The Simulation Study Of Solar-soil Source Heat Pump Hot Water System Based On TRNSYS Software

With the rapid development of society and the continuous improvement of living standard, providing hot water for students has become a essential living facility in current university student apartment, but it also causes the growth of building energy consumption. So, putting forward a hot water supply way which is energy saving, economic and environmental protection for the university student apartment has become extremely urgent, which meet the requirements of the national energy conservation and emissions reduction and also is a reflection of the people-oriented concept of the school.As everyone knows, soil source heat pump provides heating and cooling for building by absorbing or releasing heat from the earth, which consumes the secondary energy (electricity). But the initial investment of the soil source heat pump is largely, at the same time long running of the system can cause soil temperature continues to decline or increase which cause the decrease of the performance coefficient of the heat pump. Solar energy is a kind of never dried up,clean and renewable energy, but it is intermittent and unstable. Combining the two kinds of renewable energy to provide living hot water can maximize the utilization of renewable energy.Basing on a solar-soil source heat pump hot water system of student apartment in Hunan, this article takes TRNSYS software as a platform for the complex hot water system simulation. The simulation mainly include the heat transfer of every heat source, solar assurance, solar thermal efficiency, heat transfer of soil, heat imbalance rate, power consumption and economical efficiency of the system, the simulation results show that the method of using solar energy to adding heat for buried tube heat exchange system in winter and summer vacation is feasible, which can keep the soil heat imbalance rate nearly below20%, the COP of the ground source heat pump system can reach more than4.0within20years. With the increase of system’s running time, the imbalance rate gradually decreases as so as temperature drop rate. Relative to the conventional energy hot water system, the composite hot water system can save operating cost250700yuan a year,electricity consumption386900kW-h and reduce carbon dioxide emissions by385.73t,economical and environmental benefits are considerable.