【作者】 李科；

【导师】 安连锁；

【作者基本信息】 华北电力大学（北京） ， 热能工程， 2008， 硕士

【摘要】 炉膛温度是电站锅炉重要的运行参数。声学法具有实时监测,操作简单,非接触等优点,是传统测温方法很好的替代产品。本文基于国内外研究现状,对声学法测温系统的设计进行了研究。基于matlab平台,对普通互相关算法和高阶累积量算法进行仿真比较,指出在锅炉炉膛背景噪声条件下,使用高阶累积量法具有更好的准确性和抗干扰性,更适合用来测量声波飞渡时间。比较电动声源的各种信号,发现伪随机序列信号和扫频信号互相关性符合测温信号要求,并且伪随机序列信号具有更好的抗噪性能,测量稳定性和准确性。在实验室条件下,对比不同喷口口径喷流和电动扫频声源的指向性,得到结论:在模拟声学测温系统布置的各测点上气动声源比电动扫频声波各测点声压级波动大。设计开发了采用模拟输入卡I/O,采用模拟输出卡的两种发声控制方式的电声源八通道声学测温系统,分析比较两套系统在硬件和软件系统设计上的优劣。实验室试验验证系统可靠性。并提出采用模拟输出卡的气动声源测温系统的设计思路。更多还原

【Abstract】 Temperature field is a important reference for the operation of a power plant. Measuring method on acoustic has the property of on-line continuous measurement, non-intrusive measurement, which is a good replacement of traditional measuring methods. In this article, based on the former research, the design of the measuring system on acoustic method has been studied.By simulation and experiment, the algorithm to measure sound wave time-of-delay, selection of the sound source and measuring signal were simulated and experimented. The conclusion is that the TDE method is more reliable and acurrate for the measuring system than the orginal Cross-correlation method.The pseudo-random binary sequence(PRBS) and the chirp single are both suitable for the measuring system,in which PRBS signal has better property of antinoise.Jet noise was studied,the sound-pressure-level field of different jet noise and sound from electric speaker are detected, the variance is larger from jet noise than from electric speaker chirp signal.2 types of temperature measuring system were designed, whose sound output stretage are based on the I/O of the aquisition card and analogy output card. They are also experimented in lab condition, which were proved the feasibility. A design idea was metioned for the measuring system based on the jet noise.更多还原