发布时间 : 星期二 文章300MW机组进行原则性热力系统计算更新完毕开始阅读
9） 由低压加热器DJ1、轴加SG和热井构成一整体的热平衡计算D8
D8??cpDc4(hw8?hc')??h??hwh8?hc'h8?hc'?''Ds7(hw7?hc)?Dsg4(hsg4?hc)
(0.81672D0?5.6723?103?0.9531DZP)(233.16?143.72)?0.999?2513?143.72(0.1095D0?0.7319?103?0.10064Dzp)(315.4?143.72)?1.42?103(3087?143.72)?2513?143.72
?0.0546D0?1.2352?103?0.0698Dzp
Ds8?Ds7?D8
?0.1095D0?0.7319?103?0.10064Dzp?0.0546D0?1.2352?103?0.0698Dzp
?0.1641D0?0.5033?103?0.17044Dzp
10） 由热井物质平衡求Dc
Dc?Dc4?Dt?Dma?Dsg4?Ds8
?0.81672D0?5.6723?103?0.9531Dzp?72.05?103?0.0149D0 ?1.42?103?0.1641D0?0.5033?103?0.17004Dzp ?0.64153D0?67.2642?103?0.7824Dzp
11） 计算D0
根据汽轮机最大工况时内功率，由汽轮机功率方程式求D0
Wi?(Pe??Pm??Pg)?3600
= (306930+3200+6439)×3600
?D0h0?Drhqrh??Djhj?Dchc??Dsgjhsgj
1284其中：
D0?D0 h0=3394.4 KJ/Kg
Drh?0.84231D0?8.4307?103?Dzp hrh=518.72 KJ/Kg
D1?0.06153D0?2.0438?103 h1=3151.8KJ/Kg D2?0.0942D0?3.0652?103 h2=3069.03 KJ/Kg D3?0.0243D0?8.6423?103 h3=3330.25 KJ/Kg
D4?0.0165D0?67.7328?103?0.0469Dzp h4=3151.62 KJ/Kg D5?0.452D0?0.3132?103?0.0340Dzp D6?0.0320D0?0.2023?103?0.0345Dzp D7?0.0311D0?0.2164?103?0.3214Dzp D8?0.0546D0?1.2352?103?0.0698Dzp Dc?0.63153D0?67.2142?103?0.7824DZP Dsg2?7.8?103 KJ/Kg Dsg3?4.42?103 KJ/Kg Dsg4?1.42?103 KJ/Kg 代入数据可得：D0=925.00－0.8448Dzp
h5=3048.48 KJ/Kg h6=2931.44 KJ/Kg h7=2725.05KJ/Kg h8=2516 KJ/Kg
hc=2335.51 KJ/Kg
hsg2=3339 KJ/Kg hsg3=3070 KJ/Kg hsg4=3087 KJ/Kg 4.2.2 工况二 再热蒸汽喷水流量Dzp=5t/h
4.2.2.1 各项流量列表
汽轮机汽耗量 D0'=D0=925.00－0.8442Dzp=920.779 t/h 锅炉蒸发量 Db=1.0101 D0 =930.0795 t/h
锅炉给水量 Dfw = 1.0202D0－33.46×103－Dzp =910.559 t/h Dfw ' = 1.0202D0－Dzp =939.379 t/h
锅炉排污量 Dbl=0.0101D0=9.300 t/h 锅炉未排污量 Dbl' =0.0048D0=4.641 t/h 扩容蒸汽量 Df=0.0053D0=4.659 t/h 全厂汽水损失 D1=0.01Db=9.300 t/h 系统补充水量 Dma=0.0149D0=13.942 t/h
再热蒸汽量 Drh=0.74113D0－8.431×103+ Dzp =785.111 t/h 各级换热器抽汽量
D1?0.06153D0?2.0438?103=51.024 t/h D2?0.0942D0?3.0652?103=72.514 t/h D3?0.0243D0?8.6423?103=23.026 t/h
D4?0.0165D0?67.9928?103?0.0469Dzp=62.624 t/h D5?0.0452D0?0.3132?103?0.0340Dzp=26.570 t/h D6?0.0320D0?0.2023?103?0.0345Dzp=27.080 t/h D7?0.0311D0?0.2163?103?0.03214Dzp=25.145 t/h D8?0.0546D0?1.2352?103?0.0698Dzp=53.200 t/h
汽轮机排汽量 Dc?0.64153D0?67.2642?103?0.7824Dzp＝562.626 t/h
'除氧器耗汽量 D4?0.0165D0?4.0527?103?0.0469Dzp＝27.224 t/h
通过进行热井物质平衡与汽轮机物质平衡求得凝汽流量Dc来进行计算误差检查。 热井物质平衡：
Dc?0.64153D0?67.2642?103?0.67167Dzp＝562.626 t/h 汽轮机物质平衡：
Dc?D0??Dj??Dsgj
#1284代入数据可得：
Dc?562.991 t/h
(Dc－Dc#)/ Dc=(562.626－562.991)/ 562.626=－0.06% 经检验，计算误差很小。 4.2.2.2 热经济指标计算
机组热耗量
puQ0?D0'h0?Drhqrh?Dfh'?Dmahma?Dfwhw1?Ddhw
#代入数据可得：Q0?2413025.949×103 KJ/h 机组热耗率 q?Q0/pe
=2413025.949×10/306930
3
=8253.200 KJ/(KW?h)
绝对电效率 ?e?3600/q=3600/7861.8120=0.436194 锅炉热负荷
'puQb?Dbhb?Drhqrh?Dblhbl?Dmahma?Dfwhw1?Ddhw
代入数据可得：Qb?2447260.084×103 KJ/h 管道效率 ?p?Q0/Qb
=2413025.949×103/(2447260.084×103) =0.9860
全厂热效率 ?cp??b??p??e =0.92×0.436194×0.9860 =0.396511
全厂热耗率 qcp?3600/?cp=3600/0.396511=8666.9716 KJ/(KW?h) 发电标准煤耗率 bs?0.123/?cp=0.123/0.396511=310.206×10-3
Kg/(KW?h)