Research On Regional Multi-generation System Based On Complementary Geothermal And Solar Energy

In the energy structure of our country,we rely too much on the three fossil energy sources,which aggravates the contradiction between environment and economy.In response to the concept of "green water and green mountains are golden mountains and silver mountains",the reform of energy structure is imperative.Geothermal energy and solar energy are co nsidered to be clean,low-carbon,widely distributed,resource rich,safe and high-quality renewable energy.Therefore,this paper combines geothermal energy with solar energy,and proposes a combined cooling,heating and power system based on the compleme ntary of geothermal energy and solar energy,which provides some new ideas for promoting the rational conversion of energy structure in China.Firstly,based on the principle of energy cascade utilization,the regional multi cogeneration system with complementary geothermal energy and solar energy is integrated.In the system,solar energy is used as an external heat source to heat the extracted geothermal water,which can improve the value of geothermal water.After heating,the geothermal water will realize the polygeneration of cold,heat and electricity through different components.According to the different working conditions of users,different operation strategies are adopted to adjust the output ratio of the system,so as to realize the demand of pe ak cooling / heating load of users.Then,the thermodynamic performance of the CCHP system with complementary geothermal energy and solar energy is analyzed.Based on the first law and the second law of thermodynamics,the energy loss,exergy loss,energy flow and exergy flow of the whole system and its components under the design condition are analyzed.At the same time,the operation mode adjustment and overall thermodynamic performance change of the cogeneration system caused by the change of heat source(geothermal water temperature change and solar radiation intensity change)in the process of operation under the design conditions are considered.Finally,the economic analysis and life cycle assessment of the CCHP system with complementary geothermal energy and solar energy are carried out.In the economic analysis,this paper applies the cost allocation method of CCHP system based on energy grade to calculate the product cost of the system,and studies the unit cost of the output products of the CCHP system.In the life cycle assessment,through the analysis of system production,operation,maintenance and disposal,this paper reveals the impact of different stages of the cogeneration system on global warming,ozone layer destruction,human toxicity,acidification and eutrophication.