A FIRST APPROACH TO MODELLING A STEAM GENERATOR BASED ON HEAT EXCHANGERS NETWORK METHOD

2019 ◽  
Author(s):  
Augusto Delavald Marques ◽  
Caroline Mével ◽  
Paulo Smith Schneider ◽  
Jéssica Duarte ◽  
Guilherme Barth Rossi
Keyword(s):  
Steam Generator ◽  
Heat Exchangers ◽  
Network Method

Simulation and Optimization of Combined Cycle Power Cycles Through HRSG’s Heat Exchangers Arrangement and Parameters for Exergy and Cost

2012 ◽  
Author(s):  
Ravin G. Naik ◽  
Chirayu M. Shah ◽  
Arvind S. Mohite
Keyword(s):  
Power Plant ◽  
Steam Generator ◽  
Heat Exchangers ◽  
Heat Recovery ◽  
Second Law Of Thermodynamics ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Exergetic Efficiency ◽  
Power Cycles ◽  
Combined Cycle Power Plant

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.

Proven Concepts for LLW-Treatment of Large Components for Free-Release and Recycling

2007 ◽  
Author(s):  
Lena Bergstro¨m ◽  
Maria Lindberg ◽  
Anders Lindstro¨m ◽  
Bo Wirendal ◽  
Joachim Lorenzen
Keyword(s):  
Steam Generator ◽  
Heat Exchangers ◽  
Tube Bundle ◽  
Pilot Project ◽  
Initial Weight ◽  
Steam Generators ◽  
Huge Number ◽  
Material Recycling ◽  
Waste Production ◽  
Sampling Program

This paper describes Studsvik’s technical concept of LLW-treatment of large, retired components from nuclear installations in operation or in decommissioning. Many turbines, heat exchangers and other LLW components have been treated in Studsvik during the last 20 years. This also includes development of techniques and tools, especially our latest experience gained under the pilot project for treatment of one full size PWR steam generator from Ringhals NPP, Sweden. The ambition of this pilot project was to minimize the waste volumes for disposal and to maximize the material recycling. Another objective, respecting ALARA, was the successful minimization of the dose exposure to the personnel. The treatment concept for large, retired components comprises the whole sequence of preparations from road and sea transports and the management of the metallic LLW by segmentation, decontamination and sorting using specially devised tools and shielded treatment cell, to the decision criteria for recycling of the metals, radiological analyses and conditioning of the residual waste into the final packages suitable for customer-related disposal. For e.g. turbine rotors with their huge number of blades the crucial moments are segmentation techniques, thus cold segmentation is a preferred method to keep focus on minimization of volumes for secondary waste. Also a variety of decontamination techniques using blasting cabinet or blasting tumbling machines keeps secondary waste production to a minimum. The technical challenge of the treatment of more complicated components like steam generators also begins with the segmentation. A first step is the separation of the steam dome in order to dock the rest of the steam generator to a specially built treatment cell. Thereafter, the decontamination of the tube bundle is performed using a remotely controlled manipulator. After decontamination is concluded the cutting of the tubes as well as of the shell is performed in the same cell with remotely controlled tools. Some of the sections of steam dome shell or turbine shafts can be cleared directly for unconditional reuse without melting after decontamination and sampling program. Experience shows that the amount of material possible for clearance for unconditional use is between 95 – 97% for conventional metallic scrap. For components like turbines, heat exchangers or steam generators the recycling ratio can vary to about 80–85% of the initial weight.

Dual Receiver Concept for Solar Towers up to 100 MW

2005 ◽  
Vol 128 (3) ◽  
pp. 293-301 ◽  
Author(s):  
M. Eck ◽  
R. Buck ◽  
M. Wittmann
Keyword(s):  
Power Plant ◽  
Power Consumption ◽  
Steam Generator ◽  
Thermal Efficiency ◽  
Heat Exchangers ◽  
Thermal Power Plant ◽  
Thermal Power ◽  
Solar Thermal Power ◽  
Hot Air ◽  
Central Receiver

The dual receiver concept presented in this paper improves the adaptation of the central receiver to the steam cycle in a solar thermal power plant. By combination of an open volumetric air heater and a tubular evaporator the dual receiver concept profits from the advantages of these two concepts while their characteristic problems are avoided. The water is evaporated directly in the tubular steam generator; preheating and superheating are done in heat exchangers by using the hot air from the volumetric receiver. This paper presents a concept study that extends previous work on the 10MWel level (Buck et al., 2004, “Dual Receiver Concept for Solar Towers,” Proc. 12th Solar PACES Int. Symposium, Oct. 6–8, Oaxaca, Mexico) to a level of 100MWel, which is the expected power range of future plants. The results confirm the benefits of the new concept, resulting from higher thermal efficiency of the receiver and lower parasitic power consumption. The annual mean efficiency is increased from 13% to 16%. Advantageous are also the reduced thermal loads in the receiver components.

scholarly journals Continuous-wave radar to detect defects within heat exchangers and steam generator tubes.

2003 ◽  
Author(s):  
Bahram Nassersharif ◽  
Thurlow Washburn Howell Caffey ◽  
Russell P Jedlicka ◽  
Gabe V Garcia ◽  
Gary Eugene Rochau
Keyword(s):  
Steam Generator ◽  
Heat Exchangers ◽  
Continuous Wave ◽  
Wave Radar ◽  
Steam Generator Tubes

Thorough Chemical Decontamination MEDOC®: An Effective Way to Reduce Metallic Waste Volume of the Dismantled Materials

2001 ◽  
Author(s):  
Mathieu Ponnet ◽  
Michel Klein ◽  
André Rahier ◽  
Luc Noynaert ◽  
Gérard Aleton
Keyword(s):  
Radioactive Waste ◽  
Steam Generator ◽  
Heat Exchangers ◽  
Batch Process ◽  
Close Collaboration ◽  
Industrial Installation ◽  
Metallic Material ◽  
Technical Aspects ◽  
Chemical Decontamination ◽  
Decontamination Solution

Abstract The dismantling of the BR3-PWR reactor leads to the production of large masses of contaminated metallic pieces, including structural materials, primary pipings, tanks and heat exchangers. One of the main objectives is to demonstrate that we can minimise the volume of radioactive waste in an economical way, by the use of alternative waste routes, such as recycling of material in the nuclear world, free release of material in the conventional industry after melting or free release of material after thorough decontamination. The SCK•CEN launched a decontamination program with the aim to free release as much of the dismantled metallic material as possible. The selected chemical decontamination process, so-called MEDOC® (MEtal Decontamination by Oxidation with Cerium), is based on the use of cerium IV as strong oxidant in sulphuric acid with continuous regeneration using ozone. An industrial installation has been designed and constructed in close collaboration with Framatome-France. This installation started to operate in September 1999 for the treatment of the metallic pieces arising from the dismantling of the BR3 reactor. Since the installation starts up, 21 tons of contaminated material has been treated batchwise with success. Up to now, MEDOC® has been accomplished as a batch process in which the decontamination reactor is loaded with a basket containing the contaminated material. The SCK•CEN is now considering the possibility of using the MEDOC plant to decontaminate large components before cutting them, such as the BR3 -steam generator and the pressurizer. The decontamination solution will be circulated between the MEDOC plant and the steam generator during the consecutive decontamination cycles. Each cycle will comprises a decontamination step followed by a regeneration step. For the steam generator, 30 cycles are estimated to be needed to reach the free release level after melting. The decontamination studies of large components are ongoing and take into account the technical aspects, the radiological and classical safety aspects, as well as financial aspects.

Dual Receiver Concept for Solar Towers up to 100MW

Solar Energy ◽  
2005 ◽  
Author(s):  
R. Buck ◽  
M. Eck ◽  
M. Wittmann
Keyword(s):  
Power Plant ◽  
Power Consumption ◽  
Steam Generator ◽  
Thermal Efficiency ◽  
Heat Exchangers ◽  
Thermal Power Plant ◽  
Thermal Power ◽  
Solar Thermal Power ◽  
Hot Air ◽  
Central Receiver

The Dual Receiver Concept presented in this paper improves the adaptation of the central receiver to the steam cycle in a solar thermal power plant. By combination of an open volumetric air heater and a tubular evaporator the Dual-Receiver Concept profits from the advantages of these two concepts while their characteristic problems are avoided. The water is evaporated directly in the tubular steam generator, preheating and superheating is done in heat exchangers by using the hot air from the volumetric receiver (Fig. 1). This paper presents a concept study that extends previous work on the 10 MWel level (Buck et al. 2004) to a level of 100 MWel which is the expected power range of future plants. The results confirm the benefits of the new concept, resulting from higher thermal efficiency of the receiver and lower parasitic power consumption. The annual mean efficiency is increased from 13% to 16%. Advantageous are also the reduced thermal loads in the receiver components.

The Use of Porous Baffles to Control Acoustic Vibrations in Crossflow Tubular Heat Exchangers

1983 ◽  
Vol 105 (4) ◽  
pp. 751-758 ◽  
Author(s):  
K. P. Byrne
Keyword(s):  
Heat Exchanger ◽  
Steam Generator ◽  
Heat Exchangers ◽  
Heat Recovery ◽  
Flow Resistance ◽  
Acoustic Vibration ◽  
Acoustic Vibrations ◽  
Optimum Location ◽  
Tubular Heat Exchanger ◽  
Specific Flow

This paper describes how a single porous baffle can be used to prevent the occurrence of acoustic vibration in a crossflow tubular heat exchanger. A method for determining the optimum location and the optimum specific flow resistance of the porous baffle is presented. Finally, a description of how a porous baffle was successfully applied to control acoustic vibration which was occurring in the heat recovery region of a 375-MW brown coal steam generator is given.

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