Risk-Based Assessment of Unplanned Outage Events and Costs for Combined-Cycle Plants

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Dale Grace ◽  
Thomas Christiansen
Keyword(s):  
Gas Turbine ◽  
Cash Flow ◽  
Gas Turbines ◽  
Statistical Approach ◽  
Combined Cycle ◽  
Maintenance Costs ◽  
Plant Availability ◽  
The Impact ◽  
Overall Reliability ◽  
Reliability And Availability

Unexpected outages and maintenance costs reduce plant availability and can consume significant resources to restore the unit to service. This paper describes a survey and analysis of unplanned outage events for 388 combined-cycle plants, based on 164 D/E-Class and 224 F-Class gas turbines. The 15-year timeframe included over 3000 unit-years of data. The causes and durations of forced outages and unscheduled maintenance were identified, and overall reliability and availability were established for each class of plant. Costs to restore the unit to service for each main outage cause were estimated, as were net revenues lost due to unplanned outages. A statistical approach to estimated costs and lost revenues provides a risk-based means to quantify the impact of unplanned events on plant cash flow as a function of class of gas turbine and plant subsystem. The risk-based assessment defines the range of probable costs of unplanned outage events.

Risk-Based Assessment of Unplanned Outage Events and Costs for Combined-Cycle-Plants

2012 ◽  
Author(s):  
Dale Grace ◽  
Thomas Christiansen
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Cash Flow ◽  
Gas Turbines ◽  
Operational Reliability ◽  
Combined Cycle ◽  
Maintenance Costs ◽  
Wide Range ◽  
Turbine Equipment ◽  
The Impact

Unexpected outages and maintenance costs reduce plant availability and can consume significant resources to restore the unit to service. Although companies may have the means to estimate cash flow requirements for scheduled maintenance and on-going operations, estimates for unplanned maintenance and its impact on revenue are more difficult to quantify, and a large fleet is needed for accurate assessment of its variability. This paper describes a study that surveyed 388 combined-cycle plants based on 164 D/E-class and 224 F-class gas turbines, for the time period of 1995 to 2009. Strategic Power Systems, Inc. (SPS®), manager of the Operational Reliability Analysis Program (ORAP®), identified the causes and durations of forced outages and unscheduled maintenance and established overall reliability and availability profiles for each class of plant in 3 five-year time periods. This study of over 3,000 unit-years of data from 50 Hz and 60 Hz combined-cycle plants provides insight into the types of events having the largest impact on unplanned outage time and cost, as well as the risks of lost revenue and unplanned maintenance costs which affect plant profitability. Outage events were assigned to one of three subsystems: the gas turbine equipment, heat recovery steam generator (HRSG) equipment, or steam turbine equipment, according to the Electric Power Research Institute’s Equipment Breakdown Structure (EBS). Costs to restore the unit to service for each main outage cause were estimated, as were net revenues lost due to unplanned outages. A statistical approach to estimated costs and lost revenues provides a risk-based means to quantify the impact of unplanned events on plant cash flow as a function of class of gas turbine, plant subsystem, and historical timeframe. This statistical estimate of the costs of unplanned outage events provides the risk-based assessment needed to define the range of probable costs of unplanned events. Results presented in this paper demonstrate that non-fuel operation and maintenance costs are increased by roughly 8% in a typical combined-cycle power plant due to unplanned maintenance events, but that a wide range of costs can occur in any single year.

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.

Limiting the Maintenance Impact of Frequency Regulation Duty on Simple and Combined Cycle Gas Turbine Power Plants

1997 ◽  
Author(s):  
William I. Rowen
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Low Cycle Fatigue ◽  
Combined Cycle ◽  
Frequency Regulation ◽  
Cycle Fatigue ◽  
Thermally Induced ◽  
System Frequency ◽  
The Impact

As more new power plants based on gas turbines enter service, the need for these plants to participate in grid frequency regulation, as opposed to providing blocks of base load power on a dispatchable basis, increases dramatically, exposing this equipment to the potential for accelerated thermal fatigue duty. This paper proposes a methodology for quantifying and limiting the maintenance impact of rapid load changes imposed on gas turbines when required to provide frequency regulation service to the connected utility. The paper includes a discussion of the need for prime movers to participate in system frequency regulation and the impact of this type of service on gas turbine operation. The physics of thermally induced low cycle fatigue is then discussed, and the relationships are quantified using a multiple time constant approach that provides guidance for estimating the transient thermal characteristics of the turbine airfoils that are susceptible to thermally induced low cycle fatigue. This is used to develop the thermo-mechanical relationships that are pertinent to gas turbines in generator drive service. Finally, this material is related back to operational considerations in utilizing gas turbines for system frequency regulation duty.

Integrating the Staged Prevaporizer-Premixer Into Gas Turbine Cycles

2002 ◽  
Author(s):  
J. S. Campbell ◽  
P. C. Malte ◽  
S. de Bruyn Kops ◽  
I. Novosselov ◽  
John C. Y. Lee ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Liquid Fuel ◽  
Water Injection ◽  
Combined Cycle ◽  
Exhaust Gas ◽  
Reduction Of Nox ◽  
Nox Control ◽  
Cycle Efficiency ◽  
The Impact

This paper describes a cycle analysis study on the use of the staged prevaporizer-premixer injector (SPP) in high-pressure gas turbine systems fired with liquid fuel. A review of the SPP is given, including discussions of its operational concepts and previous research. The main portions of the paper consist of analyzing the use of the SPP in three different gas turbine systems: a steam-injected gas turbine (STIG) engine, a Frame H gas turbine in combined cycle, and a reheat gas turbine in combined cycle. Focus is placed on determining the effect of the SPP on cycle efficiency. In addition, SPP use in an engine conventionally recuperated by heat exchange from the exhaust gas stream to the compressor discharge air is examined. The SPP offers the potential of low NOx emissions for liquid-fired gas turbines. Because water injection is a method currently practiced for the reduction of NOx, simulations of engines without the SPP but with water injection into the combustor are also performed and comparisons are made. The simulation process is described, as are methods of how the SPP is implemented into the various engines. Results of the study are given, showing the effect of SPP use on cycle efficiency. In general, except for application to the conventionally recuperated engine, use of the SPP causes a decrease in cycle efficiency of around 1–3 percent (relative). The impact of water injection is somewhat greater, causing a 2.5–4 percent (relative) decrease in cycle efficiency. Further, the water injection does not provide as much NOx control as the lean prevaporized-premixed combustion.

Addressing the Energy Trilemma With LPG-Fuelled, Water-Free Combined Cycle Power Plants

2020 ◽  
Author(s):  
Michael Welch
Keyword(s):  
Environmental Impact ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
High Efficiency ◽  
Gas Production ◽  
Combined Cycle ◽  
Liquefied Petroleum Gas ◽  
Distributed Power ◽  
The Impact

Abstract Many parts of the world are facing the triple challenge of providing secure energy to fuel economic growth at an affordable cost while minimizing the impact of energy production on the environment. Island nations especially struggle to address this trilemma, as renewable resources are usually limited and fossil fuels imported. Traditionally such distributed power plants have relied on liquid fuels and multiple open cycle reciprocating engines to provide both redundancy and the ability to load follow across a broad load range to maximize efficiency. This approach has created high electricity prices and significant negative environmental impact, especially that attributed to CO2, NOx, and SOx. With increasing natural gas production, the availability of Liquefied Petroleum Gas (LPG) has grown, and costs have fallen, allowing the potential to switch from fuel oils to LPG to reduce environmental impacts. Energy costs and environmental impact can be further reduced by using high efficiency Gas Turbine Combined Cycle plants with dry low emissions combustion technology. However, a further hurdle facing many locations is lack of the fresh water required for combined cycle operations. LPG-fuelled Gas Turbine Combined Cycle using Organic Rankine Cycle (ORC) technology can address all aspects of this energy trilemma. This paper reviews the conceptual design of a proposed 100MW distributed power plant for an island location, based on multiple LPG-fuelled gas turbines to follow load demand, with an ORC bottoming cycle to maximize efficiency.

scholarly journals GE MS7001 Gas Turbine Advanced Technology Uprate

1996 ◽  
Author(s):  
Michael A. Cocca ◽  
Arthur Stappenbeck ◽  
James Van Wormer
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Advanced Technology ◽  
Plant Performance ◽  
Maintenance Costs ◽  
Performance Improvements ◽  
Efficiency Increase ◽  
Total Plant ◽  
Plant Efficiency

Today’s competitive world of Independent Power Producers and electric wheeling has increased demand for lower operating and maintenance costs and increased revenues. This need is driving gas turbine research and development. Application of advanced technology to operating units can increase output, improve total plant efficiency, increase steam production and reduce maintenance costs. Cogen Technologies is one owner that has applied advanced technology to uprate five Frame 7EA gas turbines at its Linden plant and one unit at its Camden facility. At the Linden plant, total plant efficiency was improved by more than 2%. This paper will discuss the components included in these advanced technology uprates, the gas turbine and combined-cycle plant performance improvements that were realized, and an economic model that can be used to evaluate the potential benefits of an uprate.

Modern opportunities for preparation of ultra-pure water for feeding high-performance boiler plants

2020 ◽  
pp. 74-84
Author(s):  
A.A. Filimonova ◽  
◽  
N.D. Chichirova ◽  
A.A. Chichirov ◽  
A.A. Batalova ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Performance ◽  
Waste Heat ◽  
Pure Water ◽  
Combined Cycle ◽  
Feed Water ◽  
Operational Characteristics ◽  
Treatment Equipment

The article provides an overview of modern high-performance combined-cycle plants and gas turbine plants with waste heat boilers. The forecast for the introduction of gas turbine equipment at TPPs in the world and in Russia is presented. The classification of gas turbines according to the degree of energy efficiency and operational characteristics is given. Waste heat boilers are characterized in terms of design and associated performance and efficiency. To achieve high operating parameters of gas turbine and boiler equipment, it is necessary to use, among other things, modern water treatment equipment. The article discusses modern effective technologies, the leading place among which is occupied by membrane, and especially baromembrane methods of preparing feed water-waste heat boilers. At the same time, the ion exchange technology remains one of the most demanded at TPPs in the Russian Federation.

scholarly journals Comprehensive Thermodynamic Analysis of the Humphrey Cycle for Gas Turbines with Pressure Gain Combustion

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3521 ◽  
Author(s):  
Panagiotis Stathopoulos
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Process ◽  
Ideal Gas ◽  
Point Of View ◽  
Pressure Gain Combustion ◽  
Combustion Technology ◽  
Secondary Air ◽  
And Performance ◽  
The Impact

Conventional gas turbines are approaching their efficiency limits and performance gains are becoming increasingly difficult to achieve. Pressure Gain Combustion (PGC) has emerged as a very promising technology in this respect, due to the higher thermal efficiency of the respective ideal gas turbine thermodynamic cycles. Up to date, only very simplified models of open cycle gas turbines with pressure gain combustion have been considered. However, the integration of a fundamentally different combustion technology will be inherently connected with additional losses. Entropy generation in the combustion process, combustor inlet pressure loss (a central issue for pressure gain combustors), and the impact of PGC on the secondary air system (especially blade cooling) are all very important parameters that have been neglected. The current work uses the Humphrey cycle in an attempt to address all these issues in order to provide gas turbine component designers with benchmark efficiency values for individual components of gas turbines with PGC. The analysis concludes with some recommendations for the best strategy to integrate turbine expanders with PGC combustors. This is done from a purely thermodynamic point of view, again with the goal to deliver design benchmark values for a more realistic interpretation of the cycle.

scholarly journals Powering Ahead

2011 ◽  
Vol 133 (05) ◽  
pp. 30-33 ◽  
Author(s):  
Lee S. Langston
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Nuclear Power ◽  
Electrical Power ◽  
The United States ◽  
Combined Cycle ◽  
Electrical Power System ◽  
Efficient Technology ◽  
The Military

This article explores the increasing use of natural gas in different turbine industries and in turn creating an efficient electrical system. All indications are that the aviation market will be good for gas turbine production as airlines and the military replace old equipment and expanding economies such as China and India increase their air travel. Gas turbines now account for some 22% of the electricity produced in the United States and 46% of the electricity generated in the United Kingdom. In spite of this market share, electrical power gas turbines have kept a much lower profile than competing technologies, such as coal-fired thermal plants and nuclear power. Gas turbines are also the primary device behind the modern combined power plant, about the most fuel-efficient technology we have. Mitsubishi Heavy Industries is developing a new J series gas turbine for the combined cycle power plant market that could achieve thermal efficiencies of 61%. The researchers believe that if wind turbines and gas turbines team up, they can create a cleaner, more efficient electrical power system.

Combined Cycle Powerplant Cost Sensitivity Analysis

2021 ◽  
Author(s):  
Pugalenthi Nanadagopal ◽  
Animesh Pandey ◽  
Manjunath More ◽  
Pertik Kamboj
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Combined Cycle ◽  
Maintenance Cost ◽  
Combine Cycle Power Plant ◽  
Manufacturing Companies ◽  
Levelized Cost Of Electricity ◽  
Combine Cycle ◽  
Electrical Generation ◽  
The Impact

Abstract In Gas turbine-based combined cycle power plant market, the customer conducts an economic evaluation of competitive products to decide their buying option. There are different methods to calculate the economics of a power plant like Levelized cost of electricity (LCOE), Net present value (NPV) and payback period. LCOE methodology is commonly used for lifecycle cost analyses for combine cycle power plant that covers cost details of the plant and plant performance over the complete lifetime of a power plant from construction to retiring. Typically, it includes a combine cycle power plant ownership costs (Total plant cost and operating & maintenance cost) and combine cycle power output and efficiency. This LCOE method is helpful to compare power generation system that use similar technologies. This paper encompasses the LCOE calculation method, assumptions & approach to analyze the impact of key parameters of the electrical generation cost. They key parameters includes combine cycle output, combine cycle efficiency, fuel cost, annual operating hours, capital charge factor, annual operating hours, power plant life, discount rate, nominal escalation rate, operating & maintenance cost. This paper analyses result will provide insights to the customer & Gas turbine-based OEM (Own Equipment Manufacturing) companies to focus on different area/parameters to reduce the unit cost of generating electricity.

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