-utilization side heat exchanger In response to the sensed temperature values, a controller determines the optimum amount of valve opening so as to provide a maximum system capacity and efficiency The controller may be implemented with a microprocessor and a read-only memory In the read-only memory are stored data values representing optimum opening settings of the expansion valve corresponding to various values of the sensed inlet temperature of water at the utilization side heat exchanger and the inlet temperature of the air at the non-utilization side heat exchanger

Energy management system for chilled product vending machine

Abstract: A control circuit for cycling the evaporator fans on and off independently of the operation of the compressor of the refrigeration system is described. The evaporator fan is cycled on with the compressor and continues to run during the entire compressor ON cycle. A first timer causes the evaporator fan to run for an additional delay period following the cycling OFF of the compressor and the fans continue to blow air over the evaporator coil until the temperature of the evaporator coil is sufficiently above the freezing point of water (32° F., 0° C.). The fans are then cycled OFF. A second cycling timer is provided to intermittently cycle the evaporator fans on and off for predetermined short intervals following the above-described delay period, and during the time when the compressor is OFF. A third timer is provided to preclude freezing of the vended products and/or the evaporator coil when a vending machine is disposed in a below-freezing environment. This timer is enabled when the thermostatic temperature switch, which controls the compressor, opens, and will time out to cycle ON the evaporator fans for continuous operation for a predetermined period of time of the temperature switch remains open in excess of a predetermined period of time.

Electronic temperature control system

Abstract: A refrigeration system including a refrigeration control system for controlling the operation of the refrigeration system so as to insure that the temperature of the refrigerant discharged from the evaporator coil is above the saturation temperature. The refrigeration system includes at least one refrigerated display case having an evaporator within the primary air conduit and an expansion valve coupled to the inlet end of the evaporator coil. The control system includes: a pressure sensor arranged within the refrigerant discharge line, i.e. suction line to compressor, from the evaporator coil; a first temperature sensor arranged at the air discharge side of the evaporator coil for sensing the temperature (T 1 ) of the air that has passed over the evaporator coil, a second temperature sensor arranged adjacent to the refrigerant discharge end of the evaporator coil for measuring the temperature (T 2 ) of the refrigerant discharged from the evaporator coil and a third temperature sensor arranged adjacent the inlet end of the evaporator coil for sensing the temperature (T 3 ) of the refrigerant flowing into the evaporator coil. Based upon a comparison of temperatures T 1 , T 2 and T 3 a series of output control signals are provided for controlling the operation of the expansion valve.

Liquid temperature regulator

Abstract: A liquid temperature regulator is disclosed which includes a refrigeration cycle comprising a compressor, a condenser and an evaporator, a liquid tank containing a kind of liquid to be temperature-controlled and the evaporator, and inlet and outlet tubes for feeding the liquid into the tank and feeding out the liquid from the tank. The regulator is provided with a by-pass path for the connection of the outlet and inlet ports of the compressor, a valve for opening and closing the valve and a temperature controller for controlling the valve according to the temperature of the liquid. The by-pass path is closed when the liquid temperature is higher than a preset value and it is closed when the liquid temperature is lower than the value.

Cooling system having combination of compression and absorption type units

Abstract: A cooling system including a compression refrigeration unit and an absorption refrigeration unit, with the compression refrigeration unit including a compressor having a capacity control mechanism; a condenser for cooling and condensing a compressed refrigerant gas through a heat exchange between the refrigerant gas and a cooling medium circulated through the condenser; and an evaporator into which the condensed refrigerant is introduced through an expansion means so as to be evaporated and cool a medium by the latent heat derived from evaporation. The absorption refrigeration unit includes a generator having a capacity control mechanism for heating a solution to generate a vapor of a refrigerant and a strong solution; a condenser in which the vapor of refrigerant generated in the generator is cooled and condensed an evaporator in which the refrigerant in the condenser is evaporated and cools a medium to be cooled by latent heat from the evaporation; an absorber in which the vapor of refrigerant is absorbed by the strong solution generated and forms a weak solution; and a pump for feeding the weak solution to the generator. The compression refrigeration unit and the absorption refrigeration unit are connected so that at least the medium to be cooled and the cooling medium first flows into the compression refrigeration unit and then into the absorption refrigeration unit.

Refrigerating systems having differential valve to control condenser outflow

Abstract: In a refrigerating system comprising a compressor, a condenser, a capillary tube, and an evaporator, there are provided a check valve on an inlet side of the condenser for preventing a reverse flow of refrigerant from the condenser to the compressor, and a differential valve connected to a delivery side of the condenser. One port of the differential valve is connected with the delivery side of the compressor, so that the differential valve interrupts the flow of the refrigerant from the condenser to the capillary tube upon interruption of the operation of the compressor thereby to improve the operational efficiency of the refrigerating system when the system is started again.

Valve for liquid injection into a refrigerant evaporator

Abstract: The invention relates to a valve assembly for a refrigeration plant of the kind used for controlling the flow of refrigerant from the evaporator to the compressor. The closure member for the valve unit is controlled directly or indirectly by a movable wall of an expansible chamber filled with a refrigerant medium having vapor and liquid phases. The pressure exerted by the vapor phase of the medium provides a bias in a valve opening direction which is directly related to the temperature of the liquid phase and is opposed by a spring bias in the valve closing direction. A heat transfer element such as a heating resistor in the liquid phase is heated or allowed to cool in a controlled manner by an external control unit. A temperature responsive sensor element in the liquid phase of the medium is part of a feedback system for the control unit which allows a selected temperature to be maintained in the chamber which results in a desired constant pressure in a valve opening direction to be maintained in a chamber. A control unit has an evaporator parameter input branch and a second input branch for the feedback temperature sensing element. The control unit has an output for heating the heating resistor in the expansible chamber and a summating section for varying the relative effects of the input branches on the output.

Absorption type heat pump device

Abstract: An absorption type heat pump device including a generator for generating refrigerant vapor, a condenser, an evaporator, an expansion valve, an absorber, a solution pump, a passage member for leading strong solution from the generator to the absorber, and a heat exchanger. The heat exchanger and/or the passage member is provided with a portion in which a pressure drop is made larger than a drop in equilibrium pressure resulting from a temperature drop so as to perform flow control of the strong solution.

Air conditioning plant

Abstract: 1. Air conditioning system with compressor (1), condenser (2), expansion valve (3), distributor (11, 12, 13) and evaporator (4) arranged in a coolant circuit, the outlets (11.1, 12.1, 13.1, ...) of the distributor being arranged evenly distributed over inlets (4.1, 4.2, 4.3, ...) of the evaporator (4) and controllable solenoid valves (6, 7, 8) being provided for influencing the coolant flow between compressor (1) and evaporator (4), characterized in that the outlet of the expansion valve (3) is connected to the inlets of a number of solenoid valves (6, 7, 8) and each solenoid valve is connected to a distributor (11, 12, 13), the expansion valve (3) is controlled via a thermostat (15) arranged at the outlet of the evaporator (4) and pressure switches (17, 18) arranged between compressor (1) and condenser (2) act on the solenoid valves (6, 7, 8) and partial areas of the evaporator can be disconnected via the assigned solenoid valves (6, 7, 8) as overload protection for the condenser (2).

Computer cooling system

Abstract: A computer cooling system has gaseous refrigerant compressed in a compressor and delivered to a first stage condenser. The first stage condenser includes a heat exchanger through which return coolant from the building heating system circulates to partially condense the gaseous refrigerant. The partially condensed refrigerant is directed to a second stage condenser wherein a portion of the refrigerant is diverted and flashed through an expansion valve into the second stage condenser to fully condense the nondiverted portion of the refrigerant before delivering it to the cooling coils of the computer. A pressure regulator valve controls the pressure and temperature of the diverted refrigerant in the second stage condenser to ensure that the nondiverted refrigerant is fully condensed. The used diverted refrigerant is discharged from the second stage condenser through the pressure regulator valve into an accumulator which also collects return coolant from the cooling coils of the computer. The used coolant is delivered from the accumulator back to the compressor through a main return conduit.

Refrigerant distributor for the evaporator of a refrigerator or heat pump

Abstract: Refrigerant distributor for an evaporator, having several adjacently arranged inlet openings for a refrigerant, of a refrigerator or heat pump, consisting of a distributor head which is to be attached to the evaporator and which has a longitudinal bore and several crossbores extending from this and arranged at the spacing of the inlet openings (Fig. 2).

Heat-pump control

Abstract: An air-to-water heat pump has been designed to operate with a variable-speed compressor, an electrically driven motorised expansion valve and variable-input air mass flow rate; all of these are supported by a microcomputer-based control and instrumentation system. The paper develops the control algorithms which provide for independent control of the valve, compressor speed and air mass flow rate so that the refrigerant pressure across the evaporator can be maintained to ensure maximum heat transfer occurs in the evaporator. Experimental results demonstrate that the efficiency of the heat pump can be improved by the on-line control system.

Heat source device for water heat-source heat pump type air-conditioning unit

Abstract: PURPOSE:To maintain the cooling efficiency of heat-source water, and to improve heating efficiency by cooling heat-source water introduced to a water heat-source heat pump type air conditioner by a cooling tower and heating said water by a condenser of a refrigeration cycle. CONSTITUTION:The water heat-source type air-conditioning units 20 are communicated with the heat source device 21 consisting of the cooling tower 22, a heat accumulating tank 23, a circulating pump 24 and a piping 25. The cooling tower 22 is provided with a cooling fan 26, an evaporator 27, a water spray pipe 28, a cooling coil 29, a water tank 30 and a receiving chamber 31 from an upper end, the water spray pipe 28 and the water tank 30 are connected through a pump 32, and a compressor 33, the condenser 34 and an expansion valve 35 are arranged into the receiving chamber 31, and communicated with the evaporator 27. The draw-out sides of the units 20 are branched partially to the cooling coil 29 and joined in a three-way valve 37, and communicated with the heat accumulating tank 23 through a heat exchange section 32 heat-exchanging with the condenser 34.

Refrigerated air conditioning system using diaphragm pump

Abstract: A refrigeration system includes a first evaporator for evaporating a first refrigerant. The pressure exerted by the evaporated first refrigerant is used to drive a gas-driven diaphragm pump. The first refrigerant leaving the diaphragm pump is cooled and condensed by a first condenser which receives evaporatively cooled air. A motor-driven pump circulates the first refrigerant in liquid form from the first condenser back to the first evaporator. The diaphragm pump compresses a second refrigerant in gaseous form, and the compressed second refrigerant gas is circulated to a second condenser for liquification. The liquified second refrigerant is circulated to a second evaporator for absorbing heat from the medium to be refrigerated, causing the second refrigerant to evaporate to a low pressure gas which is returned to the diaphragm pump.

Water heating device of heat pump type

Abstract: Provided is a water heating device of heat pump type which comprises a compressor, an evaporator, a duplex-pipe condenser and a blower means, characterized in that the blower means and the compressor are laid horizontally and, at the back of this arrangement, the evaporator is disposed, and the duplex-pipe condenser wound in a slender elliptic form is disposed on tops of the evaporator and blower means.

Energy conservation type heat pump air conditioner

Abstract: PURPOSE:To economize energy for air conditioning by connecting a water-cooled condenser and an air condenser in series as condensers and installing them and adjusting an indoor temperature by means of a flow-rate regulating valve regulating the flow rate of the water of the water-cooled condenser. CONSTITUTION:A heating means reheating air by means of a compressor 1, the condensers 2, 3, an expansion valve 4, an evaporator 5 and a heater and a controlling means controlling said heater by means of a thermostat 7 in order to adjust the indoor temperature are mounted. In the air conditioner, said condensers are divided into the primary condenser 2, in which a refrigerant is cooled by water and condensed, and the secondary condenser 3 in which a refrigerant is cooled by air and condensed, and connected in series. Said heating means and controlling means become a water-quantity regulating means adjusting the flow rate of cooling water by means of the water-quantity regulating valve 6 in the primary condenser 2 and a controlling means controlling the valve 6 by means of the thermostat 7 in order to adjust the indoor temperature.

Heat pump apparatus

Abstract: A heat pump apparatus has a main refrigerant circuit constituted by a closed loop including a compressor, condenser, gas-liquid separator, pressure reducer such as an expansion valve, and an evaporator. A shunting refrigerant line having a compressor, condenser and a pressure reducer means shunts from the gaseous phase portion of the gas-liquid separator of the main refrigerant circuit and merges in the evaporator of the main refrigerant circuit. The shunting refrigerant line may be constructed to have one or more compression stages.

Air conditioning equipment for car

Abstract: PURPOSE:To enhance stability and controllability of discharged air temperature by supplying an air heater, which is arranged in the main body unit of an air conditioning equipment, with engine cooling water which is discharged from a flow-rate variable motor driven pump and the flow-rate of which is controlled by a flow-rate variable electromagnetic valve. CONSTITUTION:A refrigerating circuit is formed by successively connecting together through piping, a compressor 16, which is driven by power of an engine 13 via a transmitting means including a pulley 14 and an electromagnetic clutch 15, a condenser 17, an expansion valve 18 and an evaporator 12, which is placed in a main body unit 6 of an air conditioning equipment. An air heater 19 is installed downstream the evaporator 12 in the main body unit 6, and engine cooling water is circulated by operation of a flow-rate variable, motor-driven pump 24. The pump 24 is controlled by means of a motor 25 in a stepless or a stepped manner. A flow-rate variable motor-driven valve 26 is interbosed in the engine cooling water supply pipe passage leading to the air heater 19. The valve 26 as well as the said clutch 15 and the said motor 25 are controlled by a computer 28.

Combination of solar cell and heat pump using solar heat and air as heat source

Abstract: PURPOSE:To obtain a highly efficient system, by a method wherein a solar cell layer is provided on the surface of an exterior heat-collecting panel for a heat pump using the solar heat and air as heat sources, and a compressor for a refrigerant used for the heat pump is selectively driven by electric power obtained by thesolar cell layer. CONSTITUTION:The heat-collecting panel 1 is formed, for example, by extruding Al, and is provided with a refrigerant passage 3 at a central part thereof and the solar cell layer 2 on the surface thereof. The refrigerant is circulated into the passage 3 through a pipe 4, in which an expansion valve 5, a heat exchanger 6 and the compressor 7 are provided. When the sunshine is available, electric power is taken out from the solar cell layer 5 of the heat-collecting panel 1, is fed to an inverter 11 through a charging controller 10 by a wiring 9, is converted into AC power by the inverter 11, and is then used to drive a compressor-driving motor 8 through a change-over switch 14. When the sunshine is not available, electric power from a battery 12 or a commercial power source 15 is used, in which case the panel 1 functions as an efficient heat pump with air as a heat source.

Heat pump type water heating equipment

Abstract: PURPOSE:To efficiently heat the water on a single refrigerating cycle by a process wherein the water heating process is divided into two stages: in the first stage, medium temperature water is produced and stored in an heat accumulator; in the second stage, said medium temperature water is heated in order to get high temperature water. CONSTITUTION:The refrigerating cycle consists of a compressor 101, a condenser 102, an expansion valve 103 and an air heat source type evaporator 104. A hot water passage connecting to said condenser 102 consists of pipes 119, 118, which is provided with a pump 110 and to which a feed water pipe 121 is connected through a valve 111 and also to which a low temperature heat accumulator 108 and a high temperature heat accumulator 109 are connected in parallel through valves 112 and 115 respectively, and a pipe 120, to which the low temperature heat accumulator 108 and the high temperature heat accumulator 109 are connected in parallel through valves 113 and 116 respectively. Owing to the arrangement as mentioned above, the medium temperature water stored in the low temperature heat accumulator 108 is recirculated to the condenser 102 in orde to be turned into high temperature water and stored in the high temperature heat accumulator 109.

Air conditioner for automobile

Abstract: PURPOSE:To reduce the load on a compressor, by providing a room cooling evaporator with a superheat control valve capable of changing the degree of superheat of a coolant, to reduce the load on the cooling evaporator at the time of reheating. CONSTITUTION:An evaporator is divided into a compact evaporator E1 for dehumidification and an evaporator E2 exclusive for room cooling. An expansion valve EV2 capable of changing the degree of superheat of a coolant in the room cooling evaporator E2 is provided therefor to gradually decrease the cooling capacity of the evaporator E2 with the operation of a temperature control lever 8 toward a position ''hot'', namely, greatly decrease the cooling capacity by a quantity reheated by a heater 3 in a reheating zone, to reduce the load on a compressor by the quantity of the decrease in the cooling capacity.

Heating or cooling arrangement with a heat pump

Abstract: In a heating or cooling arrangement with at least two closed circuits of a working medium, the first closed circuit is formed by a heat pump which consists of a compressor (1), condenser (2), expansion valve (3) and an evaporator (4). The second closed circuit is formed from a pipe coil which is in heat exchange with the evaporator (4) and embedded in the earth. In this case, the pipe coil is designed as a pipe coil (5a, 5b) which is mounted on a frame (6), is introduced into a borehole (7) in the earth and is back-filled with earth. The pipe coil takes up only a small area and can, with a drilling device, even be introduced into gardens which are already planted.

Intake air cooling device of engine with supercharger

Abstract: PURPOSE:To cool supercharged air effectively without the larger-sized evaporator and the condenser of a refrigeration unit by installing the evaporator of the refrigeration unit in the intak air path located in lower stream of a cooler. CONSTITUTION:Supercharged air which is sucked in through an air cleaner 9 and compressed by the compressor 11 of a turbo-supercharger 10, is cooled by a cooler 12. When the temperature of the supercharged air cooled by the cooler 12 is detected by the first temperature-sensor 25, and further when the detected temperature is over 70 deg.C, a compressor 19 is driven by a magnetic clutch 23 connected thereto and a refrigeration unit 16 is operated. In a surge tank 13, supercharged air pre-cooled in the cooler 12 is subjected to heat exchange with the refrigerant in the evaporator 17 of the refrigeration unit 16, and further is cooled by evaporating the refrigerant. The temperature of supercharged air cooled in the surge tank 13 is detected by the 2nd temperature sensor 26, and the feedback control is performed so that the opening of an expansion valve 22 varies in accordance with the temperature.

Claude and Joule-Brayton Systems

Abstract: Here we consider a family of cryocoolers using recuperative heat exchangers and achieving cryogenic temperatures by expanding gas in an engine thereby producing work. When the gaseous working fluid is to be liquefied it is customary for the final stage of expansion to be done with a Joule-Thomson expansion valve. Systems with expansion engines and a final Joule-Thomson expansion are called Claude cycle liquefiers. When the system is used as a refrigerator rather than a liquefier the final Joule-Thomson stage is not included and all the expansion occurs in expansion engines. These are called Joule-Brayton cycle refrigerators.

Heating device utilizing solar heat

Abstract: PURPOSE:To enhance utilization of a titled device, by a method wherein, in a device in which hot water heated by a collector is stowed in a heat accumulating tank, and a radiator is heated by hot water in said tank, a heat pump cycle is placed, and a condenser is, in a relation of heat exchange, combined with a radiator circuit. CONSTITUTION:In a device in which hot water, being increased in temperature by a collector 2, is stowed by feeding it in a heat accumulating tank 1 through operation of a circulating pump 5, hot water in the tank 1 is then fed to a radiator 3, and hot air is blowed out through operation of a fan 4, a heat pump cycle is mounted. Or, the device is constituted such that a condenser 12 is placed in a relation of heat exchange and in the proximity of a piping at the output side of the radiator 3, a coolant discharged from a compressor 11 is fed, and heat is applied to hot water in a radiator circuit 8. Meanwhile, the coolant itself is condensed, and is led to an evaporator 14 through an expansion valve 13. The evaporator 14 is installed such that hot water in the heat accumulating tank 1 serves as a heat source, and the radiator circuit 8 is adapted to be actuated by the condenser 12 serving as a heat source through switching of a 3-way valve 9.