Influence on temperature profile in an oil film in thrust bearings using an embedded cooling circuitry beneath the pad surface: An experimental investigation

2019 ◽  
Vol 234 (5) ◽  
pp. 676-692
Author(s):  
FA Najar ◽  
GA Harmain
Keyword(s):  
Power Plants ◽  
Thrust Bearing ◽  
Lubricating Oil ◽  
Inlet Temperature ◽  
Water Cooling ◽  
Test Rig ◽  
Hydro Power ◽  
Oil Film ◽  
Cooling Circuit ◽  
Hydro Power Plants

This paper describes the design and development of a test rig, for the experimental assessment of performance characteristics of thrust bearing used in hydro power plants. This test rig has features to study experimentally the conventional pad-based thrust bearing and the newly designed water cooling enabled pad. In this paper, a cooling circuit designated as Circuit-I has been installed and then testing is performed. The shaft speed and axial load has been set at 1400 r/min and 5.0 kN. The lubricating oil used SAE-30 and inlet temperature of oil was maintained at 40℃. The main focus of the present work is to compute the influence on the temperature distribution in the oil film on the top surface of the pad with the embodiment of cooling circuit arrangement. From the experimental results, the overall reduction in the oil film temperature or on the top surface of the pad has been found to be 14% when the conventional thrust bearing set up is replaced by water cooling enabled pad of this kind.

Study of the Influence of Heat Convection Coefficient on Predicted Performance of a Large Tilting-Pad Thrust Bearing

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
M. Wodtke ◽  
M. Fillon ◽  
A. Schubert ◽  
M. Wasilczuk
Keyword(s):  
Power Plants ◽  
Thrust Bearing ◽  
Heat Convection ◽  
Lubricating Oil ◽  
Outer Diameter ◽  
Convection Coefficient ◽  
Hydro Power ◽  
Hydrodynamic Bearing ◽  
Lubricating Film ◽  
Thermal Deflection

Part of the heat generated by the shearing of the lubricating film during operation of a hydrodynamic bearing is transferred to the bearing components. In the case of the pad, which is usually fully submerged in the lubricating oil, heat is further transferred at the pad free walls to the oil by convection. This mechanism causes a thermal gradient in a pad and, consequently, its thermal deflection. In large hydrodynamic thrust bearings, thermal deflection of the pads is an important phenomenon influencing bearing performance. For such bearings, pad distortion can reach the level of hydrodynamic film thickness and can significantly change the bearing's properties. In this paper, the study of the influence of the heat convection coefficient on the predicted performance of a large hydrodynamic thrust bearing is presented. Two sets of convection coefficients at the pad free surfaces are investigated with the use of thermo-elasto-hydrodynamic (TEHD) calculations. An analysis is carried out for the Itaipu hydro turbine thrust bearing with the outer diameter equal to 5.2 m, which is one of the biggest hydro power plants in the world. The results of the theoretical predictions are compared to the measured data collected during bearing operation.

scholarly journals Effect of Symmetrically Switched Rectifier Topologies on the Frequency Regulation of Standalone Micro-Hydro Power Plants

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3201
Author(s):  
Henry Bory ◽  
Jose L. Martin ◽  
Iñigo Martinez de Alegria ◽  
Luis Vazquez
Keyword(s):  
Power Factor ◽  
Power Plants ◽  
Reactive Power ◽  
Alternating Current ◽  
Frequency Regulation ◽  
Hydro Power ◽  
Major Energy Source ◽  
Hydro Power Plants ◽  
Electronic Load ◽  
Ac Converters

Micro-hydro power plants (μHPPs) are a major energy source in grid-isolated zones because they do not require reservoirs and dams to be built. μHPPs operate in a standalone mode, but a continuously varying load generates voltage unbalances and frequency fluctuations which can cause long-term damage to plant components. One method of frequency regulation is the use of alternating current-alternating current (AC-AC) converters as an electronic load controller (ELC). The disadvantage of AC-AC converters is reactive power consumption with the associated decrease in both the power factor and the capacity of the alternator to deliver current. To avoid this disadvantage, we proposed two rectifier topologies combined with symmetrical switching. However, the performance of the frequency regulation loop with each topology remains unknown. Therefore, the objective of this work was to evaluate the performance of the frequency regulation loop when each topology, with a symmetrical switching form, was inserted. A MATLAB® model was implemented to simulate the frequency loop. The results from a μHPP case study in a small Cuban rural community called ‘Los Gallegos’ showed that the performance of the frequency regulation loop using the proposed topologies satisfied the standard frequency regulation and increased both the power factor and current delivery capabilities of the alternator.

scholarly journals Evaluation of Micro Hydro Power Plants in Central Java toward Sustainability against Hydrology Condition of Watershed

2018 ◽  
Vol 73 ◽  
pp. 01017
Author(s):  
Ignatius Sriyana
Keyword(s):  
Power Plant ◽  
Land Degradation ◽  
Power Plants ◽  
Hydro Power ◽  
Central Java ◽  
Hydro Power Plants

Land degradation on the upstream of watershed will affect hydrology condition in a way that it will disrupt the sustainability of its existing micro hydro. The purpose of this study is to evaluate micro hydro power plant in central Java toward sustainability against hydrology condition of watershed. This study is using River Regime Coefficient (RRC) approach where hydrology of watershed with coefficient value less than 50 is classified as non-critical, between 50 and 120 is moderate and more than 120 is critical. Result of the study that was done on 33 micro hydro power plants scattered on 9 watersheds is showing that there are 2 power plants on 2 watersheds have hydrology condition in non-critical status (9.09%), 1 power plant on 1 watershed is in between critical and non-critical status (3.03%), 21 power plants on 3 watersheds are in between critical and moderate status (63.64%), 8 power plants on 6 watersheds are in critical status (21.21%) and 1 power plant on 1 watershed is in between moderate and critical status (3.03%).

Application of Intelligent Technological Systems in Order to Increase Efficiency of the Lock Chamber System in Hydro Power Plants

2015 ◽  
Vol 806 ◽  
pp. 64-73
Author(s):  
Aleksandar Vujović ◽  
Zdravko Krivokapić ◽  
Jelena Jovanović
Keyword(s):  
Power Plants ◽  
Hydroelectric Power Plant ◽  
Global Market ◽  
Real System ◽  
Hydroelectric Power ◽  
Initial State ◽  
Hydro Power ◽  
Lock Chamber ◽  
Levels Of Automation ◽  
Hydro Power Plants

The paper is a result of research at the Mechanical Engineering Faculty in Podgorica and represents the aspiration of authors to combine scientific and technical experience in order to achieve improvement in a real system. It is a complex system of lock chambers in a hydroelectric power plant. Based on a detailed analysis of the initial state, through the process modeling of complex real system, the authors identify possible areas where the intervening and applying modern systems with greater flexibility is necessary to achieve higher levels of automation. Also, proposed in the paper are measures for ensuring the security of information that rise system performance to a higher level compared to the competition and create an advantage in the global market.

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