Numerical Study on Deformation of Gland Seal Housing at LP Ends on a Nuclear Steam Turbine

Author(s):  
Yanan Guo ◽  
Danmei Xie ◽  
Xiangjun Huang ◽  
Huabing Zheng ◽  
Ziyue Mei ◽  
...  

The rubbing between static and moving parts of steam turbine is one of the frequent faults and difficult to diagnose accurately. In the high-speed rotation of steam turbine, if the clearance between the static and moving parts is too small, there is a possibility of rubbing accident, especially for the ends of LP steam turbine in a nuclear power plant, which will affect the safety operation of the steam turbine. In this paper, the gland seal housing deformation of LP casing in 1000MW nuclear steam turbine is calculated and analyzed. Based on ProE and ANSYS/Workbench software, the 3D geometry model and the finite element mathematical model of LP inner casing of nuclear steam turbine are established, and the boundary conditions are determined at first. Secondly, the deformation of the gland seal housing at the LP casing end is calculated and analyzed under different conditions. Thirdly, the influence of different components temperature rise on the deformation of gland seal housing is analyzed.

Author(s):  
Daohui Ji ◽  
Ziyue Mei ◽  
Wei Jiang ◽  
CaiYan Xiang ◽  
Danmei Xie ◽  
...  

Abstract During installation process, most of 1000MW-class nuclear power steam turbines will undergo certain deformations due to their own big size and heavy weight, which will change seal clearances in the steam passage. The clearance change will affect steam turbine’s efficiency, and may cause rubbing faults and even strong abnormal vibration, affecting the safety of the steam turbine. Moreover, limited by the complex structure and measurement method, it is difficult to measure deformation and seal clearance accurately, so it is necessary to study the change tendency of the clearance in the installation process. In this paper, a HIP (High and Intermediate Pressure) casing of a 1000MW nuclear steam turbine was taken as the research object, and its 3D geometry model is established based on Pro/E software. By using ANSYS WORKBENCH, we calculated the deformation of the HIP casing during installation with five steps, which are named as: ① lower casing with lower diaphragms, ② step ① + upper diaphragms, ③ step ② + upper casing, ④ step ③ + bolting, and ⑤ replacing the support. Then we analyzed the change of the seal clearance during the installation process by deformation differences of some points under different conditions. The calculation results show that the maximum deformation of the HIP Casing during the installation process occurs in the middle of casing close to the IP (Intermediate Pressure) casing. The relative change of the clearance during the whole process is 0.6–0.8 mm. The change of seal clearance is largest at the first-stage of IP casing, and it can be 0.8mm during replacement of the support.


Author(s):  
E. Benini ◽  
A. Toffolo

The interaction between impeller and diffuser blades in high-speed centrifugal compressors is thought to have a significant influence on the flow within the diffuser. In this part, Computational Fluid Dynamics is exploited to simulate, visualize and analyze the complex flow generated by the interaction, with particular emphasis on the unsteady behavior of the vaned diffuser of the microturbine compressor studied in part 1. For this purpose, the 3D geometry of the compressor stage is studied by performing a fully unsteady simulation of rotor-stator interaction. The results of the unsteady calculation regarding the diffuser performance are then averaged in time and compared with those obtained with a fully steady and decoupled computation in order to highlight the main difference between the two approaches.


2019 ◽  
Vol 29 (8) ◽  
pp. 1101-1117
Author(s):  
Lin Yang ◽  
Xiangdong Li ◽  
Jiyuan Tu

Due to the fast development of high-speed rail (HSR) around the world, high-speed trains (HSTs) are becoming a strong competitor against airliners in terms of long-distance travel. Compared with airliner cabins, HST cabins have much larger window sizes. When the big windows provide better lighting and view of the scenery, they also have significant effects on the thermal conditions in the cabins due to the solar radiation through them. This study presents a numerical study on the solar radiation on the thermal comfort in a typical HST cabin. The effect of solar radiation was discussed in terms of airflow pattern, temperature distribution and thermal comfort indices. Parametric studies with seven different daytime hours were carried out. The effect of using the roller curtain was also studied. The overall cabin air temperature, especially near passengers, was found to have significantly increased by solar radiation. Passengers sitting next to windows were recorded to have an obvious thermal comfort variation at different hours of the day. To improve the passengers’ comfort and reduce energy consumption during hot weather, the use of a curtain could effectively reduce the solar radiation effect in the cabin environment.


Author(s):  
G. J. Parker ◽  
E. Bruen

This paper describes an investigation into the behaviour of drops which impinge upon dry and wet surfaces. This is of particular interest in the context of the wet steam turbine. Two approaches have been made in the studies; these are: (1) Drops were made to impinge normally on to various types of dry, stationary surfaces. The drops were in the size range 300–1500 μm diameter with velocities of 2–9 m/s. (2) Drops were made to impinge on to surfaces moving with considerable velocity at right angles to the motion of the drop. Surface velocities ranged up to 45 m/s. The latter study is of direct interest for the splashing of drops on turbine casings at small glancing angles, as occurs near drainage belts. Analysis of the mechanisms involved is made from the records of high-speed ciné photography.


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