| In the northern part of China,the winter is cold and long,the ambient temperature is low,and even the problem of frozen cracking biogas digesters may occur.At the same time,the increase of the ambient temperature in summer will cause the problem of waste of heat.Therefore,the gas production rate of biogas is low and the comprehensive benefits of the project are poor.At present,most of the heating methods of biogas digester are mainly used for household biogas digester.The research on heating and insulation methods of biogas digesters for large and medium-sized biogas projects in cold regions is less and the effect is not ideal?At the same time,considering the livestock manure as biogas fermentation raw material,the fermented biogas manure can be used in farmland fertilizer,planting and aquaculture,making the breeding industry form a virtuous cycle and realize zero emission of pollution,which will hopefully solve the problem of environmental pollution caused by ineffective treatment of a large number of livestock manure.In order to solve the above problems,this paper establishes a solar-power waste heat heating biogas digester system,and takes the livestock manure biogas project as the background,takes the solar-power waste heat heating biogas digester system as the research object,takes the numerical simulation analysis as the main,based on the theoretical analysis of the system,uses TRNSYS platform to build.The system dynamic simulation model is established,and a new system operation plan is proposed.Then the operation of the system in the northern region is simulated and analyzed,and the thermodynamic,economic and environmental benefits of the system are further analyzed and evaluated.The results show that the system can achieve efficient utilization of heat energy,and the environmental benefits are significant.Firstly,the performance and influencing factors of solar collector,the basic principle and influencing factors of biogas production and the resource conditions of biomass livestock excrement and urine in China are analyzed and studied,which lays a theoretical foundation for the system design,establishes the physical model of the system and the mathematical calculation model of the main equipment in the system,and makes a subsystem of the system.The design ensures the reliability,stability and accuracy of the systemSecondly,on the TRNSYS software platform,the dynamic simulation model of the solar-power waste heat heating biogas digester system is constructed and verified The design idea of a new system operation scheme is put forward:in cold winter weather,the system meets the heat load of anaerobic fermentation at middle temperature in biogas digester,in hot summer weather,the system meets the heat load of anaerobic fermentation at high temperature in biogas digester,and solves the problem of excessive heat generated by heat supply in summer due to the satisfaction of heat supply in winnter.Thus the whole year is divided into five stages:normal temperature-medium temperature operation stage(only the first start-up),medium temperature fermentation operation stage,medium temperature-high temperature operation stage,high temperature fermentation operation stage and high temperature-medium temperature operation stage,and the operation parameters of each stage of the system are determinedFinally,six northern cities(Nanyang,Jinan,Zhengzhou,Beijing,Lanzhou and Shenyang)were selected to simulate the operation of the system in different stages,and the thermodynamic,economic and environmental benefits of the system were evaluated.At the same time,the influence of biogas pool size and volumetric gas production rate on biogas engineering of heating system is also analyzedThe research results of this paper will be of certain reference value to the design and related research and application of the system in the northern cold area,and also lay a preliminary foundation for the follow-up research and application of the system. |
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