本文選題：分級(jí)燃燒 + 數(shù)值模擬��； 參考：《上海發(fā)電設(shè)備成套設(shè)計(jì)研究院》2017年碩士論文

【摘要】：我國(guó)是世界燃煤大國(guó),而其中電廠發(fā)電占了約60%的煤炭使用比例。由燃煤帶來(lái)的環(huán)境問題日益突出,在其排放的各種污染物中,氮氧化物(NOx)對(duì)環(huán)境的影響最為明顯,因此控制NOx排放量為電廠清潔排放的首要指標(biāo)。目前廣泛采用的是在原一次風(fēng)、二次風(fēng)基礎(chǔ)上增設(shè)燃燼風(fēng)來(lái)降低NOx排放。燃燼風(fēng)的配風(fēng)率和相對(duì)高度對(duì)于爐膛出口煙溫有著重要的影響,而爐膛出口煙溫的變化關(guān)系到鍋爐整體性能的計(jì)算和運(yùn)行的經(jīng)濟(jì)性,是鍋爐能否實(shí)現(xiàn)設(shè)計(jì)性能的一個(gè)重要參數(shù),對(duì)鍋爐安全經(jīng)濟(jì)運(yùn)行具有直接的影響。過去采用的爐膛出口溫度計(jì)算方法只考慮了一次風(fēng)的變化而忽略了二次風(fēng)的配風(fēng)比,由于采用空氣分級(jí)燃燒以后二次風(fēng)需抽調(diào)一部分比例的風(fēng)量來(lái)在爐膛主燃區(qū)上方形成補(bǔ)燃區(qū)域,因此改變二次風(fēng)的配風(fēng)比以及結(jié)構(gòu)以后對(duì)爐膛出口的溫度有著明顯的影響。隨著CFD技術(shù)的發(fā)展,對(duì)于爐膛出口溫度的計(jì)算方法修正可以不再局限于實(shí)驗(yàn)法,可節(jié)約大量的時(shí)間和人力成本。本文以實(shí)際改造案例為基礎(chǔ),對(duì)超臨界鍋爐燃燼風(fēng)配風(fēng)率和相對(duì)高度的變化進(jìn)行數(shù)值模擬,研究這些因素對(duì)爐膛出口煙溫的影響,初步分析并總結(jié)燃燼風(fēng)配風(fēng)率和相對(duì)高度對(duì)爐膛出口煙溫的變化規(guī)律,探討相應(yīng)的計(jì)算方法。希望能為鍋爐的設(shè)計(jì)或改造提供有益的參考。研究借助FLUENT對(duì)珠海電廠一期600MW超臨界鍋爐進(jìn)行模擬,以鍋爐BMCR工況數(shù)據(jù)為基礎(chǔ),選取不同燃燼風(fēng)率和相對(duì)高度位置對(duì)整個(gè)爐膛進(jìn)行燃燒模擬,并與實(shí)際工程改造數(shù)據(jù)相比對(duì),期望找出燃燼風(fēng)率和相對(duì)高度變化對(duì)爐膛出口煙溫影響的回歸分析表達(dá)式,即燃燒條件影響系數(shù)的計(jì)算方法。燃燼風(fēng)相對(duì)高度對(duì)爐膛出口溫度的影響主要體現(xiàn)在分離燃燼風(fēng)層和主燃區(qū)上層燃燒器之間的間隔,本文提出了表征該影響因素的新的當(dāng)量比,與燃燼風(fēng)率共同構(gòu)成了新的燃燒條件影響系數(shù)算法。該算法表明:燃燼風(fēng)相對(duì)高度對(duì)爐膛出口溫度變化有一個(gè)正負(fù)斜率區(qū)間,當(dāng)燃燼風(fēng)相對(duì)高度低于一定值時(shí),爐膛出口溫度與燃燼風(fēng)率為負(fù)斜率線性關(guān)系,當(dāng)燃燼風(fēng)相對(duì)高度高于一定值時(shí),爐膛出口溫度與燃燼風(fēng)率為正斜率線性關(guān)系。改進(jìn)后的燃燒條件影響系數(shù)總體為原燃燒條件影響系數(shù)的0.9倍左右,即加設(shè)燃燼風(fēng)后爐膛燃燒火焰中心會(huì)有所抬高,并且爐膛出口溫度會(huì)隨燃燼風(fēng)率和相對(duì)高度的變化而變化。實(shí)際工程初步驗(yàn)證,結(jié)果表明該計(jì)算方法具有一定可信度。
[Abstract]:China is a big coal-burning country in the world, and about 60% of the coal is used by power plants. The environmental problems caused by coal combustion are becoming more and more prominent. Among the pollutants emitted, no _ x (no _ x) has the most obvious impact on the environment. Therefore, controlling the NOx emission is the primary index of clean emission in power plants. At present, it is widely used to reduce NOx emissions by adding cinder wind on the basis of primary and secondary air. The air distribution rate and relative height of the burning cinder have an important influence on the flue gas temperature at the outlet of the furnace, and the change of the flue gas temperature at the outlet of the furnace is related to the calculation of the overall performance of the boiler and the economy of its operation, and is an important parameter of whether the boiler can realize the design performance. It has direct influence on the safe and economical operation of boiler. In the past, the furnace outlet temperature calculation method only considered the change of primary air and neglected the ratio of secondary air to air distribution. Since it is necessary to adjust a part of the air volume of the secondary air after the air staged combustion to form a supplementary combustion area above the main combustion zone of the furnace, the change of the air distribution ratio of the secondary air and the structure of the secondary air have an obvious influence on the temperature of the furnace outlet. With the development of CFD technology, the calculation method of furnace outlet temperature can not be limited to the experimental method, and can save a lot of time and labor costs. In this paper, based on the actual reconstruction cases, the variation of the air distribution rate and the relative height of the burning cinder of supercritical boiler is simulated, and the influence of these factors on the flue gas temperature at the outlet of the furnace is studied. The variation law of air distribution ratio and relative height of burning cinder on flue gas temperature at furnace outlet is analyzed and summarized preliminarily, and the corresponding calculation method is discussed. It is hoped that it can provide useful reference for boiler design or renovation. In this paper, the 600MW supercritical boiler of Zhuhai Power Plant is simulated by FLUENT. Based on the boiler BMCR working condition data, the combustion simulation of the whole furnace is carried out at different burning cinder rates and relative height, and compared with the actual engineering reconstruction data. It is expected to find out the regression expression of the influence of the burning cinder rate and the relative height on the flue gas temperature at the outlet of the furnace, that is, the calculation method of the influence coefficient of the combustion condition. The influence of the relative height of cinder air on the outlet temperature of furnace is mainly reflected in the interval between the upper burner of separating the cinder layer and the upper layer of the main combustion zone. In this paper, a new equivalent ratio characterizing the influence factor is proposed. Together with the cinder rate, a new algorithm for calculating the influence coefficient of combustion conditions is proposed. The algorithm shows that there is a positive and negative slope range between the relative height of burning cinder and the temperature of furnace outlet. When the relative height of burning cinder is lower than a certain value, the linear relationship between furnace outlet temperature and cinder rate is linear. When the relative height of burning embers is higher than a certain value, the linear relationship between furnace outlet temperature and cinder rate is linear. The influence coefficient of the improved combustion condition is about 0.9 times of that of the original combustion condition, that is, the combustion flame center of the furnace will be raised with the addition of cinder air, and the furnace outlet temperature will change with the change of the cinder rate and the relative height. The experimental results show that the method is reliable.
【學(xué)位授予單位】：上海發(fā)電設(shè)備成套設(shè)計(jì)研究院
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TM621.2

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 楊飛;;不同配風(fēng)對(duì)四角切圓Ⅱ型爐參數(shù)的影響[J];科技創(chuàng)新導(dǎo)報(bào);2016年05期

2 邵思蜜;;電廠低NOx燃燒技術(shù)專利分析[J];情報(bào)探索;2015年04期

3 李中朋;李澤宇;馬強(qiáng);;PDF輸運(yùn)方程模型模擬燃燒實(shí)例簡(jiǎn)析[J];科技資訊;2015年09期

4 楊姣;孫保民;;600MW機(jī)組鍋爐空氣分級(jí)低NO_x燃燒數(shù)值模擬[J];熱力發(fā)電;2014年10期

5 李剛;;清潔煤技術(shù)的研究進(jìn)展及發(fā)展前景[J];化工管理;2014年24期

6 王金良;;化石燃料電廠CO_2俘獲方案研究[J];安全、健康和環(huán)境;2013年12期

7 徐芳;李寶;;爐膛出口煙溫計(jì)算方法的研究[J];黑龍江電力;2013年02期

8 陳振龍;姚偉;王桂芳;;空氣分級(jí)燃燒鍋爐的運(yùn)行安全經(jīng)濟(jì)性研究[J];熱力發(fā)電;2011年12期

9 閆甲鵬;;超臨界鍋爐與600KW超超臨界鍋爐結(jié)構(gòu)定量分析[J];黑龍江科技信息;2011年01期

10 陳鴻偉;孫超;李德育;危日光;;電站鍋爐豎井內(nèi)空氣動(dòng)力學(xué)特性研究[J];華東電力;2010年11期

相關(guān)博士學(xué)位論文 前1條

1 馬斌;大型超臨界、超超臨界鍋爐低NOx燃燒系統(tǒng)研究[D];浙江大學(xué);2007年

相關(guān)碩士學(xué)位論文 前10條

1 尹莉;臭氧協(xié)同強(qiáng)電離放電法模擬煙氣脫硫脫硝的研究[D];江蘇大學(xué);2016年

2 孫文浩;點(diǎn)火槍火焰穩(wěn)定性的數(shù)值模擬及試驗(yàn)研究[D];華中科技大學(xué);2013年

3 代中元;基于FLUENT的某型號(hào)板翅式換熱器的性能數(shù)值模擬及其結(jié)構(gòu)優(yōu)化[D];武漢理工大學(xué);2013年

4 徐立椺;300MW級(jí)鍋爐再熱汽溫低及再熱器增容改造的研究[D];華北電力大學(xué);2012年

5 張申;動(dòng)力定位推力系統(tǒng)水動(dòng)力干擾研究[D];上海交通大學(xué);2011年

6 武進(jìn)猛;1000MW超超臨界鍋爐爐內(nèi)燃燒過程數(shù)值模擬[D];華北電力大學(xué);2011年

7 王次成;四角切圓鍋爐爐膛燃燒器高寬比對(duì)爐內(nèi)動(dòng)力場(chǎng)及溫度場(chǎng)影響的研究[D];上海交通大學(xué);2010年

8 張維俠;600MW亞臨界鍋爐低NOx燃燒改造設(shè)計(jì)與數(shù)值模擬[D];上海交通大學(xué);2008年

9 陸杰;鍋爐整體空氣分級(jí)燃燒NOx排放及控制的關(guān)鍵問題的試驗(yàn)研究[D];上海交通大學(xué);2008年

10 王素娟;垂直分級(jí)水平濃淡煤粉燃燒器降低NO_X排放的數(shù)值模擬[D];哈爾濱工業(yè)大學(xué);2007年

，

本文編號(hào)：1804545