化学反应工程第三章习题课

PAGEPAGE3第三章习题课2、对某一反应器用阶跃法测得出口处不同时间的示踪剂质量浓度变化关系为：t/min0246810121416c/kg·m-300.050.110.20.310.430.480.500.50F(t)，E(t)t，2t解:c=0.5kgm-30tc

t2c00000000020.050.050.10.050.20.4400000000020.050.050.10.050.20.440.110.160.220.060.481.9260.20.360.40.091.086.4880.310.670.620.111.7614.08100.431.10.860.122.424120.481.580.960.051.214.4140.52.081.00.020.567.84160.52.581.0000∑7.6869.12tc0

7.68min2t2ct c0

t269.127.68210.14min23、请将习题一中停留时间分布规律用对比时间θ作变量，求F(θ)，E(θ)，，2。θt

FF Ett

2 2 θ 2

VV0

VV0

33.331.5t/min0t/min01020304050607080c/kg·m-3036543210Et00.41660.8330.6940.55560.41660.27660.1390EFF 0 0.0625 0.25 0.4792 0.6667 0.8125 0.9167 0.9792 1.0 t 2

33.33133.33272.222tθ 2

33.332A04、应用习题一的反应器，进行A+B→D反应，已知cA0

=c =20mol·m-3，动力学方程为B0r=0.005ccA A

mol·m-3min-1，请用凝集流模型计算反应器出口物料中A组分的转化率，A B 并求c，c，c A B 本题若用PFR及CSTR模型计算时，物料出口中A组分的转化率是多少?解①凝集流模型：x A0

x FAix dx

x

c x dxtc

A

A A A0

A AA00 rAx dx

0 0.005ccAB10x

0.005c2 A0t

1x 2At10A

A A1

x

x i 0 1x 2 xA

A t

Ai ti

10时间t/min c/kg·m-3

tx i i000000i0000001030.1250.50.1250.06252060.3750.6670.250.166753050.58330.750.20830.1562254040.750.80.16670.133365030.8750.8330.1250.1041256020.95830.8570.08330.07138817011.00.8750.04170.03648758001.00.88900∑240.7308356

Fi

x FAi ix A0

x F0.7308Ai c cA

c 1xA0

20

1

5.384molm3c c xD A0

200.730814.616molm3②PFR模型计算时：V VV d dx

33.33minc

xA

1 xAdAxxA00 rAx dx

c 0A010x

1x 2A

A A

33.330 1xA

2 1xAx 0.7692A③CSTR模型计算VVV0 c

33.33min11

2x210x2x2 A0r

A0.005cA0

x

A33.332Af2x 0.5821A

A0 A A6、用习题5的条件，采用轴向扩散模型，计算其Pe值与出口物料中A组分的转化率。解t1 满足闭闭式边界条件2 2 1Pe2 tθ t

0.245

1Pe

Pe 试差得Pe6.99314kPe 140.0514kPe4expPe

1.39762 2x 1 A 12expPe12expPe 2 2 41.3976exp6.9932 21 11.39762exp1.39766.99311.39762exp1.39766.993 2 2 10.24220.75787、设E(θ)、F(θ)分别为某流动反应器的停留时间分布密度函数和停留时间分布函数，θ为对比时间。PFR，试求：(a)F(1)，(b)E(1)，(c)F(0.8)，(d)E(0.8)，(e)E(1.2)CSTR，试求：(a)F(1)，(b)E(1)，(c)F(0.8)，(d)E(0.8)，(e)E(1.2)若反应器为一非理想流动反应器，试求(aF(∞，(b)F(0，(c)E(∞，(d) F，(e) E0 0解(1)对PFR，F(1)=1，E(1)=∞，F(0.8)=0，E(0.8)=0，E(1.2)=0对CSTR，F1e(2) F1e10.6321E1