高径比对空气源热泵缓冲水箱温度分层效果的影响研究

Research on Influence of Height-diameter Ratio on the Temperature Stratification Effect of Air Source Heat Pump Buffer Water Tank

缓冲水箱温度分层有利于增加热泵换热器的换热温差,提高换热效率。本文通过试验方法验证空气源热泵缓冲水箱内部的温度分层现象,通过对比试验和数值模拟的温度值发现误差率<3%,证实了数值模拟的可靠性;为寻找最佳温度分层的缓冲水箱外形尺寸,通过模拟不同体积的水箱在不同高径比下的无量纲?ζ发现,水箱体积在400L以下时,高径比为5时水箱的温度分层程度最好,在不低于400L时,高径比到4时就可以达到很好的分层效果。经计算在分层状况下的缓冲水箱可以提高热泵换热器换热效率5.27%。

The temperature stratification of the buffer water tank is beneficial to increase the heat transfer temperature difference of heat pump heat exchanger and improve the heat transfer efficiency.The temperature stratification in the air source heat pump buffer tank is verified by the experimental method,It is found that the error rate is less than 3% by the contrast experiment and the numerical simulation,which proved the credibility of simulation. To find the shape size of the buffer tank for optimum temperature stratification,Through the simulation of different water tank volume in different ratio of height to diameter of the dimensionless exergyζfound that when the volume of water tank is below 400 L,the degree of temperature stratification is the best when the ratio of height to diameter is 5,when the height ratio is up to 4,a good stratification effect can be achieved at less than 400 L. By calculation,the buffer tank under the condition of stratification can increase the heat transfer efficiency of heat pump heat exchanger by 5.27%.