催化裂化煙氣輪機葉片表面催化劑沉積結(jié)垢的模擬實驗與數(shù)值研究
發(fā)布時間：2019-01-01 08:01
【摘要】：近年來,隨著催化裂化工藝條件的不斷變化,催化裂化能量回收系統(tǒng)中的煙氣輪機葉片結(jié)垢的日益加劇,弄清催化劑顆粒在煙氣輪機葉片上的結(jié)垢機理對后續(xù)煙氣輪機阻垢技術(shù)的開發(fā)有至關(guān)重要的作用。本文通過理論分析、數(shù)值計算和模擬試驗的方法對催化劑顆粒在煙氣輪機葉片上的結(jié)垢情況進行了研究。首先,本文將催化劑顆粒簡化為理想彈塑性球體,運用彈塑性力學(xué)和碰撞接觸理論的相關(guān)知識,建立了催化劑顆粒在壁面上的新沉積模型。第二,基于該自建模型,并運用CFD軟件Fluent并結(jié)合用戶自定義函數(shù)(User Defined Function,UDF),本文對某廠雙級煙氣輪機進行了建模和內(nèi)部氣固兩相流場的數(shù)值計算分析。本文設(shè)計了模擬結(jié)垢實驗,通過一系列手段,保證了模擬實驗中催化劑顆粒的受力狀態(tài)與實際情況一致,從而得出與實際煙氣輪機垢樣在外貌相似的樣品,這比之前的研究前進了一步�；谠搶嶒灥臄�(shù)據(jù),本文通過多因素分析法研究了鈉、鈣、鐵、硫四種元素對催化劑結(jié)垢的影響,彌補了數(shù)值計算不能考慮催化劑顆�；瘜W(xué)特性變化的不足。同時,通過模擬試驗,本文進一步定量地研究了溫度、顆粒粒徑等對結(jié)垢的影響,擬合出關(guān)系式,從而為數(shù)值計算模型提供了重要參數(shù)。本文所做工作可為進一步研究催化裂化煙氣輪機的阻垢技術(shù)提供理論依據(jù)和方法指導(dǎo)。研究結(jié)果表明:本文所建沉積模型可以較好的與煙機實際運行情況吻合。雙級煙機的第一級承擔(dān)主要的能量轉(zhuǎn)換功能,該雙級煙氣輪機的靜葉葉形參數(shù)設(shè)計不夠合理,應(yīng)該進行葉形的結(jié)構(gòu)優(yōu)化設(shè)計;催化劑顆粒在葉片上的沉積結(jié)垢呈現(xiàn)“U”型規(guī)律,在葉片前緣和后緣處顆粒沉積較多,在葉片中部相對較少;鈉、鈣、鐵、硫四種金屬元素對催化劑結(jié)垢的促進作用從大到小的順序為:鐵、硫、鈉、鈣;鈉元素和硫元素之間存在較為嚴(yán)重的交互作用,在實際操作過程中,應(yīng)盡量避免這兩種金屬元素同時存在;隨著溫度的增大,催化劑結(jié)垢的幾率增大,兩者呈負(fù)相關(guān)關(guān)系,本文擬合出了兩者之間的關(guān)系式;催化劑顆粒易結(jié)垢的粒徑范圍是:15μm以下及20~25μm之間。
[Abstract]:In recent years, with the continuous change of FCC process conditions, the fouling of flue gas turbine blades in the FCC energy recovery system is becoming more and more serious. It is very important to understand the scaling mechanism of catalyst particles on flue gas turbine blade for the following development of scale inhibition technology of flue gas turbine. In this paper, the scaling of catalyst particles on flue gas turbine blades is studied by theoretical analysis, numerical calculation and simulation test. Firstly, the catalyst particle is simplified as an ideal elastic-plastic sphere, and a new deposition model of catalyst particle on the wall is established by using the knowledge of elastic-plastic mechanics and collision contact theory. Secondly, based on the self-built model, using the CFD software Fluent and the user-defined function (User Defined Function,UDF), the two-stage flue gas turbine in a factory is modeled and the internal gas-solid two-phase flow field is numerically calculated and analyzed. In this paper, a simulated scaling experiment is designed. By means of a series of means, the stress state of the catalyst particle in the simulation experiment is consistent with the actual situation, and the sample with similar appearance to the actual flue gas turbine scale sample is obtained. This is a step forward from previous research. Based on the experimental data, the effects of sodium, calcium, iron and sulfur on the scale of the catalyst were studied by multi-factor analysis, which made up for the deficiency of numerical calculation which could not consider the change of the catalyst particle chemical characteristics. At the same time, the influence of temperature and particle size on scaling is studied quantitatively by simulation experiments, and the relationship is fitted, which provides important parameters for numerical model. The work in this paper can provide theoretical basis and method guidance for further research on scale inhibition technology of FCC flue gas turbine. The results show that the deposition model in this paper is in good agreement with the actual operation of the smoke machine. The first stage of the two-stage smoke turbine has the main function of energy conversion. The design of the static blade shape parameters of the two-stage flue gas turbine is not reasonable, so the structural optimization of the blade should be carried out. The deposition and scaling of catalyst particles on the leaf showed a "U" pattern, and there were more particles in the front and rear edge of the leaf, but less in the middle of the leaf. The effects of sodium, calcium, iron and sulfur on catalyst scaling are as follows: iron, sulfur, sodium, calcium; There is a serious interaction between sodium element and sulfur element. In the process of practical operation, the existence of these two metal elements should be avoided as far as possible. With the increase of temperature, the probability of catalyst scaling increases, and there is a negative correlation between them. In this paper, the relationship between them is fitted. The particle size range of catalyst particles is below 15 渭 m and 20 ~ 25 渭 m.
【學(xué)位授予單位】：中國石油大學(xué)(華東)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TE96
[Abstract]:In recent years, with the continuous change of FCC process conditions, the fouling of flue gas turbine blades in the FCC energy recovery system is becoming more and more serious. It is very important to understand the scaling mechanism of catalyst particles on flue gas turbine blade for the following development of scale inhibition technology of flue gas turbine. In this paper, the scaling of catalyst particles on flue gas turbine blades is studied by theoretical analysis, numerical calculation and simulation test. Firstly, the catalyst particle is simplified as an ideal elastic-plastic sphere, and a new deposition model of catalyst particle on the wall is established by using the knowledge of elastic-plastic mechanics and collision contact theory. Secondly, based on the self-built model, using the CFD software Fluent and the user-defined function (User Defined Function,UDF), the two-stage flue gas turbine in a factory is modeled and the internal gas-solid two-phase flow field is numerically calculated and analyzed. In this paper, a simulated scaling experiment is designed. By means of a series of means, the stress state of the catalyst particle in the simulation experiment is consistent with the actual situation, and the sample with similar appearance to the actual flue gas turbine scale sample is obtained. This is a step forward from previous research. Based on the experimental data, the effects of sodium, calcium, iron and sulfur on the scale of the catalyst were studied by multi-factor analysis, which made up for the deficiency of numerical calculation which could not consider the change of the catalyst particle chemical characteristics. At the same time, the influence of temperature and particle size on scaling is studied quantitatively by simulation experiments, and the relationship is fitted, which provides important parameters for numerical model. The work in this paper can provide theoretical basis and method guidance for further research on scale inhibition technology of FCC flue gas turbine. The results show that the deposition model in this paper is in good agreement with the actual operation of the smoke machine. The first stage of the two-stage smoke turbine has the main function of energy conversion. The design of the static blade shape parameters of the two-stage flue gas turbine is not reasonable, so the structural optimization of the blade should be carried out. The deposition and scaling of catalyst particles on the leaf showed a "U" pattern, and there were more particles in the front and rear edge of the leaf, but less in the middle of the leaf. The effects of sodium, calcium, iron and sulfur on catalyst scaling are as follows: iron, sulfur, sodium, calcium; There is a serious interaction between sodium element and sulfur element. In the process of practical operation, the existence of these two metal elements should be avoided as far as possible. With the increase of temperature, the probability of catalyst scaling increases, and there is a negative correlation between them. In this paper, the relationship between them is fitted. The particle size range of catalyst particles is below 15 渭 m and 20 ~ 25 渭 m.
【學(xué)位授予單位】：中國石油大學(xué)(華東)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TE96
【參考文獻】
相關(guān)期刊論文 前10條
1 許友好;;我國催化裂化工藝技術(shù)進展[J];中國科學(xué):化學(xué);2014年01期
2 胡仁波;白銳;趙晉，
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