Influence of Thermal and Mechanical Factors on the Stressed State of Large Components of Hydrogenerator-Motors
Journal Title: Проблеми машинобудування - Year 2018, Vol 21, Issue 3
Abstract
The work presented contains a detailed analysis of the existing ultimate power air-cooled hydrogenerator-motor design. It is shown that the umbrella-type hydrogenerator crosspiece perceives dynamic loads caused by forces acting in three planes. At the same time, to take them into account by analytical methods is impossible. In order to perform a three-dimensional calculation, it is necessary to take into account both the thermal and mechanical factors, as well as the specific features of the rolled metal. In the course of solving the problem set out above, taking into account thermal loads, a discrete crosspiece partition into the n-th number of sections is proposed. The convergence criterion for the solution to the inverse problem is based on maintaining the structure overall thermal balance, taking into account the limited accuracy of measuring devices. The main difference of the work was the justification of the choice of permissible stresses, taking into account the presence of bubbles in the metal structure, not exceeding their class of continuity for the selected rolled metal. It is proposed that an ‘elementary defect’ be introduced into the zone with the lowest safety margins as a circle with geometric data according to the restrictions on continuity. In this case, the correction of the selection of the finite element mesh parameters for the introduced defect is carried out as for the plate with eccentrically located holes. The mesh reduction continues to be carried out until the moment when the difference in the maximum stresses in the same mesh nodes is no more than 0.04%. Mechanical loads are specified in the classical formulation. In the course of the work it was found that the strength reserves of large generator components should be regulated by the quality of the rolled metal used, and the mechanical calculations should take into account thermal factors.
Authors and Affiliations
Aleksey Tretyak, Aleksandr Shut, Pavel Gakal
Keywords
Related Articles
- EP ID EP622085
- DOI 10.15407/pmach2018.03.031
- Views 54
- Downloads 0
Modeling Heat and Mass Exchange Processes in Metal-hydride Installations
Hydrogen as an environmentally friendly energy carrier is increasingly used in various sectors of the economy of industrialized countries, primarily to improve the environmental situation. Regardless of the field of appl...
New Generation 'Block-Modular' Condenser for K-1000-60 / 1500-2 Turbine Units in Zaporozhskaya NPP
<p class="a"><span lang="EN-US">The condensing devices of steam turbine plants considerably determine the reliable and economical operation of NPP power units. In some cases, breakdowns in their operation result in a for...
Vibration Features of Titanium Alloy Blades with Erosive Damages
This paper deals with erosive damage influence on the vibration features of the working blades of the fifth-stage of the low pressure cylinder (LPC) of a K-1000-60/3000 steam turbine for a nuclear power plant (NPP). The...
Thermostressed State of the Lock Joint of Turbine Rotor Blades of the First Stage of К-500-240 Steam Turbine Medium Pressure Cylinder
This paper investigates the temperature field effect on the stress state of the turbine rotor blade lock joint elements where breakdowns were observed. The turbine rotor blade joint, when heat is supplied from the steam...
Solution to Non-stationary Inverse Heat Conduction Problems for Multi-layer Bodies, Based on Effective Search for the Regularization Parameter
To obtain a stable solution to the inverse heat conduction problem (IHCP), the article uses A. N. Tikhonov's method with an effective algorithm for finding the regularization parameter. The required heat flux at the boun...