4万吨/年甲烷氯化物工程项目中固定双管板换热器设计
设计温度下,换热管材料20钢的屈服点?st?245MPa 系数 Cr=?2Et2?200?103=3.14?=126.88 (4-4) t?s245故
lcr900??110.3?Cr,所以 i8.16???=?st(1-lcr/i245110.3)=?(1-)?69.25MPa (4-5) cr22Cr22?126.88(4) 系数计算
管板开孔后的面积:
?d23.14?252A1?A?n?4?125600?86?4?83406.25mm2 换热管排布采用正三角形排列,故管板布管区面积:
At?0.866na2?Ad?0.866?86?322?0?76263.4mm2 管板布管区的当量直径:D4At4?76263.4t???3.14?311.7mm系数 ??A1A?83406.25125600?0.644 壳体不带波形膨胀节,故换热管束与圆筒刚度比:
Q?Etna86?144.44EA??1.62 ss7649.04系数 ??na86?144.44A?83406.25?0.149 1系数 ?0.6Qs?0.4???0.6??0.4?0.60.6?1.620.644?0.49?2.77 系数?1t?0.4?1??????0.6?Q? ?0.4??1?0.149??10.644??0.6?1.62? =3.8 管板布管区的当量直径与壳程圆筒内径之比:
?Dtt?D?311.7?0.78 i40025
(4-6)
(4-7) (4-8)
(4-9) 4-10) 4-11) 4-12) 4-13)
4-14) (((((4万吨/年甲烷氯化物工程项目中固定双管板换热器设计
(5) 法兰力矩
法兰材料选用16Mn锻件,查文献[4]表6知 ???f?178MPa
???ft?150MPa
预紧状态下的法兰力矩:
35=159932.5N/mm ( 4-15) Ma?FGLG?45169.5×操作状态下的法兰力矩:
MP?FDLD?FTLT?FGLG?125600?50?45169.5?53.09?94906.5?59 (4-16) 1.1716??107N/mm(6) 管板
取管板刚度削弱系数?=0.4 假定管板计算厚度 δ=50mm,则
?DK??1.318i???
Etna??Ep?L???1/2?40086?144.4? ( 4-17) ???1.318?50?0.4?1800?50?????2.491/2管板周边不布管区无量纲宽度
k?K?1??t??2.49??1?0.78??0.55 (4-18) (7) 法兰 法兰宽度 bf?565?400?82.5mm ( 4-19)
22?''f?h630管箱法兰厚度 ?''f?30mm 故??0.015, ??0.085
Di400Di400?Df?Di查文献[5]图知,?''?0.0015,则管箱圆筒与法兰的旋转刚度参数:
26
4万吨/年甲烷氯化物工程项目中固定双管板换热器设计
3?1?2Ef''bf?2?f''?Kf''??????''Eh?12?Di?bf?Di????3?1?2?1.97?105?82.5?2?30?5 ???????0.0015?1.97?10? (4-20)
12?400?82.5400??????52.2?'?630由s??0.015,f??0.085查文献[5]图知?'?0.0015 Di400Di400?K12Ef?bf?2??3?f???12???f????Es???Di?bf??Di??????1?2?1.91?105?82.5?2?30?3?12?????400?82.5??400???0.0015?1.91?105?? ??50.62旋转刚度参数Kf?Kf??50.62,则 旋转刚度无量纲参数K?Kff?4K?3.14?50.62t4?11193?0.00355 由KDft?D?565400?1.4125 查文献[4]图得Y=6 i按K,K[5]f查文献图4-25得m1?0.25m1=0.25,m2?3.1,所以系数 ??m1KK?0.25f2.49?0.00355?28.28 按K,Kf查文献[5]图4-29得G2=1.6,则
M1?m10.252K?Q?G??0.0156 2?2?2.49??1.62?1.6?按K,Q查文献[5]图4-28得G3=0.053 法兰力矩折减系数 ??KfK?0.003550.00355?0.053?0.0628 f?G3管板边缘力矩变化系数?M?1?1?0.968 ??Kf?0.628?50.62K52.21f??27
(4-21) 4-22)
(4-23) (4-24)
(4-25)
(4-26)
( 4万吨/年甲烷氯化物工程项目中固定双管板换热器设计
法兰力矩变化系数: ?Mf?Kf??M?50.62?0.923?0.939 (4-27) Kf??52.214.1.2 危险组合工况的计算和校核
(1) 壳程压力作用下的危险组合 (不计入膨胀差)
??0,??Et?0
壳程设计压力Ps?0.5MPa
当量压力组合Pc?Ps?Pt?1????0.5MPa 有效压力组合:
Pa??sps??tpt???Et?6.22?0.5 ?3.11MPa基本法兰力矩系数:
Mm?4Mm??D3?4?6.2648?1063.11?0.0604 iPa0.664?3.14?4003?管板边缘力矩系数:M?Mm???M?M1 ?0.0604?0.978?0.0156?0.0757
管板边缘剪切系数:????M?28.28?0.1638?2.568 管板总弯矩系数:m?m1??m21???0.25?2.568?3.11?5.556?2.301 由m>0知G1e?3?m3?0.4?2.301K?2.49?1.109 按K和m查文献[5]图31(a)知G1i?Gle
系数G1取G1e与G1i两者中较大值,即G1=G1e?1.109 管板布管区周边剪切应力系数: ???p?11?4Q?G 228
(4-28) (4-29)
(4-30)
(4-31)
(4-32) (4-33)
(4-34) (4-44)
4万吨/年甲烷氯化物工程项目中固定双管板换热器设计
11?2.568???0.277 41.62?1.61?1???G1?pG1 (4-45) 管板径向应力系数: ?r????4Q?G2?0.277?1.109?0.307
管板布管区周边处径向应力系数:?r??3m?1???3m???p (4-46)
4K?Q?G2?K ?3?2.301?0.277?0.768 2.49壳体法兰力矩系数:Mws???Mm??MfM1 (4-47)
?0.0628?0.0604?0.939?0.0156??0.011
??① 管板应力校核
??D?管板径向应力:?r??r?Pa?i? (4-48)
????0.664?400??0.307?3.11?????101.43MPa
0.4?50?即?r?1.5???r?1.5?167?250MPa,径向应力满足要求。 管板布管区周边处的径向应力:
2???Pkk?a?r????r?1????m2mt22???D?2?m??i????? (4-49)
?2?0.550.664?3.110.552??0.768??1???0.4?2.3012?2.301?108.33MPat???400?2?2.301????
50????2 即?r??1.5???r?1.5?167?250MPa,满足要求。 管板布管区周边剪切应力:?p??Pa?D??p??t????? (4-50) ?0.664?3.11311.7?0.277?0.450 ?8.91MPa?29