The heat source controller transmits the drive permission signal (SE) to the utilization controller when the compression element is drivable. The utilization controller opens a utilization expansion valve when heat exchange in a utilization heat exchanger is required, on condition that the utilization controller receive the drive permission signal (SE).

A refrigeration apparatus includes a heat source-side unit and a utilization-side unit that are connected to each other, and performs a refrigeration cycle in which a high pressure of a refrigerant reaches or exceeds a critical pressure. The refrigeration apparatus also includes a control unit configured to perform a first action of returning the refrigerant to the heat source-side unit when a stop condition of the utilization-side unit is satisfied, and a second action of prohibiting the first action when a pressure at the heat source-side unit is equal to or more than the critical pressure of the refrigerant. This configuration suppresses damage to a refrigerant storage reservoir and the like in returning the refrigerant to the heat source-side unit.

A system includes a flash tank and a thermal storage tank. The flash tank is configured to store refrigerant and discharge a flash gas. The thermal storage tank is fluidically coupled to the flash tank and configured, when a power outage is determined to be occurring, to receive at least a portion of the flash gas from the flash tank, and remove heat from the flash gas. When a power outage is determined not to be occurring, the thermal storage tank directs refrigerant to a compressor.

The refrigeration cycle apparatus includes: liquid-side connection piping that extends from liquid-side refrigerant piping; gas-side connection piping that extends from gas-side refrigerant piping; a refrigerant storage tank that stores refrigerant, an intake side thereof being connected to the liquid-side connection piping, and a discharge side thereof being connected to the gas-side connection piping; an inlet-side electromagnetic valve that is disposed on the liquid-side connection piping, and that is opened when there is no passage of electric current; an inlet-side check valve that is disposed on the liquid-side connection piping, and that allows the refrigerant to flow only toward the refrigerant storage tank; and a valve apparatus that is disposed on the gas-side connection piping, that is opened during passage of electric current to the inlet-side electromagnetic valve, and that is delayed before being shut off after passage of electric current to the inlet-side electromagnetic valve is stopped.

A refrigeration system having a refrigerant circuit including a condenser, a flow control device, an evaporator, and a compressor connected in series. The compressor is configured to circulate a cooling fluid through the refrigerant circuit. The refrigerant circuit has an inlet line fluidly connecting the condenser to the evaporator and a suction line fluidly connecting the evaporator to the compressor. A heater is positioned to heat the cooling fluid during a defrost mode, and a pressure control is coupled to the refrigerant circuit downstream of the evaporator. In the defrost mode, the pressure control apparatus is configured to increase system pressure during the defrost mode to maintain flow of refrigerant into the evaporator and to control flow of cooling fluid to the compressor.

A motor drive control device includes a three-phase rectifier; a boosting circuit including a reactor, a switching element, and a backflow preventing element and boosts a direct-current bus voltage supplied from the three-phase rectifier; a smoothing capacitor; an inverter circuit; a boosting control unit; an inverter control unit; and a circuit protecting unit suppresses a ripple current flowing through the smoothing capacitor. In the circuit protecting unit, a correlation of an on-duty ratio of the switching element included in the boosting circuit, the output power of the inverter circuit, and an estimated ripple current are set. On the basis of the on-duty ratio of the switching element, output power of the inverter circuit, and the correlation, the circuit protecting unit determines an estimated ripple current flowing through the smoothing capacitor. When the estimated ripple current exceeds a preset threshold, the circuit protecting unit suppresses the ripple current.

The absorbing device includes a hollow enclosed chamber including two pot parts. Open ends of the pot parts are connectable to each other by welding or soldering. Each of the pot parts is integrally formed in an opposing end of an air-conditioning conduit, wherein open ends of the pot parts are oriented toward each other. Each of the pot parts is provided with a reduced passage opening interconnected with an internal space of the air-conditioning conduit via a tapered section.

A system includes a high side heat exchanger, a flash tank, a first load, a second load, and a thermal storage tank. The high side heat exchanger is configured to remove heat from a refrigerant. The flash tank is configured to store the refrigerant from the high side heat exchanger and discharge a flash gas. The first load is configured to use the refrigerant from the flash tank to remove heat from a first space proximate to the first load. The second load is configured to use the refrigerant from the flash tank to remove heat from a second space proximate to the second load. The thermal storage tank is configured, when a power outage is determined to be occurring, to receive the flash gas from the flash tank, and remove heat from the flash gas.

An air conditioner includes an outdoor unit, a plurality of indoor units, a plurality of expansion valves which are provided upstream of indoor heat exchangers, a plurality of on-off valves which are provided upstream of the expansion valves, and control unit wherein when the indoor units include a stopping indoor unit and an operating indoor unit currently operating, and when a stopping of the stopping unit is due to thermostat-off operation, the control unit performs a procedure to stop the stopping unit, the procedure including closing an on-off valve that corresponds to the stopping unit and driving an indoor fan in the stopping unit until pressure in a part between the on-off valve and an expansion valve that corresponds to the stopping unit and pressure in a part downstream of the first expansion valve are equalized, fully opening the expansion valve, and stopping the indoor fan.

A refrigeration system with pressure balancing function includes a condensing unit, a first refrigerant delivery pipeline, and a pressure balance control device including a temperature control unit, a first refrigerant control valve and a refrigerant supply switching controller. The temperature control unit determines if the temperature of the evaporator is abnormal, generates a temperature adjustment trigger signal that shifts between adjustment level and non-adjustment level. The refrigerant supply switching controller will determine, based on the level of the temperature adjustment trigger signal, whether to output the valve-open signal to the first refrigerant control valve. When the temperature adjustment trigger signal received by the refrigerant supply switching controller is at the adjustment level, the refrigerant supply switching controller will not output the valve-open signal to the first refrigerant control valve, so that the first refrigerant control valve is closed to stop delivering the refrigerant to the first refrigerant delivery pipeline.