Assessment of Gas Turbine and Combined Cycle Power Plant Performance Degradation

2011 ◽  
Author(s):  
Nina Hepperle ◽  
Dirk Therkorn ◽  
Ernst Schneider ◽  
Stephan Staudacher
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Heat Rate ◽  
Performance Degradation ◽  
Empirical Method ◽  
Combined Cycle ◽  
Performance Data ◽  
Plant Performance ◽  
Water Steam

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.

Application of On-Line Optimization Technology to Plant Operation

2000 ◽  
Author(s):  
Rodney R. Gay
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Heat Rate ◽  
Combined Cycle ◽  
Plant Performance ◽  
Plant Operation ◽  
Budget Analysis ◽  
On Line

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.

An Expanded Cost of Electricity Model for Highly Flexible Power Plants

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
S. Can Gülen ◽  
Indrajit Mazumder
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Combined Cycle ◽  
Plant Performance ◽  
Cost Of Electricity ◽  
Renewable Power ◽  
Effective Performance ◽  
The Impact

Cost of electricity (COE) is the most widely used metric to quantify the cost-performance trade-off involved in comparative analysis of competing electric power generation technologies. Unfortunately, the currently accepted formulation of COE is only applicable to comparisons of power plant options with the same annual electric generation (kilowatt-hours) and the same technology as defined by reliability, availability, and operability. Such a formulation does not introduce a big error into the COE analysis when the objective is simply to compare two or more base-loaded power plants of the same technology (e.g., natural gas fired gas turbine simple or combined cycle, coal fired conventional boiler steam turbine, etc.) and the same (or nearly the same) capacity. However, comparing even the same technology class power plants, especially highly flexible advanced gas turbine combined cycle units with cyclic duties, comprising a high number of daily starts and stops in addition to emissions-compliant low-load operation to accommodate the intermittent and uncertain load regimes of renewable power generation (mainly wind and solar) requires a significant overhaul of the basic COE formula. This paper develops an expanded COE formulation by incorporating crucial power plant operability and maintainability characteristics such as reliability, unrecoverable degradation, and maintenance factors as well as emissions into the mix. The core impact of duty cycle on the plant performance is handled via effective output and efficiency utilizing basic performance correction curves. The impact of plant start and load ramps on the effective performance parameters is included. Differences in reliability and total annual energy generation are handled via energy and capacity replacement terms. The resulting expanded formula, while rigorous in development and content, is still simple enough for most feasibility study type of applications. Sample calculations clearly reveal that inclusion (or omission) of one or more of these factors in the COE evaluation, however, can dramatically swing the answer from one extreme to the other in some cases.

Development of a Combined Cycle Gas Turbine/Steam Plant for Training Marine and Power Engineers

2007 ◽  
Author(s):  
W. Peter Sarnacki ◽  
Richard Kimball ◽  
Barbara Fleck
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Power Industry ◽  
Combined Cycle ◽  
Plant Performance ◽  
Engineering Programs ◽  
Hands On ◽  
Steam Plant

The integration of micro turbine engines into the engineering programs offered at Maine Maritime Academy (MMA) has created a dynamic, hands-on approach to learning the theoretical and operational characteristics of a turbojet engine. Maine Maritime Academy is a fully accredited college of Engineering, Science and International Business located on the coast of Maine and has over 850 undergraduate students. The majority of the students are enrolled in one of five majors offered at the college in the Engineering Department. MMA already utilizes gas turbines and steam plants as part of the core engineering training with fully operational turbines and steam plant laboratories. As background, this paper will overview the unique hands-on nature of the engineering programs offered at the institution with a focus of implementation of a micro gas turbine trainer into all engineering majors taught at the college. The training demonstrates the effectiveness of a working gas turbine to translate theory into practical applications and real world conditions found in the operation of a combustion turbine. This paper presents the efforts of developing a combined cycle power plant for training engineers in the operation and performance of such a plant. Combined cycle power plants are common in the power industry due to their high thermal efficiencies. As gas turbines/electric power plants become implemented into marine applications, it is expected that combined cycle plants will follow. Maine Maritime Academy has a focus on training engineers for the marine and stationary power industry. The trainer described in this paper is intended to prepare engineers in the design and operation of this type of plant, as well as serve as a research platform for operational and technical study in plant performance. This work describes efforts to combine these laboratory resources into an operating combined cycle plant. Specifically, we present efforts to integrate a commercially available, 65 kW gas turbine generator system with our existing steam plant. The paper reviews the design and analysis of the system to produce a 78 kW power plant that approaches 35% thermal efficiency. The functional operation of the plant as a trainer is presented as the plant is designed to operate with the same basic functionality and control as a larger commercial plant.

An Expanded Cost of Electricity Model for Highly Flexible Power Plants

2012 ◽  
Author(s):  
S. Can Gülen ◽  
Indrajit Mazumder
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Combined Cycle ◽  
Plant Performance ◽  
Cost Of Electricity ◽  
Renewable Power ◽  
Effective Performance ◽  
The Impact

Cost of electricity (COE) is the most widely used metric to quantify the cost-performance trade-off involved in comparative analysis of competing electric power generation technologies. Unfortunately, the currently accepted formulation of COE is only applicable to comparisons of power plant options with the same annual electric generation (kilowatt-hours) and same technology as defined by reliability, availability and operability. Such a formulation does not introduce a big error into the COE analysis when the objective is simply to compare two or more baseloaded power plants of the same technology (e.g., natural gas fired gas turbine simple or combined cycle, coal fired conventional boiler steam turbine, etc.) and the same (or nearly the same) capacity. However, comparing even the same technology class power plants, especially highly flexible advanced gas turbine combined cycle units with cyclic duties, comprising a high number of daily starts and stops in addition to emissions-compliant low-load operation to accommodate the intermittent and uncertain load regimes of renewable power generation (mainly wind and solar) requires a significant overhaul of the basic COE formula. This paper develops an expanded COE formulation by incorporating crucial power plant operability and maintainability characteristics such as reliability, unrecoverable degradation, and maintenance factors as well as emissions into the mix. The core impact of duty cycle on the plant performance is handled via effective output and efficiency utilizing basic performance correction curves. The impact of plant start and load ramps on the effective performance parameters is included. Differences in reliability and total annual energy generation are handled via energy and capacity replacement terms. The resulting expanded formula, while rigorous in development and content, is still simple enough for most feasibility study type of applications. Sample calculations clearly reveal that inclusion (or omission) of one or more of these factors in the COE evaluation, however, can dramatically swing the answer from one extreme to the other in some cases.

Gas Turbine Plant Thermal Performance Degradation Assessment

2008 ◽  
Author(s):  
Alexander V. Mirzamoghadam
Keyword(s):  
Gas Turbine ◽  
Performance Monitoring ◽  
Heat Rate ◽  
Performance Degradation ◽  
Combined Cycle ◽  
Plant Performance ◽  
Power Plant Equipment ◽  
Combined Cycle Plant ◽  
Plant Level ◽  
Compressor Power

Knowing the sources behind degradation of gas turbine power and heat rate and the performance of other power plant equipment are critical to equipment manufacturers for guaranteeing their respective performances over the life cycle as well as to utility/plant owners for cost reasons. Many power companies are trying to improve equipment reliability by focusing on Performance Monitoring and the application of advanced diagnostic technologies. The first part of the paper describes a method to monitor gas turbine compressor efficiency, forecast an efficiency decay rate in terms of operating hours, introduce the logic leading to an optimum schedule pertaining on-line/off-line water washing, correct measured real-time gas turbine power and heat rate with respect to the new and clean reference point, and then deduce the respective turbine and compressor power contributions to gas turbine net power degradation. An example is used to aid the planning of a rigorous but effective schedule in compressor washing. The second part focuses on assessing degradation at the plant level (simple or combined cycle). The derived gas turbine degradation methodology is integrated with the overall plant performance degradation, and as a result, the maintenance effectiveness of the most recent outage can be measured. The proposed methodology is applied to a hypothetical combined cycle plant, allowing the identification of possible sources of plant deterioration with recommendations for corrective actions to improve overall power and heat rate.

An Economic Assessment Method of Gas Turbine Power Cycles by Means of Genetic Algorithms

2004 ◽  
Author(s):  
Alcides Codeceira Neto ◽  
Pericles Pilidis ◽  
Anestis I. Kalfas
Keyword(s):  
Genetic Algorithms ◽  
Power Plant ◽  
Performance Assessment ◽  
Gas Turbine ◽  
Power Plants ◽  
Thermal Power ◽  
Assessment Method ◽  
Combined Cycle ◽  
Plant Performance ◽  
Exergy Method

The Performance assessment of power plants involves a large number of equations with many variables taking part in the whole calculation. The assessment method described here takes into account a process for optimising a conventional gas turbine combined cycle power plant from the point of view of power plant performance calculations and economic analysis. The process requires optimisation of the whole thermal power plant based on cost considerations. The performance assessment of power plants uses the exergy method and considers the overall plant exergetic efficiency and the exergy destruction in the various components of the plant. The exergy method highlights irreversibility within plant components, and it is of particular interest in this investigation. Generally, the optimisation procedure to determine an optimal solution for a problem considers constraints imposed to some variables and requires the use of an optimisation technique. This paper is precisely concerned with the use of Genetic Algorithms (GAs) as a recommended tool for applying the optimisation process of the whole power plant based on minimising costs of products. Genetic Algorithms (GAs) are adaptive methods which may be used to solve search and optimisation problems. They are based on the genetic processes of biological organisms and do not require complicated mathematical calculations like the evaluation of derivatives necessary to be considered in conventional optimisation techniques.

Development of Performance Deterioration Diagnosis Method for Gas Turbine Combined Cycle Power Plants

2010 ◽  
Author(s):  
Toru Takahashi ◽  
Eiichi Koda ◽  
Yoshinobu Nakao
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Thermal Power ◽  
Combined Cycle ◽  
Plant Performance ◽  
Maintenance Cost ◽  
Thermal Power Plants ◽  
Performance Deterioration

Recently, it is more necessary to maintain or improve the thermal efficiency of actual thermal power plants to reduce CO2 emission and energy consumption in the world, and it is also important to reduce the maintenance cost of commercial thermal power plants. Thus, it is crucial to investigate power plant performance deterioration factors and solve problems related to these factors promptly when the thermal efficiency decreases. However, it is difficult to understand the internal state of power plants sufficiently and to determine power plant performance deterioration factors only from operation data because actual thermal plants are composed of many components and are very complex systems. In particular, it is more difficult to understand performance deterioration in gas turbine combined cycle (GTCC) power plants than in steam power plants because the performance changes markedly in GTCC power plants depending on atmospheric conditions (temperature, pressure, humidity). In other words, when thermal efficiency changes, it is difficult to determine whether the cause is the change in external factors or that in the performance of the component. Therefore, we develop a method based on heat balance analysis to calculate the immeasurable quantity of state and the efficiency of each component in GTCC power plants, and to correct the performance of each component in a plant to a standard state using the performance function obtained from long-term operation data. Through the method, the analysis of the effects of deterioration factors on thermal efficiency becomes possible, and the performance of a plant can be simulated when the operation conditions are changed. Thus, we can determine the main factor that affects thermal efficiency using our method.

Thermo-Economic Assessment Under Electrical Market Uncertainties of a Combined Cycle Gas Turbine Integrated With a Flue Gas-Condensing Heat Pump

2020 ◽  
Author(s):  
Alberto Vannoni ◽  
Andrea Giugno ◽  
Alessandro Sorce
Keyword(s):  
Power Plant ◽  
Power Systems ◽  
Gas Turbine ◽  
Heat Pump ◽  
Flue Gas ◽  
Power Plants ◽  
Greenhouse Gas Emission ◽  
Capital Expenditure ◽  
Combined Cycle ◽  
Gas Turbine Power Plant

Abstract Renewable energy penetration is growing, due to the target of greenhouse-gas-emission reduction, even though fossil fuel-based technologies are still necessary in the current energy market scenario to provide reliable back-up power to stabilize the grid. Nevertheless, currently, an investment in such a kind of power plant might not be profitable enough, since some energy policies have led to a general decrease of both the average price of electricity and its variability; moreover, in several countries negative prices are reached on some sunny or windy days. Within this context, Combined Heat and Power systems appear not just as a fuel-efficient way to fulfill local thermal demand, but also as a sustainable way to maintain installed capacity able to support electricity grid reliability. Innovative solutions to increase both the efficiency and flexibility of those power plants, as well as careful evaluations of the economic context, are essential to ensure the sustainability of the economic investment in a fast-paced changing energy field. This study aims to evaluate the economic viability and environmental impact of an integrated solution of a cogenerative combined cycle gas turbine power plant with a flue gas condensing heat pump. Considering capital expenditure, heat demand, electricity price and its fluctuations during the whole system life, the sustainability of the investment is evaluated taking into account the uncertainties of economic scenarios and benchmarked against the integration of a cogenerative combined cycle gas turbine power plant with a Heat-Only Boiler.

Short-Term Optimization of a Combined Cycle Power Plant Integrated With an Inlet Air Conditioning Unit

2020 ◽  
Author(s):  
Weimar Mantilla ◽  
José García ◽  
Rafael Guédez ◽  
Alessandro Sorce
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Air Conditioning ◽  
Combined Cycle ◽  
Plant Performance ◽  
Mixed Integer ◽  
Environmental Load ◽  
Turbine Inlet ◽  
The Impact

Abstract Under new scenarios with high shares of variable renewable electricity, combined cycle gas turbines (CCGT) are required to improve their flexibility, in terms of ramping capabilities and part-load efficiency, to help balance the power system. Simultaneously, liberalization of electricity markets and the complexity of its hourly price dynamics are affecting the CCGT profitability, leading the need for optimizing its operation. Among the different possibilities to enhance the power plant performance, an inlet air conditioning unit (ICU) offers the benefit of power augmentation and “minimum environmental load” (MEL) reduction by controlling the gas turbine inlet temperature using cold thermal energy storage and a heat pump. Consequently, an evaluation of a CCGT integrated with this inlet conditioning unit including a day-ahead optimized operation strategy was developed in this study. To establish the hourly dispatch of the power plant and the operation mode of the inlet conditioning unit to either cool down or heat up the gas turbine inlet air, a mixed-integer linear optimization (MILP) was formulated using MATLAB, aiming to maximize the operational profit of the plant within a 24-hours horizon. To assess the impact of the proposed unit operating under this dispatch strategy, historical data of electricity and natural gas prices, as well as meteorological data and CO2 emission allowances price, have been used to perform annual simulations of a reference power plant located in Turin, Italy. Furthermore, different equipment capacities and parameters have been investigated to identify trends of the power plant performance. Lastly, a sensitivity analysis on market conditions to test the control strategy response was also considered. Results indicate that the inlet conditioning unit, together with the dispatch optimization, increases the power plant’s operational profit by achieving a wider operational range, particularly important during peak and off-peak periods. For the specific case study, it is estimated that the net present value of the CCGT integrated with the ICU is 0.5% higher than the power plant without the unit. In terms of technical performance, results show that the unit reduces the minimum environmental load by approximately 1.34% and can increase the net power output by 0.17% annually.

The Elephant in the Room–Gas Turbine Power

2010 ◽  
Vol 132 (12) ◽  
pp. 57-57
Author(s):  
Lee S. Langston
Keyword(s):  
Power Plant ◽  
Electric Power ◽  
Gas Turbine ◽  
Power Plants ◽  
Electrical Power ◽  
Electric Power Industry ◽  
Hydrocarbon Fuel ◽  
Combined Cycle ◽  
Electrical Generator ◽  
Gas Turbine Exhaust

This article presents an overview of gas turbine combined cycle (CCGT) power plants. Modern CCGT power plants are producing electric power as high as half a gigawatt with thermal efficiencies approaching the 60% mark. In a CCGT power plant, the gas turbine is the key player, driving an electrical generator. Heat from the hot gas turbine exhaust is recovered in a heat recovery steam generator, to generate steam, which drives a steam turbine to generate more electrical power. Thus, it is a combined power plant burning one unit of fuel to supply two sources of electrical power. Most of these CCGT plants burn natural gas, which has the lowest carbon content of any other hydrocarbon fuel. Their near 60% thermal efficiencies lower fuel costs by almost half compared to other gas-fired power plants. Their installed capital cost is the lowest in the electric power industry. Moreover, environmental permits, necessary for new plant construction, are much easier to obtain for CCGT power plants.

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