原則性熱力系統(tǒng)的計(jì)算

一、原則性熱力系統(tǒng)擬定及數(shù)據(jù)整理1、設(shè)計(jì)題目本次工程選擇的主機(jī)是上海汽輪機(jī)廠生產(chǎn)的引進(jìn)優(yōu)化型亞臨界300MW機(jī)組，該300MW汽輪機(jī)為上海汽輪機(jī)廠引進(jìn)美國(guó)西屋公司的技術(shù)制造的亞臨界、中間再熱、雙缸雙排汽、高中壓合缸、單軸、反動(dòng)、凝汽式汽輪機(jī)。型號(hào)：N300MW-16.7/538/538-1型；額定功率：300MW轉(zhuǎn)速：3000r/min；給水回?zé)幔喊硕尾徽{(diào)整抽汽（3個(gè)高壓加熱器+1個(gè)除氧器+4個(gè)低壓加熱器），其中高壓缸2段，中壓缸2段，低壓缸4段；額定背壓：0.0049MPa；額定冷卻水溫度：20°C；2、額定工況（TRL）下的熱力參數(shù)1）額定功率：300MW，外供熱量見任務(wù)書2）新蒸汽：（高壓主汽閥前）主汽壓力p0=16.7MPa；主汽溫t0=538C；再熱蒸汽：（中壓聯(lián)合汽閥前）pzr=3.41MPa；再熱汽溫tzr=538C3）排汽壓力pn=11.8kPa；排汽焓hn=2427.6kJ/kg4）系統(tǒng)補(bǔ)水率3%5）各級(jí)抽汽參數(shù)：見下表1）軸封各段漏氣份額及:序號(hào)來(lái)源符號(hào)流量份額焓值匯入點(diǎn)1門桿一段漏氣A0.4080.0004203397.2H12高中壓間隙漏氣E0.37640.0003883323.1H13高壓前軸封一段漏氣L10.8670.0111903034.9除氧器H44高壓前軸封二段漏氣N0.7530.0007753034.9除氧器H45高壓前軸封三段漏氣M0.1090.0001123034.9除氧器H46再熱閥桿漏氣K3.9170.0040343537.4H37中壓后軸封二段漏氣R0.1060.0001093109.1sg8中壓后軸封一段漏氣P0.7290.0007513109.1sg9低壓軸封二段漏氣T0.4840.0004982716.2sg10門桿二段漏氣B0.1250.0001293397.2sg11高壓缸流入中壓缸壓漏氣F——G14.2220.0146453323.1溢流至中壓缸2）整理數(shù)據(jù):300MW-16.7/0.8/538/538型雙缸雙排汽機(jī)組回?zé)嵯到y(tǒng)計(jì)算點(diǎn)參數(shù)項(xiàng)目單位H1H2H3H4H5H6H7H8SGC數(shù)據(jù)來(lái)源抽汽壓力pjMpa6.283.791.720.8250.3480.1370.07380.02220.0118已知抽汽壓損^pj%33355555已知加熱器汽側(cè)壓力'pjMpa6.0923.6761.660.78380.33060.13020.070110.2109計(jì)算抽汽焓值hjkJ/kg313030283330312529282755265824952427.6查水蒸汽表pj下飽和水溫tdj笆276.6245.4203.4169.6136.9107.29061.2349.08查水蒸汽表pj下飽和水的焓'hikJ/kg1218.51063.2867.76717.48575.9449.4376.92256.29205.49查水蒸汽表加熱器傳熱端差。j笆-1.70002.82.82.82.82.8已知加熱器出口水溫tj笆278.3245.4203.4169.6134.1104.487.258.4358.43tdj-9j加熱器水側(cè)壓力pwMpa20.8820.8820.880.78381.81.81.81.81已知加熱器出口水焓hwjkJ/kg1222.181065.03875.76717.48565.1438.9366.53246.09246.09由pw、tj查水蒸汽表疏水端差J笆5.65.65.65.65.65.65.6疏水出口水溫笆251209178.711092.858.99tj+1+疏水端差疏水冷卻出口水焓hwjdkJ/kg1090.1893.73742.46461.81388.75246.97查水蒸汽表3536t3LI5h3B3.ltOJ4￡pJD2S11292Sh建.11Q.lS'p，0.1302-p。一泓L39PtlC,7p2-^h16"p2-3536t3LI5h3B3.ltOJ4￡pJD2S11292Sh建.11Q.lS'p，0.1302-p。一泓L39PtlC,7p2-^h16"p2-5?hkJ「臉?K)333Dh二、全廠熱力系統(tǒng)工質(zhì)平衡汽輪機(jī)總耗汽量鍋爐蒸發(fā)量D'=D0Db=D’+Dl=D0+0.03DbDb=1.0309D0鍋爐給水量Dfw=Db+Dbl=1.0309D0+0.03Db=1.061827D01）擴(kuò)容排污w排污量Dbl=3%Db排污擴(kuò)容器和排污水冷卻器的熱效率nf,nf為98%。取汽包壓力p=1.12p0,p0=18.704MPa,p=18.704MPa下飽和水的焓值hbl,查水蒸氣表得：hbl=1763.232kJ/kg。p擴(kuò)=p,4（1+3%）=0.80731MPa。p擴(kuò)下飽和水和飽和蒸汽的焓hf'、hf"。查水蒸氣表得hf'=722.84kJ/Kg,hf"=2769.23kJ/Kg由擴(kuò)容排污器物質(zhì)平衡得：Dbl=Df+D'bl（2」）由擴(kuò)容排污器熱平衡得：DblhblL=Dfhf''+Dbl'hf'（2-2）由公式（2-1）和（2-2）得Df=0.01519D0,Dbl=0.015737D0Dfw=Db+Dbl=1.0309D0+0.03Db=1.061827D0故化補(bǔ)水量Dma=（Dl+D'）+100000=0.046664D0+100000擴(kuò)容排污冷卻器取化補(bǔ)水溫度為15°C，則化補(bǔ)水焓值hwma=4.1818X15=62.727kJ/kg環(huán)境參數(shù)為90kPa,thj=15C，排入地溝的水溫度為40C。。,由90kPa,40C查水蒸氣表得hwcbl=167.58kJ/kgw,。由擴(kuò)容排污冷卻器熱平衡得：Dbl'（h'-hwc,bl）%=Dma1（hwc,ma-hw,ma）將數(shù)據(jù)代入公式（3-5）得：hwcma=246.238kJ/kg擴(kuò)容匯總€(gè),'9Dbl=0.030927D0,hbl=1763.232kJ/kgp擴(kuò)=0.80731MPa,hf'=722.84kJ/kg,hf"=2769.23kJ/kgDf=0.01519D0,Dbl'=0.015737D0Dma1=0.046664D0,hwma=62.727kJ/kg,hwcma=246.238kJ/kghwcbl=167.58kJ/kg3.2原則性熱力系統(tǒng)計(jì)算3.2.1各部分汽水流量計(jì)算1）1號(hào)高壓加熱器1#高壓加熱器熱平衡圖如圖3-3所示圖3-3H1熱平衡圖由H1熱平衡計(jì)算1號(hào)加熱器抽汽量[D(h-hJ+D(h-hdJ+D(h-hdJ]n=D(h-hJ(2-3)Ji'i1*/T/AVAi*/T/l_Vl_i*/T/J/Vi*/Tii/)/11W1AAW1EEW1hfwW1w2由公式(2-3)得:D=[D(h-h)/n-D(h-hd)-D(h-hd)]/(h-hd)1fwW1W2〃LhAAw1，EEw11w17_1.061827%(1222.18-1065.03)-0.00420。0(3397.2-1090.1)-0.000388。0(3323.1-1090.1)

3130-1090.1=0.081728D0由H1物質(zhì)平衡得H1疏水流量：Dd1=D1=0.081728D02號(hào)高壓加熱器2#高壓加熱器熱平衡圖如圖3-4所示圖3-4H2熱平衡圖由H2熱平衡計(jì)算2號(hào)加熱器抽汽量[D2(h2-hW2d)+Dd1(hw1d-hW2d)]nh=Dfw(hw2-hw3)(2一4)由公式(2-4)得：D2=[Dfw(hw2-hw3)/nh-Dd1(hw1d-hW2d)]/(h2-hw2d)1.061827D0(1065.03-875.76)-0.081728I)0(1090.1-893.72)3028-893.72=0.087595D0由物質(zhì)平衡得H2疏水流量：Dd2=Dd1+Dd2=0.169323D0再熱蒸汽量Drh，由高壓缸物質(zhì)平衡得Drh=D0-D1-D2-DB-DA-DLMN-DF-G=0-803405D03號(hào)高壓加熱器3#高壓加熱器熱平衡圖如圖3-5所示。圖3-5H3熱平衡圖先計(jì)算給水泵焓升△hpuw。設(shè)除氧器的水位高度為20米，則給水泵的進(jìn)口壓力為pin=20X0.098+0.7838=0.9798MPa,取給水的平均比體積為vav=0.0011m3/kg、給水泵效率npu=0.83，給水泵出口壓力為pout=p0X1.25=20.88MPa,貝^Ahpuw=1000vavx(pout-p.n)/0.83=26.374kJ/kg由H3熱平衡得[D3(h3-hw3d)+Dd2(hw2d-hw3d)+Dk(hk-hw3d)]nh=Dfw[hw3-(hw4+火w)](2-5)由公式(2-5)得：D3={Dfw[hw3-(hw4+Mpuw)]/Hh-Dd2(hw1d-hw2d)-Dk(hk-hw3d)}/(h3-hw3d)_1.061827Do(867.76-717.48-26.374)-0.169323Do(893.72-742.46)-0.004034Do(3537.4-742.46)3330-742.46_0.040338D0由物質(zhì)平衡得H3疏水流量：Dd3_Dd2+D3_0.209660D04）四號(hào)加熱器（除氧器）四號(hào)加熱器熱平衡圖如圖3-6所示。第四段抽汽D4包括除氧器加熱蒸汽D'4、汽動(dòng)給水泵用汽D|t和外供熱用汽D供三部分組成。Dh圖3-6H4熱平衡圖TOC\o"1-5"\h\zDfw'_Dfw(2-6)Dfw'_D4'+Df+Dd3+Dc4+D|(2-7)由公式(2-6)和(2-7)得：D4'_Dfw'-Df-Dd3-Dc4-D|(2-8)由除氧器熱平衡得(以hw5為基準(zhǔn))'[D4'(h4-hw5)+Dd3(hw3d-hw5)+Df(hf"-hw5沖佝一喝]^h_、嘰4-hw5)](2一9)由公式(2-9)得：D4_[Dfw(hw4-hw5-Dd3(hw3d-hw5)-Df(hf"-hw5)-D|(h|-hw5)]/(h4-hw5)

_1.061827D0(717.48-565.1)-0.20966D0(742.46-565.1)-0.01519D0(2769.23-565.1)-0.01119(3034.9-565.1)3125-565.1=0.024587DO除氧器進(jìn)水量:Dc4=Dfw'-D4'-Dd3-Df=ON1239。。小汽機(jī)排汽壓力P|t=0.001Mpa+0.0118Mpa=0.0128Mpa,x=0.95,查h-s圖得：(2-10)h|t=2476kJ/kgDit(h4-hit虬火=Dfw'M(2-10)由公式(2-10)得:D|t=0.53049D0D4=D4'+Dit+D供=0.77636Do+1000005號(hào)低壓加熱器5#低壓加熱器熱平衡圖如圖3-7所示。H-vy：D-4I-H-vy：D-4I-圖3-7H5熱平衡圖(2-11)由H5熱平衡計(jì)算(2-11)D5(h5-hw5d)Hh=Dc4(hw5-hw6)公式(2-11)得：D5=Dc4(hw5-hw6)/認(rèn)-hw6d)0.812390D-(565.1-438.9)=2928-461.81=0.041992D°由H5物質(zhì)平衡得疏水量：Dd5=D5=0.041992D06號(hào)低壓加熱器6#低壓加熱器熱平衡圖如圖3-8所示。

圖3-8H6熱平衡圖由H6熱平衡計(jì)算6號(hào)加熱器抽汽量[D6(h6-hw6d)+Dd5(hw5d-hw6d)]氣=Dc4[hw6-hw7)](2-12)由公式(2-12)得：D6=[Dc4(hw6-W"Dd5(hw5d-hw6d)]/(h6-hw6d)0.81239。0(438.9-366.53)-0.41992。0(461.81-388.75)2755-388.75=0.023801DO由H6物質(zhì)平衡點(diǎn)疏水量：Dd6=Dd5+Dd6=O.O65792D07號(hào)低壓加熱器(H7)，熱平衡圖如圖3-9所示。11-yS11-yS圖3-9H7熱平衡圖由H7熱平衡計(jì)算7號(hào)低壓加熱器抽汽量[D7(h7-hw7d)+Dd6(hw6d-hw7d)]h=Dc4[hw7-hw8)](2-13)由公式(2-13)得：D7=[Dc4(hw7-hw8)/Hh-Dd6(hw6d-hw7d)]/(h7-hw7d)0.81239O0(366.53-246.09)-0.065792O0(388.75-246.97)

2658-246.97=0.037123D0由H7物質(zhì)平衡得疏水量：Dd7=Dd6+D7=0.102915D08號(hào)低壓加熱器和凝汽器熱井8號(hào)低壓加熱器和凝汽器熱井熱平衡圖如圖3-10所示。由H8和凝汽器熱井熱平衡計(jì)算8號(hào)低壓加熱器抽汽量圖3-10H8與熱井熱平衡圖[D(h—h')+D(hd—h')+D(hw-h')+D(h—h')+88cd77cma1cmacma2w,mac'DB(hB-hc')+DT(hT-hc')+DM(hM-hc')+DW(hW-hc')+DR(hR-hc')]nh=Dc4(hw8-hc')D8=0.010037D0+6235.53由H8物質(zhì)平衡得疏水量：Dd8=Dd7+D8=0.112952D0+6235.53由凝汽器熱井物質(zhì)平衡計(jì)算DcDc=Dc4-Dd8-Dma-Dlt-Ds=0.598238D0-106235.53由汽輪機(jī)物質(zhì)平衡校核S§Dc*=D0-Z8Dj-，Dsg=1-0.400997D0-0.018396D0-106235.53=0.581526D0-106235.53Dc*和Dc誤差很小，符合工程要求。3.2.2。汽輪機(jī)汽耗計(jì)算及功率校核計(jì)算汽輪機(jī)的內(nèi)功率Wi:W.=D0h0+Drhqrh-ED.hj-Dchc-Dsghsg(2-14)將數(shù)據(jù)代入公式(2-14)得：JJ''S§S§W.=1082.965D0-69929560.11由功率方程式計(jì)算D0W.=3600Pe/nm/ng=1113172542kg/h(2-15)由公式(2-14)和(2-15)得:D0=1092465kg/h=1092.465t/h求各級(jí)抽汽量及功率校核將D0數(shù)據(jù)代入各處汽水值，功率校核W.=Wc+EW.=1116464560kJ/h6Wi==|Wi*-Wi|/Wi*=0.295%3.2.3熱經(jīng)濟(jì)指標(biāo)計(jì)算1)機(jī)組熱耗、機(jī)組熱耗熱