小容量超临界高背压汽轮机设计研究

RESEARCH ON DESIGN OF LOW-CAPACITY SUPERCRITICAL HIGH BACK-PRESSURE STEAM TURBINE

为了解决超临界火电机组外供次高压蒸汽设计方法的缺乏问题,文章针对小容量超临界高背压汽轮机的设计方法进行了研究。根据超临界蒸汽参数、背压和流量范围,发展了小容量超临界高倍压力汽轮机的热力计算和结构设计方法。利用该设计方法设计的汽轮机背压为4.0 MPa,功率等级为25 MW,汽量为241 t/h,其通流结构采用喷嘴子午面收缩型线,有效改善了短叶片引起损失大的问题,同时汽轮机采用了筒型汽缸结构,有效增强了汽轮机起停响应速度。此外,该设计方法还解决了筒型汽缸汽轮机的装配问题,可快速检验汽轮机设计的可行性。

In order to solve the problem concerning the lack of design methods for the external supply of secondary high-pressure steam to supercritical thermal power units,this paper studies the design methods for low-capacity supercritical high back-pressure steam turbines.Thermodynamic calculation and structural design methods for small-capacity supercritical high-multiplier-pressure turbines have been developed on the basis of supercritical steam parameters,back-pressures and flow ranges.The turbine designed with this method has a back pressure of 4.0 MPa,a power rating of 25 MW,and a steam capacity of 241 t/h.The nozzle meridian shrinkage profile was used in the flow structure,which effectively solved the problem of big loss caused by short blades.Meanwhile,the turbine adopted a barrel-type cylinder structure,which effectively enhances the response speed of turbine starting and stopping.In addition,the design method solved the problem of assembling the barrel-type cylinder turbine,which can check the feasibility of the turbine design quickly.