水泥窑用富氧低NO_x燃烧器数值模拟与试验研究

发布时间：2018-03-07 18:10

  本文选题：回转窑　切入点：NOx　出处：《西南科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：水泥窑煤粉燃烧器是水泥熟料煅烧的重要设备,其性能的优劣以及操作参数的改变都会对熟料的产量、质量以及烧成热耗产生影响。富氧燃烧技术的出现为水泥回转窑节能降耗提供了助力,富氧燃烧技术不仅能提高熟料煅烧温度、提高熟料产量及质量,还能够节约燃料,减少有害气体(主要为NOx)的排放,减少大气污染。富氧燃烧作为一种新的燃烧技术应用在水泥回转窑虽已有少量研究,但将富氧燃烧技术与水泥窑用煤粉燃烧器相结合的研究还未见诸报道。本论文在国内外燃烧器及富氧燃烧技术研究现状的基础上,进行归纳、总结、创新,设计出一种将富氧燃烧技术应用于一次风中的富氧低NOx燃烧器。借助仿真软件Fluent对设计工况下的流场进行了数值模拟研究,详细分析了窑内的速度场、温度场及NOx的浓度分布,数值计算结果比较准确的反应了回转窑内部流场的分布规律。同时,重点研究了提高一次风中氧气浓度对回转窑内温度场及NOx浓度分布的影响,得出当氧气浓度27%左右时节能降NOx效果较为显著。随后,数值模拟主要研究了调整燃烧器操作参数对回转窑内速度场、温度场及NOx浓度分布的影响。为了验证模拟结果与实际工况的一致性,运用模拟计算结论对国内某1000T/D水泥回转窑所用三通道燃烧器进行改造的同时购置安装了膜法制氧设备。设备运行后一次风中氧气浓度达到26.8%,并分别对通入富氧前后的烧成系统进行了热工检测,通过标定数据的对比分析得出,通入富氧后至少提高了火焰温度120℃、熟料产量提高15%、熟料烧成热耗降低9.53%,并实现了NOx的减排。本文对所设计富氧低NOx燃烧器的数值模拟研究及生产实验,为水泥行业运用富氧燃烧技术实现节能降耗、减排NOx提供了指导,同时也为推进整个水泥行业技术进步提供了参考。
[Abstract]:Cement kiln pulverized coal burner is an important equipment for cement clinker calcination. The quality of its performance and the change of operating parameters will affect the output of clinker. The appearance of oxygen-enriched combustion technology can help to save energy and reduce consumption in cement rotary kiln. The technology of oxygen-enriched combustion can not only increase the calcination temperature of clinker, increase the output and quality of clinker, but also save fuel. Reducing emissions of harmful gases (mainly no _ x) and reducing air pollution. Although oxygen-enriched combustion has been used in cement rotary kilns as a new combustion technology a small amount of research has been done. However, the research on the combination of oxygen-enriched combustion technology and pulverized coal burner used in cement kiln has not been reported. An oxygen-enriched low NOx burner was designed to apply oxygen-enriched combustion technology to primary air. Numerical simulation of flow field under design condition was carried out with the aid of simulation software Fluent, and the velocity field, temperature field and concentration distribution of NOx in kiln were analyzed in detail. The numerical results accurately reflect the distribution of flow field in rotary kiln. Meanwhile, the effect of increasing oxygen concentration in primary air on temperature field and NOx concentration distribution in rotary kiln is studied. The results show that when the oxygen concentration is about 27%, the effect of saving energy and reducing NOx is obvious. Then, the numerical simulation mainly studies the effect of adjusting the operating parameters of the burner on the velocity field in the rotary kiln. Effect of temperature field and NOx concentration distribution. The three-channel burners used in a 1000T / D cement rotary kiln in China were reformed by using the simulation calculation results. The membrane oxygen processing equipment was also purchased and installed. After the operation of the equipment, the oxygen concentration in the primary air reached 26.8g, and the oxygen concentration reached 26.8g respectively before the oxygen-enriched kiln was passed through. The thermal test was carried out for the post-firing system. By comparing and analyzing the calibration data, it is concluded that the flame temperature is raised at least 120 鈩，

本文编号：1580382