Ground Source Heat Pump Based On TRNSYS In A Building In Beijing Study On System Operation Optimization

With the continuous development of the construction industry,building energy consumption is increasing rapidly.Energy conservation is of great importance to our society.Therefore,it is necessary to study alternative energy sources and improve the equipment and methods to ensure the microclimate,heat and cold supply of buildings.Ground source heat pump system is a widely used and effective energy saving equipment,which can provide heat and cold source for buildings.It is a renewable energy application technology by extracting heat from soil.In this thesis a building in Beijing is taken as the research object,and mathematical relations are respectively established for the ground source side,unit side and terminal load side of the ground source heat pump system,laying a theoretical foundation for the establishment of the simulation system model.Then,the operation data of two months in winter are tested and sorted out through the energy intelligent management platform.Analysis of running data,it is found that the COP performance coefficient is low and the system needs to be optimized.The operating parameters that affect COP are found out.Correlation of effect element was analyzed using the Spearman method,and the influencing factors with the maximum correlation with COP are obtained.Spearman method was used to analyze the correlation of influencing factors,and the influencing factors with the greatest correlation with COP were obtained.The TRNSYS simulation model was established by using TRNSYS to simulate the long-term running state and obtain the running results.The TRNSYS simulation model was verified by the measured data.The variation trend of the model simulation results was consistent with the tested results,and in the theoretical error area,the simulation operation was considered to be consistent with the actual operation.Finally,through the simulation analysis of the whole year normal load of the system,it can be concluded that the COP in winter is gradually increasing,and the COP in summer is gradually decreasing,but the average COP is decreasing year by year.According to the results of correlation analysis,the most influential factors of COP were selected to optimize the control.Indoor load changes largely affected by the outdoor temperature,and the daily outdoor temperature change is very big,the cold and hot water supply is bound to be a constant temperature losses,in order to reduce the loss of ground source heat pump system with variable water temperature control of the load side,it is concluded that the optimized system running as a result,through the analysis of the results of a typical day,After optimization,the temperature difference on the ground source side increased by 1.06℃,the temperature difference on the load side increased by 0.97℃,and the COP increased by 0.25,or 6.11%.System energy consumption decreased by 13.74 k Wh,7.55%;Furthermore,the overall energy saving rate of unit energy consumption reaches 10.54%,water pump energy consumption reaches18.95%,and system energy consumption reaches 14.30%.COP increased by 0.44,or15.33%;The absorption and release ratio of buried soil decreased from 1.63 to 1.51,decreasing by 7.36%.The soil temperature decreased by 1.56℃(7.26%)in 10 years before and after optimization,which was beneficial to soil cold and heat balance and long-term operation of the system.