Mining Institute, Ural Branch, Russian Academy of Sciences, Perm, Russia:

L. Yu. Levin, Deputy Director of Sciences, Doctor of Engineering Sciences, aerolog_lev@mail.ru
Yu. A. Klyukin, Leading Engineer
M. D. Popov, Engineer

AeroSfera Science and Production Association, Perm, Russia:

S. V. Butakov, Director

Development of air conditioning systems require to solve problem of a selection of the coolant which transfers heat from the air coolers to the evaporator of the refrigeration machine and from the condenser of one to the heat recovery units. To increase the reliability of the system and to avoid the possibility of freezing aqueous solutions of various chemical compounds, such as propylene glycol, ethylene glycol, calcium chloride salts and sodium chloride, as well as aqueous solutions of alcohol, can be used. An essential indicator in the operation of central air conditioning systems is the toxicity of the coolants. Therefore, in mine air conditioning systems water and aqueous solutions of propylene glycol of various concentrations can be used. This paper is a case study of thermal parameters of underground mine conditioning systems using two intermediate heat-transfer agents: water and 25% propylene glycol. The authors describe the positive effect exerted by heat capacity, thermal conduction, heat exchange factor and hydraulic characteristics of water on the resultant performance of mine air conditioning system and its materials consumption a compared with propylene glycol. In addition, propylene glycol has essentially lower temperature of crystallization as against water, which governs its use for cooling water down the temperature of water crystallization.

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