A control device and method for preventing the start and stop of heat source machines from being frequently repeated. The control device determining whether or not basic conditions for decreasing the number of machines are satisfied when the number of currently operating machines is increased by one is determined if a current operational status satisfies basic conditions for increasing the number of machines, and one heat source machine is started if it is determined that the basic conditions for decreasing the number of machines are not satisfied, and determining whether or not the basic conditions for increasing the number of machines are satisfied when the number of currently operating machines is decreased by one are satisfied if a current operational status satisfies the basic conditions for decreasing the number of machines, and one heat source machine is stopped if it is determined that the basic conditions for increasing the number of machines are not satisfied.

A control device and method for preventing the start and stop of heat source machines from being frequently repeated. The control device determining whether or not basic conditions for decreasing the number of machines are satisfied when the number of currently operating machines is increased by one is determined if a current operational status satisfies basic conditions for increasing the number of machines, and one heat source machine is started if it is determined that the basic conditions for decreasing the number of machines are not satisfied, and determining whether or not the basic conditions for increasing the number of machines are satisfied when the number of currently operating machines is decreased by one are satisfied if a current operational status satisfies the basic conditions for decreasing the number of machines, and one heat source machine is stopped if it is determined that the basic conditions for increasing the number of machines are not satisfied.

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.

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.

A heating medium compression apparatus includes: first and second compressors compressing a heating medium; suction side and discharge side pipings connecting the first and second compressors to a heat exchanger; a connection piping connecting a discharge side of the first compressor and a suction side of the second compressor in series; and a control unit controlling a flow rate of the heating medium flowing in the suction side piping, the discharge side piping, and the connection piping. The control unit alternatively connects the first or second compressor to the suction side and discharge side pipings, or connects the first and second compressors in series between the suction side and discharge side pipings and performs control such that the flow rate of the heating medium suctioned into the second compressor connected in series becomes higher than that of the heating medium discharged from the first compressor.

An economizer includes a separation wheel, a motor, and a liquid storage portion. The separation wheel is arranged and configured to separate refrigerant into gas refrigerant and liquid refrigerant. The separation wheel is attached to a shaft rotatable about a rotation axis. The motor is arranged and configured to rotate the shaft in order to rotate the separation wheel. The liquid storage portion is arranged and configured to store the liquid refrigerant. The economizer is adapted to be used in a chiller system including a compressor, an evaporator and a condenser.

A compressor suction pipe includes a bent portion at least including a first pipe segment on the most upstream side with respect to flow of a fluid to be compressed, a second pipe segment connected to a suction side of a compressor and extending in a direction different from the extension direction of the first pipe segment, and a third pipe segment disposed between the first pipe segment and the second pipe segment and extending in a direction different from the extension directions of the first and second pipe segments, and at least one partition extending at least from an intermediate portion of the first pipe segment at least to an intermediate portion of the second pipe segment in the bent portion and dividing an interior of the bent portion. The partition extends in a direction intersecting a virtual plane including an incircle that touches an axis of the first pipe segment on an upstream side of a downstream end of the first pipe segment and touches an axis of the second pipe segment.

A compressor suction pipe includes a bent portion at least including a first pipe segment on the most upstream side with respect to flow of a fluid to be compressed, a second pipe segment connected to a suction side of a compressor and extending in a direction different from the extension direction of the first pipe segment, and a third pipe segment disposed between the first pipe segment and the second pipe segment and extending in a direction different from the extension directions of the first and second pipe segments, and at least one partition extending at least from an intermediate portion of the first pipe segment at least to an intermediate portion of the second pipe segment in the bent portion and dividing an interior of the bent portion. The partition extends in a direction intersecting a virtual plane including an incircle that touches an axis of the first pipe segment on an upstream side of a downstream end of the first pipe segment and touches an axis of the second pipe segment.

Refrigeration systems and control methods therefor are described. The refrigeration systems include a main circuit to connect, through a pipeline, a multi-stage compressor, a condenser, an economizer, a main throttling element, and an evaporator. An air supply branch is configured to connect to the air outlet of the economizer and the intermediate stage air inlet of the multi-stage compressor. A liquid injection branch is configured to connect to the intermediate stage air inlet of the multi-stage compressor from a section having a high-pressure liquid-phase refrigerant in the main circuit. Through the design of the liquid injection branch, the liquid-phase refrigerant can be introduced when vibration or noise of the unit exceeds a limit. The liquid-phase refrigerant, in the form of droplets, can effectively absorb the sound wave energy in the compressor pipeline to reduce an overall discharge pulsation of the compressor and reduce the noise and vibration of the condenser.

A lubricant separator is disclosed. The lubricant separator can cause lubricant which is entrained with a heat transfer fluid (e.g., a lubricant—heat transfer fluid mixture) to coalesce and fall (e.g., via gravity) into a bottom portion of a lubricant tank assembly. The lubricant separator can also reduce a velocity of the lubricant—heat transfer fluid mixture as it enters the lubricant tank assembly. The velocity reduction can, for example, reduce an amount of splashing of the lubricant that occurs as the lubricant—heat transfer fluid mixture enters the lubricant tank assembly. The velocity reduction can also, for example, be relatively more conducive to lubricant droplets falling into the bottom portion of the lubricant tank assembly as the flow of the heat transfer fluid is provided to a heat transfer fluid return conduit of the lubricant tank assembly.