汽机.docx
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汽机.docx
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汽机
3、.压力级第二级详细热力计算
(1)本级的比焓降Δht和本级滞止比焓降Δht(o)
由调节级的计算结果,已知本级的Po,ho,Po(o),δhco,
由压力级比焓降分配,已知本级的P2,dm,Gn
由P2和So查h2t'=3280.4227kJ/kg
本级比焓降Δht=ho-h2t'=3343.6331-3280.4227=63.2104(kJ/kg)
本级滞止比焓降Δht(o)=Δht+μo*δhco=63.2104+2.0982=65.3086(kJ/kg)
(2)选取平均反动度Ωm
选取Ωm=0.0640
(3)喷嘴的理想比焓降Δhn
Δhn=(1-Ωm)*Δht=(1-0.0640)*3280.4227=59.1649(kJ/kg)
(4)喷嘴的滞止理想比焓降Δhn(o)
Δhn(o)=Δhn+μo*δhco=59.1649+2.0982=61.2631(kJ/kg)
(5)喷嘴的出口汽流理想速度c1t
c1t=(2*Δhn(o))^0.5=(2*61.2631*1000)^0.5=350.04(m/s)
(6)喷嘴出口汽流实际速度c1
c1=φ*c1t=0.970*350.04=339.54(m/s)
(7)喷嘴损失δhn
δhn=(1-φ^2)*Δhn(o)=(1-0.970^2)*61.2631=3.4966(kJ/kg)
(8)圆周速度u
=π*dm*n/60=π*985.5/1000*3000.00/60=154.80(m/s)
(9)级的假想速度Ca
Ca=(2*Δht(o))^0.5=(2*65.3086*1000)^0.5=361.41(m/s)
(10)假想速比Xa
Xa=u/Ca=154.80/361.41=0.4283
(11)喷嘴等比熵出参数h1t
h1t=ho-Δhn=3343.6331-59.1649=3284.4682(kJ/kg)
(12)喷嘴前后压力比εn=P1/Po(o)=4.2373/5.1420=0.8241
(13)选取喷嘴型式和出汽角α1
选TC-1A喷嘴,出汽角α1=11°
(14)喷嘴出口面积An
An=G*V1t/μn/c1t=56.6802*0.0729/0.970/350.0400=0.0122(m^2)
(15)喷嘴高度ln
ln=An/(e*π*dm*sin(α1))
=0.0122/(1.0000*π*985.5/1000*sin11.00°)=20.7(mm)
(16)喷嘴出口实际比焓降h1
h1=h1t+δhn=3284.4682+3.4966=3287.9648(kJ/kg)
(17)动叶进口汽流角β1和相对速度w1
β1=arctg((c1*sin(α1)/(c1*cos(α1)-u))
=arctg(339.54*sin11.00°/(cos11.00°-154.80))=19.95°
w1=(c1^2+u^2-2*u*c1*cos(α1))^0.5
=(339.54^2+154.80^2-2*154.80*339.54*cos11.00°)^0.5=189.90(m/s)
(18)动叶理想比焓降Δhb
Δhb=Ωm*Δht=0.0640*63.2104=4.0455(kJ/kg)
(19)动叶滞止理想比焓降Δhb(o)
Δhb(o)=Δhb+δhw1=4.0455+18.0310=22.0765(kJ/kg)
(20)动叶出口理想汽流速度w2t
w2t=(2*Δhb(o))^0.5=(2*22.0765*1000)^0.5=210.13(m/s)
(21)动叶出口实际汽流速度w2
w2=ψ*w2t=0.931*210.13=195.63(m/s)
(22)动叶损失δhb
δhb=(1-ψ^2)*Δhb=(1-0.931^2)*4.0455=2.9415(kJ/kg)
(23)动叶后参数P2,V2
根据h2、P2查焓熵表得到
P2=4.1837Mpa,V2=0.0740m^3/kg
(24)动叶出口面积Ab
Ab=G*V2/w2=56.6802*0.0740/195.63=0.0214(m^2)
(25)动叶高度lb
lb=ln+Δ=20.7+2.50=23.2(mm)
(26)检验根部反动度Ωr
Ωr=1-(1-Ωm)*(db-lb)/db
=1-(1-0.0640)*(985.5-23.20)/985.5=0.0414在0.03-0.05范围内,符合要求。
(27)计算动叶出汽角β2
β2=arcsin(Ab/(e*π*dm*lb))
=arcsin(0.0214/(1.000*π*985.5/1000*23.2/1000)=17.33°
(28)根据β1和β2在动叶叶型表中选取动叶型号
选TP─1A型
(29)动叶出口绝对速度c2和方向角α2
c2=(w2^2+u^2-2*w2*u*cosβ2)^0.5
=(189.90^2+154.80^2-2*189.90*154.80*cos17.33°)^0.5=66.46(m/s)
α2=arctg=(w2*sin(β2)/(w2*cos(β2)-u))
=arctg(195.63*sin17.33°/(195.63*cos17.33°-154.80)=61.27°
(30)余速损失δhc2
=c2^2/2=66.46^2/2/1000=2.2085(kJ/kg)
(31)轮周有效比焓降Δhu'(无限长叶片)
Δhu'=Δht(o)-δhn-δhb-δhc2
=65.3086-3.4966-2.9415-2.2085=56.6620(kJ/kg)
(32)级消耗的理想能量Eo
Eo=Δht(o)-μ1*δhc2=65.3086-1.0000*2.21=63.1001(kJ/kg)
(33)轮周效率ηu'
ηu'=Δhu'/Eo=56.6620/63.1001=0.8980
(34)校核轮周效率
单位质量蒸汽对动叶所作的轮周功Wu
Wu=u*(c1*cos(α1)+c2*cos(α2))
=154.80*(339.54*cos11.00°+66.46*cos61.27°)/1000=56.5404(kJ/kg)
轮周效率ηu”=Wu/Eo=56.5404/63.1001=0.8960
Δηu=|ηu'-ηu”|/ηu'*100%=0.0022小于1%,满足要求。
(35)叶高损失δhl
δhl=a/l*Δhu'1.600/1.1*56.6620=56.6620(kJ/kg)
(36)轮周有效比焓降Δhu
Δhu=Δhu'-δhl=56.6620-4.3797=52.2823(kJ/kg)
(37)轮周效率ηu=Δhu/Eo=52.2823/63.1001=0.8286
(38)叶轮摩擦损失δhf
其中ΔPf=K1*(u/100)^3*dm^2/v,Δhf=ΔPf/G
ΔPf=1.0700*(154.8000/100)^3*(985.5000/1000)^2/0.0740=52.0929(kJ/kg)
δhf=52.0929/56.6802=0.9191(kJ/kg)
(39)漏气损失δhδ
隔板汽封齿的平均直径dp=590.0mm隔板汽封间隙δp=0.5mm
汽封齿数Zp=10
则有隔板漏气损失δhp=Ap/An*(Zp^0.5)*Δhi'
这里Ap=π*dp*δp
Δhi'=Δht(o)-δhn-δhb-δhl-δhc2
=65.3086-3.4966-2.9415-4.3797-2.2085=52.2823(kJ/kg)
Ap=π*590.0/1000*0.5/1000=0.0009(m^2)
δhp=0.0009/0.0122/(10)^0.5*56.6620=1.2197(kJ/kg)
选取:
叶顶轴向间隙δz=1.5mm围带边厚度Δs=0.3mm
δz(平均)=1.5/23.2=0.0647(kJ/kg)
由Ωm与db/lb查取Ψt,由δz/Δs查取μ1,由δz和u/Ca查取μ2,
动叶顶部漏气损失
δht=μ1*δz(平均)*Ψt/(μ2*sin(α1))*Δhi'
=0.300*0.0647*0.216/(0.956*sin11.00)*56.6620=1.2016(kJ/kg)
级的总漏气损失δhδ=δhp+δht=1.2197+1.2016=2.4213(kJ/kg)
(40)级内各项损失之和Σδh
Σδh=δhl+δhf+δhδ=4.3797+0.9191+2.4213=7.7201(kJ/kg)
(41)级的有效比焓降Δhi
Δhi=Δhu'-Σδh=56.6620-7.7201=48.9419(kJ/kg)
(42)级效率ηi
ηi=Δhi/Eo=48.9419/63.1001=0.7756
(43)级内功率Pi(s)
Pi(s)=G*Δhi=56.6802*48.9419=2774.0367(kW)
(43)级后参数
h3=h2+Σδh+(1-μ1)*δhc2=3286.8608+7.7201+(1-1.00)*2.2085=3294.5809(kJ/kg)
h3(o)=h2+μ1*δhc2=3294.5809+1.00*2.2085=3296.7894(kJ/kg)
由h3(o)和S3查P3(o)=4.2090Mpa
4..压力级第三级详细热力计算
(1)本级的比焓降Δht和本级滞止比焓降Δht(o)
由调节级的计算结果,已知本级的Po,ho,Po(o),δhco,
由压力级比焓降分配,已知本级的P2,dm,Gn
由P2和So查h2t'=3231.3750kJ/kg
本级比焓降Δht=ho-h2t'=3294.5809-3231.3750=63.2059(kJ/kg)
本级滞止比焓降Δht(o)=Δht+μo*δhco=63.2059+2.2085=65.4144(kJ/kg)
(2)选取平均反动度Ωm
选取Ωm=0.0640
(3)喷嘴的理想比焓降Δhn
Δhn=(1-Ωm)*Δht=(1-0.0640)*3231.3750=59.1607(kJ/kg)
(4)喷嘴的滞止理想比焓降Δhn(o)
Δhn(o)=Δhn+μo*δhco=59.1607+2.2085=61.3692(kJ/kg)
(5)喷嘴的出口汽流理想速度c1t
c1t=(2*Δhn(o))^0.5=(2*61.3692*1000)^0.5=350.34(m/s)
(6)喷嘴出口汽流实际速度c1
c1=φ*c1t=0.970*350.34=339.83(m/s)
(7)喷嘴损失δhn
δhn=(1-φ^2)*Δhn(o)=(1-0.970^2)*61.3692=3.4964(kJ/kg)
(8)圆周速度u
=π*dm*n/60=π*990.0/1000*3000.00/60=155.51(m/s)
(9)级的假想速度Ca
Ca=(2*Δht(o))^0.5=(2*65.4144*1000)^0.5=361.70(m/s)
(10)假想速比Xa
Xa=u/Ca=155.51/361.70=0.4299
(11)喷嘴等比熵出参数h1t
h1t=ho-Δhn=3294.5809-59.1607=3235.4202(kJ/kg)
(12)喷嘴前后压力比εn=P1/Po(o)=3.4470/4.2090=0.8190
(13)选取喷嘴型式和出汽角α1
选TC-1A喷嘴,出汽角α1=11°
(14)喷嘴出口面积An
An=G*V1t/μn/c1t=56.6802*0.0865/0.970/350.3400=0.0144(m^2)
(15)喷嘴高度ln
ln=An/(e*π*dm*sin(α1))
=0.0144/(1.0000*π*990.0/1000*sin11.00°)=24.3(mm)
(16)喷嘴出口实际比焓降h1
h1=h1t+δhn=3235.4202+3.4964=3238.9166(kJ/kg)
(17)动叶进口汽流角β1和相对速度w1
β1=arctg((c1*sin(α1)/(c1*cos(α1)-u))
=arctg(339.83*sin11.00°/(cos11.00°-155.51))=20.01°
w1=(c1^2+u^2-2*u*c1*cos(α1))^0.5
=(339.83^2+155.51^2-2*155.51*339.83*cos11.00°)^0.5=189.51(m/s)
(18)动叶理想比焓降Δhb
Δhb=Ωm*Δht=0.0640*63.2059=4.0452(kJ/kg)
(19)动叶滞止理想比焓降Δhb(o)
Δhb(o)=Δhb+δhw1=4.0452+17.9570=22.0022(kJ/kg)
(20)动叶出口理想汽流速度w2t
w2t=(2*Δhb(o))^0.5=(2*22.0022*1000)^0.5=209.77(m/s)
(21)动叶出口实际汽流速度w2
w2=ψ*w2t=0.932*209.77=195.51(m/s)
(22)动叶损失δhb
δhb=(1-ψ^2)*Δhb=(1-0.932^2)*4.0452=2.8906(kJ/kg)
(23)动叶后参数P2,V2
根据h2、P2查焓熵表得到
P2=3.4003Mpa,V2=0.0878m^3/kg
(24)动叶出口面积Ab
Ab=G*V2/w2=56.6802*0.0878/195.51=0.0255(m^2)
(25)动叶高度lb
lb=ln+Δ=24.3+2.50=26.8(mm)
(26)检验根部反动度Ωr
Ωr=1-(1-Ωm)*(db-lb)/db
=1-(1-0.0640)*(990.0-26.80)/990.0=0.0380在0.03-0.05范围内,符合要求。
(27)计算动叶出汽角β2
β2=arcsin(Ab/(e*π*dm*lb))
=arcsin(0.0255/(1.000*π*990.0/1000*26.8/1000)=17.81°
(28)根据β1和β2在动叶叶型表中选取动叶型号
选TP─1A型
(29)动叶出口绝对速度c2和方向角α2
c2=(w2^2+u^2-2*w2*u*cosβ2)^0.5
=(189.51^2+155.51^2-2*189.51*155.51*cos17.81°)^0.5=67.19(m/s)
α2=arctg=(w2*sin(β2)/(w2*cos(β2)-u))
=arctg(195.51*sin17.81°/(195.51*cos17.81°-155.51)=62.88°
(30)余速损失δhc2
=c2^2/2=67.19^2/2/1000=2.2572(kJ/kg)
(31)轮周有效比焓降Δhu'(无限长叶片)
Δhu'=Δht(o)-δhn-δhb-δhc2
=65.4144-3.4964-2.8906-2.2572=56.7702(kJ/kg)
(32)级消耗的理想能量Eo
Eo=Δht(o)-μ1*δhc2=65.4144-1.0000*2.26=63.1572(kJ/kg)
(33)轮周效率ηu'
ηu'=Δhu'/Eo=56.7702/63.1572=0.8989
(34)校核轮周效率
单位质量蒸汽对动叶所作的轮周功Wu
Wu=u*(c1*cos(α1)+c2*cos(α2))
=155.51*(339.83*cos11.00°+67.19*cos62.88°)/1000=56.6391(kJ/kg)
轮周效率ηu”=Wu/Eo=56.6391/63.1572=0.8968
Δηu=|ηu'-ηu”|/ηu'*100%=0.0023小于1%,满足要求。
(35)叶高损失δhl
δhl=a/l*Δhu'1.600/1.1*56.7702=56.7702(kJ/kg)
(36)轮周有效比焓降Δhu
Δhu=Δhu'-δhl=56.7702-3.7380=53.0322(kJ/kg)
(37)轮周效率ηu=Δhu/Eo=53.0322/63.1572=0.8397
(38)叶轮摩擦损失δhf
其中ΔPf=K1*(u/100)^3*dm^2/v,Δhf=ΔPf/G
ΔPf=1.0700*(155.5100/100)^3*(990.0000/1000)^2/0.0878=44.9195(kJ/kg)
δhf=44.9195/56.6802=0.7925(kJ/kg)
(39)漏气损失δhδ
隔板汽封齿的平均直径dp=590.0mm隔板汽封间隙δp=0.5mm
汽封齿数Zp=10
则有隔板漏气损失δhp=Ap/An*(Zp^0.5)*Δhi'
这里Ap=π*dp*δp
Δhi'=Δht(o)-δhn-δhb-δhl-δhc2
=65.4144-3.4964-2.8906-3.7380-2.2572=53.0322(kJ/kg)
Ap=π*590.0/1000*0.5/1000=0.0009(m^2)
δhp=0.0009/0.0144/(10)^0.5*56.7702=1.0481(kJ/kg)
选取:
叶顶轴向间隙δz=1.5mm围带边厚度Δs=0.3mm
δz(平均)=1.5/26.8=0.0560(kJ/kg)
由Ωm与db/lb查取Ψt,由δz/Δs查取μ1,由δz和u/Ca查取μ2,
动叶顶部漏气损失
δht=μ1*δz(平均)*Ψt/(μ2*sin(α1))*Δhi'
=0.300*0.0560*0.216/(0.956*sin11.00)*56.7702=1.0550(kJ/kg)
级的总漏气损失δhδ=δhp+δht=1.0481+1.0550=2.1031(kJ/kg)
(40)级内各项损失之和Σδh
Σδh=δhl+δhf+δhδ=3.7380+0.7925+2.1031=6.6336(kJ/kg)
(41)级的有效比焓降Δhi
Δhi=Δhu'-Σδh=56.7702-6.6336=50.1366(kJ/kg)
(42)级效率ηi
ηi=Δhi/Eo=50.1366/63.1572=0.7938
(43)级内功率Pi(s)
Pi(s)=G*Δhi=56.6802*50.1366=2841.7525(kW)
(43)级后参数
h3=h2+Σδh+(1-μ1)*δhc2=3237.7620+6.6336+(1-1.00)*2.2572=3244.3956(kJ/kg)
h3(o)=h2+μ1*δhc2=3244.3956+1.00*2.2572=3246.6528(kJ/kg)
由h3(o)和S3查P3(o)=3.4256Mpa
5、.压力级第四级详细热力计算
(1)本级的比焓降Δht和本级滞止比焓降Δht(o)
由调节级的计算结果,已知本级的Po,ho,Po(o),δhco,
由压力级比焓降分配,已知本级的P2,dm,Gn
由P2和So查h2t'=3179.8018kJ/kg
本级比焓降Δht=ho-h2t'=3244.3956-3179.8018=64.5938(kJ/kg)
本级滞止比焓降Δht(o)=Δht+μo*δhco=64.5938+2.2572=66.8510(kJ/kg)
(2)选取平均反动度Ωm
选取Ωm=0.0640
(3)喷嘴的理想比焓降Δhn
Δhn=(1-Ωm)*Δht=(1-0.0640)*3179.8018=60.4598(kJ/kg)
(4)喷嘴的滞止理想比焓降Δhn(o)
Δhn(o)=Δhn+μo*δhco=60.4598+2.2572=62.7170(kJ/kg)
(5)喷嘴的出口汽流理想速度c1t
c1t=(2*Δhn(o))^0.5=(2*62.7170*1000)^0.5=354.17(m/s)
(6)喷嘴出口汽流实际速度c1
c1=φ*c1t=0.970*354.17=343.54(m/s)
(7)喷嘴损失δhn
δhn=(1-φ^2)*Δhn(o)=(1-0.970^2)*62.7170=3.5732(kJ/kg)
(8)圆周速度u
=π*dm*n/60=π*994.6/1000*3000.00/60=156.23(m/s)
(9)级的假想速度Ca
Ca=(2*Δht(o))^0.5=(2*66.8510*1000)^0.5=365.65(m/s)
(10)假想速比Xa
Xa=u/Ca=156.23/365.65=0.4273
(11)喷嘴等比熵出参数h1t
h1t=ho-Δhn=3244.3956-60.4598=3183.9358(kJ/kg)
(12)喷嘴前后压力比εn=P1/Po(o)=2.7683/3.4256=0.8081
(13)选取喷嘴型式和出汽角α1
选TC-1A喷嘴,出汽角α1=11°
(14)喷嘴出口面积An
An=G*V1t/μn/c1t=56.6802*0.1036/0.970/354.1700=0.0171(m^2)
(15)喷嘴高度ln
ln=An/(e*π*dm*sin(α1))
=0.0171/(1.0000*π*994.6/1000*sin11.00°)=28.7(mm)
(16)喷嘴出口实际比焓降h1
h1=h1t+δhn=3183.9358+3.5732=3187.5090(kJ/kg)
(17)动叶进口汽流角β1和相对速度w1
β1=arctg((c1*sin(α1)/(c1*cos(α1)-u))
=arctg(343.54*sin11.00°/(cos11.00°-156.23))=19.91°
w1=(c1^2+u^2-2*u*c1*cos(α1))^0.5
=(343.54^2+156.23^2-2*156.23*343.54*cos11.00°)^0.5=192.50(m/s)
(18)动叶理想比焓降Δhb
Δhb=Ωm*Δht=0.0640*64.5938=4.1340(kJ/kg)
(19)动叶滞止理想比焓降Δhb(o)
Δhb(o)=Δhb+δhw1=4.1340+18.5281=22.6621(kJ/kg)
(20)动叶出口理想汽流速度w2t
w2t=(2*Δhb(o))^0.5=(2*22.6621*1000)^0.5=212.89(m/s)
(21)动叶出口实际汽流速度w2
w2=ψ*w2t=0.931*212.89=198.20(m/s)
(22)动叶损失δhb
δhb=(1-ψ^2)*Δhb=(1-0.931^2)*4.1340=3.0195(kJ/kg)
(23)动叶后参数P2,V2
根据h2、P2查焓熵表得到
P2=2.7290Mpa,V2=0.1053m^
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