本文選題：直接空冷系統(tǒng) + 軸流風(fēng)機(jī)群��； 參考：《華北電力大學(xué)》2015年碩士論文

【摘要】：直接空冷系統(tǒng)節(jié)水效果明顯,在富煤缺水地區(qū)應(yīng)用十分廣泛。軸流風(fēng)機(jī)群的經(jīng)濟(jì)運(yùn)行是直接空冷機(jī)組經(jīng)濟(jì)運(yùn)行的重要環(huán)節(jié),也是降低廠用電的一個(gè)重要途徑,因而對(duì)風(fēng)機(jī)群的運(yùn)行進(jìn)行優(yōu)化具有重要意義。本文以典型2×600MW直接空冷機(jī)組為例,通過(guò)CFD數(shù)值模擬,研究了不同風(fēng)向、不同風(fēng)速下空冷島流動(dòng)傳熱特性和機(jī)組凈功率隨不同區(qū)域風(fēng)機(jī)群轉(zhuǎn)速的變化規(guī)律。研究結(jié)果表明,迎風(fēng)面風(fēng)機(jī)受環(huán)境風(fēng)影響比較大。以額定風(fēng)機(jī)轉(zhuǎn)速79rad/s為基準(zhǔn),當(dāng)提高迎風(fēng)面風(fēng)機(jī)轉(zhuǎn)速時(shí),風(fēng)機(jī)入口平均溫度增加,冷卻空氣流量變化不大,空冷島的流動(dòng)傳熱特性略微變差；而降低轉(zhuǎn)速時(shí)除了迎風(fēng)面空冷單元,相鄰一排空冷單元冷卻換熱效果也變差,故即使風(fēng)機(jī)功耗減少,電廠的經(jīng)濟(jì)性依然下降。環(huán)境風(fēng)從空冷島側(cè)面吹來(lái),在風(fēng)速較小時(shí)提高兩側(cè)風(fēng)機(jī)轉(zhuǎn)速可使空冷島的流動(dòng)傳熱特性有所改善,電廠凈功率小幅增加,而環(huán)境風(fēng)速比較大時(shí)電廠凈功率減少。當(dāng)提高迎風(fēng)面以外其余風(fēng)機(jī)轉(zhuǎn)速至86.9rad/s時(shí),冷卻空氣流量增加,空冷島的冷卻換熱效果變好,電廠凈功率變大,這說(shuō)明電廠的經(jīng)濟(jì)性得到了提高；環(huán)境風(fēng)速越大,凈功率增加量越小,當(dāng)風(fēng)速達(dá)到15m/s左右時(shí),空冷島換熱效果變差,電廠經(jīng)濟(jì)性降低。本文研究發(fā)現(xiàn),環(huán)境風(fēng)速不大時(shí)可以通過(guò)提高迎風(fēng)面風(fēng)機(jī)之外的其余風(fēng)機(jī)轉(zhuǎn)速來(lái)改善空冷島的流動(dòng)傳熱特性,進(jìn)而提高直接空冷機(jī)組的經(jīng)濟(jì)性。
[Abstract]:Direct air cooling system has obvious water-saving effect and is widely used in areas rich in coal and water shortage.The economic operation of axial-flow fan group is an important link of direct air-cooled unit's economic operation, and also an important way to reduce the auxiliary power consumption, so it is of great significance to optimize the operation of fan group.Taking a typical 2 脳 600MW direct air-cooled unit as an example, the flow heat transfer characteristics of air-cooled island and the variation of unit net power with different regional fan group speed under different wind direction and different wind speed are studied by CFD numerical simulation.The results show that the upwind fan is greatly affected by the environmental wind.On the basis of rated fan speed 79rad/s, when the speed of upwind fan is increased, the inlet average temperature of fan increases, the cooling air flow rate changes little, and the flow heat transfer characteristic of air-cooled island becomes worse slightly, but when the speed is reduced, the air cooling unit is only upwind surface air cooling unit.The cooling and heat transfer effect of the adjacent air cooling unit also becomes worse, so even if the fan power consumption is reduced, the economy of the power plant is still decreased.When the ambient wind blows from the side of the air-cooled island, when the wind speed is small, the flow heat transfer characteristics of the air-cooled island can be improved, the net power of the power plant will increase slightly, and the net power of the power plant will decrease when the wind speed is relatively large.When the rotating speed of the other fans outside the upwind surface is increased to 86.9rad/s, the cooling air flow rate increases, the cooling heat transfer effect of the air-cooled island becomes better, and the net power of the power plant becomes larger, which indicates that the economy of the power plant has been improved and the environmental wind speed is higher.The smaller the net power increase is, when the wind speed reaches 15m/s, the heat transfer effect of air-cooled island becomes worse and the economy of power plant decreases.In this paper, it is found that when the ambient wind speed is small, the flow heat transfer characteristics of the air-cooled island can be improved by increasing the rotating speed of the fan other than the upwind fan, and thus the economy of the direct air-cooled unit can be improved.
【學(xué)位授予單位】：華北電力大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TM621

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 戴振會(huì);孫奉仲;王宏國(guó);;國(guó)內(nèi)外直接空冷系統(tǒng)的發(fā)展及現(xiàn)狀[J];電站系統(tǒng)工程;2009年03期

2 賈寶榮;楊立軍;杜小澤;楊勇平;;不同風(fēng)向條件下空冷島運(yùn)行特性的數(shù)值模擬[J];現(xiàn)代電力;2009年03期

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本文編號(hào)：1757572