報告書番号

W96007

タイトル（和文）

水素燃焼タービンの基礎燃焼特性－水素，酸素ならびに活性化学種の生成・分解特性についての解析的検討

タイトル（英文）

FUNDAMENTAL STUDY ON COMBUSTION CHARACTERISTICS OF GAS TURBINE USING OXYGEN-HYDROGEN -NUMERICAL ANALYSIS OF FORMATION/DESTRUCTION CHARACTERISTICS OF HYDROGEN, OXYGEN AND RADICALS-

概要 （図表や脚注は「報告書全文」に掲載しております）

不活性ガス中において水素（Ｈ２）を酸素（Ｏ２）により燃焼させた場合の基本的な燃焼特性について平衡論ならびに反応動力学に基づく数値解析により検討し，以下のことを明らかにした。（１）Ｈ２，Ｏ２ならびに水蒸気の一部を予混合して燃焼器スワラーから供給し，残りの水蒸気をライナ部より段階的に供給して出口ガス温度を１７００度とする場合，燃焼器出口における残存Ｈ２，Ｏ２ならびに活性化学種（ＯＨ，Ｏ，Ｈ基の総和）がそれぞれ０．７ｖｏｌ％，０．３ｖｏｌ％ならびに０．３ｖｏｌ％程度と高い濃度で排出すると予想される。これは，従来行われてきた化学平衡論による計算で得られる値の約５倍に相当している。（２）Ｈ２・Ｏ２の量論比燃焼では火炎温度が高いこと，また，水蒸気は熱解離して燃焼反応を促進する効果があることなどから，バーナから供給する水蒸気量の配分を増加させても，燃焼反応は損なわれない。したがって，燃焼器壁面の冷却を考慮すると一次燃焼領域（バーナの近傍）に多量の水蒸気を供給し，火炎温度の上昇を抑制することが重要と考えられる。

概要 （英文）

WE STUDIED THE COMBUSTION GAS EMISSION CHARACTERISTICS OF AN OXYGEN/HYDROGEN GAS MIXTURE SHEATHED BY AN INERT GAS USING NUMERICAL ANALYSIS BASED ON EQUILIBRIUM THEORY. WE ALSO EXAMINED THE COMBUSTION CHARACTERISTICS OF THE MODEL COMBUSTORS USING REACTION KINETICS. THE RESULTS ARE SUMMARIZED AS FOLLOWS: (1)THE COMBUSTOR MODEL WAS BASED ON THE FOLLOWING ASSUMPTIONS:(1)THAT HYDROGEN, STOICHIOMETRIC OXYGEN AND A PORTION OF THE STEAM WERE PREMIXED AND FED TO A COMBUSTOR FROM THE SWIRLER, (2)THAT THE REMAINDER OF THE STEAM WAS FED IN FROM THE LINER IN STAGES, (3)THAT THE COMBUSTION GAS RESIDENCE TIME IN THE GASTURBINE COMBUSTOR WAS TENS OF MILLISECONDS, AND (4)THAT THE COMBUSTIONGAS TEMPERATURE AT THE EXIT OF THE COMBUSTOR WAS 1700DEGREE. OPERATINGTH E MODEL WITH THESE ASSUMPTIONS, THE EMISSIONS OF HYDROGEN, OXYGEN AND THE TOTAL QUANTITIES OF OH, O AND H RADICALS WERE HIGH, AT APPROXIMATELY 0.7%, 0.3% AND 0.3% RESPECTIVELY. THESE CONCENTRATIONS ARE FIVE TIMES GREATER THAN EXPECTED, BASED ON EQUILIBRIUM THEORY. (2)SINCE THE COMBUSTION GAS TEMPERATURE OF THE OXYGEN/HYDROGEN MIXTURE IN STOICHIOMETRIC RATIO IS HIGH AND THE THERMAL DISSOCIATION OF THE STEAM PROMOTES THECOMBUSTION REACTION AT A HIGH TEMPERATURE, THE COMBUSTION REACTION IS NOT RESTRAINED BY AN INCREASE IN THE STEAM CONTENT FED FROM THE SWIRLER. CONSIDERING THAT THE LINER WALL MUST BE COOLED, IT IS IMPORTANT THAT A LARGE PORTION OF THE STEAM IS FED FROM THE SWIRLER AND THAT THE COMBUSTION GAS TEMPERATURE IN THE PRIMARY COMBUSTION ZONE IS LOWERED.

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