The Thermoeconomic and Environomic Modeling and Optimization of the Synthesis, Design, and Operation of Combined Cycles With Advanced Options

2000 ◽  
Vol 123 (4) ◽  
pp. 717-726 ◽  
Author(s):  
S. Pelster ◽  
D. Favrat ◽  
M. R. von Spakovsky

Combined cycle power plants are currently one of the most important options for the construction of new generating capacity as well as for the replacement and repowering of existing units. Due to the complexity and the large number of options and parameters available to such plants, finding optimized solutions for system synthesis, design, and operation is very difficult if not impossible with these traditional methods such as case and parametric tradeoff studies. This is especially true when advanced options as well as thermodynamic, economic, and environmental criteria are considered. A thermoeconomic environomic methodology to deal with these difficulties is presented here. Results for the application of this methodology to a 50 MW cogeneration combined cycle power plant are presented and discussed.

Author(s):  
Hsiao-Wei D. Chiang ◽  
Pai-Yi Wang ◽  
Hsin-Lung Li

With increasing demand for power and with shortages envisioned especially during the peak load times during the summer, there is a need to boost gas turbine power. In Taiwan, most of gas turbines operate with combined cycle for base load. Only a small portion of gas turbines operates with simple cycle for peak load. To prevent the electric shortage due to derating of power plants in hot days, the power augmentation strategies for combined cycles need to be studied in advance. As a solution, our objective is to add an overspray inlet fogging system into an existing gas turbine-based combined cycle power plant (CCPP) to study the effects. Simulation runs were made for adding an overspray inlet fogging system to the CCPP under various ambient conditions. The overspray percentage effects on the CCPP thermodynamic performance are also included in this paper. Results demonstrated that the CCPP net power augmentation depends on the percentage of overspray under site average ambient conditions. This paper also included CCPP performance parametric studies in order to propose overspray inlet fogging guidelines for combined cycle power augmentation.


2011 ◽  
Vol 110-116 ◽  
pp. 4607-4614
Author(s):  
M. Nematollahi ◽  
M. Rezaeian

Flow-induced corrosion is one of the most prevalent tube damage mechanisms in steam generators of power plants. In this study, tube failure of a steam generator in Fars Combined Cycle Power Plant is evaluated. In addition to analysis of the measured tube thicknesses and the failure statistics data, computational fluid dynamic (CFD) methods are used to simulate flow distribution inside and outside of the tubes in one header of the low pressure circuit of the plant steam generator. The results show that regarding the created two-phase flow pattern inside the tubes, the droplet impingement erosion is the main source of tube failures in the bending areas where the extrados surface of the tubes are partially prone to the droplets. The results are useful for modifying the design of the steam generator from different viewpoints such as, optimal design for appropriate configuration of downcomer, header and footer and tube bending. Also, selecting suitable material for the steam generator tubes and implementation of protective coating in risky areas would benefit from the present results.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hashmi SAM ◽  

The main idea of this research paper is to provide an innovative way of capturing carbon dioxide emissions from a coal powered power plant. This research paper discusses the design and modeling of a carbon capturing membrane which is being used in an IGCC power plant to capture carbon dioxide from its exhaust gases. The modeling and design of the membrane is done using CFD software namely Ansys workbench. The design and modeling is done using two simulations, one describes the design and structure and the second one demonstrates the working mechanism of the membrane. This paper also briefly discusses IGCC which is environmentally benign compared to traditional pulverized coal-fired power plants, and economically feasible compared to the Natural Gas Combine Cycle (NGCC). IGCC power plant is more diverse and offers flexibility in fuel utility. This paper also incorporates a PFD of integrated gasification power plant with the carbon capturing membrane unit integrated in it. Index Terms: Integrated gasification combined cycle power plant, Carbon capture and storage, Gas permeating membrane, CFD based design of gas permeating membrane.


2011 ◽  
Vol 17 (4) ◽  
pp. 437-449 ◽  
Author(s):  
Ali Jozi ◽  
Alsadat Pouriyeh

Growing importance of environmental issues at global and regional levels including pollution of water, air etc. as well as the outcomes such as global warming and climate change has led to being considered environmental aspects as effective factors for power generation. Study ahead, aims at examination of risks resulting from activities of Yazd Combined Cycle Power Plant located in Iran. Method applied in the research is analytical hierarchy process. After identification of factors causing risk, the analytical hierarchy structure of the power plant risks were designed and weight of the criteria and sub-criteria were calculated by intensity probability product using Eigenvector Method and EXPERT CHOICE Software as well. Results indicate that in technological, health-safety, biophysical and socio economic sections of the power plant, factors influenced by the power plant activities like fire and explosion, hearing loss, quantity of groundwater, power generation are among the most important factors causing risk in the power plant. The drop in underground water levels is the most important natural consequence influenced on Yazd Combined Cycle Power Plant.


Entropy ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 655
Author(s):  
Louay Elmorsy ◽  
Tatiana Morosuk ◽  
George Tsatsaronis

The transition towards higher shares of electricity generation from renewable energy sources is shown to be significantly slower in developing countries with low-cost fossil fuel resources. Integrating conventional power plants with concentrated solar power may facilitate the transition towards a more sustainable power production. In this paper, a novel natural gas-fired integrated solar combined-cycle power plant was proposed, evaluated, and optimized with exergy-based methods. The proposed system utilizes the advantages of combined-cycle power plants, direct steam generation, and linear Fresnel collectors to provide 475 MW baseload power in Aswan, Egypt. The proposed system is found to reach exergetic efficiencies of 50.7% and 58.1% for day and night operations, respectively. In economic analysis, a weighted average levelized cost of electricity of 40.0 $/MWh based on the number of day and night operation hours is identified. In exergoeconomic analysis, the costs of thermodynamic inefficiencies were identified and compared to the component cost rates. Different measures for component cost reduction and performance enhancement were identified and applied. Using iterative exergoeconomic optimization, the levelized cost of electricity is reduced to a weighted average of 39.2 $/MWh and a specific investment cost of 1088 $/kW. Finally, the proposed system is found to be competitive with existing integrated solar combined-cycle plants, while allowing a significantly higher solar share of 17% of the installed capacity.


Author(s):  
Christian Engelbert ◽  
Joseph J. Fadok ◽  
Robert A. Fuller ◽  
Bernd Lueneburg

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.


Author(s):  
E. Kakaras ◽  
A. Koumanakos ◽  
A. Doukelis ◽  
D. Giannakopoulos ◽  
Ch. Hatzilau ◽  
...  

Scope of the work presented is to examine and evaluate the state of the art in technological concepts towards the capture and sequestration of CO2 from coal-fired power plants. The discussion is based on the evaluation of a novel concept dealing with the carbonation-calcination process of lime for CO2 capture from coal fired power plants compared to integration of CO2 capture in an Integrated Gasification Combined Cycle power plant. In the novel concept, coal is gasified with steam in the presence of lime. Lime absorbs the CO2 released from the coal, producing limestone. The produced gas can be a low-carbon or even zero-carbon (H2) gas, depending on the ratio of lime added to the process. The produced gas can be used in state-of-the-art combined cycles for electricity generation, producing almost no CO2 emissions or other harmful pollutants. The limestone is regenerated in a second reactor, where pure CO2 is produced, which can be either marketed to industry or sequestered in long term disposal areas. The simulation model of a Combined Cycle power plant, integrating the novel carbonation-calcination process, is based on available data from a typical natural gas fired Combined Cycle power plant. The natural gas fired power plant was adopted to firing with the low-C fuel, maintaining the basic operating characteristics. The performance of the novel concept power plant is compared to that of an IGCC with CO2 removal by means of Selexol absorption. Results from thermodynamic simulation, dealing with the most important features for CO2 reduction, are presented. The operating characteristics, as well as the main figures of the plant energy balances are included. A preliminary economic comparison is also provided, taking into account investment and operating costs, in order to estimate the electricity cost related to the two different technological approaches and the economic constrains towards the potentials for applications are examined. The cycle calculations were performed using the thermodynamic cycle calculation software ENBIPRO (ENergie-BIllanz-PROgram). ENBIPRO is a powerful tool for heat and mass balance calculations, solving complex thermodynamic circuits, calculating the efficiency, and allowing exergetic and exergoeconomic analysis of power plants. The software code models all pieces of equipment that usually appear in power plant installations and can accurately calculate all thermodynamic properties (temperature, pressure, enthalpy) at each node of the thermodynamic circuit, power consumption of each component, flue gas composition etc [1]. The code has proven its validity by accurately simulating a large number of power plants and through comparison of the results with other commercial software.


Author(s):  
Elnaz Rahimi ◽  
Fateme Nakhjavani ◽  
Sara Safari ◽  
Hanieh Nematollahi ◽  
Samira Mardaneh ◽  
...  

Background: Work-related accidents are one of the most important factors in the loss of human lives. With technology and industrial progress, the consequences of accidents due to hazards become more severe and may even stop the work of power plants. This study aimed to identify and assess the risk of hazards in a combined cycle power plant. Methods: The descriptive cross-sectional study was conducted to assess the risk of a combined cycle power plant using the FMEA method. Having studied various documentation and records, holding different meetings, and brainstorming, the risk priority number was calculated and corrective suggestions have been presented. Results: Out of a total of 74 identified risks, 34 (45.94%) were at high risk, and 40 (54.05%) were of medium risk. 85% of the risks had the highest severity levels that could cause explosions and fires, injuries, and burns. Conclusion: It can be mentioned that the risks associated with industries such as power plants were high and preventive measures in such places are very important. Identifying hazards and risk assessments with a standard method such as FMEA was a useful way to prevent accidents and human and financial losses.


1980 ◽  
Author(s):  
J. W. Larson

The idea of a combined cycle power plant integrated with a coal gasification process has attracted broad interest in recent years. This interest is based on unique attributes of this concept which include potentially low pollutant emissions, low heat rate and competitive economics as compared to conventional steam plants with stack gas scrubbing. Results from a survey of technical literature containing performance and economic predictions have been compiled for comparison and evaluation of this new technique. These performance and economic results indicate good promise for near-term commercialization of an integrated gasification combined cycle power plant using current gas turbine firing temperatures. Also, these data show that advancements in turbine firing temperature are expected to provide sufficiently favorable economics for the concept to penetrate the market now held by conventional steam power plants.


Author(s):  
S. Can Gulen ◽  
Raub W. Smith

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.


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