Lg Electronics Inc.

Bum Suk Kim

Hyuk Soo Lee

Sim Won Chin

Young Hwan Ko

Man Ho Chun

Sang Kyoung Park

Byung Soon Kim

Byoung Jin Ryu

Eung Yu Lee

Yong Hee Jang

An air conditioning system, including a condenser for condensing a refrigerant, a first expansion device for throttling the refrigerant passed through the condenser, a second expansion device for throttling the refrigerant passed through the first expansion device, an evaporator for evaporating the refrigerant passed through the second expansion device, a compressor for compressing the refrigerant passed through the evaporator and the refrigerant injected after branched between the first expansion device and the second expansion device, and a control unit for detecting a value of at least one operating parameter and determining a target opening degree of the first expansion device on the basis of a stored set value corresponding to the detected value of the operating parameter.

Air conditioning system

An air conditioning system includes a phase separator separating a gaseous refrigerant and a liquid refrigerant from a flowing refrigerant, an evaporator evaporating the liquid refrigerant separated by the phase separator, and at least one compressor including a first compressing part receiving the refrigerant via the evaporator and a second compressing part receiving both of the gaseous refrigerant separated by the phase separator and the refrigerant via the first compressing part.

Air-conditioner with multi-stage compressor and phase separator

It is possible to prevent that a liquid refrigerant is included in a refrigerant injected into a compressor. Accordingly, the risk of liquid compression of the compressor is greatly reduced, thereby decreasing the possibility of damage to the compressor and improving reliability and performance.

An air conditioning system is able to decrease the amount of refrigerant between a first expansion device and an injection valve and thus adjust the pressure of an injected refrigerant by decreasing the opening degree of the first expansion device and maintaining the opening degree of a second expansion device upon opening of the injection valve, thereby making the system stable upon opening of the injection valve. Furthermore, upon starting up a compressor, the opening degrees of the first and second expansion devices are partly decreased based on the start-up of the compressor and then gradually opened again, and upon completion of the start-up of the compressor, the opening amounts of the first and second expansion devices and the injection valve are controlled, thereby making the cycle more stable.

An air conditioning system can improve the cooling/heating performance of the system because the injection of refrigerant into the compressor is achieved. The air conditioning system can further improve the cooling/heating performance in a low temperature region by injecting refrigerant as a two-phase refrigerant or a superheated vapor state into the compressor. The air conditioning system can prevent damage of the compressor and further improve reliability by controlling such that the ratio of a liquid refrigerant in the refrigerant injected into the compressor may be less than a set value.

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Changwon-si, South Korea

Bum Suk Kim