为提高跨临界CO2水-水热泵系统的效率,根据已有实验台建立系统仿真模型,分别进行实验测试和数值模拟,通过实验数据验证仿真模型的准确性。基于制取热水的目的,模拟分析运行参数对系统性能的影响,结果表明：增大过热度可提高性能系数（COP）,用户侧供水温度平均提高11.3 ℃;随着高压压力的增大,用户侧供水温度升高,存在最优高压压力使COP最大;增大冷冻水的流量和升高进口温度,系统的制热效率可提高约40%,但用户侧供水温度变化不大。根据实验及仿真结果,设计太阳能辅助跨临界CO2热泵双蒸发器系统,可实现3种不同运行模式,能够升高冷冻水进口温度、增大系统效率。与电加热锅炉和燃气锅炉进行经济性比较,太阳能热泵分别在第5年和第7年与上述两种加热方式的总投资持平,其运行20 a的总投资分别比燃气锅炉和电加热锅炉节约39%和49%,具有明显的经济优势和实用推广价值。
Abstract
In order to improve the efficiency of the transcritical CO2 water-water heat pump system, a system simulation model was established according to the existing experimental bench, and experimental tests and numerical simulations were carried out respectively, and the accuracy of the simulation model was verified by experimental data. Based on the purpose of producing hot water, the influence of operating parameters on system performance is simulated and analyzed, and the results show that increasing the superheat can increase Coefficient of Performance （COP）, and the water supply temperature at the user side increases by an average of 11.3℃; with the increase of high pressure, the water supply temperature at the user side increases, and the COP is maximized by an optimal high pressure; increasing the flow rate and inlet temperature of chilled water, the heating efficiency of the system can be increased by about 40%, but the water supply temperature at the user side does not change much. According to the experimental and simulation results, a solar-assisted transcritical CO2 heat pump dual evaporator system is designed, which can realize three different operation modes, which can improve the chilled water inlet temperature and increase the system efficiency. Compared with electric heating boilers and gas boilers, the total investment of solar heat pumps is same as the total investment of the above two heating methods in the 5th and 7th years, respectively. Its total investment in 20 years of operation is 39% and 49% less than gas boilers and electric heating boilers, respectively, which has obvious economic advantages and practical promotion value.
关键词
太阳能 /
CO2热泵 /
系统性能 /
跨临界 /
实验测试 /
仿真模拟
Key words
solar energy /
CO2 heat pump /
system performance /
transcritical /
experimental testing /
analogue simulation
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基金
天津市科技特派员项目（22YDTPJC00020）; 天津市教委项目（2019KJ113）
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