Abstract: A swash plate compressor including: a housing; a rotating shaft rotatably mounted to the housing; a swash plate accommodated in a crank chamber of the housing and rotating with the rotating shaft; a piston forming a compression chamber with the housing and interlocking with the swash plate to reciprocate; a discharge flow path guiding a refrigerant of the crank chamber to a suction chamber of the housing wherein an inclination angle of the swash plate is adjusted; and a discharge flow path control valve having a valve chamber provided in the discharge flow path and a valve core reciprocating inside the valve chamber, and the valve core includes: a first communication path constantly communicating the discharge flow path; and a second communication path communicating the discharge flow path when differential pressure between pressure of the crank chamber and pressure of the suction chamber is within a certain pressure range.

Abstract: A trailer refrigeration unit is provided. Aspects include a plurality of power sources, wherein the plurality power sources are selectively coupled to a power converter and at least one compressor. The power converter is coupled to at least one fan and is selectively coupled to the at least one compressor. A microcontroller circuit is included and is configured to selectively operate the trailer refrigeration unit in one of a plurality of modes based on an environmental parameter within the trailer refrigeration unit. The plurality of modes includes a first mode where the at least one compressor and at least one fan are powered by the power converter and a second mode where the at least one compressor is powered by at least one of the plurality of power sources.

Abstract: A method for controlling an air conditioner includes, after the air conditioner is turned on, controlling an indoor ambient temperature sensor, an indoor heat exchanger temperature sensor, an outdoor heat exchanger temperature sensor, an outdoor ambient temperature sensor, and an exhaust gas temperature sensor to determine an indoor ambient temperature, an indoor heat exchanger temperature, an outdoor heat exchanger temperature, an outdoor ambient temperature, and an exhaust gas temperature, respectively, determining a first, second, third, fourth, and fifth compressor frequencies based on the indoor ambient temperature, the indoor heat exchanger temperature, the outdoor heat exchanger temperature, the outdoor ambient temperature, and the exhaust gas temperature, respectively, determining a minimum compressor frequency based on the first, second, third, fourth, and fifth compressor frequencies, and controlling a compressor of the air conditioner to operate at the minimum compressor frequency.

Abstract: Provided is a refrigerator system with which refrigerators can be operated efficiently. This refrigerator system has: an upstream refrigerator having a first compressor that compresses a refrigerant, a first condenser that condenses the refrigerant compressed by the first compressor, and a first evaporator that evaporates the refrigerant condensed by the first condenser and cools cold water; a downstream refrigerator having a second compressor that compresses a refrigerant, a second condenser that condenses the refrigerant compressed by the second compressor, and a second evaporator that evaporates the refrigerant condensed by the second condenser and cools the cold water that has passed through the first evaporator; and a higher-level control device that controls the operation of the upstream refrigerator and the downstream refrigerator. The first compressor is a variable-speed device, and the second compressor is a constant-speed device.

Abstract: Disclosed is a method for controlling a refrigerator including a motor driving a compressor. The method for controlling a refrigerator includes: identifying driving revolutions per minute (RPM) for driving of the motor; performing a control of temperature in the refrigerator based on the identified driving RPM; and storing operation information of the motor associated with the performing of the control of temperature, where the identifying of the driving RPM involves identifying stored operation information of the motor associated with a previous motor driving process.

Abstract: A method for controlling torque of an air conditioner compressor is disclosed. In one example, the air conditioner compressor is a variable displacement compressor. The method may provide smooth transitions between different air conditioner compressor torques.

Abstract: A method for operating a cooling circuit. It is provided that a) the actuation signal ST of the coolant compressor is provided so as to increase over time from a minimum value (STmin) in order to generate a start-up phase of the coolant compressor, b) a control signal maximum value (STmax) and a control signal threshold (STSW) are provided, where STSW<STmax, c) the actuation signal (ST) is limited to the control signal maximum value (STmax) if the actuation signal (ST) reaches the control signal threshold (STSW) and the measured high and/or low-pressure value (PHD, PND) satisfies a condition.

Abstract: A refrigeration device includes a cabinet defining a compartment and is operable to control an environment within the compartment. At least one sensor is associated with the compartment. A processor receives compartment data from the at least one sensor associated with the compartment. The processor operates an environmental control system of the refrigeration device according to the compartment data. The processor is communicatively connected to and operates a graphical display of an input module to present compartment data in a graphical user interface of the input module.

Abstract: An outdoor unit of an air conditioner includes a compressor-driving inverter circuit to convert direct current power for driving a compressor into pseudo three-phase alternating current power using a plurality of switching elements; a fan rotational speed detection unit to detect the fan rotational speed of a fan that cools the switching elements; an ambient temperature detection unit to detect the ambient temperature at a location where the air conditioner is located; and a compressor inverter drive unit to control the compressor rotational speed of the compressor by controlling the compressor-driving inverter circuit. The compressor inverter drive unit controls the compressor-driving inverter circuit on the basis of the fan rotational speed and the ambient temperature.

Abstract: A system includes a compressor, an indoor fan, a thermostat, an indoor fan controller, and a compressor controller. The thermostat provides first and second signals based on indoor loading. The fan controller operates the fan in low speed mode and the compressor controller operates the compressor in low capacity mode when only the first signal is asserted. The compressor controller automatically switches the compressor to high capacity mode if only the first signal remains asserted past the low capacity mode runtime. The fan controller operates the fan in high speed mode when the second signal is asserted while the first signal is still asserted. The compressor controller continues to operate the compressor in high capacity mode and the fan controller operates the fan in low speed mode after the second signal is de-asserted, until the first signal is de-asserted, at which point the fan and compressor are turned off.

Abstract: A scroll compressor according to the present invention includes a casing, an orbiting member provided within the casing and performing an orbiting motion, a non-orbiting member forming a compression chamber together with the orbiting member, the compression chamber having a suction chamber, an intermediate pressure chamber and a discharge chamber, a communication passage communicating inside and outside of the compression chamber with each other, an opening/closing valve assembly provided outside the non-orbiting member within the casing and opening and closing the communication passage, and a switching valve assembly provided within the casing and operating the opening/closing valve assembly, whereby a facilitated fabrication, improved valve responsiveness and a relaxed restriction for a specification of a valve can be achieved, and also an over-compression can be prevented by an installation of a check valve, and an assembling efficiency can be improved by installing two valve assemblies outside the non-orb

Abstract: In certain embodiments, a transcritical refrigeration system provides refrigeration by circulating carbon dioxide (CO2) refrigerant through the system. A flash tank of the transcritical refrigeration system is operable to supply the CO2 refrigerant, in liquid form, to a low temperature refrigeration case and a medium temperature refrigeration case. A low temperature compressor is operable to compress the CO2 refrigerant discharged from the low temperature refrigeration case. A medium temperature compressor, a parallel compressor, and an ejector are each operable to compress the CO2 refrigerant discharged from the medium temperature refrigeration case, the CO2 refrigerant discharged from the low temperature compressor, and/or CO2 flash gas discharged from the flash tank. A gas cooler is operable to cool the CO2 refrigerant discharged from the medium temperature compressor and the parallel compressor. A controller is operable to dynamically adjust a pressure set point for the flash tank.

Abstract: An outdoor unit control unit has a defrosting operation condition table that defines an activation rotational speed based on the total sum of the rated capacity of indoor units and a refrigerant pipe length that is the length of a liquid pipe or of a gas pipe. The outdoor unit control unit uses the total sum of the rated capacity of the indoor units and refers to the defrosting operation condition table, so as to determine the activation rotational speed, and then the outdoor unit control unit activates a compressor at the determined activation rotational speed when starting a defrosting operation, maintains this activation rotational speed for a predetermined time (one minute) from the start of the defrosting operation, and drives the compressor.

Abstract: This disclosure relates to a centrifugal compressor. In a first example, the compressor includes a first impeller provided in a main refrigerant flow path, a second impeller provided in the main refrigerant flow path downstream of the first impeller, and a recirculation flow path. In the first example, the recirculation flow path is provided between a first location and a second location along the main refrigerant flow path. The first location is downstream of the second location, and the second location is downstream of the first impeller. In a second example, the compressor includes an impeller provided in a main refrigerant flow path, and a recirculation flow path provided between a first location and a second location along the main refrigerant flow path. In the second example, the recirculation flow path includes a recirculation volute. Further disclosed is a method for operating a centrifugal compressor.

Abstract: In various implementations, an air conditioner may include more than one expansion device. Refrigerant flow through the expansion device(s) may be controlled based at least partially on an operational property of the air conditioner.

Abstract: A system includes a multi-stage cryocooler having multiple stages and a temperature control system configured to regulate temperatures of the multiple stages of the multi-stage cryocooler. The temperature control system includes an input interface configured to receive (i) temperature setpoints for the stages of the multi-stage cryocooler and (ii) temperature information corresponding to temperatures measured at the stages of the multi-stage cryocooler. The temperature control system also includes processing circuitry configured to determine temperature errors and calculate at least one of a compressor stroke error and a pressure-volume phase error. The temperature control system further includes at least one controller configured to adjust at least one of a compressor setting and a pressure-volume phase of the multi-stage cryocooler.

Abstract: The invention relates to a refrigerant circuit (10) of a vehicle air-conditioning system (12), in particular for electric vehicles, comprising a compressor unit (14) which includes a first compressor (16) and a second compressor (18) arranged downstream for compressing a refrigerant (20), a condenser (22) for heating air (24) which can be supplied to a vehicle interior, a first pressure reducing unit (26) arranged downstream of the condenser (22) for decompressing the refrigerant (20) from the condenser (22), a heat exchanger (28) through which refrigerant flows for heat exchange with vehicle ambient air (30), an evaporator (32) for cooling air (24) which can be supplied to a vehicle interior, and a second pressure reducing unit (34) arranged upstream of the evaporator (32) for decompressing the refrigerant (20) from the heat exchanger (28), the second compressor (18), the condenser (22) and the first pressure reducing unit (26) being bypassed in a cooling mode of the vehicle air-conditioning system (12), and

Abstract: Shaft horsepower output associated with a prime mover for driving a component of a transport refrigeration system may be selectively augmented through an auxiliary power apparatus. In an embodiment, a compressed air engine is provided and selectively operable to augment the shaft horsepower output for driving the component. At least one storage tank is provided for storing compressor air and at least one air compressor is provided for generating and supplying compressed air to the at least one compressed air storage tank. In an embodiment, the prime mover is a fuel combustion engine and the compressed air is heated by exhaust gas from the fuel combustion engine. The driven component may be a refrigerant compressor. The driven component may be an electric generator.

Abstract: The present invention relates to an apparatus for controlling a compressor, to a method for controlling a compressor and to a refrigerator comprising same. According to certain embodiments of the present invention, a compressor operates selectively in a TRIAC driving mode or in a mode in which commercial power is directly used in accordance with the quality of the electricity of the commercial power. According to certain embodiments of the present invention, the commercial power is directly applied to the compressor within the range of a predetermined voltage or frequency so as to reduce or remove losses caused by the TRIAC driving, and power consumption is reduced to improve energy efficiency.

Abstract: A refrigerating device is provided which can improve COP when a required load is 50% of a maximum load or below. When the load required of a common evaporator is 50% or less, a control unit stops a second compressor and controls the volume of a first compressor. Accordingly, it becomes possible to improve COP when the required load is equal to or below 50% as compared to the case of controlling the first and second compressors simultaneously to a low volume.

Abstract: A refrigeration vapor compression system including a compressor, an electronic expansion valve with closed loop feedback into a controller, sensors to measure and monitor the system superheat and sub-cooling, and condenser fans controlling the flow of air through the condensing coils, the refrigeration system is operated in at least one of two functional modes to either give priority control to the level of superheat in the system or maintain a minimum level of sub-cooling in the system.

Abstract: A method for use in controlling a free piston Stirling machine having a cold end and a warm end and driven by a linear motor having an armature winding to which a drive voltage is applied. The method comprises (a) sensing internal mechanical collisions; (b) repeatedly sensing the temperature of the cold end, the temperature of the warm end and the drive voltage; (c) storing, as associated data, a value representing drive voltage, the temperature of the cold end and the temperature of the warm end at the time of sensed collisions; and (d) limiting the drive voltage to less than the drive voltage that was sensed at a collision and is stored in association with stored warm end and cold end temperatures that are proximate currently sensed warm end and cold end temperatures.

Abstract: A vehicle air conditioning system includes an electric powered refrigerant compressing device, an evaporator, an electric heater, an air temperature determining component, a cabin interior temperature controlling component, an upper limit electric power setting component, and an electric power distribution controller. The evaporator receives refrigerant from the compressing device. The heater is downstream of the evaporator in an air passageway. The determining component determines a first air temperature upstream of the evaporator and a second air temperature between the evaporator and the heater. The controlling component sets a vehicle interior discharge air temperature at a position downstream of the heater to a target temperature. The power setting component sets an upper limit for power supplied to the compressing device and the heater.

Abstract: An air conditioning system having a cooling mode and a free-cooling mode is provided. The system includes a refrigeration circuit, two pressure sensors, a controller, and a pump-protection sequence resident on the controller. The refrigeration circuit includes a compressor and a pump. The first pressure sensor is at an inlet of the pump, while the second pressure sensor is at an outlet of the pump. The controller selectively operates in the cooling mode by circulating and compressing a refrigerant through the refrigeration circuit via the compressor or operates in the free-cooling mode by circulating the refrigerant through the refrigeration circuit via the pump: The pump-protection sequence turns the pump to an off state based at least upon a differential pressure determined by the controller from pressures detected by the first and second pressure sensors.

Abstract: An air conditioning apparatus includes a refrigerant circuit, an operation controlling device and a liquid refrigerant accumulation determining device. The refrigerant circuit has an accumulator. The operation controlling device performs normal operation control where each device of the heat source unit and the utilization unit are controlled in accordance with operating load of the utilization unit, and refrigerant quantity determination operation control where properness of quantity of the refrigerant in the refrigerant circuit is determined while performing the cooling operation. The liquid refrigerant accumulation determining device determines whether or not liquid refrigerant is accumulating in the accumulator. When it has been determined that liquid refrigerant is accumulating in the accumulator, liquid refrigerant accumulation control is performed to eliminate liquid refrigerant accumulation in the accumulator.

Abstract: Methods, devices and systems capable of performing a hot restart of a compressor driven by a turbine are provided. The turbine has a high speed shaft and a low speed shaft connected to the compressor. A base slow roll speed at which a speed of the low speed shaft is in a slow roll range is maintained at the high speed shaft for a predetermined time. Then, when a vibration amplitude of the compressor is larger than a vibration limit, the maintaining is repeated. Otherwise, a set speed of the high speed shaft is increased, until a current speed of the low speed shaft reaches a minimum operating speed. If, while increasing the set speed, the vibration amplitude becomes larger than the vibration limit, the maintaining is repeated.

Abstract: A refrigerating apparatus includes first and second refrigerant circuits including respective first and second compressors, condensers, pressure reducers, and evaporators, connected circularly with first and second refrigerant pipes, respectively, refrigerants discharged from the first and second compressors being respectively condensed at the first and second condensers and thereafter respectively evaporated at the first and second evaporators to acquire a cooling effect; a temperature sensor that detects a temperature of an internal portion of a cold storage cabinet, the first and second evaporators being disposed to cool the internal portion simultaneously; and a first control device that controls the first and second compressors such that the first compressor and the second compressor start being alternately operated each time a temperature detected by the temperature sensor reaches a first temperature, and are continuously operated until the detected temperature reaches a second temperature lower than th

Abstract: A method is disclosed for controlling a discharge pressure of a compressor relative to a suction pressure of the compressor. The discharge pressure and suction pressure of the compressor are monitored and compared with a predetermined maximum pressure ratio of discharge pressure to suction pressure. If the pressure ratio of discharge pressure to suction pressure exceeds a predetermined pressure ratio limit less than the maximum pressure ratio, a controller unloads the compressor. The predetermined pressure ratio limit is determined relative to the measured suction pressure. The discharge pressure and suction pressure are further monitored and the compressor is inhibited from being reloaded for a predetermined time delay. After the predetermined time delay has elapsed, the compressor is reloaded only if i) the discharge pressure falls below a predetermined reload pressure and ii) the chiller system requires additional cooling capacity.

Abstract: This disclosure relates to a centrifugal compressor. In a first example, the compressor includes a first impeller provided in a main refrigerant flow path, a second impeller provided in the main refrigerant flow path downstream of the first impeller, and a recirculation flow path. In the first example, the recirculation flow path is provided between a first location and a second location along the main refrigerant flow path. The first location is downstream of the second location, and the second location is downstream of the first impeller. In a second example, the compressor includes an impeller provided in a main refrigerant flow path, and a recirculation flow path provided between a first location and a second location along the main refrigerant flow path. In the second example, the recirculation flow path includes a recirculation volute. Further disclosed is a method for operating a centrifugal compressor.

Abstract: A refrigerator is provided having a refrigeration system including a variable speed compressor, a condenser, a condenser fan, an evaporator, a variable speed evaporator fan. The refrigerator further includes multiple temperature sensors that communicate with an electronic microprocessor-based control system that in turn controls the operation of the refrigerator system based on the information provided by the multiple temperature sensors.

Abstract: A variable displacement compressor with a compensated suction shutoff valve (SSV). The SSV prevents noise generated by a suction reed valve at low refrigerant flow rates in an internal suction region from propagating to an air conditioner evaporator by moving a piston to obstruct an opening and restrict fluid communication. The degree of restriction is decreased by an opening force generated by refrigerant at an external suction pressure acting over a first area, and increased by refrigerant at a crankcase pressure acting over a second area. The second area is smaller than the first area so that at high refrigerant flow rates, the effect of crankcase pressure is reduced so that the restriction is reduced and the compressor operates at greater efficiency. The piston position is also influenced by refrigerant at a pressure intermediate the external suction pressure and the internal suction pressure acting over a third area.

Abstract: Techniques herein describe a pumping system, adapted to reduce or eliminate fluid cavitation. Optionally, the pumping system is adapted for application to a passive fluid recovery system. In one example, the pumping system includes a pump and a thermal sub-cooling device. The thermal sub-cooling device may sub-cool fluid input to a pump and heat fluid output from the pump, particularly under start-up conditions. In a further example, a controller manages power supplied to both the pump and the thermal sub-cooling device, to transition from an ambient temperature start-up condition to an elevated temperature operating condition.

Abstract: A system and method is provided to control and operate a compressor to have two or more discrete output capacities in response to an outdoor temperature measurement. During operation of the compressor in an air conditioning or cooling mode, the compressor has a first output capacity in response to the outdoor temperature being greater than a first temperature setpoint and the compressor has a second output capacity in response to the outdoor temperature being less than a second temperature setpoint. During operation of the compressor in a heating mode, the compressor has different output capacities based on the outdoor ambient temperature.

Abstract: A no-frost refrigerator includes at least one storage compartment, an evaporator, which can be switched on and off and is disposed in a chamber that is separate from the storage compartment, and a fan for driving an exchange of air between the storage compartment and the chamber. Of the evaporator and fan, at least one can be operated while the other is switched off.

Abstract: A system for controlling a centrifugal gas compressor (108) in an HVAC, refrigeration or liquid chiller system (100) in which flow of gas through the compressor is automatically controlled to maintain desired parameters within predetermined ranges so as to prevent stall and surge conditions within the system. A variable geometry diffuser (119) in the compressor controls the refrigerant gas flow at the discharge of the compressor impeller wheel (201). This arrangement reduces mass flow, decrease/eliminate flow-reducing stall, and increases the operating efficiency of the compressor at partial load conditions. The variable geometry diffuser control in combination with a variable speed drive (VSD) (120) increases the efficiency of the compressor at partial system loads, and eliminates the need for pre-rotation vanes at the inlet of the centrifugal compressor.

Abstract: A refrigerating apparatus includes first and second refrigerant circuits including respective first and second compressors, condensers, pressure reducers, and evaporators, connected circularly with first and second refrigerant pipes, respectively, refrigerants discharged from the first and second compressors being respectively condensed at the first and second condensers and thereafter respectively evaporated at the first and second evaporators to acquire a cooling effect; a temperature sensor that detects a temperature of an internal portion of a cold storage cabinet, the first and second evaporators being disposed to cool the internal portion simultaneously; and a first control device that controls the first and second compressors such that both of them are operated each time a temperature detected by the temperature sensor reaches a first temperature, and the first and second compressors are alternately operated each time a temperature detected by the temperature sensor reaches a second temperature lower t

Abstract: A management system for vehicle air-conditioning and a method of managing the same are provided. Changes of a temperature in a vehicle from various environmental information, between a standard for showing a comfortable environment in the vehicle and actual environment information, are recognized to identify abnormalities occurring in components at an early stage and to appropriately judge the necessity and urgency of maintenance. A management system of vehicle air-conditioning includes an air-conditioning controller that predicts abnormalities of components of the refrigeration cycle by comparing a temperature in the vehicle obtained when the refrigeration cycle is actually driven with a preset temperature in the vehicle that constitutes a standard.

Abstract: A system and method for a compressor may include an inverter drive connected to the compressor that receives electric power and modulates a speed of the compressor by modulating a frequency of the electric power. A control module connected to the inverter drive monitors compressor power data and compressor speed data from the inverter drive, and calculates a saturated condenser temperature of a refrigeration system associated with the compressor based on the compressor power data and the compressor speed data.

Abstract: A compressor drive torque estimating device to be adapted for a system provided with a refrigeration cycle in which a refrigerant is circulated by a compressor driven by a drive source mounted in a vehicle, comprising heat load detecting means for detecting a heat load of the refrigeration cycle, a storage unit storing a plurality of estimated drive torque characteristics establishing correlation between a drive torque change characteristic of the compressor and an elapsed time from a time of start of operation of the compressor, an estimated drive torque characteristic selecting means for selecting the one of the plurality of estimated drive torque characteristics stored in the storage unit based on detected values detected by the heat load detecting means, and an estimated drive torque calculating means for calculating an estimated drive torque of the compressor based on the estimated drive torque characteristic selected by the estimated drive torque characteristic selecting means.

Abstract: A compressor inlet pressure estimation apparatus for a refrigeration cycle system is disclosed. An electronic control unit 14 answers YES by judging that the command to start a compressor 2 is issued when an air-conditioning switch is turned on in step S100. After that, the electronic control unit 14 answers NO in the case where a timer count time Tc is shorter than a predetermined time T1 in step S120. At the same time, Tefin_C is set to 15° C. in step S130. The lower one of Tefin_C and Tefin determined in this way is determined as Tefin_d (step S150). After that, Tefin_d is input to the first-order lag function to acquire Tefin_AD(N). Then, the control proceeds to step S170, where the estimated value Ps_es(N) of the refrigerant inlet pressure of the compressor 2 is determined using Tefin_AD(N) and Gr.

Abstract: Vehicle cooling fan control system and method which prevent an occupant from hearing peculiar sounds from a cooling fan due to a decrease in rotation speed are provided. The vehicle cooling fan control system according to the present invention is configured not to stop the rotation of a fan motor for a predetermined time even upon satisfaction of an air conditioner stoppage condition as long as a vehicle interior is quiet.

Abstract: A refrigeration device includes a switching valve control section for outputting a switching signal for controlling a four-way switching valve to a predetermined switching state when starting a compression mechanism; and a switching determination section which, when starting only a first compressor as a start-up of the compression mechanism, outputs a low differential pressure signal if a differential pressure between a high-pressure port and a low-pressure port in the four-way switching valve falls below a determination value in a determination operation after the switching signal being outputted by the switching valve control section. After the switching determination section outputs the low differential pressure signal, a capacity control section starts a second compressor.

Abstract: A capacity control system for a variable capacity compressor includes target suction pressure setting means for setting, based on external information input from external information detection means, a target suction pressure for controlling the pressure in a suction pressure region as a control target, suction pressure estimation means for estimating, based on the external information, a pressure that is estimated to prevail in the suction pressure region if the variable capacity compressor is operated with a maximum discharge capacity, and discharge capacity determination means for determining, based on the suction pressure estimated by the suction pressure estimation means and the target suction pressure set by the target suction pressure setting means, whether the variable capacity compressor is operating with the maximum discharge capacity or with a controlled discharge capacity.

Abstract: A refrigerant system is provided that includes a compressor, a motor for driving the compressor, a refrigerant system component, and a controller. The refrigerant system component can operate in a pulse width modulated mode having a loaded phase and an unloaded phase. The compressor motor is loaded in the loaded phase but unloaded in the unloaded phase. The controller applies a first voltage to the compressor motor in the loaded phase and a second voltage to the compressor motor in the unloaded phase. Here, the second voltage is less than the first voltage.

Abstract: In a refrigerating cycle apparatus and control method thereof, a controller sets a high-pressure pressure target value from thermal load and temperature conditions based on refrigerant information that has been obtained from detectors, and controls at least one of a rotational frequency of a compressor, a degree of opening of an electronic expansion valve, a rotational frequency of an outdoor fan, or a rotational frequency of an indoor fan to match a high-pressure pressure to the high-pressure pressure target value that has been set. Here, a threshold value is set when the high-pressure pressure target value is set, and a method for setting the high-pressure pressure target value is modified depending on whether the high-pressure pressure is greater than or equal to the threshold value or less than the threshold value when the high-pressure pressure target value is decided.

Abstract: An improved method for sequencing variable speed centrifugal compressors on and off line to ensure optimal operating efficiency in a liquid cooling system under all operating circumstances is described. The present disclosure teaches modifying equipment sequencing decisions (to add or shed a unit), based in part on the position of the compressor inlet vanes. This new approach achieves improved energy efficiency of the overall system by taking into account operating conditions of individual compressors or chillers that may be sub-optimal.

Abstract: A reciprocating compressor includes a first cylinder and a second cylinder, first and second suction cutoff unloader valve assemblies, and a controller. The first and second suction cutoff unloader valve assemblies are integral to the compressor and are capable of a rapid cycling to interrupt flow of refrigerant to the first and second cylinders. The controller operates at least one of the first suction cutoff unloader valve assembly or second suction cut-off unloader valve assembly in the rapid cycling and monitor a number of rapid cycles. In another aspect, a multi-stage compressor comprises a lower pressure stage and a higher pressure stage, and at least one suction cutoff unloader valve assembly capable of a rapid cycling to interrupt flow of refrigerant to a lower stage cylinder.

Abstract: An electropneumatic control arrangement for an automatic vehicle level control system, particularly of a commercial vehicle, includes at least; a solenoid valve unit having at least two electropneumatic solenoid valves, a compressed air inlet for infeeding compressed air, at least one compressed air connection for at least one air bellows and electrical control inputs, and an electronic control unit for actuating the solenoid valve unit. The electronic control unit comprises control outputs for electrically connecting to the control inputs of the solenoid valve unit. A plug connector is configured on the housing of the solenoid valve unit, in which the electrical control inputs are disposed, and a plug connector is provided on the housing of the electronic control unit, in which the control outputs are disposed. The plug connectors are mechanically plugged into each other.

Abstract: A structure for sensing refrigerant flow rate in a compressor. The structure includes a passage forming member, a restriction hole, a differential pressure-type flow rate sensor, and a partition plate. The compressor includes a housing connected to an external refrigerant circuit via a refrigerant passage. The passage forming member is connected to an outer surface of the housing and forms a part of the refrigerant passage. The restriction hole divides the refrigerant passage into an upstream passage and a downstream passage. The upstream passage is formed in either the housing or the passage forming member. The sensor is provided in the passage forming member and detects pressure in the upstream passage and pressure in the downstream passage to sense flow rate of refrigerant in the refrigerant passage. The partition plate is disposed between the housing and the passage forming member. The restriction hole is formed in the partition plate to extend through the partition plate.

Abstract: In a refrigeration cycle device in which a compressor is driven by power transmitted from an engine, a torque limiter is adapted to interrupt a transmission of the power from the engine to the compressor when a torque transmitted from the engine to the compressor becomes a predetermined value. A control unit is adapted to determine whether the transmission of the power from the engine to the compressor is interrupted by the torque limiter by determining whether a deviation of a refrigerant discharge pressure of the compressor is below a predetermined pressure when the control unit commands the compressor to change the refrigerant discharge flow amount of the compressor. Thus, the control unit can determine whether the torque limiter interrupts the transmission of power from the engine to the compressor without, using a compressor revolution sensor.