Effect Of Equivalent Ratio (ER) On the Flow and Combustion Characteristics in A Typical Underground Coal Gasification (UCG) Cavity

Underground Coal Gasification (UCG) is thought to be the most favourable clean coal technology option from geological-engineering-environmental viewpoint (less polluting and high efficiency) for extracting energy without digging it out or burning on surface. UCG process requires only injecting oxidizing agent (O2 air with steam) as raw material, into buried seam, at an effective ratio which regulates performance of gasification. This study aims evaluate influence equivalent (ER) flow combustion characteristics in a typical half tear-drop shape cavity generally formed during process. A modeling software, Ansys FLUENT used construct 3-D model solve problems cavity. The boundary conditions are- (i) mass-flow-inlet passing oxidizer (in this case, air) cavity, (ii) fuel-inlet where volatiles are originated (iii) pressure-outlet flowing product Syngas steady-state simulation has been run using k-? turbulence model. mass rate varied according 0.16, 0.33, 0.49 0.82, while fuel was fixed. optimal condition ER identified through observing characteristics, looked apparently stable 0.33. In general, circulation mainly takes place around ash-rubble pile. temperature zone found air-releasing point injection pipe could practically useful identify one vital controlling factors gasification (i.e., impact gas characteristics) might become cost-effective solution advance commencement any physical operation.