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.

Performance Improvement of a Simple Gas Turbine Power Station Using Pulse Combustion Technology

2004 ◽  
Author(s):  
Mohamed A. Gadalla
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pressure Ratio ◽  
Combustion Process ◽  
Pressure Rise ◽  
Operating Conditions ◽  
Maximum Pressure ◽  
Air Cooling ◽  
Pulse Combustion ◽  
Gas Turbine Cycle

The retrofitting projects have been considered in many countries to convert simple gas turbine units into more advanced cycle units with higher efficiency and higher output. Among many proven technologies, such as inlet air cooling, intercooling, regeneration, reheat and steam injection gas turbine etc., pulse combustion is one of the promising technologies in boosting both the output capacity and thermal efficiency, and reducing carbon and nitrogen oxides emissions without additional pollution control equipment. This paper presents the analysis of potential and real benefits of pulse combistion technology applied in the combustion process of a simple gas turbine cycle under different operating conditions. In addition, this study investigates the utilization of converting part of chemical energy of fuel into pressure energy in the gas turbine pulse combustion chamber. The influence of the maximum pressure rise due to pulse combustion (pre-compression parameter), the ratio of combustion heat released in the isochoric process, maximum cycle temperature, and compressor pressure ratio on the performance paramenters such as net work output, cycle thermal efficiency, and fuel consumption were also investigated. Finally, the results of comparative analyses between a simple gas turbine cycle utilizing a pulse combustor and a conventional cycle show the thermodynamic advantages of applying this technology in simple gas turbine power cycles.

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.

Performance improvements of the recuperated gas turbine cycle using absorption inlet cooling and evaporative aftercooling

2002 ◽  
Vol 216 (4) ◽  
pp. 295-306 ◽  
Author(s):  
A. M. Bassily
Keyword(s):  
Gas Turbine ◽  
Parametric Study ◽  
Cooling System ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Temperature Ratio ◽  
Optimum Pressure ◽  
Performance Improvements ◽  
Gas Turbine Cycle ◽  
The Impact

An absorption inlet cooling system is introduced into the recuperated gas turbine cycle. The exhaust gases of the cycle are used to run the system. Five different layouts of the recuperated gas turbine cycle are presented. These include the effects of absorption inlet cooling, evaporative inlet cooling and evaporative cooling of compressor discharge (evaporative aftercooling), and the combined effect of absorption inlet cooling and evaporative aftercooling. A parametric study of the effect of pressure ratio, ambient temperature and relative humidity on the performance of all cycles is carried out. The results indicate that absorption inlet cooling could increase the efficiency of the recuperated cycle by up to 4 per cent, compared with 2.2 per cent for evaporative inlet cooling. Absorption inlet cooling with evaporative aftercooling could increase the optimum per efficiency of the recuperated cycle by up to 5 per cent and its maximum power by up to 65 per cent. Evaporative aftercooling reduces the impact of inlet cooling. Another parametric study of the effect of the turbine compressor inlet temperature ratio on the optimum pressure ratios indicated that cycles with evaporative aftercooling have higher optimum pressure ratios, which could be a function of the inlet temperature ratio and air temperature at the compressor outlet.

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.

Performance Simulation of a Combined Cycle Power Generation System With Steam Injection in the Gas Turbine Combustion Chamber

2007 ◽  
Author(s):  
B. Law ◽  
B. V. Reddy
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pressure Ratio ◽  
Steam Injection ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Work Output ◽  
Gas Turbine Combustion

In the present work the effect of steam injection in the gas turbine combustion chamber is investigated on gas turbine and steam turbine work output and on thermal efficiency of the combined cycle power plant. The operating conditions investigated include gas turbine pressure ratio and gas turbine inlet temperature. The steam injection decreases the steam cycle output and boosts the gas cycle output and the net combined cycle work output and thermal efficiency significantly.

Proposal of Innovative Gas Turbine Combined Cycle Power Generation System

2004 ◽  
Author(s):  
Hideto Moritsuka
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Generation System ◽  
Turbine Inlet Temperature ◽  
Turbine Inlet ◽  
Power Generation System

In order to estimate the possibility to improve thermal efficiency of power generation use gas turbine combined cycle power generation system, benefits of employing the advanced gas turbine technologies proposed here have been made clear based on the recently developed 1500C-class steam cooling gas turbine and 1300C-class reheat cycle gas turbine combined cycle power generation systems. In addition, methane reforming cooling method and NO reducing catalytic reheater are proposed. Based on these findings, the Maximized efficiency Optimized Reheat cycle Innovative Gas Turbine Combined cycle (MORITC) Power Generation System with the most effective combination of advanced technologies and the new devices have been proposed. In case of the proposed reheat cycle gas turbine with pressure ratio being 55, the high pressure turbine inlet temperature being 1700C, the low pressure turbine inlet temperature being 800C, combined with the ultra super critical pressure, double reheat type heat recovery Rankine cycle, the thermal efficiency of combined cycle are expected approximately 66.7% (LHV, generator end).

High-Temperature Potential of Uncooled Radial Turbines

1978 ◽  
Vol 100 (2) ◽  
pp. 294-302 ◽  
Author(s):  
D. J. Arnold ◽  
O. E. Balje
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Experimental Investigations ◽  
Inlet Temperature ◽  
High Reaction ◽  
Temperature Potential ◽  
Axial Turbines ◽  
Radial Turbines

Radial turbines are used predominantly for turbo-charges where the geometry is frequently compromised to favor low fabrications costs. Theoretical as well as experimental investigations have shown that the efficiency potential of radial turbines is as high as the efficiency potential of high reaction axial turbines. Structural and heat transfer studies on radial turbines show that the highest stresses in “deep scalloped” radial rotors occur at locations where the metal temperature is considerably lower than at rotor inlet. Thus the maximum allowable gas inlet temperature for radial turbines is several hundred degrees higher than for high-reaction axial turbines. This difference tends to increase with increasing expansion ratios, at least up to expansion ratios of 10:1. Since the thermal efficiency of typical gas turbine cycles increases with increasing gas temperatures and increasing expansion ratios, it results that the application of uncooled radial turbines will yield cycle efficiencies which are not obtainable with uncooled axial turbines.

scholarly journals Efficiency Analysis of the Turbine using Calorific Value Parameters for a 10 Megawatt Gas Turbine

2021 ◽  
pp. 59-66
Author(s):  
Rex K.C Amadi ◽  
Charles David
Keyword(s):  
Ambient Temperature ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pressure Ratio ◽  
Calorific Value ◽  
Operating Conditions ◽  
Outlet Temperature ◽  
Flow Process ◽  
Compressor Work ◽  
Gas Turbine Power Plant

This research is based on the thermodynamic performance of a gas turbine power plant.  It considered the variation of operating conditions, i.e. the ambient temperature, the compressor outlet temperature, pressure ratio, etc. on the performance of the gas turbine thermal efficiency, turbine work, compressor work, etc. which were derived and analyzed.  The Gross (higher) calorific values at constant pressure () heat of combustion in a flow process from state 1 to state 2 was considered and used to analyze our thermal efficiency.  The results show that the ambient temperature and air to fuel ratio strongly influence the turbine work, compressor work and thermal efficiency.  In addition, the thermal efficiency and power decreases linearly with increase of the ambient temperature.  However, the efficiency analyzed when the calorific parameters were considered was higher than the efficiency when the basic thermodynamic theories (first and second law principles) were used.  The first ranges between 31% to 33, while the second ranges between 28% to 32% under the same ambient temperature conditions

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.

Disappearing Thermo-Economic Sanity in Gas Turbine Combined Cycle Ratings: A Critique

2019 ◽  
Author(s):  
S. Can Gülen
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Film Cooling ◽  
Pressure Ratio ◽  
Open Loop ◽  
Product Line ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Turbine Inlet ◽  
Steam Turbine Condenser

Abstract There is very little doubt that there has been a noticeable advance in heavy-duty industrial gas turbine technology for utility scale electric power generation in the last decade. In keeping with the first six decades of the technology (roughly 1950 through 2010), the main drivers in increasing thermal efficiency and megawatt ratings have been increasing turbine inlet temperature and airflow. In accordance with the basic thermodynamic principles governing the underlying Brayton cycle, compressor pressure ratio kept pace with them. It is hard to quibble about the 40+ percent in rated thermal efficiency in simple cycle. If projected turbine inlet temperatures and cycle pressure ratios can be sustained in the field, current state-of-the-art in turbine hot gas path metallurgy, coatings and advanced film cooling techniques indeed support published ratings. Unfortunately, published combined cycle ratings are an altogether different matter. It is one thing to set the product line rating performance at an aggressive level with well-understood albeit optimistic assumptions such as very low water-cooled steam turbine condenser pressure with open-loop cooling. It is yet another thing to blatantly disregard fundamental laws of thermodynamics with outlandish performance ratings, which are unlikely to materialize even in the next decade or two cost-effectively (unless an unforeseen transformative step-change in technology materializes). In this paper, using fundamental thermodynamic arguments and detailed heat and mass balance simulations, it will be shown that some, if not all, OEM ratings are losing touch with reality.

Sign in / Sign up

Export Citation Format

Share Document