Experimental Numerical Study Of Biogas Yield In A Wall Immersed Spiral Tube Heater Biogas Plant In Winter

The low temperature environment in winter can greatly reduce the gas production in the biogas digester,in the meantime,it will have a negative effect on the biogas digester itself.Using the internal heater to heat the biogas digester in winter,which can effectively improve the gas production capacity of biogas digester in winter and save energy and living cost.This paper use 8m~3 household biogas digester as the object of study.By studying the change of temperature field and biogas production in different types of heaters,the heater efficiency of biogas digester was further improved.The methane tank heating load in winter,structure and design scheme of immersed spiral tube heater are discussed.The heating transfer coefficient of the heater,the length of the heat exchanger coil,the length of the wall type and the heat exchanger coil of the ground heater have been designed and calculated.The resistance of heater system has been calculated.The experimental system of heated biogas digesters has been improved.The main equipment and materials of the heater have been selected.The wall type,ground type and the combination of different types of heaters have been set.The installation and debugging of on-site heater assembly and testing system were carried out.By analyzing the experiments in different temperature monitoring data,the outdoor temperature of 1.5 m in the underground soil influence and indirect influence on biogas slurry temperature,and the different heater at work biogas slurry temperature field distribution and average temperature rise of biogas slurry have been gotten.It is proved that,although the average temperature of the combined heater is lower than that of three independent heaters,the distribution of the temperature field of the biogas liquid is more uniform and the biogas production is higher.At the same time,some opinions on the operation and maintenance of the biogas pool have been put forward in the condition of the experiment.According to the characteristics of the biogas slurry and the heater,the model of heater heating biogas liquid heater is simplified.By analyzing the simulation results,comparing the simulation and the temperature variation trend of the different monitoring points in the experiment,the reasons for the change of the simulated and experimental data have been found out,and the temperature rising trend of the other monitoring points in the simulation has been proved.The experimental results are basically the same,and the simulated values can be used as references.