気流による坑内冷却に関する研究 (第2報)
1955 年 71 巻 810 号 p. 747-752
詳細
1955 年 71 巻 810 号 p. 747-752
From a complementary study carried out on the heat transfer coefficient of underground airways, it is proved that the coefficient is proportional to a coefficient of friction and an air velocity. Taking this relation into account, a series of calculations have been executed on the temperature change of mine air current under various conditions by the approximate method. described in the preceding paper. These results are serviceable not only to get deta for the design of ventilati on in hot mines but also to derive some instructions about underground cooling.
Is is shown that there is a certain limit in underground cooling by means of ventilation, that the lower the thermal conductivity as well as the heat transfer coefficient, the more effective is the cooling, and that a smaller sectional area may not always be more effective in case the air quantity remains constant, whereas a greater velocity is of course preferable under a constant sectional area.
