Abstract: An improved method and apparatus for limiting the pressure in the high pressure side of a heat pump system to a safe value, without causing the defrost control circuitry thereof to initiate unnecessary defrost cycles. When the heat pump system is operating in its heating mode, pressure limiting circuitry limits the pressure in the high side thereof to a safe value by turning the outdoor fan off, and holding it off, when the vapor pressure in the vapor containing parts of the system is equal to or greater than a preset threshold pressure. When ambient conditions are such that frost is able to form on the outdoor coil, the activity of the pressure limiting circuitry is used to reset the defrost delay time or otherwise inhibit the operation of the defrost control circuitry.

Abstract: An evaporative condensing apparatus used in an air conditioner to reduce the power consumption of the air conditioner and improves its EER value. The evaporative condensing apparatus is based on the rule that the condensing temperature is directly proportional to the condensing pressure during the exchange of a cooling agent between liquid state and gas state.

Abstract: In a heat pump system designed for use with a relatively low pressure refrigerant, provision is made, by use of a vapor pressure control system, to use a higher pressure refrigerant without replacement of the indoor coil and the line set. The vapor pressure is sensed during periods of heat pump operation, and when the pressure reaches a predetermined maximum threshold level, the outdoor fan speed is reduced to thereby cause the vapor pressure to be reduced. When the vapor pressure is reduced to a predetermined minimum threshold level, then the fan speed is resumed so as thereby allow the vapor pressure to again be increased.

Abstract: A second condenser includes a condensation promoting portion that promotes a condensation action on a refrigerant by reduction of the sectional area of a refrigerant path. The condensation promoting portion includes a step-forming wall between the sectional area reduced portion and a refrigerant path portion in the upstream thereof A vortex/turbulent flow generator is provided as necessary in the upstream and downstream of the sectional area reduced portion of the refrigerant path. The air conditioner includes a first condenser and a second condenser that are coupled in a crossflow manner so that an object for heat exchange, that is, a coolant passes first through the second condenser including the condensation promoting portion and then through the first condenser.

Abstract: A method for preventing an evaporator of an air conditioner from freezing comprises the steps of (1) detecting an outdoor temperature, (2) determining whether or not the outdoor temperature is 20.degree. C., (3) determining whether or not the outdoor temperature is in a first temperature range, (4) determining whether or not the outdoor temperature is in a second temperature range, (5) varying an R.P.M. of the motor assembly based on the outdoor temperature detected in steps (3) and (4), (6) detecting a surface temperature of a condenser and determining whether or not the surface temperature of the condenser is in a third temperature range, (7) repeating steps (1) through (6) if the surface temperature of the condenser is higher than the third temperature range, and (8) rotating the motor assembly at a low speed if the surface temperature of the condensor is lower than the third temperature range.

Abstract: A refrigerating system, using CO.sub.2 as a refrigerant, for an air conditioner for an automobile. A pressure at the outlet of the heat emitter 2 is controlled to a target value in accordance with the temperature of the refrigerant at the outlet of the heat emitter for obtaining an operation of the refrigerating system along the optimum control line .eta..sub.max. A pressure reducer 4 and a cooler 5 are provided on a branched passageway 28 branched from a refrigerant recirculating passageway 27 for injection. The cooler 5 is for obtaining a heat exchange between a flow of the refrigerant on the branched passageway 28 after being cooled by the pressure reducer and a flow of the refrigerant on the main passageway 27, thereby cooling the refrigerant directed to the evaporator. In a second aspect of the invention, a means is provided for increasing a target value of the pressure at the pressure reducer when a thermal load of the refrigerating system is high.

Abstract: A heat pump system usable as an air-conditioning apparatus, a refrigerant apparatus, or a temperature-conditioning apparatus, having a heat capacity detection mechanism for detecting a signal indicative of a ratio of or a difference between the total heat-emitting capacity of the condenser and the total heat-absorbing capacity of the evaporator, and an energy-supplying mechanism for exerting energy onto the refrigerant, thereby compensating for insufficient total hear-absorbing capacity, especially in the cooling mode when condensation capacity increases due to, for example, a cold or wind environment.

Abstract: An icemaker having a means for bypassing a head pressure control valve thereof depending upon the ambient air temperature surrounding a remotely located condenser of the icemaker. The method and apparatus involve a first bypass conduit which is coupled to an outlet of the condenser upstream of the head pressure control valve and a first bypass valve disposed in the first bypass conduit. A second bypass conduit is in communication with an inlet of the condenser and also with the head pressure control valve. A second bypass valve is disposed in the second bypass conduit. A thermostat controls each of the bypass valves such that the first bypass valve is closed and the second bypass valve opened when the sensed ambient air temperature around the condenser is below a predetermined temperature, to thereby permit normal operation of the head pressure control valve.

Abstract: A control apparatus for a gas injection type air conditioning system that prevents lowering of compressor speed and cycle stoppage under conditions where high pressure is liable to occur. During a system heating mode, a pressure change rate ASP of the high pressure of the refrigerating cycle is calculated. When a pressure change rate .increment.SP rises above a predetermined value, a system electric expansion valve aperture is reduced. Accordingly, by calculation of the pressure change rate .increment.SP, it is possible to control the electric expansion valve in the above manner earlier than in prior art control schemes when there is a sudden rise in the high pressure.

Abstract: A compressor discharge pressure control system employed on a container refrigeration unit utilizes a pressure transducer located in the high pressure side of the system and a data processor to control and limit the compressor discharge pressure to a maximum value when the normal condenser pressure controls are inactive. The pressure control system operates the suction modulation valve in a manner that significantly reduces compressor cycling and increases refrigeration system capacity during pull-down periods. The pressure control system also operates during water-cooled operation of a refrigeration system having a water-cooled condenser thereby eliminating the need to provide a water pressure switch in the refrigeration system.

Abstract: A cooling module for an automotive vehicle is disclosed. The module includes a pair of bypass doors for directing a flow of air around either of the condenser or radiator in the module depending upon the demands for engine cooling, air conditioning, and any other cooling requirements. Under suitable conditions, the radiator bypass feature or the condenser bypass feature will open, providing additional cooling for the condenser or radiator respectively, in order to satisfy given cooling requirements more efficiently.

Abstract: A heat pump system usable as an air-conditioning apparatus, a refrigeration apparatus, or a temperature-conditioning apparatus, having stable cooling, heating, or freezing capacity without significant influence from the difference in height between the expansion valve and the compressor, and the length of piping of the refrigerant circulation line, which system comprises a pressure sensing means for measuring the pressure in the refrigerant line immediately upstream of the expansion valve; optionally a pressure sensing means for measuring the pressure in the refrigerant line immediately downstream of the compressor; and an energy-supplying mechanism for exerting energy onto the refrigerant when the measured pressure is lower than a predetermined value, thereby controlling the pressure in the high pressure refrigerant line.

Abstract: A heat exchanger and heat pump circuit having an operating subcircuit and a pump down subcircuit each including a liquid line and a heat transfer tube. The heat transfer tube of the pump down subcircuit surrounds the liquid line of the operating subcircuit. During the heating cycle, the heat pump circuit circulates refrigerant through both subcircuits to abstract heat from the heat source/sink. However, during the cooling cycle, the heat pump circuit circulates refrigerant only through the operating subcircuit. Also during the cooling cycle, the heat pump circuit places the pump down subcircuit at low pressure to thermally insulate the operating subcircuit liquid line.

Abstract: The present invention is a method for operating an air conditioner chiller system under high ambient air conditions. When the temperature of the standard discharge saturation temperature increases above a first predetermined temperature as a result of a rise in ambient air temperature, an expansion valve is throttled to reduce the capacity of the system compressor. The amount of throttling can be made to be dependent on the amount that the discharge temperature exceeds the first predetermined temperature so that compressor capacity is reduced by an amount no more than is necessary to assure that a maximum operating design pressure is not exceeded.

Abstract: An engine-driven heat pump apparatus having a refrigerant circulation line which includes at least one inside heat-exchanger for exchanging heat between the air in a room and the refrigerant, and a pressure-controlling device for substantially maintaining the pressure on the high pressure side of the refrigerant circulation line by, for example, narrowing the opening of the expansion valve(s), decreasing the volume of air passing through the inside heat-exchanger(s), recirculating the air passing through the inside heat-exchanger(s), lowering the heat efficiency of the engine when the required quantity of radiated heat from the inside heat-exchanger(s) in use is increased, e.g., when the number of inside heat-exchanger(s) in use is increased, thereby maintaining or increasing heating power in the heating mode, irrespective of the number of inside heat-exchangers in use.

Abstract: In a heat pump system operating in the heat cycle mode, a sensor is provided for sensing either the pressure or temperature of a refrigerant. A speed controller receives an output of the sensor so that the speed (including cycle rate) of an evaporator fan is controlled, resulting in control of the pressure or temperature of the refrigerant. The temperature or pressure of the refrigerant is controlled for a heat pump system comprising one refrigeration circuit and more than one refrigeration circuit. A separate speed control is provided for a fixed speed motor, a sleeve bearing fan motor, and a variable speed ball bearing fan motor.

Abstract: A method for continuously operating a multi-temp refrigeration system at a high compressor speed is provided. Such refrigeration systems include a compressor for compressing a refrigerant at a high speed and a low speed, a condenser coil for receiving and liquefying gaseous refrigerant, first and second evaporator coils for heating or cooling two different conditioned spaces, a hot gas valve for admitting hot gaseous refrigerant to one of the evaporator coils in order to heat its associated conditioned space, and a condenser inlet valve for rerouting a flow of hot gaseous refrigerant from the condenser coil to the evaporator coils. In the method of the invention, the evaporator hot gas valve is first opened to heat one of the conditioned spaces, and the condenser inlet valve is then closed to direct a flow of hot gaseous refrigerant to the opened hot gas valve.

Abstract: A refrigeration system includes in a closed loop connection a compressor for compressing a refrigerant, a desuperheater for cooling the hot compressor discharge gas via the injection of liquid refrigerant, and a condenser for condensing the compressed, desuperheated refrigerant into a liquid refrigerant. The liquid refrigerant is injected into the compressed refrigerant by utilizing a liquid column for supplying pressure to the liquid refrigerant for injecting liquid refrigerant into the compressed refrigerant without using a mechanical pump. Another method of injecting the liquid refrigerant into the compressed refrigerant is to use a venturi pump at the injection point to supply the liquid refrigerant for injection into the compressed refrigerant. The desuperheater causes the temperature of the hot refrigerant vapor leaving the compressor to be reduced from a superheated condition to temperature closer to its condensing temperature prior to its entry to the condenser.

Abstract: Apparatus for providing integrated control of a space cooling system is disclosed. The apparatus receives inputs from a plurality of temperature sensors, including a temperature sensor for measuring evaporator superheat, space temperature and compressor discharge temperature. The control apparatus incrementally adjusts the position of the cooling system expansion valve to regulate evaporator superheat and compressor discharge temperature and cycles the outdoor condenser fan on and off to raise condenser pressure in response to a low condenser pressure condition. In one embodiment, the cooling system includes a plurality of evaporators and a corresponding plurality of controllers electrically interconnected in a series loop for controlling the expansion valves and defrost heaters associated with the respective evaporators.

Abstract: This invention is a low pressure refrigeration or air-conditioning system comprising a compressor, a condenser and an evaporator interconnected in series in a closed loop for circulating refrigerant therethrough, and an improved subcircuit including a subcooler and centrifugal pump connected in series to recycle a portion of the liquid refrigerant from the condenser outlet back to the condenser inlet to desuperheat compressed refrigerant vapors. The subcooler receives a portion of the condensed liquid refrigerant from the outlet of the condenser at condenser outlet temperature and lowers that temperature by an increment of temperature, typically about 2.degree.-3.degree. F., to a temperature sufficiently lower than the condenser outlet temperature to prevent flashing of the refrigerant in the pump intake.

Abstract: A compression-type refrigeration system is disclosed, in which "flash gas" formation is eliminated without artificially maintaining condenser temperature and pressure levels. Condenser temperatures and pressures are allowed to fluctuate with ambient operating conditions, resulting in reduced compressor load and increased refrigeration capacity. After condensation, liquified refrigerant in the conduit between the receiver and the expansion valve is pressurized without adding heat, by means of a combination of (a) a positive-displacement pump, in parallel with the conduit, (b) a bypass conduit pressure regulating controller, and (c) a check valve in the conduit, to a pressure sufficient to suppress flash gas in the conduit. A variable speed liquid injection pump is provided to inject liquid refrigerant from downstream of the positive-displacement pump to upstream of the condenser, at a controlled rate sufficient to desuperheat the refrigerant upstream of the condenser.

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 compression-type refrigeration system is disclosed, in which "flash gas" formation is eliminated without artificially maintaining condenser temperature and pressure levels. Condenser temperatures and pressures are allowed to fluctuate with ambient operating conditions, resulting in reduced compressor load and increased refrigeration capacity. After condensation, liquified refrigerant in the conduit between the receiver and the expansion valve is pressurized without adding heat, by means of a combination of (a) a positive-displacement pump, in parallel with the conduit, (b) a bypass conduit pressure regulating controller, and (c) a check valve in the conduit, to a pressure sufficient to suppress flash gas in the conduit. A variable speed liquid injection pump is provided to inject liquid refrigerant from downstream of the positive-displacement pump to upstream of the condenser, at a controlled rate sufficient to desuperheat the refrigerant upstream of the condenser.

Abstract: A system for diverting refrigerant into an auxiliary receiving vessel to reduce refrigerator system pressure during an incipient over-pressure condition to prevent activation of safety pressure relief valves and release of refrigerant into the atmosphere.

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 mass flow control apparatus and method for use in combination with a heat transfer system having a compressor, condenser, expansion valve, evaporator and working fluid in a s fluid circuit. The mass flow is controlled using a quality sensor for the working fluid exiting the evaporator, and a high side pressure sensor. A control circuit is provided that monitors the quality sensor and the high side pressure sensor, and controls operation of the compressor, condenser fan and valve in response thereto. A flow reduction mode is used to reduce high side pressure at the valve inlet without excessive compressor cycling by changing the quality sensor setpoint when the high side pressure exceeds the condenser fan turn-on pressure but is less than the compressor disengage pressure.

Abstract: A system for diverting refrigerant into an auxiliary receiving vessel to reduce refrigerator system pressure during an incipient over-pressure condition to prevent activation of safety pressure relief valves and release of refrigerant into the atmosphere.

Abstract: In a heat pump system intended for cooling operation at lower ambient conditions, a control is provided for sensing the compressor discharge pressure and for alternately providing power to and removing power from the outdoor fan in response to the discharge pressure respectively exceeding or falling below a predetermined level. Power is provided to and removed from the motor by way of a solid state relay, and the periods in which power is removed are controlled so as to exceed those periods in which the power is applied to the motor. The fan motor is supported by journal bearings, and the periods of time in which power is removed from the motor during the cycling process is limited to 10 seconds such that the motor does not come to a complete stop, thereby ensuring proper lubrication thereto.

Abstract: A cooling apparatus includes a bypass provided to a path extending from a compressor to an expansion valve via a condenser, and a unit for controlling a ratio of a flow rate of a refrigerant of the path via the condenser to that of the bypass path, or a unit for varying an air volume of a fan of an outdoor unit for blowing the condenser so as to vary a capacity of the condenser. The degree of superheat of the refrigerant is measured at an exit of the evaporator, and an expansion valve is controlled in accordance with the measured degree of superheat.

Abstract: The present invention describes a method of controlling the head pressure in a refrigeration or air conditioning system in order to maintain the internal discharge pressure and discharge line pressure substantially equal. The method consists of the steps of measuring the suction pressure of the working fluid, calculating the internal discharge pressure of the working lfuid by multiplying the suction pressure by the internal pressure ratio of the compressor, measuring the discharge line pressure of the working fluid and then comparing the internal discharge pressure to the discharge line pressure. If the difference between the internal discharge pressure and discharge line pressure is greater than some allowable tolerance, the capacity of the condenser is adjusted to equalize these two pressures.

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: This invention provides a refrigeration system which includes in a closed loop connection a compressor for compressing a refrigerant into a condenser for condensing the compressed refrigerant into a liquid refrigerant, a control valve for controlling the discharge of the liquid refrigerant from the condenser into a reservoir, a sensor for measuring the temperature of the liquid refrigerant near the control valve, a fan for circulating air through the condenser, a sensor for measuring the ambient temperature of the airflow through the condenser and an electronic control system to control various functions of the refrigeration system, including the flow of the liquid refrigerant through the condenser as function of the temperature difference between the ambient temperature and the temperature of the liquid refrigerant. During operation, a minimal flooding of the condenser is always maintained, i.e.

Abstract: The present invention provides an air conditioning apparatus for automobiles equipped with a heat exchanger and a control method for the apparatus, by which the heat transfer area of the heat exchanger can be properly controlled to permit a stable cycle operation, even when the capacity of a condenser is relatively overly enhanced under a condition of the low atmospheric temperature. The apparatus and the control method are achieved with such an arrangement that either one or both of headers of a heat exchanger is provided with at least one refrigerant flow rate control valve capable of opening and closing refrigerant passages in each header, the heat exchanger has a refrigerant inlet provided in one header and a refrigerant outlet provided in the other header, and the control valve is opened and closed to change the number of the passages allowing the refrigerant to pass therethrough, for thereby changing the effective heat transfer area for heat exchange dependent on the atmospheric temperature.

Abstract: A condensing unit has a housing with a pair of compartments separated by a common wall. Within each compartment is a coil, a fan for passing air over said coil and a compressor operatively interconnected with the coil. There is an opening in the common wall that is opened and closed by a damper. The damper is rotatably or pivotally secured to the common wall to open and close the opening therein. A damper motor is provided for actuating the damper is response to attainment of a predetermined refrigerant pressure in the refrigeration system in the first compartment. Opening of the damper allows air to be drawn from the inoperative second compartment through the first compartment, resulting in a reduced pressure differential across the coil in the first compartment and a reduction in the air flow across the coil in the first compartment. With the reduced air flow, the pressure in the refrigeration system in the first compartment will rise to a predetermined level and the damper motor will be deenergized.

Abstract: An automotive air conditioning system includes a compressor with a variable displacement mechanism, a condenser, a decompression device and an evaporator serially arranged to form a closed refrigerant circulation path. A conduit connects an outer side of the compressor to an intermediate portion of a fluid conduit passing through the condenser. A pressure adjusting mechanism is disposed in the bypass conduit to adjust the pressure of refrigerant in the condenser. The pressure adjustment mechanism permits the automotive air conditioning system, which includes a compressor with a variable displacement mechanism, to maintain the amount of refrigerant circulated in the system at a desired level under small, as well as large, air conditioning loads.

Abstract: A refrigeration system employing a mechanical thermal expansion valve with a self-heated thermistor sensing saturation temperature at the high pressure inlet. A microprocessor based controller compares the sensed temperature with stored limits and provides output signals to a relay for cycling the condenser fan responsive to high side pressure means are provided for varying the current through the thermistor for operating same in the non-self heated mode to sense actual refrigeration temperature for generating a control signal to disable the compressor clutch when refrigerant temperature exceeds desired low limits.

Abstract: An air conditioning apparatus includes an external heat-exchanger having upper and lower side heat-exchanger elements, arranged in a vertical direction, each having a plurality of fluid pipes, upper and lower fan devices disposed opposite to corresponding heat-exchanger elements, and a temperature sensor disposed on one end (discharge side during cooling) of the upper-most fluid pipe of the upper side heat-exchanger element for outputting a detection signal indicating the condensation temperature of the external heat-exchanger corresponding to the condensation pressure of the external heat-exchanger. The rotation speed of the upper side fan device is regulated in accordance with the detection signal from the sensor to control the condensation pressure of the upper and lower side heat-exchanger elements within a prescribed range.

Abstract: A method and apparatus for electronically pressure sealing and leak testing an idle centrifugal chiller system wherein a small positive differential is maintained between the internal refrigerant vessel pressure of the chiller system and the ambient atmosphere. This differential pressure is maintained by selectively applying heat to the refrigerant.

Abstract: An improved refrigeration system that has an air cooled condenser exposed to outdoor ambient conditions and which automatically maintains sufficient head pressure during cooler weather for adequate liquid flow to the expansion valve of the evaporator by backflooding the condenser. Sub-cooling of the liquid in the condenser results from the backflooding and this sub-cooled liquid flows into the liquid line to the expansion valve. The liquid line out of the receiver joins the liquid line below the receiver so that the pressure in the receiver can be used to maintain the liquid level and the presence of liquid at the condenser. Means is provided to control the refrigerant pressure in the receiver in response to liquid level in the outlet line from the condenser.

Abstract: Start-up problems in an intermittently operated evaporative cooling system to low temperature environments is avoided by the provision of one or more heaters 62, 64, 66 in the system. Typically the system will include an evaporator 10, a compressor 24, a condenser 42, a receiver 62 and an expansion valve 56. When low ambient temperatures reduce internal pressure within the system to a value below which it can be started through operation of the compressor 24, the heaters 62, 64, 66 may be energized to vaporize refrigerant and thus generate a pressure of sufficient magnitude so as to allow starting.

Abstract: An improved refrigeration system that has an air cooled condenser exposed to outdoor ambient conditions and which automatically maintains sufficient head pressure during cooler weather for adequate liquid flow to the expansion valve of the evaporator by backflooding the condenser. Sub-cooling of the liquid in the condenser results from the backflooding and this sub-cooled liquid is diverted through a bypass line around the receiver to a sub-receiver and thereby to the liquid line to the expansion valve. In warmer weather, the liquid or a liquid and gaseous mixture from the condenser can enter the receiver or the bypass line. The liquid line out of the receiver forms a drop leg and joins the bypass line at the sub-receiver at a sufficient elevation below the receiver so that the pressure due to the static head at the sub-receiver is greater than the pressure at the receiver, said pressure difference causing any gaseous and liquid mixture from the condenser to flow to the receiver.

Abstract: An air-conditioning installation for motor vehicles, especially for passenger motor vehicles, in which the cooling medium circulation is adapted to be switched from cooling to heating by a flow direction reversal. For purposes of heating, a by-pass line which by-passes the expansion valve effective during cooling and which contains a pressure-holding valve, terminates in a multi-channel partial area of the cooling-condenser effective as heating-evaporator so that a high heat output is produced from the compression heat and from the additional heat pump effect.

Abstract: An outdoor air cooled condenser for a refrigeration installation having at least one refrigeration system circuit and including a condenser coil with a heat transfer surface, a condenser housing having air inlet and outlet means for the passage of air across said heat transfer surface, the outlet means including a primary outlet with air flow control means therefor and a plurality of secondary outlets with air displacement means and damper means associated therewith, sensing means for sensing a predetermined condition of refrigerant in the condenser coil, control circuit means for monitoring and integrating the sensed refrigerant condition with respect to a predetermined ideal condition set point value for the refrigeration system circuit and for operating the air flow control means and air displacement means for controlling the amount of air passing through the housing and across the heat transfer surface.

Abstract: An air-conditioning system for a vehicle is configured so as to adjust draft volume to a condensor for an air conditioner on the basis of the pressure of refrigerant circulated through a condensor and atmospheric temperature to optimize draft volume to be distributed to the condensor and the radiator. The air-conditioning system comprises a plurality of motor-fans for the condensor and the radiator, a refrigerant pressure sensor provided at the input and output of the condensor, an atmospheric temperature sensor, and an operational mode control unit responsive to the refrigerant pressure sensor and to the atmospheric temperature sensor.

Abstract: A control system for a compression type refrigeration unit with an air-cooled condenser exposed to outside ambient conditions. In cooler weather the head pressure is maintained by backflooding the condenser which limits the condensing surface. This also subcools the liquid in the condenser. A bypass line from a point between the outlet of the condenser and the receiver inlet connects with the liquid supply line leaving the receiver and directs this subcooled liquid to the expansion valve. A solenoid valve in the bypass line is controlled by a liquid level sensor or subcooling sensor in the line leaving the condenser. This increases the capacity of the evaporator as less evaporation is required to remove the sensible heat-down to the evaporating temperature. In warmer weather, the system automatically reverts to a conventional condensing mode.

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.

Abstract: The invention relates to an outdoor air cooled condenser for use in a refrigeration system and a method of controlling the condensing temperature in the condenser. The condenser may be used for one or several closed refrigeration circuits connected thereto. A condenser coil assembly is provided in the condenser and has a condenser coil and a heat transfer surface, the coil being connected to the refrigeration circuit. A housing houses the condenser and has an inlet and an outlet for the passage of air through the housing about the heat transfer surface. The outlet is divided in a primary outlet and a plurality of secondary outlets. A motor-driven fan is provided with each of the outlets. The primary outlet is provided with a controllable damper while the secondary outlets are provided with gravity-operated dampers.

Abstract: A vapor generating and recovery apparatus for vaporizing a liquid and condensing the vapor including at least one chamber in which vapor is generated from the liquid and recovering the vapor in liquid form, the vapor generating portion of the chamber being in heat emitting relation with a heat emitting means and the vapor recovery portion of the chamber being in heat absorbing relation with a heat absorbing means. A preferred system for providing heating and cooling to the vapor generating and recovery apparatus is a refrigerant system which includes at least one refrigerant condensing coil (heat emitting means) and at least one refrigerant evaporating coil (heat absorbing means) in heat transfer relationship with the vapor generating portion and vapor recovery portion, respectively, of the chamber, and two refrigerant heat exchanger means, one being downstream and one being upstream of the heat emitting means for removing excess heat from the refrigerant system.

Abstract: A refrigeration system comprises a main circuit including a compressor, a condenser, a main capillary tube, and an evaporator whereby a coolant is circulated through the main circuit to effect a refrigerating cycle, a bypass circuit including an auxiliary capillary tube the inlet side of which is connected to the high pressure side of the compressor, and an electromagnetic valve the inlet side of which is connected to the outlet side of the auxiliary capillary tube and the outlet side of which is connected to the low pressure side of the compressor, a circuit breaker switch acting to disconnect the main circuit when the pressure of the coolant reaches a first preset pressure, and a bypass switch acting to open the electromagnetic valve to cause part of the coolant from the outlet side of the condenser to flow through the auxiliary capillary tube and electromagnetic valve to the low pressure side of the compressor when the pressure of the coolant reaches a second preset pressure lower than the first preset pre

Abstract: A closed circuit refrigeration system includes a compressor, a remote condenser coupled to the output of the compressor, a receiver tank coupled downstream of the condenser means, and one or more evaporators coupled between the receiver and compressor return. A bypass conduit is coupled between the condenser output and receiver input at one end and between the receiver output and evaporator input at the other end; and a temperature controlled valve selectively controls the flow of refrigerant through the bypass conduit as a function of the temperature of refrigerant at the condenser output. A check valve in the condenser output conduit prevents backflow of refrigerant during periods of low condenser pressure. A method of operating a closed circuit refrigeration system is included in which a receiver tank bypass line is controlled responsive to the condition of the refrigerant in the condenser output.