车用热泵用小管径管片式换热器性能研究

Feasibility Study of the Ф5 Tube-and-fin Heat Exchanger in Automotive Heat Pump System

目前车用空调冷凝器均为平行流冷凝器，作为热泵蒸发器时易结霜，且化霜时排水不畅。而圆管翅片换热器换热性能较差，难以满足结构布置要求。开发了135管径的小管径换热器，与平行流换热器进行了性能对比测试。结果表明：采用小管径管片式换热器时，制冷模式下COP提高了17．4％--23．7％，热泵模式下COP提高12．6％--35．8％，且在热泵模式下可降低压缩机排气温度15—28℃。小管径管片式换热器在电动汽车热泵系统应用前景广阔。

The parallel flow microchannel （PFM） heat exchanger is widely used in automotive air conditioning system, but it has the disadvantage of easy-frost and difficult in water-drain in defrost. The traditional tube and fin heat exchanger can overcome the frost and defrost problem but has low efficiency. In this paper a O5 tube and fin heat exchanger is developed for the automotive heat pump. Performances of small diameter tube-and-fin heat exchanger and PFM heat exchanger are compared based on benchmark test. Results show that the system with small diameter tube-and-fin heat exchanger has 17.4%-23.7% higher COP in air conditioning mode, 12.6%-35.8% higher COP and 15-28℃ lower compressor discharge temperature in heat pump mode, which indicates that small diameter tube-and-fin heat exchanger is a promising solution to the automotive heat pump system of electric vehicle.