A refrigeration cycle apparatus includes a compressor, a four-way valve, a first outdoor heat exchanger, a first expansion valve, and an indoor heat exchanger. The four-way valve includes a casing, a first flow channel, a second flow channel, a flow channel switching piston, and a wall portion. The flow channel switching piston is configured to slide along an inner surface to switch between passing the refrigerant through the first flow channel and passing the refrigerant through the second flow channel. The wall portion is configured to slide along the inner surface together with the flow channel switching piston and is disposed with a space between the flow channel switching piston and wall portion to cover the flow channel switching piston.

An open-close valve unit includes a block body, a first open-close valve, and a second open-close valve. The block body includes a first main flow path and a second main flow path. The first main flow path has a first opening and a second opening. The second main flow path has a third opening and a fourth opening. The first open-close valve includes a first valve body movable to open and close the first main flow path. The second open-close valve includes a second valve body movable to open and close the second main flow path. The first open-close valve is in an open state when in an energized state. When the first open-close valve is in the energized state, the second open-close valve is in a de-energized state, and placed in an open state by a dynamic pressure of the fluid flowing in the second main flow path.

A refrigerant leak detection (RLD) and/or mitigation/containment (RLM/RLC) system/method for use in heating, ventilation, and air conditioning (HVAC) systems that incorporates a plurality of temperature and/or humidity sensors (THS), alarm status indicator (ASI), and digital control processor (DCP) is disclosed. The THS are positioned within the HVAC system (condenser coils (HCC), evaporator coils (HEC), air intake fans (AIF), air supply plenums (ASP), air return plenums (ARP), and/or temperature controlled environment (TCE)) and reports THS temperature readings to the DCP via a common temperature sensor bus (TSB) and/or a wireless temperature interface (WTI). The DCP interprets THS temperature readings in a closed control loop (CCL) to dynamically determine if a refrigerant leak has occurred within the HVAC system. If a leak is detected, the DCP activates the ASI and optionally one or more refrigerant control valves (RCV) is closed to limit refrigerant leakage in the HVAC system.

A refrigeration cycle system includes a refrigeration cycle apparatus and a refrigerant storage portion. The refrigeration cycle apparatus includes an indoor unit, an outdoor unit, a gas-side connection pipe, and a liquid-side connection pipe. The refrigerant storage portion stores the refrigerant present inside a refrigerant circulation path. The refrigerant storage portion communicates with the refrigerant circulation path through a first storage portion pipe and a second storage portion pipe. The first storage portion pipe causes a first refrigerant pipe of an outdoor refrigerant flow path and the refrigerant storage portion to communicate with each other, or causes the gas-side connection pipe and the refrigerant storage portion to communicate with each other. The second storage portion pipe causes the second refrigerant pipe of the outdoor refrigerant flow path and the refrigerant storage portion to communicate with each other.

A multi-air conditioner for heating and cooling may include at least one indoor unit, an outdoor unit, and at least one leak shut-off valve. The at least one indoor unit is installed in an indoor space and includes an indoor heat exchanger and an indoor expansion valve. The outdoor unit is connected to the at least one indoor unit via a refrigerant pipeline and includes an outdoor heat exchanger, a compressor, an outdoor expansion valve, and a four-way valve. The outdoor unit may decrease a pressure of the refrigerant pipeline when a refrigerant leak occurs from the refrigerant pipeline. The at least one leak shut-off valve is provided on the refrigerant pipeline and blocks a flow of refrigerant in the refrigerant pipeline when a refrigerant leak from the refrigerant pipeline occurs in the indoor space.

A heat pump apparatus includes: a refrigerant circuit, which is configured to circulate refrigerant, and includes a compressor, a heat source heat exchanger, an expansion mechanism, and an intermediate heat exchanger which are sequentially connected through a pipe; and a fluid circuit, which is configured to circulate a fluid, and includes the intermediate heat exchanger, a load heat exchanger, and a check valve which are sequentially connected through a pipe. A pressure regulating valve is provided to the heat pump apparatus. The pressure regulating valve is connected to a pipe connecting an outlet of the intermediate heat exchanger and an inlet of the load heat exchanger, and is configured to interrupt a flow passage of the fluid when the refrigerant leaks to the fluid, and pressure of the fluid is increased.

Provided is an air-conditioner which performs an appropriate control in the event of a leak of refrigerant. The air-conditioner (100) is provided with: a refrigerant circuit (10); a refrigerant leak sensor (25) which senses a leak of refrigerant in the refrigerant circuit (10); an indoor fan (Fi) which delivers air to the indoor heat exchanger (15); and an indoor control circuit 32 which, upon sensing a leak of refrigerant by the refrigerant leak sensor (25), controls the indoor fan (Fi) based on whether the refrigerant sealed in the refrigerant circuit 10 is flammable.

A heat-pump circuit may include an indoor heat exchanger, an outdoor heat exchanger, a compressor adapted to circulate a working fluid between the indoor and outdoor heat exchangers, and an expansion device disposed between the indoor and outdoor heat exchangers. A monitor for the heat-pump system may include a return-air temperature sensor, a supply-air temperature sensor, and a processor. The return-air temperature sensor may be adapted to measure a first air temperature of air upstream of the indoor heat exchanger. The supply-air temperature sensor may be adapted to measure a second air temperature of air downstream of the indoor heat exchanger. The processor may be in communication with the return-air temperature sensor and the supply-air temperature sensor. The processor may be programmed to determine a working-fluid-charge condition of the heat-pump system based on the first and second air temperatures.

When refrigerant leakage occurs, a controller in an air conditioner performs first shutoff control to open a liquid relay shutoff valve and close an indoor expansion valve and a gas relay shutoff valve on the basis of information from a refrigerant leakage detector.

A display device which displays operation information of an air conditioner in which an outdoor machine including an outdoor heat exchanger and an indoor machine including an indoor heat exchanger are connected. The display device includes a control unit that determines whether or not abnormality occurs in the outdoor machine or the indoor machine when the air conditioner operates, and a display unit which is controlled by the control unit so as to display time information and to display a plurality of operation information display regions for displaying operation information corresponding to the time information, in line. In a case where the control unit determines that the abnormality has occurred in the outdoor machine or the indoor machine, the control unit controls the display unit to display operation information of the outdoor machine or the indoor machine in which the abnormality has occurred, in the operation information display region.