Influence and sensitivity analysis of thermal parameters on temperature field distribution of active thermal insulated roadway in high temperature mine

Weijing Yao,Qinyong Ma,Happiness Lyimo,Jianyong Pang

doi:10.1007/s40789-020-00343-y

Abstract

To study active heat insulation roadway in high temperature mines, the typical high temperature roadway of − 965 m in Zhujidong Coal Mine of Anhui, China, is selected as prototype. The ANSYS numerical simulation method is used for sensitivity analysis of heat insulation layer with different thermal conductivity and thickness, as well as surrounding rock with different thermal conductivity and temperature on a heat-adjusting zone radius, surrounding rock temperature field and wall temperature. The results show that the heat-adjusting zone radius will entirely be in the right power index relationship to the ventilation time. Decrease in thermal conductivity and increase in thickness of insulation layer can effectively reduce the disturbance of airflow on the surrounding rock temperature, hence, beneficial for decreasing wall temperature. This favourable trend significantly decreases with ventilation time, increase in thermal conductivity and temperature of surrounding rock, heat-adjusting zone radius, surrounding rock temperature field, and wall temperature. Sensitivity analysis shows that the thermal physical properties of surrounding rock determine the temperature distribution of the roadway, hence, temperature of surrounding rock is considered as the most sensitive factor of all influencing factors. For the spray layer, thermal conductivity is more sensitive, compared to thickness. It is concluded that increase in the spray layer thickness is not as beneficial as using low thermal conductivity insulation material. Therefore, roadway preferential consideration should be given to the rocks with low temperature and thermal conductivity. The application of the insulation layer has positive significance for the thermal environment control in mine roadway, however, increase in the layer thickness without restriction has a limited effect on the thermal insulation.

Highlights

Deep mining of underground engineering is normalised and the thermal environment of mine, caused by high ground temperature, restricts further excavation (Yi et al 2019; Xie et al 2012)
The ANSYS numerical simulation method is used for sensitivity analysis of heat insulation layer with different thermal conductivity and thickness, as well as surrounding rock with different thermal conductivity and temperature on a heat-adjusting zone radius, surrounding rock temperature field and wall temperature
Combining thermal insulation and support, this study aims to investigate the active thermal insulation roadway

Summary

Introduction

Deep mining of underground engineering is normalised and the thermal environment of mine, caused by high ground temperature, restricts further excavation (Yi et al 2019; Xie et al 2012). Wu et al (2019) and Xu (2014) explored the geothermal geological characteristics of the Huainan Mining Area in Anhui, China. In this area, the geothermal gradient is between 1.00 and 4.00 °C/hm, the average is 2.80 °C/hm. The average geothermal temperature is 29.96 °C for the burial depth of - 500 m, 41.84 °C for - 1000 m, and 69.62 °C for - 2000 m. It can be seen that the geothermal temperature gradually increases with the increase of burial depth. The control of heat, released from roadway surrounding rock, was considered as a sensitive matter to be solved and discussed urgently in the future

Objectives

Methods

Findings

Conclusion