Research On Energy Efficiency Improvement Of Energy Supply System For Composite Energy Buildings

The energy consumption of building energy supply system is an important part of building energy consumption in China,and it is also the focus of building energy conservation.Compared with conventional single-energy building energy supply systems,composite energy building energy systems can combine multiple forms of energy such as electricity,natural gas,solar energy,shallow geothermal energy and wind energy,not only using renewable energy,but also improving Energy efficiency can ultimately achieve energy conservation and emission reduction and environmental protection.In this paper,the composite energy building energy supply system is the main research object.Firstly,the principle of cold heat source equipment in the building energy supply system is expounded,and then the performance influencing factors are investigated.Then the ground tube heat transfer is carried out in the experimental platform system.The performance of the direct-fired lithium bromide absorption type cold(warm)water unit under two cooling modes of the cooling unit and the cooling tower are tested to obtain the performance parameters of the unit;then the composite energy building energy supply system and conventional energy are designed and built in the TRNSYS simulation platform.Building energy supply system,and formulate corresponding operation strategies for it;finally,through specific cases,energy supply from composite energy buildings in the form of building energy supply system,primary energy utilization,system energy efficiency,energy utilization and operation strategy The system performs the analysis.In the process of designing the energy supply system of composite energy buildings,this paper proposes a detailed design idea of the energy supply system for composite energy buildings.From the elements that need to be considered to the final determination system,a complete and clear process is given,and at the same time,for the composite energy building.In the system,the problem of soil cold accumulation in the soil source heat pump subsystem under long-term operating conditions is to use solar energy for heat storage in the summer and winter transition season,and propose a solar collector area based on soil heat balance.The matching method is to determine the solar collector area Ac by simulating the soil heat loss difference over the whole year,the average daily heat per unit area of the solar collector and the expected heat storage days,and the absolute value of the soil average temperature offset is less than 1%.Judging basis,Ac increased or decreased by 10% to continuously adjust the area of the new solar collector,and finally find the best matching area.The concrete energy building energy supply system proposed in this paper is analyzed through specific cases,and compared with the conventional building energy supply system(electrically driven chiller-gas boiler system).The results show that in terms of system form,its driving energy use is more consistent.In actual conditions,it plays the role of shifting peaks and valleys during the summer peak season and the peak season of winter use;in terms of primary energy utilization,its primary energy utilization rate is increased by 29%;in terms of system energy efficiency,the annual energy efficiency ratio of the system Increased by110%;in terms of energy use,its renewable energy utilization is feasible,and the renewable energy utilization in the heating season is 419 MW·h.The operational strategy of the building energy supply system is crucial to it.The operational strategy 1 and the operational strategy 2 developed for the composite energy building energy supply system proposed in this paper are analyzed through specific cases.The results show that during the ten-year operation period Through the seasonal heat storage in the operation strategy 2,the heat balance of the soil around the buried heat exchanger is ensured,and the operation strategy 2 is compared with the operation strategy 1,the average heating COP of the heat pump unit is increased by 5%,and the average cooling COP is increased.12%.