Analysis On Tempeture Field And Humidity Field Of Uuderground Heat Exchanger In Winter

(?)und source heat pump system has great advantage in energy saving, scholars from domestic and foreign countries have made many studies in heat transfer conditions between underground u-tube heat exchanger of ground source heat pump and soil, these studies are mainly based on thermal conductivity theory of heat transfer between underground u-tube heat exchanger and soil, but the studies based on the heat and moisture coupled theory of heat transfer between underground u-tube heat exchanger and soil are little. This paper make a study on temperature and moisture fields with time under the coupled heat and moisture conditions in winter, and analyze influence factors of soil temperature and moisture field of underground heat exchanger in winter.Firstly, one-dimensional heat and moisture transfer equation of u-tube heat changer was established, this equation was discretized by the finite difference method and was programmed with VB, then the program calculate the temperature and humidity field values of equation iteratively and finally calculate the soil temperature and humidity field values in different time and spacing in winter.Secondly, according to soil temperature and humidity field distribution of single underground u-tube heat exchanger under the coupled heat and moisture conditions, the effects of moisture value on soil temperature field was analyzed; change of soil temperature and moisture fields with different distance was analyzed when distancec is changged.Thirdly,simulation error is analyzed according to temperature field data of ground source heat pump laborary comparised with VB programme results.