The Entropy and Exergy Analyses of Wet Compression Gas Turbine

2005 ◽  
Author(s):  
Yan Shao ◽  
Qun Zheng
Keyword(s):  
Gas Turbine ◽  
Thermodynamic Parameters ◽  
Thermodynamic Analysis ◽  
Thermodynamic Models ◽  
Compression Process ◽  
Wet Compression ◽  
Gas Turbine Cycle ◽  
Exergy Analyses

Wet compression is an effective way of gas turbine power augmentation, but at the same time it causes some new thermodynamic problems. How to evaluate the thermodynamic parameters and how to improve the wet compression process and wet compression gas turbine cycle are key to the actual applications of the technique in industries. From the entropy and exergy views, wet compression processes are analyzed in this paper. By calculating the entropy and exergy variations with the established thermodynamic models of wet compression process, we presented some interesting results that could used to reduce the increase of entropy and the loss of exergy in the wet compression process. On the basis of thermodynamic analysis of wet compression, the entropy and exergy effects at different evaporative rates, different pressure ratios etc. are further investigated in this paper.

Influence of Water Droplet Size and Temperature on Wet Compression

2007 ◽  
Author(s):  
M. Bianchi ◽  
F. Melino ◽  
A. Peretto ◽  
P. R. Spina ◽  
S. Ingistov
Keyword(s):  
Gas Turbine ◽  
Water Droplet ◽  
Droplet Diameter ◽  
Axial Compressor ◽  
Combined Cycle ◽  
Water Evaporation ◽  
Air Cooling ◽  
Compression Process ◽  
Two Phase ◽  
Wet Compression

In the last years, among all different gas turbine inlet air cooling techniques, an increasing attention to fogging approach is dedicated. The various fogging strategies seem to be a good solution to improve gas turbine or combined cycle produced power with low initial investment cost and less installation downtime. In particular, overspray fogging and interstage injection involve two-phase flow consideration and water evaporation during compression process (also known as wet compression). According to the Author’s knowledge, the field of wet compression is not completely studied and understood. In the present paper, all the principal aspects of wet compression and in particular the influence of injected water droplet diameter and surface temperature, and their effect on gas turbine performance and on the behavior of the axial compressor (change in axial compressor performance map due to the water injection, redistribution of stage load, etc.) are analyzed by using a calculation code, named IN.FO.G.T.E. (INterstage FOgging Gas Turbine Evaluation), developed and validated by the Authors.

BASIC POSITIONS OF THE ENTHALPY-ENTROPY METHODOLOGY OF THERMODYNAMIC ANALYSIS OF GAS TURBINE POWER PLANTS

2017 ◽  
Author(s):  
Gennadii Liubchik ◽  
◽  
Nataliia Fialko ◽  
Aboubakr Regragui ◽  
Nataliia Meranova ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Thermodynamic Parameters ◽  
Thermodynamic Analysis ◽  
Thermodynamic Modeling ◽  
Power Plants ◽  
Regression Equations ◽  
Thermal Entropy ◽  
Nodal Points ◽  
Computational Diagnostics

The basic positions of the enthalpy-entropy methodology of thermodynamic modeling of processes in gas turbine units (GTUs) and combined power plants on basis GTUs are presented. The main requirements and conditions of this methodology are formulated, they allows the construction of a sequential (without iterations) algorithm for the computational diagnostics of the thermodynamic parameters of the GTU cycle, which includes the calculation blocks for the compressor, combustion chamber, turbine, and exhaust tube of the GTU. The obtained regression equations are presented. The use of these equations simplifies of the procedure for evaluating the thermodynamic parameters of the components at the nodal points of the cycle. The advantages of the proposed methodology in comparison with the traditional thermal-entropy methodology are indicated.

Refinement of Water Droplets With Surfactants for Wet Compression of Gas Turbine

2009 ◽  
Author(s):  
Rongkai Zhu ◽  
Qun Zheng ◽  
Guoqiang Yue ◽  
Rakesh Bhargava
Keyword(s):  
Surface Tension ◽  
Gas Turbine ◽  
Experimental Work ◽  
Ionic Surfactants ◽  
Water Droplets ◽  
Compression Process ◽  
Surface Behavior ◽  
Wet Compression ◽  
The Cost

Concerned with the influence of the size of water droplets on the effect of wet compression, it is important to control the size of water droplets among 5–10 microns or smaller, for this purpose an experimental work is carried out by improve the surface behavior of water aiming to reduce its surface tension. Non-ionic surfactants and its combination were employed to reach such an aim. The surface tension of water was reduced from 72.9mN/m to 41.2mN/m or even lower depending on the cost. It offers a possible way to refine spray, and ready to use in wet compression process.

scholarly journals Energy and Exergy Analysis of a Simple Gas Turbine Cycle with Wet Compression

2018 ◽  
Vol 8 (1) ◽  
pp. 30 ◽  
Author(s):  
E. H. Betelmal ◽  
S. A. Farhat
Keyword(s):  
Gas Turbine ◽  
Water Injection ◽  
Analytical Formula ◽  
Heat Rate ◽  
Performance Model ◽  
Exergy Destruction ◽  
Isentropic Compression ◽  
Turbine Efficiency ◽  
Wet Compression ◽  
Gas Turbine Cycle

A thermodynamic model of the wet compressor in a simple gas turbine cycle was investigated in this paper. A suitable quantity of water was injected into the compressor-stages where it evaporated. Subsequently, the steam and air were heated in the combustion chamber and expanded in the turbine. The wet compressor (WC) has become a reliable way to reduce gas emissions and increase gas turbine efficiency. In this study, the operational data of the simple gas turbine and the maximum amount of water that can be injected into the compressor were assessed, as well as a comparison between the dry compression, the wet compression and the isentropic compression. The performance variation due to water spray in the compressor and the effect of varying ambient temperature on the performance of gas turbine (thermal efficiency, power) was investigated, and the results are compared to the results of the same cycle with a dry compressor. The analytical formula of exergy destruction and results show that exergy destruction increases with water injection. The programming of the performance model for the gas turbine was developed utilizing the software IPSEpro. The results of the gas turbine with a wet compressor demonstrates a 12% reduction in the compressor exit temperature up to isentropic temperature. The compressor work decreased by 11% when using a wet compressor, this lead to an improvement in power output and efficiency However, the wet compressor increases the specific fuel consumption and heat rate of the gas turbine. There are limitations in the amount of steam that can be injected, 0.4 kg/s of water was the optimum amount injected into the compressor.

Evaluation of the Compression-Intercooled Reheat-Gas-Turbine-Combined Cycle

1984 ◽  
Author(s):  
Ivan G. Rice
Keyword(s):  
Gas Turbine ◽  
Thermodynamic Analysis ◽  
Pressure Range ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Time Increase ◽  
Efficiency Loss ◽  
Gas Turbine Cycle ◽  
Cycle Efficiency ◽  
Turbine Output

Interest in the reheat-gas turbine (RHGT) as a way to improve combined-cycle efficiency is gaining momentum. Compression intercooling makes it possible to readily increase the reheat-gas-turbine cycle-pressure ratio and at the same time increase gas-turbine output; but at the expense of some combined-cycle efficiency and mechanical complexity. This paper presents a thermodynamic analysis of the intercooled cycle and pinpoints the proper intercooling pressure range for minimum combined-cycle-efficiency loss. At the end of the paper two-intercooled reheat-gas-turbine configurations are presented.

Flow Assessment on the Effects of Water Droplets on Rotor Region of Wet Compression

2017 ◽  
Vol 374 ◽  
pp. 131-147
Author(s):  
Gambo Kofar Bai Dayyabu ◽  
Hai Zhang ◽  
Qun Zheng ◽  
Salman Abdu
Keyword(s):  
Gas Turbine ◽  
Gas Flow ◽  
Fluid Dynamic ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Water Droplets ◽  
Compression Process ◽  
Transonic Compressor ◽  
Depth Analysis ◽  
Wet Compression

Wet compression process has been widely accepted as a measure of increasing the performance of industrial gas turbine, in the present work, in-depth analysis on the principle aspects of wet compression, more specifically, the influence of injected water droplets diameter, surface temperature, and their effects on the behavior of axial flow transonic compressor and gas turbine performance were analyzed using computational fluid dynamic. Injected water droplets and gas flow phase change was most intense in the area adjacent to shockwaves and were the slip velocity of the droplet is highest. Water injection in to the compressor rotor is a little perturbation to the flow field due to the formation of flow separation, evaporation rate, increasing weber number, reduction in the inlet temperature, and velocity vortex pattern relatively different from that of the dry case. The effects of water droplets on the rotor region at injection rate of 1%, shows decrease in the inlet temperature of 11%, outlet temperature 5% and uplift the efficiency to 1.5%.

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.

Formation Process of Water Film and Performance Effect on Compressor Stage

2016 ◽  
Author(s):  
Hai Zhang ◽  
Xiaojiang Tian ◽  
Xiaojun Pan ◽  
Jie Zhou ◽  
Qun Zheng
Keyword(s):  
Gas Turbine ◽  
Formation Process ◽  
Water Injection ◽  
Water Film ◽  
Compressor Stage ◽  
Blade Surface ◽  
Water Droplets ◽  
Compression Process ◽  
Turbine Performance ◽  
Wet Compression

In process of wet compression, gas turbine engine will ingest a certain amount of water, which can influence the overall performance of the engine. This phenomenon is particularly significant in the cleaning process of industrial gas turbine and water injection of aero-engine. When the quantity of water ingestion is quite large, the performance of gas turbine will appear deterioration and may lead to flameout, power reduce or even shutdown of the engine, causing accidents. Water droplets will be accumulated on the blade surface where water films could be formed on pressure surface in the wet compression process. The effects of water film on gas turbine engines are aerodynamic, thermodynamic and mechanical. The above-mentioned effects occur simultaneously and be affected by each other. Considering the above effects and the fact that they are time dependent, there are few gas turbine performance researches, which take into account the water film phenomenon. This study is a new research of investigating theoretically the water film effects on a gas turbine performance. It focuses on the aerodynamic and thermodynamic effects of the phenomenon on the compressor stage. The computation of water film thickness, which frequently be formed on the surface of compressor blade, its movement and extra torque demand, are provided by a simulation model of the code. Considering the change in blade’s profile and the thickness feature of the water film, the compressor stage’s performance deterioration is analyzed. In addition to this, movement and the formation of the water film on a compressor stage are simulated and analyzed by using unsteady numerical methods under different water injecting conditions in this paper. The movement characteristics of water droplets in compressor passage are investigated to understand the flow mechanisms responsible for water film formation process. The forming and the tearing process of water film on blade surface are analyzed at different injection conditions. For simulating the real situation, The maximum quantity of injected water can reach 12%. The results indicate that continuity and region of the water film on the blade surface will be developed with the increment of droplet size and injection rate. It is also found that the flow losses near blade surface increases with the tearing process of water film due to the increment of surface roughness.

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