Heat Transfer And Economic Analysis Of Ground Source Heat Pump System Under Contract Energy Performance Mode

As one of the important technologies in the field of building energy conservation,ground source heat pump technology has been widely used in various countries all over the world.However,in the process of using ground source heat pump technology,there are some problems such as unreasonable design,irregular construction,improper operation and maintenance.In some projects,capital and technical level constraints also restrict the use of ground source heat pump technology.The application of energy performance contracting mode can provide financial and technical support for ground source heat pump project.Therefore,it is very necessary to study the application of energy performance contracting in ground source heat pump project.In order to study how to apply contract energy management to ground source heat pump projects,this paper first analyzes the operation mode of contract energy management and the operation process applied to ground source heat pump projects.Secondly,taking a university library project in Shijiazhuang as an example,the applicability of the ground source heat pump system in this project is analyzed,and the building energy consumption is simulated and analyzed by using De ST software.At the same time,in order to ensure the operation efficiency of the system,the energy saving service company uses Fluent software to analyze the heat transfer of the underground buried pipe of the ground source heat pump system,and analyzes the best design scheme by changing the drilling spacing,drilling depth and inlet velocity.Finally,the benefits of all parties in the ground source heat pump project under the contract energy management mode are analyzed by using the method of engineering economics.The results show that in this project,it is feasible to apply the contract energy performance to the ground source heat pump system.According to the heat transfer analysis of buried pipes,it is found that the increase of drilling spacing significantly reduces the cold accumulation phenomenon between buried pipes.When the drilling spacing is 5 meters,the outlet temperature of buried pipes tends to be stable,and when the spacing exceeds 6 meters,the outlet temperature changes little.The increase of drilling depth leads to the improvement of heat transfer performance of buried pipe.When the drilling depth exceeds 110 meters,the change trend of soil temperature tends to be consistent.The heat transfer efficiency of buried pipe increases gradually with the increase of inlet flow rate,but when the inlet flow rate is greater than 0.8 m/s,the temperature difference between the inlet and outlet of buried pipe is too small and the heat transfer does not change much.The energy service company can ensure the efficiency of the system and reduce the investment cost of the project through numerical analysis.At the same time,the economic analysis of ground source heat pump system found that compared with the traditional air conditioning system,it can save energy costs 1.617 million yuan per year;incremental investment can be fully recovered within7.23 years;the annual CO₂ emission can be reduced by 797.41 t,SO₂ emission by 6.46 t,and dust emission by 3.23 t.Within the years of signing the contract,the energy service company received CNY 1.4553 million per year,and the energy consumption unit received CNY 0.1617 million.After the contract period,the energy service company received CNY11.6424 million in total.Based on the above analysis,it is found that the energy performance contracting is applied to the ground source heat pump project.From the economic,environmental benefits,energy service company and energy consumption units,not only energy service company and energy consumption units get economic benefits,but also play a role in energy conservation and emission reduction.