Showing papers on "Thermal expansion valve published in 1976"

Control system for refrigeration apparatus

Abstract: A controlled space is maintained at a desired set point temperature by adjusting the refrigerant temperature at the evaporator outlet in a refrigeration system, thereby controlling the evaporator effectiveness or capacity which is inversely proportional to the outlet temperature. When the space temperature tends to vary from the desired set point due to a changing heat load, the control system automatically changes the refrigerant flow through the evaporator to establish the evaporator outlet temperature at the control point required to maintain the controlled space at the desired temperature. More specifically, in response to a space temperature increase, the flow rate of the refrigerant increases; and in response to a drop below the set point, the refrigerant flow decreases. Such control of the flow rate is achieved by varying the displacement of a controlled displacement compressor included in the refrigeration system. When the heat load on the evaporator is constant, the refrigerant flow is controlled in order to hold the evaporator outlet temperature fixed at the required control point.

Movable expansion valve

Abstract: An expansion device for use in a reversible vapor compression refrigeration cycle for producing, upon demand, either heating or cooling. Two devices are mounted in opposed relationship in a supply line carrying refrigerant between a first heat exchanger and a second heat exchanger. Each expansion device includes a body having a flow passage therein opening into an expanded chamber. A free-floating piston is slidably mounted in the chamber and is moved to a first position when refrigerant is passed through the line in a first direction and to a second position when the direction of flow is reversed. A centrally located metering port passes through the piston while fluted channels are formed in its outer periphery. When in the first position, the fluted channels are closed against one side wall of the chamber and refrigerant is throttled through the metering port from the high pressure exchanger (condenser) into the low pressure exchanger (evaporator). Reversing the direction of refrigerant flow causes the piston to be moved into the second position wherein the fluted channels are opened to the supply line to allow an unrestricted flow of refrigerant about the piston.

Multiple stage expansion valve for an automotive air conditioning system

Abstract: A multiple stage expansion valve for use in an air conditioning system for an automotive vehicle including multiple stage flow control orifices located between a refrigerant condenser and a refrigerant evaporator, the high pressure side of the refrigerant gas compressor being in fluid communication with the inlet side of the condenser, the low pressure side of the compressor being connected to the outlet side of the evaporator through a suction throttling valve device, said expansion device comprising multiple stage orifice valves defined in part by a movable piston that responds to the pressure differential across the expansion device to establish optimum refrigerant flow through the air conditioning system during operation at high load, for establishing a relatively high fluid flow restriction during operation at low and moderate loads, and for establishing a moderate fluid flow restriction during operation at high loads and low compressor speeds.

Refrigeration control system for optimum demand operation

Abstract: A control sysem for controlling a plurality of refrigeration compressors has an input circuit for receiving a plurality of control signals from control devices for a plurality of evaporators connected to the refrigeration compressors with means for controlling the control signal of the evaporator having the greatest load to control the total operating capacity of the refrigeration compressors. Each of the input circuits has means for rendering the control signal input ineffective from a particular evaporator when the evaporator is in a defrosting cycle to allow the signal from the evaporator having the greatest load control the operating capacity of the refrigeration compressors.

Coolant circulation in refrigerator of cold-storage plant - controlled drive-motor speeds maintain constant temperature at expansion valve

Abstract: Method for controlling the coolant circulation in a compressor-refrigerated cold storage plant, so as to maintain a constant temperature (or, equivalently, pressure) at the expansion valve gauges uses variable-speed motors for the condenser fan and/or compressor drive, or preferably, under computer control - both of them and the cold-store fan drive also. The speed of the condenser fan is controlled to provide the same output temperature in all atmospheric conditions. The compressor speed must change when fresh food is put into the store. The draught through the evaporator - i.e., the cold store itself - is held within limits, keeping the air moving without causing too much drying.

Control system for maximizing the efficiency of an evaporator coil

Abstract: A method and apparatus for controlling the operation of a refrigeration system, for example, is provided. Refrigeration systems commonly include a compressor, an evaporator coil, a condensing coil and an expansion valve inserted in the refrigeration line between the evaporator coil and the condensing coil. In the preferred form of the invention, an electrically controlled expansion valve is operatively connected to control means. The control means includes a pair of sensors. The control means is used to control expansion valve operation so that evaporator operation is maximized, regardless of load on the system. Control is accomplished, in one embodiment, by sensing the temperature along two points of the evaporating coil, and using the control means to maintain a predetermined temperature relationship between the two points. In other embodiments of the invention, the control means is utilized to regulate system operation by sensing a compressor sump temperature, ambient air, or any other parameter bearing an overall system performance.

Portable water distillation apparatus

Abstract: A distillation apparatus having an evaporator for vaporizing liquid to be distilled, a substantially vertically disposed up-and-down flowing condenser in communication with the evaporator for condensing vaporized liquid received from the evaporator, and a heater associated with the evaporator for applying heat to and vaporizing fluid in the evaporator. The condenser feeds liquid into the evaporator so as to maintain a constant level of liquid in the evaporator at the highest normal point of flow of liquid in the condenser. The vapor travels downwardly through the condenser so as to become condensed at the bottom of the condenser where a distilled water output is provided for discharge of the distillate.

Freeze-up prevention device for a heat pump

Abstract: The present invention relates to heat pumps which include a freeze-up prevention device for use during the heating cycle. The heat pump consists of the normal compressor which connects by means of a four-way valve to an inside coil and an outside coil. An expansion valve and appropriate check valve allow the flow of refrigerant between the inside and outside coils. During the heating cycle, the inside coil is the condenser and the outside is the evaporator. The freeze-up prevention device is a small insertable unit immediately prior to the evaporator which allows the refrigerant to flow therethrough. The insertable unit has a heating element operable by a thermostat attached to the outside coils with the thermostat closing a switch to allow current to flow to the heating element when an icing condition is sensed. The insertable unit, via the heating element, transmits heat directly to the refrigerant thereby preventing freeze-up of the evaporator coil.

Installation for heating a fluid, preferably water, in a conventional central heating system, using the waste heat produced by a number of refrigerators

Abstract: There is provided a heat pump installation for the heating of tap water and for room heating purposes e.g., associated office spaces in large warehouses where a number of refrigerators are operating. The heat pump receives its input heat from the heat liberated by the refrigerators. In order to protect the refrigerators from the influence of the heat pump, and in order to accomplish a smooth operation of the heat pump, the installation according to this invention exhibits the features, that the evaporator device of the heat pump is arranged in the form of parallel-coupled evaporator units each of which is assigned an expansion valve controlled by the refrigerant pressure at the unit outlet; That a by-pass line containing a valve which opens when the outlet pressure reduces, is arranged between the high-pressure side of the heat pump compressor and the refrigerant circuit of the heat pump, following the evaporator units; That another by-pass line with a valve controlled by the pressure or temperature at the inlet side of the compressor, is arranged in parallel with the evaporator units of the heat pump; And that each evaporator unit of the heat heat pump is arranged in a heat-exchanging relationship with its particular first condensor unit in each condensor device of the refrigerators said condensor devices comprising in each case at least one additional condensor unit for the dissipation of the recidual heat, for example to the outdoor air, a third by-pass line being arranged in parallel with the second condensor unit, and a control means being arranged to control the flow distribution between the condensor units as a function of the desired refrigerant pressure after the condensor device.

Air cooled centrifugal refrigeration machine with provision to prevent evaporator freezing

Abstract: An air cooled centrifugal refrigeration machine is shown having an automatic shut-off valve in the liquid line to prevent natural circulation of refrigerant at low outdoor ambient temperatures that otherwise would cause freezing of the water in the evaporator.

Noise reduction arrangement for a compressor type refrigerator

Abstract: A construction in a compressor-type refrigerator which is arranged between the condenser and the evaporator and adjacent to where a flow restricting tube connects to the evaporator tube whereby the noise level is considerably reduced when the refrigerant flows into the evaporator tube.

Self operating excess refrigerant storage system for a heat pump

Abstract: Excess refrigerant is collected within a refrigerant pot surrounding a portion of the return conduit connecting the outdoor coil operating as an evaporator during a heat pump heating cycle to the compressor creating a reduced pressure temperature relationship within the pot cavity causing the migration of liquid refrigerant through a small diameter tube connecting the pot to the liquid line leading from the indoor coil to the outdoor coil at a point upstream of the outdoor coil expansion valve.

Defrosting system in a compression refrigerator

Abstract: Disclosed is an improved defrosting system in a compression refrigerator. According to this invention there is provided a defrosting system in which the liquid-phase refrigerant is extracted from upstream of the expansion valve to a defrosting tank which is maintained at an elevated temperature high enough to cause the refrigerant to change from the liquid to vapor phase, and the now vapor-phase refrigerant is supplied to the evaporator where the refrigerant lose its heat in changing from the vapor to liquid phase, and the now liquid-phase refrigerant returns to the defrosting tank. The refrigerant circulates until the evaporator has been completely defrosted.

Heat sink temperature stabilized evaporator coil

Abstract: A temperature stabilized refrigeration evaporator coil for use with a mechanical refrigeration compressor and condenser is disclosed which gathers and retains its own latent heat sink material to temperature stabilize its air heat exchange surfaces. The evaporator is adapted to condense water from the air it is cooling, and to retain an adequate quantity of that water to employ as a liquid-solid phase change, latent heat sink to temperature stabilize the evaporator, air heat exchange surfaces, so that they do not become excessively cold during the on cycle of the compressor, and so that they do not become excessively warm during extended periods of the off cycle of the compressor. The unit is adapted to allow its manufacture, sale and transportation in a dry condition without the additional weight and spillage problems of the heat sink water, and to assure the user of the unit that it will operate properly even though he neglects to initially charge it, or to later maintain it with the proper quantity of heat sink water.

Suction accumulator for refrigeration systems

Abstract: A suction accumulator for refrigeration systems having a tank with an inlet fitting for conveying it to refrigerant vapor from the evaporator which is mixed with oil and at times with liquid refrigerant. The tank has an outlet fitting for conveying away the refrigerant vapor from which the oil and liquid refrigerant have been separated. An oil return conduit is located underneath the tank. One end of the oil return conduit is connected into the bottom of the tank; the other end to the outlet fitting of the accumulator. Located within this oil return conduit is a thermostatic expansion valve whose bulb is located on the oil return conduit between the tank and the expansion valve. This bulb senses low superheat when liquid refrigerant is in the tank and in the conduit, and causes the expansion valve to close when liquid refrigerant is present, preventing the flow of large amounts of the liquid refrigerant into the outlet conduit. When no liquid refrigerant, but only oil, is present, the bulb senses superheat and causes the expansion valve to open, allowing relatively free flow of the oil from the accumulator tank into the outlet conduit. Another discriminating device is a float whose specific gravity is such that it floats in liquid halocarbon but sinks in oil.

Heat pump assembly

Abstract: An assembly for dehumidifying air, such as in swimming pool enclosures, comprises a heat pump system including a compressor, an evaporator, a condenser and a thermostatic expansion valve. A brine liquid system forms a closed loop through which brine liquid is circulated, and the brine is maintained at a temperature below the dew point of the air by, for instance, circulating the brine through a pipe system in the earth's crust. A cooling surface is in heat-conducting communication with the evaporator and with the brine liquid. The air to be dehumidified is passed over the cooling surface to be dehumidified, and over the condenser for selective heating. The compressor can be run selectively when heating is desired, or when needed to keep down the temperature of the brine liquid. A heat exchanger connectable in series with the condenser can function to heat the water of the pool.

Heat pump for optional heating or cooling - has three way valves for connecting circulation to evaporator or condenser

Abstract: The heat pump system has a compressor, condenser, pressure reducer valve and evaporator. The system has a changeover arrangement for optional heating or cooling especially of dwelling rooms for the purpose of air conditioning. The refrigerant circuit continues operating without modifications on heating or for cooling purposes. The supply flow (15) and the return flow (13) are connected optionally to the heat exchangers (10) of the dwelling room for heating and cooling purposes by means of the three way valves (6, 7, 8, 9). The connection is made optionally to the evaporator (5) or to the condenser (3). The heat absorbed on cooling the room is supplied to a water storage heater (16) whose temp. is regulated by the ground water heating.

Solar powered cooling apparatus

Abstract: Solar powered cooling apparatus is disclosed in which liquid refrigerant is vaporized in a collector/evaporator by solar radiations concentrated by a reflector, and the pressurized vapors operate an aspirator to reduce the pressure in an evaporator containing the same liquid refrigerant to cool the same. The mixture of vapors leaving the aspirator are condensed in a higher positioned condenser and supplied to a gathering vessel from which the liquid refrigerant is forced back into the collector/evaporator with the assist of pressurized vapors periodically withdrawn from the collector/evaporator.

Multistation refrigeration system

Abstract: A closed cycle refrigeration (CCR) system is disclosed for providing cooling at different temperatures to different parts of a maser. The CCR includes a first station for cooling the maser's parts, except the amplifier portion, to 4.5° K. The CCR further includes means with a 3.0° K station for cooling the maser's amplifier to 3.0° K and, thereby, increases the maser's gain and/or bandwidth by a significant factor. The means which provide the 3.0° K cooling include a pressure regulator, heat exchangers, an expansion valve, and a vacuum pump, which coact to cause helium, provided from a compressor, to liquefy and thereafter expand so as to vaporize. The heat of vaporization for the helium is provided by the maser amplifier, which is thereby cooled to 3.0° K.

Fan control circuit for air conditioner

Abstract: A control circuit for a room air conditioner includes two temperature sensing devices and an associated switch network which operate to de-energize the evaporator fan upon de-energization of the compressor but, as the temperature of the room air subsequently rises, cause the evaporator fan to be energized prior to re-energization of the compressor. The evaporator housing and temperature sensing devices are arranged such that during operation of the evaporator fan one of the devices senses the temperature of air entering the evaporator while the other senses the temperature of air leaving the evaporator, but during periods when the evaporator fan is off the device which formerly sensed the temperature of air leaving the evaporator operates to sense the temperature of room air.

Air conditioning method and apparatus with humidifier

Abstract: The combination with an air conditioning system including compressor, condenser and evaporator, with a humidifier for humidifying conditioned air and a heat exchanger for transferring heat between hot refrigerant of the air conditioning system and water supplied to the humidifier.

Dual liquid delivery and separation apparatus and process

Abstract: A refrigerant delivery and separation apparatus and a process for delivering refrigerant at evaporator temperature to an evaporator at a predetermined pressure which is less than the pressure at the receiver, and simultaneously separating refrigerant liquid and vapor which is discharged from the evaporator. The apparatus includes a pair of tanks connected by time operated control members to conventional refrigeration equipment so that one tank is pumping liquid refrigerant to an evaporator at a predetermined pressure while the other tank is separating liquid and vapor refrigerant substantially at evaporator pressure.

Defrosting system for refrigerator evaporator with heater - compares reference temp. curves with evaporator temp. variation for heater switching

Abstract: The evaporator of a refrigerator and deep freeze arrangement uses a heating system for defrosting. The heating performance is controlled during the stationary period of the refrigeration unit in relation to the environment temp. The analogue control circuit of the system can be readily converted into digital form. The temp. of the evaporator is sensed and digitised by an analogue to digital converter. The digital temp. curve, used as a reference curve is stored and compared by a comparator with the temp. variation curve of the evaporator. A timing generator is used for the synchronisation of this comparison process. This generator starts only when the compressor is stationary. The digital outlet signal of the comparator is used for switching the heating resistor on the evaporator on or off.

Heat pump for space heating - has additional circuit and controls to provide domestic hot water through calorifier

Abstract: A heat pump consists of an evaporator, a compressor, a condenser and an expansion valve. It takes heat from a pool or stream and delivers it to primary water circulating in a heating system. A branch of the primary circuit leads through a three way valve to the heating coil of a colorifier in which secondary domestic hot water is heated. A second branch of the primary hot water circuit leads through a supplementary boiler to the inlet of the three way valve from the third outlet of which the primary water is taken to the space heaters. The three way valve is controlled by a thermostat in the calorifier to give priority to the domestic hot water demand.

Kojundono ekitaisansooyobi ekitaichitsusono seiho

Abstract: 1500610 Separating air NUOVO PIGNONE SpA 8 July 1975 [12 July 1974] 28762/75 Heading F4P A process of obtaining liquefied O 2 and/or N 2 comprises cooling feed air 20 in exchanger 1, partially liquefying the cooled air 21 by expanding it through a first turbine 4 and/or an expansion valve 2, and subjecting the partially liquefied air 23 to fractionation in a column 5 form which liquefied O 2 and/or N 2 can be withdrawn, the N 2 being withdrawn via line 24 and being used to cool feed air in exchanger 1 after which it is led via line 26 for expansion in a second turbine 10 driving a load 12, the pressure of the cooled air upstream of turbine 4 and/or valve 2 being 1 to 3 atmospheres greater than that of column 5. All or part of cooled air 21, depending on the degree of closure of valve 2, is slightly preheated in exchanger 3 in heat exchange with a portion of the N 2 from line 26 which has been compressed at 9. The N 2 is preheated at 6, before passing to exchanger 1, in heat exchange with part of the cooled air 21 which then passes via line 32, valve 13 and line 33 to column 5. After leaving turbine 10, the N 2 returns via line 30, exchanger 6 and line 30 to exchanger 1. Exchanger 3 may be omitted (Fig. 2, not shown), air drawn from further down column 5 may be employed as coolant for exchanger 1 (Figs. 3 and 4, not shown), and compressor 9 may be dispensed with (Figs. 5 and 6, not shown).

Method to transfer heat or refrigerant and heat pump for practical application of this method

Abstract: The invention relates to a method for the transfer of heat or refrigerant between two separate flows of fluid, by means of a heat pump incorporating a refrigeration cycle. The refrigeration cycle comprises an evaporator, a compressor, a condenser and a regulating valve, the evaporator and the condenser being adapted for heat exchange with the two separate fluid flows. During a heating operation, one of the fluid flows, before entering the evaporator, is brought into heat exchange in a first heat exchanger with the refrigeration cycle between the condenser and the regulating valve.

Refrigerator unit, particularly dual temperature refrigerator

Abstract: In a dual temperature refrigerator with a single compressor from which refrigerant flows through a condenser and a capillary tube into a first evaporator, and from the first evaporator through a connecting line into a second evaporator, a refrigerant collector being connected to the condenser at the beginning of the capillary tube, the collector having a volumetric capacity equal to that of the second evaporator and being provided with a heater, a control element in the chamber of the second evaporator intermittently activating the compressor and heater, a suction line from the second evaporator to the compressor, and at least part of the capillary tube in heat-exchange contact with the connecting line. Preferably part of the capillary tube is disposed within the connecting line. Desirably the capillary tube and connecting line are disposed in the insulation of the refrigerator. The invention avoids unwanted drastic temperature drops in the chamber of the second evaporator due to overflowing excess liquid and wet vapor from the first evaporator.

Heat pump and refrigeration system - uses additional sources which include sub-soil water and deep water source

Abstract: A central heating system uses a heat pump and a refrigeration circuit with a compressor, evaporator and condenser for circulating a refrigerating medium combined with an accumulating and generating system which uses a combination of air temperature, water flow, the temperature of the ground underneath and around the site, the water contained within this region, and water pumped up from a much greater depth, and their temperature. These can be used in a closed or part closed hydraulic circuit which can be connected to the heat pump by an exchanger located at the outlet of the evaporator. The temperature and flow of water to this exchanger can be controlled in accordance with its temperature. The speed of rotation of the compressor can be controlled in accordance with the state of the refrigerating fluid at the outlet of the condenser.

Heat pump with refrigerant working fluid - has solenoid valve in high pressure side closed at shut down

Abstract: The heat pump has an evaporator (11) with a heat source (15), a condenser (12) with a heat load (17), a compressor (13) and a thermostatically controlled expansion valve (14). There is a solenoid valve (18) on the high pressure side between the condenser (12) and the expansion valve (14). When the controls (19, 20) stop the compressor, the solenoid valve (18) shuts before the compressor stops and the compressor empties the low pressure side of refrigerant before it stops. This ensures that while the compressor is stopped there is no refrigerant on the low pressure isde which can be absorbed by the lubricating oil so that the oil does not have to be heated to expell refrigerant before the compressor is restarted.

Electro magnetically driven pump with internal expansion valve - has internal return flow system and pressure setting piston

Abstract: An electromagnetically driven pump with spring loaded piston has the expansion valve in the interior of the pump housing (51) attached to a return flow pipeline, counting of channel (29), bore hole (32) pressure equalisation chamber (38) and return channel (30), leading from the high pressure side of the pump to the suction side which also serves as a pressure reservoir A pressure setting piston (35) is provided as a shutting device for the expansion valve This piston (35) can slide within a valve cylinder (37), the bore of which forms the return flow channel (30), such that during conditions of increased pressure the motion of the piston (35) opens a flow exit (36) in the valve cylinder (37) which is connected to the suction side of the pump