提高不均匀流场气体流量测量准确性的试验研究

论文总字数：24370字

摘 要

大型电站一、二次风量控制直接关系着锅炉的稳定燃烧、运行安全、防止结焦、降低污染物排放等，是火电厂安全、经济、环保运行的主要工作内容之一。同时，电站锅炉的排烟量测量也极其重要。而电厂中的管道、风烟道复杂，直管段较短、弯管段较多，造成流场较为紊乱，流动截面速度分布不均，单点或少数几个点测量的差压值不能很好的反映截面总的风烟流量。因此，研究气体流量测量装置对不均匀流场的适应性并对其进行改进优化很有必要。

本论文前面介绍了课题的研究背景及意义，进而讨论到气体流量测量装置国内外研究现状及发展趋势，同时也提到本课题主要研究内容。

首先对现在常见的气体流量计进行了分类，然后对目前火电厂常用的机翼型流量测量装置、文丘里流量测量装置、均速管流量测量装置、矩阵式流量测量装置进行了简要介绍，并针对测量信号的稳定性、对不均匀流场的适应性（或上下游直管段要求）、防堵灰特性等方面进行了对比，分析其各自的优缺点。

试验阶段首先对矩阵式（无节流孔）流量测量装置进行了试验，发现此装置稳定性、准确性较高，但是其布点对截面的代表性不高，差压信号转换不准确，特别是对不均匀流场的适应性不是很好；对其优化改进后，添加了节流孔，进一步试验后，发现准确性提高，但对不均匀流场的适应性仍然不是很强；所以设计了一种新的气体流量测量装置——新型截面式流量测量装置，对其进行试验，数据表明其稳定性、准确性都较高，同时对不均匀流场的适应性也较强。

关键词：气体流量测量装置，不均匀流场，矩阵式流量测量装置，新型截面式流量测量装置

Abstract

The primary and secondary air volume control of large-scale power station is directly related to the stable combustion of the boiler, the safe operation of the boiler, the prevention of coking and reduce pollutant emissions. It is one of the main contents of the safety, economic and environmental protection of thermal power plants. At the same time, power plant boiler smoke exhaust volume measurement is also extremely important. The power plant in the pipeline, the wind flue complex, straight pipe section is shorter, more curved pipe section, resulting in a more turbulent flow field, the flow velocity distribution uneven, single or a few points measured the value of the differential pressure can not be very good reflects the flow of smoke of the total cross-section. Therefore, it is necessary to study the adaptability of the gas flow measurement device to the uneven flow field and to optimize it.

This paper introduces the background and significance of the research, and then discusses the current situation and development trend of gas flow measurement device at home and abroad, and also points out the main research contents of this subject.

First of all, the common gas flowmeter is classified, and then the current thermal power plant commonly used airfoil flow measuring device, venturi flow measurement device, the average speed tube flow measurement device, matrix flow measurement device is briefly introduced, and the advantages and disadvantages of the measurement signal stability, the adaptability to the uneven flow field (or the requirements of the upstream and downstream straight pipe), the anti - blocking characteristics and so on are analyzed.

In the experiment, it was found that the stability and accuracy of the matrix flow measuring device were high. However, the distribution of the cross-section of the representative is not high and the differential pressure signal conversion was not accurate. In particular, the adaptability to the uneven flow field is not very good; after its optimization and improvement, the orifice is added. After further testing, the accuracy is improved, but the adaptability to the uneven flow field is still not very strong; therefore, a new gas flow measuring device is designed, which is a new cross-section flow measurement device. The data show that the stability and accuracy are high, and the adaptability to the uneven flow field is also strong.

Key words: Gas flow measurement device, uneven flow field, matrix flow measurement device, new cross-section flow measurement device

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1引言 1

1.2课题研究背景及意义 1

1.3气体流量测量技术研究现状及趋势 1

1.4本课题主要研究内容 2

第二章 常见气体流量测量技术简介 4

2.1常见气体流量测量原理概述 4

2.2典型差压式气体流量测量装置 4

2.2.1均速管 4

2.2.2机翼型流量测量装置 5

2.2.3文丘里流量测量装置 6

2.2.4矩阵式流量测量装置 6

2.3本章小结 7

第三章 试验平台、试验件及试验流场 8

3.1试验平台 8

3.2试验件 10

3.2.1矩阵式流量测量装置 10

3.2.2新型截面式流量测量装置 10

3.3试验流场 12

3.4本章小结 14

第四章 矩阵式流量测量装置对不均匀流场的适应性探究 15

4.1矩阵布点的流场代表性 15

4.2矩阵均压理论的试验探究 17

4.3矩阵式流量测量装置改进思路 19

4.4新型截面式流量测量装置 20

4.5本章小结 22

第五章 结论 24

致 谢 25

参考文献 26

1. 绪论

1.1引言

测量流体的流量，是民用以及工业参数测量中较复杂的一种测量，它在国民经济、国防建设科学研究中的地位非常重要。随着我国工农业的发展，对流体流量的测量提出了越来越多的要求，由于各种流体，如天然气、石油、水等，都是重要的能源，特别是近几年来，由于环境污染以及节能、智能管理系统的出现，无论是从质量上还是从数量上，都更重视以过程状态量为中心的现场数据，气体流量是其中比较基础和关键的一环。只有做到准确的计量，才能做到“节能有数、耗能有据”，因此，需要更好、更多的流量计量仪表^【1】。

剩余内容已隐藏，请支付后下载全文，论文总字数：24370字