Abstract: Under the requirements of F-gas regulations in Europe, R290 has become the preferred refrigerant for the fresh air ventilator. In order to achieve better product competitiveness, it is necessary to meet the limit of ≤150 g filling volume. A variety of optimization technical ideas are proposed. Considering the feasibility of technical implementation, focus on adopting microchannel technology to replace the originally configured 5 mm heat exchanger. The micro-channel heat exchanger is designed and simulated. Through the experimental comparative test research, the performance of the original product and the optimized product under different working conditions, it is found that the performance parameters of the optimization scheme still have space for improvement, which can meet the needs of the product. Finally, it is pointed out that the future can be further studied from the aspects of micro-channel design improvement and component optimization to improve the system performance.

Key words: R290, Fresh air ventilator, Heat pump, Microchannel