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Jiang X.,Zhejiang University | Wang J.,Zhejiang University | Fang J.,Zhejiang Fuchunjiang Hydropower Equipment Co.
Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology | Year: 2011

The effects of elastic deformation of pad surface, rotational speed, axial load, and oil viscosity grade on tilting pad thrust bearing performance were analysed using the model of thermal elastohydrodynamic lubrication. The Reynolds equation, the viscosity-temperature and density-temperature characteristics of the lubricants, film thickness equation, energy equation, heat conduction equation, and elastic deformation equation were simultaneously solved with the finite-difference method. The results showed that the maximum pressure is reduced and the minimum film thickness is decreased, when pad deformation is taken into account. The rotational speed has significant effects on the film thickness and temperature, however, slight effects on hydrodynamic pressure. The heavier load leads to an increase in the maximum pressure and a decrease in the film thickness, and the temperature is slightly affected by the load. The oil film with higher viscosity grade has a higher load-carrying capacity, and consumes much more energy than those of low-viscosity fluid. Source


Wang H.,Zhejiang University | Zong R.,Zhejiang Fuchunjiang Hydropower Equipment Co. | Liu L.,Zhejiang University | Yang S.,Zhejiang University
2014 17th International Conference on Electrical Machines and Systems, ICEMS 2014 | Year: 2015

Accurate and precise determination of 3D eddy current and temperature fields of a large hydro-generator has always been a formidable challenge to engineers and academicians. In this regard, the full three dimensional (3D) finite element models and methods are developed for numerical solutions of the coupled eddy current and temperature fields in the end region of a large hydro-generator. The equivalent medium parameters used in the computations are then comprehensively discussed. The methodology to determine the field and phase currents under different operating states is also presented. Moreover, an approach to effectively deal with the thin skin-depth is introduced. Numerical results on the coupled eddy current and temperature fields in the end region of a 100 MW hydro-generator in three different operating conditions confirm positively the feasibility of the present work. © 2014 IEEE. Source


Zhang Q.,Beijing Jiaotong University | Yan J.,Zhejiang Fuchunjiang Hydropower Equipment Co. | Wang M.,Zhejiang Fuchunjiang Hydropower Equipment Co. | Chen Z.,Zhejiang Fuchunjiang Hydropower Equipment Co.
Advanced Materials Research | Year: 2012

Averaged 3D N-S equations and RNG k-ε equations were solved with parallel computing CFD code on the flow field of dual radial ventilation system without fan for a hydro-generator. The MRF(multiple implicit rotating frame) method was used to simulated the rotating motion of the generator and porous media model were used to simulate the pressure loss of air cooler. Rational tactics were selected to generate calculation grids to compromise with calculation CPU time and result accuracy and the grids of different parts were generated with ICEM-CFD. The flow characteristic of different parts was analyzed and flow flux of different section was obtained. The research indicated that the flow from leakage gap between poles and stators formed "air wall", which generated a recirculation zone and made the bar cooling bad. The local pressure loss of stator entrance is dominant. There are leeward and windward areas for the air flowing with circumferential velocity component. Rational design of stator ducts entrance with some diversion effect, can reduce the pressure loss of the stator ventilation and improve the cooling of leeward area in stator ducts. Source


Wu H.,Xian University of Technology | Feng J.J.,Xian University of Technology | Wu G.K.,Xian University of Technology | Wu G.K.,Zhejiang Fuchunjiang Hydropower Equipment Co. | And 2 more authors.
IOP Conference Series: Earth and Environmental Science | Year: 2012

In this paper, the flow field considering the hub clearance flow in a Kaplan turbine has been investigated through using the commercial CFD code ANSYS CFX based on high-quality structured grids generated by ANSYS ICEM CFD. The turbulence is simulated by k-ω based shear stress transport (SST) turbulence model together with automatic near wall treatments. Four kinds of simulations have been conducted for the runner geometry without hub clearance, with only the hub front clearance, with only the rear hub clearance, and with both front and rear clearance. The analysis of the obtained results is focused on the flow structure of the hub clearance flow, the effect on the turbine performance including hydraulic efficiency and cavitation performance, which can improve the understanding on the flow field in a Kaplan turbine. © Published under licence by IOP Publishing Ltd. Source


Zhang Q.,Beijing Jiaotong University | Cui H.,Beijing Jiaotong University | Yan J.,Zhejiang Fuchunjiang Hydropower Equipment Co. | Wang M.,Zhejiang Fuchunjiang Hydropower Equipment Co. | Chen Z.,Zhejiang Fuchunjiang Hydropower Equipment Co.
Advanced Materials Research | Year: 2012

Reynolds averaged Navier-Stokes (RANS) equations, energy equation and V2f turbulence model equations governing the flow field of the rotor frame, magnetic yoke and the pole, the stator were solved with finite volume method(FVM) based on unstructured mesh. The MRF(multiple implicit rotating frame) method was used to simulated the rotating motion of the rotor frame, magnetic yoke and the pole. The flow characteristic of different parts was analyzed. The influence of the gap size between insulating layer of bar core, the gap size between insulating layer of pole and coil to the temperature distributions on the solid parts was studied. The results show that the temperature on the windward of the pole is lower than the temperature on the leeward. With the gap size between the insulating layer of bar and core varying from 0.0mm to 0.3mm, the temperature of insulating layer of bar rise increases 9.2 degrees, So the gap size is important for the life of insulating layer. With the gap size between the insulating layer of pole and the coil varying from 0.25mm to 0.75mm, the temperature of coil increases 16.5 degrees. The results provide a reference for the rational design of the gap size. Source

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