沼气池搅拌的CFD模拟及温度场验证

CFD simulation and temperature field validation of biogas digester mixing

为了对底侧入式搅拌的沼气发酵池内的流场进行研究,该文采用计算流体力学方法,以上海市崇明县某示范工程的主体沼气发酵池(69.3m3)为对象,对流场和温场进行计算模拟,并通过温度测量来验证温度数值模拟的可靠性,从而间接验证流场数据准确性。通过温度场的模拟和实测数据对比,整体温场模拟和实测数据在0.05水平下无显著差异;通过流场模拟和工程运行的观察,都反映此发酵池中设计的底侧入式搅拌不能充分实现发酵池的搅拌。但模型在相关设定上仍有与实际不符之处,模型仍有待完善。

The characteristics of the flow field in anaerobic digester with the bottom side entering agitator was studied by computational fluid dynamics（CFD）.With data collected from a main methane fermentation tank（69.3 m^3） of demonstration project in Shanghai Chongming County,numerical simulation for the temperature and flow field was performed.The reliability of the temperature field simulation was certificated with the temperature measurements,which indirectly verified the flow field data.Temperature simulation results were compared with experiment data,and the statistical analysis showed no significant difference under 0.05 level.The bottom side entering agitator can not form the full loop in the fermentation tank according to the numerical simulation and actual observation.However,there are some discrepancies between the model settings and the actual situation,the model still needs to be improved.