Abstract: There is provided a refrigeration apparatus in which a refrigerant accumulating in non-operating outdoor units is supplied to an outdoor unit being operated in which a shortage of refrigerant occurs without starting the compressors of the non-operating outdoor units.

Abstract: A system and a method for operating a variable-displacement compressor are provided wherein a volume of a compression chamber of at least one cylinder is varied during a compression cycle, wherein during the cycle the at least one cylinder is alternately coupled to a low pressure side and a high pressure side of the compressor. A first thermodynamic state of the low pressure side and a second thermodynamic state of the high pressure side can be estimated and a current compression ratio ( v in v out ) of the compressor can be estimated. Accordingly, a compressor displacement (D) as a function of the compression ratio ( v in v out ) can be calculated. From this, a compressor torque (M) depending on the calculated displacement (D) can be computed, and the compressor torque (M) can be provided to a control unit for operating the compressor or an engine coupled to the compressor.

Abstract: A refrigerant compressor assembly for a refrigeration circuit controls the temperature within a temperature controlled space. The refrigerant compressor assembly includes a first unloading valve, a first valve actuator, and a first valve control system that adjusts the first valve actuator via a pulse-width-modulated signal, a second unloading valve, a second valve actuator, and a second valve control system that adjusts the second valve actuator via a pulse-width-modulated signal. The refrigerant compressor assembly also includes a third unloading valve. The first valve actuator is coupled to the first and third unloading valves and controlled by the first valve control system. The unloading valves selectively allow or resist fluid flow from higher to lower pressure areas within the refrigerant compressor assembly.

Abstract: A refrigerant system includes a compressor that has safe operating limits that are also built into a refrigerant system control to protect the compressor. Under certain conditions, these safe operational limits may be changed to allow the compressor to operate beyond the safety limits at least for a period of time.

Abstract: A pulse width modulation control is provided for a suction modulation valve in a refrigerant system. An intentional small “leakage” path is maintained through the suction modulation valve to ensure that the pressure inside the compressor shell does not decrease below a safe reliability threshold but, at the same time, does not exceed a certain value, which would cause the refrigerant system to operate inefficiently, when the pulse width modulation control has moved the suction modulation valve to a closed position. The size of this minimum “leakage” path is continuously adjusted to ensure that the optimum pressure inside the compressor shell is maintained regardless of the evaporator pressure and other operating conditions.

Abstract: To provide a refrigerating apparatus that can control the supercooling degree of liquid refrigerant irrespective of changes in circulating refrigerant amounts in a refrigeration cycle, a refrigerating apparatus includes a refrigeration cycle having one or more compressors or inverter compressor, a condenser, an expansion valve, and an evaporator; a liquid introduction circuit that guides decompressed refrigerant obtained by extracting one part of high pressure liquid refrigerant from the refrigeration cycle and decompressing, to a supercooling heat exchanger provided in the refrigeration cycle to perform heat transfer between the decompressed refrigerant and high pressure liquid refrigerant, and then introduces the refrigerant into refrigerant for intake into the compressors or inverter compressor or an intermediate pressure part of these compressors; a controller controlling shutdown of the compressors or driving frequencies of the inverter compressor based on suction pressure detection values with respect t

Abstract: A compressor drive torque estimating device suppresses a discrepancy between an estimated drive torque, which is based on a torque estimating device of a compressor, and an actual drive torque of the compressor. The discrepancy is due to delay in switching between employment of the torque estimating device and the actual drive torque of the compressor in judging the compressor torque. Thus, even in a transitional state immediately after the start of compression, the idling speed of an engine driving the compressor is controlled based on an accurate estimate of the compressor torque, to improve the stability of the engine idle speed.

Abstract: A compressor controlling apparatus including a bypass unit connected between an outlet and an inlet of the compressor and a control unit. The control unit reduces pressure difference between the outlet and the inlet of the compressor by the bypass unit to start the compressor when the compressor is to be started. The compressor is started while pressure equilibrium is achieved by the bypass unit, thereby preventing poor start-up of the compressor caused due to excessive pressure difference, and thus improving reliability of the compressor.

Abstract: The compressor has a differential pressure type flow rate detector that obtains the pressure in an upstream passage and the pressure in a downstream passage to detect a refrigerant flow rate within a refrigerant passage. The detector has an accommodation chamber, and a partition body slidably accommodated within the accommodation chamber. The partition body comparts the accommodation chamber into a high pressure chamber to which the pressure in the upstream passage is introduced, and a low pressure chamber to which the pressure in the downstream passage is introduced. The compressor has an oil separator having an oil introduction passage connected to the oil separating chamber and a high pressure introduction passage introducing the pressure in the upstream passage to the high pressure chamber. The oil introduction passage introduces the oil separated from the refrigerant by the oil separator to a pressure zone other than a discharge pressure zone.

Abstract: An integrated cooling system includes two separate evaporator coils. Each evaporator coil has its own shutoff, thereby allowing for individual control over the cooling of each of two vehicle spaces. The evaporator coils may be disposed within the vehicle to cool the passenger compartment and a battery compartment, respectively. The separate control afforded by the cooling system provides the flexibility of shutting off cooling to the vehicle passenger compartment for the comfort of the vehicle occupants, while still providing cooling to the battery, as needed. The cooling system includes a number of control features which provide for automatically shutting off cooling to one or more of the evaporator coils based on parameters such as air temperature and refrigerant pressure.

Abstract: The present invention involves a compression refrigeration system including a compressor, a heat rejector, expansion means and a heat absorber connected in a closed circulation circuit that may operate with supercritical high-side pressure. An apparatus and method are provided to optimize energy efficiency.

Abstract: A refrigeration system including a refrigeration circuit and a controller. The refrigeration circuit includes a plurality of variable capacity compressors arranged in parallel to compress a refrigerant. A second variable capacity compressor is started after a first variable capacity compressor. An evaporator defines a load while evaporating the refrigerant to refrigerate a space within a predetermined temperature range. The controller is programmed to control the operation of the plurality of variable capacity compressors to match the capacity of the plurality of variable capacity compressors to the load by increasing the capacity of the last compressor in the queue of running compressors when the capacity of the plurality of variable capacity compressors is lower than the load and by decreasing the capacity of the first compressor in the queue when the capacity of the plurality of variable capacity compressors is higher than the load.

Abstract: A dynamic system controls indoor relative humidity and temperature to achieve specified conditions by applying multiple stages of dehumidification. In addition to a stage that increases dehumidification by reducing the speed of the indoor blower, the system uses a reheat coil and multiple valves that allow the reheat coil to function as either a subcooling coil or a partial condenser. Thus the system can maintain specified indoor temperature and humidity conditions even at times when no heating or cooling is needed. The system may have an outdoor condensing unit including a compressor and a condenser operably connected via refrigerant lines to an indoor unit to form a “split system” refrigerant loop.

Abstract: A refrigeration cycle apparatus includes a compressor, a condenser, a pressure-reducing mechanism, an evaporator, an orifice provided in a refrigerant flow path from the compressor to the pressure-reducing mechanism, a differential pressure sensor that detects the differential pressure before and after the orifice, a refrigerant flowrate calculating portion that calculates a refrigerant flowrate based on the differential pressure, and a torque estimating portion that estimates the torque required to drive the compressor based on the refrigerant flowrate calculated by the refrigerant flowrate calculating portion, the intake pressure of the compressor, and the discharge pressure of the compressor.

Abstract: A vehicle air conditioner is controlled to a target control value that controls a swash-plate control value of a swash-plate variable capacity compressor. The variable control is based on temperature deviation between target evaporator temperature and actual evaporator temperature, to control compressor discharge capacity. A target evaporator temperature is set. Deviation between the target evaporator temperature and actual evaporator temperature is calculated. Control coefficients are variably set according to the magnitude of the temperature deviation. A target control value of a pressure control valve of the swash-plate variable capacity compressor is calculated using the control coefficients. The pressure control valve is controlled by the target control value.

Abstract: A controller reduces a rotational speed of a Rankine cycle from a predetermined normal rotational speed during an operation of a compressor in a predetermined state when the controller determines that a predicted refrigerant flow quantity, which is predicted by assuming that the compressor is operated in a sole operation of the Rankine cycle at the predetermined normal rotational speed of the Rankine cycle, exceeds a predetermined flow quantity. The predetermined state is a state that satisfies a predetermined condition, which relates to the sole operation of the Rankine cycle.

Abstract: A displacement control mechanism for a variable displacement compressor includes a first valve hole, a first valve body, a pressure sensing means operable to sense pressures of first and second points in a discharge pressure region to adjust a position of the first valve body, and a pressure-difference-increasing means operable to increase pressure difference between the first and second points when the pressure of a suction pressure region falls below a predetermined standard pressure. The pressure sensing means displaces the first valve body to increase an opening degree of the first valve hole according to increase of the pressure difference when the first valve hole is part of a supply passage. The pressure sensing means displaces the first valve body to decrease the opening degree of the first valve hole according to the increase of the pressure difference when the first valve hole is part of a bleed passage.

Abstract: An inverter (22) is provided between a power source (20) and a suction/discharge valve driving motor (14) that controls cycle time of suction and discharge of a refrigerator unit (10). An output frequency of the inverter (22) is controlled in accordance with output of a sensor (24) that detects temperature of a thermal load portion (11) of the refrigerator unit (10). This enables temperature adjustment of individual refrigerators with a highly reliable method without using an electric heater.

Abstract: A HVAC system for a vehicle that includes a propulsion system, a frame, a passenger compartment, and a door coupled to the frame. The HVAC system includes a refrigeration circuit that selectively controls the temperature of the passenger compartment based on a sensed temperature within the passenger compartment. The refrigeration circuit includes an exterior heat exchanger, a first air moving device coupled to the exterior heat exchanger, an interior heat exchanger, a second air moving device coupled to the interior heat exchanger, and a compressor. The HVAC system also includes a controller that is operable to detect a condition of the vehicle that includes at least one of a position of the door, a location of the vehicle, and a load of the propulsion system. The controller is programmed to adjust the refrigeration circuit in response to the sensed passenger compartment temperature and the detected vehicle condition.

Abstract: When a guard timer of a compressor (141) expires, an R2 signal from a control section (140) of an outdoor unit is turned on (Action I). If a control section (120) of a freezer unit recognizes from an inside temperature detected by a temperature sensor (124) that the R2 signal is turned on and a request for a shift to a freezer thermo-on state is raised (Action II), a freezer electromagnetic valve (121) is opened (Action III). In general, when the electromagnetic valve (121) is opened, it is supposed that an increase in refrigerant suction pressure is detected by a pressure sensor (146) and then the compressor (141) is actuated. However, if an outside air temperature is low, the refrigerant suction pressure remains lower than a predetermined value. Therefore, the control section (120) actuates a booster compressor (131) (Action IV) to raise the refrigerant suction pressure of the compressor (141).

Abstract: A displacing device is incorporated in a displacement control valve. The displacing device includes a first pressure chamber, a second pressure chamber, a second bellows, a transmission rod, and an urging spring. The second pressure chamber communicates with a suction chamber. The interior of the second pressure chamber is a suction pressure zone. When the pressure in the suction pressure zone is less than or equal to a predetermined reference pressure, the transmission rod moves an actuation rod (valve body) to open a valve hole. Therefore, a variable displacement compressor is prevented from operating with a large displacement when there is insufficient amount of refrigerant or when the speed of the compressor is high.

Abstract: Trace gas leak detectors and methods for trace gas leak detection of large leaks at relatively high test pressures are provided. A trace gas leak detector includes a test port to receive a sample containing a trace gas, the test port connected to a test line, a mass spectrometer to detect the trace gas, a high vacuum pump having an inlet port coupled to the inlet of the mass spectrometer, and a forepump having a main inlet, at least one intermediate inlet and an exhaust. The main inlet of the forepump is coupled to the exhaust port of the high vacuum pump. The intermediate inlet is controllably connected to the test line. The forepump is selected from the group consisting of a scroll vacuum pump and a screw vacuum pump.

Abstract: A coil of an electric motor is cooled by refrigerant. A controller for the electric motor controls a current supplied to the coil within a range less than or equal to a predetermined maximum value. A temperature detection section detects either a temperature of the coil or a temperature about the coil. When a detection temperature that is detected by the temperature detection section prior to activation of the electric motor reaches a predetermined reference temperature, a limiting section executes a limiting control to limit an upper limit value of the current supplied to the coil to a limiting value that is less than the maximum value. Accordingly, the coil of the electric motor is protected without stopping the operation of the electric compressor immediately after activation.

Abstract: An error in judgment due to the difference in the temperature of the refrigerant at an outlet of a condenser is reduced when judging the adequacy of the refrigerant quantity. An air conditioner (1) includes a refrigerant circuit (10), operation controlling means, and refrigerant quantity judging means. The refrigerant circuit (10) is configured by the interconnection of a compressor (21), an outdoor heat exchanger (23), a subcooler (25), an indoor expansion valve (41, 51), and an indoor heat exchanger (42, 52). The operation controlling means can perform a refrigerant quantity judging operation in which performance of the subcooler (25) is controlled such that the temperature of the refrigerant sent from the subcooler (25) to the indoor expansion valve (41, 51) becomes constant.

Abstract: A refrigerating machine includes a compressor for compressing a refrigerant, a radiator for radiating heat from the refrigerant discharged from the compressor, an expander for expanding the refrigerant discharged from the radiator, and an evaporators for evaporating the refrigerant discharged from the expanders, all connected in series. The refrigerating machine also includes a refrigerant flow regulator for regulating the amount of refrigerant flowing into the expander and a controller for controlling the compressor and the refrigerant flow regulator. At a stop of the compressor, the controller controls the refrigerant flow regulator to reduce the amount of refrigerant flowing into the expander.

Abstract: A refrigeration system includes a two-stage linear compressor having a first piston disposed in a first cylinder and a second piston disposed in a second cylinder. The linear compressor is operable in an economizer cycle wherein the first piston operates as a first stage of the economizer cycle and the second piston operates as a second stage of the economizer cycle. A controller is coupled to the linear compressor to control a volume flow ratio of the linear compressor. The controller stores a plurality of coefficients of performance for a range of particular operating conditions of the linear compressor and each coefficient of performance corresponds to a desired volume flow ratio and a desired secondary evaporating temperature.

Abstract: The present invention relates to a method and apparatus for effectively reducing/eliminating shut-downs while still allowing an air or gas dryer apparatus to operate even though the conditions, even extreme conditions, may be out of range. The present invention comprises a system and apparatus controlling a variable speed compressor system for an air or gas dryer, the system and apparatus comprising a set point value that causes system shut down when reached and an algorithm that operates using the set point value. A sensor that provides an input value to the algorithm whereupon the algorithm compares the input value to the set point value, a circuit carrying output of the algorithm, a controlled device responding to the output and a feedback circuit that operates to maintain a product value at a set point or within a set range where the algorithm operating to modulate or bypass the feedback circuit when the input value approaches the set point.

Abstract: Disclosed is a method for controlling an air conditioner. In particular, driving modes of elements, namely sucking/discharge compressure, of the compressor in operation are determined so that variable means are controlled to ensure for the elements of the compressor to be within predetermined value ranges in safe area. According to the present invention, vibrations/noises that usually occur when the compressor is in unstable area are greatly reduced and thus, the compressor can be protected from damages.

Abstract: A control device for an air conditioning device including a variable capacity compressor which has a variable capacity actuator, includes a full stroke control setting value computation module which is configured such that, when a capacity control output value output to the variable capacity actuator is increased greater than a full stroke value which results the variable capacity compressor reaching a full stroke, and when a differential pressure that is proportional to the capacity control output value is verified to be no longer maintained, backtracks to a point of time when a differential pressure maintenance function of the variable capacity compressor is lost, and computes a full stroke control setting value of the variable capacity compressor that a discharge capacity of the variable capacity compressor is saturated, based on the capacity control output value obtained at the point of time when the differential pressure maintenance function of the variable capacity compressor is lost.

Abstract: A linear compressor control system includes an electronic circuit controlling an electric motor that drive a piston of the compressor, such that the motor is operated intermittently with an on-time (tL) and an off-time (tD) to keep the compression capacity of the compressor substantially constant. The compressor is associated with a closed cooling circuit having an evaporator and a condenser. The off-time (tD) is shorter than the time necessary for the evaporation pressure (PE) in the evaporator and the condensation pressure (Pc) in the condenser to equalize each other after the compressor has been turned off.

Abstract: To improve the pressure resistance strength of a pressure-sensing section of a control valve for a internal variable control compressor. In the control valve, a stack of snap-acting discs is disposed on a side of a diaphragm forming the pressure-sensing section opposite from a transmitting member. With this arrangement, even if the diaphragm receives large suction pressure Ps, since the snap-acting disc receives suction pressure Ps from the opposite side, the diaphragm is prevented from being broken or deformed. This makes it possible to improve the pressure resistance strength of the pressure-sensing section. As a result, even if the control valve is applied to a refrigeration cycle in which suction pressure Ps becomes high, such as one using carbon dioxide as refrigerant, it is possible to secure sufficient pressure resistance strength.

Abstract: The embodiments described herein include a control system and method for a compressor that is operable with a climate system. The control system enables optimal climate system operation by efficiently controlling the operating speed of the compressor.

Abstract: A compressor inlet pressure estimation apparatus for a refrigeration cycle system is disclosed. An electronic control unit 14 uses Tefin_lag(N) as an actual corrected temperature Tefin_AD(N) during a period Tp1 included in the timing t1 to t2. During a period Tp2 included in the timing t1 to t2, Tefin_fwd(N) is used as the actual corrected temperature Tefin_AD(N). Thus, a highly accurate corrected temperature Tefin_AD(N) can be determined over the on period (t1 to t2) of a compressor 2. In addition, Tefin_fwd(N) is used as the actual corrected temperature Tefin_AD(N) during the off period (t2 to 3) of the compressor 2. As a result, a highly accurate corrected temperature Tefin_AD(N) can be determined over the whole period including the on and off periods of the compressor 2. In this way, a highly accurate estimated value Ps_es(N) of the refrigerant inlet pressure of the compressor 2 can be determined.

Abstract: A refrigerant compressor has a control valve for controlling the degree of conveyance of the refrigerant compressor by setting a drive housing pressure pC of the refrigerant compressor. A control body controls a conveying-side control line between a discharge chamber, acted upon by high pressure of the compressor, and the drive housing of the compressor, and also controls a suction-side control line between the drive housing and a suction chamber, acted upon by suction pressure of the compressor variably in a throttling and/or shutting-off manner. The control body is driven electromagnetically. To improve the refrigerating capacity and the control behavior of the refrigerating system, the control body, which can shut off both the conveying-side and the suction-side control line, is also driven by means of a pressure cell.

Abstract: A system and method including a compressor operable in a refrigeration circuit and including a motor, a current sensor detecting current drawn by the motor and providing a high-side condition signal, a discharge line temperature sensor detecting a discharge line temperature of the compressor and providing a low-side condition signal, and processing circuitry processing the high-side condition signal and the low-side condition signal during installation of the compressor to initially configure the compressor based on a non-measured condition of the refrigeration circuit.

Abstract: An air conditioning system comprises a compressor 2 which compresses a refrigerant made of carbon dioxide, a radiator 4 which radiates heat of the refrigerant compressed by the compressor 2, an expansion valve 5 which decompresses the refrigerant which dissipated heat by the radiator 4 and which can control a refrigerant pressure on the outlet side of the radiator 4, an evaporator 7 which evaporates the refrigerant decompressed by the expansion valve 5, a sensor 13 which detects temperatures of a surface of a pipe through which a high pressure refrigerant on the outlet side of the radiator passes, and a control apparatus 23 which calculates a target refrigerant pressure on the outlet side of the radiator 4 based on a value detected by the sensor to control the expansion valve 5. The control apparatus corrects the target refrigerant pressure on the outlet side of the radiator 4 corresponding to refrigerant temperatures.

Abstract: Implementations of the present invention include systems, methods, and apparatus for improving the fuel efficiency (mpg/kpl) of a motor vehicle during those times when the vehicle air conditioning system is operating. Whenever the driver takes his foot off the gas, or the vehicle engine is otherwise caused to decelerate, the refrigerant compressor clutch engages, allowing the compressor to operate on previously-imparted vehicle waste energy (e.g., imparted by the engine, or by downhill travel.) When the refrigerant pressure reaches a pre-set maximum value, the clutch is deactivated, and the compressor stops. When the refrigerant pressure reaches a pre-set minimum level, the clutch is activated regardless of the existence of vehicle waste energy. When the refrigerant pressure reaches another pre-set level between the aforementioned maximum and minimum levels, in the absence of any vehicle waste energy, the clutch is again deactivated and the compressor stops.

Abstract: The present invention concerns a method for improving the efficiency of a transcritical cooling installation and the installation itself.

Abstract: A method for controlling a refrigeration system comprising a variable compressor capacity, and at least two refrigeration entities, e.g. display cases. Suction pressure is controlled by means of permitting/preventing a flow of refrigerant into evaporator of one or more refrigeration entities. Compressor capacity is controlled to match a desired capacity level and based on a signal derived from one or more properties of the one or more refrigeration entities, said signal reflecting a possible difference between the current compressor capacity and a current refrigeration demand of the refrigeration system. Reduces wear on compressors because switching them ON/OFF is avoided to the largest extent possible. Prevents problems relating to conflicting control strategies due to control parameters, e.g. suction pressure, being controlled by means of two or more controllable parts, e.g. compressors and flow of refrigerant into refrigeration entities.

Abstract: To provide a control valve for a variable displacement compressor, which is capable of stably operating in a pressure control area, and causing the compressor to quickly shift to operation with the minimum displacement. The control valve for a variable displacement compressor is capable of realizing stable pressure control, since a force applied to a valve element in a valve-closing direction increases when the valve element is in a pressure control area, and is balanced with a force applied to the valve element in a valve-opening direction by the pressure of refrigerant. Further, when the valve element moves past an end point of the pressure control area, the force applied to the valve element in the valve-closing direction decreases to thereby increase the valve-opening degree of a valve portion when the valve portion is fully open.

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: A compressor for a turbo chiller that can stably and efficiently operate in various operating states is provided. An aerodynamic feature map showing a rotating stall line at which rotating stall occurs is provided on a map represented by a flow parameter reflecting the volume flow based on the output thermal capacity of the chiller and by a pressure parameter reflecting the head based on the evaporator pressure and the condenser pressure. A minimum rotation speed obtaining unit obtains a minimum rotation speed from the pressure parameter and the rotating stall line on the aerodynamic feature map in the current operating state, and a rotation speed greater than or equal to the minimum rotation speed thus obtained is designated to the inverter.

Abstract: Controlling displacement in a variable displacement compressor of an automobile air conditioning system entails detecting the temperature and humidity level of air entering the evaporator, setting a target air probe temperature from inside the automobile, and reading the evaporator air-out temperature at the temperature probe. From these parameters, the evaporator suction pressure can be calculated as can the load on the evaporator and the refrigerant flow rate so that the compressor swash plate angle, and thus, the compressor displacement, can be adjusted. After adjusting the compressor swash plate angle, calculating the absolute value of a difference between the actual air probe value and the vehicle occupant's air probe setting can be performed. If the absolute value is less than 0.5 degrees Fahrenheit, then the compressor stroke can be maintained, but if it is not, then the iteration must again be performed.

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 compressor connected to an external refrigerant circuit is disclosed. The compressor is provided with a housing, a passage forming member coupled to an outer surface of the housing, and a differential pressure type flow rate detector provided in the passage forming member. The flow rate detector obtains the pressure in an upstream passage and the pressure in a downstream passage to detect a refrigerant flow rate within the refrigerant passage. The flow rate detector is provided with an accommodation chamber, a partition body, a compression spring, and a spring seat defining a maximum stroke amount of the partition body. The spring seat exists closer to the passage forming member side than a partition surface comparting the housing and the passage forming member, and is in contact with the partition surface.

Abstract: A stability control algorithm is provided for a centrifugal compressor. The stability control algorithm is used to control a variable geometry diffuser and a hot gas bypass valve (when provided) in response to the detection of compressor instabilities. The stability control algorithm can adjust the position of a diffuser ring in the variable geometry diffuser in response to the detection of a surge condition or a stall condition. In addition, the diffuser ring in the variable geometry diffuser can be adjusted to determine an optimal position of the diffuser ring. The stability control algorithm can also be used to open a hot gas bypass valve in response to the detection of continued surge conditions.

Abstract: A variable capacity modular combined refrigerating installation, which has several modular refrigerating units. Each modular unit has a refrigerating circle, which includes a refrigerating compressor set (1), an evaporator (4) and a condenser (10). A flow control valve (6) is mounted at the refrigerating medium inlet/outlet port of the evaporator (4); and/or a flow control valve (11) is mounted at the inlet/outlet port of the condenser (10). The refrigerating compressor set (1) comprises an adjustable frequency motor (1A) and a compressor (1B) with magnetic suspend bearings. Each modular unit is also provided with an inlet pressure sensor (26) and/or discharge pressure sensor (27).

Abstract: An air conditioning system for a vehicle has a refrigerant cycle device which has an evaporator and a compressor and in which refrigerant is discharged from the compressor to be evaporated in the evaporator so that air passing the evaporator is cooled to be blown into a passenger compartment of the vehicle. The control unit drives the compressor at a control value which is determined based on at least one of a pressure of the refrigerant in the refrigerant cycle device and an outside-air temperature outside the passenger compartment, when the control unit actuates the compressor.

Abstract: A sensor array, particularly for vehicle air conditioners, having a housing, in which an electronic unit, a first sensor element connected with the electronic unit for measuring a first physical parameter, and a second sensor element connected with the electronic unit for measuring a second physical parameter, are arranged. The electronic unit has an electric signal output and an analyzing module which, as a function of momentary measuring values of the physical parameters, according to a defined selection logic, determines which of the measured physical parameters is to be considered to be the momentarily relevant parameter, and which switches a sensor signal formed on the basis of the momentarily relevant parameter to the signal output.

Abstract: A system includes a plurality of distributed refrigeration units respectively coupled to discrete refrigeration circuits. Each refrigeration unit may include a variable compressor, a fixed compressor, a condensing unit, and a controller. The controller compares an operating condition of the refrigeration unit to a refrigeration circuit set point to select a compressor staging capable of achieving the refrigeration circuit set point.