计算原始资料:1.汽轮机型式及参数(1)机组型式:亚临界、一次中间再热、四缸四排汽、单轴、凝汽式汽轮机;(2)额定功率:pe=600MW(3)主蒸汽参数(主汽阀前):p0=16.7MPa,t0=537℃;(4)再热蒸汽参数(进汽阀前):热段:prh=3.23MPa,trh=537℃冷段:pˊrh=3.56MPa,tˊrh=315℃(5)汽轮机排汽压力pc=4.4/5.39MPa,排汽比焓:hc=2333.8KJ/Kg。2.回热加热系统参数:(1)机组各级回热抽汽参数见表1-1;表1-1回热加热系统原始汽水参数项目单位H1H2H3H4H5H6H7H8抽汽压力pˊjMpa5.893.591.60.740.3050.130.070.022抽汽比焓hjKJ/Kg31333016331731082913275026502491抽汽管道压损δpj%33333333水侧压力pwMpa20.120.1200.711.7241.7241.721.724加热器上端差δt℃-1.70002.82.82.82.8抽汽温度twj℃380.9316429323223.213788.52.8加热器下端差δt1℃5.55.55.55.55.55.55.5(2)最终给水温度:tfw=274.1℃;(3)给水泵出口压力:ppu=20.13MPa,给水泵效率:ηpu=0.83;(4)除氧器至给水泵高差:Hpu=21.6m(5)小汽机排汽压力:pe,xj=6.27MPa;小汽机排汽焓:hc,xj=2422.6KJ/Kg3.锅炉型式及参数(1)锅炉型式:英国三井2027-17.3/541/541;(2)额定蒸发量:Db=2027t/h;(3)额定过热蒸汽压力pb=20.13MPa;额定再热蒸汽压力pr=20.13MPa;(4)额定过热气温tb=541℃额定再热气温tr=541℃;(5)汽包压力pdu=20.13MPa;(6)锅炉热效率:ηb=92.5%。4.其他数据(1)汽轮机进汽节流损失δp1=4%,中压缸进汽节流损失δp2=2%(2)轴封加热器压力psg=98KPa,疏水比焓:hd,sg=415KJ/Kg(3)机组各门杆漏汽、轴封漏汽等小汽流量及参数见表1-2(4)锅炉暖风器耗汽、过热器减温水等全厂性汽水流量及参数见表1-3(5)汽轮机机械效率ηm=0.985,ηg=0.99(6)补充水温度tma=20℃(7)厂用电率:ε=0.07;(六)简化条件(1)忽略加热器和抽汽管道的散热损失;(2)忽略凝结水泵的介质比焓升。二、热系统计算(一)汽水平衡计算1.全厂补水率αma全厂汽水平衡如图所示,各汽水流量见表1-3.将进出系统的各流量用相对量α表示。由于计算前汽轮机进汽量D0为未知,故预选D0=1848840Kg/h进行计算。全厂工质渗漏系数αL=DL/D0=30000/1848840=0.01622锅炉排污系数αbl=Dbl/D0=10000/1848840=0.005408其余各量经计算为厂用汽系数αpl=0.01081减温水系数αsp=0.02974暖风器疏水系数αnf=0.01893由全厂物质平衡补水率αma=αpl+αbl+αL=0.01081+0.005408+0.01622=0.032442.给水系数αfw由图可知:1点物质平衡αb=α0+αL=1+0.01622=1.016222点物质平衡αfw=αb+αbl-αsp=1.01622+0.005408-0.02974=0.99193.各小汽流量系数αsg,k按预选的汽轮机进汽量D0和表1-2的原始数据,计算得到门杆漏汽、轴封漏汽等各小汽流量的流量系数,填于表1-2中。(二)汽轮机进汽参数计算1.主蒸汽参数由主汽门前压力p0=16.7MPa,温度t0=537℃,查水蒸气性质表,得主蒸汽比焓值:h0=3394.4KJ/Kg。主汽门后压力p‘0=(1-δp1)p0=(1-0.04)*16.7=16.032MPa由p‘0=16.032MPa,h’0=h0=3394.4KJ/Kg,查水蒸气性质表,得主汽门后气温t‘0=534.2℃2.再热蒸汽参数由中联门前压力prh=3.234MPa,温度trh=537℃查水蒸气性质表,得再热蒸汽比焓值:hrh=3536.6KJ/Kg中联门后压力p‘rh=(1-δp2)prh=(1-0.02)*3.234=3.169MPa由p‘rh=3.169MPa,h‘rh=hrh=3536.6KJ/Kg,查水蒸气性质表,得中联门后再热气温t‘rh=536.7℃(三)辅助计算1.轴封加热器计算以加权平均法计算轴封加热器的平均进汽比焓hsg。计算详见表1-42.均压箱计算以加权平均法计算均压箱内的平均蒸汽比焓hjy。计算详见表1-53.凝汽器平均压力计算由ps1=4.40KPa,查水蒸气性质表,得ts1=30.54℃由ps2=5.39KPa,查水蒸气性质表,得ts2=34.24℃凝汽器平均温度ts=0.5*(ts1+ts2)=32.44℃查水蒸气性质表,得凝汽器平均压力ps=4.9KPa(四)各加热器进、出水参数计算首先计算高压加热器H1加热器压力p1p1=(1-Δp1)p‘1=(1-0.03)*5.894=5.717MPa式中p‘1——第一抽汽口压力Δp1——抽汽管道相对压损;由p1=5.717MPa,查水蒸气性质表,得加热器饱和温度ts1=272.4℃H1出水温度tw,1:tw,1=ts1-δt=272.4-(-1.7)=274.1℃式中δt为加热器上端差。H1疏水温度td,1:td,1=t‘w,1+δt1=242.3+5.5=247.8℃式中δt1——加热器下端差,δt1=5.5℃t‘w,1——进水温度,℃已知加热器水侧压力pw=20.13MPa,由tw,1=274.1℃,查得H1出水比焓hw,1=1202.1KJ/Kg由t‘w,1=242.3℃,pw=20.13MPa,查得H1进水比焓h’w,1=1050.9KJ/Kg由td,1=247.8℃,p1=5.717MPa,查得H1疏水比焓hd,1=1075.1KJ/Kg至此,高压加热器H1进、出口汽水参数已经全部计算出。按同样计算,可依次计算其余加热器H2~H8的各进、出口汽水参数。将计算结果列于表1-61-6回热加热系统汽水参数计算项目单位H1H2H3H4H5H6H7H8SG*抽汽压力pˊjMpa5.893.591.60.740.3050.130.070.0222977抽汽比焓hjKJ/Kg31333016331731082913275026502491抽汽管道压损δpj%33333333加热器侧压力pjMpa5.723.491.60.720.2960.1260.070.021气侧压力下饱和温度ts℃272242200166132.6105.988.961.1水侧压力pwMpa20.120.1200.711.7241.7241.721.7241.72加热器上端差δt℃-1.70002.82.82.82.8出水温度tw,j℃274242200166129.8103.186.158.332.8出水比焓hw,jKJ/Kg12021051860699546.4433.3362246.7139进水温度tˊw,j℃242200166130103.186.158.332.7632.2进水比焓hˊw,jKJ/Kg1051868727546433.3361.8245138.8136加热器下端差δt1℃5.55.55.55.55.55.55.55.5疏水温度td,j℃248205175166108.691.663.838.2637.7疏水比焓hd,jKJ/Kg1075878726569455.5383.7268160.2415(五)高压加热器组抽汽系数计算1.由高压加热器H1热平衡计算α1高压加热器H的抽汽系数α1;α1=1d12,w,1fwh-h/h-h,)(hw=4.10759.31320.1/)9.10501.1202(9919.0=0.07293高压加热器的疏水系数αd,1αd,1=α1=0.072932.由高压加热器H2热平衡计算α2、αrh。高压加热器H2的抽汽系数α22,22,1,1,3,2,)(/hddddhwwfwhhhhh)(=5.8773016)5.8774.1075(07289.00.1/)1.8609.1050(9919.0=0.08171高压加热器H2的疏水系数αd,2αd,2=αd,1+α2=0.07271+0.08175=0.1546再热器流量系数αrhαrh=1-α1-α2-αsg,Β-αJ-αsg,L1-αsg,N1-αsg,L-αsg,M1-αsg,M-αsg,N=1-0.07298-0.08175-0.0001444-0.01636-0.001637-0.00004814-0.0003050-0.001859-0.00005463-0.0003456=0.82463.由高压加热器H3热平衡计算α3α3=3,33,,,3,2,2,3,fw)()(/ddksgksgdddhpuwhhhhhhhh)(=1.7407.3317)1.7406.3536(004008.0)1.7405.877(1546.00.1/)7.7241.860(9919.0=0.03848αd,3=αd,2+α3+αsg,k=0.1546+0.03848+0.004008=0.1971(六)除氧器抽汽系数计算除氧器出水流量αc,4αc,4=αfw+αsp=0.9919+0.02974=1.0216抽汽系数α4除氧器的物质平衡和热平衡见图,由于除氧器为汇集式加热器,进水流量αc,5为未知α4=[αc,4(hw,4-hw,5)/ηh-αd,3(hd,3-hw,3)-αsg,L1(hsg,L1-hw,5)-αsg,L(hsg,L-hw,5)-αnf(hnf-hw,5)]/(h4-hw,5)=[1.0216×(726.6-546.4)/1.0-0.1981×(740.1-546.4)-0.001637×(3328.1-546.4)-0.001859×(3016-546.4)-0.01893×(687-546.4)]/(3108.2-546.4)=0.04242(七)低压加热器组抽汽系数计算1.由低压加热器H5热平衡计算α5αc,5=αc,4-αd,3-α4-αsg,L1-αsg,L-αnf=1.0216-0.1981-0.04242-0.001637-0.001859-0.01893=0.7597低压加热器H5抽汽系数α5α5=5,56,5,5,/)(dhwwchhhh=5.4559.29120.1/)3.4334.546(7488.0=0.03496低压加热器H5疏水系数αd,5αd,5=α5=0.034962.由低压加热器H6热平衡计算α6低压加热器H6抽汽系数α6α6=6,66,5,5,7,6,c,5)(/hddddhwwhhhhh)(=.73835.2749)7.3835.455(03446.00.1/)8.3613.433(7488.0=0.0219低压加热器H6疏水系数αd,6αd,6=α6+αd,5=0.0219+0.03496=0.05686.由低压加热器H7热平衡计算α7α7=7,77,6,6,8,7,c,5)(/hddddhwwhhhhh)(=0.2675.2649)0.2677.383(05604.00.1/)4.2458.361(7488.0=0.03396低压加热器H7疏水系数αd,7αd,7=α7+αd,6=0.03396+0.05604=0.0908254.由低压加热器H8热平衡计算α8α8=8,88,7,7,sg,8,c,5)(/hddddhwwhhhhh)(=.2160.12491).2160267(08988.00.1/)2.7138.4245(7488.0