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

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.

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Frantisek L. Eisinger ◽  
Robert E. Sullivan

Based on recent laboratory experimental data by Feenstra et al. (2004, “The Effects of Duct Width and Baffles on Acoustic Resonance in a Staggered Tube Array,” in Proceedings of the Eighth International Conference on Flow-Induced Vibration FIV 2004, E. de Langre and F. Axisa, eds., Paris France, Jul. 6–9, pp. 459–464; 2006, “A Study of Acoustic Resonance in a Staggered Tube Array,” ASME J. Pressure Vessel Technol., 128, pp. 533–540), it has been determined that for larger test section widths, the maximum acoustic pressures generated during acoustic resonance were greater by more than a factor of 4 than those predicted by Blevins and Bressler (1993, “Experiments on Acoustic Resonance in Heat Exchanger Tube Bundles,” J. Sound Vib., 164, 503–533). We have evaluated a great number of resonant and nonresonant cases from in-service experience of full size steam generator and tubular heat exchanger tube banks in order to see the general vibratory behavior of the full size units. Fifteen vibrating and twenty-seven nonvibrating cases were evaluated and compared to the Feenstra et al. relationship. It is shown that on average the results from the full size units correlate well with the relationship of Feenstra et al. A gap exists between the vibratory and the nonvibratory cases. The nonvibratory cases produce acoustic pressures, which are at or below the Blevins and Bressler relationship. From the results, it can be concluded that the full size units, regardless of their size and also acoustic mode, produce high acoustic pressures at resonance, with the maximum acoustic pressure on average more than 50–75 times higher than the input energy parameter defined by the product of Mach number and pressure drop through the tube bank. The results are tabulated and plotted for comparison.


Author(s):  
Frantisek L. Eisinger ◽  
Robert E. Sullivan

In the previous publications by Eisinger, F.L., Francis, J.T., and Sullivan, R.E., 1996, “Prediction of Acoustic Vibration in Steam Generator and Heat Exchanger Tube Banks”, ASME Journal of Pressure Vessel Technology, Vol. 118, pp. 221–236 and Eisinger, F.L. and Sullivan, R.E., 1996, “Experience with Unusual Acoustic Vibration in Heat Exchanger and Steam Generator Tube Banks”, Journal of Fluids and Structures, Vol. 10, pp. 99–107, prediction criteria for acoustic vibration or acoustic resonance were formulated utilizing flow and acoustic parameters derived from operating steam generator tube banks. Various parameters were used in those formulations, including the dominant parameter MΔp where M is the Mach number of the crossflow through the tube bank and Δp is the pressure drop through the tube bank. Here we present further evidence derived from operating experience of full size steam generator and tubular heat exchanger tube banks of which 19 experienced acoustic vibration or acoustic resonance and 27 experienced no vibration or no acoustic resonance within the operating flow range. The present data show that the decisive parameter predicting the acoustic vibration or acoustic resonance of a tube bank is the acoustic particle velocity. The acoustic particle velocity separates the acoustically vibrating banks from those non-vibrating very clearly. The behavior is demonstrated graphically showing the dimensionless acoustic particle velocity as a function of input energy parameter MΔp, Mach number M, Reynolds number Re and also Helmholtz number He = MS where S is the Strouhal number. This finding indicates that the acoustic particle velocity criterion shall be used in conjunction with the previously used criteria as the basis for the prediction of acoustic resonance in full size steam generator and tubular heat exchanger tube banks.


Author(s):  
J. P. Hughes ◽  
T. E. R. Jones ◽  
P. W. James

This paper describes numerical simulations and experimental measurements of isothermal laminar flow on the shell side of a model tubular heat exchanger, for both Newtonian and non-Newtonian fluids. Commercially available computational fluid dynamics software is used for the simulations, which are shown to be in good agreement with experimental measurements of shear rate and pressure drop. The simulations can then be used to provide a detailed description of the laminar shell-side flow in the model tubular heat exchanger. The motivation for this work stems from interest in the food processing industry in using tubular heat exchangers in heat recovery mode for medium viscosity food products. In this mode, the food product flows on the shell side as well as through the tubes. The shell-side flow is then laminar and aspects of the performance of the heat exchanger may be unsatisfactory. The work described in this paper forms part of a wider study in which validated numerical simulations are used in the design of tubular heat exchangers operating in heat recovery mode for medium viscosity food products.


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.


2001 ◽  
Author(s):  
Cristóbal Cortés ◽  
Luis I. Díez ◽  
Antonio Campo

Abstract Practical calculation of the heat-recovery sections of large-size boilers is still based on approximate methods. On the one hand, CFD-based models cannot directly handle the geometric intricacy of tube bundles, and thus rely on volume-averaged source terms that demand empirical input. On the other hand, the standard, lumped heat exchanger calculation, which can be a far simpler and more robust alternative, fails in several important aspects, mainly related to the effects of thermal radiation and the coupling between several sections. In this paper, we consider the diverse sections of a coal-fired utility boiler as a case study to show how to deal with these shortcomings. Under the objective of developing a simple monitoring method, we extend the traditional heat exchanger model to take into account most of the peculiarities of boiler superheaters, reheaters and economizers. Techniques range from the re-examination of analytical solutions to the auxiliary use of CFD calculations. The models are assembled to simulate the thermal performance of the boiler as a whole unit. Results are validated against actual measurements taken at a thermoelectric plant.


2021 ◽  
pp. 3-19
Author(s):  
Dusan P. Sekulic

Abstract Heat exchangers are devices used to transfer thermal energy between two or more fluids, between a solid surface and a fluid, or between a solid particulate and a fluid at different temperatures. This article first addresses the causes of failures in heat exchangers. It then provides a description of heat-transfer surface area, discussing the design of the tubular heat exchanger. Next, the article discusses the processes involved in the examination of failed parts. Finally, it describes the most important types of corrosion, including uniform, galvanic, pitting, stress, and erosion corrosion.


1999 ◽  
Vol 65 (640) ◽  
pp. 4633-4639 ◽  
Author(s):  
Keiichi KATAYAMA ◽  
Mamoru TSUBOI ◽  
Takayoshi KAWAOKA ◽  
Kazuhide OTA ◽  
Yuichi SATO

Author(s):  
C. F. McDonald

Increased emphasis is being placed on the regenerative gas turbine cycle, and the utilization of waste heat recovery systems, for improved thermal efficiency. For such systems there are modes of engine operation, where it is possible for a metal fire to occur in the exhaust heat exchanger. This paper is intended as an introduction to the subject, more from an engineering, than metallurgical standpoint, and includes a description of a series of simple tests to acquire an understanding of the problem for a particular application. Some engine operational procedures, and design features, aimed at minimizing the costly and dangerous occurrence of gas turbine heat exchanger fires, are briefly mentioned.


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