内置隔板开孔方式对太阳能蓄热水箱热分层的影响

Effect of obstacles with different opening means on thermal stratification in hot water storage tanks

为研究具有内置隔板的太阳能蓄热水箱隔板开孔尺寸及位置对其内部热分层效果的影响,对9种隔板开孔位置的太阳能蓄热水箱内温度场进行了数值分析,结果显示:在相同的流动参数及开孔面积条件下,隔板中心开1个圆孔的水箱热分层效果最好。对于多开孔的水箱,开孔位置对水箱内热分层影响不大,但对蓄热量影响显著。对于隔板中心开1个圆孔的水箱,在不同流动参数条件下,冷、热水出口温差随着冷水入口流速的增大呈先增后减的趋势,当冷水入口流速大于0.9 m/s时,减弱了热分层的稳定性。

The solar hot water storage tank is one of the important equipment of the solar energy application system.At present,the research on the performance of the hot water storage tank mainly focuses on the position and shape of the inlet pipe,the flow parameters,the position and geometry of the obstacle in the water tank.There is no report on the influence of the position and size of the opening of obstacles on the thermal stratification in the solar hot water storage tank.This study aims to evaluate the effect of 9 different positions of the opening of obstacles on thermal stratification and to obtain the optimal structure of the solar hot water storage tank and its optimum operating parameters.The results indicate that the tank with one circular opening in the center of the obstacle provides the optimum thermal stratification under the same flow parameters and opening area.For the tanks with multiple openings,the opening position has little effect on thermal stratification in the tank,but a significant effect on thermal energy storage.For the tank with one circular opening in the center of the obstacle,the temperature difference between the hot and cold water outlets increases first and then decreases with the increase of cold water inlet velocity under different flow parameters.When the cold water inlet velocity is greater than 0.9 m?s-1,it will weaken the stability of thermal stratification.