scholarly journals Thermodynamic analysis of heat recovery steam generator in combined cycle power plant

2007 ◽  
Vol 11 (4) ◽  
pp. 143-156 ◽  
Author(s):  
Kumar Ravi ◽  
Krishna Rama ◽  
Rama Sita

Combined cycle power plants play an important role in the present energy sector. The main challenge in designing a combined cycle power plant is proper utilization of gas turbine exhaust heat in the steam cycle in order to achieve optimum steam turbine output. Most of the combined cycle developers focused on the gas turbine output and neglected the role of the heat recovery steam generator which strongly affects the overall performance of the combined cycle power plant. The present paper is aimed at optimal utilization of the flue gas recovery heat with different heat recovery steam generator configurations of single pressure and dual pressure. The combined cycle efficiency with different heat recovery steam generator configurations have been analyzed parametrically by using first law and second law of thermodynamics. It is observed that in the dual cycle high pressure steam turbine pressure must be high and low pressure steam turbine pressure must be low for better heat recovery from heat recovery steam generator.

Author(s):  
A. I. Zwebek ◽  
P. Pilidis

This paper investigates the possibility of applying a new technique called Gas/Steam Path Analysis (GSPA), that is based on the principles of Gas Path Analysis (GPA), to gas as well as steam turbine plants (as one unit) that are main parts of a combined cycle power plant by way of simulation. In order to facilitate this investigation two pieces of software were developed at Cranfield University. With this technique, it was possible to monitor the major components of the combined cycle, and hence predict the faults that may occur within the cycle beforehand. Faults looked at were, fouling and erosion of gas and steam turbine units, heat recovery steam generator degradation (scaling and/or ashe deposition), and condenser degradation. The obtained results from GSPA calculations of the cases investigated showed that “GSPA” technique can be equally applied to either gas turbine cycle, steam turbine cycle, or to the combination of the two in a form of combined cycle. The procedure, assumptions made, and the results obtained are presented and discussed herein.


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.


2020 ◽  
Vol 8 (9) ◽  
pp. 726
Author(s):  
Wahyu Nirbito ◽  
Muhammad Arif Budiyanto ◽  
Robby Muliadi

This study explains the performance analysis of a propulsion system engine of an LNG tanker using a combined cycle whose components are gas turbine, steam turbine, and heat recovery steam generator. The researches are to determine the total resistance of an LNG tanker with a capacity of 125,000 m3 by using the Maxsurf Resistance 20 software, as well as to design the propulsion system to meet the required power from the resistance by using the Cycle-Tempo 5.0 software. The simulation results indicate a maximum power of the system of about 28,122.23 kW with a fuel consumption of about 1.173 kg/s and a system efficiency of about 48.49% in fully loaded conditions. The ship speed can reach up to 20.67 knots.


1979 ◽  
Author(s):  
L. F. Fougere ◽  
H. G. Stewart ◽  
J. Bell

Citizens Utilities Company’s Kauai Electric Division is the electric utility on the Island of Kauai, fourth largest and westernmost as well as northernmost of the Hawaiian Islands. As a result of growing load requirements, additional generating capacity was required that would afford a high level of reliability and operating flexibility and good fuel economy at reasonable capital investment. To meet these requirements, a combined cycle arrangement was completed in 1978 utilizing one existing gas turbine-generator and one new gas turbine-generator, both exhausting to a new heat recovery steam generator which supplies steam to an existing steam turbine-generator. Damper controlled ducting directs exhaust gas from either gas turbine, one at a time, through the heat recovery steam generator. The existing oil-fired steam boiler remains available to power the steam turbine-generator independently or in parallel with the heat recovery steam generator. The gas turbines can operate either in simple cycle as peaking units or in combined cycle, one at a time, as base load units. This arrangement provides excellent operating reliability and flexibility, and the most favorable economics of all generating arrangements for the service required.


Author(s):  
Akber Pasha

The heat recovery steam generator (HRSG) is an integral part of the combined cycle power plant which includes combustion turbine and steam turbine in addition to heat recovery steam generator. The start-up of the heat recovery steam generator, therefore, has an influence on the start-up of the total plant. The paper discusses various constraints, both external and internal, which affect the Steam Generator start-up and in turn influence the start-up of the total plant. Considerations in the design of the steam generator to accommodate the plant start-up requirements, along with the effect of the cyclic or base loaded operation are also discussed. The paper also presents a procedure which may be adopted in the conceptual design of the plant for an optimized system, a system which can accommodate the total plant start-up requirements without undue constraints on the availability of the full plant output.


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