Graph Theoretic Analysis of Advance Combined Cycle Power Plants Alternatives With Latest Gas Turbines

Author(s):  
Nikhil Dev ◽  
Gopal Krishan Goyal ◽  
Rajesh Attri ◽  
Naresh Kumar

In the present work, graph theory and matrix method is used to analyze some of the heat recovery possibilities with the newly available gas turbine engines. The schemes range from dual pressure heat recovery steam generation systems, to triple pressure systems with reheat in supercritical steam conditions. From the developed methodology, result comes out in the form of a number called as index. A real life operating Combined Cycle Power Plant (CCPP) is a very large and complex system. Efficiency of its components and sub-systems are closely intertwined and insuperable without taking the effect of others. For the development of methodology, CCPP is divided into six sub-systems in such a way that no sub-system is independent. Digraph for the interdependencies of sub-system is organized and converted into matrix form for easy computer processing. The results obtained with present methodology are in line with the results available in literature. The methodology is developed with a view that power plant managers can take early decision for selection, improvements and comparison, amongst the various options available, without having in-depth knowledge of thermodynamics analysis.

Author(s):  
Zygfryd Domachowski ◽  
Marek Dzida

Combined cycle power plants operate at thermal efficiency approaching 60 percent. In the same time their performance presents several problems that have to be addressed. E.g. gas turbines are very sensitive to backpressure exerted on them by the heat recovery steam generators as well as to ambient pressure and temperature.


Author(s):  
Rolf H. Kehlhofer

In the past 15 years the combined-cycle (gas/steam turbine) power plant has come into its own in the power generation market. Today, approximately 30 000 MW of power are already installed or being built as combined-cycle units. Combined-cycle plants are therefore a proven technology, showing not only impressive thermal efficiency ratings of up to 50 percent in theory, but also proving them in practice and everyday operation (1) (2). Combined-cycle installations can be used for many purposes. They range from power plants for power generation only, to cogeneration plants for district heating or combined cycles with maximum additional firing (3). The main obstacle to further expansion of the combined cycle principle is its lack of fuel flexibility. To this day, gas turbines are still limited to gaseous or liquid fuels. This paper shows a viable way to add a cheap solid fuel, coal, to the list. The plant system in question is a 2 × 150 MW combined-cycle plant of BBC Brown Boveri with integrated coal gasification plant of British Gas/Lurgi. The main point of interest is that all the individual components of the power plant described in this paper have proven their worth commercially. It is therefore not a pilot plant but a viable commercial proposition.


Author(s):  
S. Can Gülen

Duct firing in the heat recovery steam generator (HRSG) of a gas turbine combined cycle power plant is a commonly used method to increase output on hot summer days when gas turbine airflow and power output lapse significantly. The aim is to generate maximum possible power output when it is most needed (and, thus, more profitable) at the expense of power plant heat rate. In this paper, using fundamental thermodynamic arguments and detailed heat and mass balance simulations, it will be shown that, under certain boundary conditions, duct firing in the HRSG can be a facilitator of efficiency improvement as well. When combined with highly-efficient aeroderivative gas turbines with high cycle pressure ratios and concomitantly low exhaust temperatures, duct firing can be utilized for small but efficient combined cycle power plant designs as well as more efficient hot-day power augmentation. This opens the door to efficient and agile fossil fuel-fired power generation opportunities to support variable renewable generation.


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.


2012 ◽  
Vol 16 (3) ◽  
pp. 901-914 ◽  
Author(s):  
Muammer Alus ◽  
Milan Petrovic

The aim of this work was to develop a new system for optimization of parameters for combined cycle power plants (CCGTs) with triple-pressure heat recovery steam generator (HRSG). Thermodynamic and thermoeconomic optimizations were carried out. The objective of the thermodynamic optimization is to enhance the efficiency of the CCGTs and to maximize the power production in the steam cycle (steam turbine gross power). Improvement of the efficiency of the CCGT plants is achieved through optimization of the operating parameters: temperature difference between the gas and steam (pinch point P.P.) and the steam pressure in the HRSG. The objective of the thermoeconomic optimization is to minimize the production costs per unit of the generated electricity. Defining the optimal P.P. was the first step in the optimization procedure. Then, through the developed optimization process, other optimal operating parameters (steam pressure and condenser pressure) were identified. The developed system was demonstrated for the case of a 282 MW CCGT power plant with a typical design for commercial combined cycle power plants. The optimized combined cycle was compared with the regular CCGT plant.


Author(s):  
Kwangkook Jeong

A section to delineate ‘waste heat recovery’ has been written to contribute for the ASME Power Plant Cooling Specification/Decision-making Guide to be published in 2013. This paper informs tentative contents for the section on how to beneficially apply waste heat and water recovery technology into power plants. This paper describes waste heat recovery in power plant, current/innovative technologies, specifications, case study, combined cycle, thermal benefits, effects on system efficiency, economic and exergetic benefits. It also outlines water recovery technologies, benefits in fresh water consumptions, reducing acids emission, additional cooling effects, economic analysis and critical considerations.


Author(s):  
M. D. Duran ◽  
A. Rovira

It is the purpose of this work to show how to select the best configuration as a function of the combined cycle power. It uses thermo-economic optimization technique based on flexible genetic algorithms (GA). These results will be based on a Thermoeconomic model developed in previous works, this maximizes the cash flow by choosing the correct parameters for the plant design — particularly those corresponding to the HRSG — subject to the restriction that hypothetical, but realistic turbines have already been chosen. This study begins with an analysis of the trends in the commercial gas turbines (GT) design. It was observed that in spite of the diverse companies, the design parameters as well as the turbine cost, follow certain trends depending on the turbine power. When a CCGT power plant is planned, once the GT is selected, is necessary to determine which configuration of the HRSG is the most appropriate in order to get the maximum performance and the best economical results. There is a wide variety of selections of CCGT power plants configurations. To facilitate the analysis of this ample number of CCGT systems we will apply our study to the following types of HRSG: Double pressure with and without reheater, Triple pressure levels with reheater and Triple pressure levels with reheater and supercritical pressure. As a result of this study it may be observed that some design trends should be established so as to decide which configuration (including supercritical cycles) is better to select to specific power.


Author(s):  
Edgar Vicente Torres González ◽  
Raúl Lugo-Leyte ◽  
Martín Salazar-Pereyra ◽  
Miguel Toledo Velázquez ◽  
Helen Denise Lugo-Méndez ◽  
...  

This paper presents an exergoeconomic analysis of the combined cycle power plant Tuxpan II located in Mexico. The plant is composed of two identical modules conformed by two gas turbines generating the required work and releasing the hot exhaust gases in two heat recovery steam generators. These components generate steam at three different pressure levels, used to produce additional work in one steam turbine. The productive structure of the considered system is used to visualize the cost formation process as well as the productive interaction between their components. The exergoeconomic analysis is pursued by 1) carrying out a systematic approach, based on the Fuel-Product methodology, in each component of the system; and 2) generating a set of equations, which allows compute the exergetic and exergoeconomic costs of each flow. The thermal and exergetic efficiency of the two gas turbines delivering 278.4 MW are 35.16% and 41.90% respectively. The computed thermal efficiency of the steam cycle providing 80.96 MW is 43.79%. The combined cycle power plant generates 359.36 MW with a thermal and exergetic efficiency of 47.27% and 54.10% respectively.


2021 ◽  
Vol 2096 (1) ◽  
pp. 012123
Author(s):  
M V Garievskii

Abstract The purpose of the research is to select the priorities for the development of various types of power plants and to substantiate the structure of generating capacities. An improved method has been developed for the selection of priorities for the development of various types of power plants, taking into account the service life and economic performance of the main equipment of power plants in variable modes based on equivalent operating hours. The influence of variable modes of combined-cycle gas installations on the service life of the main equipment (steam and gas turbines) is studied. The comparative efficiency of CCGT-450 in variable modes is calculated, taking into account the wear of the main equipment. As a result of calculations, it was found that with the minimum forecast prices for natural gas, the most efficient power plant (among those considered) is combined cycle power plant, which provides the lowest prime cost of electricity when operating in the base mode and the least increase in the prime cost of electricity when operating in an alternating mode.


Author(s):  
S. Nogami ◽  
N. Ando ◽  
Y. Noguchi ◽  
K. Takahashi ◽  
T. Iwamiya ◽  
...  

Kyushu Electric Power Co., Inc., in constructing the recently completed first phase of the No. 1 Group of Shin-Oita Power Plant, Oita Prefecture (Kyushu Island), achieved further improvements over previous combined cycle plants, especially in the area of plant overall operation. It is composed of six combined cycle power units of the single-shaft, non-reheat type, based on Hitachi-GE MS7001E gas turbines, with a total output of 690 MW. Trial operations of the first unit began in May, 1990. Commercial operations of the first unit began in November 1990, and the last unit in June, 1991. The NO.1 Group incorporates two major advances over previous combined cycle plants. The first advance is a two-stage multiple nozzle dry-type low-NOx combustor. This combustor is a new development for keeping the level of NOx emissions below 62.5 ppm (16% O2 at gas turbine exhaust). The second advance is a new functionally and hierarchically distributed digital control system. By the control system, the plant was designed to bring the following notable features: 1 The individual units can be started and stopped automatically from the load dispatching directive center at the head office. 2 The plant can be operated for high efficiency with short starting and stopping time and large load variations. 3 Plant operating characteristics for emergency operations can be improved remarkably, for instance, load run back operations and fast cut back operation, etc. The results of trial operations have shown that the output per unit is about 0.5 to 4.2% higher, and the unit efficiency about 1.9 to 3.7% higher, than the planned values (all percentages relative), and tangible improvements and starting characteristics and load fluctuation are also satisfactory with the specified target values in the overall operation of the plant over that of previous combined cycle power plants. This plant has satisfactorily been operated since the start of commercial operation.


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