?357.2?258.7???7?2614.5?366.85??0.100903??546.89?366.85???0.99?0.764912
?7?0.02578
H7的疏水系数
?d7??d6??7?0.100903?0.02578?0.12668
(8)8号低压加热器(H8)与轴封加热器(SG)
为了计算方便,将#8加热器和轴封加热器可作为整体考虑,采用图2-39所示的热平衡范围来列出物质平衡和热平衡式,由热井的物质平衡式,可得
?c??pu??c4??d7??sg2??8根据?
吸热量=?放热量写出热平衡式
hc''?c4hw8??8h8??sg2hsg2??d7h7?(?c??pu)hc'将
?c??pu消去,并整理成以
?c4
吸热为基础以进水焓为基准的热平衡式,
'得[?8(h8?hc')??d7(h7?hc')??sg2(hsg2?hc')]ηh??c4(hw8?hc')
?8???c4?hw8?hc'?/?h??d7?h7'?hc'???sg2?hsg2?hc'?h8?hc'0.764912??258.7?133.14?/0.99?0.12668??366.85?133.14??0.0014??3194.4?133.14?2481.7?133.14?0.026876
(9)凝汽器系数?c的计算与物质平衡校核 由热井的物质平衡计算?c
?c??c4??d7??sg2??8??pu?0.764912?0.12668?0.02792?0.038?0.572
由汽轮机通流部分物质平衡来计算
?8??c?1????j??sg1??sg2??1?
?c,以校核计算的准确性
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?0.119?0.032111?0.057358??0.0526297???1???0.042811?0.05809?0.02578?0.026876?0.013?0.0014???
?0.572 二者相等,说明计算正确
2.2.3汽轮机汽耗量及各项汽水流量的计算
?qrh?hrh2?hrh1?3658.50?3114.64?543.86?kj/kg?
?ic?h0?hc??qrh?3457.68?2310.8?543.86?1690.74?kj/kg?
表2-7 作功不足系数计算
Y的计算式 Yi ?i 0.0516197 0.119 0.032111 0.057358 0.042811 0.05809 0.02578 0.026876 ?iYi 0.04314 0.09464 0.0204 0.02965 0.0182 0.01806 0.00463 0.00272 0.23144 Y1??h1?hc??qr.h?/?hr.h Y2??h2?hc??qr.h?/?hr.h Y3??h3?hc?/?hr.h Y4??h4?hc?/?hr.h Y5??h5?hc?/?hr.h 0.8357 0.7953 0.6352 0.5169 0.4251 0.3109 0.1796 0.1011 Y6??h6?hc?/?hr.h Y7??h7?hc?/?hr.h Y8??h8?hc?/?hr.h ??Y iii?18汽轮发电机组汽耗量
3600?6.8?105Dc0?10??10?3?1656.85t/h
?ic?m?g1690.74?0.996?0.99063600pe?3抽气做功不足汽耗增加系数β为
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821????1/?1???jYj???sgjYsgj???1.313984
11??1?0.23144?0.007516则D0?Dc0??1656.85?1.313984?2177.079t/h
2.2.4功率核算
2-8 功率核算表
?j hj ?jhj 164.15 ?j hj ?jhj 84.58 ?1?0.0516197 3179.9 ?7?0.02578 ?8?0.026876 2614.5 ?2?0.119 ?3?0.032111 ?4?0.057358 ?5?0.042811 ?6?0.05809 3111.6 3384.8 3184.7 3029.5 2836.4 370.28 108.69 182.67 129.696 164.77
2481.7 2310.8 3193.2 3194.4 66.698 1322.47 41.51 4.47 ?c?0.5723 ?csg1?0.013 ?sg1?0.0014 ?ah?2639.984 1 kg新汽比内功wi(其中?81ajhj计算数据见表)为
2wi?h0??rhqrh?(??jhj??chc??sgjqsgj)1
=3457.68+0.8293803×543.86-2639.984=1361.556 据此,可得汽轮发电机的功率Pe'为
'pe?D0?i?m?g/3600?690.44MW
'/pe?100%?680?690.44/680?100%?0.01535% 计算误差??pe?pe误差非常小,在工程允许范围内,表示上述计算正确。
表2-9各项汽水流量,抽汽及排汽内功率
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项目 汽轮机汽耗D0?D0? D0 锅炉蒸发量Db?1.0101D0 给水量Dfw?1.0101
数量(t/h) 2177.09 2198.86 2198.86 30.051627 全厂汽水损失Di?0.010101D0 D0 化学补充水量Dma?0.01010130.051627 1792.29 再热蒸汽量Drh?0.829836D0-14335.2
表2-10 各段抽汽量
项目 第一段抽汽D1 第二段抽汽D2 第三段抽汽D3 第四段抽汽D4 第五段抽汽D5 第六段抽汽D6 第七段抽汽D7 第八段抽汽D8 汽轮机排汽Dc D(kg/h) 抽汽量(t/h) 155.360453 350.896846 126.293598 268.281288 132.413399 144.200801 89.048137 90.833187 1614.838524 (内功率W ijkj/h)46949.9289?103 130007.2814?103 81648.80529?103 227126.9384?103 132651.7431?103 172305.5371?103 126163.4005?103 140755.1066?103 2778329.681?103 h(kj/kg) h0?3482.1 D0 15
Drh?0.829836D0-14335.2 D1?0.052220D0 D2?0.117944D0 D3?0.042450D0
qrh?549.2 h1?3179.9 h2?3111.6 h3?3384.8 h4?3184.7 D4?0.033670D0?168109.2 D5?0.044507D0 D6?0.048469D0 D7?0.029931D0 h5?3029.5 h6?2836.4 h7?2614.5 h8?2481.7 hc?2310.8 D8?0.030930D0-1187.088297 Dc?0.599878D0-169866.9117 .1117 ?Dj?0.400121D0?16692218 D(kg/h) Dsg1?910.8 Dsg2?2034 H(kj/kg) hsg1?3193.2 hsg2?3149.4 ?D12sgj?2944.8
2.2.5全厂热经济性指标计算
电机组热经济性指标计算
1kg新汽的热耗量q
?kj/kg?q?h0??rhqrh?hfw?3457.68?0.8293803?543.86?1310.5?2598.24677
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