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为了研究R134a在螺旋套管冷凝器换热性能及其对热泵运行性能的影响,论文采用实验手段,在以水为冷却介质进行循环加热和直流稳态2种条件下,测试了不同进水流量和入口水温状态时R134a在螺旋套管冷凝器内的换热性能和热泵的运行性能。结果表明:循环加热时,同一进水流量随入口水温的升高,冷凝器总换热量、系统制热量和制热性能系数COP减小,而总换热系数和系统输入功率增大;进水流量从1.19 m3/h增大到2.16 m3/h,入口水温从30℃升高到60℃时,系统输入功率的增大范围为750~900 W,制热量的减小范围为600~750 W,COP的减小范围为2.8~3.2,同时流量2.16 m3/h的总换热量的减小量是流量1.19 m3/h的2.5倍,总换热系数的增大量是流量1.19 m3/h的2倍。直流稳态时,进水流量从0.26 m3/h增大到0.71 m3/h,总换热量和总换热系数分别增加了15%和41%;压缩机的排气功力和系统输入功率分别下降了26%和12%,而吸气功力变化较小。
In order to study the heat transfer performance of R134a and its effect on the performance of heat pump, experiments were carried out to investigate the effect of R134a on the performance of heat pump. The experimental results show that under different conditions of water circulation, And inlet water temperature R134a in the spiral tube condenser heat exchanger performance and heat pump performance. The results show that with the same heating rate, the same influent flow rate increases with inlet water temperature, and the total heat transfer coefficient, heating capacity and heating coefficient COP of the condenser decrease while the total heat transfer coefficient and system input power increase. The water flow increased from 1.19 m3 / h to 2.16 m3 / h. When the inlet water temperature increased from 30 ℃ to 60 ℃, the system input power increased from 750 to 900 W, and the heating capacity decreased from 600 to 750 W and COP decreased from 2.8 to 3.2, while the total heat exchange capacity of 2.16 m3 / h was reduced by 2.5 times of 1.19 m3 / h and the increase of total heat transfer coefficient was 1.19 m3 / h 2 times. DC steady state, influent flow increased from 0.26 m3 / h to 0.71 m3 / h, the total heat exchange and total heat transfer coefficient increased by 15% and 41%; compressor exhaust and system input power, respectively, Decreased by 26% and 12%, while changes in inspiratory skills smaller.