High Capacity and High Efficiency Multi-Stage Air Intake System

Author(s):  
Alan Hashem ◽  
Dani Fadda ◽  
Kenneth J. Fewel

An advanced three stage filtration/separation air intake system (Compact II) is introduced in this paper. The system was developed to meet the current and expected future market demands for gas turbine combustion air treatment in a marine environment. Developing and testing of the Compact II are subjects of this paper.

Author(s):  
Roger Yee ◽  
Alan Oswald

A new generation of auxiliary ships to enter the U.S. Navy (USN) fleet is the AOE-6 SUPPLY CLASS. These fast combat support ships conduct operations at sea as part of a Carrier Battle group to provide oil, aviation fuel, and ammunition to the carrier and her escorts. The SUPPLY CLASS is the first ship in the entire USN fleet to use a combined gas turbine and diesel generator cooling air intake system to cool its respective engine modules. The cooling air intake was designed this way to save on costs. As the ships in this class continued with operations and problems of insufficient supply of cooling air for the gas turbines modules started surfacing, the entire intake system required investigation and analysis. Since the gas turbines and diesel generators share a common cooling air trunk, they were competing for air. This paper will outline the tests that were performed to determine the problems, the recommended solutions, and the lessons learned from the investigations.


Author(s):  
V. L. Blinov ◽  
I. S. Zubkov ◽  
Yu. M. Brodov ◽  
B. E. Murmanskij

THE PURPOSE. To study the issues of air intake system’s performance as the part of the gas turbines. To estimate the possibility of modeling different performance factors of air intake systems with numerical simulation methods. To develop the recommendations of setting up the grid and the numerical models for researches in air intake system’s performance and assessing the technical condition of elements of it. METHODS. The main method, which was used during the whole study, is computational fluid dynamics with usage of CAE-systems.RESULTS. During the study the recommendations for setting up the numerical model were developed. Such factors as grid model parameters, roughness scale, pressure drop in elements of air intake system and some more were investigated. The method for heat exchanger’s performance simulation were created for modeling the air temperature raising. CONCLUSION. The air intake system’s performance analysis becomes one of the actual topics for research because of the high demands of gas turbines to air, which is used in its annulus. The main part of these researches is in analysis of dangerous regimes of work (e.g. the icing process of annulus elements) or in assessing technical condition of air intake systems and its influence to the gas turbine as a whole. The developed method of numerical simulation allows to get the adequate results with low requirements for computational resources. Also this method allows to model the heat exchanger performance and study its defects’ influence to the performance of air intake system as a whole. 


Author(s):  
Yunfeng Jin ◽  
Chao Liu ◽  
Xin Tian ◽  
Haizhou Huang ◽  
Gaofeng Deng ◽  
...  

Due to the complex and harsh environmental factors, the useful life of the filter in the gas turbine air intake system is usually less than its design life. When the filter is seriously degraded, the power and thermal efficiency of the gas turbine will decrease obviously due to the increase of inlet pressure loss. For evaluating the health condition of filters in the air intake system, this work forms a filter pressure loss model with the defined health index for the filter and five external environmental and control factors. By integrating the gas path component model, the combined model is applied in a real data set and the results show that (i) the proposed health index is efficient in representing the degradation state of the filter, (ii) the influencing factors on the pressure loss are successfully decoupled and their contributions on the pressure are quantitatively estimated, and (iii) the integrated model of filter pressure loss and gas path component can be used to better estimate the deterioration states of the filter as well as the gas turbine performance.


Author(s):  
Zhongyi Wang ◽  
Fei Li ◽  
Zhengheng Zhao ◽  
Changlong Yuan

An anti-icing device is designed for resisting the ice accretion occurring in the air intake system of hovercraft gas turbine, which may affect its normal operation. The anti-icing purpose was achieved by mixing hot bleed air from the engine compressor and cold intake ambient air. Some research on the bleed air heating system was done by using 3D numerical simulation method. Under the set parameter of bleed air, the ambient temperature range for different bleed air flow was obtained and the corresponding anti-icing effect was also simulated. When the ambient temperature changed, the influence of anti-icing device’s working on total pressure loss of air intake system and the distributing condition of the compressor inlet surface velocity nonuniformity were investigated, and their changing law under different icing condition was obtained. The researching results provide theoretical and practical guidance and support for ships equipped with gas turbine when sailing in low temperature region.


Author(s):  
Stian Madsen ◽  
Jørn Watvedt ◽  
Lars E. Bakken

Optimized operation of gas turbines is discussed for a fleet of eleven LM2500PE engines at a Statoil North Sea offshore field in Norway. Three engines are generator drivers while eight engines are compressor drivers. Several of the compressor drive engines run at peak load (T5.4 control), hence production rate is limited by the available power from these engines. The majority of the engines discussed run continuously without redundancy, hence gas turbine uptime is critical for the field’s production and economy. The performance and operational experience with upgraded inlet air filter systems, as well as successful operation at longer maintenance intervals and higher average engine performance are described. For North Sea operation, a key property of the filter system is the ability to handle high humidity and high salt-content, typical of the harsh environment in these waters. The upgraded filter system analyzed in this paper is a 2-stage system (vane separator stage upstream of the high-efficiency filter stage), which is a simplified design versus the old traditional 3-stage systems (louvre upstream and vane separator downstream of the filter stage). These 2-stage systems rely on an efficient upstream vane separator to remove the vast majority of water from the airflow before it reaches the high-efficiency filters. The high-efficiency filters are specially designed to withstand moisture. The effectiveness and contribution of each component in the filtration system are described. Extensive testing of both new and used filter elements, of different filter grade and operated at different intervals, has been performed in a filter test rig facility onshore. Extensive testing of used filters has also been performed at the filter OEM, where filter efficiency is measured as well as destructive testing and analysis of the filter layers. The effect of an optimized air intake filter system for the subject engines, is longer operating intervals, higher power availability and lower engine deterioration. The operating intervals are now extended to six months (4,000 hours), from initially two months (1,500 hours, early 1990s) then four months (3,000 hours, mid 2000s). The HPC efficiency deterioration is reduced by some 3% related to intake filter system, of a total of over 6% in efficiency deterioration over each 6-month operating period.


Author(s):  
Seyed M Ghoreyshi ◽  
Meinhard T Schobeiri

The Ultra-High Efficiency Gas Turbine Engine (UHEGT) was introduced in our previous studies. In UHEGT, the combustion process is no longer contained in isolation between the compressor and turbine. It is rather distributed in multiple stages and integrated within the high-pressure turbine stator rows. Compared to the current most advanced conventional gas turbines, UHEGT considerably improves the efficiency and output power of the engine while reducing its emissions and size. In this study, a six-stage UHEGT turbine with three stages of stator internal combustion is designed and analyzed. The design represents a single spool turboshaft system for power generation using gaseous fuels. The preliminary flow path for each turbine stage is designed by the meanline approach and modified using Computational Fluid Dynamics (CFD). Unsteady CFD calculation (via commercial software ANSYS CFX) is used to simulate and optimize the flow and combustion process through high-pressure turbine stages. The results show a base thermal efficiency of above 45% is achieved. It shows a successful integration of the multi-stage combustion process into the high-pressure turbine stages and a highly uniform temperature distribution at the inlet of each rotor row. High temperatures in some areas on the stator blade surfaces are controlled using indexing of fuel injectors and stator blades.


Author(s):  
Stephen D. Hiner

An optimised inlet air system design is an important factor in the gas turbine (GT) industry. Optimising the design of the air intake system is an increasingly challenging process as both the layout complexity and range of features that can be included in the intake system expands. These may include a combination of insect or trash screens, weather protection and filtration systems, silencers, anti-icing systems, ventilation system off takes and inlet heating or cooling systems for power augmentation. Poor designs can result in inefficient use of these components as well as losses in engine performance due to excessive pressure losses or distortion in the flow entering the gas turbine. High flow distortion, velocity, pressure or temperature, can induce compressor surge and high acromechanical stresses in compressor blades and vanes. In extreme cases this may result in blade or vane failures. Computational Fluid Dynamics (CFD) analysis is a powerful tool for visualisation of the predicted flow through a hypothetical air inlet system prior to manufacture. The CFD output plots include flow streamlines and contours, of pressure, velocity or temperature, at any plane in the model. These enable pressure losses, flow distortion issues, potential recirculation areas and high local velocities within the system to be reviewed. This allows optimisation of the installation design to minimise system pressure loss and flow distortion, both through the components and at the engine interface. This paper, with reference to case studies of gas turbine applications, highlights the impact that CFD analysis can have on the design of intake systems to ensure that the best overall performance is obtained. The process of developing the CFD geometry and how significant features of an installation are modeled is outlined. Environmental and operational conditions, such as cross winds can impact the flow through an intake system; therefore, incorporation of such factors into the model boundary conditions are covered. Typical output metrics from the CFD analysis are shown from selected case studies; total pressure drop and flow distortion at the interface plane between the intake system and gas turbine. The importance of experienced interpretation of the CFD output to define potential intake design modifications to improve system performance is highlighted. In specific cases model testing has been carried out to validate CFD results. Case study examples are used to show the improvements made in air intake performance that contribute to increased operational efficiency of the gas turbine application.


Author(s):  
N.S. Mustafa ◽  
N.H.A. Ngadiman ◽  
M.A. Abas ◽  
M.Y. Noordin

Fuel price crisis has caused people to demand a car that is having a low fuel consumption without compromising the engine performance. Designing a naturally aspirated engine which can enhance engine performance and fuel efficiency requires optimisation processes on air intake system components. Hence, this study intends to carry out the optimisation process on the air intake system and airbox geometry. The parameters that have high influence on the design of an airbox geometry was determined by using AVL Boost software which simulated the automobile engine. The optimisation of the parameters was done by using Design Expert which adopted the Box-Behnken analysis technique. The result that was obtained from the study are optimised diameter of inlet/snorkel, volume of airbox, diameter of throttle body and length of intake runner are 81.07 mm, 1.04 L, 44.63 mm and 425 mm, respectively. By using these parameters values, the maximum engine performance and minimum fuel consumption are 93.3732 Nm and 21.3695×10-4 kg/s, respectively. This study has fully accomplished its aim to determine the significant parameters that influenced the performance of airbox and optimised the parameters so that a high engine performance and fuel efficiency can be produced. The success of this study can contribute to a better design of an airbox.


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