合成气稀释扩散燃烧实验研究

发布时间：2018-05-29 07:40

  本文选题：合成气 + 层流扩散火焰　； 参考：《南京师范大学》2017年硕士论文

【摘要】：合成气可由煤、生物质、废弃物在汽化炉中气化,然后净化获得,是一种清洁燃料,具有广阔的应用前景。但不同原料得到的合成气组分比较复杂、热值较低、燃烧稳定性差,给它的实际应用带来了很多困难,其中NOx排放控制就是重要问题之一。在气体燃料中添加稀释剂是抑制NOx生成的一种有效方法,但相关实验研究仍有待进一步完善。本文基于气体燃料稀释燃烧技术,以同向轴对称层流扩散火焰为对象,采用实验研究方法,就添加稀释剂对合成气/空气扩散火焰中NO和CO污染物形成的影响进行了研究。建立气体燃料扩散燃烧实验系统,采用实验方法研究了不同碳氢比的合成气火焰在不同稀释剂种类、稀释比和稀释剂添加侧条件下NO和CO的排放特性和变化规律,记录了合成气燃烧过程中火焰形貌的变化情况。实验发现随着H2/CO比的减小纯合成气燃烧的火焰颜色由浅变深,由淡黄色变为淡蓝色,再由淡蓝色变为亮蓝色。火焰高度变高,宽度变窄,呈拉伸状。测量尾气中的污染物含量,发现实验范围内的三种稀释剂均可以有效降低NO及CO的生成量。NO的排放指数EINO随合成气碳氢比的增大而单调增加,CO的排放指数EIco随碳氢比的增大而减小。对N2、Ar及CO2三种稀释均有EINO (R) EINO (Y)成立,对N2、CO2两种稀释剂有EIco (Y) EIco (R)成立。另外,EINo及EIco随稀释比的变化规律随稀释剂种类、稀释剂添加侧的不同而不同。三种稀释剂对NO的减排效果存在如下关系:CO2 N2 Ar纯合成气,即CO2效果最好,N2次之,Ar效果最差,但都比不加稀释剂时的效果要好;类似地,对CO而言存在如下关系:N2≈ArCO2纯合成气。本文探究了不同条件下合成气的扩散燃烧特性,分析了 H2/CO比、稀释剂种类、稀释比、稀释剂添加侧等因素对合成气燃烧特性的影响,揭示了合成气燃烧过程中NOx和CO的排放规律,获得促进合成气稳定燃烧和低污染物排放的有效方法。相关实验数据可为实际燃烧设备的设计和优化提供指导,具有一定的工程应用价值。
[Abstract]:Syngas can be gasified from coal, biomass and waste in vaporization furnace and then purified. It is a clean fuel and has a broad application prospect. However, the composition of syngas from different feedstocks is complex, the calorific value is low, and the combustion stability is poor, which brings a lot of difficulties to its practical application, among which NOx emission control is one of the important problems. The addition of diluents in gaseous fuels is an effective method to inhibit the formation of NOx, but the related experimental studies need to be further improved. Based on the gas fuel dilution combustion technology, the effects of diluent addition on the formation of no and CO pollutants in syngas / air diffusion flame were studied by means of experimental study on the coaxial symmetrical laminar diffusion flame. The experimental system of gaseous fuel diffusion combustion was established. The emission characteristics and changes of no and CO in syngas flame with different hydrocarbon ratios under different diluents, dilution ratio and diluent side were studied. The changes of flame morphology during syngas combustion were recorded. It is found that the flame color of pure syngas combustion changes from light to deep, from light yellow to light blue, and then from light blue to bright blue with the decrease of H2/CO ratio. The flame height becomes higher, the width becomes narrow, and the flame is stretched. To measure the amount of pollutants in the tail gas, It is found that the emission index EINO of no and CO can be effectively reduced by the three diluents in the range of experiment. The emission index EIco of CO decreases with the increase of the ratio of carbon to hydrogen in syngas with the increase of the ratio of carbon to hydrogen. For N _ 2N _ 2 ar and CO2, EINO (R) EINO (Y) was established, and for N _ (2) O _ (2) O _ (2) diluent, EIco (Y) EIco (R) was established. In addition, the variation of EINO and EIco with dilution ratio varies with the type of diluent and the side of diluent. The effect of the three diluents on the emission reduction of no is related to the following: the effect of CO2 is the best in N 2, followed by N 2, but is better than that in the absence of diluent; similarly, For CO, the relationship exists as follows: n _ 2 鈮，

本文编号：1950053