Performance Improvement of Small Gas Turbines Through Use of Wave Rotor Topping Cycles

2003 ◽  
Author(s):  
Pezhman Akbari ◽  
Norbert Mu¨ller
Keyword(s):  
Gas Turbines ◽  
Performance Enhancement ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Wave Rotor ◽  
Advantages And Disadvantages ◽  
Turbine Inlet ◽  
Compressor Pressure Ratio ◽  
Significant Performance ◽  
Almost All

Results are presented predicting the significant performance enhancement of two small gas turbines (30 kW and 60 kW) by implementing various wave rotor topping cycles. Five different advantageous implementation cases for a four-port wave rotor into given baseline engines are considered. The compressor and turbine pressure ratios, and the turbine inlet temperatures vary in the thermodynamic calculations, according to the anticipated design objectives of the five cases. Advantages and disadvantages are outlined. Comparison between the theoretic performance (expressed by specific cycle work and overall thermal efficiency) of wave-rotor-topped and baseline engines shows a performance enhancement by up to 33%. The results obtained show that almost all the cases studied benefit from the wave-rotor-topping, but the highest gain is obtained for the case in which the topped engine operates with the same turbine inlet temperature and compressor pressure ratio as the baseline engine. General design maps are generated for the small gas turbines, showing the design space and optima for baseline and topped engines.

Performance Enhancement of One and Two-Shaft Industrial Turboshaft Engines Topped With Wave Rotors

2018 ◽  
Vol 35 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Antonios Fatsis
Keyword(s):  
Gas Turbines ◽  
Performance Enhancement ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Specific Work ◽  
Wave Rotor ◽  
Wave Rotors ◽  
Compressor Pressure Ratio ◽  
Industrial Gas Turbines ◽  
The One

Abstract Wave rotors are rotating equipment designed to exchange energy between high and low enthalpy fluids by means of unsteady pressure waves. In turbomachinery, they can be used as topping devices to gas turbines aiming to improve performance. The integration of a wave rotor into a ground power unit is far more attractive than into an aeronautical application, since it is not accompanied by any inconvenience concerning the over-weight and extra dimensioning. Two are the most common types of ground industrial gas turbines: The one-shaft and the two-shaft engines. Cycle analysis for both types of gas turbine engines topped with a four-port wave rotor is calculated and their performance is compared to the performance of the baseline engine accordingly. It is concluded that important benefits are obtained in terms of specific work and specific fuel consumption, especially compared to baseline engines with low compressor pressure ratio and low turbine inlet temperature.

scholarly journals Performance Enhancement of Microturbine Engines Topped With Wave Rotors

2004 ◽  
Vol 128 (1) ◽  
pp. 190-202 ◽  
Author(s):  
Pezhman Akbari ◽  
Razi Nalim ◽  
Norbert Müller
Keyword(s):  
Gas Turbines ◽  
Design Space ◽  
Performance Enhancement ◽  
Weather Conditions ◽  
Wave Rotor ◽  
Advantages And Disadvantages ◽  
Wave Rotors ◽  
Significant Performance ◽  
Hot Weather ◽  
The Impact

Significant performance enhancement of microturbines is predicted by implementing various wave-rotor-topping cycles. Five different advantageous cases are considered for implementation of a four-port wave rotor into two given baseline engines. In these thermodynamic analyses, the compressor and turbine pressure ratios and the turbine inlet temperatures are varied, according to the anticipated design objectives of the cases. Advantages and disadvantages are discussed. Comparison between the theoretic performance of wave-rotor-topped and baseline engines shows a performance enhancement up to 34%. General design maps are generated for the small gas turbines, showing the design space and optima for baseline and topped engines. Also, the impact of ambient temperature on the performance of both baseline and topped engines is investigated. It is shown that the wave-rotor-topped engines are less prone to performance degradation under hot-weather conditions than the baseline engines.

scholarly journals Gas Turbine Performance Enhancement for Naval Ship Propulsion using Wave Rotors

2019 ◽  
Author(s):  
A Fatsis ◽  
A S N Al Balushi
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Speed ◽  
High Performance ◽  
Performance Enhancement ◽  
Waste Heat ◽  
Specific Power ◽  
Inlet Temperature ◽  
Wave Rotor ◽  
Turbine Inlet

The propulsion demands of high speed naval vessels often rely on gas turbines fitted in small engine rooms, producing significant amounts of power achieving thus high performance requirements. Gas turbines can be used either to provide purely mechanical propulsion, or alternatively to generate electricity, which is subsequently used by electric drives to propel the ship. However, the thermal efficiencies of gas turbines are lower than those of Diesel engines of similar power, in addition to the fact that all gas turbines are less efficient as the ambient temperature rises, particularly for aero-derivative engines. In the context of improving the performance of existing marine gas turbines with minimum modifications to their baseline configuration, this article is proposing engine’s performance enhancement by integrating a pressure wave supercharger (or wave rotor), while keeping the compressor, combustion chamber and turbine entry temperature of the baseline engine unchanged. Thermodynamic cycle analysis for two-shaft gas turbine engines configurations with and without heat exchanger to recuperate the waste heat from the exhaust gases, typical for marine propulsion is performed for the baseline engines, as well as for the topped with four-port wave rotor engines, at design point conditions and their performances are compared accordingly. Important benefits are obtained for four-port wave rotor-topped engines in comparison to the self-standing baseline engines for the whole range of engine’s operation. It is found that the higher the turbine inlet temperature is, the more the benefit gain of the wave rotor topped engine is attained in terms of efficiency and specific power. It is also concluded that the integration of wave rotor particularly favours engines operating at low compressor pressure ratios and high turbine inlet temperatures. The effect of variation of the most important parameters on performance of the topped engine is investigated. It is concluded that wave rotor topping of marine gas turbines can lead to fuel savings and power increase.

Performance analysis of an air humidifier integrated gas turbine with film air cooling of turbine blade

2013 ◽  
Vol 24 (4) ◽  
pp. 71-81 ◽  
Author(s):  
Alok K. Mahapatra ◽  
Sanjay Sanjay
Keyword(s):  
Relative Humidity ◽  
Ambient Temperature ◽  
Pressure Ratio ◽  
Temperature Drop ◽  
Inlet Temperature ◽  
Specific Work ◽  
Blade Cooling ◽  
Ambient Relative Humidity ◽  
Turbine Inlet ◽  
Compressor Pressure Ratio

A computational analysis to investigate the effects of compressor pressure ratio, turbine inlet temperature, ambient relative humidity and ambient temperature on the performance parameters of an air cooled gas turbine cycle with evaporative cooling of inlet air has been presented. The blade cooling method selected is film cooling. The analysis indicates that the mass of coolant required for blade cooling is reduced with increase in temperature drop across the humidifier. Both decrease in ambient temperature and ambient relative humidity results in an increase in plant efficiency and plant specific work. The highest efficiency is obtained at a turbine inlet temperature of 1500 K for all range of ambient relative humidity and ambient temperature, beyond which it decreases. The compressor pressure ratio corresponding to the maximum plant specific work, however, varies with both ambient relative humidity and ambient temperature. The increase in specific work due to drop in ambient relative humidity is more pronounced at higher pressure ratios. Similarly, the increase in efficiency due to ambient temperature drop is prominent at higher turbine inlet temperatures. Finally, a design nomograph is presented to select the design parameters corresponding to best efficiency and specific work.

scholarly journals Evaluation of Bleed Flow Precooling Influence on the Efficiency of the E-MATIANT Cycle

2020 ◽  
Vol 22 (2) ◽  
pp. 593-602 ◽  
Author(s):  
Andrey Rogalev ◽  
Vladimir Kindra ◽  
Alexey Zonov ◽  
Nikolay Rogalev ◽  
Levon Agamirov
Keyword(s):  
Gas Turbines ◽  
Pressure Ratio ◽  
Water Injection ◽  
Design Parameters ◽  
Inlet Temperature ◽  
Combustion Chambers ◽  
Turbine Inlet ◽  
Performance Penalty ◽  
Set Up ◽  
Cycle Efficiency

AbstractThis study aims to present a method for precooling bleed flow by water injection in the E-MATIANT cycle and to estimate its impact on the overall efficiency. The design parameters of the cycle are set up on the basis of the component technologies of today's state-of-the-art gas turbines with a turbine inlet temperature between 1100 and 1700°C. Several schemes of the E-MATIANT cycle are considered: with one, two and three combustion chambers. The optimal pressure ratio ranges for the considered turbine inlet temperatures are identified and a comparison with existing evaluations is made. For the optimal initial parameters, cycle net efficiency varies from 42.0 to 49.8%. A significant influence of turbine stage cooling model on optimal thermodynamic parameters and cycle efficiency is established. The maximum cycle efficiency is 44.0% considering cooling losses. The performance penalty due to the oxygen production and carbon dioxide capture is 20–22%.

A 2000-HP Military Vehicle Gas Turbine: A Study of Significant Thermodynamic and Mechanical Parameters

1968 ◽  
Author(s):  
A. F. Carter
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Overall Design ◽  
Blade Cooling ◽  
Turbine Inlet ◽  
Military Vehicle ◽  
Compressor Pressure Ratio ◽  
Selection Of

During a study of possible gas turbine cycles for a 2000-hp unit for tank propulsion, it has been established that the level of achievable specific fuel consumption (sfc) is principally determined by the combustor inlet temperature. If a regenerative cycle is selected, a particular value of combustor inlet temperature (and hence sfc) can be produced by an extremely large number of combinations of compressor pressure ratio, turbine inlet temperature, and heat exchanger effectiveness. This paper outlines the overall design considerations which led to the selection of a relatively low pressure ratio engine in which the turbine inlet temperature was sufficiently low that blade cooling was not necessary.

Analysis of a Combined Gas Turbine and Absorption-Refrigeration Cycle

1971 ◽  
Vol 93 (1) ◽  
pp. 28-32
Author(s):  
M. M. Nagib
Keyword(s):  
Gas Turbines ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Absorption Refrigeration ◽  
Ambient Temperatures ◽  
Compressor Pressure Ratio ◽  
Average Improvement ◽  
Refrigeration Unit ◽  
Compressor Inlet

An appreciable improvement in the performance of gas turbines operating with ambient temperatures above 90 deg F could be achieved by combining an absorption-refrigeration unit to the power cycle. The thermal energy in the exhaust gases from the turbine is used to operate the refrigeration unit, which in turn cools the air prior to entering the compressor. This reduction in compressor-inlet temperature results an average improvement of about 7–9 points in the thermal efficiency of the combined cycle as well as an increase in the specific output. The analysis includes the effect of different cycle parameters such as compressor pressure ratio, maximum cycle temperature, and regeneration.

scholarly journals The Constant Volume Gas Turbine: A Thermodynamic Assessment

1974 ◽  
Author(s):  
M. Zockel
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Constant Pressure ◽  
Pressure Ratio ◽  
Constant Volume ◽  
Specific Power ◽  
Inlet Temperature ◽  
Turbine Efficiency ◽  
Compressor Pressure Ratio

A quasi-steady-state analysis is made of the performance of a gas-turbine working with intermittent, constant volume combustion. Variables considered include inlet temperature, compressor pressure ratio, scavenge ratio, combustion time, heat exchanger thermal ratio. Characteristics are computed over a full loading range. Computations are based on turbines having the following behavior: (a) constant turbine efficiency, (b) characteristics of a multistage axial turbine, and (c) characteristics of a single-stage radial turbine. The analysis indicates that the constant volume gas turbine has advantages in thermal efficiency, specific power and part load performance over constant pressure gas turbines operating at the same compressor pressure ratio and turbine inlet temperature. However, the addition of a heat exchanger shows less advantage when applied to a constant volume than to a constant pressure engine.

scholarly journals Optimum Power Boosting of Gas Turbine Cycles With Refrigerated Inlet Air and Compressor Intercooling

1996 ◽  
Author(s):  
Mohand A. Ait-Ali
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Turbine Blade Cooling ◽  
High Pressure Ratio ◽  
Blade Cooling ◽  
Air Inlet ◽  
Turbine Inlet ◽  
Compressor Work

With or without turbine blade cooling, gas turbine cycles have consistently higher turbine inlet temperatures than steam turbine cycles. But this advantage is more than offset by the excessive compressor work induced by warm inlet temperatures, particularly during operation on hot summer days. Instead of seeking still higher turbine inlet temperatures by means of sophisticated blade cooling technology and high temperature-resistant blade materials, it is proposed to greatly increase the cycle net work and also improve thermal efficiency by decreasing the compressor work. This is obtained by using refrigerated inlet air and compressor intercooling to an extent which optimizes the refrigerated air inlet temperature and consequently the gas turbine compression ratio with respect to maximum specific net power. The cost effectiveness of this conceptual cycle, which also includes regeneration, has not been examined in this paper as it requires unusually high pressure ratio gas turbines and compressors, as well as high volumetric air flow rate and low temperature refrigeration equipment for which reliable cost data is not easily available.

scholarly journals Exergy, economic and environmental (3E) analysis of a gas turbine power plant and optimization by MOPSO algorithm

2018 ◽  
Vol 22 (6 Part A) ◽  
pp. 2641-2651 ◽  
Author(s):  
Moein Shamoushaki ◽  
Mehdi Ehyaei
Keyword(s):  
Gas Turbine ◽  
Co2 Emission ◽  
Emission Rate ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Total Cost ◽  
Cost Rate ◽  
Turbine Inlet ◽  
Compressor Pressure Ratio

In this paper, exergy, exergoeconomic, and exergoenvironmental analysis of a gas turbine cycle and its optimization has been carried out by MOPSO algorithm. Three objective functions, namely, total cost rate, exergy efficiency of cycle, and CO2 emission rate have been considered. The design variables considered are: compressor pressure ratio, combustion chamber inlet temperature, gas turbine inlet temperature, compressor, and gas turbine isentropic efficiency. The impact of change in gas turbine inlet temperature and compressor pressure ratio on CO2 emission rate as well as impact of changes in gas turbine inlet temperature on exergy efficiency of the cycle has been investigated in different compressor pressure ratios. The results showed that with increase in compressor pressure ratio and gas turbine inlet temperature, CO2 emission rate decreases, that is this reduction is carried out with a steeper slope at lower pressure compressor ratio and gas turbine inlet temperature. The results showed that exergy efficiency of the cycle increases with increase in gas turbine inlet temperature and compressor pressure ratio. The sensitivity analysis of fuel cost changes was performed on objective functions. The results showed that at higher exergy efficiencies total cost rate is greater, and sensitivity of fuel cost optimum solutions is greater than Pareto curve with lower total cost rate. Also, the results showed that sensitivity of changes in fuel cost rate per unit of energy on total cost rate is greater than the rate of CO2 emission.

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