Analysis of the Thermal Characteristics of Surrounding Rock in Deep Underground Space

Liu Chen,Bo Zhang,Fei Han,Jiangbo Li,Lang Liu,Yu Zhang

doi:10.1155/2019/2130943

Abstract

With the development of society, the economy, and national security, the exploitation of deep underground space has become an inevitable trend in human society. However, high-temperature-related problems occur in deep underground spaces. The high temperature of deep underground space is essentially influenced by the thermal characteristics of the surrounding rock. According to the mathematical model of heat transfer of the surrounding rock in deep underground space, similar criteria numbers are established. Experiments were carried out to investigate the thermal characteristics of the surrounding rock. The distribution characteristics of temperature were determined by the Fourier number (Fo) and Biot number (Bi), and the effects of heat transfer time, airflow velocities, and air temperature and radial displacement on the distribution characteristics of temperature were studied. The results indicate that the surrounding rock temperature decreases with long heat transfer times, high airflow velocities, and low air temperatures.

Highlights

As an important part of urban space resources, underground space is an important way to promote urban sustainable development ability [1, 2]. ese uses of underground space include the installation of transportation infrastructure, public utilities, disposal of waste, energy utilization facility, storage of substances, and exploitation of minerals [3,4,5,6,7,8,9]
E challenges associated with deep underground spaces include high temperatures, which are harmful to human health, and decreased production efficiency [11, 12]
Numerical simulation was utilized to study the effect of heat generated after burying radioactive waste on the stability of underground space and the surrounding rock strata for 16 years at a constant heat flux [14]. e random temperature fields of a tunnel in a cold region were obtained by numerical simulation and analysed with stochastic boundary conditions and random rock properties [15]. e steady heat transfer of surrounding rocks in roadway ventilation was numerically analysed. e heat flux was approximately uniformly distributed in a ring shape

Summary

Introduction

As an important part of urban space resources, underground space is an important way to promote urban sustainable development ability [1, 2]. ese uses of underground space include the installation of transportation infrastructure, public utilities, disposal of waste, energy utilization facility, storage of substances, and exploitation of minerals [3,4,5,6,7,8,9]. Extensive research on the heat characteristics of surrounding rock in deep underground spaces has been conducted using theoretical, numerical, and field test methods, there are only a few experimental studies, most of which are focused on steady heat transfer rather than unsteady heat transfer. Is study aims at experimentally investigating the unsteady thermal characteristics of surrounding rock in deep underground space. To model the heat transfer of surrounding rock in deep underground space, the following simplified assumptions are made:. E mathematical equations governing the heat transfer of surrounding rock in deep underground space are shown as follows: zT z2T 1 zT zτ a􏼠 zr. E dimensionless equations governing the heat transfer of surrounding rock in deep underground space are shown as follows: zΘ 1 zΘ z2Θ. Erefore, the conclusion is obtained as follows: the Fourier number Fo and Biot number Bi are the similar criteria numbers of surrounding rock in deep underground space

Experimental Method

Results and Discussion

Conclusions