Application of liquid CO2 conveying technology for fire control in goaf
This paper aims to design a desirable method to inject liquid CO2 directly to the deep underground via long-distance pipe. To this end, a liquid CO2 transport technology was put forward and applied to cool down the fire area in an underground coal mine. To ensure the liquid phase of CO2, the pipe pressure was controlled by adjusting the flows at the inlet and outlet of the storage tank, and the pressure, flow and temperature parameters were monitored at several key positions. Through the theoretical analysis and case study, the proposed liquid CO2 transport system was proved as feasible under the control of pipe pressure. The results show that the pressure of 2.2MPa is applicable for liquid CO2 transport system, and the pressure change in the pipe hinges on the pressure at liquid CO2 tank, vertical depth and pipe length. By this system, the temperature of liquid CO2 could be controlled as low as -15oC. The research findings provide valuable insights on the application of liquid CO2 in fire control in underground coal mines.
liquid CO2, transport system, coal spontaneous combustion, fire control, long-distance pipe, large vertical depth
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