A refrigeration machine control device according to an embodiment of the present invention serves to control a turbo refrigeration machine and is equipped with a pressure reduction rate identification unit for identifying a pressure reduction rate at which foaming does not occur in an oil tank, and a pressure adjustment unit for adjusting the pressure of an evaporator on the basis of the identified pressure reduction rate. The pressure reduction rate identification unit is equipped with: a refrigerant precipitation gas volume calculation unit for calculating the volume of refrigerant gas precipitated from lubricating oil when the pressure is reduced at a prescribed pressure reduction rate; and a determination unit for determining whether or not foaming is permissible on the basis of a comparison between the calculated volume and the volume on the surface of the oil in the oil tank.

A technique that allows a plurality of series-connected compressors in a refrigerant circuit to have equal amounts of oil in a more versatile manner is provided. A compression apparatus according to an embodiment in the disclosure includes series-connected compressors 10, 20 in a refrigerant circuit 1 that is to circulate a refrigerant; an oil separator 30 is provided in a discharge passage 50 of the compressor 10 of the compressors 10, 20, and separates oil from the refrigerant discharged from the compressor 10 and causes the refrigerant separated from the oil to flow downstream (intake passage 80); an oil return passage 70 returns the oil separated by the oil separator 30 to the compressor 10 neighboring upstream; an oil discharge outlet 10A is provided in the compressor 10; and an oil discharge passage 60 connects the oil discharge outlet 10A to an inlet of the oil separator 30.

A method of mitigating liquid-refrigerant migration includes comparing a requested compressor speed of a variable-speed compressor to a pre-defined threshold and, responsive to a determination that the requested compressor speed is greater than the pre-defined threshold, operating the variable-speed compressor at a first compressor speed that is less than the requested compressor speed.

A non-combustible mixed refrigerant having a low greenhouse effect and an application thereof, the mixed refrigerant comprises the following components in mass fractions: 4-31.5% of R125, 50-80% of R1234ze (E) and 12-22% of R1234yf. Under the cooperation of each component dosage range, the mixed refrigerant becomes non-combustible, the ODP is 0, and the GWP is not greater than 1000. The present invention may be used in a refrigeration system, does not destruct ozone, reduces the greenhouse effect, and has a low slip temperature, relating to ternary azeotropic or near-azeotropic refrigerants, and being beneficial for the stable operation of a refrigeration system. The mixed refrigerant may also be used as a foaming agent or an aerosol propellant, and has the advantages of being non-combustible, having a low ozone destruction index, and being environmentally friendly, safe and reliable.

Embodiments of the present invention provide a lubricant management system (100) in a heat flux management system for an electric vehicle (150), comprising a vehicle air conditioning circuit comprising a refrigeration cycle refrigerant circuit (6) comprising at least a heat pump condenser (17) in thermal communication with a heat source (19), first and second evaporators (31, 131) each associated with an expansion valve (29, 129), and a refrigerant compressor (11), wherein the components are fluidly connected to one another by a refrigerant line (9,45), an accumulator (37) having a lubricant storage capacity and comprising lubricant delivery means (38), the accumulator being fluidly coupled in the refrigerant line downstream of the first and second evaporators (31, 131) and upstream of the refrigerant compressor (11), wherein the first evaporator and the second evaporator are fluidly connected in parallel downstream of the heat pump condenser (17) and upstream of the accumulator (37) and the associated expansion valves (29, 129) are operable to control a refrigerant flow rate through the first and the second evaporators (31, 131) sequentially to flush lubricant from the first and second evaporators to the lubricant storage capacity of the accumulator (37).

A refrigerant circuit includes a compressor, a high-pressure side heat exchanger, a decompressor, and a low-pressure side heat exchanger, which are annularly interconnected by a refrigerant pipe, and is configured to circulate refrigerant. The refrigerant circuit performs an oil recovery operation based on an operation history of the compressor ring a normal operation of the refrigerant circuit and an amount of oil in the compressor detected by an oil depletion sensor.

A scroll compressor includes an orbiting bedplate. The orbiting bedplate has: an oil passage through which oil supplied from an oil supply passage flows outward in a radial direction of the orbiting bedplate; a lap-side oil supply hole that causes the oil passage to communicate with a lap-formation surface of the orbiting lap at which the orbiting lap is formed; and a thrust-surface-side oil supply hole that causes the oil passage to communicate with a thrust surface of the orbiting bedplate that is opposite to the lap-formation surface of the orbiting bedplate. In the oil passage, an opening and closing mechanism is provided. The opening and closing mechanism closes the thrust-surface-side oil supply hole when the pressure of oil that is drawn from an oil sump by an oil pump and supplied into the oil passage is low, and opens the thrust-surface-side oil supply hole when the pressure of the oil is high.

This refrigeration apparatus (1) includes a main refrigerant circuit (2) including a positive displacement compressor (4), a condenser (6), an expansion valve (8), and an evaporator (10), through which a refrigerant circulates successively in a closed loop circulation, and a lubrication refrigerant line (18) connected to the main refrigerant circuit (2) between the condenser (6) and the expansion valve (8) or to the condenser (6), in which circulates a portion of the refrigerant of the main refrigerant circuit (2) and connected to the compressor (4) for lubrication of said compressor (4) with the refrigerant. The refrigeration apparatus includes a lubrication refrigerant tank (20) connected to the lubrication refrigerant line (18) upstream the compressor (4), the lubrication tank (20) being configured to store liquid refrigerant for lubrication of the compressor (4) and the lubrication refrigerant tank (20) comprises means (32, 34; 38, 40) to cool down the refrigerant.

Methods are directed towards dynamically determining refrigerant film thickness at the rolling-element bearing and for dynamically controlling refrigerant film thickness at the rolling-element bearing. Further, an oil free chiller system is configured for dynamically determining refrigerant film thickness at the rolling-element bearing of the oil free chiller system, wherein the oil free chiller system is also configured for dynamically controlling refrigerant film thickness at the rolling-element bearing of the oil free chiller system.

A linear compressor according to the present disclosure may include a cylinder provided with at least one groove, a piston reciprocating within the cylinder, a motor configured to provide a driving force to move the piston within the cylinder, an inverter configured to perform a switching operation to transmit electric power to the motor, and a controller configured to receive temperature information from the electronic device and control the inverter to preheat the motor based on the received temperature information.