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《燃料与燃烧》部分习题答案

《燃料与燃烧》习题解答第一篇 燃料概论1. 某种煤的工业分析为:M ar =3.84, A d =10.35, V daf =41.02, 试计算它的收到基、干燥基、干燥无灰基的工业分析组成。

解:干燥无灰基的计算:02.41=daf V98.58100=-=daf daf V Fc ;收到基的计算 ar ar ar ar V M A FC ---=10036.35100100=--⨯=arar daf ar A M V VA ar = 9.95 FC ar = 50.85干燥基的计算: 35.10=d AV d = 36.77;88.52100=--=d d d A V FC2. 某种烟煤成分为:C daf =83.21 H daf =5.87 O daf =5.22 N daf =1.90 A d =8.68 M ar =4.0; 试计算各基准下的化学组成。

解:干燥无灰基:80.3100=----=daf daf daf daf daf N O H C S收到基: 33.8100100=-⨯=ard ar M A A95.72100100=--⨯=arar daf ar M A C CH ar =5.15 O ar =4.58 N ar =1.67 S ar =3.33 M ar =4.0干燥基: 68.8=d A 99.75100100=-⨯=ddaf d A C C 36.5913.0=⨯=daf d H H 77.4913.0=⨯=daf d O ON d = N daf ×0.913 =1.7447.3913.0=⨯=daf d S S干燥无灰基:C daf =83.21 H daf =5.87 O daf =5.22 N daf =1.90 S daf =3.803. 人工煤气收到基组成如下:计算干煤气的组成、密度、高热值和低热值;解:干煤气中: H 2,d = 48.0×[100/(100-2.4)]=49.18 CO ,d = 19.3×1.025=19.77 CH 4,d = 13.31 O 2,d = 0.82 N 2,d = 12.30 CO 2,d = 4.61ρ=M 干/22.4=(2×49.18%+28×19.77%+16×13.31%+32×0.82%+28×12.30%+44×4.61%)/22.4= 0.643 kg/m 3Q 高 =4.187×(3020×0.1977+3050×0.4918+9500×0.1331)=14.07×103 kJ/m 3= 14.07 MJ/ m 3Q 低 =4.187×(3020×0.1977+2570×0.4918+8530×0.1331)=12.55×103 kJ/m 3= 12.55 MJ/ m 3第二篇 燃烧反应计算第四章 空气需要量和燃烧产物生成量5. 已知某烟煤成分为(%):C daf —83.21,H daf —5.87, O daf —5.22, N daf —1.90,S daf —3.8, A d —8.68, W ar —4.0,试求:(1) 理论空气需要量L 0(m 3/kg );(2) 理论燃烧产物生成量V 0(m 3/kg );(3) 如某加热炉用该煤加热,热负荷为17×103kW ,要求空气消耗系数n=1.35,求每小时供风量,烟气生成量及烟气成分。

解:(1)将该煤的各成分换算成应用成分:%33.81004100%68.8100100%=-⨯=-⨯=ar d ar W A A%95.72100433.8100%21.83100100%=--⨯=--⨯=ar ar daf ar W A C C%15.5%8767.087.58767.0%=⨯=⨯=daf ar H H %58.4%8767.022.58767.0%=⨯=⨯=daf ar O O %66.1%8767.09.18767.0%=⨯=⨯=daf ar N N %33.3%8767.080.38767.0%=⨯=⨯=daf ar S S%4=ar W计算理论空气需要量L 0:()kgm O S H C L /81.701.058.433.315.5895.723821.0429.11100183821.0429.1130=⨯⎪⎭⎫⎝⎛-+⨯+⨯⨯⨯=⨯⎪⎭⎫ ⎝⎛-+⨯+⨯⨯=(2)计算理论燃烧产物生成量V 0:()kgm L N W H S C V /19.881.779.0224.02866.1184215.53233.310095.72100791004.22281823212300=⨯+⨯⎪⎭⎫⎝⎛++++=+⨯⎪⎭⎫ ⎝⎛++++=(3) 采用门捷列夫公式计算煤的低发热值:Q 低= 4.187×[81×C+246×H -26×(O -S )-6×W]]= 4.187×[81×72.95+246×5.15-26×(4.58-3.33)-6×4]= 29.80(MJ/m 3) 每小时所需烟煤为:()h kg Q m /10053.2298093600101736001017333⨯=⨯⨯=⨯⨯=每小时烟气生成量:())/(1024.281.735.019.8205334h m V m V n tol ⨯=⨯+⨯=⨯=每小时供风量:h m mnL L tol /1016.281.735.12053340⨯=⨯⨯==计算烟气成分: )/(1080.220531004.221295.721004.2212332h m m C V co ⨯=⨯⨯=⨯⨯=)/(8.461004.223232h m m S V so =⨯⨯=)/(10296.1)1004.22182(332h m m W H V o H ⨯=⨯⨯+=)/(10714.179.01004.2228342h m L m N V n N ⨯=+⨯⨯=)/(10188.1)(100213302h m m L L V n o ⨯=⨯-⨯= 计算烟气百分比组成:CO 2'=12.45% SO 2'=0.21% H 2O '=5.73% N 2'=76.36% O 2'=5.25%6. 某焦炉干煤气%成分为:CO —9.1;H 2—57.3;CH 4—26.0;C 2H 4—2.5;CO 2—3.0; O 2—0.5;N 2—1.6;煤气温度为20℃。

用含氧量为30%的富氧空气燃烧,n=1.15,试求: (1) 富氧空气消耗量L n (m 3/m 3)(2) 燃烧产物成分及密度解:应换成湿基(即收到基)成分计算:将煤气干燥基成分换算成湿基成分: 当煤气温度为20℃,查附表5,知:g d ,H2O =18.9(g/m 3)H 2O 湿 =(0.00124×18.9)×100/(1+0.00124×18.9)= 2.29 CO 湿 =CO 干%×(100-H 2O 湿)/100=8.89同理: H 2湿=55.99 CH 4湿=25.40 O 2湿=0.49 CO 2湿=2.93 N 2湿=1.57 C 2H 4湿=2.44(1) 计算富氧燃烧空气消耗量:()332220/0.323421213.01m m O S H H C m n H CO L m n =⎪⎪⎭⎫ ⎝⎛-+⨯⎪⎭⎫ ⎝⎛+++⨯=∑ ()330/45.30.315.1m m L n L n =⨯=⨯= (2) 计算燃烧产物成分:()()()332/421.001.093.244.224.2589.810012m m CO H C n CO V m n co =⨯+⨯++=⨯+⨯+=∑ ()3322/14.1100122m m O H H C m H V m n O H =⨯⎪⎭⎫ ⎝⎛+⨯+=∑()332/43.245.37.001.057.11007010012m m L N V n N =⨯+⨯=⨯+⨯=()()330/135.045.03.03.02m m L L V n O =⨯=-⨯=烟气量为: V n =4.125(m 3/m 3)烟气成分百分比: CO 2'=10.20 H 2O '=27.60 N 2'=58.93 O 2'=3.27(3) 计算烟气密度:()3'2'2'2'2/205.14.2210027.33293.582860.271820.10444.2210032281844m kg O N O H CO =⨯⨯+⨯+⨯+⨯=⨯⨯++⨯+⨯=ρ7. 某焦炉煤气,成分同上题,燃烧时空气消耗系数n=0.8,产物温度为1200℃,设产物中O 2,=0,并忽略CH 4,不计,试计算不完全燃烧产物的成分及生成量。

解:(1)碳平衡公式:()()42.0.01.044.224.2593.289.810012222=++=⨯⨯++++=⨯+⨯+∑CO CO CO CO CO CO mn V V V V V V CO HC n CO(2)氢平衡方程式:()14.1.01.029.244.224.25299.55100122222220.22=++=⨯+⨯+⨯++=⨯⎪⎭⎫ ⎝⎛+⨯+∑O H H O H H H H m n V V V V V V O H H C m H(3)氧平衡方程式:81.05.05.05.05.09.08.001.029.25.049.093.289.8212121100121212222222.0222=++++=⨯+⨯⎪⎭⎫⎝⎛⨯+++⨯++=+⨯⎪⎭⎫ ⎝⎛+++O H CO CO O H CO CO O H CO CO O V V V V V V V V V nL O H O CO CO(4)氮平衡方程式:22.0276.31001N O V nL N =+⨯ 2272.29.08.076.301.057.1N N V V ==⨯⨯+⨯(5)水煤气反应平衡常 OH CO N CO OH CO N CO V V V V P P P P K 222222••=••=查附表6 当t=1200℃时,K=0.387387.0222=••OH CO N CO V V V V各式联立求解得: 算得百分比为:V H2 = 0.207(m 3/m 3) H 2, = 4.84 V CO = 0.153 (m 3/m 3) CO , = 3.57 V CO2 = 0.267(m 3/m 3) CO 2,= 6.24 V H2O = 0.933(m 3/m 3) H 2O ,= 21.80 V N2 = 2.72(m 3/m 3) N 2, = 63.55 V n = 4.28(m 3/m 3)8. 已知某烟煤含碳量为C ar —80(%),烟气成分经分析为(干成分)CO 2,--15(%);CO ,--3.33(%)。

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