空调室外换热器分布式流路设计与实验验证

空调室外换热器通常使用流路数目均一的流路,使空调器无法在不同的制冷剂流动特性下均具有最佳的换热状态。本文提出了一种室外换热器的分布式流路方案,以提升空调器的全年换热性能。首先根据制冷剂在换热器内的沿程流动特性提出流路数目随制冷剂干度增大而增大的分布式流路方案;然后通过换热器仿真软件分析分布式流路的换热特性和阻力特性;最后通过实验验证了分布式流路对空调器性能的提升效果。结果表明,与采用固定流路的空调室外换热器相比,采用分布式流路的空调系统的全年性能系数APF提高了1. 8%～5. 8%;室外换热器的额定制热量、低温制热量、超低温制热量分别约提高了4. 3%、7. 5%、5. 9%。

Design and Experimental Validation of Distributed Flow Path for Outdoor Heat Exchanger of Air Conditioner

The flow path numbers of an outdoor heat exchangerare always constant from the inlet to the outlet and cannot vary with the different refrigerant properties between the inlet and the outlet, which results in bad heat transfer. This study proposes a distributed flow path for an outdoor heat exchanger to improve the annual performance factor (APF) of air conditioners. The distributed flow path, with an increased path number from the low-quality zone to the high-quality zone, is configured according to the refrigerant property of the entire outdoor unit. Both the heat transfer and the pressure drop of the outdoor heat exchanger with the distributed flow path were analyzed by heat exchanger simulation software. Finally, the advantages of the distributed flow path on the heat transfer capacity were experimentally validated. The results showed that, compared with air-conditioning outdoor heat exchangers with fixed flow paths, the APF of the air conditioner systems with distributed flow paths increased by 1.8% to 5.8%;the rated heating capacity, low-temperature heating capacity, and ultra-low-temperature heating capacity of outdoor heat exchangers also increased by approximately 4.3%, 7.5%, and 5.9%, respectively.