Simulation Study On Solar Energy-Ground Source Heat Pump Composite System Of Grain Warehouse

Solar energy and shallow geothermal energy are green and renewable energy sources.In order to respond to the call of the national "double carbon" policy and solve the problems of high energy consumption and high cost of grain storage in grain warehouse,this paper puts forward the combination of solar energy and shallow geothermal energy for grain storage to achieve the goal of "zero energy consumption" and "zero emission".In recent years,photovoltaic power generation and shallow geothermal energy comprehensive utilization technology have been widely used in civil buildings,but there are few applications in grain and oil storage buildings,and there is a lack of targeted research and analysis.Therefore,this paper constructs a simulation model of solar energy-ground source heat pump composite system,and studies the feasibility of the application of the system in the reservoir area from the aspects of operational performance,photoelectric adaptability,economy,energy saving and environmental protection effect.In this paper,the grain warehouse directly under Ganzhou Grain Storage Company is taken as the research object.Based on Sketch Up software and transient simulation software TRNSYS,the building model of the grain warehouse is established,and its operation performance is dynamically simulated under high temperature in summer.By comparing with the test data of the real warehouse,the accuracy of the model is verified.According to the maximum instantaneous cooling load of grain storage area,the solar energy-ground source heat pump composite system is designed and selected.By comparing the test data of Ganzhou warehouse with the simulation results,the maximum relative errors of ambient air temperature and air insulation layer temperature are14.7% and 9.1% respectively,which verifies the accuracy of granary building model and the setting of granary environmental response mechanism.On this basis,the air insulation layer temperature,total energy consumption and operating performance coefficient of the air source heat pump system currently used in grain warehouse are simulated and analyzed.The simulation results show that the air source heat pump system will have the problems of low refrigeration efficiency and high energy consumption when refrigerating the granary.In order to improve the shortcomings of the existing air source heat pump system,this paper optimizes the refrigeration system of grain warehouse and constructs the simulation model of solar energy-ground source heat pump composite system.In order to explore the feasibility of realizing "zero energy consumption" low-temperature grain storage with solar energy-ground source heat pump composite system,the operating performance of the system was analyzed.The main contents include the temperature and humidity in the granary under the cooling condition in summer,the performance of the underground pipe system and photovoltaic system,and the feasibility of the operation strategy of the solar-ground source heat pump composite system is verified by the soil heat balance and the system energy efficiency ratio during the long-term operation of the system.By comparing the total energy consumption of the system with the photovoltaic power generation,the photoelectric adaptability and residual electricity utilization of the composite system are studied.Based on the above research,this paper analyzes the economic and energy-saving effects of solar-ground source heat pump composite system from the aspects of static investment payback period,emission reduction of harmful substances,cost saving of harmful substances treatment and evaluation of carbon neutrality.The results show that the payback period of single warehouse investment is 7.8 years;Compared with the air source heat pump system,the ground source heat pump system can save energy by 59%,reduce the emission of harmful substances by 38.41 t/a,and save the treatment cost of harmful substances by 4432 yuan /a.Solar energy-ground source heat pump composite system can control the emission of greenhouse gases from the source and realize "zero emission" low-temperature grain storage.