Research On Optimization Design Of Solar Energy-Gas Fired Boiler System For Decentralized Heating

With the development of the society,the environmental deterioration and the energy shortage has become the primary peoblem.The environmental problem in the northern especially in the Jing Jin-Ji region is serious.The heating demand of people in the south cities especially in the Yangtze River areas is gradually expanding.Using pollution-free and renewable energy to provide domestic hot water and heating for the building is the key to solve the problem.In this paper,we proposed a combination system for decentralized heating,which consist of the solar collector,the heat storage tank,gas-fired heating and and hot water combi-boiler.The research on optimization design of this system has been done.First of all,the principle of the solar energy-gas fired boiler system has been determined,the unsteady mathematical model of the heating units and the heat storage tank have been established to calculate the energy provided by each unit.The experiment platform of the the hybrid energy system has been set up.The validity of the model was verified by experiment.Secondly,the optimization design of the system has been done.Taking the annual comprehensive energy efficiency coefficient and the annual total cost as the objective function respectively.The orthogonal experiment method and the mathematical model of the system have been adopted in this paper to calculate the annual comprehensive energy efficiency coefficient the annual total cost and the solar guaranteed rate of the schemes,which differ in the area of the solar collector,the volume of tank,the form and type of the gas-fired boiler and start/stop temperature difference of the solar collector cycle.Then the optimization design of the system in five representative cities in China's five major typical climatic zones has been done.Finally,in the range of the optimization formula of the solar energy-gas fired boiler system,the sensitivity of the factor: the area of the solar collector,the volume of tank,the form and type of the gas-fired boiler and start/stop temperature difference of the solar collector cycle to the annual comprehensive energy efficiency coefficient and the annual total cost were researched.The results of this study can provide a reference for the optimal design and production of solar energy-gas fired boiler system,which made it beneficial to promote and apply this type of system.