天然制冷剂R290用于热泵干衣机能效实验研究

Experimental Study on Energy Efficiency of Heat Pump Clothes Dryer with Natural Refrigerant R290

独立式热泵干衣机目前主流制冷剂以HFCs类R134a为主,其全球变暖潜值(GWP)高达1430。天然制冷剂R290属于HCs类制冷剂,GWP小于20。本文基于天然制冷剂R290与R134a的物理和热力学性质对比分析,对独立式热泵干衣机热泵循环系统进行了优化设计和实验研究,最终确定蒸发器采用φ7 mm管径铜管和2.2 mm片距的亲水平片,冷凝器采用φ5 mm管径铜管和1.5 mm片距的非亲水平片,压缩机采用排量为8.1 mL的R290制冷剂压缩机,节流装置采用管径φ1.0 mm和长度820 mm的毛细管。测试结果表明:R290用于独立式热泵干衣机热泵循环系统,在满足国际、国家和欧洲标准中关于A3类制冷剂充注量限制的要求下,即对于A3类制冷剂,若其充注量不大于0.15 kg时,则没有房间体积限制。在R290充注量为0.15 kg时,热泵干衣机能效指标为23.0,可达到欧洲现行干衣机能效等级标准最高等级A+++。

Clothes dryers are widely used in American and European homes;in particular,specific independent heat pump clothes dryers are used in European homes.Independent heat pump dryers feature high efficiency,low power consumption,and clothes protection prop-erties.As a result,they are increasingly being favored by consumers in China.Currently,the mainstream refrigerant used in heat pump dryers is R134a,belonging to the A1 class and featuring low chronic toxicity and zero flammability;additionally,its maximum Global Warming Potential(GWP)is 1430.Meanwhile,natural refrigerant R290 belongs to the A3 class featuring low chronic toxicity;it is flammable and can be explosive,and its GWP is lower than 20.This study is performed based on natural refrigerants R290 and R134a;their physical and thermodynamic properties are compared to optimize the system design of a heat pump clothes dryer.Subsequently,the performance of a heat pump clothes dryer using those refrigerants is analyzed.The final system design features an evaporator withφ7 mm diameter copper tubes and hydrophilic plain fins with a fin spacing of 2.2 mm.The condenser featuresφ5 mm diameter copper tubes and hydrophobic plain fins with a fin spacing of 1.5 mm.An 8.1 mL displacement R290 compressor is used,and the throttling device is a capillary tube withφ1.0 mm diameter and 820 mm length.The results indicate that using R290 in the heat pump system of the clothes dryer satisfies the requirements of international,national,and European standards of the A3 class refrigerant charge limit,implying that if the maximum charge amount of the A3 class refrigerant does not exceed 0.15 kg,the room volume is not restricted.When the R290 charge amount is 0.15 kg,the heat pump dryer energy efficiency index is 23.0,thus achieving the highest level(i.e.,A+++)of the current European energy efficiency standard for clothes dryer.