Considerations Concerning the Stream of Heat Transferred from Rock Mass Into Mine Ventilation Air and the Utilization of this Heat by Means of Air Cooling Installation / Úvaha Týkající Se Přestupu Tepla Z Horninového Masívu Do Důlního Ovzduší A Použití Chladicích Zařízení K Využití Tohoto Tepla

Abstract

This paper deals with the feasibility of utilization of the heat carried away with the air stream ventilating a mine after closing down mining operations. The problem is that, although the temperature of air flowing underground is rather high (above 35 o C), the air temperature at the surface level drops to about 25 o C. For that reason it was proposed to cool down the hot air underground and to transport the hot water from cooling machines to the surface level. However, such a solution is not realistic in closed-down mines. So, another idea was considered consisting in exploiting the thermal energy of the exhaust air stream in functioning mines. Further the cooling potential of Polish mines was surveyed. It emerged that for the mines with an active cooling potential in the range of a couple of MW it can be economically viable to transfer the gained thermal energy released due to surface condensation and to use that energy for communal heating. AbstraktČlánek se zabývá možnostmi využití tepla, které je odváděno důlním ovzduším na povrch po ukončení dobývání. I když teplota tohoto ovzduší v dole je poměrně vysoká (více jak 35°C), tak po výstupu na povrch se tato teplota snižuje na cca 25°C. Proto bylo navrženo, aby teplé ovzduší bylo schlazováno v dole a na povrch by se odváděla teplá voda pocházející z chladících zařízení. Toto řešení je ale málo reálné v případě dolu, kde již byla těžba ukončena. Proto další návrh se týká využití tepla obsaženého v použitém důlním ovzduší činných dolů. Byl vyhodnocen chladící potenciál polských kamenouhelných dolů. Z této analýzy vyplývá, že v dolech s činným chladícím potenciálem řádově několika MW, může být ekonomicky výhodný záměr spojený s odváděním kondenzačního tepla, pocházejícího z chladících zařízení, na povrch a jeho využití pro vytápění.

Remarks on Heat Emission during Operation in Hot Rock Mass and on Possibilities of Its Use

“…(Knechtel, 2011). However, opposed to the data contained in work (Knechtel, 2011), the original temperature of rock is variable both along the roadway as well as along the longwall face and moreover, due to the installation of chillers in workings, the air temperature changes stepwise which affects the temperature changes of the surrounding rock mass. Hence, rock temperature isolines in the function of distance from the side wall are more irregular.…”

“…This water can however be mixed with water of a temperature of 125 0 C, which powers the "warm-water" absorption chillers, being the second stage of cooling cold water. In works (Knechtel, , 2011 it was proposed that hot water from condensers might be used on the surface for municipal purposes. In this case, however, a network of insulated pipelines distributing the water to users is necessary.…”

“…The longwall operation lasted six months. The amount of heat which at that time was emitted by the rock mass into the area is much greater than the corresponding amount of heat, as referred to in the work (Knechtel, 2011). In work (Knechtel, 2011) a similar mining department is discussed, but the original temperature of rock is of about 8 0 C lower as well as the intensity of the area ventilation.…”

“…Examining the process of rock mass cooling, similarly to works (Knechtel, , 2011, 50-metre sections of the working have been discussed. In the case of longwall workings, these were 30-metre sections.…”