Research On Greenhouse Heating System Of Solar Energy Coupled Ground Source Heat Pump Based On TRNSYS

In recent years,the work of replacing coal-fired heating with clean energy has been vigorously promoted,in which the solar energy,geothermal energy and other clean energy for heating in northern China has good economic and environmental benefits.However,the experiment time span of solar energy coupled ground source heat pump system used in greenhouse heating in cold area was long,and the basic design principles of the soil thermal imbalance problem in ground source heat pump was lack.In this paper,the simulation model of solar energy coupled ground source heat pump greenhouse heating system was constructed.The operating characteristics of the coupled heating system were studied.The design principles of matching collector area for coupled heating system and operation mode of solar heat pump were proposed,which were applied to agricultural greenhouses.Firstly,the TRNSYS simulation model of the solar energy coupled ground source heat pump heating system for greenhouse heating was constructed.The error between the simulated results and the experimental value was within ±2.5%,and the maximum difference between the obtained average soil temperature and the measured value was not more than 0.09℃,which verified the simulation model.Then,based on the simulation model,the influences of components,parameters and control strategies on the coupled heating system were studied,and the operating conditions of the system under long-term operation conditions were predicted and analyzed.The results show that the system was affected by the solar collectors obviously.And the system has the best control strategy.With the long-term heating,the soil temperature of the coupled heating system can keep the ground temperature above 14.68℃,and the COP of the system is 18.8% higher than the ground source heat pump heating system.Finally,a solar energy coupled ground source heat pump system for engineering agricultural greenhouse heating was designed and the simulation model was constructed.And a matching principle for the collector area of the system was carried out.The operation mode of the system was compared and the economy was evaluated.The results show that compared with the old system,the energy consumption of the coupled heating system with the operation mode of solar heat pump for agricultural greenhouse heating was reduced by 2.6%,COP was increased by 0.14,and the annual cost was reduced by 27.5% compared with the electric heating system.The economic and environmental benefits were remarkable.This research can provide technical reference and theoretical support for clean heating in the agricultural sector in northern my country.