地源热泵冬季工况土壤温度变化特性研究-供热、供燃气、通风及空调工程专业论文.docxVIP

华 华 中 科 技 大 学 硕 士 学 位 论 文 II II Abstract The GSHP (Ground Source Heat Pump system) is a new heat pump technology which grows up with the advent of the global environmental problems and energy crisis. The GSHP uses the energy which stored in the soil within 200m underground to serve for heating and air conditioning in buildings. It has good energy saving and environmental benefits, and gets increasingly wide attention and application in china recently. This paper focus on the GSHP system in a 3-level office building in wuhan, the purpose of which is to study the soil temperature field changes under dynamic load. First by using the building energy consumption analysis software EnergyPlus to get the building’s max heating and cooling load. And then simulate the whole GSHP system according to the actual situation to get the hourly water temperature that enters the U-tube. In order to provide advice and reference for the GSHP design and construction, this paper use Fluent to simulate the radius of 2.5m area to get the soil temperature field changes under two different boundary conditions during the heating period and the outage. The results show that, during the winter condition, the outlet water temperature and the soil temperature changes are contrary to the heating load changes during the heating session, and the soil temperature decrease gradually from the center to distal. The soil temperature recovers fast under the constant wall temperature boundary condition, while keeps falling down under the adiabatic boundary condition as the ground heat exchanger absorbs heat from the soil continually. The soil temperature recovers much faster in the first five days after the units shut down, and then gradually slow later on. The distal soil temperature changes small under the constant wall temperature boundary condition, and the whole area temperature will rise to the wall temperature in a long term recovering. While the distal soil temperature keeps falling under the a