A method for conditioning air in a test space of a test chamber which receives test material. A temperature in a range of −20° C. to +180° C. is established within the test space with a cooling device. The cooling device includes a cooling circuit with a refrigerant, a heat exchanger, a compressor, a condenser and an expansion element. An internal heat exchanger of the cooling circuit is connected to a high-pressure side of the cooling circuit upstream of the expansion element and downstream of the condenser and to a low-pressure side of the cooling circuit upstream of the compressor and downstream of the heat exchanger and is used to cool the refrigerant of the high-pressure side. A zeotropic refrigerant is used and the internal heat exchanger is used to cool the refrigerant of the high-pressure side to lower an evaporation temperature at the expansion element.

There is disclosed a reversible heat pump system 100 and a method of operating a reversible heat pump system to control the temperature of a process fluid of a chiller system 500. In a cooling mode, a working fluid is circulated for co-current flow with a process fluid at a heat exchanger 104 functioning as an evaporator heat exchanger, whereas in a heating mode, the working fluid is circulated for counter-current flow with the process fluid at the same heat exchanger 104 functioning as a condenser heat exchanger.

A cooling system for an aircraft includes a first cooling circuit having a first evaporator and a second evaporator, and a second cooling circuit having a third evaporator and a fourth evaporator. One of the first and second cooling circuits includes a first set of valves arranged to direct refrigerant through a first cooling sub-circuit, a second cooling sub-circuit, or both the first and second cooling sub-circuits based on ambient conditions. Two of the evaporators are installed on a first side of the aircraft, and the other two of the four evaporators are installed on a second side of the aircraft opposite the first side, and the first and second cooling circuits reject heat, via a heat exchanger, from their respective cooling circuit to air passing into an engine of the aircraft.

A cooling system for an aircraft includes a first cooling circuit having a first evaporator and a second evaporator, and a second cooling circuit having a third evaporator and a fourth evaporator. One of the first and second cooling circuits includes a first set of valves arranged to direct refrigerant through a first cooling sub-circuit, a second cooling sub-circuit, or both the first and second cooling sub-circuits based on ambient conditions. Two of the evaporators are installed on a first side of the aircraft, and the other two of the four evaporators are installed on a second side of the aircraft opposite the first side, and the first and second cooling circuits reject heat, via a heat exchanger, from their respective cooling circuit to air passing into an engine of the aircraft.

A heat pump device capable of efficiently and reliably preventing a liquid refrigerant from stagnating in a compressor an air conditioner, a heat pump water heater, a refrigerator, and a freezing machine including the heat pump device. The configuration is such that, when the compressor is under operation standby, a high-frequency voltage synchronizing with a carrier signal is supplied to the compressor motor to carry out the locked energization of the compressor motor. From respective inter-phase voltages, respective phase voltages, or respective phase currents of the compressor motor for a plurality of high-frequency energization cycles, the detection values for one high-frequency energization cycle are restored. A power value calculated using the restored detection values for one high-frequency energization cycle is controlled to coincide with a heating power command necessary for discharging the liquid refrigerant stagnated in the compressor to the outside of the compressor.

A heat pump device capable of efficiently and reliably preventing a liquid refrigerant from stagnating in a compressor an air conditioner, a heat pump water heater, a refrigerator, and a freezing machine including the heat pump device. The configuration is such that, when the compressor is under operation standby, a high-frequency voltage synchronizing with a carrier signal is supplied to the compressor motor to carry out the locked energization of the compressor motor. From respective inter-phase voltages, respective phase voltages, or respective phase currents of the compressor motor for a plurality of high-frequency energization cycles, the detection values for one high-frequency energization cycle are restored. A power value calculated using the restored detection values for one high-frequency energization cycle is controlled to coincide with a heating power command necessary for discharging the liquid refrigerant stagnated in the compressor to the outside of the compressor.

A chiller system is provided including a vapor compression circuit consisting of a fluidly coupled compressor, condenser, expansion valve, and evaporator. A refrigerant circulates through the vapor compression circuit. The evaporator is a direct exchange heat exchanger. Refrigerant provided at an outlet of the evaporator is a two-phase mixture including liquid refrigerant and vapor refrigerant. The vapor refrigerant comprises less than or equal to 85% of the two-phase mixture. A refrigerant to refrigerant heat exchanger is fluidly coupled to the circuit. The refrigerant to refrigerant heat exchanger is configured to convert the vapor refrigerant provided at the outlet of the evaporator into a superheated vapor.

A vehicle air conditioner capable of making a determination that the dehumidification is unnecessary in a vehicle interior early to make a prompt transition from a dehumidifying mode to a heating mode and reduce power consumption is provided. A control device executes a heating mode to let a refrigerant discharged from a compressor 2 radiate heat in a radiator, decompress the refrigerant, and then let the refrigerant absorb heat in an outdoor heat exchanger 7, and a dehumidifying mode to let the refrigerant flow into the outdoor heat exchanger without flowing to the radiator to radiate heat therein, decompress the refrigerant, and then let the refrigerant absorb heat in a heat absorber 9 and let an auxiliary heater 23 generate heat. The control device shifts from the dehumidifying mode to the heating mode on the basis of the heat absorber suction air temperature Tevain being lowered more than a target heat absorber temperature TEO.

The present disclosure provides an accumulating/receiving device for a heat pump system. The accumulating/receiving device includes a body, an inlet, a first outlet, and a second outlet. The body defines therein a space. The body is disposed downstream of an outside heat exchanger. The inlet is connected to the outside heat exchanger through a first conduit. The first outlet is connected to an inside heat exchanger through a second conduit. The second outlet is connected, through a bypass conduit, to a third conduit. A liquid of the refrigerant flows out of the body through the first outlet in a cooling mode. A vapor of the refrigerant flows out of the body through the second outlet in a heating mode.

In a case of a heating operation in which the use side heat exchanger functions as a condenser when an outside temperature is a predetermined low temperature, a low-outside-temperature heating operation start-up mode in which, while a refrigerant discharged from the compressor is caused to flow into the use side heat exchanger, a refrigerant is supplied to the injection port of the compressor via the injection pipe and part of the refrigerant that has transferred heat in the heat source side heat exchanger is supplied to the compressor, is followed by a low-outside-temperature heating operation mode in which the refrigerant discharged from the compressor is supplied to the injection port of the compressor via the injection pipe while the refrigerant being caused to flow into the use side heat exchanger.