燃煤火电机组煤粉浓度超声检测机理与方法研究

项目名称： 燃煤火电机组煤粉浓度超声检测机理与方法研究

项目编号： No.51476028

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 能源与动力工程

项目作者： 王培红

作者单位： 东南大学

项目金额： 80万元

中文摘要： 火电机组燃煤锅炉一次风管道中空气与煤粉的混合流动是具有稀疏固相特征的复杂气固两相流动，实现固相（煤粉）浓度检测是锅炉燃烧优化面临的技术难题之一。本项目开展燃煤锅炉煤粉浓度的超声检测机理与方法研究。首先，构建实验平台用于机理和实验研究；其次，采用机理分析与实验测试相结合的方法，设计与煤粉浓度、煤粉颗粒粒径、物性参数及超声频率相关的多因素多水平正交实验，研究风粉两相流中超声波的衰减机理和声速传播特性，建立适用于燃煤锅炉风粉两相流的超声衰减和声速传播特性模型（简称超声响应机理模型）及其样本矩阵；第三，开展证据理论研究，提出一种证据反演推理算法，用于实现由超声响应机理模型（或样本矩阵）反演测算获得煤粉浓度，该方法具有较高的算法适用性、计算复杂度小等特点，可用于在线实时反演，确保提出的煤粉浓度超声检测方法可用于实时检测。本项目研究成果对实现锅炉燃烧优化、提高燃烧效率、降低燃烧污染物排放具有重要意义。

中文关键词： 测控技术；气固两相流；煤粉浓度；反演算法；超声

英文摘要： In coal-fired power plant, the mixture of air and coal powder in the primary air pipe is a typical gas-solid two-phase flow with spare solid phase. How to measure the concentration of the solid pahse (coal powder) is difficut in the thermal process. Therefore, this project aim to investigate the principle and method on measuring concentration of coal powder based on the principle of ultrasonic acoustic. Firstly, an experiment station is established, with which, the principle of measuring concentration of coal powder by using ultrasonic can be investigated by conducting series of experiments. Secondly, by combination of orthogonal experiments and ultrasonic theory analysis, the propagation characteristics of ultrasonic waves including ultrasonic attenuation and velocity are investigated under diferent conditions where a wide various of concentrations of coal powder, distribution of coal powder, physic parameters of coal and air,and ultrasonic frequency are considered.The mechanism model is then established just for the air-coal two-phase. Thirdly, an inverse inference algorithm is proposed based on theory of belief fnction, which is used to obtain an inverse model. By combination of established mechanism model and inverse model, the real (or optimal) concetration of coal powder can be inversely inferred for the sample to be measured. Note that, the proposed inverse inference algorithm based on theory of belief function can be used online due to its low computational complexity and robustness. Hence, a ultrasonic method is finally proposed to measure the concentration of coal powder online. The researches in this project can make significant contributions on realizing the optimization of boiler combustion, enhancing the efficiency of boiler combustion, and reducing the amount of pollutant discharge.

英文关键词： measurement and control technology;gas-solid two-phase flow;concentration of pulverized coal;inverse algorithm;ultrasonic