微渦輪引擎罐狀燃燒室應用氫氣／甲烷混合燃料之燃燒特性分析

Analysis of Combustion Performance of Hydrogen/Methane Blended Fuels Applied in a Can Combustor for a Micro Gas Turbine

劉錡融(Chi-Rong Liu) ； 石心怡(Hsin-Yi Shih)

《燃燒季刊》 80期 (2013/02) Pp. 19-38

https://doi.org/10.30041/CQ.201302_(80).0003

摘要

本研究以數值模擬的方式探討微渦輪引擎罐狀燃燒室應用氫氣／甲烷混合燃料之燃燒特性，此模型乃使用商用熱流分析軟體STAR-CD，進行三維可壓縮k-ε紊流流場分析並搭配PPDF（Presumed Probability Density Function）化學反應模型。分析結果包括火焰結構、溫度分布、主要物種分布及其汙染排放特性等。在參數研究方面，改變燃料噴嘴速度從20 m/s 至60 m/s，氫氣的比例從0 %至90 %（Mole Fraction）。當固定燃料噴嘴速度及燃料質量流率時， 整體當量比（Equivalence Ratio）及熱輸入（Heat Input）會隨氫氣在混合燃料中佔有之比例上升而增加，同時添加氫氣燃燒會使燃燒筒內溫度升高；且隨著氫氣在混合燃料中佔有之比例提高，高溫火焰會逐漸移動到燃燒筒中段，致使燃燒筒尾段溫度增加。若燃料質量流率隨氫含量增加而下降，其高溫火焰能在較低整體當量比下穩定駐焰且氮氧化物排放量降低。研究並分析相關燃燒室性能，包括燃燒室火焰結構、冷卻、溫度型樣（Pattern Factor）、以及汙染排放等問題，提供微渦輪引擎應用含氫燃料之改善方案。

關鍵字

氣渦輪引擎燃燒 ； 氫氣／甲烷混合燃料 ； 微渦輪引擎

並列摘要

Due to the shortage of hydrocarbon fuels and the demands of greenhouse gas emission reduction, hydrogen or hydrogen/hydrocarbon blended fuel has beenconsidered or used as one of the most promising clean fuels in the applications of engines. To better understand the combustion performance by using hydrogen/methane blended fuels for a micro gas turbine, the combustion characteristics of a can type combustor has been modeled and the effects of hydrogen enrichment were investigated. The simulations were performed using the commercial code STAR-CD, in which the three-dimension compressible k-ε turbulent flow model and presumed probability density function for chemical reaction between methane/hydrogen/air mixtures were used. The results showed the detailed flame structures including the flow fields, distributions of flame temperature, major species and gas emissions. In the parametric studies, the injection velocities of hydrogen/methane blended fuel were varied from 60 m/s to 20 m/s, and the percentage of hydrogen was from 0% to 90% in mole fraction. At a constant fuel supply rate, equivalence ratio and heat input increase with fuel inlet velocity and hydrogen percentage. The combustion flame temperature and exit gas temperature increase, consequently the combustion efficiency. If the fuel supply rate decreases with the increase of hydrogen percentage, the flame could be stable at lean condition and NOx emission would be decreased. Further investigations of the combustor performance were made, including pattern factor, hot spots at exit, poor cooling locations, and pollutant emissions, to improve the combustor design for the micro gas turbine engine with hydrogen/methane blended fuel as an alternative fuel.

並列關鍵字

Gas turbine combustion ； hydrogen/methane blended fuels ； microturbine