Gas Turbine Evaporative Cooling, A Novel Method for Combined Cycle Plant Part Load Optimization

2021 ◽  
Author(s):  
Jose Carmona
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Evaporative Cooling ◽  
Heat Rate ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Part Load ◽  
Load Optimization ◽  
Water Ratio ◽  
Steam Production

Abstract In power plant engineering, gas turbine (GT) evaporative cooling is traditionally thought as one of the few power augmentation alternatives for existing plants. For most combined cycle plants operating at part load, the GT Inlet Guide Vanes (IGV) will throttle the air flow to the combustor to maintain the turbine exhaust temperature (TET) as high as possible, thus maximizing the overall combined cycle efficiency. The IGV air throttling results in a reduction of the turbine inlet air temperature (TIT) due to a reduction on the mass of fuel burned in the combustors as the available combustion air decreases due to IGV throttling to maintain an optimum air to fuel ratio, resulting on a lower TET compared with the same GT at base load. The compounded result of these effects limits the maximum steam production capacity on the heat recovery steam generator, particularly for the high-pressure section, hampering the efficiency of the steam turbine. The methodology developed in the subject study aims at counteracting the afore-mentioned effects by optimizing the evaporative cooler air/water ratio which results in the lower possible heat rate for full load and part load operation. By dynamically controlling the air/water ratio, a preheating effect can be achieved in the compressor inlet air, which results on higher exhaust gas temperature, thus augmenting the high-pressure steam production on the heat recovery steam generator and accordingly the steam turbine efficiency. For a newly built 907 MWe Combined Cycle Gas Turbine (CCGT) plant, application of the evaporative cooling part load optimization methodology presented in this study could lead to a potential reduction of up to 158kJ/kWh on heat rate and 9.318 g/kWh of CO2 emissions if compared with the same plant without dynamic control of the evaporative cooler air/water ratio.

Gas Turbine Evaporative Cooling: A Novel Method for Combined Cycle Plant Part Load Optimization

2020 ◽  
Author(s):  
Jose Carmona
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Evaporative Cooling ◽  
Heat Rate ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Part Load ◽  
Load Optimization ◽  
Water Ratio ◽  
Steam Production

Abstract In power plant engineering, gas turbine (GT) evaporative cooling is traditionally thought as one of the few power augmentation alternatives for existing plants. For most combined cycle plants operating at part load, the GT Inlet Guide Vanes (IGV) will throttle the air flow to the combustor to maintain the turbine exhaust temperature (TET) as high as possible, thus maximizing the overall combined cycle efficiency. The IGV air throttling results in a reduction of the turbine inlet air temperature (TIT) due to a reduction on the mass of fuel burned in the combustors as the available combustion air decreases due to IGV throttling to maintain an optimum air to fuel ratio, resulting on a lower TET compared with the same GT at base load. The compounded result of these effects limits the maximum steam production capacity on the heat recovery steam generator, particularly for the high-pressure section, hampering the efficiency of the steam turbine. The methodology developed in the subject study aims at counteracting the afore-mentioned effects by optimizing the evaporative cooler air/water ratio which results in the lower possible heat rate for full load and part load operation. By dynamically controlling the air/water ratio, a preheating effect can be achieved in the compressor inlet air, which results on higher exhaust gas temperature, thus augmenting the high-pressure steam production on the heat recovery steam generator and accordingly the steam turbine efficiency. For a newly built 907 MWe Combined Cycle Gas Turbine (CCGT) plant, application of the evaporative cooling part load optimization methodology presented in this study could lead to a potential reduction of up to 158kJ/kWh on heat rate and 9.318 g/kWh of CO2 emissions if compared with the same plant without dynamic control of the evaporative cooler air/water ratio.

LM2500+ Single Shaft Combined Cycle With Frequency Stabilization

1998 ◽  
Author(s):  
Donald A. Kolp ◽  
Charles E. Levey
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Heat Recovery ◽  
Heat Rate ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Equipment Operation ◽  
Combined Cycle Plant ◽  
Stable Frequency ◽  
And Performance

Zorlu Enerji needed 35 MW of reliable power at a stable frequency to maintain constant speed on the spindles producing thread at its parent company’s textile plant in Bursa, Turkey. In December of 1996, Zorlu selected an LM2500+ combined cycle plant to fill its power-generating requirements. The LM2500+ has output of 26,810 KW at a heat rate of 9,735 Kj/Kwh. The combined cycle plant has an output of 35,165 KW and a heat rate of 7,428 Kj/Kwh. The plant operates in the simple cycle mode utilizing the LM2500+ and a bypass stack and in combined cycle mode using the 2-pressure heat recovery steam generator and single admission, 9.5 MW condensing steam turbine. The generator is driven through a clutch by the steam turbine from the exciter end and by the gas turbine from the opposing end. The primary fuel for the plant is natural gas; the backup fuel is naphtha. Utilizing a load bank, the plant is capable of accepting a 12 MW load loss when the utility breaker trips open; it can sustain this loss while maintaining frequency within 1% on the mill load. The frequency stabilizing capability prevents overspeeding of the spindles, breakage of thousands of strands of thread and a costly shutdown of the mill. A description of the equipment, operation and performance illustrates the unique features of this versatile, compact and efficient generating unit.

scholarly journals Gas Turbine Heat Recovery Steam Generators for Combined Cycles Natural or Forced Circulation Considerations

1988 ◽  
Author(s):  
Akber Pasha
Keyword(s):  
Gas Turbine ◽  
Steam Generator ◽  
Heat Recovery ◽  
Power Plants ◽  
Natural Circulation ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Steam Generators ◽  
Forced Circulation ◽  
Gas Turbine Exhaust

In recent years the combined cycle has become a very attractive power plant arrangement because of its high cycle efficiency, short order-to-on-line time and flexibility in the sizing when compared to conventional steam power plants. However, optimization of the cycle and selection of combined cycle equipment has become more complex because the three major components, Gas Turbine, Heat Recovery Steam Generator and Steam Turbine, are often designed and built by different manufacturers. Heat Recovery Steam Generators are classified into two major categories — 1) Natural Circulation and 2) Forced Circulation. Both circulation designs have certain advantages, disadvantages and limitations. This paper analyzes various factors including; availability, start-up, gas turbine exhaust conditions, reliability, space requirements, etc., which are affected by the type of circulation and which in turn affect the design, price and performance of the Heat Recovery Steam Generator. Modern trends around the world are discussed and conclusions are drawn as to the best type of circulation for a Heat Recovery Steam Generator for combined cycle application.

Gas Turbine Combined Cycle Optimized for Postcombustion Carbon Capture

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
S. Can Gülen ◽  
Chris Hall
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Co2 Capture ◽  
Carbon Capture ◽  
Heat Recovery ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Gas Temperature ◽  
Design Challenges ◽  
Stack Gas

This paper describes a gas turbine combined cycle (GTCC) power plant system, which addresses the three key design challenges of postcombustion CO2 capture from the stack gas of a GTCC power plant using aqueous amine-based scrubbing method by offering the following: (i) low heat recovery steam generator (HRSG) stack gas temperature, (ii) increased HRSG stack gas CO2 content, and (iii) decreased HRSG stack gas O2 content. This is achieved by combining two bottoming cycle modifications in an inventive manner, i.e., (i) high supplementary (duct) firing in the HRSG and (ii) recirculation of the HRSG stack gas. It is shown that, compared to an existing natural gas-fired GTCC power plant with postcombustion capture, it is possible to reduce the CO2 capture penalty—power diverted away from generation—by almost 65% and the overall capital cost ($/kW) by about 35%.

HRSG Duct Firing Revisited

2018 ◽  
Author(s):  
S. Can Gülen
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Fossil Fuel ◽  
Heat Rate ◽  
Combined Cycle ◽  
Efficiency Improvement ◽  
Combined Cycle Power Plant

Duct firing in the heat recovery steam generator (HRSG) of a gas turbine combined cycle power plant is a commonly used method to increase output on hot summer days when gas turbine airflow and power output lapse significantly. The aim is to generate maximum possible power output when it is most needed (and, thus, more profitable) at the expense of power plant heat rate. In this paper, using fundamental thermodynamic arguments and detailed heat and mass balance simulations, it will be shown that, under certain boundary conditions, duct firing in the HRSG can be a facilitator of efficiency improvement as well. When combined with highly-efficient aeroderivative gas turbines with high cycle pressure ratios and concomitantly low exhaust temperatures, duct firing can be utilized for small but efficient combined cycle power plant designs as well as more efficient hot-day power augmentation. This opens the door to efficient and agile fossil fuel-fired power generation opportunities to support variable renewable generation.

scholarly journals Performance Analysis of Combined Cycle with Air Breathing Derivative Gas Turbine, Heat Recovery Steam Generator, and Steam Turbine as LNG Tanker Main Engine Propulsion System

2020 ◽  
Vol 8 (9) ◽  
pp. 726
Author(s):  
Wahyu Nirbito ◽  
Muhammad Arif Budiyanto ◽  
Robby Muliadi
Keyword(s):  
Performance Analysis ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Steam Generator ◽  
Heat Recovery ◽  
Combined Cycle ◽  
Propulsion System ◽  
Heat Recovery Steam Generator ◽  
Main Engine ◽  
Ship Speed

This study explains the performance analysis of a propulsion system engine of an LNG tanker using a combined cycle whose components are gas turbine, steam turbine, and heat recovery steam generator. The researches are to determine the total resistance of an LNG tanker with a capacity of 125,000 m3 by using the Maxsurf Resistance 20 software, as well as to design the propulsion system to meet the required power from the resistance by using the Cycle-Tempo 5.0 software. The simulation results indicate a maximum power of the system of about 28,122.23 kW with a fuel consumption of about 1.173 kg/s and a system efficiency of about 48.49% in fully loaded conditions. The ship speed can reach up to 20.67 knots.

scholarly journals Optimization of Gas Turbine HRSG Cycles Some Concepts

1991 ◽  
Author(s):  
Akber Pasha
Keyword(s):  
Gas Turbine ◽  
Steam Generator ◽  
Heat Recovery ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Recent Developments ◽  
Overall Efficiency ◽  
Total Performance

Today the Heat Recovery Steam Generator (HRSG) has become an integral part of the combined cycle or Cogen plant because of its influence on other equipment. Therefore, the optimization of the HRSG has become one of the prime targets to improve the overall efficiency. The paper presents recent developments and concepts used in HRSG design which improve either the efficiency or the range of performance or both. The paper discusses three major areas of a HRSG - Superheater/Reheater, Economizer, and LP Evaporator/Feedwater Preheater. Depending upon the requirement, the user can implement one or more of the concepts to improve the total performance and/or the reliability.

scholarly journals Repowering of a Small Utility: A Unique Solution to a Unique Problem

1979 ◽  
Author(s):  
L. F. Fougere ◽  
H. G. Stewart ◽  
J. Bell
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Steam Generator ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Electric Utility ◽  
Combined Cycle ◽  
Steam Boiler ◽  
Heat Recovery Steam Generator ◽  
Turbine Generator

Citizens Utilities Company’s Kauai Electric Division is the electric utility on the Island of Kauai, fourth largest and westernmost as well as northernmost of the Hawaiian Islands. As a result of growing load requirements, additional generating capacity was required that would afford a high level of reliability and operating flexibility and good fuel economy at reasonable capital investment. To meet these requirements, a combined cycle arrangement was completed in 1978 utilizing one existing gas turbine-generator and one new gas turbine-generator, both exhausting to a new heat recovery steam generator which supplies steam to an existing steam turbine-generator. Damper controlled ducting directs exhaust gas from either gas turbine, one at a time, through the heat recovery steam generator. The existing oil-fired steam boiler remains available to power the steam turbine-generator independently or in parallel with the heat recovery steam generator. The gas turbines can operate either in simple cycle as peaking units or in combined cycle, one at a time, as base load units. This arrangement provides excellent operating reliability and flexibility, and the most favorable economics of all generating arrangements for the service required.

scholarly journals Thermodynamic and economic analysis of a gas turbine combined cycle plant with oxy-combustion

2013 ◽  
Vol 34 (4) ◽  
pp. 215-233 ◽  
Author(s):  
Janusz Kotowicz ◽  
Marcin Job
Keyword(s):  
Carbon Dioxide ◽  
Genetic Algorithm ◽  
Gas Turbine ◽  
Heat Recovery ◽  
Carbon Dioxide Capture ◽  
Combined Cycle ◽  
Operating Parameters ◽  
Economic Factors ◽  
Heat Recovery Steam Generator ◽  
Combined Cycle Plant

Abstract This paper presents a gas turbine combined cycle plant with oxy-combustion and carbon dioxide capture. A gas turbine part of the unit with the operating parameters is presented. The methodology and results of optimization by the means of a genetic algorithm for the steam parts in three variants of the plant are shown. The variants of the plant differ by the heat recovery steam generator (HRSG) construction: the singlepressure HRSG (1P), the double-pressure HRSG with reheating (2PR), and the triple-pressure HRSG with reheating (3PR). For obtained results in all variants an economic evaluation was performed. The break-even prices of electricity were determined and the sensitivity analysis to the most significant economic factors were performed.

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