針對日益受到重視的低熱值氣化合成氣於微型氣渦輪引擎的應用所引起的問題，吾人特別提出旁通式氣化合成氣觸媒駐焰燃燒室的概念，利用並行非觸媒旁通管道預熱並旁通部分燃料氣體，而與經過觸媒管道的高溫氣體迅速混合點燃穩駐於下游氣相反應區並持續燃燒釋放熱量，燃燒室中的觸媒用來點燃以及提高氣體溫度以穩駐下游氣相燃燒。吾人首先利用數值模擬的方法證實旁通觸媒燃燒室的可行性，同時使用單管旁通式觸媒燃燒室也觀察到下游氣相反應區。接著觀察不同燃料成分與流體速度的差異，量測觸媒壁面與出口溫度，更進一步利用化學發光影像技術，觀察OH的分布情形。在結果中發現氣化合成氣中的H2先被觸媒表面反應點燃，接著引起靠近壁面的CO氣相反應並且延續到下游。在足夠的觸媒反應熱下，旁通比是決定穩駐觸媒出口下游勻相氣相反應之重要因素，大部分氣化合成氣中之CO是在此反應中進行氧化反應。另外，隨著燃料中H2比例的增加，不僅壁面溫度會增加同時也會幫助下游氣相反應區穩駐。

In view of the increasing global concern of the depletion of the convenient fossil fuels, combustion of low heating value fuels attracts intensive attention of the research community. For efficient and clean applications, syngas from gasified low heating value fuels are used for power generation in catalytic gas turbines. The contradicting problems of temperature limitation due to catalyst sintering and the gas turbine efficiency lead to greatly sacrifice in the overall efficiency in the current catalytic gas turbines. In the present study, we propose the concept of a bypass-catalytic-stabilization combustor for use in the miniature syngas gas turbines. By placing the non-catalyst bypass channels next to the catalyst channel, some of the fuel-air mixture is bypassed and preheated in the channel and the preheated mixture mixes with the hot gas from the catalytic channel and ignites and burns stably in the downstream gas-phase reaction zone. In this study, firstly, numerical simulations are performed in a syngas catalytic miniature gas turbine combustor with various parameters of bypass ratios and pressure ratios to evaluate the feasibility of the concept. Secondly, the catalytic reaction and gas-phase combustion characteristics are observed by using the bypassed single catalytic channel combustor. Temperature measurements of the catalytic surface and gas-phase reaction zone under different velocities and fuel compositions are performed. The distributions of OH radicals in the reaction zones are measured by using chemiluminescence-imaging techniques. The results show that H2 of the syngas can first be ignited by surface catalytic reaction at the channel entrance and enhance the gas-phase reaction of CO near the wall and downstream. Bypass ratio dominates the supplies of combustible mixture downstream of the catalyst outlet to stabilize the following gas phase reactions in the homogeneous gas-phase reaction zone when the energy release from catalyst and bypass channels is sufficient. CO component of the syngas is mostly consumed in the gas-phase reaction in this region. In addition, we observe that not only the temperature of catalytic surface is increased but also the gas-phase reaction is enhanced with increasing the content of H2.

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