Economics of exhaust air heat recovery systems for mine ventilation

Abstract

Underground mining in cold regions of the world requires the heating of fresh air intake. On the other hand, exhaust air is usually discharged to the atmosphere at much greater temperatures than the ambient air. Using a medium such as water or glycol, heat can be extracted from the exhaust air and transferred to a desired location for use. In some mines, heat recovery could contribute to large energy savings especially with the increasing price of fossil fuels and electricity. This paper describes a computer software application developed in order to evaluate the feasibility of recovering heat from exhaust mine air. The software uses input data for a given mine site to obtain the cost benefits of installing an exhaust heat recovery system to heat the mine intake air during cold periods. There are two main components within the software; energy analysis of the system and capital cost estimation of the project. Assumptions and calculations performed within the software are briefly discussed. Several results of fictitious mine sites are presented.