Development and Application of Low Pressure Stages for Large Flow and High Speed Unit

New low pressure stages with twisted long blades were developed for 1000MW boiler feed water pump turbine (BFPT) of full capacity. The development process includes both CFD design and CAE design. Compared with half capacity, full capacity BFPT is now facing great market requirements. The difficulty lies in large flow of 100t/h and high speed of 5200rpm, which demands good strength and aerodynamic performance. The static stress and dynamic stress should be checked comprehensively. Air bending stresses of the twisted blades were calculated by three different methods. The fluid-solid coupling method for predicting air bending stress is better than traditional method, which can especially predict the effect of the blade root fillet and lacing convex on strength. The aerodynamic performance of the low pressure stages was given by variable condition calculation. Further improvements in efficiency were obtained by flow and structure optimization. This article describes the features and the development process of BFPT low pressure stages.Copyright © 2015 by ASME