相变蓄热电采暖沼气池蓄热结构优化

Heat storage structure optimization of phase change storage thermoelectric heating digester

针对我国北方寒冷天气条件下沼气池产气效率低下的问题,设计了一种结合太阳能的相变蓄热电采暖沼气池结构。该结构相较于普通沼气池壁增加了1层相变蓄热层,该层由连续的蓄热单元结构组成。蓄热单元结构内封装相变材料(phase change materials,PCM)和热源,从而提高了沼气池壁增温效果。为提高蓄热效率,减少蓄热死区,对蓄热单元内直管热源进行结构优化,在热源上增加翅片以强化换热。利用Fluent软件对不同翅片结构热源的蓄热层进行内部温度场仿真模拟,分析其蓄热过程,得出最优的相变蓄热层结构,从而有效提高了沼气池蓄热效率。

Aiming at the low gas production efficiency of biogas digester in cold weather in north China,a phase change thermal storage electric heating biogas digester structure combined with solar energy was designed.Compared with ordinary biogas digester wall,a phase change heat storage layer was added in this structure,which was composed of continuous heat storage unit structure.Phase change materials(PCM)and heat source were encapsulated in the heat storage unit structure,which improved the heating effect of biogas digester wall.In order to improve the heat storage efficiency and reduce the dead zone of heat storage,the structure of straight tube heat source in the heat storage unit was optimized,and fins were added on the heat source to enhance the heat transfer.Fluent software was used to simulate the internal temperature field of the heat storage layer of different fin structure heat sources,analyze the heat storage process,and obtain the optimal phase change heat storage layer structure,so as to effectively improve the heat storage efficiency of biogas digester.