In order to search the effect of soil freezing on heat exchange characteristics of ground heat exchangers in cold zone,develops a heat transfer model of soil around ground heat exchangers taking soil freezing into consideration,and solves the freezing phase change problem by apparent heat capacity method.

Based on the numerical calculus of soil freezing and the apparent heat capacity method, completely and partly implicit difference schemes of the heat transfer equation were deduced by the finite difference method with variable space step.

Based on the basic equations of simultaneous soil water and heat transfer during soil freezing, the coupled equation of moisture and heat is deduced.

Review of the study on land surface process in soil freezing and thawing;

Coupled model of moisture and heat reaction during soil freezing and thawing under environmental climate condition

Using the model of simultaneo us moisture and heat transfer during soil freezing and thawing, a numerical sumulation is carried out to the whole course of freezing and thawing in Hetao irrigation areas in Inner Mongolia Autonomous Region.

The difficulties in the establishment and solution for mathematical model of frost heaving of soil are introduced.

BP network model research on water and salt transfer forecast in seasonal freezing and thawing soils;