本文關(guān)鍵詞： 預(yù)氧化 特征溫度 氣體產(chǎn)物 熱效應(yīng) 微觀特性 氧化動(dòng)力學(xué)　出處：《西安科技大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：煤炭是我國(guó)重要能源,為了節(jié)約資源,提高采出率,需要啟封已經(jīng)封閉的火區(qū)或者對(duì)采空區(qū)遺煤進(jìn)行復(fù)采,然而,這些煤層在開采時(shí)已經(jīng)與氧氣接觸發(fā)生了氧化,自燃特性可能發(fā)生了改變,稱這類煤的再次氧化為二次氧化,即煤在氧化燃燒前已經(jīng)經(jīng)過了一定程度的氧化,而后溫度又降回到常溫。文章選取了三個(gè)礦區(qū)的煤,分別預(yù)氧化至80℃、120℃、160℃和200℃,采用實(shí)驗(yàn)分析的方法,對(duì)比不同預(yù)氧化程度煤的二次氧化與一次氧化過程,研究煤二次氧化自燃特性,為火區(qū)啟封和遺煤復(fù)采煤自燃預(yù)測(cè)預(yù)報(bào)技術(shù)提供理論依據(jù)。主要內(nèi)容如下:(1)采用工業(yè)分析和紅外光譜法,對(duì)實(shí)驗(yàn)煤樣的工業(yè)參數(shù)和原始分子中主要官能團(tuán)進(jìn)行測(cè)試,發(fā)現(xiàn)預(yù)氧化至120℃的煤樣揮發(fā)分含量增加;不同煤樣的分子官能團(tuán)中,含量由多到少依次是含氧官能團(tuán)芳香烴脂肪烴;不同預(yù)氧化煤樣官能團(tuán)含量變化規(guī)律較復(fù)雜,羥基、羧酸類基團(tuán)、脂肪烴總含量在預(yù)氧化至120℃時(shí)達(dá)到極大值,醚鍵和取代苯變化規(guī)律性不強(qiáng)。(2)通過TG/DSC-FTIR實(shí)驗(yàn),對(duì)煤樣一次氧化和二次氧化過程的特征溫度、熱效應(yīng)和氣體產(chǎn)物變化規(guī)律進(jìn)行分析,結(jié)果表明,不同預(yù)氧化程度煤二次氧化特征溫度主要在受熱分解溫度之前區(qū)別較大。不同預(yù)氧化程度的煤特征溫度隨著預(yù)氧化程度的加深,先降低后增加,且一般是預(yù)氧化至120℃時(shí)煤樣的特征溫度最低;在熱效應(yīng)方面,煤在氧化燃燒過程中先吸熱后放熱,但是以放熱為主。煤樣氧化燃燒放熱量隨著預(yù)氧化程度的增加先增加后減少,但是變質(zhì)程度不同,放熱量最大時(shí)對(duì)應(yīng)的預(yù)氧化溫度不同,大南湖煤預(yù)氧化至160℃時(shí)放熱量最大,顧北煤和陽泉煤預(yù)氧化至120℃時(shí)放熱量最大;在氣體產(chǎn)物方面,煤在氧化燃燒過程中CO、CO2及H2O(g)隨溫度的增加先增加后降低。不同預(yù)氧化程度煤樣在燃點(diǎn)溫度前產(chǎn)生氣體隨溫度的變化較大,過了燃點(diǎn)溫度,不同預(yù)氧化溫度煤樣產(chǎn)生氣體的曲線基本重合。三種變質(zhì)程度煤樣氣體產(chǎn)生量隨預(yù)氧化程度的增加先增加后降低,其中,預(yù)氧化至120℃的煤樣產(chǎn)生CO氣體的量最多,顧北煤和陽泉煤亦為預(yù)氧化至120℃的樣品產(chǎn)生H2O(g)的量最多,大南湖煤預(yù)氧化至80℃和預(yù)氧化至120℃的煤樣產(chǎn)生的H2O(g)含量最多。(3)采用傅里葉原位紅外實(shí)驗(yàn),對(duì)煤樣二次氧化過程分子官能團(tuán)變化規(guī)律進(jìn)行研究,結(jié)果表明,不同預(yù)氧化程度煤在二次氧化過程中分子官能團(tuán)變化趨勢(shì)相同,但變化量不同。不同煤樣在氧化過程中分子官能團(tuán)變化有共性,煤分子中官能團(tuán)除個(gè)別例外的,其余所有煤樣在升溫氧化過程中游離-OH鍵、酚、醇、醚、酯C-O鍵、脂肪烴、芳環(huán)C=C結(jié)構(gòu)和芳烴-CH鍵含量隨溫度的升高而降低。煤樣取代苯和羰基C=O鍵隨著溫度的升高含量增加。同一變質(zhì)程度,不同預(yù)氧化溫度煤樣二次氧化過程分子中主要官能團(tuán)在氧化前后含量總變化量除個(gè)別不同外,其余煤樣都是預(yù)氧化至80℃-160℃的煤樣含量總變化量最大,且在這些煤樣中預(yù)氧化至120℃的煤樣是最大值的比率占一半以上。(4)應(yīng)用改進(jìn)的KAS法對(duì)煤樣在受熱分解前動(dòng)力學(xué)進(jìn)行分析,得出不同煤樣在水分蒸發(fā)及氣體脫附階段,活化能隨轉(zhuǎn)化率的增加而降低。三種變質(zhì)程度的煤樣活化能隨預(yù)氧化程度的變化規(guī)律一致,都是預(yù)氧化至120 ℃的煤樣活化能最小,原煤及預(yù)氧化至200℃的煤樣活化能較大。在吸氧增重階段,活化能隨轉(zhuǎn)化率的增加而增大,不同預(yù)氧化程度煤樣都是預(yù)氧化至120℃的煤樣活化能最小。
[Abstract]:Coal is an important energy in China, in order to save resources, improve the recovery rate, need to have closed or unsealed fire in goaf of coal mining, however, oxidation occurs a coal seam has been in contact with oxygen in the mining, spontaneous combustion characteristics may change again, said this kind of coal oxidation for two times oxidation, namely coal oxidation in pre combustion has been a degree of oxidation, and then the temperature dropped back to normal. The paper selects three coal mining area, were pre oxidized to 80 degrees Celsius, 120 degrees, 160 degrees and 200 degrees, by the experimental analysis, the ratio of two different oxidation degree of pre oxidation of coal with an oxidation process of coal oxidation and spontaneous combustion characteristics for two times, and the residual coal mining coal firearea unsealing and provide a theoretical basis for the prediction of spontaneous combustion prediction technology. The main contents are as follows: (1) the industrial analysis and infrared spectroscopy of the industrial parameters and experimental coal sample The main functional groups original molecular testing found that volatile coal pre oxidation to 120 DEG C content increased; functional groups in different coal samples, the content from more to less followed by functional groups containing oxygen aromatic aliphatic hydrocarbon; variation of pre oxidation of coal sample groups were more complex, hydroxyl, carboxylic acid groups. Fat total hydrocarbon content reached the maximum value in the pre oxidation to 120 DEG C, substituted benzene ether bond and the variation is not strong. (2) through the TG/DSC-FTIR experiment, the characteristics of temperature of coal oxidation and a two oxidation process, the thermal effect and the variation of gas products were analyzed, the results show that the different pre the oxidation degree of two coal oxidation characteristics of temperature mainly before the thermal decomposition temperature difference is large. The coal characteristic temperature of different pre oxidation degree with pre oxidation degree deepening, firstly decreased and then increased, and generally pre oxidation to 120 DEG C when coal sample. The lowest temperature in heat syndrome; effect on coal oxidation in the combustion process after the first endothermic exothermic, but to heat. Oxidation of coal combustion heat release with the increase of the degree of pre oxidation increased first and then decreased, but the degree of metamorphism, the heat release corresponds to the maximum pre oxidation temperature of different Dananhu coal pre oxidation the heat to 160 degrees C, Gu BEIMEI and Yangquan coal pre oxidation to 120 DEG C when the maximum heat release; in product gas, coal oxidation in the combustion process of CO, CO2 and H2O (g) with the increase of temperature increases first and then decreases. The different degree of pre oxidation of coal samples in producing gas with the ignition temperature the temperature change is bigger, the ignition temperature curve coincide different pre oxidation temperature of coal generating gas. Three kinds of metamorphic degree of coal sample gas production increased with increasing of the degree of pre oxidation decrease after the pre oxidation temperature of 120 coal samples from C The maximum amount of O gas, H2O BEIMEI Gu and Yangquan coal for pre oxidation temperature of 120 samples (g) was highest in Dananhu coal pre oxidation to 80 DEG C and pre oxidation temperature of 120 coal samples from H2O (g) was the most. (3) by Fourier infrared in situ experiment. Study on the coal two molecular oxidation process of functional group changes. The results showed that the two molecules in the oxidation process of functional groups in different trends of pre oxidation degree of coal, but the change is different. Different coal sample molecules in the oxidation process of coal molecular functional groups are common functional groups with few exceptions, all the rest coal free -OH key in heating and oxidation process of phenol, alcohol, ether, ester C-O, aliphatic hydrocarbons, aromatic C=C and aromatic -CH bond content decreases with the increase of temperature. Benzene and carbonyl C=O increased with the increase of temperature in key coal instead. The same degree of metamorphism, different pre The main functional groups of coal oxidation temperature of two oxidation process in a molecular weight content of total variation before and after oxidation in addition to individual differences, the remaining coal is coal content of pre oxidation to 80 DEG -160 DEG the total variation is the largest, and in the coal pre oxidation temperature of 120 coal samples is the ratio of the maximum value. More than half (4). Analysis of coal samples in thermal decomposition kinetics before using the improved KAS method, different coal desorption stage in the evaporation of water and gas, the activation energies decrease with the increase of the conversion decreased. Three coal activation energy consistent with changes of the degree of pre oxidation. Is the pre oxidation temperature of 120 coal samples of coal and the minimum activation energy, pre oxidation temperature of 200 coal samples. The activation energy is higher in oxygen gain stage, the activation energy will increase with increasing conversion rate, different pre oxidation degree of coal samples are pre oxidation temperature of 120 coal samples of the living It can be the smallest.

【學(xué)位授予單位】：西安科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TD752.2

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 鄧軍;趙婧昱;張[?妮;王彩萍;;不同變質(zhì)程度煤二次氧化自燃的微觀特性試驗(yàn)[J];煤炭學(xué)報(bào);2016年05期

2 鄧軍;艾紹武;馬礪;胡安鵬;任立峰;李貝;;阻化劑對(duì)采空區(qū)遺煤初次和二次氧化特性的影響[J];煤炭科學(xué)技術(shù);2015年01期

3 王萌;;煤樣二次氧化過程中自燃特性規(guī)律研究[J];中州煤炭;2014年01期

4 鄧軍;趙婧昱;張[?妮;吳慷;張丹丹;趙萌燁;;陜西侏羅紀(jì)煤二次氧化自燃特性試驗(yàn)研究[J];中國(guó)安全科學(xué)學(xué)報(bào);2014年01期

5 陸偉;李金亮;楊興兵;;采用交叉點(diǎn)溫度法對(duì)啟封煤易復(fù)燃問題的研究[J];煤礦安全;2013年12期

6 文虎;姜華;翟小偉;王凱;朱興攀;;煤二次氧化氣體特征實(shí)驗(yàn)研究[J];煤礦安全;2013年09期

7 吳憲;齊慶杰;徐長(zhǎng)富;周新華;;古山礦065-2煤層自燃特性與指標(biāo)氣體實(shí)驗(yàn)研究[J];礦業(yè)安全與環(huán)保;2013年05期

8 潘樂書;楊永剛;;基于量熱分析煤低溫氧化中活化能研究[J];煤炭工程;2013年06期

9 郄利敏;;淺孔抽放技術(shù)在煤與瓦斯突出工作面的應(yīng)用[J];煤礦現(xiàn)代化;2012年06期

10 仲曉星;王德明;尹曉丹;;基于程序升溫的煤自燃臨界溫度測(cè)試方法[J];煤炭學(xué)報(bào);2010年S1期

相關(guān)會(huì)議論文 前1條

1 劉朝文;陸偉;徐俊;;煤自燃過程控制步驟的分析[A];中國(guó)煤炭學(xué)會(huì)煤礦安全專業(yè)委員會(huì)2009年學(xué)術(shù)研討會(huì)論文集[C];2009年

相關(guān)博士學(xué)位論文 前2條

1 李子文;低階煤的微觀結(jié)構(gòu)特征及其對(duì)瓦斯吸附解吸的控制機(jī)理研究[D];中國(guó)礦業(yè)大學(xué);2015年

2 楊漪;基于氧化特性的煤自燃阻化劑機(jī)理及性能研究[D];西安科技大學(xué);2015年

，

本文編號(hào)：1510040