An air conditioning apparatus includes a first pump and a first intermediate heat exchanger connected in series, and a second pump and a second heat intermediate exchanger connected in series. A flow path switching mechanism including at least four pairs of first and second valves. The first valves select an outflow port of one of the first and second pumps, and the second valves select an inflow port of the other of the first and second pumps. A third intermediate heat exchanger operates as an auxiliary heat exchanger, and is detachably connected to one pair of first and second valves. A pipe is detachably connected to and communicating the inflow port and the outflow port of a second pair of the pairs of the first and second valves. At least one indoor heat exchanger is connected to a third pair of the first and second valves.

A refrigeration cycle apparatus includes: a refrigerant circuit; an oil reservoir; a first pipe that connects the oil separator and the oil reservoir, the first pipe being configured to send the refrigeration oil separated by the oil separator to the oil reservoir; a first valve provided at the first pipe; a second pipe that connects the oil reservoir and a suction side of the compressor; a second valve provided at the second pipe; a third pipe that connects the oil reservoir and the suction side of the compressor at a position lower than a position at which the second pipe is connected to the oil reservoir; and a third valve provided at the third pipe. The first to third valves are closed in a non-operational period of the compressor.

A method of operating a cooling system that has at least one evaporator containing a refrigerant and at least one adsorbent chamber containing adsorbent configured to provide adsorption of vaporized refrigerant from the at least one evaporator in a cooling mode and provide desorption of the refrigerant to the at least one evaporator in a recharging mode, the method including; controlling the adsorption and desorption of the refrigerant of the at least one adsorbent chamber between the cooling modes and recharging modes during a cooling cycle; ceasing desorption of the refrigerant from the at least one adsorbent chamber; allowing adsorption of the vaporized refrigerant from the at least one evaporator; and maintaining the at least one adsorbent chamber in an adsorbed state at the end of the cooling cycle in a storage mode.

A refrigeration system includes at least one refrigeration circuit 2. The refrigeration circuit 2 includes a compressor 10, a first heat rejecting heat exchanger 6, a second heat rejecting heat exchanger 8, an expansion valve 12 and a heat absorbing heat exchanger 4. The refrigeration circuit 2 further includes a heat recovery control valve 14 for controlling flow of the compressed refrigerant fluid between the first heat rejecting heat exchanger and the second heat rejecting heat exchanger. The first heat rejecting heat exchanger 6 is for receiving compressed refrigerant fluid from the compressor 10 and exchanging heat between the compressed refrigerant fluid and a second fluid to increase the temperature of the second fluid, for example for heat recovery by heating water. The second heat rejecting heat exchanger 8 is for receiving the compressed refrigerant fluid and exchanging heat with ambient air to cool the compressed refrigerant fluid.

A method of operating a transport refrigeration system comprises: controlling, using a controller (30), a plurality of components of the refrigeration system and monitoring, using the controller, a plurality of operating parameters of the refrigeration system. The controlling comprises operating at least one of a prime mover (26), heater (48), and electric generation device (24). The operating parameters comprise at least one of a speed of the prime mover and a voltage of the electric generation device. The method comprises detecting, using the controller, when at least one of a heating mode and a defrost mode is required; activating, using the controller, the heater when at least one of the heating mode and the defrost mode is required; comparing, using the controller, the voltage of the electric generation device to a selected voltage; and controlling, using the controller, the speed of the prime mover in response to the voltage of the electric generation device.

A refrigeration cycle apparatus includes a refrigerant circuit, a high-side pressure sensor, an outside air temperature sensor, an outdoor fan, a fan driving unit, and a controller. The controller includes a pressure prediction unit that predicts, based on a high-side pressure detected by the high-side pressure sensor, a predicted value of high-side pressure at the elapse of a set time, a fan rotation speed control unit that, during cooling operation in which an indoor heat exchanger acts as an evaporator, adjusts the rotation speed of the fan driving unit based on the outside air temperature detected by the outside air temperature sensor and the operating capacity of an indoor unit, and an intermittent fan control unit that, if the fan driving unit is running at a set lower limit rotation speed, and if the high-side pressure is below a target value, controls the fan driving unit to perform intermittent operation, the intermittent operation being performed by setting an ON time and an OFF time such that the predicted value predicted by the pressure prediction unit approaches the target value.

A method of initiating a defrost cycle using a controller of a heat pump system includes measuring a temperature of an evaporator coil and determining whether the temperature of the evaporator coil is less than a freezing temperature. Responsive to a determination that the temperature of the evaporator coil is less than the freezing temperature, determining whether a current dew point temperature of air is greater than the temperature of the evaporator coil. Responsive to a determination that the current dew point temperature of air is greater than the temperature of the evaporator coil, calculating a frost-collection rate. Determining whether the frost-collection rate is greater than a frost-collection-rate threshold, and, responsive to a determination that the frost-collection rate is greater than the frost-collection-rate threshold, initiating a defrost cycle.

A refrigeration cycle apparatus includes a refrigerant circuit in which refrigerant circulates in the order of a compressor, an oil separator, a first heat exchanger, a decompressing apparatus, and a second heat exchanger and returns to the compressor. The refrigeration cycle apparatus further includes: an oil reservoir configured to store refrigeration oil; a first pipe and the oil reservoir, the first pipe being configured to send the refrigeration oil separated by the oil separator to the oil reservoir; a second pipe that connects the oil reservoir and a suction side of the compressor; a third pipe that connects the oil reservoir and the suction side of the compressor at a position lower than a position at which the second pipe is connected to the oil reservoir; and a heater configured to heat the refrigeration oil separated by the oil separator.

A method for controlling a vapour compression system having an ejector includes, in the case that a pressure difference between a pressure prevailing in the receiver and a pressure of refrigerant leaving the evaporator decreases below a first lower threshold value, the pressure of refrigerant leaving the heat rejecting heat exchanger is kept at a level which is slightly higher than the pressure level providing optimal coefficient of performance.

Provided is a refrigeration cycle apparatus configured to perform a heating operation and a simultaneous heating and hot-water supply operation. The refrigeration cycle apparatus is configured to execute an operation mode circulating refrigerant through, in order, a discharge outlet of a compressor, a first heat exchanger, an expansion device, a second heat exchanger provided to a water tank, and a suction inlet of the compressor, and causing the refrigerant flowing through the second heat exchanger to evaporate by heat generated by a heat source provided to the water tank.