本文關鍵詞：煤自燃指標氣體生成特性及內(nèi)在規(guī)律性研究　出處：《太原理工大學》2017年碩士論文　論文類型：學位論文

  更多相關文章： 煤自燃 指標氣體 內(nèi)在規(guī)律 預測預報 灰色關聯(lián)

【摘要】：長久以來,煤自燃不僅制約著礦井安全生產(chǎn)工作,而且浪費寶貴的煤炭資源,煤自燃預測預報對及時治理煤自燃有指導意義。煤自熱過程中產(chǎn)生的指標氣體在煤自燃預測預報工作中具有重要作用,在此基礎上本文通過對指標氣體生成規(guī)律及其內(nèi)在關系的研究,探索煤自燃機理,目的是給預測和治理煤自燃提供理論依據(jù),增加指標氣體的應用價值。本文選取自燃傾向性不同的錫盟褐煤、神東長焰煤和義馬氣煤三種不同變質(zhì)程度的煤作為研究對象。采用程序升溫氧化和恒溫氧化的實驗方法,研究在不同煤化程度、溫度、粒徑、質(zhì)量和反應體積條件下煤自燃過程中指標氣體H_2、CO、CO_2和C_2H_4的釋放規(guī)律。同時以灰色關聯(lián)理論和多元線性回歸模型,探討指標氣體之間的內(nèi)在關聯(lián)性。得出以下結論:(1)在煤自燃過程中,H_2與C_2H_4的釋放規(guī)律相似,隨著溫度的升高,它們的生成量呈指數(shù)型增長,適合作為指標氣體。(2)在煤自燃過程中,煤在30℃條件下就開始吸收O_2生成CO和CO_2等氣體。隨著溫度的升高CO與CO_2的生成量均呈現(xiàn)指數(shù)型增長。在恒溫氧化過程中,較低溫度條件下CO生成量隨反應時間的增長符合“S”型的邏輯斯蒂增長模型,而在較高溫度下呈現(xiàn)出對數(shù)型增長趨勢。對于不同煤種,兩種不同增長模型發(fā)生轉變的臨界溫度為:褐煤100℃、長焰煤120℃、氣煤120℃。在自燃過程中,CO_2的生成量隨時間的變化呈對數(shù)型增長,CO_2的生成規(guī)律不隨溫度變化。(3)在恒溫氧化過程中,CO_2和CO生成速率的比值在不同溫度條件下是穩(wěn)定的數(shù)值。這一比值受煤種特性和供氧條件的影響。當氧氣不足時的比值大于氧氣充足時的比值。說明當氧氣減小時,CO對氧氣的變化更為敏感,即CO的生成過程中氧氣具有明顯的促進作用。CO_2對氧氣的不敏感說明了CO_2的生成不只來源于煤氧結合,部分來自于煤內(nèi)部含氧官能團(如羧基)等中間絡合物的分解。(4)通過對各種指標氣體生成規(guī)律的研究,發(fā)現(xiàn)H_2、CH_4、C_2H_4、C_2H_6和CO_2的生成之間有緊密的協(xié)同性。運用灰色關聯(lián)分析方法得到指標氣體之間的關聯(lián)度,將生成規(guī)律與關聯(lián)度相結合對指標氣體進行分類:(1)H_2、C_2H_4、CO_2;(2)CO、CO_2;(3)CH_4、C_2H_4、C_2H_6。三種指標氣體體系的分類中重復的指標氣體表明了部分指標氣體的生成途徑不唯一,表明煤自燃過程中存在著多種反應序列。(5)運用多元線性回歸模型,對關聯(lián)緊密的指標氣體進行擬合,得到它們之間的數(shù)學關系。通過分析計算發(fā)現(xiàn):C_2H_4的生成對CO_2的生成呈促進作用;H_2的生成和O_2的消耗在不同條件下對CO_2的生成分為促進作用與抑制作用兩種。
[Abstract]:For a long time, coal spontaneous combustion has not only restricted the safety of mine production, but also wasted valuable coal resources. The prediction and prediction of coal spontaneous combustion is of guiding significance for the timely control of coal spontaneous combustion. The index gas produced in the process of coal spontaneous heating plays an important role in the prediction and prediction of coal spontaneous combustion. On this basis, through the study of the law of index gas generation and its internal relations, this paper explores the mechanism of coal spontaneous combustion, in order to provide a theoretical basis for the prediction and treatment of coal spontaneous combustion. In this paper, Ximeng lignite with different spontaneous combustion tendency is selected. Three kinds of coal with different metamorphism degree were used as the research object. The experimental methods of programmed temperature oxidation and constant temperature oxidation were used to study the coalification degree, temperature and particle size. The release law of index gases H _ 2CO _ 2 and C _ 2H _ 4 in the process of coal spontaneous combustion under the condition of mass and reaction volume. At the same time, the grey correlation theory and multivariate linear regression model are used. The following conclusion is drawn: (1) in the process of spontaneous combustion of coal, the release regularity of H _ (2) and C _ 2H _ (4) is similar to that of C _ 2H _ (4), with the increase of temperature. It is suitable to be used as an index gas in the process of coal spontaneous combustion. At 30 鈩，

本文編號：1438674