The present invention provides an inexpensive and stable refrigerant charging device and a refrigerant charging system by improving a charging speed and reducing costs while preventing liquid-back. The present invention includes a refrigerant charging flow path having a refrigerant charging port connected to a refrigerant flow path of an air conditioner, a valve provided at the refrigerant charging flow path, and a control device configured to control the valve. The control device includes a discharging superheat calculator configured to calculate the discharging superheat degree from a refrigerant temperature and a refrigerant pressure at a discharge side of a compressor, and a valve controller configured to control the opening and closing state of the valve based on the calculated discharging superheat degree calculated by the discharge super-heat calculator.

A metering device is fluidly coupled to the condenser coil. A distributor is fluidly coupled to the metering device. An evaporator coil is fluidly coupled to the distributor via a plurality of evaporator circuit lines. Are-heat coil is disposed adjacent to the evaporator coil. The re-heat coil includes a first fluid connection to the metering device via a re-heat return line and a second re-heat feed line. The re-heat coil includes a second fluid connection to the condenser coil via a connecting line and a condenser intake line. A first check valve is disposed between the connecting line and the condenser intake line. A second check valve is disposed between the re-heat return line and the second re-heat feed line.

This cold storage device comprises a compressor, a condenser, a throttling device, and an evaporator, which form a cooling medium circuit through which a mixture of a cooling medium, a lubricating oil, and an oil carrier circulates. The oil carrier molecular structure includes a carbon double bond and a chlorine atom bonded to one carbon atom forming the carbon double bond.

A dual reclaim coil with a smart control application is provided that allows the refrigerant inlet to the HVAC unit switch between the two sides of the condenser for heat reclaim for refrigerants such as CO.sub.2 which have a relatively low critical temperature compared to hydrofluorocarbon refrigerants. Heat reclaim after the exit of gas from the condenser utilizes the high temperature and pressure of the condenser/gas cooler outlet while a CO.sub.2 refrigerant system is operating above critical point. This occurs in hot ambient conditions, when the need for heating in the space is not as great as in the wintertime and the available heat at the condenser/gas cooler's outlet is sufficient to satisfy the heating load. When the CO.sub.2 refrigerant system is operating below the critical point, heat reclaim is carried out at the compressor discharge.

A dual reclaim coil with a smart control application is provided that allows the refrigerant inlet to the HVAC unit switch between the two sides of the condenser for heat reclaim for refrigerants such as CO.sub.2 which have a relatively low critical temperature compared to hydrofluorocarbon refrigerants. Heat reclaim after the exit of gas from the condenser utilizes the high temperature and pressure of the condenser/gas cooler outlet while a CO.sub.2 refrigerant system is operating above critical point. This occurs in hot ambient conditions, when the need for heating in the space is not as great as in the wintertime and the available heat at the condenser/gas cooler's outlet is sufficient to satisfy the heating load. When the CO.sub.2 refrigerant system is operating below the critical point, heat reclaim is carried out at the compressor discharge.

A liquid accumulator for a heat exchange system, includes a liquid accumulator housing provided with an air inlet, an air outlet, and a liquid inlet; and a cooling heat exchanger disposed in the liquid accumulator housing, wherein the cooling heat exchanger comprises an inlet end, a main body part, and an outlet end in sequence; the inlet end of the cooling heat exchanger is connected to the air inlet on the liquid accumulator housing; and the outlet end of the cooling heat exchanger is arranged to be higher than a working liquid level of a refrigerant in the liquid accumulator.

A method for controlling an operating discharge pressure in a multi-purpose HVAC system including an outdoor unit, and an indoor unit, the HVAC system including a plurality of flow control valves configured to isolate the indoor unit from the multi-purpose HVAC system, a compressor and a controller, operably coupled to a water heater module, the water heater module including at least one valve, the controller executing a method including operating the multi-purpose HVAC system in a water heating mode, monitoring the operating discharge pressure from the compressor; and generating a signal commanding at least one of the plurality of control valves to isolate the indoor unit from the outdoor unit and water heating module and direct high pressure refrigerant to the indoor unit when the operating discharge pressure is greater than or equal to a predetermined pressure value.

A method for controlling an operating discharge pressure in a multi-purpose HVAC system including an outdoor unit, and an indoor unit, the HVAC system including a plurality of flow control valves configured to isolate the indoor unit from the multi-purpose HVAC system, a compressor and a controller, operably coupled to a water heater module, the water heater module including at least one valve, the controller executing a method including operating the multi-purpose HVAC system in a water heating mode, monitoring the operating discharge pressure from the compressor; and generating a signal commanding at least one of the plurality of control valves to isolate the indoor unit from the outdoor unit and water heating module and direct high pressure refrigerant to the indoor unit when the operating discharge pressure is greater than or equal to a predetermined pressure value.

A metering device is fluidly coupled to the condenser coil. A distributor is fluidly coupled to the metering device. An evaporator coil is fluidly coupled to the distributor via a plurality of evaporator circuit lines. A re-heat coil is disposed adjacent to the evaporator coil. The re-heat coil includes a first fluid connection to the metering device via a re-heat return line and a second re-heat feed line. The re-heat coil includes a second fluid connection to the condenser coil via a connecting line and a condenser intake line. A first check valve is disposed between the connecting line and the condenser intake line. A second check valve is disposed between the re-heat return line and the second re-heat feed line.

A metering device is fluidly coupled to the condenser coil. A distributor is fluidly coupled to the metering device. An evaporator coil is fluidly coupled to the distributor via a plurality of evaporator circuit lines. A re-heat coil is disposed adjacent to the evaporator coil. The re-heat coil includes a first fluid connection to the metering device via a re-heat return line and a second re-heat feed line. The re-heat coil includes a second fluid connection to the condenser coil via a connecting line and a condenser intake line. A first check valve is disposed between the connecting line and the condenser intake line. A second check valve is disposed between the re-heat return line and the second re-heat feed line.