本文選題：預(yù)熱催化氧化器　切入點(diǎn)：甲烷　出處：《山東理工大學(xué)》2013年碩士論文　論文類型：學(xué)位論文

【摘要】：中國(guó)是煤炭能源大國(guó),每年通過煤礦乏風(fēng)排入大氣的甲烷既造成了清潔能源的巨大浪費(fèi),又污染了大氣環(huán)境。由于乏風(fēng)瓦斯中甲烷含量低、濃度波動(dòng)范圍廣且排風(fēng)量大等特點(diǎn),風(fēng)排瓦斯的治理利用一直是個(gè)大難題。預(yù)熱催化氧化反應(yīng)器是山東理工大學(xué)自主研發(fā)的一種處理乏風(fēng)瓦斯的催化氧化裝置,它不僅具有結(jié)構(gòu)緊湊、占地面積小、機(jī)械強(qiáng)度高等優(yōu)點(diǎn),而且利用反應(yīng)后的廢氣預(yù)熱新鮮進(jìn)氣進(jìn)行能量回收,減少了能耗,提高了熱利用率和催化氧化床進(jìn)氣溫度、省去加熱裝置,具有節(jié)能和環(huán)保的雙重意義。 本文研究了擴(kuò)張段的導(dǎo)流分配方案,對(duì)裝置運(yùn)行參數(shù)、氧化床結(jié)構(gòu)參數(shù)和陶瓷參數(shù)的變化對(duì)流場(chǎng)的影響規(guī)律進(jìn)行了試驗(yàn)研究和數(shù)值模擬計(jì)算,主要研究?jī)?nèi)容包括： (1)建造處理量為1000m3/h的預(yù)熱催化氧化反應(yīng)器試驗(yàn)臺(tái)及數(shù)值計(jì)算模型,研究冷態(tài)流場(chǎng)下反應(yīng)室入口截面處氣流速度分布的均勻性。模擬結(jié)果顯示出與實(shí)驗(yàn)結(jié)果一致的速度分布規(guī)律,都表現(xiàn)為中間速度高,周圍速度偏低的一種態(tài)勢(shì),且氧化床頂部及底部很大一部分處于低速度區(qū),速度分布極不均勻。 (2)對(duì)預(yù)熱催化氧化反應(yīng)器反應(yīng)室入口的導(dǎo)流分配系統(tǒng)進(jìn)行數(shù)值模擬計(jì)算,確定了擴(kuò)張段的最佳導(dǎo)流分配方案。未加導(dǎo)流板時(shí)的原模型反應(yīng)室氧化床入口截面的速度分布不均勻性系數(shù)為0.8左右；布置水平導(dǎo)流板之后縱向速度分布有一定改善,不均勻性系數(shù)降低到0.5左右；增加垂直導(dǎo)流板后速度分布的均勻性明顯提高,不均勻性系數(shù)降低到0.2左右。 (3)分析冷態(tài)流場(chǎng)下氧化床參數(shù)的變化對(duì)速度分布均勻性的影響,催化床層前端布置均溫均流床層可以顯著改善催化床入口截面的速度分布均勻性；均溫均流床層與催化床層間距為10mm左右時(shí),對(duì)速度分布均勻性改善最佳；氧化床長(zhǎng)度和孔隙率的變化對(duì)其影響不是很大；在裝置結(jié)構(gòu)尺寸一定的條件下,氧化床橫截面邊長(zhǎng)在550mm和600mm之間時(shí)速度均勻性較好。 (4)運(yùn)行參數(shù)、陶瓷參數(shù)及催化劑參數(shù)對(duì)流場(chǎng)的影響：氣流速度增大將會(huì)縮短甲烷分子在壁面的駐留時(shí)間,導(dǎo)致溫升緩慢,降低甲烷轉(zhuǎn)化率；適當(dāng)提高入口溫度和甲烷濃度有利于反應(yīng)初期吸附基元反應(yīng)的發(fā)生,對(duì)壁面催化反應(yīng)具有促進(jìn)作用；在其它條件不變的情況下,增大陶瓷床的比表面積可以增加甲烷分子與活性微粒觸碰的頻率,加快某些關(guān)鍵基元反應(yīng)的速率；適當(dāng)增加催化劑涂覆量可以增加活性位數(shù)目,有利于催化反應(yīng)的進(jìn)行。 (5)導(dǎo)流板對(duì)熱態(tài)流場(chǎng)的影響：在反應(yīng)室擴(kuò)張段安裝導(dǎo)流板后,氧化床入口截面的速度分布不均勻系數(shù)從0.5降低到0.18左右；氧化床中部橫截面上的溫度場(chǎng)不均勻系數(shù)幾乎為零,溫度梯度非常小,陶瓷氧化床運(yùn)行的安全性大大提高；同一橫截面的甲烷濃度不均勻系數(shù)降低,床體底部甲烷濃度波動(dòng)比較大的現(xiàn)象明顯改善,整體氣流完全反應(yīng)的時(shí)間和距離縮短,這樣可以根據(jù)風(fēng)量處理要求適當(dāng)縮減床體長(zhǎng)度,節(jié)約裝置成本。
[Abstract]:Chinese coal energy power, each year through the coal mine ventilation air methane into the atmosphere has caused a huge waste of clean energy, and pollution of the atmospheric environment. The methane content of VAM in low concentration fluctuation range and characteristics of large volume discharge, exhaust gas treatment and preheating has been a big problem. Catalytic oxidation catalytic oxidation reactor is a device for processing developed by Shandong University of Technology, VAM, it not only has the advantages of compact structure, small occupied area, high mechanical strength and so on, and the reaction of the waste gas preheating intake of fresh energy recovery, reduce energy consumption, improve the rate of catalytic oxidation bed and inlet temperature heat utilization. Save the heating device, which has dual significance of energy saving and environmental protection.
In this paper, the diversion diversion plan of expansion section is studied. The influence of operation parameters of the plant, the structural parameters of the oxidation bed and the change of ceramic parameters on the flow field is studied by numerical simulation and experiment.
(1) the construction of the processing capacity of preheating 1000m3/h catalytic oxidation reactor test and numerical calculation model of cold state flow field under the reaction chamber entrance section of air velocity distribution. The simulation results show good agreement with experimental results showed the velocity distribution in high speed, a situation around the speed the low, and the oxidation bed top and bottom of a large part in the low speed region, the velocity distribution is very uneven.
(2) the distribution system of diversion entrance reaction preheating catalytic oxidation reactor chamber by numerical simulation, the optimum flow distribution scheme expansion section. The original model of the reaction chamber entrance section of the oxidation bed without deflectors of the velocity distribution uniformity coefficient was about 0.8; after the layout of horizontal guide plate longitudinal velocity distribution there is some improvement, the non-uniformity coefficient is reduced to about 0.5; increase the speed distribution of the vertical guide plate after uniformity was obviously improved, the non-uniformity coefficient is reduced to about 0.2.
(3)鍒嗘瀽鍐鋒，

本文編號(hào)：1557603