供暖用CO2空气源热泵变频运行性能研究

采用压缩机变频、设置回热器与气液分离器辅助加热等技术途径,设计与构建一种供暖用CO2空气源热泵系统。在此基础上,建立响应面模型对供暖用CO2空气源热泵的压缩机运行频率进行优化,以提高供暖用CO2空气源热泵的低温性能。响应曲面法分析结果表明,低温环境下压缩机合理升频运行可有效提高供暖用CO2空气源热泵制热量,虽压缩比增大,但仍能保证压缩机稳定运行。为提高供暖用CO2空气源热泵的性能系数(COP),在低温环境下压缩机可分段变频运行。当环境温度依次为-5、-10及-15℃时,COP最大时对应的压缩机运行频率分别为55、58及60 Hz。

RESEARCH OF VARIABLE FREQUENCY PERFORMANCE OF CO2 AIR SOURCE HEAT PUMP ON HEATING

There are some limitations of CO2 air source heat pump for heating,which are mismatching between heating power and heating load,high return water temperature and low inspiratory pressure.A CO2 air source heat pump system for heating is designed by means of compressor frequency conversion,heat exchanger and gas separator with electric heating.On this basis,through establishing response surface models,the compressor operating frequency of CO2 air source heat pump is optimized to improve the low temperature performance of the heat pump.The results show that,reasonably increasing the frequency of the compressor can effectively improve the heat capacity of CO2 air source heat pump for heating in low temperature environment.Although the compression ratio increasing,the compressor stable operation still can be guaranteed.In order to improve coefficient of performance(COP)of CO2 air source heat pump for heating,compressor in low temperature environment can be segmented frequency operation.When the ambient temperature is-5,-10 and-15℃,the maximum value of COP corresponds to the frequency to be 55,58 and 60 Hz respectively.