Simulation And Evaluationg On Solar Ground Coupled Heat Pump Heating System

In recent years, the geographical scope affected by smog in China is increasingly wider than before. Especially the northern cold areas, in heating season, the air polluting will get much more serious. Smog has become a hot topic in the daily life of residents. Government attaches great importance to the issue of air pollution and introduced more stringent environmental policies and regulations. Solar energy and geothermal energy are the most widely used new energy sources in the construction field, but the application of solar energy and soil source heat pump in the construction of heating has some problems. Under this background, this context put forward a solar-ground coupled heat pump with seasonal storage heating system considering the advantages and disadvantages of the ground source heat pump and solar energy utilization in practical operation. Seasonal thermal storage refers to using the solar energy to compensate heat of soil in non-heating season. This system will provide a solution to the problem of ground source heat pump’s imbalance of soil temperature in a long running time and utilize solar energy as a heat source in winter to promote heat pump’s heating efficiency.In this paper, a residential building in Beijing city is used as the research object; solar collectors are connected in series with ground heat exchangers. With the data of the hourly load of building getting from the De ST analyzing software, carry out specific system design. The application components and mathematical model of TRNSYS dynamic simulation software are introduced in this paper and using TRNSYS simulation software as a platform to verify the feasibility of the system. The daily and monthly heat storage of soil during the non-heating season、heat supply and COP of the heat pump unit、soil temperature change in a year are analyzed to study the operation characteristics of system in a year of simulation time. Analyzing the temperature and heat storage and discharge capacity in ten years of simulation time to confirm that thermal unbalance rate of soil in ten years which illustrates the system runs stably in the simulation time of ten years. On the basis of the simulation model, different length of ground heat exchangers is analyzed to see its impact on system’s operation characteristics. It turns out different best choices considering the stability of the COP value of the heat pump unit and heat storage capacity of soil and heat supply of heat pump unit.In the end, this paper the seasonal storage of solar ground source heat pump heating system and traditional coal-fired boiler were analyzed in benefit, including economic efficiency, energy efficiency and environmental benefits. Although the system of static investment payback period is a pretty long time, but from the point of view of environmental protection and sustainable development, the system is very potential, and is suitable for promotion in the region.