发电厂原则性热力系统计算

1、再热蒸汽参数低压缸排汽压力给水泵小汽轮机耗汽份额:t=0.03158发电厂原则性热力系统计算举例例7-1亚临界600MW一次中间再热凝汽式汽轮机发电厂原则性热力系统计算。美国西屋电汽公司600MW亚临界机组的原则性热力系统如图7-15,求下列已知条件下机组发电机实际功率Pe=586.96MW时的全厂热经济指标。已知条件如下1 .汽轮机形式和参数美国西屋电汽公司制造的汽轮机，亚临界参数，一次中间再热，单轴，反动式,四缸四排汽，双背压，凝汽式机组，配汽包炉。机组型号TC4F-980初蒸汽参数P0=16.706MPat0=531.78C高压缸排汽Prh(t)=P2=3.2821Ma匕=t?=301.

2、72C再热器进口p；h(b)=3.2821MPa-298.72Pc=0.0045MPaXc=0.9056额定功率Pe=600MW回热系统参数该机组有八级回热抽汽，机组回热加热器为三高四低一除氧”，在机组发电机实际发出功率Pe=586.96MW下各回热抽泣的压力和温度，力口热器压力和疏水冷却器出口始见表7-1轴封及门杆参数该机组额定工况时轴封及门杆参数如7-2图统系力热性则原厂电发机轮汽式汽凝热再问中次一§O0界临亚？7图D器节调力压封轴表7-1TC4F-980型机组回热加热器参数项目单位回热加热器H1H2H3H4H5H6H7H8回热抽汽抽汽压力PiMPa5.61043.28211.6

3、0030.81070.39780.15150.05030.02865抽汽温度tjC377.48301.72441.08350.16269.38190.8688.8Xq8=0.9818加热器压力PjMPa5.61043.28211.60030.81070.39780.15150.05030.02865水加热器进口水温度twj+1C238.02203.78173.17140.89108.6885.3558.72一侧加热器进口水温度twjC274.92238.02203.78171.18140.89108.6885.3558.72加热器疏水温度twjc244.66205.54174.68一114.6

4、192.3366.0843.14表7-2TC4F-980型机组轴封及门杆流量参数序号符号来源点汇入点流量占比份额次含值(kJ/kg)1L高压缸轴封漏汽除氧器0.001843017.12L1高压缸轴封漏汽除氧器0.001623325.33M高压缸轴封漏汽轴封压力调机器0.0003963017.14M1高压缸轴封漏汽轴封压力调机器0.0003503325.35N高压缸轴封漏汽轴封加热器0.00005633017.16N1高压缸轴封漏汽轴封加热器0.00004983325.37A高压缸汽门门杆漏汽H20.00017433379.368B高压缸汽门门杆漏汽轴封加热器0.00007443379.369N

5、G高压缸浸缸H20.009953325.310K中压缸汽门门杆漏汽H30.004193538.711R中压缸轴封漏汽轴封加热器0.0001043134.912P中压缸轴封漏汽轴封压力调节器0.0005513134.913S轴封压力调节器低压缸轴封0.0007352716.214T低压缸轴封轴封加热器0.0003232716.215V轴封压力调节器热井0.005613150.316J高压缸排汽中压缸进汽0.004213020.52 .锅炉参数和形式锅炉型式美国巴威公司设计制造，亚临界，一次再热，自然循环，全悬吊平衡通风，单汽包，半露天煤粉炉。过热蒸汽出口参数pb=17.00lMPa,tb=533

6、.19c再热蒸汽进口参数p，b)=3.2821MPa只=298.72C再热蒸汽出口参数省煤器进口给水参数锅炉效率p，(b)=3.2821MPa,t；h(b)=298.72cp'fw=18.221MPatfw=273.56C1hfw=1184.36kJ/kg汽包连续排污流量份额锅炉排污水压力（汽包压力）排污扩容器工作压力b1=0.0028Pb1=18.08MPaPf=0.91MPa排污扩容器的热效率3.管道热力系统参数主蒸汽管道蒸汽泄漏份额t=0.981bo=0.0028再热蒸汽冷端管道蒸汽泄漏份额Lh(c)=0.0028厂用汽份额（汽源为高压缸排汽）:ap9h)=0.0028回水率：a

7、p（h）=0厂用汽份额（汽源为中压缸排汽）ap(t)i=09028回水率上0=0给水泵出口给水参数pt0=18.784MPat0P=173.17cp轴封加热器的疏水温度和进口给水始4.计算中采用的其他数据燃煤低位发热量机组的机电效率加热器效率厂用电率凝汽器凝结水温度凝结水泵出口水压力环境温度tsg=80.0C,h0P=137.15kJ/kgq1=21550kJ/kg0.98437mgmgh=0.98aD=0.045aptc=32.75Cp°p=2.8852MPat=25cb=0.9406补充水温度tma=25c,相应的比始hw,ma=104.77kJ/kg解：1 .整理原始数据的计算

8、点汽水始值新蒸汽，再热蒸汽及排污扩容器计算点参数如表7-3所示，根据汽轮机厂提供机组发电机功率Pe=586.96MW工况下的汽水参数，查表并整理出的汽水始值见表7-4所示，在始嫡图上作该机组的汽态线，如图7-16所示。图7-16TC4F-980型机组气态线2 .全厂物质平衡假设以高压缸进口蒸汽流量为基准，流量份额30=1。(1)计算锅炉连续排污扩容器产生的蒸汽量占比份额(该蒸汽最后引至除氧器)由于锅炉排污扩容器产生的蒸汽可能是饱和蒸汽，也有可能是湿蒸汽，在此假设产生的蒸汽干度"=0.97,则湿蒸汽的始值为_._.,_._hf=Xfhf(1-Xf)hf=0.972772.55(1-0.

9、97)744.70-2711.71(kJ/kg)由锅炉排污扩容器的热平衡方程可得到扩容器产生的蒸汽量为'-%1'1f=-fhf(-b1-f)hf*,.二:»(hb1f-hf)=0.0028(1738.040.98-744.7)=00014-f-hf-hf-2711.71-744.7-.(2)凝汽器补充水流量份额为-Ima=-：ap(h)(1-ap(h)-：ap(i)(1-ap(i)'(-：blf)b0-：rh(c)=0.0028(1-0)0.0028(1-0)(0.0028-0.0014)0.00280.0028=0.0127(3)锅炉省煤器进口给水流量比例份

10、额为二,：0二b。：b1=10.00280.0028=1.0056表7-3新蒸汽、再热汽及排污扩容器计算点汽水参数表汽水参数单位锅炉过热器（出口）汽轮机高压（入口）锅炉汽包排污水连续排污扩容器再热器压力pMPa17.00116.70618.080.913.2821（入口）3.218（出口）温度tC533.19531.78357.3175.8298.72(入口)538.64(出口)汽燃hkJ/kg3379.193365.86一2772.552982.22(入口)3540.18(出口)水焰hwkJ/kg一一1738.04744.70一再热蒸汽久含升qrhkJ/kg一一一一557.96表7-4美国西

11、屋电汽公司TC4F-980型机组回热系统计算点汽水参数项目单位回热加热器加热器编号H1H2H3H4H5H6H7H8SG排汽C加执八、器抽汽压力pjMPa5.61043.28211.60030.81070.39780.15150.05030.02865一0.0045温度tjC377.48301.72441.08350.16269.38190.8688.8Xc=0.98一Xc=0.905始hjkJ/kg3128.32987.83342.53161.63004.32854.52660.62588.19一23268.99P'下饱和水给hikJ/kg31044.970859.510726.130

12、723.345467.352381.530262.95172.18335.64137.15被加热水进口水始hwj+1kJ/kg996.92860.81729.99591.20423.96338.66213.71一一一出口水始hwjkJ/kg1185.13996.92860.81723.34591.20423.96338.66213.71一一疏水疏冷器出口水次含hd1'wjkJ/kg1044.97859.51726.13一467.35381.53262.95172.18一一3.计算汽轮机各段抽汽，加热器进口参数(1)由高压加热器H1热平衡计算ot1d：1(h1-hw1)h=二fw(hw1

13、-hw2)fw(hw1-hw2)/hh1-hw11.0056(1185.13-996.92)/098009273128.33-1044.33一.物质平衡的H1疏水份额c(s1二s1=11=0.0927(2)由高压加热器H2热平衡计算a2二：fw(hw2-hw3)ddddd、.二：2(卜2-hw2)"工A(hA-hw2)",NG(hlNG-hw2)"工s1(hw1-hw2)hdd、二fw(hw2-hw3)/h-二A(hA-hw2)-：NG(hNG-hw2)-：s1；二h2-hw2(2987.80-859.51)1.0056(996.92-860.81)/0.98-0

14、.0001743(3379.36-836.51)-0.00995(3325.3-859.51)-0.0927(1044.97-859.51)=0.0458物质平衡得H2疏水as2二s2二aa2aAHng=0.09270.04580.00017530.00995=0.1486再热蒸汽份额支th计算由高压缸的物质平衡可得：s2=：0-："A'：B'：N'：M'：L'：L1'：M1-：N1-：J'：NG-：1'：2'?ap(h)-?ap(c)=1-0.0001743-0.0000744-0.0000563-0.0003

15、96-0.00184-0.00162-0.00035-0.0000498-0.00421-0.00995-0.0927-0.0458-0.0028-0.0028=0.8372(3)由高压加热器H3热平衡口dddd、-：3(h3-'hw3)-：K(hK-'hw3)'；：s2(hw2-'hw3)h-fw(hw3hw4)'*fW(hw3Thw4)/h-K(hK-'hw3)-1s2(hw2-hw3)-：3=Hh3-hw31=1,0056(860.81-729.99)/0.98-0.00419(3538.7-726.13)(3342.50-726.13)-

16、0.1486(859.51-726.13)=0.0392物质平衡得H3疏水o(s3as3=as2a3ak=0.14860.03920.00419=0.1921(4)由除氧器H4热平衡计算值4以除氧器进水始为基准,根据除氧器的热平衡得;484一%5)二!_(>一八亚5);L1(hL1一二5):飞33一八亚5);f(hf一八亚5)一：fw(hw4一hw5)/h1d-4=7；-fw(hw4一hw5h-、L1(hL1-hw5)-L(hL-hw5)s3(hw3-hw5)-f(hf-hw5)(h4-hw5)1=1,0056(723.34-591,20)/0.98-0,00184(3017.1-591

17、.20)3161.6-519.20-0.00162(3325.3-591,20)-0.1921(726.13-591,20)-0.0014(2711.71-591.20)=0.0372除氧器进水量(主凝结水量)a。,，由除氧器物质平衡得：c4=：fw-14-1L-：L1-1s3-f=1.00560.03720.001840.001620.19210.0014=0.7716(5)由低压加热器H5热平衡计算覆55(hw5)h=二c4(hw5-hw6):c4(hW5-hW6”h0.7716(591.20-423.96)/0.9815=H=h5-h：53004.35-467.35=0.0519物质平衡

18、的H5疏水份额s5二s5=15=0.0519(6)由低压加热器H6热平衡计算口6«6(h6-h：6)+Qs5(h：5-46)3=%4亿6-hw7)二c4(hw6-hw7h-二飞54-6)he-hwe0.7716(423.96-338.66)/0.98-0.0519(467.35-381.53)2854.52-381.53=0.0254H6疏水as6;S6=二S5=6=0.05190.0254=0.0773(7)由低压加热器H7热平衡计算由«7(h7一hW?)+%63：6-h：7)h=ac4(hw7-hw8)dd、-c4(hw7-hw8)/h-s6(-w6-hw7)7h70.

19、7716(338.66-213.71)/0.98-0.0773(381.535-262.95)2660.6-262.95=0.0372H7疏水J7:s75s6：7=0.07730.0372=0.1145(8)由低压加热器H8,轴封冷却器SG构成一整体的热平衡计算a8ddd二8什8-hw8);s7(：w7-hw8);b3b-hsg);n”n-h$g)N1(hN1-hsg);1''pu、，R(hR-hsg)：T(hT-hsg)=:鹿4亿8-hw(J/h二8二(2581.19-172.18)0.7716(213.71-137.15)/0.98-0.1145(262.95-172.18)-0.0000744(3379.36-335.64)-0.0000563(3017.1-335.64)-0.0000498-335.64)=0.0200H8疏水8s8=：S718=0.11450.0220=0.1345(9)凝汽系数的计算1)由热井物质平衡得二,c二二，c4一1,s8TB一二,N一二,N1一二R一二,T一:，V一二，t-Hap(h)(1-：ab(h)工pq(i)"(:bl-f)-1