Abstract: A multi-circuit refrigerant system incorporates at least one component provided with a pulse width modulation control. This component can be controlled to adjust the capacity provided by the circuit incorporating the component. In this manner, the pulse width modulation component can be controlled to exactly tailor the capacity of that circuit to provide a total desired combined cooling capacity of the multiple circuits within the multi-circuit system configurations. In one embodiment, only one circuit in a multi-circuit refrigerant system incorporates a pulse width modulation controlled component. In another embodiment, a plurality of circuits are provided with pulse width modulation controlled components.

Abstract: An air-conditioning system includes a refrigeration cycle and a control unit. The refrigeration cycle includes an electric compressor in which a compression mechanism for drawing a refrigerant therein for compression is integrated with an electric motor for driving the compression mechanism, and a motor drive circuit for driving the motor is cooled using an intake refrigerant drawn into the compression mechanism. The control unit provides operational control to the motor drive circuit and the refrigeration cycle. When the temperature of the motor drive circuit has exceeded a predetermined temperature, the control unit varies a condition of supplying air to exchange heat with the refrigerant flowing through the refrigeration cycle to thereby reduce the temperature of the intake refrigerant.

Abstract: A system for controlling one or more components of a climate control system is provided that includes one or more controllers in connection with low voltage power lines for powering the one or more controllers. The controllers are further capable of transmitting one or more communication signals via the low voltage waveform. The system includes a thermostat controller, at least one system controller for a heating or cooling system, and a controller for a circulating air blower. The thermostat controller, system controller and circulating air blower controller are connected to each other only through each controller's individual connection to the hot and common low voltage power transmission lines. Each controller is capable of transmitting one or more signals that are superimposed onto the low-frequency low-voltage waveform and include information identifying a destination controller that the signals are intended for.

Abstract: A cooling apparatus for objects such as convenience foods and beverages has an enclosure and a vapour cycle refrigeration system. The refrigeration system includes a compressor, a condenser, a metering device and an evaporator, all connected in a circuit. Fans force air across the evaporator coils during operation of the compressor. When the compressor is ‘off’, or dormant, the evaporator fans are operated in a partial or reduced duty cycle in which the overall power draw and average power consumption is less than it would be if the evaporator fans were run continuously.

Abstract: A freezer provides multiple zones of temperature for preserving a frozen product at an ultra-low temperature. At least one first housing provides a first interior space at a first predetermined temperature. A first compressor, condenser and metering device supply a first refrigerant to a first evaporator for lowering the temperature in the first interior space to the first predetermined temperature. At least one second housing is mounted totally within the first interior space and provides a second interior space for defining a second freezing zone at a second predetermined temperature. The second predetermined temperature is lower relative to the first predetermined temperature. A second compressor, condenser and metering device supply a second refrigerant to a second evaporator for freezing the second housing to the second predetermined temperature. The second compressor, condenser and metering device are disposed within the first interior space to the first evaporator.

Abstract: A real-time monitoring system that monitors various aspects of the operation of a refrigerant-cycle system is described. In one embodiment, the system includes a processor that measures power provided to the refrigerant-cycle system and that gathers data from one or more sensors and uses the sensor data to calculate a figure of merit related to the efficiency of the system. In one embodiment, the sensors include one or more of the following sensors: a suction line temperature sensor, a suction line pressure sensor, a suction line flow sensor, a hot gas line temperature sensor, a hot gas line pressure sensor, a hot gas line flow sensor, a liquid line temperature sensor, a liquid line pressure sensor, a liquid line flow sensor. In one embodiment, the sensors include one or more of an evaporator air temperature input sensor, an evaporator air temperature output sensor, an evaporator air flow sensor, an evaporator air humidity sensor, and a differential pressure sensor.

Abstract: A refrigeration system including an evaporator, a suction header in fluid communication with the evaporator, a compressor in fluid communication with the suction header, and a condenser in fluid communication with the compressor and the evaporator. The refrigeration system further including a controller operable to control the compressor and a sensor coupled to the compressor. The sensor is operable to acquire a parameter for the compressor. The method of operating the refrigeration system includes acquiring a value for the parameter with the sensor, and determining if the sensor is faulty.

Abstract: An air-conditioning system for a motor vehicle includes a coolant circuit, through which it is possible to pump coolant with the aid of a compressor, the air-conditioning system having a torque-determining unit for determining a drive torque required for operating the compressor as a function of a temperature of air, which has flowed past an evaporator integrated into the coolant circuit for evaporating coolant, a pressure of the coolant prevailing in the coolant circuit in front of the compressor relative to a flow direction of the coolant or an actuating signal for setting a settable compressor stroke of the compressor.

Abstract: A heat pump is provided with a component that has a pulse width modulation control to adjust system capacity. Thus, by utilizing a pulse width modulation technique to control this component, the present invention is able to closely tailor the delivered capacity of the heat pump to that which is demanded, without cycling the unit. In one embodiment, the component has a suction pulse width modulation valve. In another embodiment, the component which is modulated is the compressor pump unit, and, in particular, a pair of scroll members that are allowed to move into and out of contact with each other. The pulse width modulation control device can also be utilized in combination with a heat pump having an economizer function and/or an un-loader function.

Abstract: A variable restrictor including a tube with first and second ends of a first cross-sectional area and a region between the ends of reduced cross-sectional area. The region comprises a flattened portion of the tube where the tube has been permanently deformed such that opposed wall portions of the tube are much closed together than in the remainder of the tube. An actuator is arranged to selectively alter the separation of the opposed wall portions of the flattened section.

Abstract: Systems and methods are provided for a variable cooling capacity cryocooler for a superconducting magnetic resonance imaging device having a liquid cryogen pressure vessel to provide cryogenic temperatures to a magnet assembly, a vacuum vessel surrounding the pressure vessel and a radiation shield spaced from the cryogen pressure vessel, and a pressure sensor positioned inside the cryogen pressure vessel pressure boundary for sensing pressure variations. A controller for varying the heat removal rate of the cryocooler based on the pressure variations in the cryogen pressure vessel and where the cooling capacity of the cryocooler is adjusted by modifying the speed of the electric power drive (DC or AC motors) or by changing the mechanical transmission ratio between the constant speed electric power drive and the cryocooler displacer/piston to adjust the cooler oscillating frequency of the gas flow.

Abstract: A refrigerant system operates with tandem compressors (22, 24). A control (41) for the refrigerant system is operable to change the capacities of each of the compressors dependent upon a load on the system. The control determines the percentage of maximum load capacity currently being utilized by each of the compressors. A compressor with the highest percentage is decreased in capacity should the control determine that excess capacity is being provided. Conversely, the control will increase the capacity of a compressor having a lower percentage, if insufficient capacity is being provided to meet a load on the system.

Abstract: When a switching signal to switch the mode to the defroster mode is generated and the target air volume is smaller than a predetermined air volume ?, the target air volume is automatically increased to the predetermined air volume ?. In doing so, an increase starting point of time of increasing the target air volume is determined according to the blowout mode immediately before a switch signal to switch the mode to the defroster mode is generated.

Abstract: An apparatus and method for compressing gas refrigerant using two different compressors operated alternatively in a series or parallel mode for obtaining two different compression ratios and thereby provide efficient operation for both a relatively lower suction pressure and a relatively higher suction pressure. This system avoids an unbalanced mass flow rate when the compressors are operated in series by unloading a downstream one of the compressors. When operated in the series mode, refrigerant is bypassed back to a suction inlet of the downstream compressor during a portion of a compression stroke of the downstream compressor for equalizing the mass flow rate through the two compressors.

Abstract: To provide a multistage compressor including an injection circuit, which can continue high-efficiency and high-capacity operations even if the injection circuit is turned on/off in accordance with operating conditions. A multistage compressor includes a high stage side compressing mechanism suctioning the intermediate pressure refrigerant gas compressed with a low stage side compressing mechanism to perform two-stage compression, and an injection circuit for injecting an intermediate pressure refrigerant into the intermediate pressure refrigerant gas suctioned to the high stage side compressing mechanism, the high stage side compressing mechanism including a capacity control mechanism for bypassing a refrigerant gas that is being compressed to a suction side, the injection circuit including an on/off mechanism for performing on/off control of refrigerant injection, and the capacity control mechanism and the on/off mechanism being operated in conjunction with each other.

Abstract: A method and apparatus is disclosed for setting energy saver sleep modes for use in a centrifuge systems. The centrifuge system contains an energy saver touch screen control which can be either manually set or automatically set to turn the centrifuge on or off at predetermined times. This allows the centrifuge system to be readily available to a user, resulting in lower wear and tear being placed on the major systems of the centrifuge and waste less energy.

Abstract: A self-contained climate control system for simultaneous temperature and humidity control in a wine cellar includes a refrigeration system having a conventional vapor-compression system including a condensate drip tray with over-flow passages. A programmable controller with a temperature sensor turns the compressor on and off by responding to the temperature sensor to regulate the air temperature in the wine cellar. The programmable controller keeps the system fans running after the compressor stops to cause evaporation of the water in the drip tray, restoring the moisture to the wine cellar.

Abstract: A turbine for generating power has a rotor chamber, a rotor rotatable about a central axis within the rotor chamber, and at least one nozzle for supplying a fluid from a fluid supply to the rotor to thereby drive the rotor and generate power. The flow of the fluid from the nozzle exist is periodically interrupted by at least one flow interrupter means, thereby raising a pressure of the fluid inside the nozzle. A thermo-dynamic cycle is also disclosed including a compressor, a first turbine downstream of the compressor, a heat exchanger located downstream of the first turbine and operable to reject heat from the cycle to another thermodynamic cycle, an evaporator downstream of the heat exchanger and a second turbine downstream of the evaporator and upstream of the compressor.

Abstract: An air conditioner for automotive vehicle use intended to prevent a defrosting operation in an instantaneous foot-defroster mode. The DEF mode in which air mainly from a DEF opening is blown toward the windshield is set by an exclusive front DEF switch. The F/D mode for blowing a substantially equal amount of air to the windshield and the feet of the occupants from the DEF opening and the FOOT opening, respectively, together with the other blow modes (FACE, B/L, FOOT), are sequentially switched for each operation of the blow mode switch in a predetermined sequence. In the case where the F/D mode is selected, the air condition control operation is not performed nor is the blow mode displayed in F/D mode before the lapse of a predetermined length of time (about 1 second). In the case where the blow mode other than F/D mode is desired, therefore, the unrequired control operation in F/D mode is not performed and the instantaneous change is not displayed even though the F/D mode is unavoidably passed-through.

Abstract: An inverter 6 that drives an electric motor 4 of the electric compressor 3 operates in a protection-against-overheat mode, in which the electric motor is driven at a rotational speed for protection against heat different from a rotational speed specifying value from an air conditioning control unit 20, in order to ensure the flow rate of the refrigerant and cool the inverter itself when the temperature detected by an inverter temperature sensor 22g exceeds a predetermined value. At this time, if the refrigerant pressure increases or the evaporator discharge temperature falls, the air conditioning control unit stops the protection-against-overheat mode operation of the inverter and directs the inverter to forcedly stop the electric motor. Due to this, an excessive increase in the refrigerant pressure and evaporator freezeing can be prevented, and thus the function of the refrigerating cycle can be protected.

Abstract: An apparatus, method, and system for automatically turning off an electrically powered actuator in a refrigeration mechanism upon detection of an unwanted condition. In one aspect of the invention, the electrically powered actuator can be the motor of an ice maker/dispenser. The detection can be accomplished by sensing the presence of an object along or near an ice dispensing pathway from the ice maker/dispenser. The unwanted condition could be the presence of the object for more than a preset time period. This would allow to distinguish between an unwanted object such as silverware or clogged ice versus a wanted object such as flowing ice cubes, crushed ice, or shaved ice.

Abstract: A control system for a cooling system includes a first sensor for sensing a property indicative of demand for cooling and a controller coupled to the sensor. The controller produces the variable duty cycle control signal in response to the property and causes the compressor and valve to vary a cooling capacity of the cooling system in response to the variable duty cycle control signal. The sensor may sense the pressure, temperature, or both. The valve may be a suction-side pressure regulator or a liquid-side expansion valve of the solenoid or stepper type.

Abstract: A single medium voltage starter box is mounted on a chiller unit with the other components of the chiller system. The starter box can be positioned on the chiller system unit to permit the starter box to be close coupled to the motor, and specifically to the main motor lead exit hub without the need for any power conduit connections between the starter box and the motor. In addition, the starter box also does not require any control interface and receives controls from a control panel. A short conduit connection between the control panel and the starter box is used to provide the necessary connections between the control panel and the starter box.

Abstract: An apparatus for controlling an operation of a reciprocating compressor includes a inductance increasing device connected to a motor of the reciprocating compressor, so that a surge current generated when power is applied to the reciprocating compressor at an initial stage is reduced and thus an initial stroke of the reciprocating compressor is reduced. Accordingly, operational efficiency of the reciprocating compressor is improved.

Abstract: A rotary compressor includes a cylinder to form a first compressing chamber and a second compressing chamber partitioned from each other and including a first vane slot and a second vane slot which are formed in the first compressing chamber and the second compressing chamber, respectively, and a first roller and a second roller to respectively rotate in the first compressing chamber and the second compressing chamber to compress compressing media, the rotary compressor operating in a full load running mode in which a load running is concurrently performed in the first compressing chamber and the second compressing chamber, and in a partial load running mode in which a load running is performed in only the second compressing chamber, the rotary compressor further including a first vane which is controllably accommodated in the first vane slot, a vane driving part to enable the first vane to contact and be distanced apart from an outer surface of the first roller to perform a load running and a no-load running

Abstract: A multiphase current supplying circuit according to the present invention includes a diode bridge, an intervening circuit, an inverter, a control circuit, and a lightning arrester. The diode bridge is connected to a single-phase AC power supply system via the lightning arrester, and performs full-wave rectification on a single-phase AC voltage. The intervening circuit includes a capacitor and an inductor, and is constituted by a choke input type low-pass filter. More specifically, one end of the inductor and one end of the capacitor are connected, output from the diode bridge is received between the other end of the inductor and the other end of the capacitor, and a rectified voltage generated at both ends of the capacitor is output to the inverter.

Abstract: A method of providing variable cooling includes operating a cooling element to cool an air flow by a first cooling capacity, operating a heating element to heat the air flow by a first heating capacity that adjusts the first cooling capacity towards a first desired total cooling capacity, determining a second desired total cooling capacity, controlling the cooling element to cool the air flow by a second cooling capacity that is greater than the second desired total cooling capacity, and controlling the heating element to heat the air flow by a second heating capacity that adjusts the second cooling capacity towards the second desired total cooling capacity. Further embodiments and cooling systems are also disclosed.

Abstract: A system and method in a commercial refrigeration system for compensating for events. A commercial refrigeration system includes a controller that predicts a first change in cooling capacity required based on at least one anticipated system event. The controller also predicts a second change in cooling capacity required based on at least one anticipated system event during a period of time. The controller compares the first and second changes in cooling capacity and implements a change in cooling capacity based on a relationship between the first and second changes in cooling capacity.

Abstract: A single medium voltage starter box is mounted on a chiller unit with the other components of the chiller system. The starter box can be positioned on the chiller system unit to permit the starter box to be close coupled to the motor, and specifically to the main motor lead exit hub without the need for any power conduit connections between the starter box and the motor. In addition, the starter box also does not require any control interface and receives controls from a control panel. A short conduit connection between the control panel and the starter box is used to provide the necessary connections between the control panel and the starter box.

Abstract: In a communication network system which unifies a system communication network and a master system communication network, each of a plurality of controlled devices is configured to transmit status data to a master controller and receive control data from the master controller so that the controlled device is operated based on the control data. The master controller comprises a control unit configured to receive status data of the controlled devices and transmit control data to the controlled devices, the control unit being configured to transmit the status data to a system controller and receive the control data from the system controller. The system controller comprises a second control unit configured to receive the status data of the controlled devices from the master controller, perform a processing operation based on the status data, and transmit a result of the processing operation to the master controller as the control data.

Abstract: Method of controlling a pulse tube cryocooler in which the power input to the acoustic source is varied to maintain temperature of a refrigeration load or a temperature that is at least referable to the temperature of the refrigeration load, at a set point temperature. Additionally, the impedance of an inertance network of the pulse tube cryocooler is also adjusted to obtain a maximum cooling power to the refrigeration load at the particular temperature as sensed and the particular power that is being supplied to the acoustic source.

Abstract: A control system for a steam turbine driven chiller unit is provided. The control system automatically utilizes the full range of the governor, compressor pre-rotation vanes, and hot gas bypass valve capabilities to control the capacity of the chiller and provide anti-surge and override control functions to prevent undesirable operational ranges while maintaining maximum efficiency of operation.

Abstract: A method for controlling a start-up operation of an air conditioner having a compressor and an indoor and an outdoor fan includes the steps of: (a) calculating indoor cooling/heating load; (b) calculating a reference operating frequency of the compressor; (c) driving the indoor and the outdoor fan during a first time period to thereby adjust pressure equilibrium between an indoor and an outdoor pressure; (d) driving the compressor during a preset time period while increasing an operating frequency of the; and (e) setting the operating frequency of the compressor to the reference operating frequency and driving the compressor. The operating frequency of the compressor is increased in a stepwise manner during the preset time period and kept to be lower than the reference operation frequency throughout the preset time period.

Abstract: A refrigeration system including a compressor, condenser, valve, and refrigeration branch, all of which is in fluid communication. The refrigeration branch includes an evaporator coil. The refrigeration system further includes a case adapted to be cooled by the evaporator coil, and a system controller operable to control one or more aspects of the refrigeration system, and a subsystem controller in communication with the system controller. The subsystem controller is operable to control a subsystem having one of the compressor, condenser, valve, refrigeration branch, and case. The method of operating the refrigeration system includes at the subsystem controller, monitoring a parameter of the subsystem, comparing the monitored parameter with a parameter limit, generating an alarm when the parameter is not within the parameter limit, and communicating the alarm to the system controller.

Abstract: The present invention provides methods and apparatuses that support the transfer of data from a thermostat unit to a controller unit to control a variable speed heating, ventilation, and air conditioning (HVAC) system. The duty cycle of a signal (that is sent from a thermostat unit to a controller unit) is adjusted in accordance with a temperature difference between the ambient temperature of an environmentally controlled space and a set temperature. The controller unit measures the duty cycle to determine the temperature difference and adjusts the speed of a blower motor or compressor in accordance with the temperature difference. The signal is switched on and off, in which the AC waveform is conducted and blocked by the thermostat unit and received by the controller unit. The controller unit measures the duty cycle of the received signal, determines the temperature from the duty cycle, and adjusts the speed from a predetermined relationship.

Abstract: In a motor vehicle with a combustion engine, an electronic engine-management device, and an air-conditioning system with an air-conditioning control device, the air-conditioning compressor has reciprocating pistons whose displacement stroke is adjustable through one or more control valves. The electronic engine-management device has direct access to and priority control over the adjustment of the piston stroke, so that the electronic engine management device takes precedence over the air-conditioning control device in controlling the adjustment of the piston stroke.

Abstract: A control system and method are provided for the controlling of steam supplies used by a steam turbine driven chiller unit. The steam turbine can receive steam from a high pressure steam source and/or a low pressure steam source depending on the operating mode of the steam turbine. The high pressure steam is used for operating at the steam turbine at rated speed and to provide the breakaway torque when starting the steam turbine. The low pressure steam is used for extending idling of the steam turbine that enables the steam turbine to transition more quickly to rated speed when desired.

Abstract: A power saving apparatus is applied in a temperature regulator. The temperature regulator comprises a compressor. The power saving apparatus is electrically connected to the temperature regulator. The power saving apparatus comprises a sensor, a processing unit and a switching unit. The sensor is for sensing temperatures to generate a sensing signal. The processing unit is connected to the sensor for receiving the sensing signal to generate a switching instruction. The switching unit switches the compressor into an operation status or a silence status based on the switching instruction.

Abstract: A refrigerated appliance that dispenses items for use with a power source and includes a cooling system. Power control circuitry is electrically coupled between the power source and components (for example, a compressor and one or more circulating fans of the cooling system) of the appliance. A controller, which is operably coupled to the power control circuitry, is adapted to manage the supply of electrical power to such components by intelligently transitioning between a normal-operation mode and at least one power-conserving mode. To achieve efficient power conservation, an audio signal detector is provided that generates at least one dispensing event signal that represents the occurrence of one or more sound-based dispensing events. The controller automatically transitions between the power-conserving mode(s) and the normal-operation mode based upon at least one dispensing event data signal supplied to the controller by the audio signal detector, and possibly other data signals supplied to the controller.

Abstract: A displacement control valve includes an electromagnetic solenoid and a drive force transmitting body. A pressure sensing chamber communicates with a suction chamber and a pressure sensing body is located in the pressure sensing chamber. An internal passage is provided in the transmitting body and an external passage is provided about the transmitting body. The first to third valve bodies are provided at the transmitting body. The first valve body adjusts a cross-sectional area of a passage between the external passage and the internal passage. The second valve body adjusts a cross-sectional area of a passage between the internal passage and the pressure sensing chamber. The third valve body adjusts a cross-sectional area of a passage between the external passage and a discharge chamber. The transmitting body is switched among first, second, and third arrangement states by the electromagnetic solenoid.

Abstract: A cryocooler having two operating modes so that its operating range is broadened, its gas bearing system is maintained in an operable state and it can utilize piston stroke modulation for energy efficiency. A piston stroke modulator modulates the piston stroke when the commanded piston stroke exceeds the minimum stroke and maintains the minimum stroke when the commanded stroke is less than the minimum stroke. A heater applies heater power to the thermal load when the commanded piston stroke is less than the minimum piston stroke. A closed loop feedback control system is used which has two branches of its dynamic leg. One branch controls the modulation of the cryocooler and the second, parallel branch controls the modulation of the heater.

Abstract: A thermostat includes a number of control parameters including a temperature set point, a selected cycle rate, a room temperature swing setting, and/or any other suitable control parameter. In one illustrative embodiment, the thermostat includes a push button for providing a signal each time it is depressed and a controller coupled to the push button. The controller is adapted to receive a sequence of one or more signals from the push button, and is further adapted to set a control parameter such as the cycle rate or room swing setting to a value that corresponds to the sequence of one or more signals. In another illustrative embodiment, the thermostat includes a mechanical user interface such as a rotating selector or slider. The thermostat is adapted to receive a signal that relates to the current position of the mechanical user interface, and sets a control parameter of the thermostat based thereon.

Abstract: In a control valve for a variable displacement compressor, for controlling the discharge flow rate of refrigerant to be constant, to dispense with a check valve in a refrigerant outlet port of the compressor. The control valve includes a first control valve that controls the passage cross-sectional area of a refrigerant passage through which refrigerant passes from a discharge chamber of the compressor to a refrigerant outlet port thereof, and a second control valve that controls the flow rate of refrigerant allowed to flow from the discharge chamber to a crankcase such that a differential pressure (Pdh?Pdl) across the first control valve generated by the refrigerant passing therethrough becomes constant. The control valve is configured such that when a solenoid section is not energized, a first valve element is engaged with a piston to forcibly fully open the second control valve.

Abstract: A method of controlling the frequency of a compressor in a chiller system is disclosed. The method includes determining a nominal minimum frequency of a compressor, and providing a control algorithm for controlling the period of time and the deviation of the actual operating frequency below the nominal minimal frequency that the compressor may operate without shutting down the chiller system. The time period of operation below nominal minimum frequency may be predetermined as a fixed time period of operation below nominal minimum frequency, or as a variable time period based on the amount by which the frequency deviates below nominal minimum frequency. Also, an absolute minimum operating frequency is provided that results in the control algorithm shutting down the chiller system and the compressor.

Abstract: The temperature of the air exiting an evaporator and the relative humidity of the air entering and exiting the evaporator can be calculated by using existing sensors in a vapor compression system. The temperature of the air exiting the evaporator is calculated by using the detected temperature of the air entering the evaporator, the saturation temperature of the air, and a bypass factor. The relative humidity of the air entering and exiting the evaporator are then estimated using a psychrometric chart. By using the existing sensors to determine the temperature of the air exiting the evaporator and the relative humidity of the air entering and exiting the evaporator, the load requirement of the vapor compression system can be calculated without employing additional sensors. The system capacity of the vapor compression system can be matched to the load requirement to allow the effective use of electric power.

Abstract: A method for controlling the operation of an air conditioning system, including the steps of operating the air conditioning system until a frequency of a compressor reaches to a preset target frequency, stabilizing the operation of the system after the frequency of the compressor reaches to the preset target frequency, and operating the system at a fixed level.

Abstract: There is provided a cooling apparatus which can improve a cooling efficiency while preventing an abnormal increase in pressure of a high side. The cooling apparatus comprises: a refrigerant circuit which uses carbon dioxide as a refrigerant; a control device which controls a speed of rotation of the compressor between predetermined lowest and highest speeds; and a cooled state sensor which detects a cooled state in a refrigerator main body to be cooled by an evaporator included in the refrigerant circuit. The control device increases a highest speed of rotation of the compressor if a temperature in the chamber of the refrigerator main body detected by the cooled state sensor is low.

Abstract: A vapor compression system includes a main vapor compression circuit having a compressor, a condenser, an expansion device and an evaporator serially connected by main refrigerant lines, the compressor having a suction port, a main discharge port and an intermediate port, and the main refrigerant lines being communicated with the main discharge port and the suction port; a bypass circuit communicated between the intermediate port and the suction portion; and a superheat sensing device positioned to sense superheat in a combined flow from the main vapor compression circuit and the bypass circuit. A method of operation of the system is also provided. The benefits of enhanced system and compressor performance, improved compressor reliability and extended system operating envelope are readily obtained.

Abstract: A vehicular air-conditioner wherein when a detected temperature of an inverter temperature sensor (22g) exceeds a predetermined value, an inverter (6) driving an electric motor (4) of an electric compressor (3) operates in an overheat protection mode for driving the electric motor by a heat protection speed different from the speed command value from the air-conditioning controller (20), secures the refrigerant flow rate, and cools itself. At this time, when a condenser fan (8) or vehicle compartment blower (14) is stopped by passenger operation or air-conditioning control, it is operated to promote the heat exchange at the heat exchangers, whereby it becomes possible to prevent an increase in the refrigerant pressure in the condenser (7) and prevent frost at the evaporator (11) and possible to protect against failure of function of the refrigeration cycle (2).

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.