HRSG Duct Firing Revisited

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.

Volume 2: Controls, Diagnostics and Instrumentation; Cycle Innovations; Electric Power ◽

Second Law Efficiency of the Rankine Bottoming Cycle of a Combined Cycle Power Plant

10.1115/gt2008-51381 ◽

2008 ◽

Cited By ~ 1

Author(s):

S. Can Gulen ◽

Raub W. Smith

Keyword(s):

Power Plant ◽

Gas Turbine ◽

Power Output ◽

Gas Turbines ◽

Power Plants ◽

Combined Cycle ◽

Cycle Performance ◽

Second Law ◽

Modeling Tools ◽

A significant portion of the new electrical generating capacity installed in the past decade has employed heavy-duty gas turbines operating in a combined cycle configuration with a steam turbine bottoming cycle. In these power plants approximately one third of the power is generated by the bottoming cycle. To ensure that the highest possible combined cycle efficiency is realized it is important to develop the combined cycle power plant as a system. Doing so requires a solid understanding of the efficiency entitlement of both, topping and bottoming, cycles separately and as a whole. This paper describes a simple but accurate method to estimate the Rankine bottoming cycle power output directly from the gas turbine exhaust exergy utilizing the second law of thermodynamics. The classical first law approach, i.e. the heat and mass balance method, requires lengthy calculations and complex computer-based modeling tools to evaluate Rankine bottoming cycle performance. In this paper, a rigorous application of the fundamental thermodynamic principles embodied by the second law to the major cycle components clearly demonstrates that the Rankine cycle performance can be accurately represented by several key parameters. The power of the second law approach lies in its ability to highlight the theoretical entitlement and state-of-the-art design performances simultaneously via simple, fundamental relationships. By considering economically and technologically feasible upper limits for the key parameters, the maximum achievable bottoming cycle power output is readily calculable for any given gas turbine from its exhaust exergy.

Second Law Efficiency of the Rankine Bottoming Cycle of a Combined Cycle Power Plant

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.3124787 ◽

2009 ◽

Vol 132 (1) ◽

Cited By ~ 14

Author(s):

S. Can Gülen ◽

Raub W. Smith

Keyword(s):

Power Plant ◽

Gas Turbine ◽

Power Output ◽

Gas Turbines ◽

Power Plants ◽

Combined Cycle ◽

Cycle Performance ◽

Second Law ◽

Modeling Tools ◽

A significant portion of the new electrical generating capacity installed in the past decade has employed heavy-duty gas turbines operating in a combined cycle configuration with a steam turbine bottoming cycle. In these power plants approximately one-third of the power is generated by the bottoming cycle. To ensure that the highest possible combined cycle efficiency is realized it is important to develop the combined cycle power plant as a system. Doing so requires a solid understanding of the efficiency entitlement of both, topping and bottoming, cycles separately and as a whole. This paper describes a simple but accurate method to estimate the Rankine bottoming cycle power output directly from the gas turbine exhaust exergy, utilizing the second law of thermodynamics. The classical first law approach, i.e., the heat and mass balance method, requires lengthy calculations and complex computer-based modeling tools to evaluate Rankine bottoming cycle performance. In this paper, a rigorous application of the fundamental thermodynamic principles embodied by the second law to the major cycle components clearly demonstrates that the Rankine cycle performance can be accurately represented by several key parameters. The power of the second law approach lies in its ability to highlight the theoretical entitlement and state-of-the-art design performances simultaneously via simple fundamental relationships. By considering economically and technologically feasible upper limits for the key parameters, the maximum achievable bottoming cycle power output is readily calculable for any given gas turbine from its exhaust exergy.

Upgraded M501G Operating Experience

Volume 5: Turbo Expo 2005 ◽

10.1115/gt2005-69135 ◽

2005 ◽

Author(s):

H. Arimura ◽

Y. Iwasaki ◽

Y. Fukuizumi ◽

S. Shiozaki ◽

V. Kallianpur

Keyword(s):

Power Plant ◽

Gas Turbine ◽

Gas Turbines ◽

Operating Experience ◽

Heat Rate ◽

Combined Cycle ◽

In 2003 the M501G at Mitsubishi’s in-house combined cycle power plant facility located at Takasago (T-Point) was upgraded. The upgrade was accomplished by replacing some of the existing hardware in the M501G gas turbine, for further improvements in output and heat rate. The verification testing at this power plant has been continuing with MHI’s latest upgraded combustor technology, that has successfully demonstrated NOx levels at 15ppm and 9ppm or lower emission levels in Mitsubishi’s G and F gas turbines, respectively. The upgraded M501G has been officially designated as the M501G1 gas turbine. This paper describes the upgraded hardware and the operating experience at the T-Point power plant.

Volume 3: Coal, Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration Applications; Organic Rankine Cycle Power Systems ◽

Performance Analysis of a Combined Cycle Power Plant Through Exergetic and Environmental Indices

10.1115/gt2017-65027 ◽

2017 ◽

Author(s):

Edgar Vicente Torres González ◽

Raúl Lugo Leyte ◽

Martín Salazar Pereyra ◽

Helen Denise Lugo Méndez ◽

Miguel Toledo Velázquez ◽

...

Keyword(s):

Power Plant ◽

Gas Turbine ◽

Gas Turbines ◽

Combined Cycle ◽

Environmental Indices ◽

Combustion Gases ◽

Combined Cycle Plant ◽

Exergetic Analysis ◽

Gas Turbine Power Plant

In this paper is carried out a comparison between a gas turbine power plant and a combined cycle power plant through exergetic and environmental indices in order to determine performance and sustainability aspects of a gas turbine and combined cycle plant. First of all, an exergetic analysis of the gas turbine and the combined is carried out then the exergetic and environmental indices are calculated for the gas turbine (case A) and the combined cycle (case B). The exergetic indices are exergetic efficiency, waste exergy ratio, exergy destruction factor, recoverable exergy ratio, environmental effect factor and exergetic sustainability. Besides, the environmental indices are global warming, smog formation and acid rain indices. In the case A, the two gas turbines generate 278.4 MW; whereas 415.19 MW of electricity power is generated by the combined cycle (case B). The results show that exergetic sustainability index for cases A and B are 0.02888 and 0.1058 respectively. The steam turbine cycle improves the overall efficiency, as well as, the reviewed exergetic indexes. Besides, the environmental indices of the gas turbines (case A) are lower than the combined cycle environmental indices (case B), since the combustion gases are only generated in the combustion chamber.

Volume 3: Coal, Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration; Organic Rankine Cycle Power Systems ◽

Exergoeconomic Analysis of a Combined Cycle of Three Levels of Pressure

10.1115/gt2016-57872 ◽

2016 ◽

Author(s):

Edgar Vicente Torres González ◽

Raúl Lugo-Leyte ◽

Martín Salazar-Pereyra ◽

Miguel Toledo Velázquez ◽

Helen Denise Lugo-Méndez ◽

...

Keyword(s):

Power Plant ◽

Gas Turbines ◽

Heat Recovery ◽

Systematic Approach ◽

Combined Cycle ◽

Exergetic Efficiency ◽

Steam Generators ◽

Exergoeconomic Analysis ◽

The Cost

This paper presents an exergoeconomic analysis of the combined cycle power plant Tuxpan II located in Mexico. The plant is composed of two identical modules conformed by two gas turbines generating the required work and releasing the hot exhaust gases in two heat recovery steam generators. These components generate steam at three different pressure levels, used to produce additional work in one steam turbine. The productive structure of the considered system is used to visualize the cost formation process as well as the productive interaction between their components. The exergoeconomic analysis is pursued by 1) carrying out a systematic approach, based on the Fuel-Product methodology, in each component of the system; and 2) generating a set of equations, which allows compute the exergetic and exergoeconomic costs of each flow. The thermal and exergetic efficiency of the two gas turbines delivering 278.4 MW are 35.16% and 41.90% respectively. The computed thermal efficiency of the steam cycle providing 80.96 MW is 43.79%. The combined cycle power plant generates 359.36 MW with a thermal and exergetic efficiency of 47.27% and 54.10% respectively.

Introducing the 1S.W501G Single-Shaft Combined-Cycle Reference Power Plant

ASME 2004 Power Conference ◽

10.1115/power2004-52072 ◽

2004 ◽

Cited By ~ 4

Author(s):

Christian Engelbert ◽

Joseph J. Fadok ◽

Robert A. Fuller ◽

Bernd Lueneburg

Keyword(s):

Power Plant ◽

Gas Turbine ◽

Gas Turbines ◽

Power Plants ◽

Combined Cycle ◽

Future Market ◽

Highly Efficient ◽

Fast Start ◽

Plant Efficiency

Driven by the requirements of the US electric power market, the suppliers of power plants are challenged to reconcile both plant efficiency and operating flexibility. It is also anticipated that the future market will require more power plants with increased power density by means of a single gas turbine based combined-cycle plant. Paramount for plant efficiency is a highly efficient gas turbine and a state-of-the-art bottoming cycle, which are well harmonized. Also, operating and dispatch flexibility requires a bottoming cycle that has fast start, shutdown and cycling capabilities to support daily start and stop cycles. In order to meet these requirements the author’s company is responding with the development of the single-shaft 1S.W501G combined-cycle power plant. This nominal 400MW class plant will be equipped with the highly efficient W501G gas turbine, hydrogen-cooled generator, single side exhausting KN steam turbine and a Benson™ once-through heat recovery steam generator (Benson™-OT HRSG). The single-shaft 1S.W501G design will allow the plant not only to be operated economically during periods of high demand, but also to compete in the traditional “one-hour-forward” trading market that is served today only by simple-cycle gas turbines. By designing the plant with fast-start capability, start-up emissions, fuel and water consumption will be dramatically reduced. This Reference Power Plant (RPP) therefore represents a logical step in the evolution of combined-cycle power plant designs. It combines both the experiences of the well-known 50Hz single-shaft 1S.V94.3A plant with the fast start plant features developed for the 2.W501F multi-shaft RPP. The paper will address results of the single-shaft 1S.W501G development program within the authors’ company.

Thermodynamic analysis of heat recovery steam generator in combined cycle power plant

Thermal Science ◽

10.2298/tsci0704143r ◽

2007 ◽

Vol 11 (4) ◽

pp. 143-156 ◽

Cited By ~ 12

Author(s):

Kumar Ravi ◽

Krishna Rama ◽

Rama Sita

Keyword(s):

Power Plant ◽

Steam Turbine ◽

Gas Turbine ◽

Steam Generator ◽

Heat Recovery ◽

Combined Cycle ◽

Heat Recovery Steam Generator ◽

Pressure Steam ◽

Turbine Output

Combined cycle power plants play an important role in the present energy sector. The main challenge in designing a combined cycle power plant is proper utilization of gas turbine exhaust heat in the steam cycle in order to achieve optimum steam turbine output. Most of the combined cycle developers focused on the gas turbine output and neglected the role of the heat recovery steam generator which strongly affects the overall performance of the combined cycle power plant. The present paper is aimed at optimal utilization of the flue gas recovery heat with different heat recovery steam generator configurations of single pressure and dual pressure. The combined cycle efficiency with different heat recovery steam generator configurations have been analyzed parametrically by using first law and second law of thermodynamics. It is observed that in the dual cycle high pressure steam turbine pressure must be high and low pressure steam turbine pressure must be low for better heat recovery from heat recovery steam generator.

Simulation and optimization of a combined cycle power plant with low heating value fuel gas

International Journal of Modeling Simulation and Scientific Computing ◽

10.1142/s1793962321420022 ◽

2021 ◽

pp. 2142002

Author(s):

Renzhi Han ◽

Xin Wang

Keyword(s):

Power Plant ◽

Gas Turbine ◽

Gas Turbines ◽

Combined Cycle ◽

Optimum Operating ◽

Operating Parameters ◽

Outlet Temperature ◽

Mixed Gas ◽

Heat Value

Combined cycle power plant (CCPP) usually plays an important role in balancing byproduct gas generation and consumption in integrated iron and steel plant. The low heat value fuel gases, such as blast furnace gas (BFG) or mixed gas with Coke oven gas (COG) and BFG, are preferred to be used in high-efficient CCPP for power generation. In practice, the general heat value of mixed gas can be set in the range of 3500–4400[Formula: see text]kJ/Nm3. This paper presents a methodology to simulate operating parameters of CCPP with BFG. A generic model of gas turbine with open loop stage cooling employing air is used to simulate the performance of gas turbines cycle under different compressor pressure ratios and turbine inlet temperatures (TIT). The isentropic efficiencies for gas compressor and gas turbine are supposed to be constants and set corresponding to published industrial experience. The steam cycle is composed of classical double-pressure heat recovery steam generator (HRSG) and steam turbines according to gas turbine outlet temperature. Specific work, gas turbine cycle efficiency, cogeneration thermal efficiency and coolant air flow requirements are evaluated to find the optimal compressor pressure ratio and TIT. The research results are useful to select the optimum operating parameters of CCPP with BFG. Performance features were estimated with the help of compression ratios 12.5–20 and combustor exit temperature 1150–1350[Formula: see text]C.

Hot Windbox and Combined Cycle Repowering to Improve Heat Rate

ASME 2010 Power Conference ◽

10.1115/power2010-27274 ◽

2010 ◽

Cited By ~ 2

Author(s):

Tarek A. Tawfik ◽

Thomas P. Smith

Keyword(s):

Steam Turbine ◽

Gas Turbine ◽

Gas Turbines ◽

Heat Recovery ◽

Heat Rate ◽

The United States ◽

Combined Cycle ◽

Plant Performance ◽

Ambient Conditions ◽

North East

Retrofitting existing power generation plants by repowering is becoming an attractive option to improve plant performance with less cost. “Hot Windbox Repowering” involves utilizing the hot exhaust gas from a combustion gas turbine and using it as combustion air for an existing fossil-fuel boiler. “Combined Cycle Repowering” or “Full Repowering” involves completely replacing the existing boiler with a combined cycle consisting of a gas turbine(s) and a heat recovery steam generator (HRSG). The existing steam turbine will be used in both repowering scenarios. This paper discusses an engineering study and summarizes the results obtained from repowering an existing heavy-oil / natural gas fired steam power plant in the north east of the United States. The plant consists of a 600 MW boiler and steam turbine. Several engineering studies were considered and evaluated thermodynamically and economically to retrofit such plant. Several options were considered involving different gas turbines, gas turbine combinations, and different repowering methods. The best option is based on retrofitting the unit by a combination of both, hot windbox repowering and combined cycle repowering. The proposed design consists of one gas turbine repowering the windbox of the existing boiler, and a second gas turbine operating in a separate combined cycle configuration with the generated superheated steam tying into the main steam line and expanding in the existing steam turbine. Several heat balances were developed to assist in obtaining meaningful results for this feasibility study. Actual costs were obtained for the gas turbines and heat recovery steam generators (HRSG), as well as installation costs for a more accurate evaluation. The results indicate that the combined output of the repowered unit will generate an additional 295 MW and reduce the heat rate by more than 11 percent at full load and annual average ambient conditions. The estimated capital cost of the project is expected to range from $235 to $245 millions.

Application of Methodologies to Evaluate the Health State of Gas Turbines in a Cogenerative Combined Cycle Power Plant

Volume 4: Turbo Expo 2002, Parts A and B ◽

10.1115/gt2002-30248 ◽

2002 ◽

Cited By ~ 6

Author(s):

M. Pinelli ◽

M. Venturini

Keyword(s):

Power Plant ◽

Gas Turbine ◽

Gas Turbines ◽

Field Measurements ◽

Combined Cycle ◽

Health State ◽

Measurement Validation ◽

Machine Health ◽

Analysis Of Performance

In the paper, a comprehensive methodology for gas turbine health state determination is applied to a single-shaft Fiat Avio TG 20 gas turbine working in the cogenerative combined cycle power plant of Fiat – Mirafiori (Italy). In order to determine operating state variations from new and clean condition, the following procedures were applied to historical field measurements: • normalization procedure to determine the variations between measured and expected values; • inverse cycle technique to calculate the values of the characteristic parameters that are indices of the machine health state. The application of these techniques to long period operating data allowed measurement validation and the determination of the machine health state. The results showed the good capability of the developed techniques for the determination and the analysis of performance drop due to compressor fouling and to turbine malfunction.