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.

An air conditioner (1A) as a refrigeration apparatus includes: a refrigerant circuit (2) including an evaporator (25), a first compressor (21), a vapor cooler (3), a second compressor (22), and a condenser (23) that are connected in this order; a heat release circuit (4) that allows a heat medium to circulate between the condenser (23) and a first heat exchanger (5) that releases heat to the atmosphere; and a heat absorption circuit (6) that allows a heat medium to circulate between the evaporator (25) and a second heat exchanger (7). The vapor cooler (3) is a heat exchanger that exchanges heat between a refrigerant vapor compressed by the first compressor (21) and the heat medium flowing in the heat release circuit (4) or the heat medium flowing in the heat absorption circuit (6).

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 compressor installation provided with one or more compressor elements and a heat recovery circuit in the form of a closed Rankine circuit in which a working medium circulates through one or more evaporators that act as a cooler for the compressed gas, and a condenser connected to a cooling circuit for cooling the working medium in the condenser, whereby an additional cooler is provided for each evaporator that is connected in series to an evaporator concerned, and which is calculated to be able to guarantee sufficient cooling by itself when the heat recovery circuit is switched off

A method for cooling with a refrigerant based cooling system includes circulating a refrigerant in a main flow path of a refrigeration cycle including an accumulator, compressor, condenser and an evaporator, diverting a portion of flow to a bypass flow path from a location along the main flow path that is downstream the compressor and upstream the condenser and combining flow through the bypass flow path with flow through the main flow path downstream the condenser and upstream from the evaporator. The rate of flow through the bypass flow path may be dynamically controlled.

An air-conditioning apparatus includes a refrigerant circuit in which a compressor, a refrigerant flow switching device, a heat source side heat exchanger, an expansion device, a heat medium heat exchanger, and an accumulator are connected, a heat medium circuit in which a pump, the heat medium heat exchanger, a heat medium flow control device, and a load side heat exchanger are connected, at least one or more bypass pipes provided in the refrigerant circuit so that the refrigerant discharged from the compressor bypasses at least either one of the heat source side heat exchanger and the heat medium heat exchanger, a bypass opening and closing device provided at the bypass pipe, and a controller configured to control the bypass opening and closing device to carry out a start-up control function of causing low-pressure gas refrigerant with a high degree of superheat to flow into the accumulator.

A refrigeration cycle apparatus includes a refrigerant circuit, by pipes, connecting a compressor, a flow switching device, a first heat exchanger, an expansion device, and a second heat exchanger. As refrigerant to be circulated through the refrigerant circuit, any one of a refrigerant having saturated gas temperature under standard atmospheric pressure that is higher than that of R32 and a refrigerant mixture mainly composed of the refrigerant is used. The refrigerant circuit includes an internal heat exchanger configured to exchange heat between the refrigerant flowing through a refrigerant-inlet side of the second heat exchanger and the refrigerant flowing through a refrigerant-outlet side of the second heat exchanger.

Systems, methods, and computer-readable mediums are provided for improving the efficiency of a filter-type oil separator in a cooling system including a compressor that pumps a mixture of lubricating oil and refrigerant through the filter-type oil separator. The filter type oil separator is configured to receive a first portion of the mixture from the compressor, and a bypass line is configured to bypass a second portion of the mixture around the filter-type oil separator. The bypass line ensures a sufficient amount of oil is present in the compressor.

A climate-control system includes a first compressor, a second compressor, a first heat exchanger, a second heat exchanger, and a third heat exchanger. The first compressor includes a first inlet and a first outlet. The second compressor is in fluid communication with the first compressor and includes a second inlet (e.g., a suction inlet), a third inlet (e.g., a vapor-injection inlet), a second compression mechanism, and a second outlet. The second and third inlets are fluidly coupled with the second compression mechanism. The second compression mechanism receives working fluid from the first compressor through the third inlet and discharges working fluid through the second outlet of the second compressor. The first and second compressors are in fluid communication with the first, second, and third heat exchangers.

An air conditioning apparatus includes an outdoor device that is configured to circulate refrigerant and that includes a compressor and an outdoor heat exchanger, a plurality of indoor devices configured to circulate water, and a heat exchange device connecting the outdoor device with the indoor device. The heat exchange device includes a heat exchanger configured to exchange heat between the refrigerant and the water, and a switch device configured to control flow of refrigerant between the indoor devices and the heat exchanger.