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: The present invention is capable of eliminating the line unit in an air conditioner that includes a plurality of heat source units, and hold increases in onsite line construction to a minimum while making it possible to adjust the amount of refrigerant in the air conditioner. The air conditioner includes a plurality of heat source units, a refrigerant liquid junction line and a refrigerant gas junction line, user units, and a refrigerant supply circuit. The refrigerant supply circuit is used in situations in which some of the plurality of heat source units stop operating in response to the operational burden of the user units, and is formed from refrigerant removal lines that remove refrigerant that accumulates inside stopped heat source units to the exterior thereof, and an oil equalization line and oil removal lines that connect the refrigerant removal lines of each stopped heat source unit and the intake sides of the compression mechanisms of the operating heat source units.

Abstract: Automatic oil removal from an ammonia evaporator/low pressure vessel in a refrigeration system is disclosed. A liquid refrigerant level controller is utilized to drain the oil. The controller works under the principle of fluid thermal conductivity. Oil having lower thermal conductivity as compared to liquid ammonia, activates the probe which in turn opens the valve to drain the oil accumulated in a trap of an evaporator or a low pressure vessel.

Abstract: In order to reduce refrigerant leakage from an automotive air conditioning system, the leakage paths are kept sealed by automatically reducing the output of a variable displacement compressor (12) after initial operation of the engine for a predetermined number of five minutes, and then only for a predetermined number of ten seconds, that is, so long as there has been an air conditioning on signal by the operator. After the reduction in output for ten seconds, the output of the compressor (12) is returned to full output for a predetermined number of two air-conditioning minutes, which is then followed by another ten seconds of reduced output.

Abstract: A method comprises the steps of (a) providing a refrigeration unit having a refrigerated or heated space and at least one measured operating parameter, (b) providing heat to the refrigerated space when the at least one measured operating parameter exceeds a first threshold, (c) terminating provision of heat when the at least one measured operating parameter exceeds a second threshold, and repeating steps b–c when the at least one operating parameter falls below the first threshold. In using this method, the unit can be operated continuously, with substantially higher refrigerant mass flow and evaporator pressure then in the prior art. Higher refrigerant mass flow rate and higher evaporator pressure improve oil return to the compressor, thus reducing the like hood of compressor damage due to oil pump out.

Abstract: The present invention relates to an air conditioning system provided with an outdoor unit having a compressor and an outdoor heat exchanger, an indoor unit having an indoor heat exchanger, and a gaseous refrigerant pipe connecting the indoor heat exchanger to the compressor. The present invention serves to make it possible to run such an air conditioning system in cooling mode continuously even when the outside air temperature is low by preventing the indoor heat exchanger from freezing. The air conditioning system is provided with one air-cooled outdoor unit and a plurality of indoor units connected in parallel to the outdoor unit. The indoor heat exchangers and the compressor are connected together by the gaseous refrigerant pipe. A pressure adjusting device is installed in the gaseous refrigerant pipe.

Abstract: A dual evaporator air conditioning system and method for use therewith to cool air in front and rear portions of a cabin of a vehicle. The dual evaporator air conditioning system includes primary and auxiliary HVAC units to cool the air in the front and rear portions of the cabin, respectively. The dual evaporator air conditioning system also includes a control system having cooling and non-cooling modes for each of the HVAC units. The control system automatically activates a heating element near the auxiliary evaporator in response to the auxiliary HVAC unit being in the non-cooling mode while the primary HVAC unit is in the cooling mode. The heating element heats the refrigerant in the auxiliary evaporator to prevent accumulation of liquid refrigerant and lubricating oil in the auxiliary evaporator when the auxiliary HVAC unit is in the non-cooling mode while the primary HVAC unit is in the cooling mode.

Abstract: Several control algorithms reduce the likelihood of insufficient oil return to the compressor. One algorithm is useful in a multi-circuit refrigerant system. A control reduces the cooling capacity of one of the circuits if the number of compressor start/stop cycles becomes excessive. By reducing the capacity, the control will reduce the number of compressor start/stop cycles for a circuit. In this manner, the oil continues to circulate through the circuit, and is more efficiently returned to the compressor. Another problem area associated with a poor oil return back to the compressor is when there is low mass flow rate of refrigerant circulating through the system. Various ways of increasing the refrigerant mass flow rate are disclosed to ensure proper oil return to the compressor. Also, if oil return problems are likely due to an undesirably high oil viscosity at the vapor portion of the evaporator or suction line, then steps are taken to reduce oil viscosity.

Abstract: Two liquid levels are sensed in the oil sump of a compressor to determine if sufficient oil and excess refrigerant are present prior to starting the compressor and appropriate steps taken, if necessary. At start-up, and during operation, the presence or flow of liquid refrigerant in the suction of the compressor is sensed and appropriate steps taken, if necessary.

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 controller for controlling a heater associated with the crankcase of a compressor senses electrical current flowing through the heater. The sensing is preferably accomplished by a transformer in combination with an amplifier providing a feedback signal to the controller. The transformer is installed in the line which carries the electrical current flowing through the heater. The controller checks for the presence of an appropriate voltage level from the amplifier. In the event that the voltage level is not above a threshold level, the controller sends an alarm signal indicating that the heater is not operating properly.

Abstract: Two liquid levels are sensed in the oil sump of a compressor to determine if sufficient oil and excess refrigerant are present prior to starting the compressor and appropriate steps taken, if necessary. At start-up, and during operation, the presence or flow of liquid refrigerant in the suction of the compressor is sensed and appropriate steps taken, if necessary.

Abstract: A method for refrigerant and oil collecting operation capable of assuring the cleanliness of the inside of an existing communication pipe at a low cost and installing, at a low cost, a new air conditioner, comprising a compressor (1), a heat source side heat exchanger (3), a decompressing mechanism (4), and a user side heat exchanger (5), comprising the steps of performing a pipe heating operation in a heating operation mode and performing a refrigerant and oil collecting operation to collect refrigerant to a heat source side heat exchanger (3), namely, with the refrigerant heated to a temperature higher than that where contaminants such as refrigerator oil inside a refrigerant circuit is dissolved into the refrigerant, performing the refrigerant and oil collecting operation so as to assure the cleanliness of the inside of the existing communication pipes (7, 8).

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: The present invention relates to an air conditioning system provided with an outdoor unit having a compressor and an outdoor heat exchanger, an indoor unit having an indoor heat exchanger, and a gaseous refrigerant pipe connecting the indoor heat exchanger to the compressor. The present invention serves to make it possible to run such an air conditioning system in cooling mode continuously even when the outside air temperature is low by preventing the indoor heat exchanger from freezing. The air conditioning system (1) is provided with one air-cooled outdoor unit (2) and a plurality of indoor units (3, 4, 5) connected in parallel to the outdoor unit (2). The indoor heat exchangers (23, 24, 25) and the compressor (11) are connected together by the gaseous refrigerant pipe (17). A pressure adjusting device (6) is installed in the gaseous refrigerant pipe (17).

Abstract: An air conditioning apparatus and control method thereof includes an inverter-type compressor and a two-stage variable-capacity compressor connected in parallel with their respective capacities controlled according to indoor air conditioning loads. Thus, the present invention is cost-competitive due to a capacity of the inverter-type compressor being lower than that of the two-stage variable-capacity compressor.

Abstract: A screw refrigerating apparatus comprising a refrigerant circulating passage including a screw compressor, a condenser, an expansion valve, and an evaporator is constituted such that a bypass flow passage branching at a part of the refrigerant circulating passage between the condenser and the expansion valve, routing through throttle means, and communicating with a rotor room within the screw compressor is provided. The screw refrigerating apparatus is capable of simplifying the structure, decreasing the size, decreasing labor of the maintenance, and the like.

Abstract: An air-conditioning system with a refrigerant medium circulating in a refrigerant loop has a variable-stroke compressor with a high-pressure outlet chamber, a drive chamber and an intake suction chamber. A first valve regulates a first flow of refrigerant medium from the high-pressure outlet chamber to the drive chamber, and a second valve regulates a second flow of refrigerant medium from the drive chamber to the intake suction chamber. The first and second valves operate independently of each other under the control of a control unit, and the variable stroke of the compressor is controlled by the first and/or second flow of refrigerant medium.

Abstract: An oil separator is provided on a bleeding channel inside the shaft 16. By integral rotation of the shaft 16 and a rotary valve, oil contained in a refrigerant gas is centrifuged via the oil separator. The separated oil is supplied to an interface between the rotary valve and a cylinder block, namely, a clearance portion of the rotary valve. The separated oil is also supplied into a clearance between a piston and a cylinder bore 12a via a suction port and a suction channel.

Abstract: An air conditioning apparatus and control method thereof includes an inverter-type compressor and a two-stage variable-capacity compressor connected in parallel with their respective capacities controlled according to indoor air conditioning loads. Thus, the present invention is cost-competitive due to a capacity of the inverter-type compressor being lower than that of the two-stage variable-capacity compressor.

Abstract: The present invention provides a gas heat pump-type air conditioner that can reliably notify a user that the time for changing the engine oil of the gas engine that drives the compressor has arrived without stopping the operation of the gas engine. In a gas heat pump-type air conditioner that forms a cooling cycle by circulating refrigerant using a compressor having a gas engine as a drive source, when the cumulative hours of operation t of the gas engine reaches a second predetermined time T2 (S3), a warning display A is displayed while the operation of the gas engine continues, and thereby the user is notified that the time for changing the engine oil has arrived (S4), and at the same time, after the initial stop procedure is carried out subsequent to reaching the predetermined time T2 (S5), a warning display B is displayed (S6), and the warning restoration operation procedure (S7) is carried out.

Abstract: An oil holding tank (40) is communicated to the case (10c) of the compressor (10). Part of the refrigerant discharged from the compressor (10) is introduced into the oil holding tank (40) so that the lubrication oil (L) is allowed to flow out from the oil holding tank (40) and the lubrication oil (L) which flows out is allowed to return to the case (10c). The presence of the lubrication oil (L) is detected from a comparison between the temperature (TK1) of the refrigerant introduced from the compressor (10) to the oil holding tank (40) and the temperature (TK2) of the lubrication oil (4) flowing out from the oil holding tank (40). On the basis of the result of the detection, it is judged whether or not the amount of the lubrication oil (L) in the case (10c) is appropriate.

Abstract: An evaporator for a refrigeration chiller includes a tube bundle in which at least a portion of the tubes of the tube bundle are immersed in a pool which include both liquid refrigerant and is lubricant. Liquid refrigerant and lubricant are deposited into the pool at a first pool location. Because of the vaporization of refrigerant that occurs within the pool, a pattern of flow is established and managed that causes the lubricant in the pool to migrate from the location of its deposit into the pool to a second pool location. An outlet is provided at the second pool location from which lubricant is drawn out of the evaporator.

Abstract: The present invention relates to the art of refrigeration and more particularly to a method of regulating the cooling process by controlling the oil pressure in a compressor. The system prevents the accumulation of the liquid refrigerant in the crankcase of the compressor and allows a compressor to continue to work without interruption.

Abstract: A compressor and oil separator assembly for compressing a fluid includes a suction end, a discharge end, and first and second rotors rotatably mounted between the suction and discharge ends. A discharge line communicates with the discharge end, and an oil separator communicates with the discharge line. An oil sump communicates with the oil separator and an oil supply line communicates between the oil sump and the rotors. A bleed line selectively communicates between the discharge line and the oil supply line for equalizing a pressure differential between the suction end and the discharge end without causing substantial backward rotation of the rotors or displacement of oil to the rotors through the oil supply line. Preferably, the assembly further includes a valve that defines a portion of the discharge line and is also coupled to the bleed line.