内嵌加热管束反应床Ca(OH)_(2)/CaO热化学储能性能研究

Study on Ca(OH)_(2)/CaO Thermochemical Energy Storage Performance of Reactor With Embedded Heating Tube Bundle

热化学储能在能量密度以及能量的长期存储上较显热储能和潜热储能2种方式具有较大的优势,并且在远距离输送上具有比较小的能量损失。采用热化学储能中的Ca(OH)_(2)/CaO储能体系进行数值研究,旨在探索内嵌加热管束反应床的尺寸以及加热温度与反应床储热性能之间的关系。针对多孔反应床内的储能反应建立一个物化模型,采用数值计算的方法将反应床反应过程中的传热传质过程进行量化分析。以反应床的储能率表征反应床的储热性能并分析不同工况下的反应模式。结果表明内嵌管束加热方式比反应床外壁加热有更高的储热性能,尽管前者的加热面积远小于后者,但与后者相比,其储能率仍提高3.8%左右。另外,研究发现在不同的反应率下反应床尺寸变化对储能率的影响效果不同。对反应床的加热温度变化研究表明,不同的尺寸参数对加热温度的变化敏感程度也是不同的。对于文中反应床,当额定加热温度为863K,半径为120 mm,高650mm时反应床的储能效率达到最高。

Compared with the sensible energy storage and the latent heat energy storage,in terms of energy density and long-term storage of energy,the thermochemical energy storage has great advantages and relatively less energy loss in long-distance transportation.The Ca(OH)_(2)/CaO thermochemical energy storage system was used for the numerical study to explore the effects of the size of the reactor with embedded heating tube bundle and heating temperature on the thermal energy storage performance of the reactor.A physicochemical model was established for the energy storage reaction in a porous reactor,and the heat and mass transfer processes in the reactor were quantitatively analyzed by means of numerical calculation.The thermal storage performances of the reactor and the reaction modes under different conditions were analyzed by using the energy storage rate of the reactor.The results show that the heat storage rate of the reactor with the inner tube bundle heating mode is better than that of the reactor with the outer wall heating mode,and although the heating area of the former is much smaller than that of the latter,compared with the latter,its energy storage rate can still be increased by about 3.8%,In addition,it is found that the effects of the reactor size on the energy storage rate of the reactor are different under different reaction rates.The study on the change of heating temperature of the reactor shows that,the sensitivities of different size parameters to the change of heating temperature are also different.For the reactor in this paper,when the rated heating temperature,the radius and the height of the reactor are 863K,120mm and 650mm,respectively,the energy storage efficiency of the reactor reaches the maximum.