【摘要】 相较于单级相变热能存储系统,多级相变储能具有更快的储能效率。为进一步提高储能元件的热质传递速率,本文利用膨胀石墨对相变材料进行传热强化,组建了二级相变储能元件,并研究了Re数、进口温度等对储能元件传热效率的影响规律。结果表明,随着Re数增加,管道进出口温度差降低,但其吸收的热量随着Re数的增大而增大,当Re数为375.6时,流体释放的热量最多,比Re数为66.8时多了5.1%。除此之外,将进口温度从50℃增加至80℃,流体释放热量增加1.6倍。更多还原

【Abstract】 Compared with the one-stage phase change energy storage, the multi-stages phase change energy storage possess higher energy storage efficiency. In order to enhance the storage performance of thermal energy storage unit, the expanded graphite has been used to form the composite phase change material(PCM), which is applied as the energy storage medium of two-stages phase change storage unit. The effects of Reynolds number and inlet temperature are investigated. The results show that with the increase of Reynolds number, the temperature difference between inlet and outlet drops down, proving the heat transferred from fluid to PCM increases. When the Reynolds number is 375.6, the heat transferred from fluid to PCM is the maximum, and increases by 5.1% compared with Re=66.8 Besides, when the inlet temperature rises from 50℃ to 80℃, the heat transferred has increased 1.6 times.更多还原