Research On Multi-energy And Complementary Renewable Energy Station System In North China

Under the guidance of the national "two-carbon" strategy,the low-carbon transformation in the field of building energy is imperative.In terms of energy supply for rural buildings,the vast rural areas are rich in renewable energy such as wind energy,solar energy and biomass energy.To promote its application is an important measure to implement the "double carbon" goal and vigorously develop new energy.There are abundant solar energy and biomass resources in the rural areas of North China,and there are sufficient conditions to replace traditional fossil energy with solar energy and biomass energy.But the solar energy as a single heat source heating system running stability is poor,resulting in the system due to the low solar guarantee rate and insufficient energy supply;In the process of biogas anaerobic fermentation,temperature has a significant effect on gas production.In cold North China,the continuous low temperature in winter will lead to the decrease of gas production rate of biogas digester.Under the background of vigorously promoting air source heat pump heating in North China,in order to alleviate the energy supply problems in rural areas of North China in winter,this study proposes to combine solar heating technology with biogas anaerobic fermentation technology,and use air source heat pump as backup heat source to form a renewable energy multi-energy complementary energy station system,so as to solve the technical problems of renewable energy application in rural areas.At the same time,the comprehensive utilization of low-grade renewable energy will be realized to promote the low-carbon transformation of rural energy.Renewable energy multi-energy and complementary energy station system integrates a variety of renewable energy sources.In its operation process,the system performance is not only affected by climate conditions,user’s energy use and other factors,but also the distribution ratio of heat supply and capacity parameters of heat source equipment are important factors.In order to master the variation rule of system operating performance under different heat supply distribution ratio and heat source equipment capacity,this paper conducts research based on experimental test data and combined with system simulation numerical simulation.The main research contents include:(1)Build an experimental platform for renewable energy multi-energy complementary system,and analyze the technical feasibility and actual operation characteristics of the system through actual measurement.(2)The TRNSYS simulation model of the renewable energy multi-energy complementary energy station system was established,the accuracy of the model was verified by the measured data,and the evaluation index of the system operation performance was proposed;Through the simulation calculation of different operating conditions of the system,the influence of different distribution ratio of heat supply and capacity of heat source equipment on the operating performance of the system is analyzed.Through the above research content,the following main conclusions can be drawn:(1)Through the experiment of small renewable multi-energy complementary energy station system,it was determined that during the continuous operation test period of 28 days,the indoor temperature could be kept above 20℃,and the fermentation temperature in the biogas digester was stable between 28 and 30℃,which met the requirements of indoor heating and the fermentation conditions in the biogas digester,proving the technical feasibility of the multi-energy complementary energy station system;(2)The TRNSYS simulation model is established according to the experimental platform of the small energy station system,and the average error between the measured data and the simulated data is less than 5,and the average relative error is less than 10%,indicating a high accuracy of the model.(3)By analyzing the influence of heat distribution ratio and heat source equipment capacity on system performance,it is found that the increase of heat distribution ratio can promote the heat storage of the system;In the heating capacity of the heat source equipment,the increase of the volume of the heat storage tank and the volume of the biogas digester is conducive to improving the operating performance of the system.(4)When the heat distribution ratio is 0.7,the heat storage tank volume and heat collection area ratio is 50L/㎡,the volume of biogas digester is 6m3,the performance of each subsystem and the comprehensive energy efficiency of the energy station system reach a good level.