300MW機(jī)組發(fā)電廠78號低加疏水泵熱經(jīng)濟(jì)對比

本文格式為Word版，下載可任意編輯——300MW機(jī)組發(fā)電廠78號低加疏水泵熱經(jīng)濟(jì)對比摘要

本論文主要針對300MW機(jī)組發(fā)電廠的原則性熱力系統(tǒng)，對回?zé)峒訜嵯到y(tǒng)中7號、8號加熱器分別設(shè)置疏水泵，通過計算分析兩種回?zé)嵯到y(tǒng)的熱經(jīng)濟(jì)性。通過設(shè)計了解、學(xué)習(xí)電廠熱力系統(tǒng)規(guī)劃、設(shè)計的一般途徑和方案論證、優(yōu)選的原則；學(xué)會全面性熱力系統(tǒng)計算和發(fā)電廠主要熱經(jīng)濟(jì)指標(biāo)計算的內(nèi)容、方法。本次我們要解決的問題主要是對疏水泵的選型以及加在不同位置的熱經(jīng)濟(jì)性和技術(shù)要求的對比，選出何時的優(yōu)化原則。這次設(shè)計能使我全面的了解熱力發(fā)電廠的系統(tǒng)圖，熟悉疏水泵在電廠中的應(yīng)用以及電廠的優(yōu)化的經(jīng)濟(jì)性，了解發(fā)電廠的熱經(jīng)濟(jì)性指標(biāo)，使發(fā)電廠高效、安全的運行。

h，kj/kg2′3540537t3.6633950′2″1.68p435t333330.82p337431320.327p230529260.13567143t27630.074p26630.026p282780.00542349C16.7p0537t5.93p385t131403.66p321t23035

熱力過程線

4

各計算點的汽水參數(shù)單項目名稱汽水位參數(shù)H4H5H60.135143276360.127106.388446.0453H70.07491.326636H80.026X=0.96C0.0054X=0.91回抽汽壓熱力Pj抽抽汽溫汽度tj抽汽焓hj抽汽壓損△pj加熱器壓力MPa5.933.661.680.820.327℃384.8321.1435336.8230kJ/31403035333331322926㎏%66660.774169.024714.99160.306134.196564.324025272349634.194143.22MPa5.573.441.645241.553207.080.06960.02489.79563.991376.0763267.8543加熱器℃270.內(nèi)飽和618水溫tsj加熱器內(nèi)飽和水焓被加熱器加的上端熱差θt水加熱器的下端差θtw加熱器出口水溫twj加熱器出口水焓hwj加熱器進(jìn)口水溫twj＋1加熱器進(jìn)口水焓hwi＋1疏加熱器水疏水溫度kJ/11871044864.㎏.887.632662℃000℃1.6700000.220.220.22℃270.618241.553207.08169.024714.991134.196564.324106.388103.38886.79560.991kJ/11871044864.㎏.887.632662℃241.553207.08174.91433.04363.46255.3589.79563.99134.194kJ/1044864.㎏.632662740.791446.045376.076267.854149.50℃243.223207.08864.662174.91752.575

103.608434.4590.015364.21134.414加熱器kJ/1052疏水焓㎏.82376.94268.81114.161.2．2鍋爐連續(xù)排污利用系數(shù)的計算

連續(xù)排污利用系統(tǒng)的汽水參數(shù)列于下表項目鍋爐排污水?dāng)U容蒸汽擴(kuò)容器排污水鍋爐的蒸發(fā)量

Db?D0?D1?D0?0.01Db?1.0101D0，即?b=1.0101

汽水參數(shù)P（MPa）20.40.900.90T（℃）367.44175175H（kJ/㎏）1849.92773742.6汽水損失

D1?0.1Db?0.0101D0即?s=0.0101

鍋爐排污量

Db1?0.01Db?0.0101D0即?b1=0.0101

鍋爐給水量

Dfw?Db?Db1??0.0101?1.0101?D0?1.0202D0,即?fw=1.0202小汽輪機(jī)的用汽量

Dtd=34.988kJ/㎏Db=1025kJ/㎏D0=1014.75kJ/㎏Dtd=34.988/1014.75Do=0.03448即?t=0.03448擴(kuò)容器產(chǎn)生的擴(kuò)容蒸汽份額?f擴(kuò)容器的物質(zhì)平衡式?b1??f??b1

'擴(kuò)容器的熱平衡式?b1hb?f??fh''f??b'1h'fkJ/㎏1'兩式聯(lián)立求解的?f?hb'1?f?h'fh''f?h'f?b1

=0.0101×(1849.9×0.98-742.6)÷(2773-742.6)=0.00532

'未擴(kuò)容的排污水份額?b1??b1??f=0.00478

化學(xué)補充水份額?ma

?ma??1??b'1=0.0101+0.00478=0.01488

6

1.3、各級加熱器的計算1.3.1、H1的計算

熱平衡式ɑ1（h1-hs1)?r=ɑfw(hw1-hw2)

α(h-h)ɑ1=fww1w2

?h1-hs1?ηr?fw1hw?1h1hw2=

1.0202??1187.887?1044.632?0.99??3140?1052.82?hs1=0.070731.3.2、H2的計算

熱平衡式

{?sg1（hsg1-hs2）+?2（h2-hs2）+?1（hs1-hs2）}?r=?fw(hw2-hw3)

?2??2??fw(hw2-hw3)-??h-h?h-h?????sg1?sg1s2??s1s2?1?r?r?h2-hs2?

?2h2?sg1hsg11.0202??1044.632?864.662????0.004429??3394.45?887.70??0.07073??1052.82?887.70????0.99?3035?887.70??0.99=0.07576hw2hw3?1hs1???????h12sg1s21.3.3、H3的計算{ɑsg2（hsg2-hs3）+ɑ3（h3-hs3）+（ɑ1+ɑ2+ɑsg1）（hs2-hs3）}?r=ɑfw（hw3-hw4）

?3??3??fw?hw3-hw4?-??sg2?hsg2-hs3???1??2??sg1?hs2-hs3???r????h3-hs3??r?3333?752.57??0.99?

1.0202??864.662?714.991????0.004053??3535.66?752.57???0.07576?0.07073?0.004429??887.70?752.57????0.99?3=0.03720

1.3.4、H4的計算

物質(zhì)平衡式

hw3?3h3?h?sg2hsg2hw4????12??sg1?hs2????????123sg1??sg2?hs3?c4=?fw-?1-?2-?3-?4-?f

=1.0202-0.07073-0.07576-0.03720-0.0232-?4

?c4+?4=0.83119

熱平衡式

ɑ4h4ηc+（ɑ1+ɑ2+ɑ3+ɑsg1+ɑsg2）hs3+ɑc4hw5+ɑfhf+ɑsg3hsg3ηc=?fwhDH

7

?4×3132×0.985+0.985×0.013233×3028.44+?c4×564.324+0.00532×

2773+（0.07073+0.07576+0.03720+0.004299+0.004053）×752.57=1.0202×714.991

聯(lián)立兩式的?4=0.02441?c4=0.80678

?sg3hsg3?fhf?4h4????12??3??sg1??sg2?hs?c4hw51.3.5、H5的計算

?5（h5-hs5)?r=?c4(hw5-hw6)?5（2926-434.45）×0.99=0.80678×（564.324-446.045）?5=0.03869

?fw?5h5hw5?5hs5hw61.3.6、H6的計算

{?6（h6-hs6）+?5（hs5-hs6）}?r=

（?c4-?5-?6-?7）(hw6-hw7)+（?5-?6-?7）(hw6-hws7)

2267.5494?6-94.65?7=57.59495①

?6h6

1.3.7、H7的計算

hw6?5hs5hw7??5??6?hs6??5??6??7?hs7{?7（h7-hs7）+（?5+?6）（hs6-hs7）}?r=（?c4-?5-?6-?7）(hw7-hw8)2478.3581?7+215.1587?6=78.8964957②有①、②兩式的?6=0.02663?7=0.02952

hw7?7h7??c4??5??6??7?hw8??5??6??7?hs7??5??6?hs61.3.8、H8的計算

?8（h8-hs8)?r=（?c4-?5-?6-?7）(hw8-hsg)

8

（2527-142.48）×0.99×?8=0.71194×（255.35-hsg）③

hw8?8h8??c4??5??6??7?hw8?8hs8?hs1.3.9、軸封加熱器的計算

?sg4（hsg4-hs）=（?c4-?5-?6-?7）（hsg-hc+1.7）

hsg=149.5

解得③式的

hsg?sg4hsg4??c4??5??6??7?hc?8=0.03192

1.3．10、凝汽份額的計算

?sg4hssg4

α

=1-α1-α2-α3-α4-α5-α6-α7-α8-αt-α

=0.60751

c

sg1-

α

sg2-

α

sg3-

α

1.4、汽輪機(jī)汽耗量及各段抽汽量計算1.4.1、抽汽做功不足系數(shù)計算

根據(jù)已知參數(shù)，可以查水蒸汽表得到hrh=3035kJ/kg，hrh=3540kJ/kg，所以qrh=3540-3035=505kJ/kg

h0-hc+qrh=（3395-2349+505）kJ/kg=1551kJ/kgY1=

in

outh1?hc?qrh=(3140-2349+505)/1551=0.8356

h0?hc?qrhh2?hc?qrh=(3035-2349+505)/1551=0.7679

h0?hc?qrhh3?hc=(3333-2349)/1551=0.6344

h0?hc?qrhY2=

Y3=

h4?hcY4=Yt==(3132-2349)/1551=0.5048

h0?hc?qrhY5=

h5?hc=(2926-2349)/1551=0.3720

h0?hc?qrhh6?hc=(2763-2349)/1551=0.2669

h0?hc?qrhY6=

9

Y7=

h7?hc=(2663-2349)/1551=0.2025

h0?hc?qrhh8?hc=(2527-2349)/1551=0.1148

h0?hc?qrhhsg1?hc?qrhh0?hc?qrhhsg2?hch0?hc?qrhhsg3?hch0?hc?qrhhsg4?hch0?hc?qrh=(3394.45-2349+505)/1551=0.9996

Y8=

Ysg1=

Ysg2==(3535.66-2349)/1551=0.7651

Ysg3==(3028.44-2349)/1551=0.4381

Ysg4==(2716-2349)/1551=0.2366

各抽汽份額αj及其做功不足系數(shù)Yj的乘積αjYj見表2

1.4.2、汽輪機(jī)的汽耗量及各段抽汽量的計算

機(jī)組無回?zé)峒兡r時的汽耗量Dc0為

Dc0=3600Pe/(h0-hc+qrh)?mg=3600×3×100000/(1551×0.983)=708367.194kg/h機(jī)組有回?zé)釙r的汽耗量D0為

D0=Dc0/(1-??j)==708367.194/0.78458=902861.65kg/h表2αj、Yj和Dj

αjYjY1=0.8356Y2=0.7679Y3=0.6344Y4=0.5048Y5=0.3720Y6=0.2669Y7=0.2025Y8=0.1148Ysg1=0.9996Ysg2=0.7651Ysg3=0.4381Ysg4=0.2366Yt=0.5048αjYj0.059100.058180.023600.012320.014390.007110.005980.003660.004430.003100.005800.000340.01741Dj=αjD0/（kg/h）D1=63859.40D2=68400.80D3=33586.45D4=22038.85D5=34931.72D6=24043.21D7=26652.48D8=28819.34Dsg1=3998.77Dsg2=3659.30Dsg3=11947.57Dsg4=1291.09Dt=31130.67α1=0.07073α2=0.07576α3=0.03720α4=0.02441α5=0.03869α6=0.02663α7=0.02952α8=0.03192ααααsg1=sg2=sg3=sg4=0.0044290.0040530.0132330.001430αt=0.0344810

??j=0.39794??Y=0.21542jj?Dj=354359.65αc=1-??j=0.60206

項目全廠汽水損失鍋爐排污擴(kuò)容蒸汽濃縮排污水化學(xué)補充水小汽輪機(jī)用汽鍋爐蒸發(fā)量再熱蒸汽量鍋爐給水量1-??jYj=0.78458份額αxα1=0.0101αb1=DC=αcD0=548497.48流量Dx=α（kg/h）D1=9118.90Db1=9118.90Df=4803.22D'b1=4315.68Dma=13434.58Dt=31130.67Db=911980.55Drh=770601.45Dfw=921099.46x0D/0.0101αf=0.00532α'b1=0.00478αma=0.01488αt=0.03448αb=1.0101ααrh=fw=1-α1-α2=0.853511.02021.5、汽輪機(jī)的功率校核P1=

D（1h0?h1)?m?g3600D（2h0?h2)?m?g3600=4446.48kW

P2==6723.80kW

P3=

D（3h0?h3?qrh)?m?g3600D（4h0?h4?qrh)?m?g3600D（5h0?h5?qrh)?m?g3600D（6h0?h6?qrh)?m?g3600D（7h0?h7?qrh)?m?g3600D（8h0?h8?qrh)?m?g3600=5199.94kW

P4==4675.85kW

P5==9290.30kW

P6==7464.56kW

P7==9002.40kW

P8==10804.52kW

11

Pt=

D（th0?h4?qrh)?m?g3600D（ch0?hc?qrh)?m?g3600=6528.31kW

Pc==232293.71kW

汽輪機(jī)的總功率Pe=（Pc+Pt+計算誤差

Δ=

?P）=296429.87kW

jj=1?Pe?Pe，Pe?100%=1.19%

計算的電功率接近給定的電功率，說明計算結(jié)果確鑿。

1.6、熱經(jīng)濟(jì)指標(biāo)計算

1.6.1、汽輪機(jī)組熱耗量(含小汽輪機(jī))

Q0?D0(h0?hfw)?Drhqrh?Df(h''f?hfw)?Dma(hfw?hw)

=902861.65×(3395-1187.887)+770601.45×505+4803.22×(2773-1187.887)-13434.58×(1187.887-143.22)=2375450401kJ/h

1.6.2、汽輪機(jī)組熱耗率

q0=Q0/Pe=2375450401/300000=7918.17kJ/(kw·h)

1.6.3鍋爐熱負(fù)荷

Qb?Db(hb?hfw)?Drhqrh?Dbl(hbl?hfw)

×(3395-1187.887)+770601.45×505+9118.90×(1849.9-1187.887)

=2408034690kJ/h

1.6.4、各種效率

管道效率

ηp=Q0/Qb=2375450401/2408034690=98.6%

機(jī)組熱效率

ηe=3600/q0=3600/7918.17=45.47%

全廠熱效率

ηcp=ηbηpηe=0.91?0.986?0.4547=40.8%全廠熱耗率

qcp=3600/ηcp=3600/0.408=8823.53kJ/(kw·h)

發(fā)電標(biāo)準(zhǔn)煤耗率

bcp=0.123/ηcp=0.1243/0.406=0.30147kg/(kw·h)

12

2、疏水泵設(shè)置在8號低壓加熱器

在前面計算的基礎(chǔ)上，直接從5號低壓加熱器計算以后的步驟。

2.1、各級加熱器的計算2.1.1、H5的計算

?5（h5-hs5)?r=?c4(hw5-hw6)

?5（2926-434.45）×0.99=0.80678×（564.324-446.045）?5h5?5=0.038692.1.2、H6的計算

hw5?5hs5hw6{?6（h6-hs6）+?5（hs5-hs6）}?r=?c4(hw6-hw7)（2763-376.94）×0.99?6=0.80678×(433.04-363.46)-0.03869×(434.45-376.94)

?6=0.02282

?6h6hw7hw6?5hs52.1.3、H7的計算

??5??6?hs6{?7（h7-hs7）+（?5+?6）（hs6-hs7）}?r=

（?c4-?5-?6-?7-?8）(hw7-hw8)+（?5+?6+?7+a8）（hw7-hs8）

2257.3781?7-112.87a8=87.5114147④

?7h7hw7??c4??5??6??7??8?hw8??5??6??7??8?hs8??5??6?hs6??5??6??7?hs72.1.4、H8的計算

{?8（h8-hs8)+（?5+?6+?7）（hs7-hs8）}ηr=（?c4-?5-?6-?7）(hw8-hsg)

2616.025?8?380.416?7?182.613??hsg(0.745??7??8)

⑤

13

hw8?8h8??c4??5??6??7??8?hsg??5??6??7?hs7??c4??5??6??7??8?hsg2.1.5、軸封加熱器的計算?sg4（hsg4-hs）=（ɑc4-?5-?6-?7-?8）（hsg-hc+1.7）-hsg（0.74527-?7-?8）

=-111.2620541-144.92?7-144.92?8⑥由④⑤⑥解得?7=0.03968

hsg?sg4hsg4??c4??5??6??7??8?hc?8=0.01829

2.1.6、凝氣份額的計算

?sg4hsα

=1-α1-α2-α3-α4-α5-α6-α7-α8-αt-α

=0.61479

c

sg1-

α

sg2-

α

sg3-

α

sg4

2.2、汽輪機(jī)汽耗量及各段抽汽量計算2.2.1、抽汽做功不足系數(shù)計算

根據(jù)已知參數(shù)，可以查水蒸汽表得到hrh=3035kJ/kg，hrh=3540kJ/kg，所以qrh=3540-3035=505kJ/kg

h0-hc+qrh=（3395-2349+505）kJ/kg=1551kJ/kgY1=

in

outh1?hc?qrh=(3140-2349+505)/1551=0.8356

h0?hc?qrhh2?hc?qrh=(3035-2349+505)/1551=0.7679

h0?hc?qrhh3?hc=(3333-2349)/1551=0.6344

h0?hc?qrhY2=

Y3=

h4?hcY4=Yt==(3132-2349)/1551=0.5048

h0?hc?qrhY5=

h5?hc=(2926-2349)/1551=0.3720

h0?hc?qrhh6?hc=(2763-2349)/1551=0.2669

h0?hc?qrhY6=

14

Y7=

h7?hc=(2663-2349)/1551=0.2025

h0?hc?qrhh8?hc=(2527-2349)/1551=0.1148

h0?hc?qrhhsg1?hc?qrhh0?hc?qrhhsg2?hch0?hc?qrhhsg3?hch0?hc?qrhhsg4?hch0?hc?qrh=(3394.45-2349+505)/1551=0.9996

Y8=

Ysg1=

Ysg2==(3535.66-2349)/1551=0.7651

Ysg3==(3028.44-2349)/1551=0.4381

Ysg4==(2716-2349)/1551=0.2366

各抽汽份額αj及其做功不足系數(shù)Yj的乘積αjYj見表2

2.2.2、汽輪機(jī)的汽耗量及各段抽汽量的計算

機(jī)組無回?zé)峒兡r時的汽耗量Dc0為

Dc0=3600Pe/(h0-hc+qrh)?mg=3600×3×100000/(1551×0.983)=708367.194kg/h機(jī)組有回?zé)釙r的汽耗量D0為

D0=Dc0/(1-??j)==708367.194/0.7851=902263.65kg/h表2αj、Yj和Dj

αjYjY1=0.8356Y2=0.7679Y3=0.6344Y4=0.5048Y5=0.3720Y6=0.2669Y7=0.2025Y8=0.1148Ysg1=0.9996Ysg2=0.7651Ysg3=0.4381Ysg4=0.2366Yt=0.5048αjYj0.059100.058180.023600.012320.014390.006090.008040.002100.004430.003100.005800.000340.01741Dj=αjD0/（kg/h）D1=63817.11D2=68355.49D3=33564.21D4=22024.26D5=34908.58D6=20589.66D7=35801.82D8=16502.40Dsg1=3996.13Dsg2=3656.87Dsg3=11939.65Dsg4=1290.24Dt=31110.05α1=0.07073α2=0.07576α3=0.03720α4=0.02441α5=0.03869α6=0.02282α7=0.03968α8=0.01829ααααsg1=sg2=sg3=sg4=0.0044290.0040530.0132330.001430αt=0.0344815

??j=0.38521??Y=0.2149jj?Dj=347556.47αc=1-0.38521=0.61479

項目全廠汽水損失鍋爐排污擴(kuò)容蒸汽濃縮排污水化學(xué)補充水小汽輪機(jī)用汽鍋爐蒸發(fā)量再熱蒸汽量鍋爐給水量1-??Y=0.7851jjDC=αcD0=554702.67份額αxα1=0.0101αb1=流量Dx=αxD0/（kg/h）D1=9112.86Db1=9112.86Df=4800.04D'b1=4312.82Dma=13425.68Dt=31110.05Db=911376.51Dfw=920489.380.0101αf=0.00532α'b1=0.00478αma=0.01488αt=0.03448αb=1.0101ααrh=fw=1-α1-α2=0.85351Drh=770091.051.02022.3、汽輪機(jī)的功率校核P1=

D（1h0?h1)?m?g3600D（2h0?h2)?m?g3600=4443.53kW

P2==6719.34kW

P3=

D（3h0?h3?qrh)?m?g3600D（4h0?h4?qrh)?m?g3600D（5h0?h5?qrh)?m?g3600D（6h0?h6?qrh)?m?g3600D（7h0?h7?qrh)?m?g3600D（8h0?h8?qrh)?m?g3600=5196.49kW

P4==4672.76kW

P5==9284.15kW

P6==6392.35kW

P7==12092.77kW

P8==6186.84kW

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Pt=

D（th0?h4?qrh)?m?g3600D（ch0?hc?qrh)?m?g3600=6523.98kW

Pc==234921.67kW

汽輪機(jī)的總功率Pe=（Pc+Pt+計算誤差

Δ=

?P）=296433.88kW

jj=1?Pe?Pe，Pe?100%=1.19%

計算的電功率接近給定的電功率，說明計算結(jié)果確鑿。

2.4、熱經(jīng)濟(jì)指標(biāo)計算

2.4.1、汽輪機(jī)組熱耗量(含小汽輪機(jī))

Q0?D0(h0?hfw)?Drhqrh?Df(h''f?hfw)?Dma(hfw?hw)

=902263.65×(3395-1187.887)+770091.05×505+4800.04×(2773-1187.887)-13425.68×(1187.887-143.22)=2373877053kJ/h

2.4.2、汽輪機(jī)組熱耗率

q0=Q0/Pe=2373877053/300000=7912.92kJ/(kw·h)

2.4.3、鍋爐熱負(fù)荷

Qb?Db(hb?hfw)?Drhqrh?Dbl(hbl?hfw)

=911376051×(3395-1187.887)+770091.05×505+9112.86×(1849.9-1187.887)=2406439755kJ/h

2.4.4各種效率

管道效率

ηp=Q0/Qb=2373877053/2406439755=98.65%

機(jī)組熱效率

ηe=3600/q0=3600/7912.92=45.5%

全廠熱效率

ηcp=ηbηpηe=0.91?0.986?0.4547=40.9%

全廠熱耗率

qcp=3600/ηcp=3600/0.409=8801.96kJ/(kw·h)

發(fā)電標(biāo)準(zhǔn)煤耗率

bcp=0.123/ηcp=0.1243/0.409=0.3007kg/(kw·h)

17

3、經(jīng)濟(jì)性比較

熱電廠的疏水逐級自流的連接系統(tǒng)，該系統(tǒng)沒有疏水泵，系統(tǒng)簡單，運行可靠，不耗廠用電，運行維護(hù)便利，但由于疏水最終流入凝汽器，直接導(dǎo)致冷源損失增加，又由于存在排擠低壓抽汽現(xiàn)象，額外增加了冷源損失。因此，這種疏水方式經(jīng)濟(jì)性最差。采用疏水泵的連接系統(tǒng)，因其減少了相鄰高一級的抽汽量(用疏水泵將本級疏水送入加熱器出口凝結(jié)水管路中，提高了