烟道截面面积校准装置模型研究及不确定度评定

Study on the Stack Cross Section Area Calibration Facility and Its Uncertainty Evaluation

为了保证基于速度面积法烟道流量测量的准确性,需要准确测量出烟道截面面积。研发了一套烟道截面面积在线校准装置,能准确测量烟道内部几何尺寸,进而计算截面面积。讨论了基于随机抽样一致性截面面积拟合算法以及基于最小二乘法截面面积算法拟合计算的拟合特性,对比并优化后的拟合模型测量平均值的最大偏差为0.02%,装置测量重复性为0.013%。同时对装置的测量不确定进行评定,校准装置相对扩展不确定度为0.17%(k=2)。

In order to ensure the accuracy of stack flowrate measurement based on velocity area method,it is necessary to accurately measure the stack cross section area.A stack cross section area calibration facility is developed,which can accurately measure the internal geometry of stack,and then calculat cross section area.At the same time,the cross section area fitting characteristics of random sampling method and least square method are discussed.After comparison and optimization,the maximum error of the average value of the fitted model is 0.02%,and the facility repeatability is 0.013%.Meanwhile the measurement uncertainty of the facility is evaluated,and the relative expended uncertainty is 0.17%(k=2).