報告書番号

M04002

タイトル（和文）

ガスタービン高温部品を対象とした伝熱流動数値解析 -第6報 起動／停止時における1300℃級初段動翼温度の過渡解析-

タイトル（英文）

Numerical Analysis of Heat Transfer for Gas Turbine Hot-gas-path Parts - The 6th report Transient Analysis of 1300 ℃ class First Stage Rotor Blade Temerature in Startup and Shutdown-

概要 （図表や脚注は「報告書全文」に掲載しております）

1300℃級ガスタービン(以下 GT)初段動翼を対象に、既報告で開発した翼温度の連成伝熱解析方法を応用して、実測が困難なGTの起動／停止時における翼温度分布を解析した。その結果、翼温度は、点火直後の急激なガス温度上昇により前・後縁および翼端側で大きく変化すること、負荷50％以上の運転時には分布の変化が小さいことなど、1100℃級GT初段動翼と同様の傾向を示した。一方で、冷却性能は、1100℃級GT初段動翼に比較して高く、点火直後の運転条件の変化に対しても、翼温度の応答が速いことが確認された。本解析結果により、寿命評価のための熱応力／クリープ解析が可能となった。また、負荷50％以上の運転状態では、翼外面平均熱伝達率は、翼まわりガスのレイノルズ数と高い相関があることがわかった。この相関を利用して、翼構造部の熱伝導解析により翼温度分布を推定した結果、連成伝熱解析結果と良好に一致し、翼温度分布を簡易に推定できる可能性が示された。

概要 （英文）

Three-dimensional numerical analyses of transient conjugate heat transfer of the first stage rotor blade in startup and shutdown operations of a 1300 Celsius degree class gas turbine were conducted in order to contribute to life assessment of the blade. The present conjugate heat transfer calculation is composed of convective heat transfer analysis around the blade and thermal conduction analysis in the blade material with one-dimensional thermo-flow calculation of the internal cooling in rib-roughened passages. Characteristic diagrams of startup and shutdown operations simulating an actual gas turbine in the combined-cycle plant were used for the numerical conditions. The present conjugate heat transfer calculations have been able to predict variations of the temperature distribution of the blade in the startup and shutdown processes that are difficult to measure in the actual machine. The temperature distribution of the blade remained similar in the operation over half load, and after ignition in the no-load conditions, local temperature markedly changed owing to unsteadiness of the heat conduction inside the blade. These general features of the predicted variations of the blade temperature were similar to those of the 1100 Celsius degree class gas turbine blade. Higher cooling performance of the 1300 Celsius class blade was verified than the 1100 Celsius class blade. The present predictions of the transient distributions of the blade temperature make it possible to put the analytical life assessment of the gas turbine blade into practice. Averaged heat transfer coefficient on the blade outer wall is well correlated with Reynolds number of gas flow around the blade under operations over half load. Estimated temperature distribution by thermal conduction analysis using this correlation of heat transfer is in good agreement with the conjugate heat transfer calculation. That gives probability that simplified analysis estimates the blade temperature faster.

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