A refrigerant cycle apparatus, that circulates a flammable refrigerant in a refrigerant circuit, includes: a gas-side cutoff valve; a liquid-side cutoff valve, where the gas-side cutoff valve and the liquid-side cutoff valve are disposed on opposite sides of a first portion of the refrigerant circuit; a detection unit that detects refrigerant leakage from the first portion into a predetermined space; and a control unit that sets a cutoff state in the gas-side cutoff valve and the liquid-side cutoff valve when the detection unit detects the refrigerant leakage from the first portion into the predetermined space. The cutoff leakage rate at the gas-side cutoff valve is higher than the cutoff leakage rate at the liquid-side cutoff valve.

A chemical heat pump includes a reaction section containing a heat storage material, a condensing section enabling a phase transition between water vapor and water, a connecting section connecting the reaction section and the condensing section, a valve adapted to open or close the connecting section, and a first fluid passage. The reaction section contains a plurality of heat storage materials having respective different conversion temperatures at which the heat storage material and the hydrate thereof are converted into each other. The plurality of heat storage materials and the first fluid passage are arranged so that the fluid flowing in the first fluid passage can perform heat exchanges with the heat storage materials in such a manner that the higher the conversion temperature of the heat storage material, the closer the position of the heat exchange to “the first side” of the first fluid passage.

An intermediate unit includes a liquid-side pipe, a first valve, and a refrigerant pressure sensor. The liquid-side pipe is connected to a liquid connection pipe connecting a heat source unit and a utilization unit together. A controller of the intermediate unit adjusts the opening degree of the first valve based on a value measured by the refrigerant pressure sensor. The pressure of a refrigerant to be sent through the liquid connection pipe from the intermediate unit to the utilization unit is adjusted by the first valve.

A compressor unit includes a first case, a compressor, a connecting port, and a shutoff valve. The connecting port includes a first connecting port and a second connecting port. The shutoff valve includes a first shutoff valve and a second shutoff valve. A heat source heat exchanger is accommodated in a second case. A utilization heat exchanger is accommodated in a third case. The compressor unit is disposed inside a building. The first connecting port is connected to the heat source heat exchanger via a first connection piping. The second connecting port is connected to the utilization heat exchanger via a second connection piping. The first shutoff valve shuts off flow of a refrigerant between the first connecting port and the heat source heat exchanger. The second shutoff valve shuts off flow of the refrigerant between the second connecting port and the utilization heat exchanger.

An apparatus using a heat pump includes a refrigerant circuit and a heat medium circuit. The refrigerant circuit is capable of performing a first operation, in which a load-side heat exchanger is used as a condenser, and a second operation, in which the load-side heat exchanger is used as an evaporator. A main circuit of the heat medium circuit has a branching part and a joining part. An overpressure protection device and a refrigerant leakage detecting device are connected to the main circuit. The overpressure protection device is connected to a connection part located between the load-side heat exchanger and one of the branching part and the joining part, or at the load-side heat exchanger. When leakage of refrigerant is detected, the state of a refrigerant flow switching device is set to a second state, an expansion device is set to a closed state, and a compressor is operated.

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.

A heat pump system for a vehicle delays the change of the direction of a directional valve for a given period of time and then conducts the change of the direction of the directional valve, upon receiving the mode change signal between an air conditioner mode and a heat pump mode, thus preventing the generation of the noise and vibration caused by the differential pressure of a refrigerant.

A method of refrigeration control through a refrigeration system of a refrigerated transport container includes performing a defrost cycle on the refrigeration system by activating a heat source; and restarting the refrigeration system after the defrost cycle has completed, wherein restarting the refrigeration system includes performing a liquid slugging avoidance process including: initiating a compressor of the refrigeration system at a speed; opening a pressure equalization valve in parallel with the compressor in response to the initiating; opening a liquid valve in series between a condenser and an evaporator after opening of the pressure equalization valve; and closing the pressure equalization valve after a period of time.

A refrigerant circuit includes a compressor operable to compress a refrigerant, an expansion valve, an outdoor heat exchanger, an indoor heat exchanger in a fresh air inlet to a conditioned space, a recovery heat exchanger in an extracted air outlet from the conditioned space, and a reversing valve operable to direct a direction of refrigerant flow between a cooling mode and a heating mode.

The present application provides a vacuum pump (15) for use during maintenance or commissioning of an HVAC-R system (1). The vacuum pump (15) has a pump (17) having a pump intake (22) for connection to the HVAC-R system (1), in particular one or more of a high pressure service port (14) and a low pressure service port (13) of the HVAC-R system (1). The vacuum pump (15) also includes a communications unit (19) that is configured to connect to a mobile communications network. The vacuum pump (15) also includes a pressure sensor arranged to detect a pressure in the HVAC-R system (1). The vacuum pump (15) also includes a control unit (18) configured to receive pressure data from the pressure sensor (21), control operation of the pump (17), and communicate with a remote device via the communication unit (19) and the mobile communications network. In examples, the remote device (20) may be a mobile phone or a tablet computer, or any device that can connect to a mobile communications network. Therefore, the vacuum pump (15) can remotely communicate updates to the remote device (20) over a mobile communications network, and can optionally also receive instructions or requests from the remote device (20) over a mobile communications network.