Transcripción del resumen del autor. One of the challenges in controlling an underground coal mine fire is that it is fully sealed with limited information available through gas sampling. Most of previous works look at the fuel content of the mixture, or the explosibility. Here we are proposing a progress variable to check both fuel and oxygen for diagnosing what is the status of fire after sealing, and when the sealed atmosphere is explosive if a leaking is allowed. In essence, the flammability problem of mine gases is a mixture problem of multiple fuels, with carbon dioxide as the diluent, in an oxygen-modified air [ 1]. In order to determine the status of a sealed fire, a progress variable, heating/quenching ratio, is proposed as the completion between heating and quenching, whereas heating can be oxygen-based or fuel-based.

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