相变板储热水箱充/放热速率及经济性分析

Charging/discharging rates and economic analysis of a PCM plate heat storage tank

中文关键词: 相变材料板  储热水箱  充/放热性能  经济性分析

英文关键词: PCM  plate, heat  storage tank, charging  and discharging  performance, economic  analysis

中文摘要:

      本文将相变材料板按照一定结构排列在水箱中，制成相变储热水箱。实验研究了进口流量和进水温度对相变板储热水箱充热和放热性能的影响，监测了相变材料的温度变化情况，采用了雷诺数（Reynolds,Re）和史蒂芬数（Stefan，Ste）分析储热水箱的充/放热速率，并进一步对相变储热装置进行了经济性分析。结果表明：设置不同的进口水温和流量，可调控充/放热速率，满足不同用户侧的需求。在充热过程中，当Ste数为0.292时，Re数从33增加到62.4，平均充热功率增大59.23%。Re数为62.4时，Ste数从0.216增加到0.292，平均充热功率增大34.44%。不同位置的相变材料温度基本一致。在放热过程中，储热水箱内Re数和Ste数的减小均能延长供热时长。Ste数为0.521时，Re数从62.4减小到33，有效放热时间增加了135.65%。相变材料在高度方向温度变化有明显的差异。经济性分析表明，在广州市和深圳市采用空气源热泵结合相变储热装置提供热水能够在4年内回收成本，可为相变储热装置在生活热水中应用提供参考。

英文摘要:

      In this paper, a heat storage water tank is constructed by arranging the phase change material (PCM) plates with a certain layout. Effects of the inlet flow rates and inlet temperatures on the charging and discharging performance of the heat storage tank device are studied experimentally with an attention paid to the variations of PCM temperature. Reynolds number (Re) and Stefan number (Ste) were used to analyze the charging/releasing rate of the heat storage tank, and economic analyses of the heat storage device are further carried out. Results show that the charging/discharging rate can be regulated by setting different inlet water temperatures and flow rates in order to meet the needs of the users. During charging process, when Ste is 0.292, Re increases from 33 to 62.4, and the average charging power is increased by 59.23%. When Re is 62.4 and Ste increases from 0.216 to 0.292, the average charging power increases by 34.44%. The PCM temperatures at different positions are generally the same. Regarding the discharging process, the discharging time can be prolonged by reducing Re and Ste. When Ste is 0.521 and Re decreases from 62.4 to 33, the effective discharging time increases by 135.65%. The PCM temperatures are significantly differentiated vertically. The economic analysis shows that the cost of PCM heat storage device combined with air source heat pump can be recovered within 4 years in Guangzhou and Shenzhen, which can provide a reference for the application of the PCM heat storage device in domestic hot water.