Comparative Analysis of Off-Design Performance Characteristics of Single and Two Shaft Industrial Gas Turbines

2002 ◽  
Author(s):  
J. H. Kim ◽  
T. S. Kim ◽  
J. L. Sohn ◽  
S. T. Ro
Keyword(s):  
Gas Turbines ◽  
Combined Cycle ◽  
Performance Characteristics ◽  
Cycle Performance ◽  
Operating Characteristics ◽  
Exhaust Temperature ◽  
Operating Modes ◽  
Recovery Capacity ◽  
Industrial Gas Turbines ◽  
Component Models

Off-design steady performance and operating characteristics of single and two shaft gas turbines for electric power generation have been investigated comparatively. A set of balance equations has been derived based on validated component models. A simultaneous calculation scheme has been employed, which is flexible to various engine configurations. Part-load performance analyses of two commercial gas turbines have been carried out to compare operating characteristics between single and two shaft engines. The predicted performance characteristics of both engines coincide soundly with the manufacturer’s data and also correspond with the inherent characteristics of each configuration. The adoption of the VIGV modulation has been addressed in order to examine the possibility of leveling up the heat recovery capacity by maintaining a high turbine exhaust temperature (TET) when those gas turbines are used for combined cycle plants. Maintaining TET at its design value as far as the VIGV modulation allows has been simulated and it has been determined that the TET control is possible at up to 40% and 50% load in the single and two shaft engine, respectively. Combined cycle performances have also been investigated for two engine configurations in different operating modes. While the VIGV modulation produces a favorable influence over the combined cycle performance of the single shaft configuration, the two shaft engine does not appear to be effectively improved by the VIGV modulation since the degradation of gas turbine performance counteracts the advantage of the higher performance of the bottoming (steam turbine) cycle.

scholarly journals Pressure gain combustion advantage in land-based electric power generation

2017 ◽  
Vol 1 ◽  
pp. K4MD26 ◽  
Author(s):  
Seyfettin C. Gülen
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Heavy Duty ◽  
Quantum Leap ◽  
Pressure Gain Combustion ◽  
Industrial Gas Turbines ◽  
Plant Efficiency

AbstractThis article evaluates the improvement in gas turbine combined cycle power plant efficiency and output via pressure gain combustion (PGC). Ideal and real cycle calculations are provided for a rigorous assessment of PGC variants (e.g., detonation and deflagration) in a realistic power plant framework with advanced heavy-duty industrial gas turbines. It is shown that PGC is the single-most potent knob available to the designers for a quantum leap in combined cycle performance.

A Fifty Percent Plus Efficiency Mid Range Advanced Cheng Cycle

2002 ◽  
Author(s):  
Albert L. C. Nelson ◽  
Vahid Vaezi ◽  
Dah Yu Cheng
Keyword(s):  
Energy Balance ◽  
Gas Turbines ◽  
High Efficiency ◽  
Combined Cycle ◽  
Performance Characteristics ◽  
Simple Cycle ◽  
Cycle Performance ◽  
Heat Recovery Boiler ◽  
Inlet Temperature ◽  
Variable Load

Cheng Power Systems, Inc. following the successful Cheng Cycle development based on the Allison 501KH, is developing a 50%+ efficiency medium-power-range Advanced Cheng Cycle. The recent development work involved the selection of a candidate gas turbine which possesses the following attributes: (1) a single shaft, (2) advanced compressor and turbine aerodynamic design, and (3) F-Class firing temperature. The targeted results were a 30MW+ output and 50%+ efficient intermediate-load Advanced Cheng Cycle with the simple-cycle performance characteristics of quick startup and shutdown and a $/kW cost comparable to simple-cycle machines, but at a combined-cycle efficiency. A candidate engine was selected which has the following performance characteristics: a compressor pressure ratio of 18:1, a turbine inlet temperature of 1250°C, and a net efficiency of 35%. Cheng Power has a unique software program which predicts the energy balance at various ambient conditions. The program takes into account the massive cooling air flows incorporated into advanced gas turbines and the heat recovery boiler performance characteristics when developing our performance analyses. The uniqueness of the Cheng Cycle is that it selects a trajectory of steam-to-air ratios to maintain high efficiency for the entire operating range of the power system, while offering competitive efficiency, simple hardware, the possibility of retrofit, fast response to load change, and feasible cogeneration plant operations. The quick startup of the Advanced Cheng Cycle is suitable for variable load operation in the mid range, i.e. 8 to 10 hours per day. This paper provides the energy balance of the proposed plant and its variation with ambient temperature. The paper also addresses the emission characteristics of this engine, which provides low NOx and CO emissions at levels that satisfy most U.S. EPA requirements without SCR or any other add-on devices.

The Design and Development of an Electrically Operated Fuel Control Valve for Industrial Gas Turbines

1991 ◽  
Author(s):  
A. G. Salsi ◽  
F. S. Bhinder
Keyword(s):  
Gas Turbines ◽  
Entire Range ◽  
Control Valve ◽  
Performance Characteristics ◽  
Design And Development ◽  
Wide Range ◽  
Industrial Gas Turbines

Industrial gas turbines operate over a wide range of combinations of loads and speeds. The fuel control valve must be designed to cover the entire range precisely. The design of an electrically operated fuel control valve is described and comparison between the predicted and measured performance characteristics is shown.

7H™ Combustion System Performance With Fuel Moisturization

2006 ◽  
Author(s):  
Markus Feigl ◽  
Geoff Myers ◽  
Stephen R. Thomas ◽  
Raub Smith
Keyword(s):  
Gas Turbines ◽  
Combined Cycle ◽  
Combustion System ◽  
Heavy Duty ◽  
Single Digit ◽  
Efficiency Performance ◽  
Industrial Gas Turbines ◽  
Industrial Gas Turbine ◽  
Cycle Efficiency ◽  
Full Pressure

This paper describes the concept and benefits of the fuel moisturization system for the GE H System™ steam-cooled industrial gas turbine. The DLN2.5H combustion system and fuel moisturization system are both described, along with the influence of fuel moisture on combustor performance as measured during full-scale, full-pressure rig testing of the DLN2.5H combustion system. The lean, premixed DLN2.5H combustion system was targeted to deliver single-digit NOx and CO emissions from 40% to 100% combined cycle load in both the Frame 7H (60 Hz) and Frame 9H (50 Hz) heavy-duty industrial gas turbines. These machines are also designed to yield a potential combined-cycle efficiency of 60 percent or higher. Fuel moisturization contributes to the attainment of both the NOx and the combined-cycle efficiency performance goals, as discussed in this paper.

Solar Hybrid Combined Cycle Performance Prediction: Influence of GT Model and Spool Arrangement

2012 ◽  
Author(s):  
G. Barigozzi ◽  
G. Bonetti ◽  
G. Franchini ◽  
A. Perdichizzi ◽  
S. Ravelli
Keyword(s):  
Gas Turbine ◽  
Performance Prediction ◽  
Gas Turbines ◽  
Control Strategies ◽  
Rankine Cycle ◽  
Simulation Method ◽  
Power Input ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Solar Field

A modeling procedure was developed to simulate design and off-design operation of Hybrid Solar Gas Turbines in a combined cycle (CC) configuration. The system includes an heliostat field, a receiver and a commercial gas turbine interfaced with a conventional steam Rankine cycle. Solar power input is integrated in the GT combustor by natural gas. Advanced commercial software tools were combined together to get design and off-design performance prediction: TRNSYS® was used to model the solar field and the receiver while the gas turbine and steam cycle simulations were performed by means of Thermoflex®. Three GT models were considered, in the 35–45 MWe range: a single shaft engine (Siemens SGT800) and two two-shaft engines (the heavy-duty GT Siemens SGT750 and the aero derivative GE LM6000 PF). This in order to assess the influence of different GT spool arrangements and control strategies on GT solarization. The simulation method provided an accurate modeling of the daily solar hybrid CC behavior to be compared against the standard CC. The effects of solarization were estimated in terms of electric power and efficiency reduction, fossil fuel saving and solar energy to electricity conversion efficiency.

Comparison of Externally Fired and Internal Combustion Gas Turbines Using Biomass Fuel

2001 ◽  
Vol 123 (4) ◽  
pp. 291-296 ◽  
Author(s):  
Sandro B. Ferreira ◽  
Pericles Pilidis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
Internal Combustion ◽  
Combined Cycle ◽  
Maintenance Cost ◽  
Combustion Gas ◽  
Exhaust Temperature ◽  
Exergetic Analysis ◽  
Main Components

There is a difference of opinion regarding the relative merits of gas turbines using biomass fuels. Some engineers believe that the internal combustion gas turbine coupled to a gasifier will give a higher efficiency than the externally fired gas turbine using pretreated biomass that is not gasified. Others believe the opposite. In this paper, a comparison between these schemes is made, within the framework of the Brazilian perspective. The exergetic analysis of four cycles is described. The first cycle is externally fired (EFGT), the second uses gasified biomass as fuel (BIG/GT), each of them with a combined cycle as a variant (EFGT/CC and BIG/GTCC). These four are then compared to the natural gas turbine cycles (NGT and NGT/CC) in order to evaluate the thermodynamic cost of using biomass. The comparison is carried out in terms of thermal efficiency and in terms of exergetic efficiency and exergy destruction in the main components. The present analysis shows that the EFGT is quite promising. When compared to the NGT cycle, the EFGT gas turbine shows poor efficiency, though this parameter practically equals that of the BIG/GT cycle. The use of a bottoming steam cycle changes the figures, and the EFGT/CC—due to its higher exhaust temperature—results in high efficiency compared to the BIG/GTCC. Its lower initial and maintenance cost may be an important attraction.

Study of Humid Air Gas Turbine System by Experiment and Analysis

2011 ◽  
Author(s):  
Toru Takahashi ◽  
Yutaka Watanabe ◽  
Hidefumi Araki ◽  
Takashi Eta
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pilot Plant ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Medium Size ◽  
Water Recovery ◽  
Two Stage ◽  
Humid Air

Humid air gas turbine systems that are regenerative cycle using humidified air can achieve higher thermal efficiency than gas turbine combined cycle power plant (GTCC) even though they do not require a steam turbine, a high combustion temperature, or a high pressure ratio. In particular, the advanced humid air gas turbine (AHAT) system appears to be highly suitable for practical use because its composition is simpler than that of other systems. Moreover, the difference in thermal efficiency between AHAT and GTCC is greater for small and medium-size gas turbines. To verify the system concept and the cycle performance of the AHAT system, a 3MW-class pilot plant was constructed that consists of a gas turbine with a two-stage centrifugal compressor, a two-stage axial turbine, a reverse-flow-type single-can combustor, a recuperator, a humidification tower, a water recovery tower, and other components. As a result of an operation test, the planned power output of 3.6MW was achieved, so that it has been confirmed the feasibility of the AHAT as a power-generating system. In this study, running tests on the AHAT pilot plant is carried out over one year, and various characteristics such as the effect of changes in ambient temperature, part-load characteristics, and start-up characteristics were clarified by analyzing the data obtained from the running tests.

Gas Turbine Airflow Control for Optimum Heat Recovery

1983 ◽  
Vol 105 (1) ◽  
pp. 72-79 ◽  
Author(s):  
W. I. Rowen ◽  
R. L. Van Housen
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Guide Vane ◽  
Control Mode ◽  
Cycle Performance ◽  
Inlet Guide Vane ◽  
Part Load ◽  
Exhaust Temperature ◽  
Cycle Efficiency

Gas turbines furnished with heat recovery equipment generally have maximum cycle efficiency when the gas turbine is operated at its ambient capability. At reduced gas turbine output the cycle performance can fall off rapidly as gas turbine exhaust temperature drops, which reduces the heat recovery equipment performance. This paper reviews the economic gains which can be realized through use of several control modes which are currently available to optimize the cycle efficiency at part load operation. These include variable inlet guide vane (VIGV) control for single-shaft units, and combined VIGV and variable high-pressure set (compressor) speed control for two-shaft units. In addition to the normal control optimization mode to maintain the maximum exhaust temperature, a new control mode is discussed which allows airflow to be modulated in response to a process signal while at constant part load. This control feature is desirable for gas turbines which supply preheated combustion air to fired process heaters.

Dry, Low Emissions for the ‘H’ Heavy-Duty Industrial Gas Turbines: Full-Scale Combustion System Rig Test Results

2003 ◽  
Author(s):  
Geoff Myers ◽  
Dan Tegel ◽  
Markus Feigl ◽  
Fred Setzer ◽  
William Bechtel ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Full Scale ◽  
Combustion System ◽  
Heavy Duty ◽  
Test Program ◽  
Industrial Gas Turbines ◽  
Inlet Conditions

The lean, premixed DLN2.5H combustion system was designed to deliver low NOx emissions from 50% to 100% load in both the Frame 7H (60 Hz) and Frame 9H (50 Hz) heavy-duty industrial gas turbines. The H machines employ steam cooling in the gas turbine, a 23:1 pressure ratio, and are fired at 1440 C (2600 F) to deliver over-all thermal efficiency for the combined-cycle system near 60%. The DLN2.5H combustor is a modular can-type design, with 14 identical chambers used on the 9H machine, and 12 used on the smaller 7H. On a 9H combined-cycle power plant, both the gas turbine and steam turbine are fired using the 14-chamber DLN2.5H combustion system. An extensive full-scale, full-pressure rig test program developed the fuel-staged dry, low emissions combustion system over a period of more than five years. Rig testing required test stand inlet conditions of over 50 kg/s at 500 C and 28 bar, while firing at up to 1440 C, to simulate combustor operation at base load. The combustion test rig simulated gas path geometry from the discharge of the annular tri-passage diffuser through the can-type combustion liner and transition piece, to the inlet of the first stage turbine nozzle. The present paper describes the combustion system, and reports emissions performance and operability results over the gas turbine load and ambient temperature operating range, as measured during the rig test program.

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