Study On Optimum Design Of Solar-Soil Source Heat Pump System In Qingdao

Solar and geothermal heat pump heating systems are now widely used in many areas.Compared with the air heat pump unit,the heating performance of the heat pump unit is more stabilized,and the running cost is relatively low,but the temperature of the deep soil is much lower due to the heat from the soil.Solar heating is the most clean way of heating,but it's a great impacted by the outdoor weather conditions,and low flow density,easy to use limited.Therefore,the use of both the advantages and disadvantages of the establishment of solar and ground source heat pump coupled heating system,and a reasonable allocation of the two running time,help to reduce the use of soil source heat pump thermal imbalance caused by enhanced heat stability,while Help to ease the pollution caused by heating and reduce operating costs.This paper focuses on the Qingdao area as an example,for a rural independent residential use of solar-ground source heat pump system to optimize the design and analysis.The user's original heating method for the gas boiler,is now changed to solar-ground source heat pump system.Through the theoretical analysis of the optimal running time ratio of the alternate operation mode,the optimum area of the collector is determined by the solar guarantee rate after determining the working time ratio of the solar energy and ground source heat pump.The system can minimize the running time of the ground source heat pump when the sun is sufficient,which can not only reduce the running cost but also the recovery of the soil temperature and reduce the heat of the soil.Due to the high initial investment of the solar collector system,the results of this paper are of guiding significance for setting the appropriate collector area and reducing the system cost.In this paper,the characteristics of solar heat source and soil heat source are analyzed,and the heat transfer process of solar collectors and the heat transfer mechanism of buried heat exchangers in soil are analyzed correctly and the alternation of solar-ground source heat pump system The model of the model has been modeled and simulated.Based on the soil temperature calculation model,the distribution characteristics of the original temperature of the soil during the heating season in Qingdao were analyzed.The distribution law of the soil temperature field around the buried heat source was studied.The soil temperature recovery model was established,Dimensional non-steady-state axisymmetric cylindrical equations are discretized.The results of the study determine the optimal state of the soil temperature recovery rate near the coil when the system is running alternately,and calculate that the time of the solar heat pump system should be controlled at 45.8%,thus determining the size of the collector area,And the use of energy balance method to introduce the solar load rate and the collector area into a linear relationship.Due to the limitation of the conditions,this paper only simulates the heating operation and equipment selection of the solar-ground source heat pump system in Qingdao.The results of the simulation are still to be verified by experiments.The purpose of this paper is to provide a reference for the practical design,operation and management of solar-ground source heat pump system.