本文選題：煤粉 + 氣固兩相流��； 參考：《華北電力大學(xué)(北京)》2017年碩士論文

【摘要】：燃煤電廠一次風(fēng)管道內(nèi)煤粉顆粒粒度和質(zhì)量流量的在線測(cè)量可以為實(shí)時(shí)調(diào)節(jié)制粉系統(tǒng)工作參數(shù)提供依據(jù),有助于優(yōu)化制粉系統(tǒng)工作性能、提高煤粉燃燒效率并降低污染物排放。靜電傳感器具有測(cè)量特性穩(wěn)定、安裝方便、靈敏度高、維護(hù)需求低和本質(zhì)安全等優(yōu)點(diǎn),已被應(yīng)用于工業(yè)氣固兩相流速度、濃度等重要?jiǎng)討B(tài)參數(shù)的測(cè)量。本論文首先從理論和實(shí)驗(yàn)兩方面探索了利用靜電傳感器測(cè)量煤粉顆粒粒度的可行性,利用有限元仿真軟件COMSOL分析了單個(gè)顆粒的粒度對(duì)靜電信號(hào)強(qiáng)度和頻率的影響。然后根據(jù)靜電法測(cè)量原理提出了基于渡越時(shí)間的單顆粒粒度測(cè)量方法,以及基于顆粒速度變化的多顆粒粒度估測(cè)方法。實(shí)驗(yàn)選用石英砂和活性炭?jī)煞N不同性質(zhì)的材料在74 mm管徑的氣固兩相流裝置上進(jìn)行,測(cè)量裝置使用2mm和10 mm兩種不同軸向?qū)挾鹊撵o電電極。最后通過(guò)實(shí)驗(yàn)研究了含水率對(duì)靜電法測(cè)量顆粒質(zhì)量流量的影響,并改進(jìn)了質(zhì)量流量測(cè)量中相關(guān)系數(shù)的標(biāo)定方法。有限元仿真結(jié)果表明當(dāng)顆粒帶電密度相等時(shí)可以通過(guò)測(cè)量靜電信號(hào)強(qiáng)度分辨顆粒粒度,當(dāng)顆粒沿環(huán)形靜電傳感器軸向運(yùn)動(dòng)時(shí)其所處的徑向位置對(duì)靜電信號(hào)頻率造成的影響大于顆粒粒度的影響。實(shí)驗(yàn)結(jié)果表明顆粒粒度會(huì)影響靜電信號(hào)的強(qiáng)度和主頻,當(dāng)氣力輸送管道內(nèi)風(fēng)速一定時(shí)顆粒速度隨其粒度增大而減小,因此可以通過(guò)顆粒速度變化推測(cè)顆粒粒度。同等條件下顆粒含水率不同,靜電傳感器對(duì)顆粒質(zhì)量流量測(cè)量結(jié)果不同,針對(duì)不同含水率條件標(biāo)定質(zhì)量流量測(cè)量系數(shù)可以有效提高測(cè)量的準(zhǔn)確性。
[Abstract]:On-line measurement of pulverized coal particle size and mass flow in primary air pipe of coal-fired power plant can provide basis for real-time adjusting the working parameters of pulverizing system, help to optimize the working performance of pulverizing system, improve the efficiency of pulverized coal combustion and reduce pollutant emission. Electrostatic sensor has the advantages of stable measurement characteristics, convenient installation, high sensitivity, low maintenance requirement and essential safety. It has been applied to the measurement of important dynamic parameters such as velocity and concentration of gas-solid two-phase flow in industry. In this paper, the feasibility of using electrostatic sensor to measure particle size of pulverized coal is explored in theory and experiment, and the influence of particle size of single particle on the intensity and frequency of electrostatic signal is analyzed by using finite element simulation software COMSOL. Then, according to the principle of electrostatic measurement, a single particle size measurement method based on transit time and a multi-particle particle size estimation method based on the variation of particle velocity are proposed. Two kinds of materials with different properties, quartz sand and activated carbon, were used in the gas-solid two-phase flow device with the diameter of 74 mm tube. The measuring apparatus used two kinds of electrostatic electrodes with different axial width of 2mm and 10mm. Finally, the effect of water content on particle mass flow is studied by experiments, and the calibration method of correlation coefficient in mass flow measurement is improved. The finite element simulation results show that the particle size can be resolved by measuring the electrostatic signal strength when the charged density of particles is equal. When the particle moves along the axial direction of the ring electrostatic sensor, the influence of the radial position on the frequency of the electrostatic signal is greater than that of the particle size. The experimental results show that the particle size will affect the intensity and frequency of electrostatic signal, and the particle velocity decreases with the increase of particle size when the wind velocity in the pneumatic conveying pipeline is fixed, so the particle size can be estimated by the change of particle velocity. Under the same conditions, the measurement results of particle mass flow rate by electrostatic sensor are different, and the accuracy of measurement can be effectively improved by calibrating the mass flow measurement coefficient according to different water content conditions.
【學(xué)位授予單位】：華北電力大學(xué)(北京)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TP212

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 朱利;鄭會(huì)志;張冬雪;祝華杰;耿書(shū)平;;蒙皮材料靜電起電理論分析及實(shí)驗(yàn)驗(yàn)證[J];高電壓技術(shù);2014年09期

2 張振中;白宏剛;;顆粒粒徑的光散射法測(cè)量研究[J];山西科技;2011年01期

3 李芬芬;張本山;;淀粉顆粒粒徑不同測(cè)定方法的比較[J];食品與發(fā)酵工業(yè);2010年04期

4 孫猛;劉石;雷兢;李志宏;;電廠送粉系統(tǒng)煤粉濃度和速度的在線測(cè)量技術(shù)研究[J];熱能動(dòng)力工程;2009年02期

5 馬平;周曉寧;田沛;;過(guò)程層析成像技術(shù)的發(fā)展及應(yīng)用[J];化工自動(dòng)化及儀表;2009年01期

6 李文凱;吳玉新;黃志民;樊融;呂俊復(fù);;激光粒度分析和篩分法測(cè)粒徑分布的比較[J];中國(guó)粉體技術(shù);2007年05期

7 趙春芳;不同方法測(cè)試粒度分布的比較研究[J];中國(guó)粉體技術(shù);2004年02期

8 蔡小舒,潘詠志,吳偉亮,歐陽(yáng)新,蘇明旭,俞基安,胡杰;電廠煤粉粒徑、濃度和速度的在線測(cè)量技術(shù)研究[J];動(dòng)力工程;1999年06期

9 顏華,王師;電容層析成像技術(shù)及應(yīng)用[J];工業(yè)儀表與自動(dòng)化裝置;1999年03期

10 袁竹林,盧作基;用傳熱法測(cè)量燃煤鍋爐氣力輸送中煤流量的研究[J];燃燒科學(xué)與技術(shù);1999年01期

相關(guān)博士學(xué)位論文 前2條

1 張文彪;靜電法稀相氣固兩相流測(cè)量機(jī)理研究[D];天津大學(xué);2014年

2 許傳龍;氣固兩相流顆粒荷電及流動(dòng)參數(shù)檢測(cè)方法研究[D];東南大學(xué);2006年

相關(guān)碩士學(xué)位論文 前1條

1 薛明華;超聲法測(cè)量顆粒兩相流粒徑及濃度的理論及實(shí)驗(yàn)研究[D];上海理工大學(xué);2008年

，

本文編號(hào)：1812849