煤粉粒度分布的在线连续测量对保证锅炉的安全、可靠、经济和低污染运行具有十分重要的现实意义。现有的测量手段主要依靠人工采样和离线分析，无法用于锅炉的在线调整与燃烧优化，而国内外所尝试的各种在线测量方法由于精度、价格、可靠性、耐用性等原因而无法实际应用。本项目旨在研究基于声发射信号的煤粉粒度分布在线测量技术，通过检测颗粒与探头碰撞产生的弹性应力波，结合静电相关测速技术，对煤粉粒度进行在线连续测量。本项目通过理论建模、仿真分析、实验测试等途径深入揭示颗粒碰撞声发射信号的产生、传播与接收机理，提出声发射信号特征参数提取与粒径反演算法，完成在线测量系统的设计与实现，并在实验室与燃煤电厂进行样机的实验测试。所研制的测量系统结构简单、成本低、可适应恶劣工业环境、对维护要求低、且具有良好的耐用性。拟开展的理论与实验研究将为新型粒度分布在线测量仪表提供理论基础和技术支撑，具有重要的科学研究和应用价值。

On-line continuous measurement of the size distribution of pulverized coal in power plant is essential for the safe, reliable, economical and low-emission operation of the boiler. Currently, sizing of pulverized coal is achieved through manual sample collection and subsequent laboratory analysis. The off-line results cannot be used for on-line adjustment of the pulverizer and combustion optimization of the boiler. A variety of on-line techniques has been attempted worldwide, but none of them has been successfully deployed in the industrial field due to inadequacies in accuracy, price, reliability and durability. The objective of this project is to develop an on-line particle sizing technique through acoustic emission (AE) detection. Information about particle size can be extracted from the elastic stress wave generated by the particle collision with a metallic probe and the particle velocity obtained from a correlation-based electrostatic velocimetry. Theoretical modeling, simulation analysis and experimental studies will be conducted to uncover the underlying mechanism of AE signal generation, propagation and reception. Algorithms for feature extraction and size inversion will be proposed. Three prototype instruments will be developed and tested in both laboratory and coal-fired power plant. The instruments to be developed in this project are simple in structure, low in cost, suitable for hostile industrial environment, low in maintenance requirement and durable for long-term operation. The theoretical and experimental studies to be carried out, which are of great value for both scientific research and industrial application, will provide theoretical foundation and technical support for this novel on-line particle sizing instrument.