【作者】 郑娇丽；

【导师】 徐志明；

【作者基本信息】 东北电力大学 ， 流体机械及工程， 2011， 硕士

【摘要】 为寻求判别燃煤锅炉结渣特性的统一标准,本文选择适合我国标准的灰的软化温度、碱酸比、硅比、硅铝比、无因次炉膛平均温度和无因次炉膛切圆直径六个指标作为输入,以锅炉实际结渣程度作为输出,建立判别燃煤锅炉结渣倾向的非线性迭代PLS数字模式识别模型。把炉膛结渣程度分为轻微、中等、严重三种情况,分别记作第1类(记为1)、第2类(记为2)、第3类(记为3),并规定把预测值小于1.5的归为第1类,预测值大于或等于1.5小于2.5的归为第2类,大于或等于2.5的归为第3类。结果表明,本模型具有很好的预测效果和适用范围,其回判准确率和预报准确率均为100%。为了更精确地预测换热设备的结垢情况,本文选择影响松花江水结垢的11个主要水质参数:铁离子、氯离子、细菌总数、pH值、溶解氧、浊度、电导率、细菌总数、碱度、硬度和时间等作为输入参数,任一组不同时刻的20组数据作为模型的训练(前15组)和检测样本(后5组),建立了板式换热器的污垢热阻预测模型,此模型预测效果良好。然后去掉模型的部分水质参数,并根据其预测结果分析水质参数对污垢的影响。本文用60个已知煤灰变形温度的样本,以十个煤灰成份作为输入变量,利用PLS回归模型对煤灰变形温度DT进行预测。然后依次减少PLS回归模型输入变量的个数来预测灰熔点,并比较其预测结果。结果表明,采用10个煤灰成分作为输入变量时的预测结果最精确。更多还原

【Abstract】 To seek for the uniform standards to judge characteristics of coal boiler slagging, this thesis chooses the six parameters including ash softening temperature, alkaline acid ratio, silicon ratio, silicon aluminum ratio, average temperature of non-dimensional hearth furnace and non-dimensional cut circle diameter as inputs. Boiler actual slagging degree is chosen as output, and establishes nonlinear iterative partial least squares regression (PLS) digital pattern recognition model discriminating the coal boiler slagging tendency. The degree of hearth slagging can be divided into three kinds, namely mild, moderate, and severe. These three kinds can be written as 1st class (note for 1), notes 2nd class (notes for 2) and the 3rd class (notes for 3), respectively; and the predictive value which is less than 1.5 is divided into the first category which, is equal to or greater than 1.5 less than 2.5 and is divided into the second category, which is equal to or greater than 2.5. It is gathered for the third kinds. Results show that the accuracy of forecasting and the accuracy of the back sentence to all is 100%.In order to accurately predict the fouling of heat exchange equipment, the time and 10 main water quality parameters have effect on the scaling of Songhuajiang river are iron, chloride ion, bacteria, pH value, dissolved oxygen, turbidity, conductivity, bacteria, alkalinity, hardness, etc. They were used as input variables. This thesis chooses 20 groups of data at different times, with the former 15 groups as a model of training and the latter 5 groups as test sample, and establishes a prediction model of plate heat exchanger of fouling resistances. This model has achieved good prediction results. Then the paper establishes anti-removed part prediction model of water quality parameters, and analyses the influence of water quality parameters dirt according to its prediction results. Adopting ten components of coal ash as input variables, the model for ash fusion which was trained by 60 samples was set up by use of partial least-square regression method. Then the PLS regression model is used to forecast ash deformation temperature (DT) of the coal with orderly decreased input variables. The predicted results with different numbers of ash component as the input variables were compared. Results show that the predicting results using ten components of coal ash as input variables are most accurate.更多还原