【作者】 李昊；

【导师】 岑可法； 程乐鸣； 倪明江；

【作者基本信息】 浙江大学 ， 工程热物理， 2004， 硕士

【摘要】 往复式多孔介质燃烧在提高燃烧效率、扩展可燃极限、节约燃料、改善环境以及处理各类垃圾和废弃物方面与其他燃烧技术相比具有优越性，是一种燃烧效率高、污染排放量低的燃烧技术。这种燃烧技术在强化燃烧和排放控制方面是一种比较有效、实用的燃烧方法。本文主要对往复式多孔介质燃器进行了试验研究。 本文的研究工作分为四个部分。第一部分对往复式多孔介质燃烧技术的研究发展状况进行了概述。在介绍往复式多孔介质燃烧中涉及到的两个重要的概念—超绝热燃烧、多孔介质燃烧的基础上，讨论了往复式多孔介质燃烧在基础研究和应用研究方面目前的研究现状，为本研究的进行打下基础。 第二部分主要内容是往复式多孔介质燃器的冷态阻力特性的试验研究。在前述综述的基础上，对往复式多孔介质燃器进行了冷态实验研究，主要研究了空截面流速和多孔介质厚度两个影响因素对燃烧器稳定时间以及阻力特性的影响，并由此建立了简单的数学模型。结果表明，在其他条件不变的情况下，往复式多孔介质燃烧器的压差ΔP与空截面流速的平方u²基本成正比关系，与多孔介质厚度h呈线性增大关系；多孔介质厚度h以及空截面流速u对燃烧器的流动稳定时间t₀影响很小；实验结果与数学模型得到了较好的吻合。 为了研究燃烧器的燃烧特性，进行了往复式多孔介质燃烧器的热态实验研究，这是本文第三部分的主要工作。试验研究了当量比、切换半周期、空截面流速三个影响参数对温度分布的影响规律，以及燃烧器污染物排放的特点。结果表明，当量比φ＜1的时候，随着φ的减小，燃烧器内多孔介质的温度也随着减小，燃烧火焰的中心逐步上移，温度最大值也随着减小；在切换半周期和当量比一定的情况下，随着空截面流速的增加，燃烧器两侧的温度也随着增大，燃烧器的温度趋于等同值的趋势增加。在其他条件不变的条件下，切换半周期越长，出口温度越高；随着切换半周期增大，测点温差也随着增大，并且越是距离火焰中心近的测点，其温差的变化越大；对往复式燃烧和单个燃烧进行比较，往复式燃烧的温度分布更均匀，排烟温度更低，污染物排放更低。 第四部分在理论上对往复式多孔介质燃烧器进行探讨，确定了燃烧过程的主要的特点，建立了简单的数学模型。计算并分析了当量比、空截面流速、散热系数对温度分布的影响，将计算结果与试验结果进行了对比。结果发现，在沿轴浙江大学硕士学位论文摘要向方向上，呈现出M型的温度分布。随着当量比的增加，整体的温度升高;随着空截面流速的增加，整体的温度升高;散热系数增大，整体的温度下降;计算结果和试验结果的吻合较好，证明模型一定的正确性。更多还原

【Abstract】 A novel combustion manner, which is called porous media combustion with a reciprocating flow system, has been presented with its predominant advantages of high thermal efficiency, stable combustion, broad combustion limits and low pollutant emissions. It became one of the most efficient and practical combustion manner in combustion strengthening and emissions control. Experimental and theoretical approaches in porous media combustor with a reciprocating flow system are presented in this paper.The work done by this article mainly includes four parts: first, the research development of combustion in porous media with a reciprocating flow system is summarized. Two important concepts: superadiabatic combustion and porous media combustion was introduced. Then, the detailed introductions on both mechanical and application research on porous media combustion with a reciprocating flow system are presented.Second, cold experimental tests were carried out, and a simple mathematic model was developed based on the experimental results. The effects of the superficial velocity and porous media thickness on the pressure drop and the steady time of the burner were analyzed. The calculation results from the model were compared with the experimental data. The results showed that keeping other parameters constant, the differential pressure AP in the burner is in direct ratio with the square of the superficial velocity and the porous media thickness. However, the steady time is independent of them. The calculation results are in good agreement with the experimental ones.Third, the thermal state experimental research was carried out in the porous media burner with a reciprocating flow system. The effects of various equivalent ratios, circulating cycle time and gas flow velocity on the temperature distribution and pollutant emission are analyzed. The main results are: The measuring points temperature decreases, the flame center shifts up, and the top temperature of the burner decreases as functions of equivalent ratio , during <1; the all measuring points temperature increases as the superficial velocity increase; when the circulating cycle time increases, the export temperature and measuring points temperature of the burner increases, and a large change of the temperature can be found near the flame center; Compared with simple porous media burner, much more homogeneous temperature distribution and lower exit flue temperature can be obtained using the reciprocating porous media burner.Forth, comprehensively describing the burner with a reciprocating flow system in the porous media, we found the character in the course of the burning and constitute the mathematics modle of the burner. We compute and analysis the infection of the equivalent ratio, gas flow velocity and heat loss coefficient on the temperature distribution.and compare the results with the experiment and the others. We found that the temperature distribution is like M shape along the axes of the burner. The monolithic temperature of the burner increased with the increase of the equivalent ratio, gas flow velocity, but decease with the increase of the heat loss coefficient. Calculating results accord with the experimental results.更多还原