Optimization Design And Comprehensive Analysis Of The Heating And Cooling Source Scheme Of A Regional Energy Station In A Business District Of Yangzhou

District cooling and heating is eonsidered to be a large-scale system that can utilize renewable energy on a large scale to cope with the regional characteristics of urbanization in recent years,with high efficiency,safety and reliability.Accurate load forecasting in project planning for cooling and heating for a certain area is the basis and premise of system design,and the design of cooling and heating source scheme is the core and difficult point of project planning,The analysis and comprehensive evaluation of the various indicators of the program is an important step before the decision-making of the plan.This paper takes a business district in the western part of Yangzhou New City as tthe research object.The construction load forecasting,cooling and heat source system optimization design and scheme evaluation were carried out in this area.Using DeST software,the detailed modeling and year-round load calculation of 8 buildings in the region were carried out to obtain the load characteristics of various buildings and the whole region.The results show that different load characteristics of different buildings are caused by different parameters of envelope,interior design index,work and rest pattern and operating time of air conditioning.The maximum annual cooling load of the region is 28.58MW,and the corresponding cooling index is 172W/m2.The maximum heat load is 10.972MW,and the corresponding thermal index is 66W/m2.The low load rate(0～25%)accounts for the longest operating period,which is 52%and 77%for the cooling and heating seasons respectively.Among all the buildings,the theater has the largest annual cooling,thermal load and cooling index.The concert hall has the largest thermal index.After analyzing the resource conditions around the region,it is found that water sources of rivers and lakes and natural gas are safe,stable and abundant compared with other energy sources,which are suitable for the project as reliable cold and hot sources.In the combination of cold and heat sources,reasonable application of energy storage technology,heat pump technology and cold,heat and electricity supply technology can bring stable,energy-saving,efficient and clean energy supply mode to the region.Three schemes of ice storage combined with gas boiler,water source heat pump combined water storage and triple supply of cold,heat and electricity are determined as further research objects in this paper.The optimal design of ice storage and water storage system is carried out by calculating the optimal cooling storage rate and adopting the strategy of "partial thermal power generation"for the triple supply system,and the initial investment,operating cost and operating energy consumption of each scheme are obtained.Different evaluation methods are used to analyze and compare the indexes of each scheme.The evaluation results of equivalent uniform annual fee method show that scheme 2 is the most economical.Scheme 3 has the best data in the calculation results of equivalent coal,primary energy utilization and air pollutant emission.Exergy analysis was used to calculate and compare the exergy efficiency of different schemes,and it turns out that exergy efficiency of option 3 is the best thermodynamic economy.Finally,the hierarchical fuzzy comprehensive evaluation method is used to comprehensively evaluate all schemes,ranking by membership degree,scheme 2>scheme 3>scheme 1.According to the principle of maximum membership,the combined water storage energy of water source heat pump is the best scheme of this project.