吳乃新 汪麗芬 王恩祿
摘要: 針對(duì)富氧燃燒鍋爐增加了尾部再循環(huán)煙氣和空氣分離單元抽取的氧氣特點(diǎn),比較了常規(guī)空氣燃燒鍋爐焓溫表計(jì)算方法與富氧燃燒方式下焓溫表計(jì)算內(nèi)容的區(qū)別,分析了富氧燃燒鍋爐循環(huán)煙氣焓、分離氧氣焓和爐膛進(jìn)口熱燃燒氣焓隨氧氣的體積分?jǐn)?shù)變化的特性,給出了富氧燃燒鍋爐煙氣焓溫表的計(jì)算方法,為富氧鍋爐熱力計(jì)算提供了理論依據(jù).
關(guān)鍵詞:
空氣燃燒方式; 富氧燃燒; 燃燒氣; 焓溫表
中圖分類號(hào): TM 621.2文獻(xiàn)標(biāo)志碼: A
Study on Flue Gas Enthalpytemperature Characteristics of Oxyfuel Combustion
WU Naixin1, WANG Lifen2, WANG Enlu2
(1.Shanghai Boiler Works, Ltd., Shanghai 200245, China;
2.Shanghai Jiaotong University, Shanghai 200240, China)
Abstract:
In terms of the addition of recycled flue gas from the rear of boiler and separated oxygen from the air separation unit,comparisons were conducted between the calculation methods of enthalpy for conventional airfuel combustion and those for the oxyfuel combustion.The variation of recycled flue gas enthalpy,separated oxygen enthalpy and inlet gas enthalpy of the furnace with the oxygen concentration was analyzed in the oxyfuel combustion boiler.And the calculation methods of flue gas enthalpy for oxyfuel combustion was proposed,which could provide the theoretical basis for the thermal calculation of oxygenenriched boiler.
Keywords:
airfuel combustion; oxyfuel combustion; combustion gas; enthalpytemperature table
富氧燃燒鍋爐與常規(guī)空氣燃燒鍋爐相比其最大的特點(diǎn)在于增加了尾部再循環(huán)煙氣和空氣分離單元抽取的氧氣[1-3].此時(shí),進(jìn)入氣氣預(yù)熱器的不再是冷空氣,而是上述循環(huán)煙氣和分離氧氣,稱為燃燒氣.
常規(guī)空氣燃燒鍋爐是基于空氣燃燒進(jìn)行的,而富氧燃燒鍋爐是基于燃燒氣進(jìn)行的.常規(guī)空氣燃燒鍋爐焓溫表的計(jì)算方法無(wú)法直接用于計(jì)算富氧燃燒鍋爐煙氣焓溫表,因此,開(kāi)展富氧燃燒鍋爐煙氣焓溫特性研究非常必要.
本文根據(jù)常規(guī)空氣燃燒鍋爐煙氣焓溫表計(jì)算流程[4-6],進(jìn)行了富氧燃燒鍋爐煙氣焓溫特性計(jì)算模型研究,并結(jié)合具體實(shí)例進(jìn)行了分析比較,所得研究結(jié)果可為富氧鍋爐熱力計(jì)算提供理論依據(jù).
3結(jié)論
富氧燃燒受熱面處煙氣焓由相同溫度時(shí)爐膛燃燒產(chǎn)物下的實(shí)際煙氣焓和從爐膛到指定受熱面處漏風(fēng)焓組成;富氧燃燒時(shí)排煙焓的計(jì)算方法不同于常規(guī)燃燒,焓溫表計(jì)算時(shí)增加了總?cè)紵龤忪?、再循環(huán)煙氣焓和分離氧氣焓.
富氧燃燒時(shí),當(dāng)燃燒氣中氧氣的體積分?jǐn)?shù)由22%增加到30%時(shí),循環(huán)煙氣焓減小,分離氧氣焓增大,熱燃燒氣焓減小,鍋爐的排煙體積、排煙焓均減小.
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