地热储层单裂隙岩体渗流传热数值模拟研究

研究地热储层裂隙岩体中的渗流传热过程对干热岩地热资源的开采具有重要的意义。本文以干热岩地热工程为背景,采用COMSOL Multiphysics数值模拟软件对地热储层单裂隙岩体中渗流传热机理进行了研究,并分析了流体注入速度和温度对岩体温度场的影响及其对干热岩地热工程的影响。研究发现流体参数对岩体温度场的影响主要体现在两个方面：一方面是对岩体温度场受扰动区域以及幅度的影响,另一方面是对岩体温度场达到稳态所需要时间的影响。流体注入速度的提升会降低系统的寿命和寿命期的出口法向总热量值,当考虑出口法向总热通量时,存在最佳流体注入速度,本研究中最佳流体注入速度为0.011m/s。流体注入温度的提升会增加系统的寿命和系统的出口法向总热通量和总热量。研究为干热岩自热资源的开发与利用提供了理论依据,为工程运行参数的设计提供了参考依据。

Numerical simulation of seepage and heat transfer in single fractured rock mass of geothermal reservoirs

It is of great significance to study the percolation and heat transfer in fractured rock mass of geothermal reservoir for the exploitation of geothermal resources in dry hot rocks. In this paper, based on the geothermal engineering of hot dry rocks, the numerical simulation software of COMSOL Multiphysics was used to study the mechanism of seepage and heat transfer in single fractured rock mass of geothermal reservoirs, and the influence of fluid injection velocity and temperature on the temperature field of rock mass and on the geothermal engineering of hot dry rocks was analyzed. It is found that the influence of fluid parameters on the rock mass temperature field is mainly reflected in two aspects: on the one hand, the influence of the disturbed region and amplitude of the rock mass temperature field; on the other hand, the influence of the time needed for the rock mass temperature field to reach steady state. The improvement of fluid injection rate will reduce the system life and the total outlet normal heat value during the life period. When considering the total outlet normal heat flux, there exists an optimal fluid injection rate, which is 0.011m/s in this study. The increase of fluid injection temperature will increase the life of the system and the total normal heat flux and total heat at the system outlet. This study provides a theoretical basis for the development and utilization of dry hot rock self-heating resources and a reference basis for the design of engineering operation parameters.