Performance Evaluation and Optimization of A Refrigerant Distributor for Air Conditioner

Refrigerant mal-distribution in a distributor located at the inlet of a heat exchanger used for an air conditioning system plays an important role in the heat exchanger performance. Distribution performance in the distributor is greatly affected by the flow conditions as well as the geometrical parameters of the distributor. To clarify the distribution characteristics, it is essential to know flow rates of both liquid and vapor states at every branch tube after distribution. This paper proposes a relatively simple test method, which enables to measure the inlet quality and the flow rate of refrigerant at every branch of the distributor. By using the proposed evaluation method, optimization on the geometrical parameters of the distributor was conducted to reduce the refrigerant mal-distribution. It was confirmed that the optimized distributor was able to reduce the mal-distribution of the refrigerant over branches despite the flow condition changes. By the flow visualization of the refrigerant in the distributor, it was observed that certain amount of liquid refrigerant remained and swayed unstably at the bottom of the distributor. It is supposed that the liquid refrigerant behavior in the distributor great affects the distribution performance.