Research On Optimal Design And Operation Mode Of Solar Energy Heating System

With the rapid development of society,the people's demand for energy consumption is also increasing.The production mode relying only on primary energy can not meet the needs of social development,and it does' t conform to the sustainable development strategy of energy conservation and environmental protection.According to the strategic requirements of the upgrading of energy consumption structure in China,this paper studies the solar district heating system from three layers of system design,engineering applicability and operation adjustment to meet the user's hot water and heating demand,and realize indoor thermal comfort.First,combined with the current situation of solar energy resources in China,the working principle and basic operation mode of the solar district heating system are put forward.Combined with specific engineering cases,the design method of system capacity is given,including the area of solar collector,the volume of heat storage tank and the type selection of water pump.The economic mathematical model of solar district heating system is established,and combined with the case,the optimization of the network structure,the setting of auxiliary heat source and the applicability of the engineering are studied.In this paper,the formulas for calculating the temperature and flow parameters of each node in a one-way circular heating network are derived,and the economic model is used to draw a conclusion that the one-way annular heating network is more economical than the double pipe system.The influence of the area of the solar collector on the annual cost of the system is studied by selecting the electric boiler as the auxiliary heat source,and the higher the solar collector area is,the higher the solar energy guarantee rate is,the more economical the system is.In view of the applicability of the system,the research shows that the Lhasa area is the most suitable for the development of solar energy district heating system,the area of solar heat collector is the smallest under the same heating area.With the increase of the heating area of the system,the annual value per unit area cost of the system gradually decreases and tends to be fixed.The engineering applicability of the system is also affected by various aspects such as land resources,system operation and regulation.In terms of operation adjustment,the optimal operation adjustment method of typical day and heating period in solar energy regional heating system is put forward,combined with a case,the optimal operation adjustment strategy is given.According to the typical day,the design method of water supply flow temperature and water supply flow rate is studied,and five control schemes are given in combination with the relationship between time and demand of load and supply.According to the heating period,combined with the daily outdoor meteorological parameters,the control strategy of the system operation mode was studied,and the long change trend of each model running time was analyzed,and the reference for the actual project operation design was provided.This paper provides ideas for efficient utilization of solar energy resources in China,and provides theoretical support for the study of actual solar energy heating projects.