The development of integrated coal gasification combined cycle (IGCC) systems ensures higher thermal efficiency and environmentally sound options for supplying future coal utilizing power generation needs. The Japanese government and electric power industries in Japan promoted research and development of an IGCC system using an air-blown entrained-flow coal gasifier. On the other hand, Europe and the United States are now developing the oxygen-blown IGCC demonstration plants. Gasified coal fuel produced in an oxygen-blown entrained-flow coal gasifier, has a calorific value of 8–13 MJ/m3 which is only 1/5–1/3 that of natural gas. However, the flame temperature of medium-Btu gasified coal fuel is higher than that of natural gas and so production from nitrogen fixation is expected to increase significantly. In the oxygen-blown IGCC, a surplus nitrogen produced in the air-separation unit (ASU) is premixed with gasified coal fuel (medium-Btu fuel) and injected into the combustor, to reduce thermal- production and to recover the power used for the ASU. In this case, the power to compress nitrogen increases. Low emission technology which is capable of decreasing the power to compress nitrogen is a significant advance in gas turbine development with an oxygen-blown IGCC system. Analyses confirmed that the thermal efficiency of the plant improved by approximately 0.3% (absolute) by means of nitrogen direct injection into the combustor, compared with a case where nitrogen is premixed with gasified coal fuel before injection into the combustor. In this study, based on the fundamental test results using a small diffusion burner and a model combustor, we designed the combustor in which the nitrogen injection nozzles arranged on the burner were combined with the lean combustion technique for low- emission. In this way, we could reduce the high-temperature region, where originated the thermal- production, near the burner positively. And then, a combustor with a swirling nitrogen injection function used for a gas turbine, was designed and constructed, and its performance was evaluated under pressurized conditions of actual operations using a simulated gasified coal fuel. From the combustion test results, the thermal- emission decreased under 11 ppm (corrected at 16% ), combustion efficiency was higher than 99.9% at any gas turbine load. Moreover, there was different effects of pressure on thermal- emission in medium-Btu fuel fired combustor from the case of a natural gas fired combustor.
Development of Low Combustion Technology in Medium-Btu Fueled 1300°C-Class Gas Turbine Combustor in an Integrated Coal Gasification Combined Cycle
e-mail: takeharu@criepi.denken.or.jp
Contributed by the International Gas Turbine Institute (IGTI) of THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS for publication in the ASME JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Paper presented at the International Gas Turbine and Aeroengine Congress and Exhibition, Munich, Germany, May 8–11, 2000; Paper 2000-GT-028. Manuscript received by IGTI, Nov. 1999; final revision received by ASME Headquarters, Feb. 2000. Associate Editor: D. R. Ballal.
Hasegawa, T., Hisamatsu , T., Katsuki , Y., Sato, M., Koizumi , H., Hayashi , A., and Kobayashi, N. (December 27, 2002). "Development of Low Combustion Technology in Medium-Btu Fueled 1300°C-Class Gas Turbine Combustor in an Integrated Coal Gasification Combined Cycle ." ASME. J. Eng. Gas Turbines Power. January 2003; 125(1): 1–10. https://doi.org/10.1115/1.1496772
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