scholarly journals EXPERIMENTAL AND THEORETICAL INVESTIGATIONS OF NEW POWER CYCLES AND ADVANCED FALLING FILM HEAT EXCHANGERS

2001 ◽  
Author(s):  
Arsalan Razani ◽  
Kwang J Kim
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):  
Guanmin Zhang ◽  
Guanqiu Li ◽  
Wei Li

Experimental and theoretical investigations of water-side fouling have been performed inside four corrugated plate heat exchangers. They have different geometric parameters, such as plate height, plate spacing, and plate angle. Heat transfer coefficients and friction factors have been obtained in clean tests. Composite fouling experiments have also been performed. The tests are primarily focused on the effects of average velocity. Scanning electron microscope (SEM) was used to investigate the microscopic structures of composite fouling and analyze the fouling characteristics in composite fouling tests. The plate heat exchanger with the largest de and height to pitch ratio shows the best anti-fouling performance.


Author(s):  
Merrill A. Wilson ◽  
Michele Bullough ◽  
Kriston Brooks ◽  
Kurt Recknagle

Efficiency and emissions of advanced gas turbine power cycles can be improved by incorporating high-temperature ceramic heat exchangers. In cooperation with the DOE, a highly effective microchannel ceramic recuperator for a microturbine is under development. In this recuperator, the use of microchannel architecture will improve heat transfer and provide a more uniform temperature distribution. This will result in overall higher productivity per unit volume compared to conventional hardware. The use of ceramic for the recuperator will allow higher temperature operation than available in conventional microturbines. Based on a model for a typical microturbine, these changes may improve the overall system efficiency from about 27% to over 40%.


Author(s):  
Marco Torresi ◽  
Alessandro Saponaro ◽  
Sergio Mario Camporeale ◽  
Bernardo Fortunato

The prediction of the performance of HRSG (Heat Recovery Steam Generator) by means of CFD codes is of great interest, since HRSGs are crucial elements in gas turbine combined cycle power plants, and in CHP (combined heat and power) cycles. The determination of the thermo-fluid dynamic pattern in HRSGs is fundamental in order to improve the energy usage and limit the ineffectiveness due to non-homogeneous flow patterns. In order to reduce the complexity of the simulation of the fluid flow within the HRSG, it is useful modeling heat exchangers as porous media zones with properties estimated using pressure drop correlations for tube banks. Usually, air-side thermo-fluid dynamic characteristics of finned tube heat exchangers are determined from experimental data. The aim of this work is to develop a new procedure, capable to define the main porous-medium non-dimensional parameters (e.g., viscous and inertial loss coefficients; porosity; volumetric heat generation rate; etc...) starting from data obtained by means of accurate three-dimensional simulations of the flow through tube banks. Both finned and bare tube banks will be considered and results presented. The analysis is based on a commercial CFD code, Fluent v.6.2.16. In order to validate the proposed procedure, the simulation of an entire fired HRSG of the horizontal type developed by Ansaldo Caldaie for the ERG plant at Priolo (Italy) has been performed and results have been compared with their data.


2015 ◽  
Vol 64 ◽  
pp. 23-32 ◽  
Author(s):  
Anders Austegard ◽  
Mayukh Bandopadhyay ◽  
Sigurd Weidemann Løvseth ◽  
Amy Brunsvold

Sign in / Sign up

Export Citation Format

Share Document