环形先进旋涡燃烧室流动、燃烧和污染物排放特性

Flow，Combustion and Emission Characteristics of Annular Advanced Vortex Combustor

关键词:  环形先进旋涡燃烧室  流动特性  三对钝体  粒子图像测速技术

Key words:  Annular advanced vortex combustor  Characteristics of the flow  Three pairs of bluff bodies  Particle image velocimetry

摘要:

为了给先进旋涡燃烧技术实际应用提供理论依据，采用实验和数值模拟相结合方法，对环形先进旋涡燃烧室流动和燃烧特性开展研究。首先采用粒子图像测速技术，对三对钝体布置先进旋涡燃烧室，进行冷态流动特性实验。在此基础上，对燃氢螺旋布置18对钝体的环形先进旋涡燃烧室的燃烧特性，开展了数值模拟。结果表明:(1)有后钝体存在，可以抑制气流在前钝体后面形成旋涡脱落，从而减小了流通气流的流动阻力；(2)在凹腔喷射气流的作用下，相对于无喷射条件下凹腔内形成的旋涡结构拉长，而且占据了整个凹腔；(3)随着主气流当量比增加，流经环形AVC气流在前、后钝体间的凹腔内的旋涡结构更加趋于对称，出口平均温度、燃烧效率、NO_x质量分数和总压损失系数也增大，出口温度分布系数减小。(4)喷射角在45°范围内，随着喷射角的增加，燃烧效率和出口平均温度增加，NO_x质量分数、总压损失系数和出口温度分布系数减小。

Abstract:

To provide a theoretical basis for the practical application of advanced vortex combustor (AVC)，a combined experimental and computational study was carried out about the flow and combustion characteristics of an annular AVC. In order to simulate the periodic boundary conditions of annular AVC，an experimental study was carried out on the flow characteristics of an AVC arranged three pairs of blunt bodies under the non-reacting flow condition using particle image velocimetry (PIV) technology. On this basis，a numerical simulation study was conducted to an annular AVC spirally arranged 18 pairs of blunt bodies between the two cylinders. The results show: (1) After-body can restrain the formation of vortex shedding of the flow through the fore-body，thereby reduces the flow resistance of the flow. (2) The vortex structure stretches and occupies the entire cavity under the action of the jet flow in the cavity，comparing with no injection condition. (3) With increasing the equivalence ratio，the vortex structure generated by the flow through the annular AVC in the cavity between the fore-body and after-body tends to be more symmetrical，the average temperature at the outlet，the combustion efficiency，the NO_x emission，the coefficient of the total pressure loss of the annular AVC increase，and the temperature distribution coefficient at the outlet decreases. (4) In the range of 45° injection angle in the cavity，with the injection angle increasing，the average temperature at the outlet and the combustion efficiency increase，the NO_x emission，the coefficient of the total pressure loss and the temperature distribution coefficient at the outlet decrease.