Abstract: A system and method for flooded start control of a compressor having a crankcase heater are provided. A control module receives sensed data from a sensor, determines a current rate of liquid migration into the compressor, and compares the current rate with first and second predetermined thresholds. The control module operates the compressor in a flooded-start control mode, including operating the compressor according to at least one cycle with a first time period when the compressor is on and a second time period when the compressor is off. The control module operates the compressor in the flooded start control mode when the current rate is greater than the first predetermined threshold, activates the crankcase heater when the current rate is between the first and second predetermined thresholds, and operates the compressor without the flooded start control mode when the current rate is less than the second predetermined threshold.

Abstract: A system may be operable to circulate a working fluid between first and second heat exchangers. The system may include a suction line, a low-side compressor, a high-side compressor and a discharge line. The low-side and high-side compressors may both be in fluid communication with the suction and discharge lines.

Abstract: A foreign substance prevention apparatus according to an embodiment of the present invention may comprise: a housing including a suction port which is a passage for sucking external air, and a discharge port for discharging the sucked external air; a fan which exists inside the housing and rotates so as to suck the external air; and a connection bracket for connecting the housing and a sensor.

Abstract: A compressor (22) has a housing assembly (40) with a suction port (24), a discharge port (26), and a motor compartment (60). An electric motor (42) has a stator (62) within the motor compartment and a rotor (64) within the stator. The rotor is mounted for rotation about a rotor axis (500). One or more working impellers (44) are coupled to the rotor to be driven by the rotor in at least a first condition so as to draw fluid in through the suction port and discharge the fluid from the discharge port. An inlet guide vane (IGV) array (174) is between the suction port (24) and the one or more impellers (44). One or more bearing systems (66, 68) support the rotor (64) and/or the one or more impellers (44). One or more main drain passages (120, 234 206; 120, 232, 202, 206) are coupled to the bearings to pass fluid along a drain flowpath from the bearings to a location (172) upstream of the impeller and downstream of the IGV array.

Abstract: A compressor system with a continuously variable oil injection orifice is structured to regulate a flow of oil from an oil reservoir into a compressor. The orifice includes a first valve member moveable in response to oil pressure toward a second valve member to define a continuously variable flow area. A biasing member urges the first valve member away from the second valve member.

Abstract: A turbo compressor that has a pressure equalizing tube that circulates a gas from a gear unit accommodation space toward an IGV accommodation space, and an oil separation device that is provided in the gear unit accommodation space to separate lubricating oil that is contained in the gas, in which the oil separating device has a suction duct that communicates with the pressure equalizing tube, and the suction duct has a centrifugal separation portion provided with a first demister, a second demister provided on the downstream side of the first demister in relation to the suction direction, and a curved passage provided between the first demister and the second demister.

Abstract: A vehicle drive apparatus includes a motor, a case, a cover member, a sensor, and a separate member. The case includes a reservoir to store liquid fluid. The sensor is provided in a first communication hole of the cover member and is fixed to the cover member. A second communication hole constitutes a part of a fluid flow path extending from an inside of the case to an outside of the case. The fluid flow path has an intake port through which the liquid fluid is to be drawn. The fluid flow path includes an inside fluid flow path provided from the second communication hole to the intake port. The separate member is fixed to the cover member to define the inside fluid flow path.

Abstract: A heat exchanger for cooling air, with a coolant onward-flow connection for feeding liquid coolant for cooling air and a coolant return-flow connection for discharging liquid coolant. For removing ice by melting accumulated ice in the heat exchanger, a heater is provided that is associated with an electrical heating element. An operational safety device prevents overheating of the heater. The operational safety device comprises a fault-current detection device. Such a heater, with a heating element for heating air for subjecting accumulated ice to heated air, and with such an operational safety device is provided. Also, a galley for a commercial aircraft is provided with a receiving space for trolleys, and a cooling device for cooling the receiving space. The cooling device comprises such a heat exchanger for cooling air.

Abstract: A turbo compressor includes a case; compression stages which are disposed in a plural number in a rotatable manner with respect to the case via a sliding part; an oil tank in which a lubricant oil to be supplied to the sliding part is stored; a pressure equalization pipe which communicates the oil tank with the vicinity of the inlet of the compression stage; and a check valve which allows only the movement of the fluid from the oil tank side to the compression stage side in the pressure equalization pipe.

Abstract: An air conditioning apparatus has a refrigerant circuit made up of plural indoor units connected to an outdoor unit, and the air conditioning apparatus has a capacity controlling part and a target refrigerant temperature mode setting part. The capacity controlling part controls the air conditioning capacity of the outdoor unit in such a way that the evaporation temperature of refrigerant in the refrigerant circuit becomes a target evaporation temperature, or in such a way that the condensation temperature of the refrigerant becomes a target condensation temperature. The target refrigerant temperature mode setting part is configured to seta target refrigerant temperature mode to either a target refrigerant temperature changing mode or a target refrigerant temperature fixing mode.

Abstract: An apparatus and method for measuring concentration of a liquid-state refrigerant of a nonazeotrope refrigerant mixture. A container is disposed in such a way that a liquid-state refrigerant mixture of the nonazeotrope refrigerant mixture in a saturated state is temporarily stored with set quality. By measuring temperature and pressure of the liquid-state refrigerant mixture, concentration of the liquid-state refrigerant can be calculated from a database regarding a relationship between a saturation vapor pressure, temperature, quality, and concentration of the previously-stored nonazeotrope refrigerant mixture in the saturated state. Thus, a configuration for measuring the concentration of the liquid-state refrigerant-absorbent mixture includes a container, a temperature sensor and a pressure sensor and thus is very simple and the cost for the configuration can be reduced. In addition, the container can be easily mounted on existing equipment without disturbance of a flow.

Abstract: This invention relates generally to oil lubricated helium compressor units for use in cryogenic refrigeration systems, operating on the Gifford McMahon (GM) cycle. The objective of this invention is to keep the oil separator and absorber, which are components in an oil lubricated, helium compressor, in an indoor air conditioned environment while rejecting at least 65% of the heat from the compressor outdoors during the summer. The balance of the heat is rejected to either the indoor air conditioned air, or cooling water. This is accomplished by circulating hot oil at high pressure to an outdoor air cooled heat exchanger and returning cooled oil to the compressor inlet, while hot high pressure helium is cooled in an air or water cooled heat exchanger in an indoor assembly that includes the compressor, an oil separator, an oil absorber, and other piping and control components. It is an option to reject the heat from the oil to the indoor space during the winter to save on the cost of heating the indoor space.

Abstract: A refrigerating cycle apparatus and a method of operating the same are provided. For a refrigerating cycle having a plurality of compressors connected in series for multi-stage compression, an inner space of each compressor and a pipe of the refrigerating cycle may be connected via an oil collection pipe, and oil may be discharged into the refrigerating cycle by pressure reversal during a pressure balancing operation, so as to allow the discharged oil to be collected into a high-stage compressor or a low-stage compressor. Accordingly, an amount of oil may be uniformly maintained in each of the plurality of compressors to prevent losses due to friction and/or increases in power consumption due to a lack of oil in one or more of the compressors. The structure of a device and pipes for performing oil balancing between the compressors may be simplified to enhance efficiency of the compressors.

Abstract: An air-conditioning apparatus includes an outdoor air temperature sensor detecting an outdoor temperature; a compressor temperature sensor detecting a temperature of an outer wall of a compressor; a liquid-level and concentration detection sensor detecting a liquid surface level in the compressor and a concentration of a lubricant oil in a liquid in the compressor; an electric heater heating the compressor; and a controller that carries out preheating to the compressor by driving the electric heater when a detection value of the outdoor air temperature sensor is higher than or equal to a detection value of the compressor temperature sensor and, further, when the liquid surface level detected by the liquid-level and concentration detection sensor is higher than or equal to a predetermined level and the concentration of the lubricant oil in the liquid is lower than a preset minimum required concentration.

Abstract: The present invention disclosures an oil balance device and a method for performing an oil balance operation between a plurality of compressor units, which are suitable for air conditioner units comprising at least two parallel connected compressor units. Each compressor unit comprises at least one parallel connected compressors. The oil balance device comprises an oil reservoir, a first pipe, a second pipe, a third pipe and a fourth pipe. The four pipes communicate with the oil reservoir respectively. Each pipe is provided with at least one valve to control the opening and the closing of the corresponding pipe.

Abstract: Methods of removing moisture from a compressor using a sorbent technology are provided. A dehydration device incorporating the sorbent technology is disposed in a system that contains a hygroscopic fluid. By passing the hygroscopic fluid over the sorbent technology, moisture is removed from the hygroscopic fluid. The systems include sealed devices and integral components for heating, ventilation, and air conditioning (HVAC) systems and refrigeration devices.

Abstract: The present invention provides a refrigerating machine oil composition for use in a compressor for a refrigerator in which a sliding surface of at least a part of constitutional members of the compressor is coated with a lubrication film-forming composition containing a resin having a heat distortion temperature of 100° C. or higher as a binder, and a solid lubricant, wherein the refrigerating machine oil composition contains a base oil made of a polyoxyalkylene glycol having a kinematic viscosity of from 3 to 50 mm2/s as measured at 100° C., and a compound selected from the group consisting of amide compounds, amidated amino acid compounds and aliphatic amines having a specific structural formula which compound is contained in an amount of from 0.

Abstract: An air conditioner includes a plurality of compressors, an intake passageway, a bypass unit, and an expansion valve. The intake passageway distributes a fluid to each of the compressors. The bypass unit includes a plurality of bypass pipes connected respectively to the compressors and a common bypass pipe to discharge the fluids from the compressors to the intake passageway. The expansion valve is provided to the bypass unit to control a flow of fluid from the common bypass pipe to the intake unit.

Abstract: An air conditioner (10) composed of a refrigerating apparatus includes a controller (90). A heating control section (91) of the controller (90) feeds electric current in an open phase state to an electric motor (62) of a compressor (30) to heat the compressor (30) in operation stop of the air conditioner (10). The heating control section (91) monitors the detection value of an outdoor air temperature sensor (72) during the operation stop of the air conditioner (10) and keeps on stopping feeding the electric current to the electric motor (62) during the time when the detection value decreases.

Abstract: An oil level detecting device for a compressor and an air conditioning system having the same are provided. The oil level detecting device may be provided in a compressor including a compression device that introduces and compresses a working fluid, a driving device mechanically connected to the compression device that operates the compression device, and a case that accommodates the compression device and the driving device thereinside and having an oil storage space that stores oil at a lower portion thereof. The oil level detecting device may include a detector including a supporting portion configured to be attached to the case and a detecting portion that protrudes inside the case. At least one property of the detecting portion may vary according to an oil level inside the case. The oil level detecting device may also include a signal processor including an electronic element having at least one reference property.

Abstract: When a compressor is in a stopped state and an outside air temperature change rate Tah exceeds zero, a first heating operation is started, and a heating capacity of a compressor heating portion is set in a range not more than a heating capacity upper limit Pmax based on the outside air temperature change rate Tah. A remaining refrigerant liquid amount Ms condensed in the compressor that had not been evaporated is acquired based on the outside air temperature change rate Tah and the heating capacity. If the outside air temperature change rate Tah is zero or below and the remaining refrigerant liquid amount Ms exceeds zero while the compressor is in a stopped state, a second heating operation is started, the compressor heating portion 10 is controlled based on the remaining refrigerant liquid amount Ms, and the refrigerant condensed in the compressor 1 is evaporated.

Abstract: The present invention relates to a control method of a refrigerator which operates a cooling cycle including two storage compartments, a compressor, a condenser, a valve, fans, and evaporators for cooling the respective storage compartments, with one of the fans (5) corresponding to the storage compartment for storing items at relatively low temperatures being activated for a set amount of time even after the compressor is deactivated at the completion of cooling of the storage compartment for storing items at relatively low temperatures.

Abstract: A turbo compressor includes a motor, an impeller which is rotationally driven as the rotative power of the motor is transmitted to the impeller, a gear unit which transmits the rotative power of the motor to the impeller, and an oil tank to which lubricant supplied to the gear unit is at least recovered, wherein the oil tank is a portion of a closed space formed by at least one of a motor housing surrounding the motor and an impeller housing surrounding the impeller.

Abstract: A climate control system and method for optimizing energy consumption in a hybrid electric vehicle (HEV) is provided. By varying evaporator temperatures based on occupant settings and environmental conditions, electric compressor speed can be optimized to provide the necessary cooling capacities resulting in energy savings. Determining the impact that increasing or decreasing engine cooling fan speed has on the overall energy consumption of the climate control system without affecting target discharge air temperature provides for energy saving opportunities. Optimizing energy consumption according to the provided strategy provides for improved fuel economy without sacrificing passenger comfort.

Abstract: The present invention provides a refrigerator oil composition which satisfies both sludge dispersibility and prevention of wear and seizing of sliding parts made of aluminum and/or iron, and a compressor and a refrigeration apparatus using the refrigerator oil composition. The refrigerator oil composition is characterized by comprising a base oil which is at least one member selected from mineral oils and synthetic oils, and at least one polyamide compound having two or more amide groups in the molecule and being present in an amount of 0.01 to 5% by mass based on the total amount of the refrigerator oil composition.

Abstract: Overhung axial compressor, chemical reactor and method for compressing a fluid. The overhung axial compressor includes a casing configured to be vertically split along a vertical axis for access to an inside of the casing and a removable cartridge. The removable cartridge is configured to fit inside the casing and to be detachably attached to the casing. The removable cartridge includes a shaft disposed along a horizontal axis, the shaft being configured to rotate about the horizontal axis, a bearing system attached to the removable cartridge and configured to rotationally support a first end of the shaft, and plural blades disposed toward a second end of the shaft such that the second end is overhung inside the casing. The compressor also includes a guide vane mechanism configured to connect to the removable cartridge, the guide vane mechanism being configured to adjust a flow of a fluid to the plural blades.

Abstract: A refrigerating cycle apparatus and a method of operating the same are provided. For a refrigerating cycle having a plurality of compressors connected in series for multi-stage compression, an inner space of each compressor and a pipe of the refrigerating cycle may be connected via an oil collection pipe, and oil may be discharged into the refrigerating cycle by pressure reversal during a pressure balancing operation, so as to allow the discharged oil to be collected into a high-stage compressor or a low-stage compressor. Accordingly, an amount of oil may be uniformly maintained in each of the plurality of compressors to prevent losses due to friction and/or increases in power consumption due to a lack of oil in one or more of the compressors. The structure of a device and pipes for performing oil balancing between the compressors may be simplified to enhance efficiency of the compressors.

Abstract: A compressor and an expander are provided in a refrigerant circuit of an air conditioner. In the compressor, refrigerator oil is supplied from an oil reservoir to a compression mechanism. In the expander, the refrigerator oil is supplied from an oil reservoir to an expansion mechanism. Internal spaces of a compressor casing and an expander casing communicate with each other through an equalizing pipe. An oil pipe connecting the compressor casing and the expander casing is provided with an oil amount adjusting valve operated on the basis of an output signal of an oil level sensor. When the oil amount adjusting valve is opened, the oil reservoir in the compressor casing and the oil reservoir in the expander casing communicate with each other to allow the refrigerator oil to flow through the oil pipe.

Abstract: When during a heating operation the value calculated by an oil amount calculation section (51) is equal to or above a predetermined value, a frequency control section (52) of a controller (50) increases the operating frequency of a compressor (21) in order to recover refrigerating machine oil in a refrigerant circuit (R).

Abstract: A refrigerant system includes a compressor with a discharge valve that temporarily restricts the compressor's outflow at startup so that the discharge pressure can quickly rise to force lubricant back to the compressor. The discharge valve also helps prevent an axial face of a rotor of a screw compressor from rubbing against a bearing housing axial face of the compressor's housing. When the system turns off under certain low ambient air temperature conditions, the valve closes to help prevent the system's evaporator from freezing up. The discharge valve includes a novel arrangement of a piston, a valve stem extending from the piston, and a valve plug pivotally attached to the valve stem. The pivotal connection ensures a positive seal between the valve plug and a valve seat. A somewhat restricted fluid passageway between the valve's discharge chamber and piston chamber helps prevent the valve from chattering as the valve opens.

Abstract: A refrigeration air conditioner includes a first equalizer pipe connecting a bottom portion of a first hermetic vessel, which contains a main compression mechanism and lubricating oil, to a bottom portion of a second hermetic vessel, which contains an expansion mechanism, a sub-compression mechanism, and lubricating oil. A second equalizer pipe connects a side of the second hermetic vessel at a position higher than a minimum oil level to a suction side of the main compression mechanism. The space within the second hermetic vessel is isolated from the expansion mechanism and the sub-compression mechanism, and the pressure within the second hermetic vessel is not dependent upon the pressure within the expansion mechanism and the pressure within the sub-compression mechanism.

Abstract: A refrigerating device that forms a refrigerating cycle in which a plurality of outdoor machines 1a and 1b provided at least with compressors 2a and 2b, condensers 4a and 4b, and accumulators 5a and 5b respectively and an indoor machine 20 provided with decompressing means 21 and an evaporator 22 are connected in parallel by piping, having oil return pipes 13a and 13b that return refrigerator oil stored in the accumulators into the compressors, an oil equalizing pipe 10 that connects the accumulators to each other, and a controller 30 that controls an operation of the compressor and on/off of an electromagnetic valve 12a deposed on the oil equalizing pipe.

Abstract: A refrigeration cycle system is disclosed. A compression unit 11 for compressing the refrigerant by the drive force of a vehicle engine 4 is arranged in a housing 10 of a compressor 1. The flow rate of the refrigerant discharged from the compression unit 11 is detected by a flow rate sensor 15 including a throttle portion 15b and a pressure difference detection mechanism 15a. The throttle portion 15b reduces the flow rate of the refrigerant discharged from the compression unit 11. The pressure difference detection mechanism 15a detects the pressure difference between the upstream side and the downstream side of the throttle portion 15b in the refrigerant flow thereby to detect the flow rate of the refrigerant discharged from the compression unit 11. An oil separator 12 for separating the lubricating oil from the refrigerant discharged from the compression unit 11 is interposed between the compression unit 11 and the flow rate sensor 15.

Abstract: In a refrigeration cycle device for a vehicle, a weak-inflammability refrigerant that does not ignite at a high-temperature heat source mounted in an engine compartment of the vehicle in a refrigerant single state is circulated in a refrigerant cycle. The refrigerant cycle includes a compressor for compressing and discharging the refrigerant. The compressor includes an oil separator that is located at a refrigerant discharge side of the compressor to separate a lubrication oil from the refrigerant and to return the separated lubrication oil to an interior of the compressor, a shutting portion configured to shut a reverse flow of the refrigerant at a refrigerant suction side of the compressor, and a driving portion located to drive the shutting portion. Furthermore, the driving portion causes the shutting portion to shut the reverse flow of the refrigerant when the refrigerant cycle is damaged.

Abstract: The present invention provides a refrigerator oil composition which satisfies both sludge dispersibility and prevention of wear and seizing of sliding parts made of aluminum and/or iron, and a compressor and a refrigeration apparatus using the refrigerator oil composition. The refrigerator oil composition is characterized by comprising a base oil which is at least one member selected from mineral oils and synthetic oils, and at least one polyamide compound having two or more amide groups in the molecule and being present in an amount of 0.01 to 5% by mass based on the total amount of the refrigerator oil composition.

Abstract: An oil level detecting device for a compressor and an air conditioning system having the same are provided. The oil level detecting device may be provided in a compressor including a compression device that introduces and compresses a working fluid, a driving device mechanically connected to the compression device that operates the compression device, and a case that accommodates the compression device and the driving device thereinside and having an oil storage space that stores oil at a lower portion thereof. The oil level detecting device may include a detector including a supporting portion configured to be attached to the case and a detecting portion that protrudes inside the case. At least one property of the detecting portion may vary according to an oil level inside the case. The oil level detecting device may also include a signal processor including an electronic element having at least one reference property.

Abstract: A refrigeration cycle apparatus (100A) includes a first compressor (101) that is an expander-compressor unit, a second compressor (102), and a controller (300). The controller (300) shifts, when an oil level 51 of a first oil pool (13) becomes equal to or lower than a specified level L, to an oil-equalizing operation in which a rotation speed of a first motor (12) is decreased only by a specified decrement and a rotation speed of a second motor (12) is increased by a specified increment, and an opening of a bypass valve (70) is increased so that a pressure or a temperature of a discharged refrigerant guided to a radiator (4) through a first pipe (3a) is kept approximately constant, and returns the rotation speeds of the first motor (11) and the second motor (12) as well as the opening of the bypass valve (70) to conditions before start of the oil-equalizing operation when a specified period of time has elapsed since the start of the oil-equalizing operation.

Abstract: In a refrigerant circuit (11), a compressor (20) and an expander (30) are provided separately. An expander casing (34) is connected to a delivery pipe (26) of the compressor (20) and high pressure refrigerant passes through the inside of the expander casing (34). Therefore, the compressor casing (24) and the expander casing (34) are equalized in their internal pressure. An oil distribution pipe (41) for connection of an oil sump (27) of the compressor (20) and an oil sump (37) of the expander (30) is provided with an oil regulating valve (52). The oil regulating valve (52) is controlled in response to a signal outputted from an oil level sensor (51). When the oil regulating valve (52) is opened, the oil sump (27) within the compressor casing (24) and the oil sump (37) within the expander casing (34) fluidly communicate with each other whereby refrigeration oil travels through the oil distribution pipe (41).

Abstract: A variable speed drive is provided for a compressor in a refrigerant system. When a low load situation has been determined by the refrigerant system controls, the variable speed drive moves the compressor to a lower speed mode of operation. In this case, if a speed is so low that it cannot ensure adequate oil lubrication of the compressor elements, then the motor speed is periodically increased to a level that will ensure proper lubrication. In this manner, a variable speed drive compressor can be operated at an extremely low speed to precisely match load demand on a refrigerant system. The invention can be extended beyond refrigerant system applications and to any oil-lubricated compressors whose lubrication is speed dependant.

Abstract: A compression system for an air conditioning system includes first and second compressors. The first compressor includes a first compression chamber in which a fluid introduced from an outside of the first compressor is compressed, and a first case defining a first space into which the fluid compressed in the first compression chamber is introduced. The second compressor includes a second case defining a second space into which the fluid compressed in the first compressor is introduced, and a second compression chamber in which the fluid introduced from the second space is compressed. The second compressor operates independently of the first compressor, and a connecting line connects the first and second compressors.

Abstract: A system has a compressor having a compression path between a suction port located to receive a working fluid and a discharge port located to discharge the working fluid. The system has means for controlling a flow of at least one of additional working fluid and lubricant responsive to changes in at least one pressure parameter.

Abstract: A control for a compressor motor is programmed to operate the motor at at least one low capacity and at least one higher capacity. The control is operable to estimate an amount of oil which will have migrated from said compressor shell, at least when the compressor is operating at the lower capacity rate. The motor control moves the compressor motor from the lower capacity to at least one higher capacity once the estimated quantity of oil exceeds a predetermined limit. The capacity may be related to space.

Abstract: A compressor system includes a first compressor, which has a first low side oil sump, in a first shell and a second compressor, which has a second low side oil sump, in a second shell. The first and second compressors are connected in series. There is an oil transfer conduit connected between the first low side sump of the first compressor and the second low side sump of the second compressor. The system also includes a normally open check valve in the oil transfer conduit. A method for effecting oil balance in a compressor system, the method includes establishing a first compressor in a first shell having a first low side oil sump and establishing a second compressor in a second shell having a second low side oil sump. The first and second compressors are connected in series. The method also includes positioning an oil transfer conduit between the first low side sump and the second low side sump and positioning a normally open check valve in the oil transfer conduit.

Abstract: A compression system for an air conditioning system includes first and second compressors. The first compressor includes a first compression chamber in which a fluid introduced from an outside of the first compressor is compressed, and a first case defining a first space into which the fluid compressed in the first compression chamber is introduced. The second compressor includes a second case defining a second space into which the fluid compressed in the first compressor is introduced, and a second compression chamber in which the fluid introduced from the second space is compressed. The second compressor operates independently of the first compressor, and a connecting line connects the first and second compressors.

Abstract: A refrigerating system includes: an evaporator (2) for performing a cooling operation as a refrigerant is evaporated; a compressor (4) for compressing the refrigerant discharged from the evaporator as a mover is reciprocally moved; a condenser (86) for changing the refrigerant compressed in the reciprocating compressor to a liquid refrigerant; and a capillary tube (8) for decompressing the refrigerant discharged from the condenser and transferring it to the evaporator. Hydrocarbon consisting of carbon and hydrogen, a sort of natural refrigerant, is used as the refrigerant, and a paraffin-based lubricant, a sort of a mineral oil, is used as the lubricant, so that a lubricating performance and a performance of the refrigerating system can be improved.

Abstract: A method includes operating a variable-speed compressor in a refrigeration system carrying a refrigerant-oil mixture at a varying compressor speed to provide cooling capacity in proportion to cooling demand on the refrigeration system, determining that increased oil return to the compressor compared to a current oil-return rate is desired, and increasing the speed of the compressor to be disproportionately high relative to the cooling demand to provide increased oil return to the compressor.

Abstract: In a hybrid compressor for a vehicle where a vehicle engine is stopped when the vehicle is temporally stopped, a pulley, a motor and a compressor can be driven in independent from each other, and are connected to a sun gear, planetary carriers and a ring gear of a planetary gear. A rotational speed of the motor is adjusted by a controller, so that a rotational speed of the compressor is changed with respect to a rotational speed of the pulley. Accordingly, production cost of the hybrid compressor and the size thereof can be reduced, while a cooling function can be ensured even when the vehicle engine is stopped.

Abstract: A method for controlling operations of an air-conditioner includes: a step in which when an operation load of an air-conditioner increases, if an outputted compressing capacity of the air-conditioner is smaller than a compressing capacity corresponding to the operation load and an operation frequency of the first compressor is a maximum frequency of the first compressor, a second compressor is operated; and a step in which when the operation load is reduced, if the outputted compressing capacity of the air-conditioner is greater than the compressing capacity corresponding to the operation load and the operation frequency of the first compressor is a minimum frequency of the first compressor, the second compressor is stopped.

Abstract: A vehicle air conditioning apparatus includes a refrigerant circulation circuit. The vehicle air conditioning apparatus has a variable displacement type compressor, a first pressure monitoring point, a second pressure monitoring point and an oil separator in the refrigerant circulation circuit. Also, the vehicle air conditioning apparatus has a control valve in the compressor. The compressor compresses refrigerant gas. Displacement of the compressor is variable. The refrigerant gas includes oil. The second pressure monitoring point is located more downstream than the first pressure monitoring point. The control valve controls the displacement based on differential pressure between the first and second pressure monitoring points. The oil separator is located between the first and second pressure monitoring points in order to separate the oil from the compressed refrigerant gas, thereby the oil separator serves as means for manifesting the differential pressure.

Abstract: An oil level detecting device for a compressor and an air conditioning system having the same are provided. The oil level detecting device may be provided in a compressor including a compression device that introduces and compresses a working fluid, a driving device mechanically connected to the compression device that operates the compression device, and a case that accommodates the compression device and the driving device thereinside and having an oil storage space that stores oil at a lower portion thereof. The oil level detecting device may include a detector including a supporting portion configured to be attached to the case and a detecting portion that protrudes inside the case. At least one property of the detecting portion may vary according to an oil level inside the case. The oil level detecting device may also include a signal processor including an electronic element having at least one reference property.