Abstract: With the implementation of seasonal energy efficiency of variable frequency air conditioning in a large area of the world, the energy efficiency requirements of variable frequency air conditioning are becoming higher and higher, among which the design of evaporator has a great influence on the performance of air conditioning, and the flow path research of evaporator has become a key factor to improve the performance. By studying the evaluation method and energy efficiency calculation formula of APF in Japan, the energy efficiency of intermediate point accounts for 80% of the calculation of APF in Japan. HXSim Copper Alliance heat exchange simulation software was used to simulate the refrigeration capacity of the two evaporator flow paths, and the experimental verification was carried out on the split air conditioner of 2.8 kW heat pump exported from Japan. The comparative analysis found that the energy efficiency of the intermediate point was greatly improved by the fewer inlet and more outlet flow paths of the evaporator, thus the APF could be improved to a large extent.

Key words: Less in and more out, APF, Flow path, Intermediate energy efficiency, Evaporator