【摘要】：間接空冷系統(tǒng)設(shè)計(jì)的優(yōu)劣直接關(guān)系到火電廠的安全運(yùn)行和經(jīng)濟(jì)效益,因此對其進(jìn)行塔型優(yōu)化研究是十分必要的。 借助Fluent數(shù)值模擬軟件,以某600MW間接空冷機(jī)組為例,模擬研究了環(huán)境風(fēng)對間接空冷塔內(nèi)的空氣流場產(chǎn)生的影響。結(jié)果表明,無風(fēng)情況下,塔內(nèi)空氣流場呈現(xiàn)出均勻?qū)ΨQ性。當(dāng)環(huán)境風(fēng)存在時(shí),塔內(nèi)空氣流動發(fā)生偏斜,風(fēng)速達(dá)到一定程度時(shí),部分空氣不能從空冷塔出口流出,發(fā)生“倒灌”現(xiàn)象,同時(shí),在環(huán)境風(fēng)的作用下,部分空氣會從空冷塔底部的一側(cè)散熱器流入,從另一側(cè)散熱器流出,而未從空冷塔的出口流出,形成穿膛風(fēng)。環(huán)境風(fēng)速越高,“倒灌”現(xiàn)象和穿膛風(fēng)現(xiàn)象越嚴(yán)重,這對機(jī)組的安全性和經(jīng)濟(jì)性產(chǎn)生了十分惡劣的影響。 根據(jù)間接空冷系統(tǒng)熱力特性和阻力特性的數(shù)學(xué)模型,對間接空冷塔的塔型進(jìn)行了優(yōu)化研究,應(yīng)用VC++軟件,開發(fā)了間接空冷塔塔型優(yōu)化研究程序,用實(shí)例進(jìn)行了分析和研究。分析發(fā)現(xiàn),空氣總流量L越大,空氣出塔速度va2越小,容易發(fā)生“倒灌”現(xiàn)象；冷卻水出塔溫度tw2隨空氣總流量L、循環(huán)冷卻水總量G的增加而降低,對應(yīng)的凝汽器背壓Pc越小,機(jī)組性能越好；空冷塔有效高度He越大,空冷塔抽力△PH越大,空氣出塔速度va2越大,空冷塔的穩(wěn)定性越好。由于空冷散熱器和冷卻水循環(huán)泵等供水設(shè)備的投資運(yùn)行費(fèi)用較高,實(shí)際應(yīng)用中,建議選取空氣總流量L較大、循環(huán)冷卻水總量G較小、冷卻三角個數(shù)n較小、空冷塔有效高度He較大的塔型。 本文可結(jié)合經(jīng)濟(jì)性分析,求得技術(shù)上最合理,經(jīng)濟(jì)效果最好的塔型組合,具有很高的實(shí)用價(jià)值。
[Abstract]:The design of indirect air-cooling system is directly related to the safe operation and economic benefit of the thermal power plant, so it is very necessary to study the optimization of the tower form of the indirect air-cooling system. With the help of Fluent numerical simulation software, the influence of ambient wind on the air flow field in an indirect air cooling tower was studied by taking a 600MW indirect air cooling unit as an example. The results show that the air flow field in the tower shows uniform symmetry when there is no wind. When the environmental wind exists, the air flow in the tower is skewed, and when the wind speed reaches a certain extent, part of the air cannot flow out from the outlet of the air cooling tower, resulting in the phenomenon of "reverse irrigation". At the same time, under the action of the environmental wind, Some air will flow in from one side of the bottom of the air cooling tower, from the other side of the radiator, and not from the outlet of the air cooling tower, forming the perforating air. The higher the environmental wind speed, the more serious the phenomenon of "reverse irrigation" and "rifling wind", which has a very bad effect on the safety and economy of the unit. According to the mathematical model of thermal and resistance characteristics of indirect air-cooling system, the optimization of tower type of indirect air-cooling tower is studied. Using VC software, a program for optimization of indirect air-cooled tower type is developed, and an example is given to analyze and study the optimization program of indirect air-cooling tower type. It is found that the larger the total air flow L, the smaller the velocity va2 of the air out of the tower, which is prone to the phenomenon of "reverse irrigation". The cooling water outlet temperature (tw2) decreases with the increase of total air flow rate (L) and total circulating cooling water (G). The smaller the relative condenser backpressure (Pc), the better the unit performance. The greater the effective height He of the air cooling tower is, the greater the suction PH of the air cooling tower is, the greater the air output speed va2 is, and the better the stability of the air cooling tower is. Because of the high investment cost of water supply equipment such as air cooling radiator and cooling water circulating pump, it is suggested that the total air flow rate L is larger, the total circulation cooling water G is smaller, and the number of cooling triangles n is smaller than that of air cooling radiator and cooling water circulating pump. The effective height of air cooling tower is larger than that of He. Combined with the economic analysis, this paper can obtain the most reasonable technical and economic effect of the tower combination, which has a high practical value.
【學(xué)位授予單位】：華北電力大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TM621

【參考文獻(xiàn)】

相關(guān)期刊論文 前3條

1 石磊;石誠;余U，

本文編號：2469092