Improvement of gas turbines performance through erosion resistant nanocoatings and exergy analysis

2020 ◽  
Author(s):  
Feiza Memet
Keyword(s):  
Gas Turbines ◽  
Exergy Analysis

Applying Combined Pinch and Exergy Analysis to Closed-Cycle Gas Turbine System Design

1995 ◽  
Vol 117 (1) ◽  
pp. 47-52 ◽  
Author(s):  
V. R. Dhole ◽  
J. P. Zheng
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Exergy Analysis ◽  
Energy Savings ◽  
Design Guidelines ◽  
Closed Cycle ◽  
Practical Design ◽  
Pinch Technology

Pinch technology has developed into a powerful tool for thermodynamic analysis of chemical processes and associated utilities, resulting in significant energy savings. Conventional pinch analysis identifies the most economical energy consumption in terms of heat loads and provides practical design guidelines to achieve this. However, in analyzing systems involving heat and power, for example, steam and gas turbines, etc., pure heat load analysis is insufficient. Exergy analysis, on the other hand, provides a tool for heat and power analysis, although at times it does not provide clear practical design guidelines. An appropriate combination of pinch and exergy analysis can provide practical methodology for the analysis of heat and power systems. The methodology has been successfully applied to refrigeration systems. This paper introduces the application of a combined pinch and exergy approach to commercial power plants with a demonstration example of a closed-cycle gas turbine (CCGT) system. Efficiency improvement of about 0.82 percent (50.2 to 51.02 percent) can be obtained by application of the new approach. More importantly, the approach can be used as an analysis and screening tool for the various design improvements and is generally applicable to any commercial power generation facility.

Exergy Analysis for the Performance Evaluation of Different Setups of the Secondary Air System of Aircraft Gas Turbines

2007 ◽  
Author(s):  
Philipp W. Zeller ◽  
Stephan Staudacher
Keyword(s):  
Performance Evaluation ◽  
Gas Turbines ◽  
Exergy Analysis ◽  
Entropy Increase ◽  
Engine Efficiency ◽  
Specific Entropy ◽  
Air System ◽  
Exergy Method ◽  
Secondary Air ◽  
Careful Design

Secondary Air System related losses in aircraft gas turbines cannot be directly assessed and quantified as possible for other sub-systems of the engine. If a particular setup is to be evaluated and compared to other, competing designs, it is required to have a distinct understanding of the loss mechanisms and the way these losses appear in the cycle. The relevant loss phenomena are therefore discussed in detail and are quantified with regard to the respective specific entropy increase. The exergy method is found to be the method of choice, since it holds some important advantages compared to other loss accounting methods like gas horsepower or thrust work potential. An exergy analysis is carried out for a high TET, two shaft engine of the medium thrust range. A comparison of setups with different compressor offtake positions is performed. It is found that the contribution of Air System related losses to overall engine efficiency deficits is significant, but may be reduced by careful design.

scholarly journals Energy and Exergy Analysis of Coupled Cycles Utilizing New Generation Gas Turbines

2020 ◽  
Author(s):  
Chang Cho
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Closed Loop ◽  
Exergy Analysis ◽  
Cooling Process ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Combined Cycles ◽  
New Generation

The potential execution of optimized gas-steam combined cycles built around the latest generation gas turbine motors is analyzed, by implies of energy/exergy equalizations. The options here considered are the warm gas turbine and the H-series with closed-loop steam edge cooling.Recreations of execution were run employing a well-tested Modular Code created at the Office of Vitality Designing of Florence and subsequently improved to incorporate the calculation of exergy pulverization of all sorts (warm transfer, friction, blending, and chemical irreversibilities). The edge cooling process is analyzed in detail because it is recognized to be of capital significance for execution optimization. The distributions of the relative exergy devastation for the two solutions both competent of achieving energy/exergy efficiencies within the extend of 60 percent are compared and the potential for advancement is examined<br>

scholarly journals Energy and exergy analysis of a simple gas turbine combined with linde cycle and N2 injected into the compressor of the gas turbine

2021 ◽  
Vol 1 (1) ◽  
pp. 006-015
Author(s):  
E. H. Betelmal ◽  
A. M. Naas ◽  
A. Mjani
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Exergy Analysis ◽  
Air Separation ◽  
Compression Process ◽  
Turbine Efficiency ◽  
Performance Variation ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Gas Turbine Cycle

In this paper, we investigated a thermodynamic model of the regeneration gas turbine cycle with nitrogen supplied during the compression process. A suitable quantity of nitrogen that comes from the air separation cycle (Linde cycle) is injected between the stages of the compressor where it is evaporated, then the nitrogen and air mixture enters into the combustion chamber where it is burned and expanded in the turbine. We used this method to reduce greenhouse gases and improve gas turbine efficiency. In this work, we evaluated the operational data of the regeneration gas turbine cycle and the maximum amount of nitrogen that can be injected into the compressor. We also investigated the performance variation due to nitrogen spray into the compressor, and the effect of varying ambient temperature on the performance of gas turbines (thermal efficiency, power), as well as a comparison between the normal gas turbine cycle, and the remodelled compression cycle. The exergy analysis shows that the injection of the nitrogen will increase exergy destruction. The results demonstrated an 8% increase in the efficiency of the cycle, furthermore, CO2 emission decreased by 11% when the nitrogen was injected into the compressor.

scholarly journals Exergy Efficiency Optimization for Gas Turbine Based Cogeneration Systems

2013 ◽  
Author(s):  
Ana C. Ferreira ◽  
Senhorinha F. Teixeira ◽  
José C. Teixeira ◽  
Manuel L. Nunes ◽  
Luís B. Martins
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Exergy Analysis ◽  
Exergy Efficiency ◽  
Plant Performance ◽  
System Component ◽  
Inlet Temperature ◽  
Exergy Destruction ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet

Energy degradation can be calculated by the quantification of entropy and loss of work and is a common approach in power plant performance analysis. Information about the location, amount and sources of system deficiencies are determined by the exergy analysis, which quantifies the exergy destruction. Micro-gas turbines are prime movers that are ideally suited for cogeneration applications due to their flexibility in providing stable and reliable power. This paper presents an exergy analysis by means of a numerical simulation of a regenerative micro-gas turbine for cogeneration applications. The main objective is to study the best configuration of each system component, considering the minimization of the system irreversibilities. Each component of the system was evaluated considering the quantitative exergy balance. Subsequently the optimization procedure was applied to the mathematical model that describes the full system. The rate of irreversibility, efficiency and flaws are highlighted for each system component and for the whole system. The effect of turbine inlet temperature change on plant exergy destruction was also evaluated. The results disclose that considerable exergy destruction occurs in the combustion chamber. Also, it was revealed that the exergy efficiency is expressively dependent on the changes of the turbine inlet temperature and increases with the latter.

scholarly journals Exergy Analysis of Combined Cycles Using Latest Generation Gas Turbines

1999 ◽  
Author(s):  
Bruno Facchini ◽  
Daniele Fiaschi ◽  
Giampaolo Manfrida
Keyword(s):  
Gas Turbine ◽  
Performance Optimization ◽  
Gas Turbines ◽  
Exergy Analysis ◽  
Department Of Energy ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Exergy Destruction ◽  
Blade Cooling ◽  
Combined Cycles

The potential performance of optimized gas-steam combined cycles built around latest-generation gas turbine engines is analyzed, by means of energy/exergy balances. The options here considered are the reheat gas turbine and the H-series with closed-loop steam blade cooling. Simulations of performance were run using a well-tested Modular Code developed at the Department of Energy Engineering of Florence and subsequently improved to include the calculation of exergy destruction of all types (heat transfer, friction, mixing and chemical irreversibilities). The blade cooling process is analyzed in detail as it is recognized to be of capita] importance for performance optimization. The distributions of the relative exergy destruction for the two solutions — both capable of achieving energy/exergy efficiencies in the range of 60% — are compared and the potential for improvement is discussed.

On-Design and Off-Design Performance Analysis of a Gas Turbine Combined Cycle Using the Exergy Method

2000 ◽  
Author(s):  
Alcides Codeceira Neto ◽  
Pericles Pilidis
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Exergy Analysis ◽  
Pressure Ratio ◽  
Calorific Value ◽  
Combined Cycle ◽  
Exergy Destruction ◽  
Turbine Engine ◽  
Design Point

The present paper describes an on-design and an off-design performance study of gas turbine combined cycle based power plants. The exergy analysis has been carried out along with the performance assessment, considering the overall plant exergetic efficiency and the exergy destruction in the various components of the plant. The exergy method highlights irreversibility within the plant components, and it is of particular interest in this investigation. A computational analysis has been carried out to investigate the effects of compressor pressure ratio and gas turbine entry temperature on the thermodynamic performance of combined gas / steam power cycles. The exergy analysis has been performed for on-design point calculations, considering single shaft gas turbines with different compressor pressure ratios and turbine entry temperatures. Nearly 100 MW shaft power gas turbine engines burning natural gas fuel have been selected in this study. The off-design calculations have been performed for one of the gas turbines selected from the on-design point studies. For this particular gas turbine engine, fuel has been changed from natural gas to a low calorific value fuel gas originated from the gasification of wood. The exergy analysis indicates that maximum exergy is destroyed in the combustor, in the case of combined gas / steam cycles burning natural gas. For these studies on-design point, the exergy destruction in the combustor is found to decrease with increasing compressor pressure ratio to an optimum value and with increasing turbine entry temperature. In the off-design case the gas turbine engine is burning low calorific value fuel originated from the gasification of wood. The maximum exergy destruction occurs in the gasification process, followed by the combustion process in the gas turbine.

Exergy Analysis of Combined Cycles Using Latest Generation Gas Turbines

2000 ◽  
Vol 122 (2) ◽  
pp. 233-238 ◽  
Author(s):  
Bruno Facchini ◽  
Daniele Fiaschi ◽  
Giampaolo Manfrida
Keyword(s):  
Gas Turbine ◽  
Performance Optimization ◽  
Gas Turbines ◽  
Exergy Analysis ◽  
Department Of Energy ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Exergy Destruction ◽  
Blade Cooling ◽  
Combined Cycles

The potential performance of optimized gas-steam combined cycles built around latest-generation gas turbine engines is analyzed, by means of energy/exergy balances. The options here considered are the reheat gas turbine and the H-series with closed-loop steam blade cooling. Simulations of performance were run using a well-tested Modular Code developed at the Department of Energy Engineering of Florence and subsequently improved to include the calculation of exergy destruction of all types (heat transfer, friction, mixing, and chemical irreversibilities). The blade cooling process is analyzed in detail as it is recognized to be of capital importance for performance optimization. The distributions of the relative exergy destruction for the two solutions—both capable of achieving energy/exergy efficiencies in the range of 60 percent—are compared and the potential for improvement is discussed. [S0742-4795(00)00902-9]

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