scholarly journals Shafting Alignment Computing Method of New Multibearing Rotor System under Specific Installation Requirement

2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Qian Chen ◽  
Qi Yuan ◽  
Ming Lei ◽  
Mengyao Wang
Keyword(s):  
Mathematical Model ◽  
Steam Turbine ◽  
Bending Moment ◽  
Moment Equation ◽  
Rotor System ◽  
Turbine Generator ◽  
Calculation Results ◽  
Computing Method

The shafting of large steam turbine generator set is composed of several rotors which are connected by couplings. The computing method of shafting with different structure under specific installation requirement is studied in this paper. Based on three-moment equation, shafting alignment mathematical model is established. The computing method of bearing elevations and loads under corresponding installation requirements, where bending moment of each coupling is zero and there exist preset sag and gap in some couplings, is proposed, respectively. Bearing elevations and loads of shafting with different structure under specific installation requirement are calculated; calculation results are compared with installation data measured on site which verifies the validity and accuracy of the proposed shafting alignment computing method. The above work provides a reliable approach to analyze shafting alignment and could guide installation on site.

scholarly journals Vibration Responses of a Coaxial Dual-Rotor System with Supporting Misalignment

2021 ◽  
Vol 11 (23) ◽  
pp. 11219
Author(s):  
Hongxian Zhang ◽  
Xuejun Li ◽  
Dalian Yang ◽  
Lingli Jiang
Keyword(s):  
Dynamic Characteristics ◽  
Weight Ratio ◽  
Bending Moment ◽  
Element Model ◽  
Rolling Bearing ◽  
Moment Equation ◽  
Rotor System ◽  
Structural Deformation ◽  
Model Studies ◽  
Bearing Loads

In order to improve the thrust-weight ratio, modern aeroengines generally adopt a coaxial dual-rotor system. Factors such as manufacturing errors, assembly errors, bearing wear, and structural deformation can cause misalignment failures in a dual-rotor system. Supporting misalignment is one of the common types of misalignments in a dual-rotor system. To analyze the vibration characteristics of misalignment faults, in this study, we aim to build a finite element model of a dual-rotor system with supporting misalignment. The bearing loads caused by supporting misalignment are calculated using the three-bending moment equation method. Bearing loads are introduced into the dynamic model of the dual-rotor system. The influence of supporting misalignment at different bearings on the dynamic characteristics of the rotor system is investigated based on the supporting misalignment model. Studies have shown that supporting misalignment at different bearings has similar effects on the dynamic characteristics of the dual-rotor system. The proposed supporting misalignment model is more adaptable than the coupling misalignment model. It indicates that the damping of a rolling bearing should be considered in the dynamic analysis of a dual-rotor system although the value of the damping is not large. An experimental analysis is carried out. The simulation results are in good agreement with the experimental results.

scholarly journals Analytical Method for Geometric Nonlinear Problems Based on Offshore Derricks

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 610
Author(s):  
Chunbao Li ◽  
Hui Cao ◽  
Mengxin Han ◽  
Pengju Qin ◽  
Xiaohui Liu
Keyword(s):  
Analytical Method ◽  
Bending Moment ◽  
Nonlinear Problems ◽  
Weather Conditions ◽  
Order Effect ◽  
Practical Calculation ◽  
Geometrically Nonlinear ◽  
Uniform Load ◽  
Safety Research ◽  
Calculation Results

The marine derrick sometimes operates under extreme weather conditions, especially wind; therefore, the buckling analysis of the components in the derrick is one of the critical contents of engineering safety research. This paper aimed to study the local stability of marine derrick and propose an analytical method for geometrically nonlinear problems. The rod in the derrick is simplified as a compression rod with simply supported ends, which is subjected to transverse uniform load. Considering the second-order effect, the differential equations were used to establish the deflection, rotation angle, and bending moment equations of the derrick rod under the lateral uniform load. This method was defined as a geometrically nonlinear analytical method. Moreover, the deflection deformation and stability of the derrick members were analyzed, and the practical calculation formula was obtained. The Ansys analysis results were compared with the calculation results in this paper.

scholarly journals Mathematical model and calculation results of the kerosene aerosol combustion rate

2020 ◽  
Vol 1565 ◽  
pp. 012022
Author(s):  
V A Poryazov ◽  
K M Moiseeva ◽  
A Yu Krainov ◽  
D A Krainov
Keyword(s):  
Mathematical Model ◽  
Combustion Rate ◽  
Calculation Results

Effect of Torsion on Collapse Bending Moment for 24-Inch Diameter Schedule 80 Pipes With Wall Thinning

2012 ◽  
Author(s):  
Kunio Hasegawa ◽  
Yinsheng Li ◽  
Bostjan Bezensek ◽  
Phuong Hoang
Keyword(s):  
Power Plants ◽  
Bending Moment ◽  
Combined Loading ◽  
Bending Moments ◽  
Compressive Stresses ◽  
Wall Thinning ◽  
Nominal Thickness ◽  
Calculation Results ◽  
Loading Modes ◽  
Local Wall Thinning

Piping items in power plants may experience combined bending and torsion moments during operation. Currently, there is a lack of guidance in the ASME B&PV Code Section XI for combined loading modes including pressure, torsion and bending. Finite element analyses were conducted for 24-inch diameter Schedule 80 pipes with local wall thinning subjected to tensile and compressive stresses. Plastic collapse bending moments were calculated under constant torsion moments. From the calculation results, it can be seen that collapse bending moment for pipes with local thinning subjected to tensile stress is smaller than that subjected to compressive stress. In addition, equivalent moment is defined as the root the sum of the squares of the torsion and bending moments. It is found that the equivalent moments can be approximated with the pure bending moments, when the wall thinning length is equal or less than 7.73R·t for the wall thinning depth of 75% of the nominal thickness, where R is the mean radius and t is the wall thickness of the pipe.

Sir Charles Parsons and Electrical Power Generation—a Turbine Designer's Perspective

1994 ◽  
Vol 208 (3) ◽  
pp. 159-176 ◽  
Author(s):  
J R Bolter
Keyword(s):  
Power Generation ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Electrical Power Generation ◽  
Analytical Methods ◽  
State Of The Art ◽  
Electrical Power ◽  
Turbine Generator ◽  
Current State ◽  
The World

Sir Charles Parsons died some three years after the author was born. In this paper the author looks back at the pioneering work of Parsons in the field of power generation. It shows how he was able to increase output of the steam turbine generator from 7.5 kW in 1884 to 50000 kW in 1930 while increasing efficiency from 1.6 to 36 per cent, and relates these achievements to the current state of the art. Blading design, rotor construction and other aspects of turbine engineering are considered. The conclusion is that Parsons and his associates charted the course which manufacturers and utilities throughout the world have continued to follow, although increasingly sophisticated design and analytical methods have succeeded the intuitive approach of Parsons. His constant search for improved efficiency was and is highly relevant to today's concern for the environment. Finally, although it did not become a practical proposition in his lifetime, the paper reviews Parsons' vision of, and continuing interest in, the gas turbine, first mentioned in his 1884 patents.

A Digital Computer Program for Processing Turbine-Generator Acceptance Test Data

1962 ◽  
Vol 84 (3) ◽  
pp. 295-304 ◽  
Author(s):  
G. A. Maneatis ◽  
W. H. Barr
Keyword(s):  
Thermodynamic Properties ◽  
Computer Program ◽  
Steam Turbine ◽  
Test Data ◽  
Digital Computer ◽  
Heat Rate ◽  
Acceptance Test ◽  
Turbine Generator

This paper describes a digital computer program which processes rapidly all of the data taken during a steam turbine-generator acceptance test. Specifically, it determines all thermodynamic properties of steam and water, computes corrected test heat rate, and finally develops a contract heat rate for purposes of comparison with manufacturer’s guarantees. The application of this program on two 330-megawatt units is discussed. The thinking leading to certain key decisions involving the ultimate approach taken is presented for the benefit of those contemplating a similar effort.

scholarly journals ПОБУДОВА МАТЕМАТИЧНОЇ МОДЕЛІ СКЛАДНОГО РУХУ ФЛАКОНІВ НА ЛІНІЯХ РОЗЛИВУ ЛІКІВ ФАРМАЦЕВТИЧНОЇ ПРОМИСЛОВОСТІ

2012 ◽  
Author(s):  
N. О. Kravets
Keyword(s):  
Mathematical Model ◽  
Experimental Evaluation ◽  
Theoretical Dependence ◽  
Complex Product ◽  
Lateral Lines ◽  
Calculation Results ◽  
The Mathematical Model

The  mathematical model of the complex product motion along the lateral lines at the plate conveyers of the bottle lines is presented in the artcle. The experimental evaluation of the gained theoretical dependence is suggested.   The calculation results coordinate well with the modelling and experiment resuls.

scholarly journals The influence of reinforcement temperature on stiffness of reinforced concrete beams in fire conditions

2013 ◽  
Vol 12 (1) ◽  
pp. 115-122
Author(s):  
Michał Głowacki ◽  
Marian Abramowicz ◽  
Robert Kowalski
Keyword(s):  
High Temperature ◽  
Cross Section ◽  
Static Load ◽  
Concrete Beams ◽  
Bending Moment ◽  
Reinforced Concrete Beams ◽  
Temperature Influence ◽  
Calculation Results ◽  
Tensile Zone ◽  
In Fire

This paper describes the analysis of high temperature influence on beams with heated tensile zone. High temperature experiments were preformed under the static load of 50 or 70% of the destructive force ensuring constant value of bending moment in the central part of the heated beam. Beams with 2 reinforcement ratios – 0.44 and 1.13% were examined. In total four series of beams, three in each series (12 elements) were used. This paper analyses the reduction of relative beam cross section stiffness depending on reinforcement temperature. Experimentally obtained stiffness values calculated in two ways (element maximal deflection and deflection measured in three points of analysed element) were compared to calculation results made according to Eurocode. The performed analysis shows that reduction of the stiffness of element based on Eurocode calculations is slightly bigger than the experimentally obtained one.

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