煤气燃烧计算

一、煤气完全燃烧计算1、燃料部分单一可燃气体热效应，单位：kJ/Nm3（热效应数值摘自《工业炉设计手册第2版》P89-90，在《炼铁设计参考资料》P782也有）可燃成分H2COCH4C2H4C3H6C3H8C4H10热效应108051265035960598138693990485117875各种煤气成分列表如下：（成分如有变动，请相应调整）煤气种类H2COCH4C2H4C3H6CO2N2H2OO2C3H8C4H10∑高炉煤气2.30%23.40%0.00%0.00%0.00%14.60%54.70%5.00%0.00%0.00%0.00%100.00%焦炉煤气56.06%8.72%24.24%0.00%2.01%1.92%2.40%4.17%0.48%0.00%0.00%100.00%发生炉煤气13.33%27.40%1.50%0.00%0.00%3.80%49.60%4.17%0.20%0.00%0.00%100.00%高炉煤气与焦炉煤气混合气比例：70.00%：30.00%混合气18.428%18.996%7.272%0.000%0.603%10.796%39.010%4.751%0.144%0.000%0.000%100.00%转炉煤气1.40%56.85%0.00%0.00%0.00%17.90%19.30%4.17%0.38%0.00%0.00%100.00%天然气0.00%0.00%94.00%0.00%0.00%0.00%0.80%4.17%0.00%0.63%0.40%100.00%液化石油气0.00%0.00%0.00%0.00%0.00%0.00%0.00%4.19%0.00%47.905%47.905%100.00%请选择煤气种类：1（1高炉煤气，2焦炉煤气，3发生炉煤气，4高炉、焦炉混合煤气，5转炉煤气，6天然气，7液化石油气）所选煤气成分列表如下：H2COCH4C2H4C3H6CO2N2H2OO2C3H8C4H10∑2.300%23.400%0.000%0.000%0.000%14.600%54.700%5.000%0.000%0.000%0.000%100.00%分子当量22816284244281832445829.2381.3053kg/Nm3您选择的是高炉煤气，其低位发热值Qd==3208.62kJ/Nm3折合成千卡Qd=766.36kcal/Nm3或Qd=766.36kcal/Nm3÷1.3053kg/Nm3=587.13kcal/kg则所选煤气分子当量=2×2.300%+28×23.400%+16×0.000%+28×0.000%+42×0.000%+44×14.600%+28×54.700%+18×5.00%+32×0.000%+44×0.000%+58×0.000%=则所选煤气29.2380kg/kmol÷22.4Nm3/kmol=3208.62kJ/Nm3÷4.1868kJ/kcal=所选煤气成分=10805kJ/Nm3×2.30%+12650kJ/Nm3×23.40%+35960kJ/Nm3×0.00%+59813kJ/Nm3×0.00%+86939kJ/Nm3×0.00%+90485kJ/Nm3×0.000%+117875kJ/Nm3×0.000%=煤气燃烧计算第1页，共5页2、完全燃烧计算表设有1.000Nm3高炉煤气完全燃烧空气系数α=1.500O2N2CO2H2ON2O2合计H20.0230.012————0.023————0.023CO0.2340.117——0.234——————0.234CH40.0000.000——0.0000.000————0.000C2H40.0000.000——0.0000.000————0.000C3H60.0000.000——0.0000.000————0.000O20.0000.000————————————CO20.146————0.146——————0.146N20.547——0.483————1.030——1.030H2O0.0500——————0.050————0.050C3H80.0000.000——0.0000.000————0.000C4H100.0000.000——0.0000.000————0.000Σ1.0000.1290.4830.3800.0731.0300.0001.4830.0640.0640.2420.2420.3800.0731.2720.0641.78921.24%4.08%71.09%3.59%100.00%1.000Nm3煤气中的体积含量/Nm3CH4+2O2=CO2+2H2O2H2+O2=2H2OH2O=H2OC3H8+5O2=3CO2+4H2O2C4H10+13O2=8CO2+10H2ON2=N2当α=1.500时烟气中过剩O2量=（α-1）×理论需O2量=(1.500-1)×0.129Nm3=完全燃烧（α=1.500）计算表煤气组成生成物的体积/Nm3理论空气需要量/Nm3化学反应式C2H4+3O2=2CO2+2H2O2C3H6+9O2=6CO2+6H2O——当α=1.500时烟气中过剩N2量=过剩O2量×79/21=0.06Nm3×79÷21=CO2=CO22CO+O2=2CO2生成物总量（Nm3）生成物百分含量（％）第2页，共5页0.129Nm3/Nm3高炉煤气0.612Nm3/Nm3高炉煤气1.483Nm3/Nm3高炉煤气Va0×α0.918Nm3/Nm3高炉煤气1.789Nm3/Nm3高炉煤气3、完全燃烧实际理论燃烧温度计算实际理论燃烧温度tli计算公式如下：式中，tli：为计算的实际理论燃烧温度，℃V、c：实际燃烧产物体积及产物平均比热容，单位分别是：Nm3，kJ/(Nm3·℃)Q：煤气发热量，kJVr、cr、tr：煤气的体积、平均比热和温度，单位分别是：Nm3，kJ/(Nm3·℃)，℃Va、ca、ta：助燃空气的体积、平均比热和温度，单位分别是：Nm3，kJ/(Nm3·℃)，℃n%：燃烧室热效率，这里设定n%=100%⑴煤气平均比热计算实际烟气量V=V0＋(α-1)×Va0=1.483Nm3＋（1.500-1)×0.612Nm3=0.129Nm3理论需O2量÷21％÷1.0000Nm3=理论烟气量V0=实际空气量Va==0.612Nm3（理论空气量）×1.500=根据以上列表计算可得，这样的煤气完全燃烧时理论需氧量、理论空气量、理论烟气量以及空气过剩系数α=1.500时的实际空气量和实际烟气量如下：理论空气量Va0=理论需氧气量L0O2=0.129Nm3理论需O2量÷1.0000Nm3=1.483Nm3理论生成物量÷1.0000Nm3=注：将涉及到的单一气体平均比热计算公式列如下：单位：kJ/（Nm3·℃）（参见《炼铁设计参考资料》P776～778，《高炉炼铁工艺及计算》成兰伯主编P524～526也有）%rrraaaliQVctVctntVc2326(0.386160.22100.081810)4.1868626.9COcttt（℃）2273.1[(0.71428308.38lg153.4)]4.186820001000COtcttt（℃）23(0.31410.0424110)4.1868626.9Octt（℃）2273.1[(0.42143113.07lg55.74)]4.186830001000Otcttt（℃）2326(0.31030.0124100.0178610)4.1868626.9NCOcttt、、空气（℃）2273.1[(0.41844148.33lg65.28)]4.186830001000NCOtcttt、、空气（℃）3(0.355350.031710)4.1868100cttH2O(气)（℃）31(0.35010.0578100.26)4.1868526.9ctttH2O(气)（℃）273.11000[(0.68973850.63lg117.298.6)]4.186830001000273.1tcttttH2O(气)（℃）第3页，共5页首先设定煤气温度tr=20℃煤气的平均比热cr要根据烃类比热计算,烃类平均比热表如下：（单位：kJ/(Nm3·℃)）（参考自《硅酸盐工业热工基础》P240表4-14）温度C2H4C3H6C3H8C4H100℃1.7162.1783.8314.207100℃2.1062.5044.2954.752200℃2.3282.7974.7435.233300℃2.5293.0775.1625.715400℃2.7213.3375.5646.196500℃2.8933.5715.9166.627按照插入法计算,20℃时各种烃类平均比热计算结果如下，计算结果在下列相应温度区间列出温度区间C2H4C3H6C3H8C4H100～100℃1.79402.24323.92384.3160此行数据为20℃时各气体平均比热，其它行数据没有意义100～200℃2.15042.56264.38464.8482200～300℃2.36822.85304.82685.3294300～400℃2.56743.12905.24245.8112400～500℃2.75543.38385.63446.2822273.11000[(0.68973850.63lg117.298.6)]4.186830001000273.1tcttttH2O(气)（℃）2326(0.31120.00375100.010410)4.1868726.9Hcttt（℃）2273.11000[(0.4652585.93lg111.60.6)]4.186830001000273.1Htctttt（℃）43(0.36860.3310)4.1868726.9CHctt（℃）4273.1[(1.20533822.37lg477.1)]4.186811001000CHtcttt（℃）第4页，共5页按照上表计算的20℃时各种烃类平均比热，来计算煤气的平均比热：（单位：kJ/(Nm3·℃)）H2COCH4C2H4C3H6CO2N2H2OO2C3H8C4H102.300%23.400%0.000%0.000%0.000%14.600%54.700%5.000%0.000%0.000%0.000%1.30261.30021.57091.79402.24321.63511.30021.49041.31863.92384.3160所以煤气平均比热cr=cH2H2+cCOCO+cCH4CH4+cC2H4C2H4+cC3H6C3H6+cCO2CO2+cN2N2+cH2OH2O+cO2O2+cC3H8C3H8+cC4H10C4H10==1.3587kJ/(Nm3·℃)⑵实际理论燃烧温度计算煤气完全燃烧时空气需要量Va=0.92Nm3设定助燃空气温度ta=20℃1.3002kJ/(Nm3·℃)3208.62kJ/Nm3所以煤气发热量Q=假设燃烧废气温度等于1262.13℃根据假设，实际计算的理论燃烧温度tli=1110.85℃二者相等时，假设的废气温度即为实际理论燃烧温度tli，计算过程如下：CO2H2ON2O2∑21.24%4.08%71.09%3.59%100.00%2000℃2100℃2200℃2300℃2400℃2500℃2.29121.78211.44381.5097kJ/Nm3·℃2.45522.46992.48372.49712.50972.5214由于温度小于2000℃，下表按照插入法计算的CO2的平均比热值略过，不能使用温度区间2000～2100℃2100～2200℃2200～2300℃2300～2400℃2400～2500℃计算结果2.46432.47852.4920