本文關(guān)鍵詞： 火焰淬熄 電學(xué)特性 控制變量 數(shù)值模擬　出處：《哈爾濱工業(yè)大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著微型機(jī)電系統(tǒng)的快速發(fā)展,人們對(duì)于結(jié)構(gòu)尺寸更小,功率密度更大的微型能源系統(tǒng)的需求愈加迫切。微尺度燃燒動(dòng)力系統(tǒng)由于能量密度高的特點(diǎn)而受到了廣泛的關(guān)注。然而微尺度燃燒與常規(guī)燃燒相比會(huì)產(chǎn)生很多新的問題。微尺度燃燒不能維持穩(wěn)定,會(huì)發(fā)生淬熄即熄火。由于火焰本身是一種弱電離的等離子體,碳?xì)淙剂系幕鹧嬷泻性S多諸如CHO+、H3O+、e、OH-等直接與化學(xué)反應(yīng)相關(guān)的帶電的粒子,淬熄發(fā)生時(shí)火焰速度降低,最終停止向壁面?zhèn)鞑?會(huì)引起上述帶電粒子數(shù)量與分布的變化。因此,對(duì)于火焰淬熄的電學(xué)特性研究十分必要。本課題從理論分析、實(shí)驗(yàn)研究?jī)煞矫鎸?duì)層流穩(wěn)態(tài)火焰淬熄電學(xué)特性進(jìn)行了研究,利用數(shù)值模擬方法對(duì)層流火焰淬熄時(shí)的燃燒特性進(jìn)行了分析,對(duì)層流火焰淬熄時(shí)參數(shù)的變化規(guī)律進(jìn)行了探討。本課題研究結(jié)果如下:設(shè)計(jì)并搭建了層流火焰淬熄的電學(xué)特性實(shí)驗(yàn)臺(tái)。本課題采用控制變量法進(jìn)行實(shí)驗(yàn)。理論方面從分子動(dòng)理論角度得到了粒子近碰撞的頻率值,并且從等離子角度得到了直流小電場(chǎng)條件下火焰的電導(dǎo)率的數(shù)量級(jí)為10-8。采用控制變量法,只改變?nèi)紵髋c淬熄平面之間的電壓值。電壓值取20V、40V、60V、80V,發(fā)現(xiàn)電壓加載方向影響電流大小,燃燒器上為負(fù)電壓時(shí)電流較大。電流值隨著電壓值的增大而增大。在一定范圍內(nèi),同一高度處火焰的電阻值保持不變,不隨著電壓大小的變化而變化。淬熄平面的材質(zhì)對(duì)于火焰淬熄的電學(xué)特性影響較小。淬熄時(shí),隨著距離的減小,火焰向上的傳播受到了阻礙,火焰的高溫區(qū)向著燃燒器左右兩側(cè)移動(dòng),并且反應(yīng)區(qū)域內(nèi)最高溫度降低。CO2的含量先增加后減小,CO的含量先增加后減小。距離50mm條件下,隨著空氣量的增加,火焰淬熄時(shí)的溫度最大值逐漸升高。火焰的高溫區(qū)域隨著空氣量的增加逐漸向著中間區(qū)域集中;軸向速度逐漸升高;CO的質(zhì)量分?jǐn)?shù)逐漸減小,并且CO質(zhì)量分?jǐn)?shù)的最高值的位置呈下降趨勢(shì);CO2的質(zhì)量分?jǐn)?shù)最大值逐漸下降,火焰的CO2的質(zhì)量分?jǐn)?shù)較大的區(qū)域隨著空氣量的增加逐漸向著中間區(qū)域集中。
[Abstract]:With the rapid development of MEMS, the size of structure is smaller. The demand of micro-energy system with higher power density is becoming more and more urgent. The micro-scale combustion power system has attracted wide attention because of its high energy density. However, micro-scale combustion will produce many new ones compared with conventional combustion. Microscale combustion cannot be maintained stable. Since the flame itself is a weakly dissociated plasma, the flame of hydrocarbon fuel contains many such as CHO H3O OE. OH- and other charged particles directly related to chemical reactions will cause changes in the number and distribution of charged particles when quenching occurs and the flame velocity decreases and eventually stops propagating to the wall. It is necessary to study the electrical properties of flame quenching. In this paper, the electrical properties of laminar steady flame quenching are studied from two aspects: theoretical analysis and experimental study. The combustion characteristics of laminar flame quenching were analyzed by numerical simulation. The variation of the parameters of laminar flame quenching is discussed. The results are as follows:. The electrical characteristics of laminar flame quenching were designed and built. The control variable method was used in the experiment. In theory, the frequency of particle near collision was obtained from the viewpoint of molecular kinetic theory. The order of magnitude of the flame conductivity under the condition of a small DC electric field is obtained from the plasma angle. By using the control variable method, only the voltage between the burner and the quenching plane is changed, and the voltage value is 20V. It is found that the voltage loading direction affects the current size, and the current is larger when the burner is negative voltage. The current value increases with the increase of the voltage value, and within a certain range. The resistance of flame at the same height remains constant and does not change with the change of voltage. The material of quenching plane has little effect on the electrical properties of flame quenching. The upward propagation of the flame is hindered, the high temperature region of the flame moves to the right and left sides of the burner, and the maximum temperature in the reaction region decreases. The content of CO2 increases first and then decreases. The content of CO increased first and then decreased. At the distance of 50mm, the content of CO increased with the increase of air volume. When the flame quenched, the maximum temperature gradually increased. The high temperature region of the flame gradually concentrated towards the middle region with the increase of the air volume. Axial velocity increased gradually; The mass fraction of CO gradually decreased, and the position of the highest value of the mass fraction of CO decreased. The maximum mass fraction of CO2 decreases gradually, and the region with higher mass fraction of CO2 in flame is gradually concentrated in the middle region with the increase of air volume.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2016
【分類號(hào)】：TK16
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本文編號(hào)：1453536