The Air Injection Power Augmentation Technology Provides Additional Significant Operational Benefits

Author(s):  
Eiji Akita ◽  
Shin Gomi ◽  
Scott Cloyd ◽  
Michael Nakhamkin ◽  
Madhukar Chiruvolu

The Air Injection (AI) Power Augmentation technology (HAI for humid Air injection and DAI for dry air injection) has primary benefits of increasing power of combustion turbine/combined cycle (CT/CC) power plants by 15–30% at a fraction of the new plant cost with coincidental significant heat rate reductions (10–15%) and NOx emissions reductions (for diffusion type combustors up to 60%) (See References 1, 2, 3): Figure 1A is a simplified heat and mass balance for the PG7241 (FA) combustion turbine with HAI. The auxiliary compressor supplies the additional airflow that is mixed with the steam produced by the HRSG and injected upstream of combustors. Figure 1B presents the heat and mass balance for the PG7142 CT based combined cycle power plant with HAI. It is similar to that presented on Figure 1A except that the humid air is created by mixing of steam, extracted from the steam turbine, with the supplementary airflow from the auxiliary compressor. The maximum acceptable injection rates are evaluated with proper margins by a number of factors established by OEMs: the compressor surge limitations, maximum torque, the generator capacities, maximum moisture levels upstream of combustors, etc.

Author(s):  
Michael Nakhamkin ◽  
Robert Pelini ◽  
Manu I. Patel

This paper presents the latest information on Humid Air Injection (HAI) power augmentation technology for Combustion Turbine and Combined Cycle power plants. It describes: a) The summary of the latest activities on the implementation of HAI and Dry Air Injection (DAI) technologies including results of the validations tests conducted on the PG7241 (FA) combustion turbine, and findings of various CT-HAI implementation projects; b) The technical background including the latest CT-HAI and CT-DAI concepts resulting on the performance improvements and reduced emissions; and c) The novel concept for humidification of the injected air that further reduces overall capital costs by 15%.


Author(s):  
Arthur Cohn ◽  
Mark Waters

It is important that the requirements and cycle penalties related to the cooling of high temperature turbines be thoroughly understood and accurately factored into cycle analyses and power plant systems studies. Various methods used for the cooling of high temperature gas turbines are considered and cooling effectiveness curves established for each. These methods include convection, film and transpiration cooling using compressor bleed and/or discharge air. In addition, the effects of chilling the compressor discharge cooling gas are considered. Performance is developed to demonstrate the impact of the turbine cooling schemes on the heat rate and specific power of Combined–Cycle power plants.


Author(s):  
V. C. Tandon ◽  
D. A. Moss

Florida Power and Light Company’s Putnam Station, one of the most efficient power plants in the FP&L system, is in a unique and enviable position from an operational viewpoint. Its operation, in the last seven years, has evolved through a triple phase fuel utilization from distillate to residual oil and finally to natural gas. This paper compares the availability/reliability of the Putnam combined cycle station and the starting reliability of the combustion turbines in each of the operating periods. A review of the data shows that high availability/reliability is not fuel selective when appropriate actions are developed and implemented to counteract the detractors. This paper also includes experience with heat rate and power degradation of various power plant components and programs implemented to restore performance.


Author(s):  
Richard H. Eaton ◽  
Edward R. Blessman ◽  
Kevin G. Schoonover

Premature condenser tube failures in combined cycle power plants have been experienced at several installations related to fatigue and erosion of the condenser tubes. The admission of high energy steam into the condenser poses design challenges with respect to the compact design of the condenser in the combined cycle power plant. Dissipation of energy within the condenser is a specialty design usually performed by the condenser manufacturer. Part 1 of this paper reviews condenser design and plant operation that impacts, or may contribute to, condenser tube failures. Part 2 of this paper reviews the condenser bypass system, identifies related opportunities, and provides design considerations to optimize condenser reliability through the controlled admission of high energy steam into the condenser. A number of factors go into properly designing sub-systems, as required by the functional operation of the combined cycle plant. The bypass system is one sub-system, considered integral with the condenser.


Author(s):  
Julianne M. Klara ◽  
Robert M. Enick ◽  
Scott M. Klara ◽  
Lawrence E. Van Bibber

The purpose of this study is to assess the feasibility of incorporating a Humid Air Turbine (HAT) into a coal-based, indirectly fired High Performance Power System (HIPPS). The HIPPS/HAT power plant exhibits a one percentage point greater thermal efficiency than the combined-cycle HIPPS plant. The capital costs for the HIPPS and HIPPS/HAT plants with identical net power output are nearly equivalent at $1380/kW. Levelized cost of electricity (COE) for the same size plants is 5.3 cents/kWh for the HIPPS plant and 5.4 cents/kWh for the HIPPS/HAT plant; the HIPPS/HAT plant improved thermal efficiency is offset by the higher fuel cost associated with a lower coal/natural gas fuel ratio. However, improved environmental performance is associated with the HIPPS/HAT cycle, as evidenced by lower CO2, SO2, and NOx emissions. Considering the uncertainties associated with the performance and cost estimates of the yet unbuilt components, the HIPPS/HAT and HIPPS power plants are presently considered to be comparable alternatives for future power generation technologies. The Department of Energy’s Combustion 2000 Program will provide revised design specifications and more accurate costs for these components allowing more definitive assessments to be performed.


Author(s):  
Hany Rizkalla ◽  
Timothy Hui ◽  
Fred Hernandez ◽  
Matthew Yaquinto ◽  
Ramesh KeshavaBhattu

Abstract Renewables proliferation in the energy market is driving the need for flexibility in gas fired power plants to enable a wider and emissions compliant operability range. The ability for a gas fired plant to peak fire while maintaining emissions compliance, full life interval capability, improved simple and combined cycle heat rate and the ability to achieve extended turndown, positions a gas fired asset to benefit from an improved capacity factor, and overall economic viability in an increasingly renewables’ dependent energy market. The low pressure drop FlameSheet™ combustor variant’s implementation alongside PSM’s Gas Turbine Optimization Package (GTOP3.1) on a commercially operating frame 7FA heavy duty gas turbine in 2018 and as introduced in GT2019-91647, is presented with emphasis on extended validation of operational and emissions/tuning performance at different ambient conditions, higher peak firing and minimum load after one year of continuous commercial operation. The output and heat rate improvement achieved with the FlameSheet™/GTOP3.1 conversion thus enabling improved capacity is also discussed. As shale gas continue to grow as a dominant source of the U.S Natural gas supply, the need for fuel flexible combustion systems enabling tolerance to higher ethane/ethylene concentrations associated with Shale gas is required for improved operability. The adverse impact and means to mitigate such higher ethane/ethylene content on standard F-Class heavy duty combustion systems is also presented as part of said FlameSheet™/GTOP 3.1 conversion.


Author(s):  
Michael Nakhamkin ◽  
Robert Pelini ◽  
Manu I. Patel ◽  
Ron Wolk

This paper presents the latest information on Humid/Dry Air Injection (HAI/DAI) power augmentation technology for Combustion Turbine (CT) and Combined Cycle (CC) power plants. It describes: • The summary of the latest activities on the implementation of HAI and DAI technologies including results of the validations tests conducted on the PG7241 (FA) combustion turbine, and findings of various CT-HAI implementation projects. • The technical background including the latest CT-HAI and CT-DAI concepts resulting in the performance improvements and reduced emissions. • A novel concept for humidification of the injected air that further reduces overall capital costs by 15%. • The novel approach for the power augmentation of two-shaft small and medium capacity CTs with application of HAI and DAI technologies. Two-shaft CTs are widely used for electric power generation, including distributed generation, as well as a variable-speed mechanical driving engine including driving natural gas (NG) pipeline compressors (PC).


Author(s):  
Nina Hepperle ◽  
Dirk Therkorn ◽  
Ernst Schneider ◽  
Stephan Staudacher

Recoverable and non-recoverable performance degradation has a significant impact on power plant revenues. A more in depth understanding and quantification of recoverable degradation enables operators to optimize plant operation. OEM degradation curves represent usually non-recoverable degradation, but actual power output and heat rate is affected by both, recoverable and non-recoverable degradation. This paper presents an empirical method to correct longterm performance data of gas turbine and combined cycle power plants for recoverable degradation. Performance degradation can be assessed with standard plant instrumentation data, which has to be systematically stored, reduced, corrected and analyzed. Recoverable degradation includes mainly compressor and air inlet filter fouling, but also instrumentation degradation such as condensate in pressure sensing lines, condenser or bypass valve leakages. The presented correction method includes corrections of these effects for gas turbine and water steam cycle components. Applying the corrections on longterm operating data enables staff to assess the non-recoverable performance degradation any time. It can also be used to predict recovery potential of maintenance activities like compressor washings, instrumentation calibration or leakage repair. The presented correction methods are validated with long-term performance data of several power plants. It is shown that the degradation rate is site-specific and influenced by boundary conditions, which have to be considered for degradation assessments.


Author(s):  
Bjorn Kaupang ◽  
Douglas M. Todd

Significant progress has been made in the installation and initial operation of several IGCC power plants. At least six IGCC projects are scheduled to enter commercial operation in the USA and in Europe during 1996. Several additional IGCC projects are under construction or under development using many different gasification systems. Gas turbine manufacturers introduced advanced gas turbine technology in 1995, resulting in IGCC efficiency for coal and heavy oil-fired plants of up to 50% (LHV) with plant costs consistent with conventional steam plants. Gas turbine developments specifically aimed at IGCC applications allow the use of environmentally low quality fuels without added impact on the environment. This paper discusses the current operating experience of several of the initial IGCC plants and illustrates the very attractive fuels flexibility with the combined-cycle plants burning naphtha or distillate oils initially with later conversions to IGCC burning lignite, heavy oil or orimulsion. This paper also discusses the heat rate and output performance capabilities of the IGCC with H level gas turbine technology and the resulting impacts on the cost of electricity from IGCC plants.


Author(s):  
Rodney R. Gay

Traditionally optimization has been thought of as a technology to set power plant controllable parameters (i.e. gas turbine power levels, duct burner fuel flows, auxiliary boiler fuel flows or bypass/letdown flows) so as to maximize plant operations. However, there are additional applications of optimizer technology that may be even more beneficial than simply finding the best control settings for current operation. Most smaller, simpler power plants (such as a single gas turbine in combined cycle operation) perceive little need for on-line optimization, but in fact could benefit significantly from the application of optimizer technology. An optimizer must contain a mathematical model of the power plant performance and of the economic revenue and cost streams associated with the plant. This model can be exercised in the “what-if” mode to supply valuable on-line information to the plant operators. The following quantities can be calculated: Target Heat Rate Correction of Current Plant Operation to Guarantee Conditions Current Power Generation Capacity (Availability) Average Cost of a Megawatt Produced Cost of Last Megawatt Cost of Process Steam Produced Cost of Last Pound of Process Steam Heat Rate Increment Due to Load Change Prediction of Future Power Generation Capability (24 Hour Prediction) Prediction of Future Fuel Consumption (24 Hour Prediction) Impact of Equipment Operational Constraints Impact of Maintenance Actions Plant Budget Analysis Comparison of Various Operational Strategies Over Time Evaluation of Plant Upgrades The paper describes examples of optimizer applications other than the on-line computation of control setting that have provided benefit to plant operators. Actual plant data will be used to illustrate the examples.


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