Research On Transformation Of Heating And Cooling System Of Old Office Building In Cold Region

Green building is the building to realize the rational and effective utilization of resources and environment-friendly utilization.Among the energy consumption of buildings,public buildings account for the largest share,and office buildings account for the largest number,accordingly,it is necessary to find ways to cut down the energy consumption of office architecture,especially the development of energy-saving and consumption reducing technologies for old office architecture.Harbin is located in the cold region of China with high heating/cooling energy consumption.One of the significant energy-saving means in green buildings is GSHP technology,which can efficaciously shorten the energy consumption of architectures.Accordingly,aiming at the problem of large heating and cooling energy consumption of old office buildings in cold regions,this paper carries out energy-saving transformation and research combined with GSHP technology and other green building energy-saving means.Based on the Harbin district heating demonstration project,this paper summarizes the relevant data of heating period for three years.The consequences reveal that the inlet and outlet temperatures of ground source heat pump first decrease and then slowly increase.Moreover,the temperature difference between the inlet water and outlet water in three years is approximately 4℃;the heating COP in three years is above 3.15;the decline rate of soil temperature first increases and then decreases with the change of outdoor temperature;the electricity cost per unit area of ground source heat pump in three years is 33.50%、31.90%and 30.28%lower than that of traditional central heating.The experimental consequences reveal that the ground source heat pump is feasible in building heating in cold regions.Based on the experimental results,the model of building load and ground source heat pump system is built by using the numerical analysis software(TRNSYS)to simulate the relevant parameters of heating in three years.The simulation consequences are compared with the experimental data,and the error is less than 5%of the allowable error limit.For an old office building in Harbin,the ground source heat pump operation mode is adopted,under the condition of providing heat energy in winter,adding summer refrigeration technology under the condition of winter heating can effectively improve the operation efficiency and comfort of office buildings.The numerical results show that COP in heating season and cooling season is about 3.26 and 4.25,and the soil temperature decreases by 2.59%after one year of heating and cooling.In this paper,the ground source heat pump system is designed to increase refrigeration in summer,effectively reduce energy consumption,in line with the requirements of green building energy saving.In order to better improve the recovery of soil temperature,solar energy heat supplement measures were added,and the changes of relevant parameters with buried depth of 100m and 350m were simulated respectively,and compared with the single ground source heat pump to find the optimal scheme.It is found that when the depth is 350m,the COP of the cooling season and the heating season fluctuate at about 4.26 and 3.27,which are both higher than that of the single GSHP system.The soil temperature drop rate decreased by 0.41%and 1.35%respectively,which proved the feasibility of the solar GSHP system.GSHP and its coupling system are compared with the conventional heating and cooling mode in terms of energy saving,environmental protection and economy,and the corresponding evaluation is carried out combined with the green building standard.It is found that the energy-saving efficiency of the solar coupled geothermal pump system with a depth of 350 meters is the maximum and the effect of reducing emissions is the best,with the initial capitalization of 1.18 million yuan as the lowest value,the annual operating cost of 105000 yuan,the shortest payback period,the lowest annual cost and the most economic.The highest score of green building is 82.Comprehensive analysis of 350m deep buried solar ground source heat pump system is the greatest heating and cooling transformation scheme for old office buildings in cold regions.