Research On Integrated District Energy System Optimization Based On Biomass Gasification Polygeneration

With the depletion of fossil energy,the development of environmentally friendly renewable energy and energy efficiency technologies has become the focus of research.Polygeneration system emerges as a pivotal sustainable solution that may use multiple fossil and renewable energies(i.e.natural gas,coal,biomass)with simultaneous delivery of several outputs(i.e.electricity,heating,cooling,gas and liquid fuels)through diversified energy conversion technologies(including gasification and pyrolysis),in which the chemical processes and power systems are closely integrated and properly designed to enhance energy efficiency,reduce emission and waste,and conserve resources.In this background,the biomass poly generation integrated energy system(BPIES)system has the advantage of energy cascade utilization and multi-energy complementation,as well as low fuel price and high value-added chemical products simultaneously,which is considered as the most effective clean energy technology for biomass utilization.However,the current research on such systems is limited to specific conversion technologies such as biomass gasification and combustion that rarely involves the analysis of energy demand as well as the design and operation optimization of integrated energy systems.Therefore,in order to promote the integrated modeling and optimization research of BPIES system,the main works of this paper are as followsFirstly,based on the superstructure modeling method,a detailed mechanism model is established for the gasification module,CHP module and chemical synthesis module of the BPIES system.The mathematical model of auxiliary module such as the heating technology(condensing boiler),cooling technology(electric chiller,absorption chiller,etc.)and renewable energy technology(ground source heat pump,photovoltaic,etc.)is also established based on the operation characteristics.Secondly,the integrated optimization model of BPIES system is built based on the performance characteristics and operation schedule of each submodule.Comprehensive evaluation of the system is carried out from the aspects of economy,environment,technology and energy consumption on the premise of meeting regional energy demand,and the reliability and validity of the model are verified by case studies through energy price sensitivity analysis.Finally,considering the load variation in different regions and types of buildings.four process schemes for biomass polygeneration system taking the gas turbine and steam turbine as the prime mover are proposed according to different ways of waste heat utilization.Besides,the viability of BPIES system in different regions is analyzed Thereby to achieve optimal technology combination,operation strategy and biomass syngas splitting of the BPIES system in application scenarios.