汽轮机汽封改造对经济指标和振动影响的测试分析

介绍了汽轮机梳齿汽封的密封原理和缺陷,以及刷式汽封、柔齿汽封两种新型汽封的工作原理、优点和在汽轮机轴系、通流部分中适合的部位。刷式汽封在汽轮机上的应用比较广泛,高、中、低压缸各部位均适合;柔齿汽封主要应用于轴端密封。由于这两种型式汽封密封间隙小,在汽轮机汽封改造中得到比较广泛应用。145 MW机组采用柔齿汽封改造后,满负荷工况下,机组高压缸效率提高3.77%,中压缸效率提高2.65%,热耗率降低321.2 kJ/kWh;220 MW机组采用刷式汽封改造后,满负荷工况下,机组高压缸效率提高2.23%,中压缸效率提高0.56%,热耗率降低290.44 kJ/kWh;330 MW机组采用柔齿汽封和刷式汽封相结合的改造方案后,满负荷工况下,热耗率降低265.84 kJ/kWh。

Test and Analysis of Impacts of Steam Seal Modification on Economic Index and Vibration of the Unit

Compared with serrate seal, the operational principle and advantage of brush seal and soft tooth seal are introduced, as well as the application position in rotor end and flow passage.Owing to small seal gap,brush seal and soft tooth seal are widely used in seal modification of HP,IP and LP cylinder,of which brush seal is widely used both in rotor end and flow passage,while soft tooth seal is mainly used in rotor end.After soft tooth seal modification,the efficiency of HP and IP of 145MW unit are increased by 3.77% and 2.65% operating under full load,with a 321.2k J/kWh decrease of heat consumption rate.After soft brush seal modification,the efficiency of HP and IP of 220MW unit are increased by 2.23% and 0.56% operating under full load ,with a 290.44kJ/kWh decrease of heat consumption rate.After mixed modification of soft tooth and brush seal, the heat consumption rate of 330MW is decreased by 265.84kJ/kWh with the unit operating under full load.