A refrigerating cycle apparatus includes: a compressor that compresses and discharges refrigerant; a radiator that makes the refrigerant discharged out of the compressor to radiate heat; a pressure reducing device that decompresses the refrigerant flowing out of the radiator; an evaporator that evaporates the refrigerant decompressed by the pressure reducing device; and a decompression control part that controls operation of the pressure reducing device. The decompression control part controls the operation of the pressure reducing device in a manner that a physical quantity which has correlation with a pressure of the refrigerant in the evaporator approaches a predetermined defrosting standard value when a time-priority defrosting mode is set.

An HVAC system includes a unit cooler, which includes a first evaporator coil, a second evaporator coil, and a blower. The HVAC system further includes a first sensor, a second sensor, a first valve, a second valve, and a controller. The controller actuates the blower to direct air to flow over the first evaporator coil and the second evaporator coil, receives measurements from the first sensor and the second sensor, initiates a defrost cycle for the first evaporator coil by transmitting instructions to close the first valve to prevent the flow of refrigerant into the first evaporator coil, transmits instructions to open the first valve when the defrost cycle for the first evaporator coil has terminated, and initiates a defrost cycle for the second evaporator coil by transmitting instructions to close the second valve to prevent the flow of refrigerant into the second evaporator coil.

A method to manage defrosting of a refrigeration plant provided with at least one compressor and at least one evaporator, including defining a plurality of defrosting modes, which can be selected by the manufacturer and/or by the end user, which are based on one or more functioning parameters of the refrigeration plant; such functioning parameters are detected by detection probes provided in the refrigeration plant such as pressure switches, thermostats, timing devices or other, associated with the compressor and/or the evaporator, or other; and memorizing the plurality of defrosting modes in an electronic device to manage the defrosting.

A heat pump water heater can include a refrigerant circuit, an evaporator coil in fluid communication with the refrigerant circuit, a fan configured to move air across the evaporator coil, one or more temperature sensors, a heating element located proximate an air flow path between the fan and the evaporator, and a controller. The controller can be configured to receive temperature data from the one or more temperature sensors and, in response to the temperature data, output instructions for the fan to move air across the heating element to the evaporator coil.

A refrigeration apparatus includes a compressor, a heat-source-side heat exchanger operable as a refrigerant evaporator or radiator, and a usage-side heat exchanger operable as a refrigerant evaporator or radiator. The heat-source-side heat exchanger is disposed inside a heat source unit having an exhaust port and an outdoor fan in an upper part, and an intake port in a side part. The heat-source-side heat exchanger includes first and second heat-source-side heat exchangers. Adjustable first and second heat-source-side flow rate adjusting valves are connected to liquid sides of the first and second heat-source-side heat exchangers, respectively. In a defrost operation in order to defrost the first and second heat-source-side heat exchangers, the opening degrees of the first and second heat-source-side flow rate adjusting valves are controlled so as to achieve a defrost flow rate ratio at which more refrigerant flows to the second heat-source-side heat exchanger than during an air-cooling operation.

An HVAC system includes a unit cooler, which includes a first evaporator coil, a second evaporator coil, and a blower. The HVAC system further includes a first sensor, a second sensor, a first valve, a second valve, and a controller. The controller actuates the blower to direct air to flow over the first evaporator coil and the second evaporator coil, receives measurements from the first sensor and the second sensor, initiates a defrost cycle for the first evaporator coil by transmitting instructions to close the first valve to prevent the flow of refrigerant into the first evaporator coil, transmits instructions to open the first valve when the defrost cycle for the first evaporator coil has terminated, and initiates a defrost cycle for the second evaporator coil by transmitting instructions to close the second valve to prevent the flow of refrigerant into the second evaporator coil.

The present invention relates to an energy saving refrigeration and defrosting system through 3 stage condensation heat exchangers. More specifically, the high-temperature vapor refrigerant in the refrigeration system is condensed using 3 stage condensation heat exchangers such as a tubular tube, a condensation heat exchange tank and a brine tank. This invention relates to an energy saving refrigeration and defrosting system using 3 stage condensation heat exchangers in place of a conventional refrigeration condenser.

A heater core for exchanging heat between a coolant and ventilation air to be blown into a vehicle interior is disposed in a high-pressure side heat-medium circulation circuit that allows for circulation of the coolant heated by a heat pump cycle. A radiator for exchanging heat between at least a part of the coolant flowing out of the heater core and a low-pressure refrigerant in the heat pump cycle is disposed in a low-pressure side heat-medium circulation circuit coupled to the high-pressure side heat-medium circulation circuit. Thus, excessive heat included in the coolant flowing out of the heater core and which is not used to heat the ventilation air can suppress frost formation on an exterior heat exchanger and can also defrost the exterior heat exchanger.

A system and method for controlling a refrigeration system is disclosed. The system includes a cooled compartment, at least one heat source selectively activated to provide heat, at least one sensor, and a controller. The sensor detects a temperature and a relative humidity of ambient air that surrounds the cooled compartment. The controller is in communication with the at least one heat source and the at least one sensor. The controller includes logic for calculating a dew point temperature based on the temperature and the relative humidity. The controller also includes logic for selecting a region of operation based on at least one of the dew point temperature and the relative humidity, where the region of operation is representative of ambient conditions that surround the cooled compartment. The controller further includes logic for determining if the at least one heat source is activated based on the region of operation.

Disclosed are a method and device for controlling an air conditioner. The air conditioner includes an outdoor heat exchanger, an indoor heat exchanger, a heat storage heat exchanger, a compressor, a four-way valve assembly, and a throttling assembly, wherein the outdoor heat exchanger is connected to the indoor heat exchanger by means of a first pipeline and a bypass, the outdoor heat exchanger is connected to the compressor by means of a second pipeline, the indoor heat exchanger is connected to the compressor by means of a third pipeline, the heat storage heat exchanger is arranged on the bypass, the throttling assembly is arranged on the bypass, the four-way valve assembly includes a first four-way valve and a second four-way valve, the first four-way valve is arranged on the second pipeline, and the second four-way valve is arranged on the third pipeline.