scholarly journals Low-Pressure Turbine Cooling Systems

Encyclopedia ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 893-904
Author(s):  
Krzysztof Marzec
Keyword(s):  
Low Pressure ◽  
Engine Fuel ◽  
Cooling Systems ◽  
Turbine Cooling ◽  
Low Pressure Turbine ◽  
Blade Cooling ◽  
Air Supply ◽  
Turbine Casing ◽  
Radial Gap ◽  
Cooling Air

Modern low-pressure turbine engines are equipped with casings impingement cooling systems. Those systems (called Active Clearance Control) are composed of an array of air nozzles, which are directed to strike turbine casing to absorb generated heat. As a result, the casing starts to shrink, reducing the radial gap between the sealing and rotating tip of the blade. Cooling air is delivered to the nozzles through distribution channels and collector boxes, which are connected to the main air supply duct. The application of low-pressure turbine cooling systems increases its efficiency and reduces engine fuel consumption.

Case Study 1.2: Turning of Low Pressure Turbine Casing

2017 ◽  
pp. 25-38
Author(s):  
Oscar Gonzalo ◽  
Jose Mari Seara ◽  
Eneko Olabarrieta ◽  
Mikel Esparta ◽  
Iker Zamakona ◽  
...  
Keyword(s):  
Low Pressure ◽  
Low Pressure Turbine ◽  
Turbine Casing

scholarly journals Aerothermal Analysis of a Turbine Casing Impingement Cooling System

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Riccardo Da Soghe ◽  
Bruno Facchini ◽  
Mirko Micio ◽  
Antonio Andreini
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Cooling System ◽  
Control Valve ◽  
Impinging Jets ◽  
Present System ◽  
Air Supply ◽  
Supply Pipe ◽  
Turbine Casing ◽  
Cooling Air

Heat transfer and pressure drop for a representative part of a turbine active cooling system were numerically investigated by means of an in-house code. This code has been developed in the framework of an internal research program and has been validated by experiments and CFD. The analysed system represents the classical open bird cage arrangement that consists of an air supply pipe with a control valve and the present system with a collector box and pipes, which distribute cooling air in circumferential direction of the casing. The cooling air leaves the ACC system through small holes at the bottom of the tubes. These tubes extend at about 180° around the casing and may involve a huge number of impinging holes; as a consequence, the impinging jets mass flow rate may vary considerably along the feeding manifold with a direct impact on the achievable heat transfer levels. This study focuses on the performance, in terms of heat transfer coefficient and pressure drop, of several impinging tube geometries. As a result of this analysis, several design solutions have been compared and discussed.

Heat Transfer and Pressure Drop Analysis of a Turbine Casing Impingement Cooling System

2012 ◽  
Author(s):  
Riccardo Da Soghe ◽  
Bruno Facchini ◽  
Mirko Micio ◽  
Daniele Coutandin
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Cooling System ◽  
Control Valve ◽  
Impinging Jets ◽  
Present System ◽  
Air Supply ◽  
Supply Pipe ◽  
Turbine Casing ◽  
Cooling Air

Heat transfer and discharge coefficient behaviour for a representative part of a turbine active cooling system were numerically investigated by means of an in-house code. This code has been developed in the framework of an internal research program and has been validated by experiments and CFD. The analysed system represents the classical open bird cage arrangement that consists of an air supply pipe with a control valve and the present system with a collector box and pipes, which distribute cooling air in circumferential direction of the casing. The cooling air leaves the ACC system through small holes at the bottom of the tubes. These tubes extend at about 180° around the casing and may involve a huge number of impinging holes; as a consequence, the impinging jets mass flow rate may vary considerably along the feeding manifold with a direct impact on the achievable heat transfer levels. This study focuses on the performance, in terms of heat transfer coefficient and pressure drop, of several impinging tube geometries. As a result of this analysis, several design solutions have been compared and discussed.

The Application of CFD to Underpin the Design of Gas Turbine Pre-Swirl Systems

2006 ◽  
Author(s):  
G. D. Snowsill ◽  
C. Young
Keyword(s):  
Gas Turbine ◽  
Computation Time ◽  
Computational Time ◽  
Computationally Efficient ◽  
Cooling Systems ◽  
Turbine Cooling ◽  
Secondary Systems ◽  
Set Up ◽  
Cooling Air ◽  
The Impact

The technique of pre-swirling cooling air to reduce its relative total temperature, as felt by rotating components, is well established. It is important to optimise the design of such systems in order to achieve maximum cooling effectiveness and to minimise the impact on cycle efficiency. Traditionally, these cooling systems have been developed by a combination of experimental investigation and careful evolution. However, more recently it has become practical to apply CFD to such problems. The nature of gas turbine cooling systems generally mandates the presence of discrete features on both static and rotating components, so that a fully rigorous analysis would need to be both 3D and unsteady, with the sub-domains adjacent to static and rotating surfaces solved in an appropriate frame of reference, together with a suitable interfacing procedure to communicate the evolving solution between each sub-domain. Such analyses are challenging for current CFD codes, both in terms of computation time and numerical stability. The present work explores the various options that are available to make such computations more practical and hence more accessible to the secondary systems modelling community. Significant reductions in set-up time can be achieved by adopting unstructured calculational meshes, although this may be at the expense of some loss of accuracy and increase in computational time relative to structured meshes. In the present work, an attempt has been made to quantify the effect of these choices. Depending on the configuration of the system under investigation, it may be permissible to ignore the unsteady interactions and to model the system using the more computationally efficient multiple reference frame (MRF) approach. Guidelines are proposed for assessing the likely impact of these simplifications on the results obtained.

Cracks on the Roots of Turbine Blades of the Low-Pressure Turbine in a Steam Power Plant

2015 ◽  
Vol 52 (4) ◽  
pp. 214-225 ◽  
Author(s):  
E. Plesiutschnig ◽  
R. Vallant ◽  
G. Stöfan ◽  
C. Sommitsch ◽  
M. Mayr ◽  
...  
Keyword(s):  
Power Plant ◽  
Turbine Blades ◽  
Low Pressure ◽  
Steam Power ◽  
Steam Power Plant ◽  
Low Pressure Turbine

Low-pressure turbine disc fi rtree slots’ life and reliability enhancement by ultrasonic surface hardening

2020 ◽  
pp. 491-495
Author(s):  
A.M. Tomashevich ◽  
G.G. Shirvan’yants ◽  
D.A. Teryaev
Keyword(s):  
Residual Stress ◽  
Low Pressure ◽  
Fatigue Tests ◽  
Compression Stress ◽  
Cycle Basis ◽  
Low Pressure Turbine ◽  
Working Stress ◽  
Turbine Disc ◽  
Axial Residual Stress ◽  
Reliability Enhancement

The possibility of life and reliability enhancing of AL-31F low pressure turbine disc’s fir-tree slots by ultrasonic hardening is considered. Having disc’s material properties studied, working stress derivation is executed which was further used for following comparative fatigue tests. Also, Davidenkov method residual stress analysis is carried out which showed 95.3 % change to compression stress for circumferential residual stress and 80.9 % change to compression stress for axial residual stress which proves possibility of fir-tree slots’ life and reliability enhancement by ultrasonic hardening. Comparative fatigue tests with N = 4•10 5 cycles basis showed that the hardened samples standing out the cycle basis during higher oscillatory amplitudes (and, thus, affecting loads) than the non-hardened basic ones.

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