System Architecture And Technolical & Economic Evaluation On Central Heating Network Coupled With Solar Energy

In order to accelerate the realization of the "Carbon peak carbon neutral" goal,renewable energy is greatly encouraged in the heating industry.Solar energy is a typical and potential renewable energy with wide distribution.Beijing,a typical northern heating city,is rich in solar energy resources,and the urban heating network is relatively mature.This paper explores away to couple with solar energyand urban heating network.This paper proposes a centralized heat supply network system framework with solar heating based on the solar heating pilot project of the National Science and Technology Communication Center,whose the technical and economic performance is also discussed.A simulation model is built with the TRNSYS software,where the boundary conditions is provided by the meteorological software,such as meteorological parameters and solar radiation intensity.The simulation model is used to analyze the heating capacity,operation time and efficiency under various solar input,and then a technical configuration is discussed and suggested.The hourly output temperature curve shows that the maximum output temperature of the collector is 75 ℃,the temperature of the heat storage tank is basically maintained at 50 ℃～56 ℃,which can meet the normal heating demand.According to the TRNSYS simulating,the whole heating season is estimated as 127 days,totaling 3048 hours.As the heat load by the solar collector increases from 25% to 60%,the operation time of the heat storage tank increases from 2813 hours to 3038 hours,the operation time of the municipal heating system ranges from 923 hours to 885 hours,and the operation time of the solar collector system ranges from 706 hours to 712 hours.The low-temperature water in the heat storage tank is heated to 48 ℃ through the primary return water of heat supply,which ensures that the solar heat collection system can effectively increase the outlet temperature in winter.The proportion of heat supply in the primary water supply system can be reduced to 34%～37%,which has a good energy saving potential.Compared with the conventional heating system,the centralized heating network system coupled with solar heating has positive advantages in economic benefits,energy saving efficiency and environmental benefits.The initial investment and the total annual heating cost are relatively low at a solar energy load ratio of 25%-30%,and the investment recovery cycle is about 5 years.The lowest annual total cost per unit of heating is about 91.10 yuan / GJ,the primary energy utilization rate is between0.94-1.08,and the green energy utilization rate is up to 37.37 %.This study is expected to provide useful reference for the construction and operation of centralized heating system coupled with solar energy.