Probabilistic Analysis of Turbine Blade Tolerancing and Tip Shroud Gap

2012 ◽  
Author(s):  
P. Jafarali ◽  
Dmitry Krikunov ◽  
Amir Mujezinović ◽  
Nicholas A. Tisenchek
Keyword(s):  
Steam Turbine ◽  
Turbine Blade ◽  
A Priori ◽  
Design Parameters ◽  
Probabilistic Evaluation ◽  
Steam Turbine Blade ◽  
Dimensional Variation ◽  
Probabilistic Nature ◽  
Tip Shroud ◽  
The Impact

This paper consists of two parts. Part I presents a probabilistic based approach to determine an allowable manufacturing tolerance range on a steam turbine blade when the allowable Defects Per Million Opportunity (DPMO) are known a priori. The method allows simulating the entire row of blades with geometrical deviations by using only a few representative blade models. The proposed method takes into account the probabilistic nature of the dimensional variation within the tolerance ranges. Furthermore, the method allows the designer to understand the impact on critical blade design parameters. Part II of this paper proposes a probabilistic evaluation of gap / interference between shrouds of two adjacent blades of a steam turbine. The method uses manufacturing process capability of the relevant design parameter: tip shroud pitch for the tip shroud gap. This method allows for a probabilistic optimization of the shroud gap between two adjacent blades in order to balance reliability and ease of assembly.

scholarly journals Failure Analysis in Lacing Wire Of Last Stage Low Pressure Steam Turbine Blade

2021 ◽  
Vol 1096 (1) ◽  
pp. 012097
Author(s):  
A M Kongkong ◽  
H Setiawan ◽  
J Miftahul ◽  
A R Laksana ◽  
I Djunaedi ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Steam Turbine ◽  
Turbine Blade ◽  
Low Pressure ◽  
Pressure Steam ◽  
Steam Turbine Blade ◽  
Last Stage

Analytic Optimization of Cost Effective Thermoelectric Generation on Top of Rankine Cycle

2013 ◽  
Author(s):  
Kazuaki Yazawa ◽  
Yee Rui Koh ◽  
Ali Shakouri
Keyword(s):  
Steam Turbine ◽  
Fuel Efficiency ◽  
Cost Effective ◽  
Rankine Cycle ◽  
Energy Conversion Efficiency ◽  
Design Parameters ◽  
Steam Temperature ◽  
Combined System ◽  
Fuel Consumption Rate ◽  
The Impact

Thermoelectric (TE) generators have a potential advantage of the wide applicable temperature range by a proper selection of materials. In contrast, a steam turbine (ST) as a Rankine cycle thermodynamic generator is limited up to more or less 630 °C for the heat source. Unlike typical waste energy recovery systems, we propose a combined system placing a TE generator on top of a ST Rankine cycle generator. This system produces an additional power from the same energy source comparing to a stand-alone steam turbine system. Fuel efficiency is essential both for the economic efficiency and the ecological friendliness, especially for the global warming concern on the carbon dioxide (CO2) emission. We report our study of the overall performance of the combined system with primarily focusing on the design parameters of thermoelectric generators. The steam temperature connecting two individual generators gives a trade-off in the system design. Too much lower the temperature reduces the ST performance and too much higher the temperature reduces the temperature difference across the TE generator hence reduces the TE performance. Based on the analytic modeling, the optimum steam temperature to be designed is found near at the maximum power design of TE generator. This optimum point changes depending on the hours-of-operation. It is because the energy conversion efficiency directly connects to the fuel consumption rate. As the result, physical upper-limit temperature of steam for ST appeared to provide the best fuel economy. We also investigated the impact of improving the figure-of-merit (ZT) of TE materials. As like generic TE engines, reduction of thermal conductivity is the most influential parameter for improvement. We also discuss the cost-performance. The combined system provides the payback per power output at the initial and also provides the significantly better energy economy [$/KWh].

Studies on Determination of Natural Frequencies of Industrial Turbine Blades

1995 ◽  
Author(s):  
Mahesh M. Bhat ◽  
V. Ramamurti ◽  
C. Sujatha
Keyword(s):  
Steam Turbine ◽  
Dynamic Behavior ◽  
Turbine Blade ◽  
Natural Frequencies ◽  
Complex Structure ◽  
Turbine Blades ◽  
Blade Root ◽  
Steam Turbine Blade ◽  
Manufacturing Tolerances

Abstract Steam turbine blade is a very complex structure. It has geometric complexities like variation of twist, taper, width and thickness along its length. Most of the time these variations are not uniform. Apart from these geometric complexities, the blades are coupled by means of lacing wire, lacing rod or shroud. Blades are attached to a flexible disc which contributes to the dynamic behavior of the blade. Root fixity also plays an important role in this behavior. There is a considerable variation in the frequencies of blades of newly assembled turbine and frequencies after some hours of running. Again because of manufacturing tolerances there can be some variation in the blade to blade frequencies. Determination of natural frequencies of the blade is therefore a very critical job. Problems associated with typical industrial turbine bladed discs of a 235 MW steam turbine are highlighted in this paper.

Failure analysis of the 350MW steam turbine blade root

2009 ◽  
Vol 16 (4) ◽  
pp. 1270-1281 ◽  
Author(s):  
J. Kubiak Sz ◽  
J.A. Segura ◽  
G. Gonzalez R ◽  
J.C. García ◽  
F. Sierra E ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Steam Turbine ◽  
Turbine Blade ◽  
Blade Root ◽  
Steam Turbine Blade

Path Planning for Circular Cutter Envelop Milling of Steam Turbine Blade

2014 ◽  
Vol 989-994 ◽  
pp. 2908-2912
Author(s):  
Jian Jun Wang ◽  
Ke Wang ◽  
Qiong Wu
Keyword(s):  
Steam Turbine ◽  
Turbine Blade ◽  
Tool Path ◽  
Vertical Section ◽  
Surface Matching ◽  
Nurbs Surface ◽  
Processing Efficiency ◽  
Tool Paths ◽  
Blade Machining ◽  
Steam Turbine Blade

In order to solve the problem of poor steam turbine blade processing efficiency, and on the basis of analyzing the turbine blade surface and the existing processing methods, a model of circular cutter turbine blade machining is built. By comparing the tool paths of horizontal and vertical section envelope machining, choosing quasi-vertical cross section envelope machining method and utilizing the original datum and NURBS surface matching mathematic methods, this paper provides an algorithm of residual height calculating, and based on this, the tool path can be planned. Datum show that, the tool path of circular cutter machining blades is much longer than the tool path of ball-end cutter envelop milling machining blades, and the machining efficiency is also highly enhanced.

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