Gas Turbines Versus Steam Reliability Analysis for a Warship Propulsion Plant

Author(s):  
D. H. Benn

Methods of mathematical analysis are reviewed for defining and numerically computing the reliability of warship propulsion systems. Experimental analysis is made of a twin-screw all-gas-turbine plant design for a small warship and the results are compared with computed figures previously published for a geared-steam-turbine plant. It is apparent that relatively simple arrangement of components in subsystems is an inherent advantage of the gas turbine plant from the reliability standpoint and that this type of plant has a potential for high reliability. The analysis was made possible by the availability of component MTBF figures taken from past experience. It is hoped that this will encourage users of marine propulsion equipment to compile and present additional reliability statistics and possibly complete reliability analyses of propulsion plants currently in service.

Author(s):  
K. Takeo ◽  
Y. Shimura

A new gas turbine, the IM5000, which has changed the image of a gas turbine plant in view of specific size and efficiency, has been developed. In 1980, Ishikawajima-Harima Heavy Industries Co., Ltd., completed the lineup of aircraft-derivative gas turbines ranging from 15,000 to 50,000 hp when the company developed two new models in the 20,000 to 25,000 hp class, the IM2000 and the IM2500. To establish high reliability of the power turbine, an extensive investigation of the rotor assembly was completed. Engine test runs were conducted to confirm blade vibratory stresses through the whole operating range. The stress levels thus obtained revealed far below the critical limit and no detrimental resonance would be expected. The same attempt was adopted on the IM2500 power turbine which was developed in 1980. Through these two engine operations, the measuring method of blade vibratory stresses by means of strain gauges was established. Besides analyses of the rotating parts, analyses and experimental testing have been carried out on the stationary parts.


Author(s):  
R. Yadav ◽  
P. Sreedhar Yadav

The major challenges before the design engineers of a gas turbine plant and its variants are the enhancement of power output, substantial reduction in NOx emission and improvement in plant thermal efficiency. There are various possibilities to achieve these objectives and humid air gas turbine cycle power plant is one of them. The present study deals with the thermodynamic study of humid air gas turbine cycle power plants based on first law. Using the modeling and governing equations, the parametric study has been carried out. The results obtained will be helpful in designing the humid air gas turbines, which are used as peaking units. The comparison of performance of humid air gas turbine cycle shows that it is superior to basic gas turbine cycle but inferior and more complex to steam injected cycle.


Author(s):  
G. E. Marin ◽  
B. M. Osipov ◽  
A. R. Akhmetshin

THE PURPOSE. The study is aimed at studying the effect of fuel gases of various component composition on the environmental performance of the GE 6FA gas turbine unit. Consider using hydrogen as primary sweat to minimize emissions and improve performance of the GE 6FA gas turbine. METHODS. To achieve this goal, the ASGRET (Automated system for gas-dynamic calculations of power turbomachines) software package was used. RESULTS. The article discusses promising directions for the utilization of CO2 using highly efficient technologies with further use or disposal. A mathematical model of a GE 6FA gas turbine unit, diagrams of changes in the main characteristics and the composition of emissions when operating on various types of fuel, including hydrogen, are presented. CONCLUSION. The studies carried out show that a change in the component composition of the gas affects the energy characteristics of the engine. The method for determining the quantitative composition of COx, NOx, SOx in the exhaust gases of a gas turbine plant is presented. The transition to the reserve fuel kerosene leads to an increase in the amount of emissions, which must be taken into account when designing systems for capturing harmful emissions with a dual-fuel fuel gas supply system. The use of hydrogen as a fuel for gas turbines allows to reduce not only the cost of fuel preparation, but also to minimize emissions and improve the performance of the gas turbine plant.


2000 ◽  
Vol 123 (2) ◽  
pp. 265-270 ◽  
Author(s):  
E. A. Khodak ◽  
G. A. Romakhova

At present high temperature, internally cooled gas turbines form the basis for the development of highly efficient plants for utility and industrial markets. Minimizing irreversibility of processes in all components of a gas turbine plant leads to greater plant efficiency. Turbine cooling, like all real processes, is an irreversible process and results in lost opportunity for producing work. Traditional tools based on the first and second laws of thermodynamics enable performance parameters of a plant to be evaluated, but they give no way of separating the losses due to cooling from the overall losses. This limitation arises from the fact that the two processes, expansion and cooling, go on simultaneously in the turbine. Part of the cooling losses are conventionally attributed to the turbine losses. This study was intended for the direct determination of lost work due to cooling. To this end, a cooled gas turbine plant has been treated as a work-producing thermodynamic system consisting of two systems that exchange heat with one another. The concepts of availability and exergy have been used in the analysis of such a system. The proposed approach is applicable to gas turbines with various types of cooling: open-air, closed-steam, and open-steam cooling. The open-air cooling technology has found the most wide application in current gas turbines. Using this type of cooling as an example, the potential of the developed method is shown. Losses and destructions of exergy in the conversion of the fuel exergy into work are illustrated by the exergy flow diagram.


1997 ◽  
Vol 119 (3) ◽  
pp. 565-567
Author(s):  
Q. Song ◽  
M. J. Grimble

The algorithm for a multivariable controller using neural network is based on a discrete-time fixed controller and the neural network provides a compensation signal to suppress the nonlinearity. The multivariable neural controller is easy to train and applied to an aircraft gas turbine plant.


Author(s):  
R. W. Ball

The gas turbines owned and operated by utilities throughout the world burn expensive fuels and are under-utilised. Much research work has been done into burning cheaper, alternative fuels. The range of alternative fuels that are available is extensive and the gas turbine can be adapted to burn most of them. The adaptation process will cost the utility money, the pay back period for which depends on the utilisation of the modified plant. Modification of gas turbine plant to burn acceptable fuels can delay purchase of new plant. No major problems are envisaged in the modification of gas turbine plant operated in New Zealand.


Author(s):  
Zheng Qun ◽  
Li Shunglong ◽  
Yang Yaogen

A type of coupled steam–gas turbine plant is proposed here. It is composed of a regenerative extraction steam turbine and a steam injected gas turbine. Extracted steam of the regenerative extraction steam cycle is not used to heat water through the regenerative feed–water heater as in conventional plant, but injected into a gas turbine to augment the output of the gas turbine, while the exhaust gas of the gas turbine now displaces the extracted steam to heat the feed water of the steam turbine plant. The proposed repowering turbine plant has two merits: the further utilization of extraction steam and the elimination of the complicated waste heat recovery boiler of a conventional steam injected gas turbine plant, in favor of a gas–to–water heat exchanger.


Author(s):  
F. R. Spurrier

A gas-turbine engine employed as the main propulsion plant in a ship must satisfy design requirements which differ considerably from those for other turbine applications. The design objectives in a gas-turbine plant for application to naval vessels of medium displacement are discussed in this paper. Such vessels, notably escort types, have duty profile characteristics which demand relatively short periods of operation at maximum power, and long periods at small percentages of maximum power. Normal cruising power may be only 15 per cent of the maximum available but economy of operation must be assured at this condition. In this respect, such engines introduce problems which do not arise in commercial vessels or aircraft-machines, where most of the operating life is spent at high percentages of the maximum available power.


2006 ◽  
Vol 128 (3) ◽  
pp. 535-542 ◽  
Author(s):  
Richard Knight ◽  
Mitsuru Obana ◽  
Christer von Wowern ◽  
Athanasios Mitakakis ◽  
Erhard Perz ◽  
...  

Trends towards distributed power generation and the deregulation of energy markets are increasing the requirement for software tools that optimize power generation plant design and operation. In this context, this paper describes the GTPOM (thermo-economic optimization of whole gas turbine plant) European project, funded in part through the European Commission’s 5th Framework Programme, focusing on the development and demonstration of an original software tool for the thermo-economic analysis and optimization of conventional and advanced energy systems based on gas turbine plant. PSEconomy, the software tool developed during the GTPOM project, provides a thermo-economic optimization capability for advanced and more-conventional energy systems, enabling the complex trade-offs between system performance and installed costs to be determined for different operational duties and market scenarios. Furthermore, the code is capable of determining the potential benefits of innovative cycles or layout modifications to existing plants compared with current plant configurations. The economic assessment is performed through a complete through-life cycle cost analysis, which includes the total capital cost of the plant, the cost of fuel, O&M costs and the expected revenues from the sale of power and heat. The optimization process, carried out with a GA-based algorithm, is able to pursue different objective functions as specified by the User. These include system efficiency, through-life cost of electricity and through-life internal rate of return. Three case studies demonstrating the capabilities of the new tool are presented in this paper, covering a conventional combined cycle system, a biomass plant and a CO2 sequestration gas turbine cycle. The software code is now commercially available and is expected to provide significant advantages in the near and long-term development of energy cycles.


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