【作者】 陈春燕；

【导师】 倪明江； 黄群星；

【作者基本信息】 浙江大学 ， 热能工程， 2011， 硕士

【摘要】 焚烧法因为其物料适应性广、减量化、无害化等明显优点已成为发达国家处理废弃物的主要途径,在我国主要城市也已建立了焚烧处理厂,开始这方面的研究。但同时,研究指出垃圾焚烧也已成为剧毒物质二噁英类化合物产生的主要来源。目前普遍认为二噁英类化合物的生成与窑内温度场分布有着密切联系,同时焚烧炉内的温度场分布对于焚烧系统的稳定运行、减少窑内结渣等也有着重要意义。而目前典型的废弃物焚烧系统对温度监控仍采用热电偶式测温装置,无法反应整个焚烧系统内实际温度的分布情况。因此本文基于对弥散介质的辐射传递特性的计算方法的研究,尝试将利用火焰辐射对焚烧炉内截面温度场反演重建的技术应用于回转窑焚烧炉。首先基于Mie散射理论,对球形固体颗粒的辐射特性进行了研究；并计算了回转窑内碳粒及飞灰粒子云的辐射特性参数。对于气体介质的辐射特性参数计算,比较了谱带模型法和逐线计算法的差异,认为谱带模型法的计算精度适用于工程应用,可用于焚烧炉内混合气体的辐射参数计算。随后使用Fluent对废弃物回转窑焚烧状况作了数值模拟,得出了燃烧空间内的温度场分布及气体介质浓度场分布。在此基础上对红外热像仪的发射率设置进行了计算。最终以两段式回转窑焚烧炉为研究对象,基于逆向Monte Carlo方法,提出了利用电荷耦合器件摄像机所获取的辐射信息进行炉膛断面二维弥散介质温度场快速重建的模型。应用最小二乘QR(LSQR)矩阵分解算法结合维恩定律即可重建出截面温度场。并进行了现场试验研究,试验结果证实了重建方法的可行性和实用性。更多还原

【Abstract】 Incinerating the wastes has become the main way in developed countries because of its wide adaptability and other obvious advantages. Some incineration plants also have been established in our major cities. However, it’s reported that waste incineration has become the main source of the formation of dioxin-like c ompounds.It’s widely accepted that the formation of dioxins is closely linked to the kiln temperature distribution, while the temperature distribution of the incinerator is important for the stable operation of burning system and reduction of slagging. However traditional power station boilers and waste incinerators are still using thermocouples for temperature monitoring, which can not reflect the actual temperature field of the incinerator. So we tried to reconstruct the temperature distribution of a kiln incinerator.The radiative property of the solid particles was discussed and calculated based on Mie scattering theories. The line-by-line model and band model have been used to calculate the absorption coefficient of molecular gases, and we found that the band model is good enough for engineering. Then we used fluent to simulate the combusting in a kiln incinerator, obtained both the temperature distribution and gas concentration distribution. Then the radiation parameters of the medium were calculated for the emissivity setting of a Infrared Thermograpic Camera.At last we attempted to reconstruct the 2D temperature distribution of a rotary kiln hazardous waste incinerator. A reconstruction model of temperature distribution based on the back-Monte Carlo method was proposed, using the flame images captured by charge-coupled device cameras. A matrix-decomposition-based least squares algorithm was introduced to reconstruct the emission intensity distribution in the kiln sections. The proposed method was found to be capable and effective through practical approaches.更多还原