Research On Prevent Freezing Expansion System Of Retaining Wall In Seasonal Frozen Based On Ground Source Heat Pump

Under the action of freeze-thaw cycle, it is easy to produce foundation frozen to pull out, wall crack, or even fall in the retaining wall which have been built. This kind of problems can influents its durability and reduce its service life seriously. On the other hand, simple maintenance can’t resolve the problems ultimately. So, the retaining wall which have been built always in the " sick running "state. Therefore, it is important to research the prevent freezing expansion system of retaining wall in seasonal frozen.Based on comprehensive consideration of our country’s energy, economy, environment and technology, a new type of system which is used to prevent freezing expansion is presented, this system based on ground source heat pumps, by which ground heat is prompted by heat pump, and is supplied to the filled soil for retaining wall-heating. This new type of system not only solves the problems of the retaining wall’s which caused by the low temperature, but also makes good use of renewable ground heat and achieves the purpose of saving energy.Through theoretical analysis and numerical method, the distribution of temperature field in the filled soiled is analyzed in this paper, in addition, the design and construction of ground source heat pump is introduced too. Main contents are as follows:(1) After comprehensive considerates all kinds of boundary conditions, such as heat conduction, heat convection, temperature and so on. This paper simulates the transient temperature field of seasonal frozen retaining wall, and gets the distribution of temperature field, at the same time, the author analyzes the change-law of the filled soil’s temperature, and gets the biggest frozen deep of filled soil. This achievement not only provides theory basis for the design of the ground source heat pump, but also lays a foundation for the future study.(2) Take the temperature of filled soil as the control condition, this paper simulates the temperature field under different working conditions respectively, and gets the distribution of temperature field. In addition, based on comprehensive consideration of the service life of heating tube, energy consumption and the action of extreme climate, this paper determines the arrangement of the heating tube and the temperature of heating fluid.(3) According to the maximum thermal load value of retaining wall, the author analyzes the depth, the spacing and the number of the buried tube quantitatively, and then choose the equipment which is used in the unit. At last, the author introduces the construction of some key parts detailedly, such as backfilling, hot melt, and so on.In a word, the retaining wall-heating based on the ground heat pump system was fundamentally studied and its feasibility was validated in this paper, which lays the foundation for the further study of this system and extents the application field of ground source heat pump from HVAC areas to other areas.