Abstract: A refrigeration system includes a compressor, a gas cooler, an expansion device, and an evaporator. Refrigerant is circulated though the closed circuit system. Preferably, carbon dioxide is used as the refrigerant. As carbon dioxide has a low critical point, systems utilizing carbon dioxide as a refrigerant usually require the refrigeration system to run transcritical. When the system is operating inefficiently, the system is modified so the system operates efficiently. First, a parameter of the system is monitored by a sensor and the then compared to a stored value to determine if the system is operating inefficiently. If the system is operating inefficiently, the system is modified to an efficient system.

Abstract: The present invention relates to an air conditioning system provided with an outdoor unit having a compressor and an outdoor heat exchanger, an indoor unit having an indoor heat exchanger, and a gaseous refrigerant pipe connecting the indoor heat exchanger to the compressor. The present invention serves to make it possible to run such an air conditioning system in cooling mode continuously even when the outside air temperature is low by preventing the indoor heat exchanger from freezing. The air conditioning system is provided with one air-cooled outdoor unit and a plurality of indoor units connected in parallel to the outdoor unit. The indoor heat exchangers and the compressor are connected together by the gaseous refrigerant pipe. A pressure adjusting device is installed in the gaseous refrigerant pipe.

Abstract: An air conditioning unit including an expansion device (4) of the refrigerating fluid loop controlled to set the internal heat exchanger efficiency &eegr;, represented by the equation: &eegr;=TccTsc/TsrTsct, wherein: TccTsc and Tsr are respectively temperatures at the compressor input (1), and at the evaporator output (5) and at the fluid cooler output (2), at a reference value such that the fluid leaves the evaporator in a completely gaseous state and without overheating.

Abstract: The present invention relates to an air conditioning system provided with an outdoor unit having a compressor and an outdoor heat exchanger, an indoor unit having an indoor heat exchanger, and a gaseous refrigerant pipe connecting the indoor heat exchanger to the compressor. The present invention serves to make it possible to run such an air conditioning system in cooling mode continuously even when the outside air temperature is low by preventing the indoor heat exchanger from freezing. The air conditioning system (1) is provided with one air-cooled outdoor unit (2) and a plurality of indoor units (3, 4, 5) connected in parallel to the outdoor unit (2). The indoor heat exchangers (23, 24, 25) and the compressor (11) are connected together by the gaseous refrigerant pipe (17). A pressure adjusting device (6) is installed in the gaseous refrigerant pipe (17).

Abstract: Disclosed are a defrosting apparatus of an air conditioner and a method thereof. The defrosting apparatus includes a temperature sensor for sensing a pipe temperature of an outdoor heat exchanger and an outdoor temperature; a comparator for comparing the sensed pipe temperature of the outdoor heat exchanger and the sensed outdoor temperature, and generating and outputting a comparison signal; and a valve controller for increasing an opening value of an LEV (Linear Expansion Valve) at a defrosting operation and decreasing the opening value of the LEV at a defrosting operation termination. The apparatus and the method can increase efficiency of the defrosting operation and reduce a period of time required for performing the defrosting operation by determining the defrosting operation based on a difference between a pipe temperature of an outdoor heat exchanger and an outdoor temperature and increasing an opening value of an LEV at the defrosting operation.

Abstract: A controller for an expansion valve of a refrigeration system for cooling a medium is configured to include, in the generation of a control signal, a measure of the evaporation temperature (T0) of the refrigerant in an evaporator and a measure of a property of the cooled medium, preferably without influence from a measure of the superheat temperature (SH) of the refrigerant. The controller comprises a PI-element for integrating and for producing a control signal for the expansion valve for controlling the flow of refrigerant into the evaporator, the PI-element being arranged in an inner control loop, a reference for which is produced by an outer control loop. The controller allows for fast response to disturbances and/or fast response of the medium temperature when the operating conditions of the refrigeration system are changed and/or fast response during start-up of the refrigeration system and maintains stable operation conditions with low, but positive superheating and a stable evaporation pressure.

Abstract: An air conditioner has a refrigerant circuit, a control valve, a detector, a calculator, a suction pressure sensor and a compressor controller. The refrigerant circuit includes a variable displacement compressor. First and second pressure monitoring points are located in the refrigerant circuit. The control valve includes an actuator and a pressure sensing mechanism that has a pressure sensing member and a valve body. The detector detects cooling load information in the refrigerant circuit. The calculator calculates a target pressure in a relatively low pressure region in the refrigerant circuit in response to the detected cooling load information. The suction pressure sensor detects actual pressure in the reiatively low pressure region in the refrigerant circuit. The compressor controller controls the actuator to eliminate a differential between the calculated target pressure and the detected actual pressure.

Abstract: A method and apparatus for refrigeration system control includes an evaporator pressure regulator and sensor in communication with one of a plurality of refrigeration circuits. The sensor is operable to measure a parameter of the refrigeration circuit. A controller is operable to adaptively control a suction pressure of the compressor rack based upon the measured parameter, whereby the controller controls a circuit temperature for one of the plurality of circuits. Further, the controller is operable to control the electronic evaporator pressure regulator to control the temperature in the one of a plurality of refrigeration circuits by determining a change in the parameter and updating a set point based upon the change of parameter.

Abstract: An expansion valve has a tube body, in which a first filtering net, drying agents, a bullet-shaped filtering net, and a, reducing body are integrated. The tube body has front and rear ends respectively joined to an inlet tube, and an outlet tube. The first filtering net is disposed at the front end of the tube body. The drying agents are contained in a front portion of the tube body. The bullet-shaped filtering net is disposed in the drying agents. The reducing body is disposed in a rear portion of the tube body, and has an expansion hole, and front and fear reducing openings in communication with the expansion hole; the front and rear reducing openings are respectively joined to an enlarged end of the bullet-shaped filtering net, and the outlet tube.

Abstract: The invention concerns an air conditioning unit wherein the expansion device (4) of the refrigerating fluid loop is controlled to set the internal heat exchanger efficiency &eegr;, represented by the equation: &eegr;=TESTSE/TSTTSE, wherein: TESTSE and TST are respectively temperatures at the compressor input (1), and at the evaporator output (5) and at the fluid cooler output (2), at a reference value such that the fluid leaves the evaporator in a completely gaseous state and without overheating.

Abstract: The performance of mobile air conditioning systems is improved with the use of a pressure sensing valve to control refrigerant flow in the system. The pressure sensing valve is connected between the condenser and the evaporator. The control valve senses the refrigerant pressure adjacent the evaporator, ie. the input, or output, or the combination of both, to control the refrigerant flow through the evaporator in a manner to improve the performance of the system. The reference pressure for the valve can be the atmosphere or a fixed or variable source. Various other operating variables can be sensed to control the variable source in a manner to interact with the sensed pressure to provide added control of system performance.

Abstract: In a heat-pump water heater with a super-critical refrigerant cycle, a valve open degree of a decompression valve is controlled to control a pressure of high-pressure side refrigerant so that a temperature difference between refrigerant flowing out from the water-refrigerant heat exchanger and water flowing into a water-refrigerant heat exchanger is set in a predetermined temperature range. Thus, the pressure of high-pressure side refrigerant in the super-critical refrigerant cycle can be controlled, thereby suitably adjusting heat-exchange performance of an internal heat exchanger, and restricting the temperature of refrigerant discharged from the refrigerant compressor from being uselessly increased.

Abstract: To provide an expansion valve which permits both the assembling cost and the cost of parts to be effectively reduced by a large margin and thus is highly economical. A high-pressure refrigerant pipe, a valve casing and a low-pressure refrigerant pipe are previously formed integrally with an evaporator. At the time of assembling, an expansion valve unit having a minimum function to serve as an expansion valve is inserted into the valve casing and fixed thereto by a clip, and a distal end portion of a temperature sensing cylinder is fixed to an outlet pipe of the evaporator, thereby constructing an expansion valve. No special joints are required to connect the expansion valve unit to the high-pressure and low-pressure refrigerant pipes, and therefore, the cost of parts can be cut down.

Abstract: Reference 100′ refers to a heat-sensing driven member constituting a thermal expansion valve formed by a stainless steel material and the like and having in the inside thereof an adsorbent 40, with a collar 100′a formed to the outside of the opening 100′b of the heat-sensing driven material 100′. A protrusion 100′c and a groove 100′d is formed to said collar 100′a in the downward direction of the drawing. Said protrusion 100′c and said groove 100′d are formed to the whole perimeter of said collar 100′a. Moreover, a diaphragm 82a formed for example of stainless steel material is inserted to said heat-sensing driven member 100′ through an opening 82b formed to the center area thereof until it contacts said protrusion 100′c, and said diaphragm 82a is fixed to said heat-sensing driven member 100′. As a result, the diaphragm 82a is welded by said protrusion 100′c between said collar 100′a and said support member 82′a.

Abstract: A heat pump cycle system which can switches cooling operation and heating operation for a compartment includes a first inside heat exchanger and a second inside heat exchanger disposed in an air conditioning case. The first inside heat exchanger is disposed in the air conditioning case at a downstream air side of the second inside heat exchanger, while being arranged in line in a flow direction of refrigerant. The first inside heat exchanger is upstream from the second inside heat exchanger in the flow direction of refrigerant during the heating operation. In the heat pump cycle system, an expansion valve is controlled so that coefficient of performance in each operation becomes approximately maximum. Thus, during the heating operation of the heat pump cycle system, a lower limit temperature of air blown from the inside heat exchangers can be increased so that temperature of air blown into the compartment is increased, while the coefficient of performance is improved.

Abstract: A control device is provided for a refrigerant circuit of an air conditioner, divided by a compressor and a vent element into a high-pressure side and a low-pressure side. The control device includes a high-pressure-side control part and a low-pressure-side control part for controlling one or more controllable high-pressure-side or low-pressure-side system components. The two control parts are coupled with one another, with at least one influential parameter of one control part forming a coupling parameter that is coupled into the other control part as an influential parameter that is effective there as well. The control device is useful for carbon dioxide air conditioners of motor vehicles.

Abstract: The performance of mobile air conditioning systems is improved with the use of a pressure sensing valve to control refrigerant flow in the system. The pressure sensing valve is connected between the condenser and the evaporator. The control valve senses the refrigerant pressure adjacent the evaporator, i.e. the input, or output, or the combination of both, to control the refrigerant flow through the evaporator in a manner to improve the performance of the system. The reference pressure for the valve can be the atmosphere or a fixed or variable source. Various other operating variables can be sensed to control the variable source in a manner to interact with the sensed pressure to provide added control of system performance.

Abstract: An arrangement is provided for insuring that excessive demand is not placed on a refrigeration unit that supplies pressurized subcooled refrigerant to different channels having independent needs for use of refrigeration capacity. A separate reference channel receives a portion of the refrigerant and expands the refrigerant fully to a gas phase to establish a minimum level reference temperature. In the operative channels the refrigerant flows into individual evaporators/heat exchangers at rates set by external command signals, the refrigerant being in heat exchange relation with thermal transfer fluid in the evaporator/heat exchanger. Evaporation of refrigerant in each channel thus brings the thermal transfer fluid for that channel to the target temperature. By comparing the post evaporation temperature in each channel to the reference temperature and reducing the refrigerant flow rate whenever the difference is below a threshold, individual channels are not overtaxed and the system remains stable.

Abstract: In a process for regulating a refrigeration system (1) using an expansion valve (4), one side of the regulating member is pressed by the pressure of refrigerant at the evaporator side and the other side of the regulating member is pressed by the vapor pressure of a sensor system (22) whose sensor temperature is determined by the refrigerant saturation temperature and by the heat supplied by a heating element (27). heat supply is regulated depending on a measurement value (overheating or liquid level). Also disclosed is a refrigeration system (1) regulated in this manner and an expansion valve (4) as essential component of such a system. An improved, exonomic and universally applicable regulation can thus be obtained.

Abstract: Temperature comparison circuits which utilize two thermistors which are initially set up in a balanced bridge using NPN transistors and resistors. As temperature differences between the thermistors cause the bridge to become unbalanced, there is a current flow in which the voltage varies in magnitude and direction. The circuits are attached to electrical equipment which is sensitive to changes in magnitude and direction of voltage. The circuits find uses in controlling refrigeration systems, controlling heating and cooling systems, and performing diagnostic tests on mammals or devices which contain temperature differences between two separate points. The circuits may be used in cooperation with an expansion valve which is located in the tubing of a refrigeration system. The tubing is non-magnetic. There is a fixed magnetizable plate having a central orifice.

Abstract: The present invention consists of a refrigeration unit with an adjusting valve that functions to control the flow of refrigerant and which is installed between the condenser and the evaporator. The adjusting valve is modulated by a controller that adjusts the refrigerant flow from the condenser to the evaporator, depending upon the outflow refrigerant vapor pressure coming from the compressor, condenser, or evaporator. Thus, substantial energy losses are avoided.

Abstract: A method of controlling an expansion valve including the steps of: measuring a primary system condition; determining an error in the primary system condition; measuring a secondary system condition; determining an error in the secondary system condition; and modulating the expansion valve based upon the larger of the first or second error.

Abstract: An air conditioner capable of enhancing responsivity of a blowout temperature of conditioned air while preventing occurrence of an overshoot or undershoot condition of the blowout temperature when a user gives an instruction to change the blowout temperature in a dehumidifying operation mode. In a control state, if a set temperature level is adjusted to increase a blowout temperature of conditioned air by increasing the target condenser outlet temperature, the rotating speed of the refrigerant compressor is increased, while the restriction opening of the heating expansion valve is maintained. Thus, the condenser outlet temperature is regulated to the target temperature with minimal undershoot or overshoot of the target temperature.

Abstract: A process for controlling a refrigeration system, as well as the refrigeration system and a new expansion valve for the refrigeration system. An electronic regulator is used to operate a sensor system having a device for applying heat power to the sensor system in direct dependence on sensed superheat of the refrigerant leaving the evaporator. By locating the sensing system in communication with liquid refrigerant upstream of the evaporator, heat transfer to the liquid refrigerant is utilized for operation of the sensor system rather than heat transfer to the superheat, resulting in a far more stable and efficient refrigeration control.

Abstract: A control-information detecting apparatus for a refrigeration air-conditioner using a non-azeotrope refrigerant is equipped with a temperature detector and a pressure detector at the refrigerating cycle of the air-conditioner, which cycle is formed by connecting a compressor, a condenser, a decompressing device, and an evaporator, to detect the temperature and the pressure of the refrigerant circulating the cycle for obtaining the circulation composition of the refrigerant with the composition computing unit thereof. The usual optimum operation of the cycle is thereby enabled even if the circulation composition of the refrigerant has changed.

Abstract: A heat pump apparatus which includes: an accumulator and a sub-accumulator for additionally accommodating the refrigerant arranged between the accumulator and the compressor, in which at least the accumulator or the sub-accumulator is provided with a flow control valve for controlling the refrigerant flow upstream of the accumulator or the sub-accumulator in association with the liquid refrigerant level detected by the level sensor; a bypass line with a bypass valve for bypassing the expansion valve, for controlling the opening of the bypass; and, preferably, a level sensor for sensing the liquid refrigerant level therein; thereby inhibiting the occurrence of foaming of the refrigerant and preventing the refrigerant from entering the compressor, especially at the start-up of the compressor.

Abstract: Compressor discharge temperature, ambient outdoor air temperature and thermal load are used as control parameters for controlling the expansion valve setting and indoor fan speed. Diagnostics monitor a feedback signal from the fan motor to detect fan over-speed and increased speed due to decreased air flow caused by a dirty indoor air filter. Discharge pressure of the compressor is monitored to detect a blocked outdoor fan. The difference between actual and optimum compressor discharge temperatures and suction pressure of the compressor are monitored to detect a stuck-closed expansion valve or low refrigerant charge. Compressor "short-cycling" is limited to prevent reduced reliability of the compressor. The difference between compressor discharge temperature and outdoor coil temperature is measured before and after startup to detect compressor failure.

Abstract: Cooling apparatus is disclosed which comprises a reservoir for compressed, preferably liquified, gas, the reservoir being connected to tubing 130 arranged to be disposed in an article of clothing adjacent to the skin of a user. A solenoid 230 is provided for opening a valve 240 between the reservoir 100 and the tubing 130 to allow pressurized gas to evaporate and escape from the reservoir along tube 130. As the gas evaporates it cools due to latent heat of evaporation thus providing a cooling effect to the user due to heat transfer through the walls of tubing. A control device 200 is provided for regulating the output of cooling gas in dependence on temperature.

Abstract: Pulse width modulation is used to control the flow rate through a solenoid expansion valve in a refrigeration system. A first temperature sensor is located near the evaporator inlet, and a second temperature sensor is disposed in a compartment to be cooled. A controller is included for controlling the duty cycle of the pulse width modulated solenoid valve. The controller receives inputs from the two temperature sensors and controls the valve duty cycle based on the difference of the two temperatures. The second temperature sensor is preferably located on the back wall of the compartment and can be adjacent to the compartment air inlet, adjacent to the compartment air outlet, or between the air inlet and air outlet.

Abstract: A refrigeration system of the type having an economizer cycle is provided with a null cycle, in addition to heating and cooling cycles, without shutting a compressor prime mover down, to preserve air flow in a conditioned space. First, second and third controllable valves respectively: (1) select main and auxiliary condensers, (2) open and close a liquid line, and (3) open and close a line which provides a warm liquid to an economizer heat exchanger. The valves are controlled in at least one predetermined open/close pattern during a null cycle, and preferably in a plurality of selectable predetermined open/close patterns, to provide a null cycle at any instant which substantially matches the net heat gain or loss taking place in the conditioned space. Thus, the temperature of the served space will be more apt to remain in a null temperature range close to set point, providing smoother and more accurate control over the temperature of the conditioned space for longer shelf life of perishables stored therein.

Abstract: Liquid pressure amplification with superheat suppression is used in an air-conditioning or refrigeration system which includes a compressor, a condenser, an expansion valve, and an evaporator, interconnected by conduits in a closed refrigerant loop. A first conduit coupling an outlet of the compressor to an inlet to the condenser. A centrifugal pump is coupled to the condenser (or receiver) outlet for boosting the pressure of the condensed liquid refrigerant by a substantially constant increment. A second conduit transmits a first portion of the condensed liquid refrigerant from outlet of the pump through the expansion valve into the evaporator to effect cooling. A third conduit transmits a second portion of the condensed liquid refrigerant from the pump outlet into the condenser inlet, which cools the superheated vapor refrigerant entering the condenser, reducing head pressure.

Abstract: A thermodynamic system, such as a vapor compression refrigeration system, in which a binary expansion valve allows pulsed high velocity flow to an evaporator through an isentropic flow nozzle wherein the valve is controlled in response to evaporator pressure.

Abstract: Refrigerant flowing through each air conditioning unit of a multiple air conditioning system is respectively detected by a refrigerant flow sensor provided in each air conditioning unit and the degree of opening of a refrigerant flow control valve arranged in each air conditioning unit is controlled in response to the detection result of the corresponding refrigerant flow sensor to supply an appropriate amount of refrigerant to each air conditioning unit. The capacity of the compressor of a refrigerant supply unit of the multiple air conditioning system is controlled based on the detection result of each refrigerant flow sensor and the actual opening degree of each refrigerant flow control valve.

Abstract: A Joule-Thomson cryogenic refrigeration system capable of achieving high temperature stabilities in the presence of varying temperature, atmospheric pressure, and heat load is provided. The Joule-Thomson cryogenic refrigeration system includes a demand-flow Joule-Thomson expansion valve disposed in a cryostat of the refrigeration system. The expansion valve has an adjustable orifice that controls the flow of compressed gas therethrough and induces cooling and partial liquefaction of the gas. A recuperative heat exchanger is disposed in the cryostat and coupled to the expansion valve. A thermostatically self-regulating mechanism is disposed in the cryostat and coupled to the J-T expansion valve. The thermostatically self-regulating mechanism automatically adjusts the cross-sectional area of the adjustable valve orifice in response to environmental temperature changes and changes in power dissipated at a cold head.

Abstract: A refrigeration cycle apparatus includes a compressor, condenser, pressure-reducing device, evaporator, and gas-liquid separator between the pressure-reducing device and the evaporator. The gas-liquid separator separates a coolant from the pressure-reducing device into a liquid coolant and a gas coolant. A conduit between the gas-liquid separator and the evaporator supplies the separated liquid and gas coolant into the evaporator at a predetermined rate for controlling the quality of the coolant downstream of the gas-liquid separator, thereby attaining a super-cool condition of the coolant at the outlet portion of the condenser.

Abstract: A transport refrigeration system, and method of operating same, in which a maximum operating pressure expansion valve and a secondary condenser are used to enhance hot gas heating cycles initiated to hold a predetermined temperature set point, and hot gas defrost cycles. The secondary condenser is disposed in an evaporator section of the refrigeration system, with hot discharge gas from a compressor being directed to the secondary condenser during heating and defrost cycles. A sufficient supply of refrigerant for heating and defrost cycles is ensured by injecting refrigerant from a receiver and condenser into an active heat cycle refrigerant circuit, when the active refrigerant is insufficient to build the pressure on the low pressure side of the refrigeration system to a value sufficient to close the maximum operating pressure expansion valve and the compressor suction pressure is less than the receiver/condenser pressure.

Abstract: Liquid carbon dioxide is injected through one end into the upper compartment (14) of the tunnel. The gaseous CO.sub.2 is circulated in the lower compartment (13) partly in a countercurrent manner and partly in a cocurrent manner relative to the objects (22) to be cooled, by a central fan (9). Application in the temporary hardening of products of rubber and plastics material and in the precise cooling of food products.

Abstract: A vapor-compression refrigeration system has a continuously operating compressor, with loading on the compressor varied in accordance with conditions and cooling needs. The system avoids any on/off cycling of the compressor or valves in the system, but instead keeps cooling and bypass valves open to varying and proportional degrees depending upon requirements. The system includes several bypass loops, for bypassing coolant fluid to a proportional degree when a desired temperature is approached in a body to be cooled; and when temperature of return gas to the compressor approaches a limit temperature beyond which the compressor should not operate. In the latter case, cool liquid is injected, while expanding and vaporizing, into the hot gas for cooling, to protect the compressor.

Abstract: A method and control system are disclosed for operating a refrigeration system to protect the refrigeration system compressor from flooding at startup of the refrigeration system. When the refrigeration system is to be shut down, refrigerant flow from a condenser to an evaporator of the refrigeration system is effectively closed off and the refrigeration system compressor is run for a first preselected time period sufficient to reduce the refrigerant pressure in the evaporator to a first desired, relatively low level. Then, prior to restarting the refrigeration system, the compressor is again run with the refrigerant flow from the condenser to the evaporator closed off to pump refrigerant out of the evaporator to reduce the refrigerant pressure in the evaporator to a second desired, relatively low level.This dual pump down cycle ensures that no liquid refrigerant from the evaporator will enter the compressor when the refrigeration system is restarted.

Abstract: An arrangement and method of controlling optimum chilled water temperature supplied to a process by a pump, the water being chilled by coolant in a coolant cycle having a compressor and a load valve, comprises first and second sensors for sensing a supply and a return temperature to and from the process. A value is obtained for the amount of work done by the pump and the compressor with that value as well as the supply and return temperature values being supplied to a supervisory control. The supervisory control operates to generate a reference temperature which is a function of the supply temperature but which is either above or below the supply temperature depending on a ratio between the difference in work and a change in the difference between the supply and return temperatures. When the ratio is about zero this indicates the difference between supply and return temperature is at an optimum and the reference temperature is the same as the supply temperature.

Abstract: Apparatus and method for operating a series compression refrigeration system are disclosed. A by-pass for circuiting refrigerant around one compressor when the compressor is not operating is provided. Additionally, a quench conduit conducts liquid refrigerant from a common line to provide a liquid refrigerant quench of the gaseous refrigerant between compressors. A control device is provided for regulating the flow of liquid refrigerant through the quench conduit.

Abstract: Apparatus and method for operating a series compression refrigeration system are disclosed. A by-pass for circuiting refrigerant around one compressor when the compressor is not operating is provided. Additionally, a quench conduit conducts liquid refrigerant from a common line to provide a liquid refrigerant quench of the gaseous refrigerant between compressors. A control device is provided for regulating the flow of liquid refrigerant through the quench conduit.

Abstract: A method and apparatus for controlling the operation of a refrigeration system, for example, is provided which includes a first sensor for monitoring the sump temperature of a compressor used in conjunction with the refrigeration system, and a second sensor which monitors compressor ambient air temperature. The refrigeration system includes an electrically operable expansion valve and the sensors are employed in a control device operatively connected to the electrically controlled expansion valve to control the operating position of that valve. Refrigeration system operation can be controlled precisely, thereby maximizing the efficiency of the system, by monitoring the sump temperature and ambient temperature of the compressor.

Abstract: A thermostatic expansion device for use in refrigeration systems includes a valve member adapted to control the flow of liquid refrigerant from a condenser to an evaporator of the refrigeration system. A pressure-responsive device is operatively connected to the valve member for responding to a differential pressure in the refrigeration system so as to open and close the valve member. A temperature-responsive device is operatively connected to the pressure-responsive device for responding to a temperature of the refrigerant at the outlet of the evaporator. A lead-lag compensation structure is connected to the pressure-responsive device for permitting a rapid movement of the valve member upon the occurrence of a sudden change either in the temperature of the refrigerant at the outlet of the evaporator or in the pressure at the inlet of the evaporator thereby maintaining a constant superheat at the outlet of the evaporator so as to effect stability of the refrigeration system.

Abstract: A heat exchange interface apparatus for installation between a conventional working fluid unit such as an air conditioner or heat pump and a distribution system such as finned heat exchange tubing installed around the perimeter of a domestic or commercial building. The interface apparatus includes a variable, self adjusting valve which controls and regulates the amount of cooling fluid delivered to the heat exchange tubing in accordance with the temperature of the working fluid at the outlet end of the heat exchange tubing.

Abstract: A refrigerant flow control assembly for metering the flow of refrigerant, under low load and normal operating conditions, from the high pressure side to the low pressure side of refrigeration machine. The assembly includes a valve plate defining a circular port for the flow of refrigerant therethrough. A valve plug is provided having a conical surface at one end for communication with the circular port, and a stem at the other end. A valve plug support is operatively connected to the valve plate for mounting thereon the valve plug for slidable movement between a closed position and an open position along a line coincident with the axis of the valve plug, which line is perpendicular to and intersects the plane of the circular port at its center.

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.

Abstract: A portable apparatus for sequentially cooling a pluraity of containers of beverages and the like includes a portable housing containing the following devices. An evaporator circulates a refrigerant therethrough and defines a receptacle for receiving a container to be cooled in close heat-conducting relation thereto. A supply tank initially contains pressurized refrigerant sufficient for cooling a plurality of containers. A conduit transmits the pressurized refrigerant from the supply tank to the evaporator. A valve forms a part of the conduit and includes devices for actuating the valve to allow the flow of pressurized refrigerant from the supply tank and devices responsive to the flow of a predetermined quantity of refrigerant from the supply tank sufficient for cooling a single container for deactuating the valve device to stop the flow of refrigerant from the supply tank and provide the predetermined quantity of refrigerant to the evaporator for cooling the container received in the receptacle.

Abstract: In a cryogenic cooler, wherein a fluid under pressure is transmitted through an expansion orifice in a nozzle into an expansion chamber at a rate which is controlled by the movement of a needle valve in the expansion chamber, an expander member extends from the nozzle and carries the needle valve. The expander member expands and contracts in response to the temperature in the expansion chamber at a different rate than the needle valve to automatically regulate the flow of fluid into the expansion chamber.

Abstract: A piloted refrigerant valve for an air conditioning system to control refrigerant pressure within an evaporator to prevent frost accumulation on its exterior surfaces. The valve includes a disc-shaped hollow thermal sensor filled with water which solidifies and expands upon sensing the freezing temperature to cause a pilot valve to block a bleed port and thereby increase the fluid pressure above a reciprocally mounted piston valve. The pressure force produced on the piston valve moves it to a closed position to block refrigerant flow and resultantly to increase refrigerant pressure and temperature in the evaporator. After an initial start-up period of operation, the sensor maintains a position which locates the reciprocal piston valve so as to produce a substantially constant non-freezing temperature of refrigerant in the evaporator.