摘要
基于R134a压焓图和Cleland计算模型,分析了低温环境下运行参数对两级压缩一次节流中间不完全冷却空气源热泵系统性能的影响。结果表明:冷凝温度和蒸发温度是影响系统COP的主要因素,且蒸发温度影响更大;冷凝器出口处过冷度对系统COP和低压级制冷剂流量的影响较小,高压级制冷剂流量随过冷度的增加而减少,且减少幅度随蒸发温度和冷凝温度的升高而逐渐增大;系统蒸发器出口处过热度几乎不影响COP;高压级压缩机的排气温度随蒸发器出口处的过热度增加而增大;而高、低压级制冷剂流量随蒸发器出口处过热度的增加而降低,且降低幅度随蒸发温度的降低逐渐降低,但基本不受冷凝温度的影响。
Based on the pressure enthalpy diagram of R134 a and the Cleland calculation model,the effect of operating parameters on the performance of two-stage-primary-throttle-incomplete-cooling-air source heat pump system in low temperature environment is analyzed. The results show that both condensing temperature and evaporating temperature are the main factors influencing the system COP,among them,the evaporation temperature has great impact. Also,the sub-cooling degree at the condenser outlet slightly impacts both the COP and the refrigerant flow rate at low pressure level,and the refrigerant flow rate at high pressure level decreases with the growth of the sub-cooling degree,and the decay rate increases gradually with the increasing evaporation and condensation temperatures. Furthermore,the COP seldom varies with the super-heat degree at the outlet of evaporator,and the condenser exhaust temperature at high pressure level increases with the rising super-heat degree at the outlet of evaporator. Furthermore,the refrigerant flow rate at low and high pressure level both reduces with the increasing super-heat degree at the outlet of evaporator,meanwhile,the gradient decreases with the reducing evaporation temperature,yet they are not influenced by the condensation temperature.
出处
《流体机械》
CSCD
北大核心
2017年第3期56-60,74,共6页
Fluid Machinery
基金
国家自然科学基金资助项目(51308077)
江苏省高校自然科学基金资助项目(13KJB560001)
关键词
空气源热泵
两级压缩
过热度
过冷度
COP
air-source heat pump
two-stage compression
super-heat degree
sub-cooling degree
COP
