【作者】 柳岩；

【导师】 彭世尼；

【作者基本信息】 重庆大学 ， 供热、供燃气、通风及空调工程， 2011， 硕士

【摘要】 工业窑炉应用燃气辐射管加热装置可降低窑炉的基础建设和运行成本,提高生产效率,延长窑炉寿命。燃气辐射管的燃烧气氛及燃烧产物不与被加热工件直接接触,大大提高产品的质量,目前在金属热处理及工业干燥领域中广泛应用。本课题研制了适用于中低温场合的燃气辐射管,由专门设计的引射式燃气燃烧器和石英管组成,自然排烟,辐射管内为负压,安全环保节能。石英管表面黑度高,不需考虑管壁温度的均匀性以及燃烧产物的腐蚀性对辐射管寿命的影响。本论文对燃气辐射管的热工性能进行实验研究和数值模拟。重点研究了燃气流量、一次空气系数、加入插入物这三个因素对辐射管壁面温度、功率、效率及污染物含量的影响规律,另外二次空气预热温度、辐射管的管长与管径等因素对性能的影响也做了简单的研究。论文还对燃气辐射管热工性能进行了正交数字试验研究,通过方差分析得到了燃气流量、一次空气系数和二次空气调节装置高度这三个因素以及各因素之间的交互作用对考核指标的影响程度。在原先的燃气辐射管的基础上,为进一步提高其效率,论文的最后部分对燃烧器装置进行了优化,通过对几种方案的数值模拟结果的比较,选择最优方案,从而达到强化燃气空气的混合,提高燃气辐射管效率的目的。本论文采用的数值模拟方法可清晰的展现辐射管内燃烧状态下的温度场、流场及组分分布,丰富了对辐射管燃烧技术的认识和理解,该研究成果将对燃气辐射管的工业化应用提供理论依据与经验。更多还原

【Abstract】 The application of gas radiant tube to industrial furnace is economic and appropriate. It can not only reduce the capital construction and running costs, increase production efficiency and lengthen the life of the furnace, but combustion atmosphere and product doesn’t contact with heated objects directly. So it will not have an effect on the quality of product. On the contrary, the quality of heated product will be greatly improved, thus it’s used widely in the area of metallic heat treatment particularly.This subject develops gas radiant tube that’s applicable for medium-temperature industrial drying kiln.Injective gas burner is designed according to the requirements of design parameters. The way of air supply is suction type,natural draft is used and it shows negative pressure in the pipe. Therefore,it is able to save energy during the safe manufacturing. Choosing vycor as the material of radiant tube, no matter whether the uniformity of wall temperature and the corrosivity of combustion products have effects on the life of tube or not.Firstly, conduct a basic experimental study on the thermal performance of gas radiant tube. It focuses on the impact of the three factors(gas consumption, the change of primary air coefficient, adding insert) on the wall temperature of radiant tube and the content of pollutants. Secondly, use burning mathematical model on the basis of the study to do a numerical simulation on the combustion process in gas radiant tube under different conditions. It analyses the thermal performance of gas radiant tube through combustion field of gas and air in the tube(temperature field, concentration field, velocity field of combustion and mass fraction field of combustion product.)Numerical simulation goes from two parts: in line with analysis of variance on the result of quadrate digital test about the thermal performance of gas radiant tube ,the first part finds the significant degree of influence, the three factors—gas consumption, primary air coefficient and controlling device’s height of secondary air, have on assessment indicators, as well as the impact of the interaction among all factors on thermal performance. By experimental study of single-factor figures on the thermal performance of gas radiant tube,the second part finds the influence rules of primary air coefficient, gas consumption, air preheating temperature, radiant tube’s length and caliber’s change on the thermal performance of gas radiant tube(mainly refers to power and efficiency).In order to improve the operational efficiency of gas radiant tube, the last part of this paper optimizes the burner devices. Mainly starting from improving flow patterns and mixing way of gas and air, optimization methods adjusts length and angle on the basis of the original secondary air controlling device. Optimal solution is selected through the comparison in the numerical simulation results of several programs. The purposes of strengthening the mixture of gas and air flow and improving the full extent of gas burning have been achieved.This article conducts a comprehensive study on the thermal performance of radiant tube by numerical simulation and experiment. The most important thing is that it can clearly show temperature field, flow field and component distribution under the burning condition in the radiant tube and enrich our awareness and understanding of the technology about radiant tube combustion. Therefore, using the way of the combination of experimental and numerical simulation can deepen our understanding of the basic phenomenon and process of combustion in gas radiant tube. The research findings will provide theoretical basis and experience on industrialized applications of gas radiant tube.更多还原