Investigating nonlinear flow and heat transfer in rough fractured rock by considering fluid phase transition
Research on seepage and the law of heat transfer in three-dimensional(3D)rough fractures is important to improve the rate of heat extraction from underground thermal reservoirs.Although substantial progress has been made in addressing the multi-field problem of coupling encountered in the current process of thermal recovery,the effect of the phase transition on seepage and heat transfer through fractures has rarely been investigated.This study uses Fluent software to establish single-phase and multi-phase models of coupling of heat flow to analyze the nonlinear flow and mechanism of heat transfer in 3D rough fractures under the influence of the phase transition of the fluid.The numerical results showed that the local roughness of the rough fracture surface controlled the distribution of the coefficient of local heat transfer when the phase transition of the fluid was not considered.Moreover,the results of the Forchheimer formula showed that the heat transfer of the fluid significantly influenced nonlinear seepage through the fractures.When its phase transition was considered,the fluid exhibited characteristics similar to that of a shear diluted fluid,and the volume percentage of gas played a dominant role in heat transfer.This shows that considering the phase transition of the fluid can reveal the accurate characteristics of seepage and the law of evolution of the efficiency of heat extraction during thermal recovery.
万方数据
维普
