An air conditioner and a control method thereof. The air conditioner includes an indoor unit including an indoor heat exchanger and an indoor fan, an outdoor unit connected to the indoor unit and including an outdoor heat exchanger, an outdoor fan, a compressor, an expansion valve, and a four-way valve, and at least one processor configured to perform a test operation by controlling the indoor unit and the outdoor unit. Based on an outdoor temperature being less than a predetermined reference temperature, the at least one processor is configured to determine whether the indoor unit and the outdoor unit operate normally, by continuously performing a heating operation and a defrosting operation during the test operation.

An air conditioner and a control method thereof. The air conditioner includes an indoor unit including an indoor heat exchanger and an indoor fan, an outdoor unit connected to the indoor unit and including an outdoor heat exchanger, an outdoor fan, a compressor, an expansion valve, and a four-way valve, and at least one processor configured to perform a test operation by controlling the indoor unit and the outdoor unit. Based on an outdoor temperature being less than a predetermined reference temperature, the at least one processor is configured to determine whether the indoor unit and the outdoor unit operate normally, by continuously performing a heating operation and a defrosting operation during the test operation.

A valve for a refrigeration system includes a valve body, a guide seat arranged in the valve body, a piston plug that has a metering slot and is axially movable relative to the guide seat to open and close the valve, and an adjustable valve stem that is axially movable to engage the piston plug. The piston plug is movable between a closed position in which the piston plug is seated against the guide seat and engaged with the valve stem to prevent fluid flow through the valve, a metering position in which the piston plug is moved away from the guide seat and engaged with the valve stem to enable a predetermined amount of forward fluid flow through the valve, and a check valve position in which the piston plug is seated against the guide seat to prevent reverse fluid flow through the valve.

A valve for a refrigeration system includes a valve body, a guide seat arranged in the valve body, a piston plug that has a metering slot and is axially movable relative to the guide seat to open and close the valve, and an adjustable valve stem that is axially movable to engage the piston plug. The piston plug is movable between a closed position in which the piston plug is seated against the guide seat and engaged with the valve stem to prevent fluid flow through the valve, a metering position in which the piston plug is moved away from the guide seat and engaged with the valve stem to enable a predetermined amount of forward fluid flow through the valve, and a check valve position in which the piston plug is seated against the guide seat to prevent reverse fluid flow through the valve.

There is disclosed heat pump, comprising: an internal heat exchanger configured to transfer heat from refrigerant in a liquid line pathway to refrigerant in a suction line pathway, to superheat the refrigerant upstream of a compressor; and a controller configured to: control an expansion valve to maintain a target superheat of refrigerant at a control location. The target superheat is variable and is determined based on one or more operating conditions of the heat pump. There is also disclosed a method of operating a heat pump and a simulation method to determine a variable superheat.

There is disclosed heat pump, comprising: an internal heat exchanger configured to transfer heat from refrigerant in a liquid line pathway to refrigerant in a suction line pathway, to superheat the refrigerant upstream of a compressor; and a controller configured to: control an expansion valve to maintain a target superheat of refrigerant at a control location. The target superheat is variable and is determined based on one or more operating conditions of the heat pump. There is also disclosed a method of operating a heat pump and a simulation method to determine a variable superheat.

A refrigeration cycle device includes: a refrigerant circuit which circulates a mixed refrigerant containing at least CF3I and HFO1123, the RC including a compressor, an expansion valve, an indoor heat exchanger, an outdoor heat exchanger and a refrigerant reservoir; an injection pipe having a first end at a first height within the refrigerant reservoir and a second end connected to the compressor; and an injection valve included in the injection pipe. The CF3I has the greatest fluid density among refrigerants contained in the mixed refrigerant. The first height is higher than a height at which an end of a refrigerant pipe, other than the injection pipe, is located within the refrigerant reservoir.

A refrigeration cycle device includes: a refrigerant circuit which circulates a mixed refrigerant containing at least CF3I and HFO1123, the RC including a compressor, an expansion valve, an indoor heat exchanger, an outdoor heat exchanger and a refrigerant reservoir; an injection pipe having a first end at a first height within the refrigerant reservoir and a second end connected to the compressor; and an injection valve included in the injection pipe. The CF3I has the greatest fluid density among refrigerants contained in the mixed refrigerant. The first height is higher than a height at which an end of a refrigerant pipe, other than the injection pipe, is located within the refrigerant reservoir.

Example implementations relate to a leak mitigation (LM) system. The LM system may include a collection tank, a first valve unit coupled to the collection tank, a second valve unit coupled to a cooling loop carrying a coolant, and an LM pump coupled between the first valve unit and the second valve unit. Moreover, the leak mitigation system may also include a controller operatively coupled to the first valve unit, the second valve unit, and the LM pump to operate, in an event of a leak of the coolant from the cooling loop, the first valve unit, the second valve unit, and the LM pump to transfer at least a portion of the coolant to the collection tank from the cooling loop via the second valve unit and the first valve unit.

Example implementations relate to a leak mitigation (LM) system. The LM system may include a collection tank, a first valve unit coupled to the collection tank, a second valve unit coupled to a cooling loop carrying a coolant, and an LM pump coupled between the first valve unit and the second valve unit. Moreover, the leak mitigation system may also include a controller operatively coupled to the first valve unit, the second valve unit, and the LM pump to operate, in an event of a leak of the coolant from the cooling loop, the first valve unit, the second valve unit, and the LM pump to transfer at least a portion of the coolant to the collection tank from the cooling loop via the second valve unit and the first valve unit.