Numerical Investigation of a Full Load Operation Point for a Low Head Propeller Turbine

2016 ◽  
pp. 435-447
Author(s):  
Bernd Junginger ◽  
Stefan Riedelbauch
Keyword(s):  
Numerical Investigation ◽  
Full Load ◽  
Full Load Operation ◽  
Low Head

Stabilizing a 46 MW Multistage Utility Steam Turbine Using Integral Squeeze Film Bearing Support Dampers

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Bugra Ertas ◽  
Vaclav Cerny ◽  
Jongsoo Kim ◽  
Vaclav Polreich
Keyword(s):  
Steam Turbine ◽  
Critical Speed ◽  
Stability Margin ◽  
Experimental Tests ◽  
Turbine Rotor ◽  
Squeeze Film ◽  
Full Load ◽  
Vibration Data ◽  
Full Speed ◽  
Full Load Operation

A 46 MW 5500 rpm multistage single casing utility steam turbine experienced strong subsynchronous rotordynamic vibration of the first rotor mode; preventing full load operation of the unit. The root cause of the vibration stemmed from steam whirl forces generated at secondary sealing locations in combination with a flexible rotor-bearing system. Several attempts were made to eliminate the subsynchronous vibration by modifying bearing geometry and clearances, which came short of enabling full load operation. The following paper presents experimental tests and analytical results focused on stabilizing a 46 MW 6230 kg utility steam turbine experiencing subsynchronous rotordynamic instability. The paper advances an integral squeeze film damper (ISFD) solution, which was implemented to resolve the subsynchronous vibration and allow full load and full speed operation of the machine. The present work addresses the bearing-damper analysis, rotordynamic analysis, and experimental validation through waterfall plots, and synchronous vibration data of the steam turbine rotor. Analytical and experimental results show that using ISFD improved the stability margin by a factor of 12 eliminating the subsynchronous instability and significantly reducing critical speed amplification factors. Additionally, by using ISFD the analysis showed significant reduction in interstage clearance closures during critical speed transitions in comparison to the hard mounted tilting pad bearing configuration.

Stabilizing a 46 MW Multi-Stage Utility Steam Turbine Using Integral Squeeze Film Bearing Support Dampers

2014 ◽  
Author(s):  
Bugra Ertas ◽  
Vaclav Cerny ◽  
Jongsoo Kim ◽  
Vaclav Polreich
Keyword(s):  
Steam Turbine ◽  
Critical Speed ◽  
Stability Margin ◽  
Experimental Tests ◽  
Turbine Rotor ◽  
Squeeze Film ◽  
Full Load ◽  
Vibration Data ◽  
Multi Stage ◽  
Full Load Operation

A 46 MW 5,500 rpm multistage single casing utility steam turbine experienced strong subsynchronous rotordynamic vibration of the first rotor mode; preventing full load operation of the unit. The root cause of the vibration stemmed from steam whirl forces generated at secondary sealing locations in combination with flexible rotor-bearing system. Several attempts were made to eliminate the subsynchronous vibration by modifying bearing geometry and clearances, which came short of enabling full load operation. The following paper presents experimental tests and analytical results focused on stabilizing a 46 MW 6,230kg utility steam turbine experiencing subsynchronous rotordynamic instability. The paper advances an integral squeeze film damper (ISFD) solution, which was implemented to resolve the subsynchronous vibration and allow full load and full speed operation of the machine. The present work addresses the bearing-damper analysis, rotordynamic analysis, and experimental validation through waterfall plots, and synchronous vibration data of the steam turbine rotor. Analytical and experimental results show that using ISFD improved the stability margin by a factor of 12 eliminating the subsynchronous instability and significantly reducing critical speed amplification factors. Additionally, by using ISFD the analysis showed significant reduction in interstage clearance closures during critical speed transitions in comparison to the hard mounted tilting pad bearing configuration.

scholarly journals Performance Analysis of a Producer Gas-fuelled Heavy-duty SI Engine at Full-load Operation

2015 ◽  
Vol 82 ◽  
pp. 149-155 ◽  
Author(s):  
Paolo Gobbato ◽  
Massimo Masi ◽  
Marianna Benetti
Keyword(s):  
Performance Analysis ◽  
Producer Gas ◽  
Heavy Duty ◽  
Si Engine ◽  
Full Load ◽  
Full Load Operation

scholarly journals FEV HiFORS: A new passenger car Diesel injector with continuous rate shaping for 2500 bar injection pressure

2014 ◽  
Vol 157 (2) ◽  
pp. 36-44
Author(s):  
Paul GRZESCHIK ◽  
Hermann-Josef LAUMEN
Keyword(s):  
Engine Performance ◽  
Injection Pressure ◽  
Combustion Noise ◽  
Part Load ◽  
Full Load ◽  
High Pressure High Temperature ◽  
Rate Shaping ◽  
Full Load Operation ◽  
Material Choice ◽  
Operating Points

This paper presents the HiFORS continuously rate shaping injector for injection pressures of 2500 bar and above developed by FEV GmbH and the Institute for Combustion Engines, RWTH Aachen University. The development process from concept definition to hydraulic and deisgn layout, material choice and manufacturing is discussed. The hydraulic operating properties are verified by injection test rig investigations. Optical investigations are conducted in an optically accessible high pressure, high temperature chamber using shadowgraphy and OH chemoluminescence detection, thereby capturing both liquid and gaseous penetration as well as combustion areas. Single cylinder investigations are carried out at a 0.4 dm3 research engine in different operating points from low part load to full load. Compared to a serial production piezo injector, base measurements using conventional square injection profiles already show reduced combustion noise at improved NOx-soot trade-off as well as lowered HC and CO emissions. Detailed investigations at part load operating points explore the potential of different continuous rate shaping patterns, while the injector’s high injection pressure capability of up to 2500 bar and its influence on engine performance is tested at full load operation points.

Influence Factors of Energy Consumption in All Cold Outdoor Air Systems

Solar Energy ◽  
2006 ◽  
Author(s):  
Bing Wei ◽  
Li Li ◽  
Jiang Lu ◽  
Luxiang Zong ◽  
Zhiwei Wang
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Influence Factors ◽  
Operation Time ◽  
Dew Point ◽  
Coefficient Of Performance ◽  
Equivalent Weight ◽  
Outdoor Air ◽  
Full Load ◽  
Full Load Operation

Nowadays the safety of the air conditioning systems is paid more attention to. All cold outdoor air systems due to their particular advantages such as credible safety, better indoor air quality, saving more building space and being in favor of the energy conservation in some given conditions [1] are discussed in this paper. The composing of all cold outdoor air system is outlined and the mathematical models of energy consumption evaluation are presented. With an actual example by using the method of equivalent weight full load operation time, the influence factors to the annual primary energy consumptions in all cold outdoor air systems, such as: the dew point temperature, the COP (Coefficient of Performance) of chiller, the equivalent weight full load operation time of chiller and the efficiency of enthalpy exchanger etc. are compared and analyzed. And the optimal application modes for energy conservation of all cold outdoor air systems are proposed. These can be good references for the application of all cold outdoor air systems.

Sign in / Sign up

Export Citation Format

Share Document