A method of operating a refrigeration system (20) includes operating the refrigeration system in refrigeration mode. A current access condition into a refrigerated cargo space (22) is detected. At least one heat exchanger (32) in the refrigerated cargo space (22) is directed into a defrost mode during the current access condition. The refrigeration system (20) is directed into a refrigeration mode when the current access condition is no longer detected.

A vehicle air-conditioning device is a heat pump type vehicle air-conditioning device including an external heat exchanger that performs heat exchange between refrigerant flowing the inside thereof and outside air. With the vehicle air-conditioning device, a controller functions as a temperature-difference calculation unit that calculates the temperature difference ΔT between the refrigerant in a refrigerant flow path on the exit side of the external heat exchanger and the outside air, and in addition, the controller functions as a frost formation determination unit that determines that frost formation is caused on the external heat exchanger on the basis of the elapsed time to of a state in which the temperature difference ΔT is equal to or larger than a frost-formation temperature difference at which the frost formation may be caused on the external heat exchanger.

In a heat pump system, when a heat-shock determination portion determines that a difference between a coolant temperature in a coolant flow path and a coolant temperature in a heat source flow path is equal to or higher than a predetermined temperature, a flow-path switching portion mixes the respective coolants flowing through at least a bypass flow path and the heat source flow path together to flow into the coolant flow path.

Provided is a control device that performs protection control of a compressor without malfunction. The control device activates protection control on a compressor included in a refrigerant circuit based on a pressure value detected by a pressure sensor that is installed at a low-pressure side of the refrigerant circuit and a change over time of the pressure value.

A three fluid phase change material (PCM) heat exchanger for a vehicle comprises (i) an intake air channel having a first set of fins disposed therein and configured to receive and output intake air prior to combustion by an engine of the vehicle, (ii) a PCM layer surrounding the intake air channel and configured to cool the intake air, the PCM layer comprising a second set of fins, a PCM fluid that expands when freezing, and a set of elastomeric devices are configured to compress to compensate for the PCM fluid expansion during freezing, and (iii) a refrigerant channel surrounding the PCM layer and configured to circulate a refrigerant to cool the PCM layer to a solid, frozen state.

A method for directing thermal energy to an evaporator of a transport climate control circuit of a transport climate control system is provided. The method includes a controller determining whether the climate control circuit is operating in a start-stop cooling mode. Also, the method includes the controller determining a thermal energy charge of the thermal storage reservoir when the climate control circuit is operating in the start-stop cooling mode. The method also includes determining whether the thermal energy charge is greater than a charge threshold. Further, the method includes determining whether the climate control circuit is operating in a stop portion of the start-stop cooling mode when the thermal energy charge is greater than the charge threshold. The method further includes transferring thermal energy from the thermal storage reservoir to an evaporator when the climate control circuit is operating in the stop portion of the start-stop cooling mode.

A transport refrigeration unit is provided and includes a compressor, a condenser, an expansion valve, an evaporator, piping fluidly coupling the compressor and the condenser, a fluid loop to produce heated fluid from an engine, which is configured to drive operations of the compressor, a heat exchanger disposed in the refrigeration cycle such that the heated fluid thermally interacts with refrigerant of the refrigeration cycle and a hot gas bypass valve to control a quantity of refrigerant removed from the piping.

There is provided a vehicle air conditioning device of a heat pump system which improves comfortability when changing to heating only by an auxiliary heating device. The device includes a heating medium circulating circuit 23 to heat air to be supplied from an air flow passage 3 to a vehicle interior, and when shifting to the heating of the vehicle interior only by the heating medium circulating circuit 23 in a heating mode, a controller executes a shifting control to increase a heating capability of the heating medium circulating circuit 23 prior to stopping a compressor 2 and decrease a heating capability of a radiator 4 in accordance with the increase of the heating capability of the heating medium circulating circuit 23.

A heat pump system includes a heat pump cycle, a heat medium circulation circuit, and a refrigeration cycle device. The refrigeration cycle device is configured to perform a defrosting operation when a frost formation determiner determines that frost is formed. A throttle opening degree controller is configured to increase an opening degree in the defrosting operation. A pumping capacity controller is configured to increase a pumping capacity in the defrosting operation with increase of a required heating capacity required for heating a heating target fluid, the pumping capacity controller increasing the pumping capacity such that heat of refrigerant discharged from a compressor is transferred to heat medium in a first heat exchanger within a range in which a temperature of the refrigerant flowing into an outside heat exchanger is capable of melting the frost formed on the outside heat exchanger.

An air conditioning system of a vehicle having an internal combustion engine includes a condenser configured to receive refrigerant output by an electric compressor and transfer heat from the refrigerant within the condenser to air passing the condenser. A first evaporator is configured to receive refrigerant from the condenser when a first control valve is open and transfer heat from air passing the first evaporator to the refrigerant within the first evaporator. A first blower is configured to blow air across the first evaporator to a first section of a cabin of the vehicle. A second evaporator is configured to receive refrigerant from the condenser when a second control valve is open and transfer heat from air passing the second evaporator to the refrigerant within the second evaporator. A second blower is configured to blow air across the second evaporator to a second section of the cabin of the vehicle.