Thermodynamic Modeling and Performance Simulation of Combined Cycle Power Plant Under Design and Off-Design Condition

2021 ◽  
Author(s):  
Lalatendu Pattanayak ◽  
Biranchi Narayana Padhi ◽  
Hemant Gajjar

Abstract Combined cycle power plants (CCPP) are increasingly important for safer and cleaner electricity generation. In this context it is imperative to explore options to enhance its thermal performance for its design and off-design condition. This study presents the performance comparison of two heavy-duty gas turbined (GT) based CCPP with triple pressure steam bottoming cycle. The CCPP system component is modeled using a commercial software Ebsilon and the off-design performance prediction is made using necessary component correlations. The correlations make use of normalized curves that are generated from model runs and apply the factors received from such curve to design performance to estimate the off-design performance. The model simulation is validated against literatures. Furthermore, inlet air cooling technique (IAC) is introduced in this study to enhance the CCPP power production without compromising component performance. The performance comparison of both the CCPP units are presented in an integrated manner by considering interaction of bottoming cycle on GT operation. The results are established as a function of ambient temperature based on energy and exergy principle and the power boosting and economic profit. The results also demonstrate the benefit of IAC on part-load performance. The component level exergy analysis proved that IAC improves the system exergy efficiency.

1999 ◽  
Author(s):  
Luis Correas ◽  
Ángel Martínez ◽  
Antonio Valero

Abstract Diagnosis of the performance of energy was theoretically developed based on the Structural Theory (Valero, Serra and Lozano, 1993), and traditionally Thermoeconomics have usually been applied to the design of power plants and comparison between alternatives. However, the application of thermoeconomic techniques to actual power plants has always to face the generally poor quality of measurement readings from the standard field instrumentation as an unavoidable first step. The proposed methodology focuses on measurement uncertainty estimation and performance calculation by means of data reconciliation techniques, in order to obtain the most confident plant balance upon the available instrumentation. The formulation of the Structural Theory has been applied to a combined cycle, where the Fuel-Product relationships at the component level must be optimally defined for a correct malfunction interpretation. This set of relationships determines the ability to diagnose and the level of the diagnostics obtained. The paper reports the application of the methodology to a 280 MW rated combined cycle, where performance diagnosis is illustrated with results from a collection of actual operation data sets. The results show that data reconciliation yields sufficient accuracy to conduct a thermoeconomic analysis, and how the estimated impact on fuel correlates with physical causes. Hence the feasibility of thermoeconomic analysis of plant operation is demonstrated.


Author(s):  
Sandro B. Ferreira ◽  
Marco Antoˆnio R. do Nascimento

The use of syngas from gasified biomass as fuel for electric power generation based on gas turbine engines has been seriously studied over the past last two decades. Few experimental power plants have been built around the world. A small review of the use of syngas from gasified biomass and a cleaning system for gas turbine engines are presented. In this paper a computational program was presented and validated to simulate the design and off-design performance analysis of simple cycle gas turbine engines with one and two shafts. The aim was to assess the behavior and performance of the gas turbine engine without accounting for auxiliary syngas fuel compressor when the gasifier is atmospheric. It shows the behavior and performance at the off design condition of these two types of hypothetic gas turbine engines. The two engines were designed to use kerosene as fuel and at off-design conditions, and they were run using syngas from gasified biomass. The results show that the running line in the compressor characteristic moves towards the surge line and that the performance changes when the engine runs with the syngas.


2015 ◽  
Vol 76 ◽  
pp. 449-461 ◽  
Author(s):  
Mehdi A. Ehyaei ◽  
Mojtaba Tahani ◽  
Pouria Ahmadi ◽  
Mohammad Esfandiari

Author(s):  
Nicola Palestra ◽  
Giovanna Barigozzi ◽  
Antonio Perdichizzi

The paper presents the results of an investigation on inlet air cooling systems based on cool thermal storage, applied to combined cycle power plants. Such systems provide a significant increase of electric energy production in the peak hours; the charge of the cool thermal storage is performed instead during the night time. The inlet air cooling system also allows the plant to reduce power output dependence on ambient conditions. A 127MW combined cycle power plant operating in the Italian scenario is the object of this investigation. Two different technologies for cool thermal storage have been considered: ice harvester and stratified chilled water. To evaluate the performance of the combined cycle under different operating conditions, inlet cooling systems have been simulated with an in-house developed computational code. An economical analysis has been then performed. Different plant location sites have been considered, with the purpose to weigh up the influence of climatic conditions. Finally, a parametric analysis has been carried out in order to investigate how a variation of the thermal storage size affects the combined cycle performances and the investment profitability. It was found that both cool thermal storage technologies considered perform similarly in terms of gross extra production of energy. Despite this, the ice harvester shows higher parasitic load due to chillers consumptions. Warmer climates of the plant site resulted in a greater increase in the amount of operational hours than power output augmentation; investment profitability is different as well. Results of parametric analysis showed how important the size of inlet cooling storage may be for economical results.


Energy ◽  
2019 ◽  
Vol 178 ◽  
pp. 386-399 ◽  
Author(s):  
Yongping Yang ◽  
Ziwei Bai ◽  
Guoqiang Zhang ◽  
Yongyi Li ◽  
Ziyu Wang ◽  
...  

Author(s):  
John T. Langaker ◽  
Christopher Hamker ◽  
Ralph Wyndrum

Large natural gas fired combined cycle electric power plants, while being an increasingly efficient and cost effective technology, are traditionally large consumers of water resources, while also discharging cooling tower blowdown at a similar rate. Water use is mostly attributed to the heat rejection needs of the gas turbine generator, the steam turbine generator, and the steam cycle condenser. Cooling with air, i.e. dry cooling, instead of water can virtually eliminate the environmental impact associated with water usage. Commissioned in the fall of 2010 with this in mind, the Halton Hills Generating Station located in the Greater Toronto West Area, Ontario, Canada, is a nominally-rated 700 Megawatt combined cycle electric generating station that is 100 percent cooled using various air-cooled heat exchangers. The resulting water consumption and wastewater discharge of this power plant is significantly less than comparably sized electric generating plants that derive cooling from wet methods (i.e, evaporative cooling towers). To incorporate dry cooling into such a power plant, it is necessary to consider several factors that play important roles both during plant design as well as construction and commissioning of the plant equipment, including the dry cooling systems. From the beginning a power plant general arrangement and space must account for dry cooling’s increase plot area requirements; constraints therein may render air cooling an impossible solution. Second, air cooling dictates specific parameters of major and auxiliary equipment operation that must be understood and coordinated upon purchase of such equipment. Until recently traditional wet cooling has driven standard designs, which now, in light of dry cooling’s increase in use, must be re-evaluated in full prior to purchase. Lastly, the construction and commissioning of air-cooling plant equipment is a significant effort which demands good planning and execution.


Author(s):  
Hiroyuki Yamazaki ◽  
Yoshiaki Nishimura ◽  
Masahiro Abe ◽  
Kazumasa Takata ◽  
Satoshi Hada ◽  
...  

Tohoku Electric Power Company, Inc. (Tohoku-EPCO) has been adopting cutting-edge gas turbines for gas turbine combined cycle (GTCC) power plants to contribute for reduction of energy consumption, and making a continuous effort to study the next generation gas turbines to further improve GTCC power plants efficiency and flexibility. Tohoku-EPCO and Mitsubishi Hitachi Power Systems, Ltd (MHPS) developed “forced air cooling system” as a brand-new combustor cooling system for the next generation GTCC system in a collaborative project. The forced air cooling system can be applied to gas turbines with a turbine inlet temperature (TIT) of 1600deg.C or more by controlling the cooling air temperature and the amount of cooling air. Recently, the forced air cooling system verification test has been completed successfully at a demonstration power plant located within MHPS Takasago Works (T-point). Since the forced air cooling system has been verified, the 1650deg.C class next generation GTCC power plant with the forced air cooling system is now being developed. Final confirmation test of 1650deg.C class next generation GTCC system will be carried out in 2020.


2004 ◽  
Vol 126 (4) ◽  
pp. 770-785 ◽  
Author(s):  
Paolo Chiesa ◽  
Ennio Macchi

All major manufacturers of large size gas turbines are developing new techniques aimed at achieving net electric efficiency higher than 60% in combined cycle applications. An essential factor for this goal is the effective cooling of the hottest rows of the gas turbine. The present work investigates three different approaches to this problem: (i) the most conventional open-loop air cooling; (ii) the closed-loop steam cooling for vanes and rotor blades; (iii) the use of two independent closed-loop circuits: steam for stator vanes and air for rotor blades. Reference is made uniquely to large size, single shaft units and performance is estimated through an updated release of the thermodynamic code GS, developed at the Energy Department of Politecnico di Milano. A detailed presentation of the calculation method is given in the paper. Although many aspects (such as reliability, capital cost, environmental issues) which can affect gas turbine design were neglected, thermodynamic analysis showed that efficiency higher than 61% can be achieved in the frame of current, available technology.


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