=3764℃
(3)按图5-3 设t理1=2650℃
则根据t理及PCO2 PH2O查附表8得
f’’CO2=67.5% fH2O=22.2%
查表5-2得
C3空=1.54(kg/m℃) C产=1.88(kg/m3℃) Q分=12600fCO2VCO2+10800 fH2OVH2O
=12600×0.675×0.421+10800×0.222×1.14 =6314(kJ/m3)
t理 =(Qd-Q分)/[V0C产+(Ln-L0)C空]
=(17660-6314)/(2.629×1.88+0.205×1.54) =2158℃
与假设t理1=2600℃相比相差太大,计算不合乎要求。
(4)再取t理2=2500℃
则根据t理2及PCO2 PH2O查附表8得 f’CO2= 52.7% f’H2O= 14.6%
C3
空 = 1.53(kg/m℃) C产 = 1.87(kg/m3℃)
Q分=12600fCO2VCO2+10800 fH2OVH2O
=12600×0.527×0.421+10800×0.146×1.14 =4593(kg/m3)
t理=(Qd-Q分)/[V0C产+(Ln-L0)C空]
=(17660-4593)/(2.629×1.87+0.205×1.53) =2498℃
与假设t理1=2500℃基本一致,计算合乎要求。 第六章 空气消耗系数及不完全燃烧损失的检测计算
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4. 某烟煤,收到基成分为:
Car Har Oar Nar Sar Aar War 76.32 4.03.64 1.61 3.80 7.55 3.0 8
其燃烧产物分析结果为:
H2’ O2’ N2’ RO2’ CO’ 14.0 2.0 1.0 4.0 79.0 试计算:
(1) 该燃烧的RO2.max;β;K;P; (2) 验算产物气体分析的误差;
(3) 空气消耗系数n和化学不完全燃烧损失q化;
解: (1)
L0?(8.89C?26.67H?3.33S?3.33O)?0.01?0.01?(8.89?76.32?26.67?4.08?3.33?3.8?3.33?3.64) ?7.88(m3/kg)L0.O2?0.21L0?1.655(m3/kg)
VCS22.476.323.822.4ro2?(12?32)?100?(12?32)?100?1.46(m3/kg)
VHW22.4H2o?(2?18)?100?0.5(m3/kg) 12
VNN2?28?22.4100?0.79L0?6.25(m3/kg) V干
30=1.46+6.25=7.71(m/kg) Qd=30.03(MJ/kg) 所以 K?L0.O21.665V?1.46?1.13 RO2RO'(VRO2)完2.max?100(V?1.46?100?0)干7.7119
'??21?RO2.mazRO'?21?1919?0.11 2.maxP?Qd30.03?103V?7.71?3.90?103(kJ/m3)
0(2)验证分析误差:
将各烟气成分及β值代入烟气分析方程:
(1??)RO'2?(0.605??)CO'?O'2?0.185H'2?(0.58??)CH'4??1?0.11??14??0.605?0.11??2?4?0.185?1??0.11?0.58.??0?20.79成分误差: ??.20.79?2121?1%
(3) 计算空气消耗系数及不完全燃烧损失
'n?O2?(0.5CO'?0.5H2'?2CH'4)K?RO'2?CO'?CH'?14???4?0.5?2?0.5?1?0?1.14?16?1 ?1.14qRO'2.max126CO'?108H2'化?P?RO'CO'?100%2??193895?126?2?108?114?2?100%
?11%某高炉煤气,干成分为:
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5.
CO2 CO H2 N2 CH4 10.66 29.0.27 1.65 96 57.46
煤气温度为20℃。燃烧产物成分经分析为(%):
O2’ N2’ RO2’ CO’ 14.0 9.0 1.2 75.8
试采用各种计算公式n值,并比较之
解:
L1?11m0.o2??100????2CO?2H2?????n??4???CnHm?32H2S?O2?????0.5?29.96?0.5?1.65?2?0.27?0?0??0.01 ?0.1635?m3/m3?V??CO??n?C?1RO2nHm?CO2?H2S?100??29.96?0.27?10.66?0??0.01
?0.4089?m3/m3?烟气成分:RO,= 14.0 O,,2= 9.0 CO,= 1.2 N2= 75.8 所以:K?L0.O2V?0.1635RO0.4089?0.4
2(1) 利用氧平衡计算:
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'n?O2?(0.5CO'?0.5H2'?2CH'?4K?RO'2?CO'?CH'?14?9??0.5?1.2?0.5?0?2?0?0.4?15.2?1
?2.38
(2) 利用氮平衡计算:
n?1.1?7921?(O'2?0.5CO'?0.5H2?2CH'4'N'N''2?(RO2?CO?CH4) 2?VRO2?100?2.38
6. 某天然气在纯氧中燃烧,烟气成分为(%):
H2’ O2’ CO2’ CO’ CH4’ 25.0 24.49.0 0.5 1.5 0 求氧气消耗系数。
解: 查表6-3:天然气在富氧中燃烧,取K=2.0
n?O'2?(?0.5CO'?0.5H2'?2CH'?4KRO'?12?CO'?CH'4 ?0.5??0.5?24?0.5?49?2?1.5?2?(25?24?1.5)?1 ?0.614 15