Abstract:

The huge energy consumption is the main problem in the mining of mineral resources in China.In recent years，due to the continuous consumption of underground mineral resources，deep mining operations are becoming more and more common.Increasing the effective ventilation of mines is critical to saving energy consumption.The high-temperature environment of deep mines stores a large amount of heat energy，and if it can be comprehensively utilized，it will produce huge benefits.In recent years，domestic and foreign researches on the absorption，storage，and transformation of thermal energy have yielded rich results.Based on this，the temperature difference formed between the high temperature of the deep well and the surface temperature can be used as an energy source，and the temperature difference can be used as a ventilation power can improve the effective ventilation of deep mines.This paper starts with the theoretical analysis, and analyzes the state change of ideal gas in thermal environment.Then the feasibility of temperature difference energy for improving air volume is demonstrated.Secondly, a deep mine model was established based on Ventsim three-dimensional ventilation software, and the heat energy stored in deep mines was simulated by setting a linear heat source. Finally,the representative necessary ventilation roadway in mine structure, such as main air inlet shaft, main return shaft and horizontal tunneling roadway, is selected as the research object to analyze the influence of different temperature setting and layout of linear heat source on the effective ventilation volume of mine.The specific scheme is as follows:\mathrm{①}The linear heat source power was increased from 1 000 W/m to 3 500 W/m incremented by 500 W/m, so as to study the change of effective mine ventilation under the action of linear heat source at different temperatures.\mathrm{②}The linear heat source was set to a range of 1 000 W/m to 4 000 W/m, and the linear heat source was successively distributed according to the increasing of 1 000 W/m and 500 W/m in the same section of return air shaft, to observe the influence of the linear heat source with different power decreasing gradient distribution on the effective ventilation volume of the mine. The results of the study are as follows: In mine laneway when the dry bulb temperature at 35~48 ℃, the temperature rise of the linear heat source is linear positively correlated with the increase of the effective mine air volume. For the horizontal roadway with a small air volume basis value at the bottom of the mine, the linear heat source in the return air shaft does not significantly improve its effective air volume.When the temperature difference range of the linear heat source is the same, the reasonable setting of small amplitude and multiple intervals of the temperature difference can generate effective pressure drop, improve the dynamic effect of the temperature difference energy, and thus improve the effective ventilation volume. And the scheme is more economical and can improve the utilization rate of temperature difference energy.

Key words: linear heat source, high temperature of deep well, effective ventilation, ventilation optimization, Ventsim, numerical simulation, temperature difference energy