钾石盐太阳池集热和储热性能研究

Study on the heat collection and heat storage performance of sylvite solar pond

为了优化钾石盐太阳池的集热和储热性能,采用控制变量法,分析了光照时间,下对流层厚度(12、17、22 cm)以及盐梯度层厚度(9、14、19 cm)对下对流层温度、集热量、储热量和热效率的影响。结果表明:每天光照时间越长,下对流层温度越高,最高达到55.7℃;照射8 h集热量最高达933.68 kJ/h,照射12 h集热量最高达1137.39 kJ/h,照射24 h集热量最高达1595.74 kJ/h;每天光照时间越长,热效率、集热量、储热量上升或下降的速度越快,直到稳定时每天的集热量降到最小,说明对一定结构、一定环境下运行的太阳池存在上限温度;下对流层厚度越厚稳定时储热量越大,运行稳定后,下对流层厚度为22 cm的太阳池平均储热量是17 cm的1.13倍,是12 cm的1.75倍;盐梯度层厚度分别为9、14、19 cm时,所达到的最高储热量分别为3021.72、3140.55、2665.23 kJ,说明盐梯度层存在一个适宜的厚度。研究结果得出太阳池上对流层,非对流层和下对流层合适的占比分别为10%、35%和55%。

In order to optimize the performance of heat collection and heat storage of salt solar pond,this paper analyses the effects of illumination time,the thickness of Lower Convective Zone(12,17 and 22 cm)and of Non-Convective Zone(9,14 and 19 cm)on the temperature,heat collection,heat storage and thermal efficiency of salt solar pond by using control variable method.The results show that the longer the daily illumination time is,the higher the temperature of Lower Convective Zone is with the highest temperature of 55.7℃;the highest heat collection is 933.68 kJ/h for 8 h,1137.39 kJ/h for 12 h and 1595.74 kJ/h for 24 h.The longer the daily illumination time is,the faster the thermal efficiency,heat collection and heat storage increase or decrease until the daily heat collection decreases to the minimum when it is stable.This indicates that there is an upper limit temperature for the solar pond with certain structure and certain environment;the thicker the Lower Convective Zone is,the greater the heat storage capacity will be.The average heat storage of solar pond with the thickness of Lower Convective Zone of 22 cm is 1.13 times of that of the Lower Convective Zone of 17 cm and 1.75 times of that of 12 cm when the operation is stable;when the thickness of Non-Convective Zone is 9 cm,14 cm and 19 cm,the maximum heat storage is 3021.72 kJ,3140.55 kJ and 2665.23 kJ respectively,which indicates that there is a suitable thickness of Non-Convective Zone.It can be concluded that the appropriate ratios of Upper Convective Zone,Non-Convective Zone and Lower Convective Zone are 10%,35%and 55%respectively.