温泉湧出を伴う高温坑道内の気流の熱収支について

抄録

In the Toyoha mine the ground temperature is very high owing to hot mineral water found in the ground. Several veins bearing zinc and lead ores have been mined down to the depth of 300m from the level of the main entry. Since 1974, the 450m level of Tajima vein has been developed by driving a drift, where the rock emperature is from 80 to 90°C.
To obtain fundamental data for designing economical cooling, the heat balance in the drift was investigated by several measurements in August of 1974 and 1976, and continuously from August 1978 to July 1979. From these investigations the following informations were obtained.
The heat transfer through rock affected by hot mineral water to an air current is, against our expectation, not great, and is at most twice as much as a theoretical heat transfer through rock unaffected by hot mineral water. However in the case that an air current is in contact with hot water which flowed or seeped into the drift, a great heat transfer to the air current, sometimes ten times the theoretical heat transfer from rock unaffected by hot mineral water, will take place.
For effective cooling it is advisable to prevent inflow or seepage of hot mineral water, to prevent the air current from direct contact with hot water. and to use chilled water efficiently.