Abstract: A two-step metering device for controlling the flow of an operating fluid to a variable capacity compressor is provided. The metering device includes a valve that defines a fluid flow path having a large orifice configured to allow a flow rate corresponding to a high operating capacity of the compressor and a small orifice configured to allow a flow rate corresponding to a reduced operating capacity of the compressor. The metering device further includes a control operable to adjust the valve to direct the operating fluid through the large orifice when the compressor is operating at the high capacity and to direct fluid through the small orifice when the compressor is operating at the reduced capacity.

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: 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: 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 improved efficiency economizer system for compressors incorporates the use of a check valve blocking return flow into the economizer return line. The economizer return line communicates with an economizer port, which communicates with a compression chamber. Pressure in the compression chamber can vary during the operational cycle of the compressor. Thus, in the past, there has sometimes been backflow of refrigerant through the economizer injection port and into the return line. The present invention prevents this backflow. Most preferably, the invention is utilized on scroll compressors; however, other types of compressors may benefit from this invention.

Abstract: An system and method for monitoring and limiting high power and overheating engine conditions in a transport refrigeration unit is disclosed. The system provides a microprocessor control which monitor the engine coolant temperature to determine whether it exceeds a predetermined limit. If the engine coolant temperature exceeds that limit, the control sends a control signal which restricts or closes the suction modulation valve of the transport refrigeration system, restricting the mass flow rate of the system and thereby reducing the power draw on the engine. The system further provides a continued monitoring process for further restricting or closing the suction modulation valve in the event of continued high engine coolant temperatures, and for gradually opening the suction modulation valve and increasing the maximum current draw on the engine once the engine coolant temperature sinks below its predetermined limit.

Abstract: A refrigeration cycle is switched from a refrigeration cycle circuit to a hot gas heater circuit to make the hot gas discharged from a compressor flow into an evaporator and heat the vehicle passenger compartment, at which time, when a suction pressure (Ps) of the compressor becomes a low pressure below a first predetermined pressure, the discharge volume (Vc) of the compressor is made larger to ensure a sufficient auxiliary heating performance. Further, when the hot gas is made to flow into the evaporator to heat the vehicle passenger compartment, if the suction pressure (Ps) of the compressor becomes a higher pressure over a second predetermined pressure, the discharge volume (Vc) of the compressor is made smaller to protect the refrigeration cycle parts and lighten the ON, OFF shock.

Abstract: A method of operating a refrigeration system in steady state operation drives the refrigerant system to the lowest capacity state which is still able to maintain operation within acceptable pressure and temperature limits. Generally, the system seeks to minimize the on and off compressor cycling. The lowest capacity state is achieved by throttling the compressor suction and by staging down the compressor operation from economized to normal and to unloaded mode while assuring that desired box temperature is maintained. Safety methods are incorporated into the system to ensure that the operation does not violate limits on suction pressure, discharge pressure, and compressor discharge temperature.

Abstract: A motor vehicle air conditioner control system that maintains a target cooling vent temperature without sacrificing vehicle engine performance. When a vehicle air conditioning compressor increases to above a predetermined speed and the vehicle engine driving force increases, such as during a period of engine acceleration, compressor cooling capacity becomes saturated and does not increase. When the speed of the compressor rises to a predetermined value and the compressor assumes a high-speed state, thereafter, while the compressor is in the high-speed state, operation of the compressor is controlled so as to sustain the vent-air temperature of an evaporator determined at a time when the high-speed state has been assumed. As a result, the amount of increase of the driving force due to this compressor speed increase is suppressed by reducing the volume of the compressor, thereby resulting in power savings while securing substantially maximum cooling capacity.

Abstract: An Improved Refrigeration System and Heating/Defrost Cycle is disclosed. The system, for heating circulating air and defrosting an enclosed area, includes a refrigerant, an evaporator using said refrigerant for heating the circulating air; and a compressor for receiving the refrigerant from the evaporator and compressing the refrigerant to a higher temperature and pressure. Advantageously, the system further includes the combination of an expansion valve positioned between the compressor and the evaporator for forming a partially expanded refrigerant, a controller for sensing system parameters, and a mechanism responsive to said controller, based on the sensed parameters, for increasing temperature differential between the refrigerant and the circulating air, for improving system efficiency and for optimizing system capacity during heating and defrost cycles.

Abstract: The present invention relates to a refrigerating system and a method of operating a refrigerating system. The refrigerating system includes a compressor, a gas cooler used as a heat-dissipation type heat exchanger, an expansion valve used as a throttling means, an evaporator used as a heat-absorption type heat exchanger and an accumulator, which are connected in series with each other to form a closed circuit. The closed circuit is adapted so that the higher pressure of the closed circuit becomes the supercritical pressure of a refrigerant circulating the closed circuit. This has a control characteristic property wherein the lower evaporating pressure increases as the higher pressure increases.

Abstract: At start up, at least one bank of cylinders of a compressor is allowed to compress gas and deliver the compressed gas to the system while at least the majority of the other banks are subject to hot gas bypass. The entire compressor is subject to suction modulation such that the amount of gas that can be compressed and delivered by all of the operating banks can be controlled and thereby the compressor power demand is controlled.

Abstract: A device for use in regulating the flow of a working fluid, such as a refrigerant, includes a body defining an axial opening, and a piston received within the axial opening. The piston is moveable in the body and has first and second ends. An actuator, which in one embodiment, is a stepper motor, is coupled to the first end of the piston for providing a force to the piston. An inlet and an outlet are coupled to the body such that the input, the output and the body define a passageway for the working fluid. An articulating seat assembly is coupled to the second end of the piston.

Abstract: A unique method of operating a refrigeration system for rapidly pulling down a refrigerated container temperature includes the use and algorithm for operating several system components. The refrigeration system is preferably provided with a suction modulation valve, a compressor unloader and an economizer circuit. By utilizing each of these components in combination with one another, and at various stages during the pull down capacity and energy efficiency of the refrigeration system are optimized, while maintaining the system operation within preset limits.

Abstract: Step control in capacity modulation of a refrigeration or air conditioning circuit is achieved by rapidly cycling a solenoid valve in the suction line, economizer circuit or in a bypass with the percent of "open" time for the valve regulating the rate of flow therethrough. A common port in the compressor is used for economizer flow and for bypass.

Abstract: An process and method for monitoring and selectively implementing an operator selected economy mode in a transport refrigeration system is disclosed. The system includes a microprocessor control which, in response to operator selection of the economy mode, increases the base superheat setting, lowers the engine speed, limits the system current, and reduces the compressor capacity in order to optimize the fuel consumption of the system. The controller further monitors for the presence of an out of range alarm, and issues override commands reversing the superheat, compressor, current limit and engine speed economy mode settings at least until the out of range condition no longer exists.

Abstract: A servo device for regulating a refrigerant into a compressor comprises a low pressure regulator, a high pressure regulator, and a solenoid valve. The low pressure regulator is connected to an inlet of the compressor and the high pressure regulator is connected to an outlet of the compressor. The solenoid valve is communicating with the low pressure regulator and the high pressure regulator respectively. The low pressure regulator further comprises a cylindrical plunger and a spring. The plunger is located in the low pressure regulator and the spring is located at lower end of the plunger to bias against the plunger. The plunger is pushed to move upward intermittently by a refrigerant coming from the high pressure regulator via the solenoid valve so that the refrigerant entering the compressor is hindered by the plunger to correspond with a state of optimal cooling in an air conditioning system or in a mechanical refrigeration system.

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 refrigeration system comprises an evaporator having an inlet and an outlet, a condenser, a compressor that is located between the evaporator and the condenser and that provides suction pressure at the evaporator outlet, an expansion valve that is connected to the evaporator inlet and that is operable to regulate a flow of refrigerant into the evaporator, a pressure regulator that is connected to the evaporator outlet and that is operable to limit the suction pressure to a regulated value, and a controller that coordinates operation of the pressure regulator with operation of the expansion valve.

Abstract: A centrifugal type refrigerant compressor comprises at least one impeller (17, 18), electric motor (27) and drive shaft (22) mounted on non-lubricated radial bearings, such as magnetic or foil gas bearings (23, 24), with axial locating means (26) associated with the shaft (22) to restrict axial movement thereof with respect to the compressor housing (12). The housing (12) encases the motor (27) and the compressor and defines the gas inlet (31) and the gas outlet (16) passageways. Gas throttling means (34) is provided in the inlet (31), and a control means (30) varies the speed of the motor (27) and the throttling means (34) to control the compression ratio and mass flow through the compressor in accordance with the refrigeration load.

Abstract: A receiver is located in a refrigerating circuit that includes a compressor, a condenser, an expansion valve and an evaporator. The receiver receives and temporarily reserves liquefied refrigerant sent from the compressor by way of the condenser. The expansion valve atomizes the liquefied refrigerant sent from the receiver and supplies the atomized refrigerant to the evaporator. The receiver includes a tank for reserving the liquefied refrigerant sent from the condenser and a head portion located on the tank. The head portion houses the expansion valve. The expansion valve includes a restricting mechanism for adjusting the flow rate of the refrigerant supplied to the evaporator from the tank and a control mechanism for controlling the restricting mechanism in accordance with the temperature of the refrigerant transferred to the compressor from the evaporator.

Abstract: A climate controller for an automobile, comprising a compressor and a receiver arranged in an engine compartment of the automobile, a condenser located at an outside-air inlet of the engine compartment, an expansion member and an evaporator disposed in a passenger compartment of the automobile, and a closed-loop refrigerant passage connecting the compressor, the condenser, the receiver, the expansion member and the evaporator in sequence for circulating a refrigerant through these components to establish a refrigerating cycle. The climate controller further includes a valve arranged in a part of the closed-loop refrigerant passage extending from the evaporator through the compressor to the condenser. The valve is actuated to intersect a communication of the refrigerant through the part of the passage when an operation affecting temperature of both the compressor and the condenser becomes ineffective, and to allow the communication when the operation becomes effective.

Abstract: An ice cream machine for cooling liquid ice cream into frozen ice cream includes an evaporator having a cylindrical cooling tank and an auxiliary tank. The auxiliary tank ensures that the cylindrical cooling tank is flooded with liquid refrigerant during normal operation. The flooding of the cylindrical cooling tank provides more efficient and even cooling in an interior cooling chamber. The more efficient cooling allows the ice cream machine to utilize a smaller compressor, thereby reducing the cost and energy consumption of the ice cream machine. The auxiliary tank can be a coil of tubing or a cylindrical container positioned above the cylindrical cooling tank.

Abstract: An air cooling and control system for a refrigerated food merchandiser having an insulated cabinet with a product are having adjacent product zones, plural modular evaporator coil sections of substantially equal heat exchange potential and being of predetermined length and arranged in horizontal, spaced, end-to-end predetermined disposition and separate air moving means associated with each coil section and a corresponding product zone for circulating separate air flows through the coil sections and to the product area for cooling. The system further includes a first refrigerant metering valve for controlling liquid refrigerant flow on the high side of the evaporator sections, and a second refrigerant metering valve for controlling suction pressure and refrigerant vapor flow on the low side of the evaporator sections. An electronic control senses exit air temperatures downstream of the evaporator sections and operates the second metering valve in response thereto.

Abstract: Both a system and method are provided for achieving temperature control in a refrigeration circuit by providing a bypass flow of saturated, gaseous refrigerant from the receiver tank to a point in the circuit downstream of the evaporator coil. The system includes a bypass conduit for conducting a bypass flow of saturated, gaseous refrigerant from an upper portion of the receiver tank to a point in the circuit between the evaporator coil and a suction line throttling valve to partially offset the cooling of the evaporator coil from the expansion valve. The bypass conduit includes a valve mechanism for modulating this flow to achieve a desired temperature setpoint. The system also includes a temperature monitoring sensor located in a space conditioned by the refrigeration circuit, as well as a microprocessor. The input of the microprocessor receives an electrical signal generated by the monitoring sensor indicative of the temperature of the space.

Abstract: A temperature control device for an electric motor vehicle passenger compartment, wherein a fluid coolant flows through an inner heat exchanger arranged in the path of an air flow to the passenger compartment, a first outer heat exchanger arranged in the path of an air flow out of the passenger compartment, and a second outer heat exchanger ?(42)! for exchanging heat with a heat source outside the passenger compartment. Said device may operate in heating mode or in cooling mode depending on the direction of flow of the fluid coolant. The device is useful in motor vehicles.

Abstract: A refrigerator unit provided with a control means comprising a plurality of valves, the control means comprising a unitary valve manifold made as a one piece casting having said valves operatively mounted thereon.

Abstract: An assembly for temperature control of a fountain (dampening) fluid and/or selected rolls of a printing press, comprising a first open-circuit circulating system (U.sub.I) for supplying a fountain fluid application mechanism with a fountain fluid from a fountain fluid reservoir and a second closed-circuit circulating system (U.sub.II) for supplying a roll cooling mechanism with a cooling fluid. Each circulating system (U.sub.I, U.sub.II) is assigned a heat exchanger (3,4). The heat exchangers (3,4) receive refrigerant from a refrigeration mechanism having a power-switchable compressor (10) including a refrigerant return, thus enabling a refrigeration output to be adapted to demands in selectable operating modes "fountain-fluid cooling only", "cooling-fluid cooling only" or "fountain-fluid and cooling-fluid cooling".

Abstract: A refrigeration system, particularly for controlling the temperature of an environment, and presenting a compressor; a condenser; a laminating thermostatic valve; an evaporator; an evaporation pressure control valve interposed between the outlet of the evaporator and an inlet of the compressor; an economizer in turn presenting a laminating orifice downstream from the condenser, and a flash tank with an inlet communicating with the orifice, a liquid-phase outlet connected to the thermostatic valve, and a gaseous-phase outlet connected to an intermediate inlet of the compressor; and a tapping valve interposed between the outlet of the compressor and the flash tank, and which is opened when the pressure in the flash tank falls below a predetermined threshold value.

Abstract: A method of controlling refrigerant pressure during elevated ambient temperature conditions in a refrigeration unit having a refrigerant compressor driven by a prime mover, and controllable suction line modulation. The method includes the steps of detecting the actual load PML on the prime mover, sensing the ambient temperature AA, and providing a dynamic load limit DLL as a function of the ambient temperature AA. The actual load PML is compared with the dynamic load limit DLL, and the suction line modulation is changed as a function of the comparison step to cause the actual load PML to follow the changing dynamic load limit DLL. The invention also includes a method of preventing excessive on-off cycling of a refrigeration unit during low ambient temperature conditions, with the refrigeration unit operating in a cycling start-stop mode to control the temperature of a conditioned space to a selected set point temperature SP.

Abstract: A heat pump type air conditioning system comprises an air duct in which air flows in a given direction with an aid of an electric air blower. A condenser is disposed in the air duct. A compressor has an outlet connected to an inlet of the condenser. A receiver dryer has an inlet connected to an outlet of the condenser. An outside expansion valve has an inlet connected to an outlet of the receiver dryer through a first passage. An outside evaporator has both an inlet connected to an outlet of the outside expansion valve and an outlet connected to an inlet of the compressor through a second passage. An inside evaporator is disposed in the air duct at a position upstream of the condenser. An inside expansion valve has both an inlet connected to the first passage and an outlet connected to an inlet of the inside evaporator.

Abstract: A method of controlling the operation of a centrifugal compressor in a water chiller system. The compressor's capacity is variable by modulating its speed of rotation or by modulating its inlet guide vane's position. The water chiller includes an evaporator having a leaving water temperature. The method comprises the steps of: monitoring the leaving water temperature; determining if the leaving water temperature is in a steady state; modulating the compressor capacity by modulating speed of rotation if the leaving water temperature is in a steady state; and modulating the compressor capacity by modulating inlet guide vane position if the leaving water temperature is not in a steady state.

Abstract: A method of controlling the operation of a centrifugal compressor in a water chiller system. The compressor's capacity is variable by modulating its speed of rotation or by modulating its inlet guide vane's position. The water chiller includes an evaporator having a leaving water temperature. The method comprises the steps of: monitoring the leaving water temperature; determining if the leaving water temperature is in a steady state; modulating the compressor capacity by modulating speed of rotation if the leaving water temperature is in a steady state; and modulating the compressor capacity by modulating inlet guide vane position if the leaving water temperature is not in a steady state.

Abstract: A thermal control system in which a boiling liquid refrigerant is vaporized by heat addition from the system electronics. The pressure on the boiling liquid refrigerant and the vaporized refrigerant thereover is maintained constant so that the temperature of vaporization is maintained constant. For this reason, the boiling liquid refrigerant rapidly vaporizes and concomitantly removes from the system the very large amount of heat required for the refrigerant to pass from the liquid to the gaseous phase. The heat transfer rates under these conditions are extremely high. In addition to heat addition to the liquid before vaporization, the mass of liquid vaporized absorbs heat during vaporization of the liquid. The transition from liquid to vapor occurs at a constant temperature which is controlled by controlling the pressure at which the vaporization takes place.

Abstract: A thermostatic expansion valve includes a valve housing having upper and lower passages. In the lower passage a valve member urged by a spring toward a valve seat of a valve port formed therein is provided. At the top of the housing a driving unit for driving the valve member to open and close the port is attached. The unit has a housing partitioned by a diaphragm into upper and lower pressure operating chambers. A diaphragm driving fluid is filled in the upper chamber, and the lower chamber is connected to a refrigerant circulating pipe between an evaporator pressure regulator and a compressor while the upper passage to the pipe between an evaporator and the regulator and the lower passage to the pipe between the evaporator and an condenser. In the housing a valve member driving rod extends from the diaphragm to the port and crosses the upper passage. The top end of the rod is hermetically fixed to the diaphragm and the lower end abuts the valve member against the spring.

Abstract: A refrigeration system which controls the temperature of a conditioned space to a predetermined temperature range adjacent to a selected set point temperature SP via a cooling cycle which includes evaporation a cryogen, such as CO.sub.2 or N.sub.2, in a heat exchanger. In an apparatus embodiment, a controller determines a desired evaporation vapor pressure value EPX of the cryogen as a function of the selected set point temperature SP, and then controls the evaporation pressure EP in the heat exchanger means as a function of the determined desired evaporating vapor pressure value. The controller further determines a desired superheat value SHX of the cryogen exiting the heat exchanger means as a function of the selected set point temperature SP, and controls the mass flow rate of liquid cryogen evaporating in the heat exchanger as a function of the determined desired superheat value.

Abstract: A method of operating a refrigeration system having a compressor driven by an engine, with the refrigeration system being operable in a first control mode to hold the temperature of a conditioned space at a selected set point temperature, and in a second control mode to maintain the engine in a ready-to-start condition. The second control mode includes monitoring the ambient temperature, and determining a dynamic set point temperature as a function of ambient temperature. The engine is started and stopped to maintain engine startability, and also as a function of the dynamic set point temperature, to maintain the temperature of the conditioned space at the dynamic set point temperature while maintaining the engine in a ready-to-start condition. Control is changed from the second to the first control mode, when a programmed start feature is activated, with the time of such mode change being a function of the difference between the ambient temperature and the selected set point temperature.

Abstract: A temperature-controlled environmental chamber includes a resistance heater powered through a first solid state relay and a refrigeration unit including an electrically powered thermally controlled suction throttling valve connected in the refrigerant line between the evaporator and the inlet of the compressor, and including a bimetal motor and a heating element therefor powered through a second solid state relay. A thermostat senses the temperature in the chamber and compares it to a set point temperature and outputs a pulse-width modulated control signal indicative of the difference between the two temperatures. The control signal directly controls the heater relay for substantially continuous variation of the heater between minimum and maximum heating conditions.

Abstract: The present inventions are intended to improve heat efficiency of a refrigeration system having plural refrigerating cycles of different evaporating or condensing temperatures typically used in breweries. Each of main lines of different evaporating temperatures are connected with each of suction lines to a compressor respectively, to enable the system to save energy and to establish a back-up system of compressors. A different condensing temperature system having a common refrigerant source is provided with refrigerant transferring means to transfer refrigerant from an refrigerant excess cycle to an refrigerant insufficiency cycle.

Abstract: A temperature-controlled environmental chamber includes a resistance heater controlled by a solid state relay and a refrigeration unit including an electronically controlled suction throttling valve connected in the refrigerant line between the evaporator and the inlet of the compressor. A temperature controller senses the temperature in the chamber and compares it to a set point temperature and outputs a pulse-width modulated control signal indicative of the difference between the two temperatures. The control signal directly controls the heater relay for substantially continuous variation between minimum and maximum heating conditions. The control signal is converted to an analog signal for controlling the throttling valve of the refrigeration unit for substantially continuous variation between maximum and minimum cooling conditions, so that the amount of cooling provided is inversely proportional to the amount of heating provided.

Abstract: A refrigerant flow switching device for alternatively conveying flow of refrigerant from either a high pressure or a low pressure evaporator to a compressor of a refrigeration system and a refrigerator using such a refrigeration system. The device utilizes the pressure difference between the higher pressure refrigerant from the high pressure evaporator and the lower pressure refrigerant from the low pressure evaporator or atmospheric pressure to open and close a first flow controller of the device positioned in a conduit leading from the high pressure evaporator to the compressor. The device further comprises a second flow controller, such as a check valve positioned in a conduit leading the low pressure evaporator to the compressor, which stays open only when the first flow controller is closed.

Abstract: An oil recovery system for a closed type centrifugal refrigerating machine. The refrigerating machine includes a compressor that has an oil sump below the suction side thereof, a condenser that liquefies compressed refrigerant gas by cooling, an evaporator that evaporates the liquefied refrigerant, a suction volume control valve that controls the volumetric flow of refrigerant gas sucked into the compressor from the evaporator, recovery means for recovering oil from the oil sump to an oil tank in a lubricating system, and control means for starting or stopping the compressor in accordance with the magnitude of refrigeration load. The oil recovery system comprises valve opening control means for controlling the opening of the suction volume control valve such that a decrease in the amount of oil recovered to the oil tank is compensated for when the number of times of start or stop of the compressor per unit of time exceeds a set number.

Abstract: A condenser (2), an electronic expansion valve (5), an evaporator (6), and a motorized suction throttle valve (8) are connected in series with a compressor. When a capacity is increased, the electronic expansion valve (5) is controlled to be in a throttling direction and the motorized suction throttle valve (8) is controlled to be in an unthrottling direction in association with the control of the electronic expansion valve (5), and when a capacity is decreased, the electronic expansion valve (5) is controlled to be in an unthrottling direction and the motorized suction throttle valve (8) is controlled to be in a throttling direction in association with the control of the electronic expansion valve (5). While a capacity control of a compressor by a throttle control is been carried out, such associated control is made between the electronic expansion valve (5) and the motorized suction throttle valve (8), realizing a fine temperature control in a refrigerating machine without hunting.

Abstract: An economizer arrangement for ice making reverse cycle refrigeration system of the type employing hot-gas defrosting, including a condenser, a receiver to receive liquid refrigerant, a plural tube evaporator having an internal refrigerant chamber in each tube and an expansion valve through which the refrigerant flows into the evaporator tubes during a freezing cycle of the system to cause ice formation on ice-making surfaces of the evaporator means in heat exchange relation with the refrigerant chamber. A rotary screw type compressor supplying to the condenser and has an economizer port at a location along the screw where the pressure builds up to a selected level, a refrigerant valve passes the condenser and routes hot-gas refrigerant during a harvest defrost cycle to the evaporator tubes, and a relief conduit tube communicates the refrigerant chambers of the evaporator tubes with the economizer port.

Abstract: A refrigeration system control for a refrigerated container unit in which a compressor suction modulating valve is controlled during light loads near its valve seat by rapidly moving the suction modulating valve to an open position away from the valve seat and then moving the suction modulating valve to the desired position.

Abstract: Electric expansion valves are provided midway along liquid-side pipes connected to indoor units. Electric flow control valves are provided midway along gas-side pipes connected to the indoor units. The indoor units detect air-conditioning loads, and a capability of a compressor is controlled in accordance with the sum of the air-conditioning loads. At the same time, the opening degrees of the flow control valves are controlled in accordance with the individual air-conditioning loads of the indoor units. In the heating operation mode, a high-pressure-side pressure of a refrigeration cycle is detected. When the high-pressure-side pressure becomes a preset value or more, an expansion valve and a flow control valve corresponding to an indoor unit whose operation is stopped are opened to predetermined opening degrees.

Abstract: A refrigeration system includes a rack or bank of compressors located in parallel and feeding a common condenser. Liquid refrigerant from the condenser is supplied to a plurality of evaporators located in parallel and feeding a common suction manifold. The suction manifold is connected to the compressors and contains a valve for selectively isolating one or more compressors and evaporators whereby the isolated compressor acts as a satellite compressor and the isolated evaporators are operated at a lower temperature than the other evaporators.

Abstract: A refrigeration and defrost system utilizing various valves for opening a defrost line to hot gas and regulating the pressure in refrigerant lines. A slug surge suppressor is provided at several points in the defrost and refrigerant lines to eliminate hydraulic shock damage caused by slugs of a liquid-gas mixture passing rapidly through the lines. The slugs are generally formed by the required rapid opening of a hot gas defrost valve and a pressure regulatory valve of the system. A series of capillary passages in the suppressor are operative to resist the flow of liquid while allowing gas to flow freely. Tangential velocity is imparted to the slug to separate the liquid and gas components of the slug.

Abstract: A refrigerator apparatus is provided having a cabinet with a freezer compartment and a fresh food compartment. A refrigeration system is included having a first expansion valve, a first evaporator situated in the freezer compartment, a first and second compressor, a condenser, a second expansion valve, and a second evaporator situated in the fresh food compartment all connected together in that order and in series in a refrigerant flow relationship. First and second fans are provided in the freezer and fresh food compartments, respectively. A servovalve is connected between the first evaporator and the first compressor for reducing refrigerant flow through the first evaporator when activated. A first thermostatic controller situated in the freezer compartment causes operation of the compressors and fans when a selected temperature in the freezer is exceeded. A second thermostatic controller situated in the fresh food compartment causes operation of the servovalve when a predetermined value is reached.