A refrigerant system includes a compressor configured to pressurize a refrigerant fluid. The compressor includes a sump portion. A heater is situated to heat at least the sump portion. A controller is configured to selectively operate the heater to apply heat to at least the sump portion while the compressor is off and continue operating the heater when the compressor turns on until a temperature of the compressor or a temperature of fluid discharged from the compressor satisfies at least one criterion.

A refrigeration system has: (a) a fluid tight circulation loop including a compressor, a condenser and an evaporator, the evaporator having at least three evaporator zones, each evaporator zone having an inlet port, the circulation loop being further configured to measure the condition of the refrigerant with a refrigerant condition sensor disposed within the evaporator upstream of the evaporator outlet port; and control the flow of refrigerant to the evaporator based upon the measured condition of the refrigerant within the evaporator, and (b) a controller for controlling the flow rate of refrigerant to the evaporator based upon the measured condition of the refrigerant within the evaporator upstream of the evaporator outlet port.

In order to reduce the effect on a compressor caused by foaming in an oil tank, a control unit for controlling an oil pump starts the oil pump before a compressor is started (SA1), starts the compressor (SA4) when an oil supply differential pressure P satisfies a compressor startup condition during a reference time Tas from the starting of the oil pump (“Yes” in SA3), and extends the operation of the oil pump for a prescribed time without starting the compressor (Step SA5) when the compressor startup condition is not satisfied (“No” in SA3).

Provided is an air-conditioning device that includes an outdoor unit and an indoor unit, the outdoor unit including a compressor, the indoor unit being connected to the outdoor unit, the air-conditioning device including a heating means provided to the compressor, and configured to heat refrigerant in the compressor, and a controller configured to control the heating means. The controller includes a heat load learning unit configured to learn a heat load based on temperature data and air conditioning data, a stagnation prevention control start timing estimation unit configured to estimate a stagnation prevention control start timing based on the heat load obtained by learning, the stagnation prevention control start timing being a timing at which a stagnation prevention control of heating the compressor is started, and a device control unit configured to control the heating means such that the stagnation prevention control is performed by the heating means at the stagnation prevention control start timing estimated.

A refrigerant cycle system includes: a first refrigerant circuit; a second refrigerant circuit independent of the first refrigerant circuit; a heat source-side unit that includes a first heat source-side heat exchange unit and a second heat source-side heat exchange unit; a first use-side unit that includes a first use-side heat exchanger; a first liquid refrigerant connection pipe and a first gas refrigerant connection pipe that connect the first use-side unit to the heat source-side unit; a second use-side unit that includes a second use-side heat exchanger; and a second liquid refrigerant connection pipe and a second gas refrigerant connection pipe that connect the second use-side unit to the heat source-side unit.

The motor-driven compressor includes an electric motor, a housing, a compression portion, and an inverter device. The inverter device includes an inverter circuit, a current sensor, a coordinate converter, a speed controller, a current controller, a PWM controller, and a rotation angle estimator. The speed controller generates a d-axis current command value and a q-axis current command value such that a necessary torque to drive the electric motor occurs. The inverter device includes a heat-generating current command section that increases a temperature of the electric motor by changing the d-axis current command value and the q-axis current command value. The heat-generating current command section changes the d-axis current command value and the q-axis current command value so as to shift them in a direction in which a d-axis current value increases along a constant torque curve in a d-q coordinate system.

The present invention addresses a problem of providing a mixed refrigerant that combines three kinds of performances of having a refrigeration capacity (this may also be referred to as a cooling capacity) and of having a coefficient of performance (COP) equivalent to those of R410A, and of having a sufficiently small GWP. As a means for solving the problem, provided is a refrigerant-containing composition, wherein the refrigerant contains trans-1,2-difluoroethylene (HFO-1132 (E)), trifluoroethylene (HFO-1123) and 2,3,3,3-tetrafluoro-1-propene (R1234yf), and R32.

A heat exchanger includes a first collecting pipe, a number of heat exchange tubes and a partition plate. The heat exchange tubes are inserted into the first collecting pipe. By means of the partition plate, a first inner cavity of the first collecting pipe is divided into a first sub-cavity and a second sub-cavity. One end of each heat exchange tube is in communication with the first sub-cavity. In the process of a refrigerant entering the first collecting pipe, the refrigerant flows into the second sub-cavity firstly, and forms a severe turbulence effect after interacting with the heat exchange tubes inserted into the second sub-cavity. Then, the refrigerant flows into the first sub-cavity through holes provided in the partition plate, and then flows into the heat exchange tubes. As a result, the uniformity of the two-phase refrigerant distribution can be relatively improved.

A refrigeration cycle apparatus includes a refrigerant circuit in which refrigerant circulates in the order of a compressor, an oil separator, a first heat exchanger, a decompressing apparatus, and a second heat exchanger and returns to the compressor. The refrigeration cycle apparatus further includes: an oil reservoir that stores refrigeration oil; a first pipe that connects the oil separator and the oil reservoir, the first pipe sends the refrigeration oil separated by the oil separator to the oil reservoir; a second pipe that connects the oil reservoir and a suction side of the compressor; a third pipe that connects the oil reservoir and the suction side of the compressor at a position lower than a position at which the second pipe is connected to the oil reservoir; and a heater that heats the refrigeration oil separated by the oil separator.

A system for controlling a capacity of a compressor includes a motor of the compressor including a main winding connected at a connection point to an auxiliary winding and a drive configured to control a speed of the motor. The system includes a first switch configured to selectively connect the main winding to either a first line voltage or a first output of the drive, a second switch configured to selectively connect the connection point to either a second line voltage or a second output of the drive, and a third switch configured to selectively connect the auxiliary winding to either a capacitor or a third output of the drive. The system includes a solenoid valve configured to selectively either operate in a first capacity or a second capacity. The system includes a control module configured to control the drive, the first switch, the second switch, and the third switch.