(完整版)年产30万吨合成氨合成工段工艺设计毕业论文 下载本文

Ar =11607.770×3.357%=389.673m3 H2 =11607.770×61.874%=7182.692m3 N2 =11607.770×20.625%=2394.103m3

合成塔一出,二进物料,热交换器,冷气进出物料等于合成塔入塔物料 即:V5=V6=V7=11607.770 m3 出塔物料:V8=10212.836m3

NH3 =10212.836×16.5%=1685.118m3 CH4 =10212.836×13.223%=1350.443m3 Ar =10212.836×3.816%=389.722m3 H2 =10212.836×49.838%=5089.873m3 N2 =10212.836×16.612%=1696.563m3 合成塔生成氨含量:

=1685.118-290.194=1394.924 m3

废热锅炉进出口物料,热交换器进出口物料等于合成塔出塔的物料。 即V8=V9=V10=10212.836 m3 3.3.10 水冷器物料计算

进器物料:水冷器进气物料等于热交换器出口物料,即V10入=10212.836m3 出器物料:在水冷器中部分氨气被冷凝;由氨分离器气液平衡计算得气液比 (V÷L)=11.110,有如下方程:

==11.110

(3-6)

V11出+L11出=L10入=10212.836 (3-7)

将V11出=11.110L11出带入(3-7)得:

L11出=843.687m3 V11出=9369.149m3

出口气体组分由V11i=V11出×y11i得:

其中:NH3 =9369.149×9.376%=878.451m3

CH4 =9369.149×14.269%=1336.884m3 Ar =9369.149×4.145%=388.351m3 H2 =9369.149×54.148%=5073.307m3 N2 =9369.149×18.061%=1692.062m3

出口液体各组分由L11i=V8i-V11i

其中:NH3 =1685.118-878.451=806.667m3 CH4 =1350.443-1336.884=13.559m3

Ar =389.722-388.351=1.371m3 H2 =5089.873-5073.307=16.566m3 N2 =1696.563-1692.062=4.501m3

3.3.11氨分离器物料计算

进器物料:氨分离器进器总物料等于水冷器出口气液混合物总物料 即V11=V11出+L11出=9369.149+843.687=10212.836 m3

出器物料:气液混合物在器内进行分离,分别得到气体和液体 出器气体V12=V11出=9369.149m3 出器液体 L15=L11出=843.687m3 氨分离器出口气体放空V13=135.479m3 其中:NH3 =135.479×9.376%=12.703m3 CH4 =135.479×14.269%=19.331m3

Ar =135.479×4.145%=5.616m3

H2 =135.479×54.148%=73.359m3

N2 =135.479×18.061%=24.469m3

3.3.12 冷交换器物料计算

进器物料:进器物料等于氨分离器出口气体物料减去放空气量 V14=V12-V13=9369.149-135.479=9233.670 m3 其中:NH3 =9233.670×9.376%=865.749m3

CH4 =9233.670×14.269%=1317.552m3 Ar =9233.670×4.145%=382.736m3 H2 =9233.670×54.148%=4999.849m3 N2 =9233.670×18.061%=1667.693m3 出器物料(热气): 设热气出口温度T=17℃

查 T=17℃(由热量计算核定),p=28.42MPa气相平衡氨含量=5.9%,计算热气出口冷凝液氨时,忽略溶解在液氨中的气体。取过饱和度10% 故=1.1×5.9%=6.49% 设热气出口氨体积为a,则:

a?6.49%

9233.67?865.749?a计算得a=580.769

865.749-580.769=284.980m3 冷交换器热气出口气量及组分: 其中:NH3 =580.769m3 CH4 =1317.552m3

Ar =382.736m3

H2 =4999.849m3

N2 =1667.693m3

出口总气量 =9233.670-284.980=8948.690 m3 出口气体各组分:

NH3 =580.769÷8948.690×100%=6.490% CH4 =1317.522÷8948.690×100%=14.723% Ar =382.736÷8948.690×100%=4.277% H2 =4999.849÷8948.690×100%=55.872% N2 =1667.693÷8948.690×100%=18.636%

3.3.13 氨冷器的物料计算

进器物料:氨冷器进器物料等于冷交换器出器物料加上补充新鲜气物料V1=2956.387m3

其中:CH4 =2956.387×0.0111=32.816m3 Ar =2956.387×0.0032=9.460m3

H2 =2956.387×0.7475=2201.030m3 N2 =2956.387×0.2412=712.785m3

V18(进器气体物料)=V1+V17=2956.387+8948.691=11905.078m3 进器气体组分含量V18i=V1i+V17i 其中:NH3 580.769m3

CH4 = 32.816+1317.552=1350.368m3

Ar =9.460+382.736=392.196m3 H2 = 2201.030+4999.849=7200.879m3 N2 = 712.785+1667.693=2380.478m3

各组分百分含量:

NH3

=580.769÷11905.078×100%=4.878%

CH4 =1350.368÷11905.078×100%=11.343% Ar =392.196÷11905.078×100%=3.294% H2 =7200.879÷11905.078×100%=60.486%3 N2 =2380.478÷11905.078×100%=19.995%

进器液体等于冷交换器冷凝液氨量: =284.980 m3

进器总物料=V18+L18=11905.078+284.980=12190.058 m3

出器Ⅰ物料:已知出器Ⅰ气体中氨含量为4.411%,出器II气体中氨含量2.5%,设出器气体中氨含量为bⅠ m3

bI4.411?

11905.078?580.769?bI2.5解得 bⅠ=290.382m3 则氨冷器中冷凝液氨量: =580.769-290.382=290.387m3

氨冷器出口总液氨量: 284.980+290.387=575.367m3 氨冷器出口气量:

V2=V18-b=11905.078-290.387=11614.691 m3 其中:NH3 = 290.382m3 CH4 = =1350.368m3

Ar = =392.196m3 H2 = =7200.879m3 N2 = =2380.478m3

各组分百分含量:

NH3 =290.382÷11614.691×100%=2.501% CH4 =1350.368÷11614.691×100%=11.626%