Research Of Ground-source System Of Sensible Treatment Source-side In Hot Summer And Cold Winter Area

In recent years, the design concept of temperature and humidity individually controlled air conditioning developed gradually at home and abroad. Not only the temperature and humidity independent control air conditioning system can provide a more comfortable living environment for people,but also can save electric energy, and even low-grade heat can be used to be power so as to reducing system power consumption. As an important part of the temperature and humidity independent control system, the sensible heat treatment system only bear the indoor sensible heat load, so the chilled water temperature can be increased to above 18℃, so a lot of natural cold source can be used. Soil source heat pump gains more and more attention because of its energy saving features, and its research, optimization in the design and operation and so on are also constantly evolving. It is the combination of two kinds of new energy saving technologies and new ideas that using the soil source heat pump to treat the sensible heat load of the building, not only meeting the people on environmental quality requirements,but also achieving energy saving system. This paper analyzed the source-side of soil source sensible heat treatment from the theoretical analysis, simulation, the application of system and so on.Firstly, soil source sensible heat treatment system theory and design method are introduced and analysized, then established pipe quasi-three-dimensional heat transfer model according to the principle of energy balance, the heat transfer performance and changes in soil temperature field of underground pipe are simulated by means of ANSYS software, and made a comparison between the thermal test results and simulation results. It shows that the average relative error of per meter borehole heat exchange amount and drilling depth respectively is about 5.3% and 1.3%,which verifies that the heat transfer model is accurate and reliable. Then for different water temperature, pipe spacing, load characteristics, different running plan in the soil source sensible heat treatment, the simulation analysis was carried out. The results show that the higher average water temperature of buried pipe can improve the capacity of heat transfer of buried pipe; the larger pipe spacing can reduce the influence of the thermal interference between the pipe group; the intermittenting operation of buried pipe is more suitable ground source heat pump system; when soil source directly supply high temperature cold water, due to the average temperature is low, cooling capacity is limited, it should be used when the sensible heat load is smaller, and the recovery capability of soil temperature field enhanced because of increasing operation of soil direct cooling mode, so it good for keeping long-term running efficiently of the soil source sensible heat treatment system. For the operation control of source-side of soil source sensible heat treatment system, raising a buried pipe arrangement and operation optimization strategy in accordance with the district and load characteristics. The simulation results show that this method can effectively reduce soil temperature rise, to maintain efficient operation of soil source sensible heat treatment system.Finally, the research results were used in an office building in Hefei, design results show that the number of drilling in soil source sensible heat treatment system reduced about 50% comparing with conventional ground source heat pump systems, we can choose a larger tube spacing in a limited area of the buried pipe, so as to reducing the thermal interference between pipes. Then annual energy consumption and carbon emissions of the temperature and humidity independent control system based on soil source sensible heat treatment, conventional ground-source heat pump system and conventional air conditioning system with chiller plus gas boiler were analyzed and calculated, the comparison among the three calculation results show that the soil source sensible heat treatment system has significantly better energy and environmental benefits.