降膜蒸發(fā)器改造熱平衡計(jì)算

1、蒸發(fā)熱平衡計(jì)算計(jì)算的原始數(shù)據(jù)1）新蒸汽使用壓力P=5bar（絕壓），T=155C,潛熱2102kJ/kg；32）原液NKl75g/l,質(zhì)量分率13.8%,比熱0.825KCal/kgC,to=85C,p=1270kg/m;3）出料濃度NK255g/l,質(zhì)量分率18.5%,比熱0.766Kcal/kgC,t出=90C,p3=1375kg/m5、有效溫差分配（第一次逼近值）At1=At2=At3=At4=At5=At6=39/6=6.5C6、各效濃度%o6=GB始/(GW)=1000X175/1270/(1000-28.5)=14.6%o5=0.5X(1000-28.5)X0.146/0.5X(1

2、000-28.5)-25.5=15.4%(送入蒸發(fā)系統(tǒng)的原液全部進(jìn)入VI效蒸發(fā)器，經(jīng)VI效蒸發(fā)濃縮后，分別各以50%的液量送入V效和田效。)o4=0.5X(1000-28.5)-25.5X0.154/0.5X(1000-28.5)-25.5-39=16.8%o3=0.5X(1000-28.5)X0.146/0.5X(1000-28.5)-44.0=16.1%o2=0.5X(1000-28.5)-44X0.161/0.5X(1000-28.5)-44-44=17.9%a1=0.5X(1000-28.5)-44-44X0.179/0.5X(1000-28.5)-44-44-55.1=20.8%7、

3、各效蒸水量1)第VI效熱平1w5r5=w6r6+F0C0(t6-t0)W5=W6X561+1000X0.825(61.1-85)/557.4=W6-35.4W5=W6-35.42)第V效熱平w4r4=w5r5+0.5F6cs(t5-t6)=w5r5+0.5(FoC0-W6)X(t5-t6)=(w6-35.4)X553+0.5(1000X0.825-W6)X(76.6-61.1)W4=(w6-35.4)X553+0.5(1000X0.825-W6)X(76.6-61.1)/549.2W4=0.993W6-243)I閃熱平;4）末效（第VI效）壓力P=0.1bar（絕壓），二次蒸汽溫度T6=46C

4、,汽化熱2387kJ/kg；5）傳熱系數(shù)（W/m蒸水量W總=10001-（175/1270）/（255/1375）=235.8kg/h2、總溫度差A(yù)t總=155-46=109c3、蒸發(fā)水量的分配（第一次逼近值）W1=（W1+W2+W3+W4+W5+W6）乂Ki/（Ki+Kii+Kiii+Kiv+Kv+Kvi）=235.8X1980/（1980+1580X2+1400+917+1024）=55.1kg/hW2=W3=W1XKii/Ki=55.1X1580/1980=44.0kg/hW4=W1XKiv/Ki=55.1X1400/1980=39.0kg/hW5=W1XKv/Ki=55.1X917/1

5、980=25.5kg/hW6=W1XKvi/Ki=55.1X1024/1980=28.5kg/h4、有效溫差41有二At總-41損=109-70=39c：C）:Ki=1980,Kii=1580,Kiii=1580,Kiv=1400,Kv=917,Kvi=1024,K強(qiáng)=750;26）傳熱面積（m）:Fi=1500,Fii=1500,Fiii=1500,Fiv=1500,Fv=3750,Fvi=3750,F強(qiáng)=580;7）溫度損失：蒸發(fā)器IIIIIIIVVVI沸點(diǎn)升高131199815沿管損失11111合溫度損失70C;8）為簡(jiǎn)化計(jì)算過程，計(jì)算時(shí)沒有考慮冷凝水自蒸發(fā)產(chǎn)生

6、的二次汽及熱損失，而把它們考慮為相互抵消；9）按處理流量1000kg/h進(jìn)行計(jì)算。計(jì)算IIIIIIIVVVII閃II閃III閃加熱蒸汽日存155134.511699.683.167.6161123106948166106.59790后效溫差6.56.56.56.56.56.5沸點(diǎn)升高13/3011/139/69/48/215/3二次汽溫135.5117100.584.168.646.1度12410795826757沿管損失11111加熱蒸汽658651645.8638.8632625.6熱始KCal/kg加熱蒸汽502516530540549.2557.4潛熱KCal/kg溶液沸點(diǎn)148.51

7、28109.593.176.661.1130111.595.1二次汽燃656649644636629.7623650.6644637.6二次汽潛508522533543553561520.1532.1542.0熱Ficiti=Ficiti+wiHiFici=fici-wiFici(ti-ti)=wiriFici=0.5F6c6-Wi-W2-W3=0.5(F0c0-W6)-Wi-W2-W3(忽略閃蒸進(jìn)入的水量)0.5(F0c0-W6)-Wi-W2-W3(ti-ti)=WiriWi=0.5(i000X0.825-W6)-Wi-W2-W3(i48.5-i30)/520.iWi=14.7-0.018W

8、6-0.036(W1+W2+W3)WI=14.7-0.018X28.5-0.036X143.1=14.7-0.018X28.5-0.036X143.1=9kg/h4) II閃熱平Ficiti=Fiiciitii+wiiHiiFiicii=fici-wiiFici(ti-tii)=wiirii0.5(Foco-W6)-wi-w2-w3-wi(ti-tii)=wiiriiWII=0.5(1000X0.825-W6)-W1-W2-W3-wi(130-111.5)/532.1wii=14.3-0.017w3-0.035(wi+W2+W3+wi)WII=14.34-0.01728;5-0.035(55.

9、1+44+44+9)=8.5kg/h5) III閃熱平Fiiciitii=Fiiiciiitiii+wiiiHiiiFiiiciii=fiicii-wiiiFiicii(tii-tiii)=wiii門ii0.5(F0c0-W6)-W1-W2-W3-wi-wii(tii-tiii)=wiiiriiiWIII=0.5(1000X0.825-W6)-W1-W2-W3-wi-wii(111.5-95.1)/542wiii=12.5-0.015w6-0.03(W1+W2+W3+wi+wii)wiii=12.5-0.01528.5-0.03(55.1+88+9+8.5)=7.3kg/h6)第IV效熱平W3

10、r3+WiiiHiII=W4r4+F5O5(t4-t5)W3r3+WIIIHiII=W4r4+F5O5(t4-t5)w3r3+wiiiHiii=w4r4+0.5(F0c。-W6)-W5(t4-t5)1W3r3=w4r4+0.5(F0c0-W6)-W5(t4-t5)-WIIiHiii=543(0.993W6-24)+0.5(1000義0.825-W6)-W6+35.4(93.1-76.6)-7.3義637.6=539.2W6-13032+6806.3-8.25W6-16.5W6+584.1-4654.5=514.45W6-10296W3=(514.45W6-10296)/540W3=0.953W

11、6-19.17)第III效熱平W2r2+WIiHiI=W3r31+0.5F6O6(t3-t4)=W3r31+0.5(F0c0-W6)(t3-t6)W2r2=W3r3+0.5(F0c0-W6)(t3-t4)-WiiHii=533(0.953W6-19.1)+0.5(1000X0.825-W6)(109.5-61.1)-8.5X644=508W6-10180.3+19965-24.2w6-5474=483.2W6+4310.7W2=(483.2W6+4310.7)/530=0.91W6+8.18)第II效熱平wiri+wiHi=w2r2+F3c3(t2-t3)F3C3=0.5F6C6-W3=0.5

12、(F0c0-W6)-W3wiri+wiHi=w2r2+0.5(F0C0-W6)-W3(t2-t3)=522(0.91W6+8.1)+0.5(1000X0.825-W6)-0.953W6+19.1(128-109.5)=475W6+4228.2+7631.3-9.25W6-17.6W6+353.4=448.2w6+12212.9W1門=448.2w6+12212.9-9X650.6=448.2w6+6537.5wi=(448.2w6+6537.5)/516=0.869ws+12.39)第I效熱平1Dr=W1門+F2c2(t1-t2)F2c2=0.5(F0C0-W6)-W3-W2Dr=W11+0.

13、5(Foco-W6)-W3-W2(t1-t2)=508(0.869W6+12.3)+0.5(1000X0.825-W6)-0.953W6+19.1-0.91W6-8.1(148.5-128)=441.5W6+6248.4+8456.3-10.25W6-19.5W6+391.6-18.7W6-166.1=393.1W6+14930.2D=(393.1W6+14930.2)/502=0.783W6+29.710)蒸水量W1+W2+W3+W4+W5+W6=W0.869W6+12.3+0.91ws+8.1+0.953W6-19.1+0.993W6-24+W6-35.4+W6=235.85.725W6-

14、58.1=235.8W6=51.3kg/hw5=51.3-35.4=15.9kg/hW4=0.993X51.3-24=27.0kg/hW3=0.953X51.3-19.1=29.8kg/hW2=0.91x51.3+8.1=54.8kg/hW1=0.869X51.3+12.3=56.9kg/hD=0.783X51.3+29.7=69.9kg/h10)蒸汽單耗D/w=69.9/235.8=0.296kg.汽/kg.水8、熱負(fù)荷Q1=Dr=69.9x502=35089kcalQ2=W1門=56.9X516=29360kcalQ3=w2r2=54.8x530=29044kcalQ4=w3r3=29.8

15、x540=16092kcalQ5=w4r4=27.0X549.2=14828kcalQ6=w5r5=15.9X557.4=8863kcal9、相對(duì)熱負(fù)荷g2=Q2/Q1=29360/35089=0.837g3=Q3/Q1=29044/35089=0.828g4=Q4/Q1=16092/35089=0.459g5=Q5/Q1=14828/35089=0.423g6=Q6/Q1=8863/35089=0.25310、精確分配有效溫差A(yù)ti=39/(1+g2XFiXKiZF2XK2+gsXFiXKi/F3XK3+g4XFiXKi/F4XK4+gsXFiXKi/F5XK5+geXFiXKi/F6XKe

16、)=39/I+0.837XI955XI980/(II06XI580)+0.828XI955XI980/(II06XI580)+0.459XI955XI980/(II06XI400)+0.423XI955XI980/(I800X9i7)+0.253XI955XI980/(4000XI024)Ati=5.5CAt2=5.5X0.837XI955XI980/(II06XI580)=I0.2CAt3=5.5X0.828XI955XI980/(II06XI580)=I0.ICAt4=5.5X0.459XI955XI980/(II06XI400)=6.3CAt5=5.5X0.423XI955XI980/(

17、I800X9I7)=5.5CAt6=5.5X0.253XI955XI980/(4000XI024)=I.4CII、計(jì)算結(jié)果列表IIIIIIIVVVII閃II閃III閃加熱蒸汽I55i35.5ii3.393.276.962.4溫度后效溫差5.5i0.2i0.i6.35.5i.4沸點(diǎn)升高I3ii998i5二次汽溫I36.5ii4.394.277.963.446度沿管損失iiiii加熱蒸汽658652.5644.8636630623熱始加熱蒸汽5025i653254455356i潛熱溶液沸點(diǎn)i49.5i25.3i03.286.97i.46ii27.3i05.288.9二次汽燃657649640.56

18、34627.5623649.564i.5635二次汽潛50652353854755656i522536546熱W4=(w6-35.4)X556+0.5(1000X0.825-W6)X(76.6-61.1)/553W4=0.991W6-243) I閃熱平Ficiti=Ficiti+wiHiFici=fC1-wiF1C1(t1-ti)=wiriFiC1=0.5F6c6-wi-w2-w3=0.5(FoC0-w6)-wi-w2-w3(忽略閃蒸進(jìn)入的水量)0.5(FoC0-w6)-w1-w2-w3(t1-ti)=wiriwi=0.5(1000X0.825-w6)-w1-w2-w3(149.5-127.3

19、)/522wi=14.7-0.021w6-0.043(w1+w2+w3)WI=17.5-0.021X51.3-0.043X141.5=10.3kg/h4) II閃熱平Ficiti=Fiiciitii+wiiHiiFiicii=fici-wiiFici(ti-tii)=wiirii0.5(F0c0-w6)-w1-w2-w3-wi(ti-tii)=wiiriiwii=0.5(1000X0.825-w6)-w1-w2-w3-wi(127.3-105.2)/536wii=17.0-0.021ws-0.041(w1+w2+w3+wi)WII=17.0-0.0215求3-0.041(56.9+54.8+2

20、9.8+10.3)=9.7kg/h5) iii閃熱平Fiiciitii=Fiiiciiitiii+wiiiHiiiFiiiciii=fiicii-wiiiFiicii(tii-tiii)=wiiiriii0.5(F0c0-w6)-w1-w2-w3-wi-wii(tii-tiii)=wiiiriiiwiii=0.5(1000X0.825-w6)-w1-w2-w3-wi-wii(105.2-88.9)/522wiii=12.9-0.016w6-0.03(w1+w2+w3+wi+wii)WIII=12.9-0.01651.3-0.031(56.9+54.8+29.8+10.3+9.7)=7.1kg/

21、h6)第iV效熱平1w3r3+wiiiHiii=w4r4+F5c5(t4-t5)w3r3+wiiiHiii=w4r4+F5c5(t4-t5)w3r3+wiiiHiii=w4r4+0.5(F0c0-w)-w5(t4-t5)w3r3=w4r4+0.5(F0c0-w6)-w5(t4-t5)-wiiiHiii=547(0.991W6-24)+0.5(1000義0.825-w)-W6+35.3(86.9-71.4)-7.1義635=542.7w6-13128+6393.8-7.75ws-15.5w6+547.2-4508.5=519.45w6-10695.5w3=(519.45w6-10695.5)/5

22、44W3=0.955W6-19.77)第iii效熱平1w2r2+wiiHii=w3r3+0.5F6c6(t3-t4)=w3r3+0.5(F0c0-w6)(t3-t6)1w2r2=w3r3+0.5(F0c0-w6)(t3-t6)-wiiHii=538(0.955W5-19.7)+0.5(1000X0.825-w)(103.2-61.0)-9.7X641.5=513.8w6-10598.6+17407.5-21.1w6-6222.6=492.7w6+586.3W2=(492.7W6+586.3)/532=0.926wb+1.18)第II效熱平.1l八，、Wiri+WlHl=W2r2+F3C3(t2

23、-t3)F3C3=0.5F6C6-W3=0.5(F0c0-W6)-W31W1r1+WIHi=W2r2+0.5(F0C0-W6)-W3(t2-t3)=523(0.926W6+1.1)+0.5(1000X0.825-ws)-0.955W6+19.7(125.3-103.2)=484.3W6+575.3+9116.25-11.05wb-21.1W6+435.4=452.2w6+10127W1門=452.2w6+10127-10.3X649.5=452.2w6+3437.2wi=(452.2w6+3437.2)/516=0.876w5+6.669)第I效熱平1Dr=W1門+F2c2(t1-t2)F2c

24、2=0.5(F0C0-W6)-W3-W2Dr=W1門+0.5(F0C0-W6)-W3-W2(t1-t2)=506(0.876wb+6.66)+0.5(1000X0.825-W6)-0.955W6+19.7-0.926W6-1.1(149.5-125.3)=443.3W6+3370+9982.5-12.1W6-23.1W6+476.7-22.4W6-26.6=385.7W6+13802.6D=(385.7W6+13802.6)/502=0.768ws+27.510)蒸水量W1+W2+W3+W4+W5+W6=W0.876ws+6.66+0.926ws+1.1+0.955W6-19.7+0.991W

25、6-24+W6-35.3+W6=235.8W6=53.5kg/hW5=53.4-35.3=18.2kg/hW4=0.991X53.4-24=28.9kg/hW3=0.955X53.4-19.7=31.3kg/hW2=0.926X53.4+1.1=50.5kg/hW1=0.876X53.4+6.66=53.4kg/hD=0.768X53.4+27.5=68.5kg/h11)蒸汽單耗D/w=68.5/235.8=0.291kg.汽/kg.水13)熱負(fù)荷Q1=Dr=68.5X502=34378kcalQ2=W11=53.4X516=27554kcalQ3=w2r2=50.5x532=26866kca

26、lQ4=w3r3=31.3X544=17027kcalQ5=w4r4=28.9x553=15981kcalQ6=w5r5=18.1x561=10154kcal14)相對(duì)熱負(fù)荷g2=Q2/Q1=27554/34378=0.801g3=Q3/Qi=26866/34378=0.781g4=Q4/Qi=17027/34378=0.495g5=Q5/Qi=15981/34378=0.465g6=Q6/Q1=10154/34378=0.29515)驗(yàn)證有效溫差A(yù)t1=39/(1+g2XF1XK1/F2XK2+g3XF1乂K”F3XK3+gdxF1乂K”F4XK4+g5XF1xK1/F5XK5+g6XF1X

27、K1/F6XK6)=39/1+0.801X1955X1980/(1106X1580)+0.781X1955X1980/(1106X1580)+0.495X1955X1980/(1106X1400)+0.465X1955X1980/(1800X917)+0.295X1955X1980/(4000X1024)At1=5.5CAt2=5.5X0.801X1955X1980/(1106X1580)=9.8CAt3=5.5X0.781義1955X1980/(1106X1580)=9.5CAt4=5.5X0.495X1955X1980/(1106X1400)=6.7CAt5=5.5X0.465X1955X1980/(1800X917)=6.0CAt6=5.5X0.295X1955X1980/(4000X1024)=1.5C13、計(jì)算結(jié)果列表(第二次逼近值)IIIIIIIVVVII閃II閃III閃加熱蒸汽155135.5113.393.276.962.4溫度后效溫差5.59.89.56.8