Thermal Performance Of Experimental Study On Over-ground Household Biogas Production System Heated By Solar Energy

In cold northern areas in China, the winter temperature is low, gas production rate are greatly influenced by the temperature, the yield is low, sometimes it appears that gas dose not produce, even fermentation tank. Traditional pool is buried in the ground, it makes some problems, such as discharging difficulties and low gas rate.This has restricted the promotion of biogas fermentation. To solve above problems,design a set of home use solar biogas fermentation system on the ground.The system is simple and convenient and it has good heat preservation performance.At first,based on the weather of Huhehaote citiy conditions, design biogas fermentation system in theory. Calculated the volume of pool which can offer the for five people.when the system running in winter with the fermentation temperature30,calculated the pool’s total heat load,the matching of solar collector area and the area of the heat exchange enery.By using the method of numerical simulation optimized the heat exchange coil.Simulate the heat exchanger of the coil under gravity pool by Fulent software.The results show that the segmentation and encrypted coil heating speed than other. Then bulid the biogas fermentation system test bench and make the heating digester simulation experimental verification. It show that the two results are basically consistent, similar change trend. Solid simulation result can be trusted. It provides a reliable numerical simulation method for the heat exchanger optimizing.Put the fermentation system device in winter environment to experimented,through the test and analysis system temperature change in the process.it is concluded that constant stage within two temperature fluctuations in sun day. The biogas fermentation temperature fluctuations not be too big. In two consecutive days cloudy conditions, pool temperature is falling, but it also in two temperature drop range in a day, it does not cause too big effect to the gas prducing. So as long as you don’t meet continuous cloudy weather or extreme weather, molten material temperature will not change many.it can make the fermentation temperature that stable in a certain range.The heating effect of the fermentation system and the heat preservation effect is good.Also it has the strong resistance of environmental interference. This system can ensure the normal operation of biogas fermentation in the winter, if you want to make the system run in a more stable temperature conditions, it should be increase heat preservation measures or other auxiliary heating when in the bad environment.