本文選題：四分倉(cāng)回轉(zhuǎn)式空預(yù)器 + 熱力計(jì)算模型��； 參考：《華北電力大學(xué)》2017年碩士論文

【摘要】：未來(lái)很長(zhǎng)一段時(shí)間內(nèi),火力發(fā)電仍將占據(jù)我國(guó)發(fā)電行業(yè)的主要地位。最近幾年來(lái),隨著環(huán)保問(wèn)題越來(lái)越嚴(yán)重,循環(huán)流化床鍋爐的工程應(yīng)用規(guī)模加大,并且大容量的煤粉鍋爐也得到了快速的發(fā)展,由于四分倉(cāng)空預(yù)器漏風(fēng)率低等特點(diǎn),所以四分倉(cāng)空預(yù)器得到了快速的發(fā)展和應(yīng)用。同時(shí),隨著鍋爐加裝脫硝裝置以后,空預(yù)器產(chǎn)生低溫腐蝕和積灰堵塞的問(wèn)題會(huì)更加嚴(yán)重,因此研究四分倉(cāng)空預(yù)器傳熱特性以及分析加裝脫硝裝置后對(duì)空預(yù)器的影響,對(duì)四分倉(cāng)空預(yù)器的安全運(yùn)行以及低溫腐蝕問(wèn)題有著重要的指導(dǎo)意義。本文針對(duì)四分倉(cāng)回轉(zhuǎn)式空預(yù)器的運(yùn)行方式和傳熱特點(diǎn),采用了分段集總參數(shù)法,建立了四分倉(cāng)回轉(zhuǎn)式空預(yù)器熱力計(jì)算模型。通過(guò)Fortran語(yǔ)言將數(shù)學(xué)模型轉(zhuǎn)化成仿真系統(tǒng)的一個(gè)通用算法,運(yùn)用工程模塊化建模的方法,借助一體化仿真支撐系統(tǒng)軟件平臺(tái),以某300MW循環(huán)流化床鍋爐的四分倉(cāng)空氣預(yù)熱器為實(shí)例,對(duì)其進(jìn)行熱力計(jì)算,得到了該空預(yù)器的煙氣、空氣以及蓄熱元件的溫度分布。并在此熱力計(jì)算的基礎(chǔ)上,本文又對(duì)煙氣中硫酸和硫酸氫銨的結(jié)露點(diǎn)進(jìn)行了計(jì)算,研究了加裝脫硝裝置后空預(yù)器內(nèi)硫酸和硫酸氫銨結(jié)露帶的分布。結(jié)果表明:BMCR工況下煙氣出口溫度的計(jì)算值與設(shè)計(jì)值的相對(duì)偏差為0.3%,一次風(fēng)出口溫度計(jì)算值與設(shè)計(jì)值的相對(duì)偏差為0.2%,而左、右二次風(fēng)出口溫度的計(jì)算值與設(shè)計(jì)值完全吻合;并且進(jìn)一步計(jì)算了三個(gè)不同工況下的出口煙溫和出口風(fēng)溫,計(jì)算值與設(shè)計(jì)值的最大相對(duì)偏差為0.5%,從而驗(yàn)證模型的正確性與可靠性。轉(zhuǎn)子旋轉(zhuǎn)一周,隨著轉(zhuǎn)子角度的增加,不同工況下的煙氣出口溫度是逐漸增加的;金屬壁溫是先升高,然后慢慢降低到原來(lái)的溫度。不管爐內(nèi)有無(wú)脫硫,隨著機(jī)組負(fù)荷的降低,硫酸氫銨和硫酸結(jié)露帶的高度是增加的;加裝脫硝裝置后,當(dāng)進(jìn)口煙溫降低10℃,硫酸氫氨和硫酸結(jié)露帶的高度是增加的,但是硫酸氫銨結(jié)露對(duì)空預(yù)器的影響要比硫酸結(jié)露大的多;隨著爐內(nèi)脫硫效率的提高,各工況下空預(yù)器中硫酸氫銨結(jié)露帶的高度也是降低的。
[Abstract]:Thermal power generation will still occupy the main position of power generation industry in China for a long time in the future.In recent years, with the environmental protection problem becoming more and more serious, the engineering application scale of circulating fluidized bed boiler has been enlarged, and the large capacity pulverized coal boiler has been developed rapidly, because of the low air leakage rate of the air preheater in the fourth compartment, etc.Therefore, the four-compartment air preheater has been rapidly developed and applied.At the same time, with the installation of denitrification unit in the boiler, the problems of low temperature corrosion and ash accumulation will become more serious, so the heat transfer characteristics of the air preheater and the effect of adding the denitrification device on the air preheater are studied.It has important guiding significance for safe operation of air preheater and low temperature corrosion.In view of the operation mode and heat transfer characteristics of the four-compartment rotary air preheater, a thermodynamic calculation model of the four-compartment rotary air preheater is established by using the piecewise lumped parameter method.The mathematical model is transformed into a general algorithm of the simulation system by Fortran language. By using the method of engineering modular modeling and the software platform of integrated simulation support system, the air preheater of a 300MW circulating fluidized bed boiler is taken as an example.The temperature distribution of flue gas, air and heat storage element of the air preheater is obtained by thermal calculation.On the basis of the thermodynamic calculation, the condensation point of sulphuric acid and ammonium hydrogen sulfate in flue gas is calculated, and the distribution of condensation zone of sulfuric acid and ammonium hydrogen sulfate in air preheater after adding denitrification unit is studied.The results show that the relative deviation between the calculated value of flue gas outlet temperature and the design value is 0.3, the relative deviation between the calculated value of primary air outlet temperature and the design value is 0.2 and the calculated value of left and right secondary air outlet temperature is in good agreement with the design value.The maximum relative deviation between the calculated value and the design value is 0.5, which verifies the correctness and reliability of the model.With the increase of rotor angle the outlet temperature of flue gas increases gradually and the metal wall temperature increases first and then decreases to the original temperature.Regardless of whether there is desulfurization in the furnace or not, the height of ammonium hydrogen sulfate and sulphuric acid condensation zone increases with the reduction of unit load; when the inlet smoke temperature is reduced by 10 鈩，

本文編號(hào)：1741143