| This paper based on the background of the studies for the deep geological disposal of high level radioactive waste, researched the characteristics of regular fractured granite rocks under heathing、water flow and pressure coupling conditions and the theory of convective heat transfer in fracture. The main contents and results of this thesis as follows:(1)The experiment model was made up with thirty-two blocks of granite of Bcishan region, involved three pairs of relatively fractures which filled with standard sand distributed along the horizontal and vertical line uniformly. The model is under the condition of vertical water flow、heating on the right side and pressed on the left side to simulate the thermo-hydro-mechanical Coupling processes. The experiment results revealed:the filled saturated fractures controlled the temperature distribution in the model, and the fracture adjacent to the heat is the main factor.(2)The pressure made the fracture aperture and the porosity of standard sand getting smaller, which made the infiltration rate of water getting slow, lengthened residence time of water in the fracture, and increase the convective heat transfer. Meanwhile, because of the change of fracture aperture and the porosity of standard sand, the retardation of fracture to the heat transfer was reduced obviously. More the retardation of fracture reduced, the more heat conduction in vertical direction became strong.(3) The research surface heat transfer coefficient in saturated rock fracture is in beginning stage, this paper contrasted the applicable scope and basic characteristics of different experimental correlations formula, and analyzed the suitability at rock fracture of them. Analyzed the flow condition and solving method in single saturated fracture according heat transfer theory. And calculation theory analysis of the surface heat transfer coefficient for a single saturated fractured pipe are given. |
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