Research On Optimal Design And Uncertain Operating Of Combined Cooling Heating And Power System With Synergy Of Multiple Energy Sources

The capacity ratio and operation mode of the combined cooling heating and power system with synergy of multiple energy sources is one of the important factors that determine the quality of its comprehensive performance.This paper studied on the optimal configuration and uncertain operation problem of a gas based combined cooling heating and power system with synergy of multiple renewable energy sources.It provides reference for the project planning,design and operation of the system.Firstly,as the triple-supply system with synergy of multiple energy sources involves many basic energy systems,the optimal configuration problem belongs to a multi-system coupling and multi-objective optimization problem.Therefore,the superstructure method and multi-objective optimization theory are applied in this paper.At the same time,in order to ensure that the model is more comfirmed to the practical requirements,this paper respectively constructed the mathematical models of five typical triple-supply systems(CCHP+GSHP,CCHP+ST,CCHP+PV,CCHP+PVCU,CCHP+PVCU+GSHP)with synergy of multiple energy sources,which based on the thermodynamic characteristics model of the basic energy system under hourly operating conditions.A hybrid operation strategy is used to determine hourly,and the Hookjef-Particle Swarm Optimization(HJ-PSO)algorithm is used to solve the global optimization problem.Then the optimal capacity matching scheme of five typical multi-energy cooperative triple supply systems is obtained.Secondly,according to the above results of multi-objective optimization,the optimal operation of triple supply system with synergy of multiple energy sources under uncertain conditions is studied.The uncertain parameters such as energy demand,renewable energy supply,energy price and operating cost of the system are input as random variables at the first.And then combining with interval two-stage stochastic programming method,an energy management model of triple supply system with synergy of multiple energy sources under uncertain conditions is established,and the hourly load analysis of typical day is carried out under different seasons and different energy demand(low,medium and high).The optimal economic operation strategy of typical day in uncertain environment is obtained finally.The above theoretical methods and research routes are used to analyze and study the cases of office and commercial buildings in Beijing in this paper,and then obtained the following conclusions:1)The results of the multi-objective optimization analysis of five typical triplesupply system with synergy of multiple energy sources for office and commercial buildings in Beijing show that:(1)In terms of optimal configuration,for a system of CCHP+GSHP,he proportion of geothermal energy is not as large as the better.The rated refrigerating capacity and the rated heating capacity should be calculated by 20%~30% of the regional cooling capacity or heat supply(taking a smaller value).The rated capacity of a triplex internal combustion engine should be based on 10%~15% of the maximum demand.For the three typical coupling systems of triple-supply and solar energy,the integrated performance of triplesupply and photovoltaic power generation system is optimal.Photovoltaic power generation system should be used first and fully for triple-supply,solar and ground source heat pump coupling systems.(2)In terms of optimizing operational strategies,in order to ensure the best comprehensive performance of the multi-function of the triple-supply system with synergy of multiple energy sources,the following principles should be adopted in the hourly operation strategy of each typical coupled system: CCHP+GSHP system should be operated follow the rule of “following the thermal load” from January to March in heating season,and be operated follow the rule of “following the electric load” at other times.In the heating season from the middle of February to the middle of March,the coupling system of triple-supply and solar energy should follows the rule of “following the electric load”,and be operated follow the rule of “following the thermal load” at other times.Triple-supply coupled solar energy and ground source heat pump coupling system should follows the rule of “following the electric load”.(3)In terms of comparison of multi-objective optimization values,the energy allocation strategy of the triple-supply system with synergy of multiple energy sources should be as follows: with regard to the utilization of solar energy,the system of photovoltaic power generation is preferred,followed by the integrated system of photovoltaic and photothermal,and the last is the photothermal system.In terms of multi energy allocation,the solar system coupled with the triple-supply system is preferred,followed by the CCHP+PVCU+GSHP system,and the last is the CCHP+GSHP system.2)The optimal economic operation strategy of the triple-supply system with synergy of multiple energy sources for office and commercial buildings in Beijing under uncertain environment is as follows:The solar energy resources should be used preferentially and output with maximum power in different seasons and different energy demand.The triple-supply energy should be operated with rated power in ensuring the start-up rate.Conventional energy sources should undertake peak shaving in high load periods during the day and guarantee operation in low load periods at night.This paper provides effective methods for the energy utilization strategy and the optimization configuration of the combined cooling heating and power system with synergy of multiple energy sources.It also provides effective methods for optimal economic operation of the system of a typical day under uncertain conditions.