Thermodynamic Analysis of “Inter-Turbine” and “Intra-Turbine” Reheat for Marine Gas Turbines

2004 ◽  
Author(s):  
Knox T. Millsaps ◽  
Bruce Rodman
Keyword(s):  
Path Analysis ◽  
Fuel Consumption ◽  
Power Density ◽  
Thermodynamic Analysis ◽  
Constant Temperature ◽  
Gas Turbines ◽  
Component Technology ◽  
Primary Flow ◽  
Total Fuel Consumption ◽  
Mission Profile

This paper presents thermodynamic analyses of two types of reheat combustion cycles in gas turbines and provides an evaluation of their usefulness in marine power and propulsion applications. Specifically, baseline cycles, using components of various technology levels, were compared to cycles with single-stage reheat (inter-turbine reheat), and continuous or constant temperature reheat (intra-turbine reheat). the results of this primary flow path analysis show that reheat can greatly increase the power density, while reducing the total fuel consumption over a standard warship mission profile. These trends are strongest at lower technology levels, but are also present at higher component technology levels.

A Variable-Geometry Power Turbine for Marine Gas Turbines

1989 ◽  
Author(s):  
Karl W. Karstensen ◽  
Jesse O. Wiggins
Keyword(s):  
Fuel Consumption ◽  
Gas Turbines ◽  
Part Load ◽  
Surface Ship ◽  
Marine Propulsion ◽  
Medium Speed ◽  
Power Turbine ◽  
Wide Range ◽  
Electrical Generator ◽  
Variable Power

Gas turbines have been accepted in naval surface ship applications, and considerable effort has been made to improve their fuel consumption, particularly at part-load operation. This is an important parameter for shipboard engines because both propulsion and electrical-generator engines spend most of their lives operating at off-design power. An effective way to improve part-load efficiency of recuperated gas turbines is by using a variable power turbine nozzle. This paper discusses the successful use of variable power turbine nozzles in several applications in a family of engines developed for vehicular, industrial, and marine use. These engines incorporate a variable power turbine nozzle and primary surface recuperator to yield specific fuel consumption that rivals that of medium speed diesels. The paper concentrates on the experience with the variable nozzle, tracing its derivation from an existing fixed vane nozzle and its use across a wide range of engine sizes and applications. Emphasis is placed on its potential in marine propulsion and auxiliary gas turbines.

Ship Component in Hull Optimization

2005 ◽  
Vol 39 (2) ◽  
pp. 39-46 ◽  
Author(s):  
Kent Davey
Keyword(s):  
Gas Turbines ◽  
Optimized Design ◽  
Power Train ◽  
Load Demand ◽  
Hull Optimization ◽  
Size Number ◽  
Component Identification ◽  
Electric Ship ◽  
Mission Profile ◽  
System Volume

This document outlines an optimization to define the size of the components in the power train of an electric ship, specifically one appropriate for an 80 MW Destroyer. The objective is to minimize the volume of the system, including the fuel. The size, number and speed of the gas turbines, the electric generators, and the power electronics are considered as unknowns in the analysis. At the heart of the procedure is the power mission profile. The gas turbine is by far the most important component in terms of influence on system volume. Integral to its selection is the specific fuel consumption as a function of power and turbine size. The proposed procedure outlines a nested optimization to define both the best spread of turbines as well as the proper scheduling with load demand. Including fuel in the system volume is the key to meaningful component identification. The optimized design has a system volume 603.5 m3 smaller than the base configuration, assuming both systems employ load scheduling among turbines. An optimized design can save as much as 600 m3.

Rolls Royce/Allison 501-K Gas Turbine Anti-Fouling Compressor Coatings Evaluation

2002 ◽  
Author(s):  
Daniel E. Caguiat
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Gas Turbines ◽  
Performance Degradation ◽  
Specific Fuel Consumption ◽  
Inlet Temperature ◽  
Test Results ◽  
Turbine Inlet ◽  
Compressor Performance ◽  
Compressor Efficiency

The Naval Surface Warfare Center, Carderock Division (NSWCCD) Gas Turbine Emerging Technologies Code 9334 was tasked by NSWCCD Shipboard Energy Office Code 859 to research and evaluate fouling resistant compressor coatings for Rolls Royce Allison 501-K Series gas turbines. The objective of these tests was to investigate the feasibility of reducing the rate of compressor fouling degradation and associated rate of specific fuel consumption (SFC) increase through the application of anti-fouling coatings. Code 9334 conducted a market investigation and selected coatings that best fit the test objective. The coatings selected were Sermalon for compressor stages 1 and 2 and Sermaflow S4000 for the remaining 12 compressor stages. Both coatings are manufactured by Sermatech International, are intended to substantially decrease blade surface roughness, have inert top layers, and contain an anti-corrosive aluminum-ceramic base coat. Sermalon contains a Polytetrafluoroethylene (PTFE) topcoat, a substance similar to Teflon, for added fouling resistance. Tests were conducted at the Philadelphia Land Based Engineering Site (LBES). Testing was first performed on the existing LBES 501-K17 gas turbine, which had a non-coated compressor. The compressor was then replaced by a coated compressor and the test was repeated. The test plan consisted of injecting a known amount of salt solution into the gas turbine inlet while gathering compressor performance degradation and fuel economy data for 0, 500, 1000, and 1250 KW generator load levels. This method facilitated a direct comparison of compressor degradation trends for the coated and non-coated compressors operating with the same turbine section, thereby reducing the number of variables involved. The collected data for turbine inlet, temperature, compressor efficiency, and fuel consumption were plotted as a percentage of the baseline conditions for each compressor. The results of each plot show a decrease in the rates of compressor degradation and SFC increase for the coated compressor compared to the non-coated compressor. Overall test results show that it is feasible to utilize anti-fouling compressor coatings to reduce the rate of specific fuel consumption increase associated with compressor performance degradation.

Marine Gas Turbine Performance Model for More Electric Ships

2011 ◽  
Author(s):  
George M. Koutsothanasis ◽  
Anestis I. Kalfas ◽  
Georgios Doulgeris
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Diesel Engines ◽  
Gas Turbines ◽  
Electric Propulsion ◽  
Operating Conditions ◽  
Prime Mover ◽  
Creep Life ◽  
Hull Fouling ◽  
Turbine Performance

This paper presents the benefits of the more electric vessels powered by hybrid engines and investigates the suitability of a particular prime-mover for a specific ship type using a simulation environment which can approach the actual operating conditions. The performance of a mega yacht (70m), powered by two 4.5MW recuperated gas turbines is examined in different voyage scenarios. The analysis is accomplished for a variety of weather and hull fouling conditions using a marine gas turbine performance software which is constituted by six modules based on analytical methods. In the present study, the marine simulation model is used to predict the fuel consumption and emission levels for various conditions of sea state, ambient and sea temperatures and hull fouling profiles. In addition, using the aforementioned parameters, the variation of engine and propeller efficiency can be estimated. Finally, the software is coupled to a creep life prediction tool, able to calculate the consumption of creep life of the high pressure turbine blading for the predefined missions. The results of the performance analysis show that a mega yacht powered by gas turbines can have comparable fuel consumption with the same vessel powered by high speed Diesel engines in the range of 10MW. In such Integrated Full Electric Propulsion (IFEP) environment the gas turbine provides a comprehensive candidate as a prime mover, mainly due to its compactness being highly valued in such application and its eco-friendly operation. The simulation of different voyage cases shows that cleaning the hull of the vessel, the fuel consumption reduces up to 16%. The benefit of the clean hull becomes even greater when adverse weather condition is considered. Additionally, the specific mega yacht when powered by two 4.2MW Diesel engines has a cruising speed of 15 knots with an average fuel consumption of 10.5 [tonne/day]. The same ship powered by two 4.5MW gas turbines has a cruising speed of 22 knots which means that a journey can be completed 31.8% faster, which reduces impressively the total steaming time. However the gas turbine powered yacht consumes 9 [tonne/day] more fuel. Considering the above, Gas Turbine looks to be the only solution which fulfills the next generation sophisticated high powered ship engine requirements.

A methodology for identifying the most suitable measurements for engine level and component level gas path diagnostics of a micro gas turbine

2021 ◽  
pp. 095440622110303
Author(s):  
SS Talebi ◽  
AM Tousi ◽  
A Madadi ◽  
M Kiaee
Keyword(s):  
Path Analysis ◽  
Gas Turbine ◽  
Smart Grids ◽  
Gas Turbines ◽  
Complex Dynamics ◽  
Gas Temperature ◽  
Component Level ◽  
Part Load ◽  
Micro Gas Turbine ◽  
Process Gas

Recently, the utilization of micro gas turbines in smart grids are rising that makes the part-load operation principal situation of the engine service. This leads to faster life consumption that increases the importance of the diagnostics process. Gas path analysis is an effective method for gas turbine diagnostics. Complex dynamics of gas turbine induces challenging conditions to perform applicable gas path analysis. This study aims to facilitate MGT gas path diagnostics through reducing the number of monitoring parameters and preparation a pattern for engine level and component level health assessment in both full and part load operation of a recuperated micro gas turbine. To attain this goal a model is proposed to simulate MGT off-design performance which is validated against experimental data in healthy and degraded operation modes. Fouling in compressor, turbine and recuperator and erosion in compressor and turbine as the most common degradations in the gas turbine are considered. The fault simulation is performed by changing the health parameters of gas path components. According to the result investigation, a matrix comprises deviation contours of four parameters, Power, fuel flow, compressor discharge pressure, and exhaust gas temperature is presented and analyzed. The analysis shows that monitoring these parameters makes it possible to perform engine level and component level diagnostics through evaluating a binary code (generated by mentioned parameter variations) against the fault effects pattern in different load fractions and fault severities. The simulation also showed that the most power drop occurred under the compressor fouling by about 8.7% while the most reduction in thermal efficiency is observed under recuperator fouling by about 7.84%. Furthermore, the investigation showed the maximum decrease in the surge margin induced by the compressor fouling during the lower part-load operation by about 45.7% while in the higher loads created by the turbine fouling by about 14%.

scholarly journals Gears Galore!

2013 ◽  
Vol 135 (04) ◽  
pp. 51-54 ◽  
Author(s):  
Lee S. Langston
Keyword(s):  
Fuel Consumption ◽  
Gas Turbines ◽  
Historical Analysis ◽  
Jet Engines ◽  
Efficient Operation ◽  
Jet Engine ◽  
The Status ◽  
The 1960S ◽  
A Company ◽  
Bypass Ratio

This paper presents a review of gas turbines and Honeywell, a company based in Phoenix, history. The article through the review and historical analysis intends to provide perspective on the status of geared fan engines. The addition of a fan to a jet engine, first proposed by Frank Whittle, one of the inventors of the jet engine, increases thrust and reduces fuel consumption. Pratt & Whitney and Rolls Royce were the first to develop a dual spool engine for more efficient operation over a range of flight conditions. Work started on the geared fan TFE731 at the Garrett AiResearch Phoenix Division in 1968. The TFE731 gearbox resulted in a gear reduction of 1.8:1, to power the fan for a 2.5 bypass ratio, which was very high for the 1960s. Honeywell also has another geared turbofan engine, the ALF502. It was developed by AVCO Lycoming in Stratford, Connecticut, and has a 6000–7000 lbt thrust range. Honeywell’s successful 45-year record of producing geared fan small gas turbines gives promise of a bright future for geared fans on large commercial jet engines, providing lower fuel consumption and less noise.

scholarly journals First law thermodynamic analysis of the recuperated humphrey cycle for gas turbines with pressure gain combustion

Energy ◽  
2020 ◽  
Vol 200 ◽  
pp. 117492
Author(s):  
Panagiotis Stathopoulos ◽  
Tim Rähse ◽  
Johann Vinkeloe ◽  
Neda Djordjevic
Keyword(s):  
Thermodynamic Analysis ◽  
Gas Turbines ◽  
Pressure Gain Combustion
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