Dynamic simulation of a heat recovery steam generator dedicated to a brine concentration plant

2018 ◽  
Vol 135 (3) ◽  
pp. 1763-1773 ◽  
Author(s):  
Omid Mahdavi Keshavar ◽  
Ali Jafarian ◽  
Morteza Sohrabi Shekafti
Author(s):  
Nicolas J. Mertens ◽  
Falah Alobaid ◽  
Bernd Epple ◽  
Hyun-Gee Kim

The daily operation of combined-cycle power plants is increasingly characterized by frequent start-up and shutdown procedures. In addition to the basic requirement of high efficiency at design load, plant operators therefore acknowledge the relevance of enhanced flexibility in operation — in particular, fast start-ups — for plant competitiveness under changing market conditions. The load ramps during start-up procedure are typically limited by thermal stresses in the heat recovery steam generator (HRSG) due to thick-walled components in the high pressure circuit. Whereas conventional HRSG design is largely based on simple steady-state models, detailed modelling and dynamic simulation of the relevant systems are necessary in order to optimize HRSG design with respect to fast start-up capability. This study investigates the capability of a comprehensive process simulation model to accurately predict the dynamic response of a triple-pressure heat recovery steam generator with reheater from warm and hot initial conditions to the start-up procedure of a heavy-duty gas turbine. The commercial combined-cycle power plant (350 MWel) was modelled with the thermal-hydraulic code Apros. Development of the plant model is based on geometry data, system descriptions and heat transfer calculations established in the original HRSG design. The numerical model is validated with two independent sets of measurement data recorded at the real power plant, showing good agreement.


2013 ◽  
Vol 20 (2) ◽  
pp. 413-423 ◽  
Author(s):  
Xiao-ling Cao ◽  
Zheng-ren Pi ◽  
Shao-jian Jiang ◽  
Wei-hong Yang ◽  
B. Wlodzimerz

2019 ◽  
Vol 66 (5) ◽  
pp. 331-339
Author(s):  
M. N. Maidanik ◽  
A. N. Tugov ◽  
N. I. Mishustin ◽  
A. E. Zelinskii

Author(s):  
Ravin G. Naik ◽  
Chirayu M. Shah ◽  
Arvind S. Mohite

To produce the power with higher overall efficiency and reasonable cost is ultimate aim for the power industries in the power deficient scenario. Though combined cycle power plant is most efficient way to produce the power in today’s world, rapidly increasing fuel prices motivates to define a strategy for cost-effective optimization of this system. The heat recovery steam generator is one of the equipment which is custom made for combined cycle power plant. So, here the particular interest is to optimize the combined power cycle performance through optimum design of heat recovery steam generator. The case of combined cycle power plant re-powered from the existing Rankine cycle based power plant is considered to be simulated and optimized. Various possible configuration and arrangements for heat recovery steam generator has been examined to produce the steam for steam turbine. Arrangement of heat exchangers of heat recovery steam generator is optimized for bottoming cycle’s power through what-if analysis. Steady state model has been developed using heat and mass balance equations for various subsystems to simulate the performance of combined power cycles. To evaluate the performance of combined power cycles and its subsystems in the view of second law of thermodynamics, exergy analysis has been performed and exergetic efficiency has been determined. Exergy concepts provide the deep insight into the losses through subsystems and actual performance. If the sole objective of optimization of heat recovery steam generator is to increase the exergetic efficiency or minimizing the exergy losses then it leads to the very high cost of power which is not acceptable. The exergo-economic analysis has been carried to find the cost flow from each subsystem involved to the combined power cycles. Thus the second law of thermodynamics combined with economics represents a very powerful tool for the systematic study and optimization of combined power cycles. Optimization studies have been carried out to evaluate the values of decision parameters of heat recovery steam generator for optimum exergetic efficiency and product cost. Genetic algorithm has been utilized for multi-objective optimization of this complex and nonlinear system. Pareto fronts generated by this study represent the set of best solutions and thus providing a support to the decision-making.


Author(s):  
Akber Pasha

In recent years the combined cycle has become a very attractive power plant arrangement because of its high cycle efficiency, short order-to-on-line time and flexibility in the sizing when compared to conventional steam power plants. However, optimization of the cycle and selection of combined cycle equipment has become more complex because the three major components, Gas Turbine, Heat Recovery Steam Generator and Steam Turbine, are often designed and built by different manufacturers. Heat Recovery Steam Generators are classified into two major categories — 1) Natural Circulation and 2) Forced Circulation. Both circulation designs have certain advantages, disadvantages and limitations. This paper analyzes various factors including; availability, start-up, gas turbine exhaust conditions, reliability, space requirements, etc., which are affected by the type of circulation and which in turn affect the design, price and performance of the Heat Recovery Steam Generator. Modern trends around the world are discussed and conclusions are drawn as to the best type of circulation for a Heat Recovery Steam Generator for combined cycle application.


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