HEMS technique for heat-harm control and geo-thermal utilization in deep mines

Abstract

With the increasing exploitation scope and intensity, the shallow resources would be exhausted in the future; and the deep mining will become an essential choice. In deep tunnel engineering, the heat-harm becomes one of the main barriers. Investigations on high temperature coal mine have been done in Northern China, with the constructing of three models of high temperature mines suffering heat-harm, at the Jiahe mine, Sanhejian mine and Zhangshuanglou mine. The domestic and abroad cooling technologies of the mine respectively are also summarized after comparatively analyzing the advantages and disadvantages of each technology. Finally, we find that the high temperature exchange machinery system (HEMS) technology that use mine discharge as the cold source, is excellent to heat-harm control in deep mines. Taking the Jiahe coal mine as an example, we systematically introduce this technology by disposing three main workstations. HEMS technology with its operations and functions in different exploitation levels are accomplished, including the extraction of refrigerating output, the transportation of chilled water by closed circulation line, the decompression of circulation lines and equipment by pressure transformation machine, and the heat exchange and cooling of workplace by heat exchange between wind stream and the chilled water. The exchanged heat source from the workplace is taken to ground heating by the circulating water which acts as a carrier. It shows that the HEMS-technology benefit in environment protection and emission reduction. Results of this project illustrate that it is efficient in heat-harm control with the temperature decrease of the workplace down to 26–29 °C, and being 4–6 °C lower than the original, and the relative humidity 5 %–15 % lower than before. It greatly improves the working environment of underground workplace suffering heat-harm of high temperature and high humidity. In addition, by the extracting of deep geothermal energy, ground fired boiler for heating has been replaced, reducing environmental pollution. This technology is worth generalization in deep mines and related fields.