Research On Performance And Operation Optimization Of Solar And Water Source Heat Pump Composite Heating System In Alpine Area

Under the goals of carbon peaking and carbon neutrality,energy-saving and environment-friendly renewable energy heating technology is gradually promoted,based on this,this paper proposes a solar energy and water source heat pump composite heating system,based on the residential building in Riya Town,Dingjie County,Shigatse City,Tibet,the building model of Riya Town is constructed by using De ST software,and the load characteristics of the building are analyzed,then based on the TRNSYS software platform,a solar energy and water source heat pump The model of the composite heating system was then established based on the TRNSYS software platform,and the operating characteristics of this heating system applied in the local area were explored from the perspectives of system operation energy consumption and system performance,followed by capacity optimization of the key parameters of the composite heating system,determination of the optimized parameter values,and finally evaluation of the comprehensive benefits of the heating system.Firstly,this paper introduces the building profile of Riya Town,Dingjie County,Shigatse City,Tibet,which has the climate characteristics of an alpine region,and uses De ST software to build a corresponding building model and simulate and analyze the heat load characteristics of the building.The local temperature difference between day and night is large,and the time-by-time heat load index is mainly concentrated between20 and 70 W/m~2,and the maximum time-by-time heat load is 750 kW.Then,considering the local climate characteristics and the characteristics of energy resource endowment,the solar and water source heat pump composite heating system was constructed,the composition form,operation mode and control strategy of the system were introduced,and the main equipment of the system was selected and calculated.Secondly,relying on the TRNSYS software platform,a model of the composite heating system was built to verify the reliability of the model,and the simulation analysis of the continuous operation of the heating period was carried out using the built model of the composite heating system to derive the system energy consumption and system performance of the composite heating system in continuous operation during the heating season.The solar and water source heat pump composite heating system applied in alpine regions such as Shigatse,Tibet,operates well.The water supply temperature of the composite heating system is concentrated in the range of 45～54℃,and the maximum supply and return water temperature difference is about 10℃,and the average performance coefficient of the system is 4.43.Again,the capacity optimization design of the key parameters of the composite heating system was carried out,and the optimal inclination angle of the collector of the composite heating system was determined to be 50.6°,the optimal azimuth angle was 2.6°,the collector area was 2636 m~2,and the volume of the heat storage tank was 268m~3.the energy consumption of the system was reduced after optimization,and the performance coefficient of the system was increased to 5.14,compared with that before optimization,the performance coefficient of the system was improved by 13.3%compared with before optimization.Finally,the overall benefits of the composite heating system were evaluated,and the composite heating system had the highest overall benefits compared to the other two conventional heating systems.