Effects of Intake Air Cooling Performance Improvement on a Two-Shaft Laboratory-Scale Gas Turbine Unit

2007 ◽  
Author(s):  
Hussain Al-Madani ◽  
Teoman Ayhan ◽  
Omar Al-Abbasi
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Performance Test ◽  
Second Law ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Proposed Model ◽  
Compressor Inlet

The present study deals with the thermodynamically modelled two-shaft gas turbine system consisting of a cooling unit at the compressor inlet. The system is used to investigate the generated power, thermal efficiency and second law efficiency. The parametric study using this model shows effect of ambient conditions, compressor inlet temperature, and pressure ratios on power output, thermal efficiency and second law efficiency. Theoretical results using the proposed model show that when the compressor inlet temperature is decreased by some kind of cooling systems, the net power output and thermal efficiency increases up to 30% and 23%, respectively. Also, the second law efficiency of the proposed system increases in compression to the specified reference state. It shows that the proposed model is thermodynamically viable. A comparison of the performance test results of the model and the experimental results are in good agreement. The results provide valuable information regarding the gas turbine system and will be useful for designers.

Optimum Performance Improvements of the Combined Cycle Based on an Intercooler–Reheated Gas Turbine

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Thamir K. Ibrahim ◽  
M. M. Rahman
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Optimum Level ◽  
Simulation Code ◽  
Operation Conditions ◽  
Turbine Inlet

The performance enhancements and modeling of the gas turbine (GT), together with the combined cycle gas turbine (CCGT) power plant, are described in this study. The thermal analysis has proposed intercooler–reheated-GT (IHGT) configuration of the CCGT system, as well as the development of a simulation code and integrated model for exploiting the CCGT power plants performance, using the matlab code. The validation of a heavy-duty CCGT power plants performance is done through real power plants, namely, MARAFIQ CCGT plants in Saudi Arabia with satisfactory results. The results from this simulation show that the higher thermal efficiency of 56% MW, while high power output of 1640 MW, occurred in IHGT combined cycle plants (IHGTCC), having an optimal turbine inlet temperature about 1900 K. Furthermore, the CCGT system proposed in the study has improved power output by 94%. The results of optimization show that the IHGTCC has optimum power of 1860 MW and thermal efficiency of 59%. Therefore, the ambient temperatures and operation conditions of the CCGT strongly affect their performance. The optimum level of power and efficiency is seen at high turbine inlet temperatures and isentropic turbine efficiency. Thus, it can be understood that the models developed in this study are useful tools for estimating the CCGT power plant's performance.

Performance of a Novel Semiclosed Gas-Turbine Refrigeration Combined Cycle

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Joseph J. Boza ◽  
William E. Lear ◽  
S. A. Sherif
Keyword(s):  
High Pressure ◽  
Ambient Temperature ◽  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Combined Cycle ◽  
Water Mixture ◽  
Absorption Refrigeration ◽  
Ambient Conditions ◽  
Large Engine

A thermodynamic performance analysis was performed on a novel cooling and power cycle that combines a semiclosed gas turbine called the high-pressure regenerative turbine engine (HPRTE) with an absorption refrigeration unit. Waste heat from the recirculated combustion gas of the HPRTE is used to power the absorption refrigeration cycle, which cools the high-pressure compressor inlet of the HPRTE to below ambient conditions and also produces excess refrigeration depending on ambient conditions. Two cases were considered: a small engine with a nominal power output of 100kW and a large engine with a nominal power output of 40MW. The cycle was modeled using traditional one-dimensional steady-state thermodynamics, with state-of-the-art polytropic efficiencies and pressure drops for the turbomachinery and heat exchangers, and curve fits for properties of the LiBr-water mixture and the combustion products. The small engine was shown to operate with a thermal efficiency approaching 43% while producing 50% as much 5°C refrigeration as its nominal power output (roughly 50tons) at 30°C ambient conditions. The large engine was shown to operate with a thermal efficiency approaching 62% while producing 25% as much 5°C refrigeration as its nominal power output (roughly 20,000tons) at 30°C ambient conditions. Thermal efficiency stayed relatively constant with respect to ambient temperature for both the large and small engines. It decreased by only 3–4% as the ambient temperature was increased from 10°Cto35°C in each case. The amount of external refrigeration produced by the engine sharply decreased in both engines at around 35°C, eventually reaching zero at roughly 45°C in each case for 5°C refrigeration. However, the evaporator temperature could be raised to 10°C (or higher) to produce external refrigeration in ambient temperatures as high as 50°C.

Influence of Ambient Conditions on an Aeroderivative Gas Turbine Based Cogeneration Plant — A Comparison of Numerical Simulation With Field Performance Data

2000 ◽  
Author(s):  
Carlo Carcasci ◽  
Bruno Facchini ◽  
Francesco Grillo
Keyword(s):  
Numerical Simulation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Field Performance ◽  
Performance Data ◽  
Plant Performance ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Compressor Inlet

Gas turbine performances are directly related to outside conditions. The use of gas turbines in combined gas-steam power plants, also applied to cogeneration, increases performance dependence by outside conditions, because plants boundary conditions become more complex. In recent years, inlet air cooling systems have been introduced to control air temperature and humidity at compressor inlet resulting in an increase in plant power and efficiency. In this paper, the dependence of outside conditions for an existing cogenerative plant, located in Tuscany (Italy), is studied. The plant is equipped with two GE-LM6000 aeroderivative gas-turbines coupled with a three pressure level heat recovery steam generator, cogenerative application being related to the industrial district. The ambient temperature has been found to be the most important factor affecting the plant performance, but relative air humidity variation also has considerable effects. The field performance data are compared with a numerical simulation. The simulation results show a good agreement with the field performance data. The simulation allows evaluation of design and off-design plant performance and can become a useful tool to study the outside condition influence on power plant performance.

Genetic Optimization of Steam Injected Gas Turbine Power Plants

2002 ◽  
Author(s):  
Ibrahim Sinan Akmandor ◽  
O¨zhan O¨ksu¨z ◽  
Sec¸kin Go¨kaltun ◽  
Melih Han Bilgin
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Power Plants ◽  
Pressure Ratio ◽  
Steam Injection ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Compressor Pressure Ratio

A new methodology is developed to find the optimal steam injection levels in simple and combined cycle gas turbine power plants. When steam injection process is being applied to simple cycle gas turbines, it is shown to offer many benefits, including increased power output and efficiency as well as reduced exhaust emissions. For combined cycle power plants, steam injection in the gas turbine, significantly decreases the amount of flow and energy through the steam turbine and the overall power output of the combined cycle is decreased. This study focuses on finding the maximum power output and efficiency of steam injected simple and combined cycle gas turbines. For that purpose, the thermodynamic cycle analysis and a genetic algorithm are linked within an automated design loop. The multi-parameter objective function is either based on the power output or on the overall thermal efficiency. NOx levels have also been taken into account in a third objective function denoted as steam injection effectiveness. The calculations are done for a wide range of parameters such as compressor pressure ratio, turbine inlet temperature, air and steam mass flow rates. Firstly, 6 widely used simple and combined cycle power plants performance are used as test cases for thermodynamic cycle validation. Secondly, gas turbine main parameters are modified to yield the maximum generator power and thermal efficiency. Finally, the effects of uniform crossover, creep mutation, different random number seeds, population size and the number of children per pair of parents on the performance of the genetic algorithm are studied. Parametric analyses show that application of high turbine inlet temperature, high air mass flow rate and no steam injection lead to high power and high combined cycle thermal efficiency. On the contrary, when NOx reduction is desired, steam injection is necessary. For simple cycle, almost full amount of steam injection is required to increase power and efficiency as well as to reduce NOx. Moreover, it is found that the compressor pressure ratio for high power output is significantly lower than the compressor pressure ratio that drives the high thermal efficiency.

scholarly journals Fog and Overspray Cooling for Gas Turbine Systems With Low Calorific Value Fuels

2006 ◽  
Author(s):  
Jobaidur Rahman Khan ◽  
Ting Wang
Keyword(s):  
Gas Turbine ◽  
Output Power ◽  
Power Output ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Alternative Fuels ◽  
Calorific Value ◽  
Ambient Conditions ◽  
Turbine Inlet ◽  
Compressor Power

During the summer, power output and the efficiency of gas turbines deteriorate significantly. Gas turbine inlet air fog cooling is considered a simple and cost-effective method to increase power output as well as, sometimes, thermal efficiency. During fog cooling, water is atomized to micro-scaled droplets and introduced into the inlet airflow. In addition to cooling the inlet air, overspray can further enhance output power by intercooling the compressor. With continued increase of volatility of natural gas prices and concerns regarding national energy security, alternative fuels such as low calorific value (LCV) synthetic gases (syngas) derived from gasification of coal, petroleum coke, or biomass are considered as important common fuels in the future. The effect of fogging/overspray on LCV fuel fired gas turbine systems is not clear. This paper specifically investigates this issue by developing a wet compression thermodynamic model that considers additional water and LCV fuel mass flows, non-stoichiometric combustion, and the auxiliary fuel compressor power. An in-house computational program, FogGT, has been developed to study the theoretical gas turbine performance by fixing the pressure ratio and turbine inlet temperature (TIT) assuming the gas turbine has been designed or modified to take in the additional mass flow rates from overspray and LCV fuels. Two LCV fuels of approximately 8% and 15% of the NG heating values, are considered respectively. Parametric studies have been performed to consider different ambient conditions and various overspray ratios with fuels of different low heating values. The results show, when LCV fuels are burned, the fuel compressor consumes about 10–18% of the turbine output power in comparison with 2% when NG is burned. LCV fueled GT is about 10–16% less efficient than NG fueled GT and produces 10–24% of net output power even though LCV fuels significantly increase fuel compressor power. When LCV fuels are burned, saturated fogging can achieve a net output power increases approximately 1–2%, while 2% overspray can achieve 20% net output enhancement. As the ambient temperature or relative humidity increases, the net output power decreases. Fog/overspray could either slightly increase or decrease the thermal efficiency depending on the ambient conditions.

Thermodynamic and Energy Study of a Regenerator in Gas Turbine Cycle and Optimization of Performances

2016 ◽  
Vol 5 (2) ◽  
pp. 25-44
Author(s):  
Saria Abed ◽  
Taher Khir ◽  
Ammar Ben Brahim
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Parametric Study ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Compressor Pressure Ratio ◽  
Compressor Inlet ◽  
Gas Turbine Cycle

In this paper, thermodynamic study of simple and regenerative gas turbine cycles is exhibited. Firstly, thermodynamic models for both cycles are defined; thermal efficiencies of both cycles are determined, the overall heat transfer coefficient through the heat exchanger is calculated in order to determinate its performances and parametric study is carried out to investigate the effects of compressor inlet temperature, turbine inlet temperature and compressor pressure ratio on the parameters that measure cycles' performance. Subsequently, numerical optimization is established through EES software to determinate operating conditions. The results of parametric study have shown a significant impact of operating parameters on the performance of the cycle. According to this study, the regeneration technique improves the thermal efficiency by 10%. The studied regenerator has an important effectiveness (˜ 82%) which improves the heat transfer exchange; also a high compressor pressure ratio and an important combustion temperature can increase thermal efficiency.

scholarly journals Investigation of the Combined Effect of Variable Inlet Guide Vane Drift, Fouling, and Inlet Air Cooling on Gas Turbine Performance

Entropy ◽  
2019 ◽  
Vol 21 (12) ◽  
pp. 1186 ◽  
Author(s):  
Muhammad Baqir Hashmi ◽  
Tamiru Alemu Lemma ◽  
Zainal Ambri Abdul Karim
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Guide Vane ◽  
Inlet Guide Vane ◽  
Air Cooling ◽  
Turbine Performance ◽  
Surge Margin ◽  
Performance Deterioration ◽  
Variable Inlet Guide Vane

Variable geometry gas turbines are susceptible to various malfunctions and performance deterioration phenomena, such as variable inlet guide vane (VIGV) drift, compressor fouling, and high inlet air temperatures. The present study investigates the combined effect of these performance deterioration phenomena on the health and overall performance of a three-shaft gas turbine engine (GE LM1600). For this purpose, a steady-state simulation model of the turbine was developed using a commercial software named GasTurb 12. In addition, the effect of an inlet air cooling (IAC) technique on the gas turbine performance was examined. The design point results were validated using literature results and data from the manufacturer’s catalog. The gas turbine exhibited significant deterioration in power output and thermal efficiency by 21.09% and 7.92%, respectively, due to the augmented high inlet air temperature and fouling. However, the integration of the inlet air cooling technique helped in improving the power output, thermal efficiency, and surge margin by 29.67%, 7.38%, 32.84%, respectively. Additionally, the specific fuel consumption (SFC) was reduced by 6.88%. The VIGV down-drift schedule has also resulted in improved power output, thermal efficiency, and the surge margin by 14.53%, 5.55%, and 32.08%, respectively, while the SFC decreased by 5.23%. The current model can assist in troubleshooting the root cause of performance degradation and surging in an engine faced with VIGV drift and fouling simultaneously. Moreover, the combined study also indicated the optimum schedule during VIGV drift and fouling for performance improvement via the IAC technique.

scholarly journals Parametric Performance of Ultra-light Gas Turbine Power Plant for Heavy Lift Multicopters Flight Systems Using Astra - Russian Aviation Engine Optimization Software

2018 ◽  
Vol 220 ◽  
pp. 03011
Author(s):  
T. Aurthur Vimalachandran ◽  
Andrey Yurievich Tkachenko ◽  
Viktor Nikolaevich Rybakov
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Parametric Analysis ◽  
Fuel Efficiency ◽  
Inlet Temperature ◽  
Maximum Output ◽  
Operation Condition ◽  
Gas Turbine Power Plant

A detailed parametric analysis was performed on entire performance cycle model of micro gas turbine power plant. The parametric analysis was studied using Russian Software named ASTRA. Evaluation of parameters on both design and operation condition was performed. The parameters focused here are power output, compression work, specific fuel consumption and thermal efficiency. Various stages such as use of Intercooler, Pre-heater and their optimal influence on thermodynamics were performed. The task was to optimize the maximum output in free turbine power by simulating various cycles of compressor pressure ratios for centrifugal compressor, ambient temperature in various altitude; air-fuel mix ratio and turbine inlet temperature. The results are analysed and presented in this article, the Analysis known as on-design analysis. The compressor uses 66% of turbine work output. The research analysis focuses on reducing the use of power output by compressor and maximizes the power output by free turbine. The results could be summarized as increase in gas turbine thermal efficiency does not always improve the gas turbine efficiency. Optimum power increase of up to 3% was improved and improvement in fuel efficiency improved about 4%.

ANALYSIS OF THERMAL EFFICIENCY OF OPEN CYCLE GAS TURBINE POWER PLANT AT PUTRAJAYA (MALAYSIA)

2015 ◽  
Vol 76 (5) ◽  
Author(s):  
Alhassan Salami Tijani ◽  
Mohd Rashid Halim
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Compressor Inlet ◽  
Current Cycle ◽  
Open Cycle ◽  
Gas Turbine Power Plant ◽  
Regenerative Cycle

The purpose of this paper is to study the performance of an existing open cycle gas turbine power plant at Putrajaya power station. At compressor inlet temperature of 298.90K, thermal efficiency of 31 % was observed for the existing or current cycle whiles the modified configuration yielded thermal efficiency of 45 %, this result in 14 % increase in thermal efficiency. At pressure ratio of 3.67, thermal efficiency of about 31.06% and 44% was recorded for the current cycle and regenerative cycle respectively. The efficiency of both cycles increase considerably with increase in pressure ratio, but at pressure ratio of about 7, only a small increase in efficiency for both cycles was observed. The optimum value of the efficiencies for both cycles that correspond to pressure ratio of 7 is 43.06 and 56% for the current cycle and the regenerative cycle respectively.

Thermal-Economic Evaluation of Evaporative Inlet Cooling Methods for Ray Gas Turbine Power Plant

2004 ◽  
Author(s):  
Sepehr Sanaye ◽  
Abbasali Farhad ◽  
Mohsen Ebrahimi
Keyword(s):  
Economic Evaluation ◽  
Power Plant ◽  
Gas Turbine ◽  
Power Output ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Evaporative Cooling ◽  
Ambient Conditions ◽  
Operational Conditions ◽  
Cooling Methods

The ambient conditions (temperature, pressure and humidity) affect the gas turbine power output and thermal efficiency [1–8]. Increasing one Celsius degree of ambient temperature decreases the power output for about 0.5 to 0.9 percent and the thermal efficiency for about 0.25 percent. Evaporating cooling is efficient and cost effective method for gas turbine inlet cooling to improve the power output and efficiency, specially in hot and dry regions. A systematic thermo-economic evaluation of the three evaporative inlet cooling methods applied to existing 25 MW Fiat gas turbine in Ray power plant, is presented in this paper. The three inlet cooling methods considered are: evaporative inlet fogging, media type evaporative cooling and inlet cooling through air washer. The investment and maintenance costs, the income from increasing the power output, the costs of increasing fuel consumption, and power loss due to pressure drops, were estimated and the payback periods for the mentioned evaporative inlet cooling methods were obtained and compared. The suitable evaporative cooling method for various operational conditions is proposed for 25 MW Fiat gas turbines.

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