Introduction and Performance Prediction of a Nutating-Disk Engine

2004 ◽  
Vol 126 (2) ◽  
pp. 294-299 ◽  
Author(s):  
T. Korakianitis ◽  
L. Meyer ◽  
M. Boruta ◽  
H. E. McCormick
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Engine ◽  
Thermodynamic Cycle ◽  
Simple Cycle ◽  
Specific Power ◽  
Engine Operation ◽  
And Performance ◽  
Stroke Engine

A new type of internal combustion engine and its thermodynamic cycle are introduced. The core of the engine is a nutating nonrotating disk, with the center of its hub mounted in the middle of a Z-shaped shaft. The two ends of the shaft rotate, while the disk nutates. The motion of the disk circumference prescribes a portion of a sphere. A portion of the area of the disk is used for intake and compression, a portion is used to seal against a center casing, and the remaining portion is used for expansion and exhaust. The compressed air is admitted to an external accumulator, and then into an external combustion chamber before it is admitted to the power side of the disk. The accumulator and combustion chamber are kept at constant pressures. The engine has a few analogies with piston-engine operation, but like a gas turbine it has dedicated spaces and devices for compression, burning, and expansion. The thermal efficiency is similar to that of comparably sized simple-cycle gas turbines and piston engines. For the same engine volume and weight, this engine produces less specific power than a simple-cycle gas turbine, but approximately twice the power of a two-stroke engine and four times the power of a four-stroke engine. The engine has advantages in the 10 kW to 200 kW power range. This paper introduces the geometry and thermodynamic model for the engine, presents typical performance curves, and discusses the relative advantages of this engine over its competitors.

Introduction and Performance Prediction of a Nutating-Disk Engine

1999 ◽  
Author(s):  
T. Korakianitis ◽  
L. Meyer ◽  
M. Boruta ◽  
H. E. McCormick
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Engine ◽  
Thermodynamic Cycle ◽  
Rotating Disk ◽  
Simple Cycle ◽  
Specific Power ◽  
Engine Operation ◽  
Stroke Engine

A new type of internal combustion engine and its thermodynamic cycle are introduced. The core of the engine is a nutating non-rotating disk, with the center of its hub mounted in the middle of a Z-shaped shaft. The two ends of the shaft rotate, while the disk nutates. The motion of the disk circumference prescribes a portion of a sphere. A portion of the area of the disk is used for intake and compression, a portion is used to seal against a center casing, and the remaining portion is used for expansion and exhaust. The compressed air is admitted to an external accumulator, and then into an external combustion chamber before it is admitted to the power side of the disk. The accumulator and combustion chamber are kept at constant pressures. The engine has a few analogies with piston-engine operation, but like a gas turbine it has dedicated spaces and devices for compression, burning and expansion. The thermal efficiency is similar to that of comparably-sized simple-cycle gas turbines and piston engines. For the same engine volume and weight, this engine produces less specific power than a simple-cycle gas turbine, but approximately twice the power of a two-stroke engine and four times the power of a four-stroke engine. The engine has advantages in the 10 kW to 200 kW power range. This paper introduces the geometry and thermodynamic model for the engine, presents typical performance curves, and discusses the relative advantages of this engine over its competitors.

Heat-Exchanged Propulsion Gas Turbines: A Candidate for Future Lower SFC and Reduced-Emission Military and Civil Aeroengines

2009 ◽  
Author(s):  
Colin F. McDonald ◽  
Colin Rodgers
Keyword(s):  
Gas Turbines ◽  
High Efficiency ◽  
Pressure Ratio ◽  
Thermodynamic Cycle ◽  
Simple Cycle ◽  
Specific Power ◽  
Operational Experience ◽  
Fuel Cost ◽  
Turbofan Engines ◽  
Fuel Burn

After seven decades of service the evolution of simple cycle propulsion gas turbines continues with emphasis now being placed on reduced fuel burn, lower emissions, and less noise. With compressor and turbine efficiencies near plateauing, and turbine inlet temperatures paced by materials and blade cooling technologies, improvements in SFC, specific power and weight for conventional engines (including small turboprop, and turboshaft engines and larger turbofans) will likely be incremental compared with the past. With retention of the simple cycle both evolutionary and revolutionary approaches are being taken by the aeroengine industry to improve performance, particularly reduced fuel burn in an era of high fuel cost. In this paper a further step is suggested, that is in concert with meeting performance, economic, and environmental goals of future aeroengines, namely the use of a more complex thermodynamic cycle involving recuperation for turboprop and turboshaft engines, and intercooling together with recuperation for higher pressure ratio turbofan engines. The idea of heat exchanged propulsion gas turbines is not new, but the many concepts identified from studies done periodically over the last 65 years, including the few engines that were static tested and one test flown, didn’t find acceptance in an era of low fuel cost and concerns about recuperator integrity and reliability. With today’s very high fuel cost there is current interest in this type of engine because of its potential for low SFC and reduced emissions. In this paper potential applications are summarized and the features of various heat exchanged aeroengine design concepts together with projected performance are presented. Included is a discussion on the various issues that must be resolved before they enter service. A postulated deployment scenario is suggested with engines initially developed to meet military aviation needs, such as recuperated turboprop and turbofan engines for extended range UAV’s, followed by a recuperated turboshaft engine for a helicopter. Operational experience and demonstrated reliability from these would pave the way for high efficiency ICR turbofan engines for military and civil aircraft service sometime after the year 2020.

scholarly journals Gas Turbine Topping Stage Based on Energy Exchangers: Process and Performance

1993 ◽  
Author(s):  
Erwin Zauner ◽  
Yau-Pin Chyou ◽  
Frederic Walraven ◽  
Rolf Althaus
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
Operating Cost ◽  
Combined Cycle ◽  
Specific Power ◽  
Material Strength ◽  
Nox Emissions ◽  
Gas Temperature ◽  
And Performance

Power generation in gas turbines is facing three main challenges today: • Low pollution prescribed by legal requirements. • High efficiency to obtain low operating cost and low CO2 emissions. • High specific power output to obtain low product and installation cost. Unfortunately, some of these requirements are contradictory: high efficiency and specific power force the development towards higher temperatures and pressures which increase NOx emissions and intensify the cooling and material strength problems. A breakthrough can be achieved by applying an energy exchanger as a topping stage. Inherent advantages are the self-cooled cell-rotor which can be exposed to much higher gas temperature than a steady-flow turbine and a very short residence time at peak temperature which keeps NOx emissions under control. The basic idea has been proposed long time ago. Fundamental research has now led to a new energy exchanger concept. Key issues include symmetric pressure-wave processes, partial suppression of flow separation and fluid mixing, as well as quick afterburning in premixed mode. The concept has been proven in a laboratory-scale engine with very promising results. The application of an energy exchanger as a topping stage onto existing gas turbines would increase the efficiency by 17% (relative) and the power by 25%. Since the temperature level in the turbine remains unchanged, the performance improvement can also be fully utilized in combined cycle applications. This process indicates great potentials for developing advanced gas turbine systems as well as for retrofitting existing ones.

Investigation of Different Solar Hybrid Gas Turbines and Exploitation of Rejected Sun Power

2016 ◽  
Author(s):  
C. Kalathakis ◽  
N. Aretakis ◽  
I. Roumeliotis ◽  
A. Alexiou ◽  
K. Mathioudakis
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Fuel Efficiency ◽  
Specific Power ◽  
Fuel Saving ◽  
Power Penalty ◽  
Design Point ◽  
Turbine Performance ◽  
High Irradiation

Solar hybrid gas turbine performance is studied through consideration of four engine configurations: a) single shaft, b) recuperated single-shaft, c) twin-shaft and d) two-spool three-shaft, intercooled, recuperated. For each configuration and for the same design point, the performance is obtained for two hybridization schemes: Fuel only engines Retrofitted for Solar operation (FRS) and engines designed with Solar only operation at the Design Point (SDP). In an attempt to further improve the benefits of hybridization, the concept of a Dual Fluid Receiver for exploiting the rejected solar power, during sunny hours with high irradiation, is demonstrated. Steam is produced by focusing the defocused mirrors of the heliostat field to a second receiver and injected into the combustion chamber. For the cases examined, it can be concluded that FRS engines show better performance than SDP ones, since they exhibit higher thermal fuel efficiency and higher specific power. Concerning the configurations, an annual fuel saving of ∼35% and an annual output reduction, ranging from 4% for the recuperated single-shaft configuration to 9% for the twin shaft configuration compared to the corresponding fuel-only engines is demonstrated. The inclusion of a Dual Fluid Receiver in an FRS engine removes the power penalty while it maintains the fuel saving benefit.

scholarly journals Comprehensive Thermodynamic Analysis of the Humphrey Cycle for Gas Turbines with Pressure Gain Combustion

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3521 ◽  
Author(s):  
Panagiotis Stathopoulos
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Process ◽  
Ideal Gas ◽  
Point Of View ◽  
Pressure Gain Combustion ◽  
Combustion Technology ◽  
Secondary Air ◽  
And Performance ◽  
The Impact

Conventional gas turbines are approaching their efficiency limits and performance gains are becoming increasingly difficult to achieve. Pressure Gain Combustion (PGC) has emerged as a very promising technology in this respect, due to the higher thermal efficiency of the respective ideal gas turbine thermodynamic cycles. Up to date, only very simplified models of open cycle gas turbines with pressure gain combustion have been considered. However, the integration of a fundamentally different combustion technology will be inherently connected with additional losses. Entropy generation in the combustion process, combustor inlet pressure loss (a central issue for pressure gain combustors), and the impact of PGC on the secondary air system (especially blade cooling) are all very important parameters that have been neglected. The current work uses the Humphrey cycle in an attempt to address all these issues in order to provide gas turbine component designers with benchmark efficiency values for individual components of gas turbines with PGC. The analysis concludes with some recommendations for the best strategy to integrate turbine expanders with PGC combustors. This is done from a purely thermodynamic point of view, again with the goal to deliver design benchmark values for a more realistic interpretation of the cycle.

Performance Prediction of Gas Turbine Under Different Strategies Using Low Heating Value Fuel

2013 ◽  
Author(s):  
Edson Batista da Silva ◽  
Marcelo Assato ◽  
Rosiane Cristina de Lima
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Equivalence Ratio ◽  
Safe Operation ◽  
Engine Operation ◽  
Heating Value ◽  
Gasification Process ◽  
Surge Margin ◽  
And Performance ◽  
Industrial Gas Turbine

Usually, the turbogenerators are designed to fire a specific fuel, depending on the project of these engines may be allowed the operation with other kinds of fuel compositions. However, it is necessary a careful evaluation of the operational behavior and performance of them due to conversion, for example, from natural gas to different low heating value fuels. Thus, this work describes strategies used to simulate the performance of a single shaft industrial gas turbine designed to operate with natural gas when firing low heating value fuel, such as biomass fuel from gasification process or blast furnace gas (BFG). Air bled from the compressor and variable compressor geometry have been used as key strategies by this paper. Off-design performance simulations at a variety of ambient temperature conditions are described. It was observed the necessity for recovering the surge margin; both techniques showed good solutions to achieve the same level of safe operation in relation to the original engine. Finally, a flammability limit analysis in terms of the equivalence ratio was done. This analysis has the objective of verifying if the combustor will operate using the low heating value fuel. For the most engine operation cases investigated, the values were inside from minimum and maximum equivalence ratio range.

Assessment of Solar Steam Injection in Gas Turbines

2016 ◽  
Author(s):  
C. Kalathakis ◽  
N. Aretakis ◽  
I. Roumeliotis ◽  
A. Alexiou ◽  
K. Mathioudakis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Fuel Efficiency ◽  
Thermal Power ◽  
Steam Injection ◽  
Power Production ◽  
Engine Operation ◽  
Efficiency Increase ◽  
Solar Receiver ◽  
Steam Production

The concept of solar steam production for injection in a gas turbine combustion chamber is studied for both nominal and part load engine operation. First, a 5MW single shaft engine is considered which is then retrofitted for solar steam injection using either a tower receiver or a parabolic troughs scheme. Next, solar thermal power is used to augment steam production of an already steam injected single shaft engine without any modification of the existing HRSG by placing the solar receiver/evaporator in parallel with the conventional one. For the case examined in this paper, solar steam injection results to an increase of annual power production (∼15%) and annual fuel efficiency (∼6%) compared to the fuel-only engine. It is also shown that the tower receiver scheme has a more stable behavior throughout the year compared to the troughs scheme that has better performance at summer than at winter. In the case of doubling the steam-to-air ratio of an already steam injected gas turbine through the use of a solar evaporator, annual power production and fuel efficiency increase by 5% and 2% respectively.

Siemens SGT-800 Industrial Gas Turbine Enhanced to 50MW: Combustor Design Modifications, Validation and Operation Experience

2013 ◽  
Author(s):  
Daniel Lörstad ◽  
Annika Lindholm ◽  
Jan Pettersson ◽  
Mats Björkman ◽  
Ingvar Hultmark
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Cooling System ◽  
Good Condition ◽  
Combined Cycle ◽  
Combustion Stability ◽  
Combustion System ◽  
Design Work ◽  
Engine Operation ◽  
Cooling Air

Siemens Oil & Gas introduced an enhanced SGT-800 gas turbine during 2010. The new power rating is 50.5MW at a 38.3% electrical efficiency in simple cycle (ISO) and best in class combined-cycle performance of more than 55%, for improved fuel flexibility at low emissions. The updated components in the gas turbine are interchangeable from the existing 47MW rating. The increased power and improved efficiency are mainly obtained by improved compressor airfoil profiles and improved turbine aerodynamics and cooling air layout. The current paper is focused on the design modifications of the combustor parts and the combustion validation and operation experience. The serial cooling system of the annular combustion chamber is improved using aerodynamically shaped liner cooling air inlet and reduced liner rib height to minimize the pressure drop and optimize the cooling layout to improve the life due to engine operation hours. The cold parts of the combustion chamber were redesigned using cast cooling struts where the variable thickness was optimized to maximize the cycle life. Due to fewer thicker vanes of the turbine stage #1, the combustor-turbine interface is accordingly updated to maintain the life requirements due to the upstream effect of the stronger pressure gradient. Minor burner tuning is used which in combination with the previously introduced combustor passive damping results in low emissions for >50% load, which is insensitive to ambient conditions. The combustion system has shown excellent combustion stability properties, such as to rapid load changes and large flame temperature range at high loads, which leads to the possibility of single digit Dry Low Emission (DLE) NOx. The combustion system has also shown insensitivity to fuels of large content of hydrogen, different hydrocarbons, inerts and CO. Also DLE liquid operation shows low emissions for 50–100% load. The first SGT-800 with 50.5MW rating was successfully tested during the Spring 2010 and the expected performance figures were confirmed. The fleet leader has, up to January 2013, accumulated >16000 Equivalent Operation Hours (EOH) and a planned follow up inspection made after 10000 EOH by boroscope of the hot section showed that the combustor was in good condition. This paper presents some details of the design work carried out during the development of the combustor design enhancement and the combustion operation experience from the first units.

scholarly journals Gas Turbines for the Chemical Industry

1957 ◽  
Author(s):  
Z. Stanley Stys
Keyword(s):  
Nitric Acid ◽  
Gas Turbine ◽  
Chemical Industry ◽  
Gas Turbines ◽  
Operating Experience ◽  
And Performance ◽  
Design Construction

Application of the gas turbine in nitric-acid plants appears attractive. Several of these units have been installed recently in this country and performance and operating experience already have been gained. Design, construction, and layout of “package” units for this particular process are described.

Bearing Housing Design for Vibration Control, Using Tilting Pad Bearings Instead of Lemon-Bore Type on a Gas Turbine

2020 ◽  
Author(s):  
Chippa Anil ◽  
Aparna Satheesh ◽  
Babu Santhanagopalakrishnan ◽  
Marcin Bielecki
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Structural Integrity ◽  
Plane Surface ◽  
Rotor Dynamics ◽  
Turbine Rotor ◽  
Outer Diameter ◽  
Housing Design ◽  
Tilting Pad ◽  
And Performance

Abstract Heavy duty gas turbines are usually equipped with hydrodynamic bearings which are either lemon-bore or tilting pad type. Baker Hughes legacy gas turbines use these two types of bearings, and its selection is based on 1) considering pros & cons from Rotor dynamics, 2) bearing performance, 3) bearing housing stiffness, 4) vibration detection & control. Non-contact probes are used to monitor the vibrations of rotor. Majority of legacy gas turbines are not equipped with these probes. Due to this fact, over the years it resulted in non-detection of dynamics & vibration issue, which caused frequent bearing replacement. As the increase in industry demand to apply and measure vibrations using non-contact probes on bearings, an effort was made by Baker Hughes to implement these on existing fleet units. Also, in order to increase rotor dynamics stability of low-pressure rotor, to improve bearing life and performance, effort was made to replace lemon-bore bearings with tilting pad. This paper demonstrates efforts made to design the titling pad which would fit within envelop of already available bearing housing. Bearing/shaft clearance, bearing performance, modification of bearing retainer clearances are the mandatory tasks which would be dealt in this study. The swap of bearing type, and its effect on whole gas turbine rotor dynamic stability, checking the frequency crossovers with Campbell diagram would also be dealt in this paper. This paper also focuses on assessment on oil passage routing, temperature & proximity probe instrumentation routing design. Re-design is performed by analyzing various configuration, assessing different sensitivity studies & validation of modified bearing housing from structural integrity, ultimate load capability, & split plane oil leakage retention and its comparison with baseline are most important aspects of finalization of this change, which will be showcased in this paper. Instrumentation routing was a critical task when the considering bearing replacement from lemon-bore to tilting pad. As lemon-bore type bearings just have an elliptical inner surface, it’s quite easy to install the thermocouples into a simple hole. But as replacement has tilting pads, the challenge is to instrument the pads without effecting their movement and functionality. Such best practices are also dealt in this paper. Comparison of tilting-pad with lemon-bore, considering the fixed shaft diameter, the retainer outer diameter of tilting pad is higher than lemon-bore. This effect has a change in bearing seat on bearing housing, thereby reducing the effective stiffness of the housing, and the reduced split plane surface. To tackle this situation, several sensitivities were executed, by re-modifying the bolts and bolt holes on the existing housing, without modifying the housing envelop.

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