Avoiding Thermoacoustic Vibration in Burner/Furnace Systems

2002 ◽  
Vol 124 (4) ◽  
pp. 418-424 ◽  
Author(s):  
Frantisek L. Eisinger ◽  
Robert E. Sullivan
Keyword(s):  
Steam Generator ◽  
Mode Shape ◽  
Critical Value ◽  
Acoustic Mode ◽  
Full Scale ◽  
Large Temperature ◽  
Temperature Ratio ◽  
Combined System ◽  
Furnace Gases ◽  
Tube Type

Burner/furnace systems are generally sensitive to thermoacoustic vibration due to the presence of large temperature differentials between the cold burner air and the hot furnace gases. The systems are predicted to vibrate when the temperature ratio between the hot and cold components reaches a critical value and when the acoustic mode shape of the combined system develops into a Rijke or a Sondhauss tube type. Original full-scale large-utility steam generator systems which vibrated in operation and modified systems resisting the vibration are described and explained. Guidelines for designing systems resistant to thermoacoustic vibration are also given to aid the designers.

scholarly journals A Novel Bio-Eco Technology Combined System for Rural Domestic Wastewater Treatment in a Tourism Area: A Full-Scale Study

2009 ◽  
Vol 26 (9) ◽  
pp. 1419-1427 ◽  
Author(s):  
Hanwen Liang ◽  
Junxin Liu ◽  
Xuesong Guo ◽  
Baoqing Shan ◽  
Jingzhu Zhao ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Domestic Wastewater ◽  
Full Scale ◽  
Combined System ◽  
Domestic Wastewater Treatment

Eliminating Thermoacoustic Oscillations in Heat Exchanger and Steam Generator Systems

1999 ◽  
Vol 121 (4) ◽  
pp. 444-452 ◽  
Author(s):  
F. L. Eisinger
Keyword(s):  
Heat Exchanger ◽  
Temperature Gradient ◽  
Steam Generator ◽  
Critical Value ◽  
Duct Systems ◽  
Furnace Burner ◽  
Thermoacoustic Oscillations

Systems comprised of hot and cold components containing gaseous fluids may be subject to thermoacoustic oscillations if the temperature gradient between the two components exceeds a critical value. An evaluation of the Sondhauss-type and the Rijke-type thermoacoustic oscillations in combined turbine/heat exchanger/duct systems and furnace/burner systems will be presented. Parameters which will reduce or eliminate the likelihood of thermoacoustic oscillations in such systems are identified and discussed in this paper.

A Complex 3D Acoustic Induced Vibration of a Low NOx Refinery Boiler

2006 ◽  
Author(s):  
Robert J. McKee ◽  
Joe Pantermuehl ◽  
Marlan Jarzombek ◽  
Ryan Gernentz ◽  
Doug Haveman
Keyword(s):  
Mode Shape ◽  
Field Data ◽  
Acoustic Mode ◽  
Acoustic Modeling ◽  
Normal Operation ◽  
Dynamic Measurements ◽  
Wide Range ◽  
Steam Boilers ◽  
Low Nox Combustion ◽  
Acoustic Responses

An increasing number of refinery and other large process steam boilers are being installed with or converted to low NOx combustion. The primary result of low NOx combustion is reduced emissions; however, this type of combustion can also lead to unsteady pressures (pulsation), rumbles, and vibrations of boiler components and walls. This paper reports on an investigation of vibrations that were observed on the walls of a new low NOx boiler during its commissioning. Dynamic measurements and 3D acoustic modeling were used to identify and define the fluid force (acoustic) induced vibration problem and to design baffles to eliminate the specific complex acoustic mode that was causing the vibrations. Vibration measurements were recorded at numerous locations on the exterior walls of the boiler so that variations in magnitude and phase of the wall motions at different locations could be determined. The mode shape of the boiler motion was mapped from this data. Pulsation measurements were made on pressure taps at several locations around the boiler. The pulsation data defined the amplitude and phase relationships of the combustion and flow induced acoustic responses within the boiler. A 3D acoustic model of the boiler was created with internal gas properties including the speed of sound based on temperature distribution within the boiler. The model results were compared to measured data and the complex mode of the troublesome acoustic response was identified. Simple symmetric centerline baffles had been attempted by the boiler supplier without eliminating or reducing the vibrations and noise of the boiler. Based on the complex acoustic mode shape of the pulsation within the boiler as identified by the model results that agreed with field data, specific extended baffles were designed and installed to eliminate the vibrations that had been observed. Smooth operation of the low NOx boiler over a wide range of normal operation not previously obtained was achieved with the new baffles installed. The process of dynamic measurements and 3D acoustic modeling to match field data and confirm the mode shape of acoustic responses within a boiler, as described in this paper, can be used to resolve vibration problems including complex situations that are not solvable by other means.

Acoustic Vibration Behavior of Full Size Steam Generator and Tubular Heat Exhanger In-Line Tube Banks: A Brief Note

2005 ◽  
Author(s):  
Franktisek L. Eisinger ◽  
Robert E. Sullivan
Keyword(s):  
Steam Generator ◽  
Energy Parameter ◽  
Acoustic Resonance ◽  
Acoustic Vibration ◽  
Acoustic Mode ◽  
Tubular Heat Exchanger ◽  
Full Size ◽  
Tube Banks ◽  
Exchanger Tube ◽  
Recent Laboratory

Based on recent laboratory experimental data by Feenstra et al. [1],[2] 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 four than those predicted by Blevins and Bressler [3]. We have evaluated a great number of resonant and non-resonant cases from inservice 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 non-vibrating 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 Feenstra et al. relationship. A gap exists between the vibratory and the non-vibratory cases. The non-vibratory 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 fifty to seventy five 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.

Blading Aerodynamics Design Optimization With Mechanical and Aeromechanical Constraints

2006 ◽  
Author(s):  
H.-D. Li ◽  
L. He ◽  
Y. S. Li ◽  
R. Wells
Keyword(s):  
Design Optimization ◽  
Mode Shape ◽  
Natural Frequencies ◽  
Present Finding ◽  
Critical Value ◽  
Design Parameters ◽  
Present System ◽  
Peak Efficiency ◽  
Aerodynamic Damping ◽  
Harmonic Perturbation

A blading design optimization system has been developed using an aeromechanical approach and harmonic perturbation method. The developed system has the capability to optimize aero-thermal performance with constraints of mechanical and aeromechanical integrity at the same time. ‘Aerodynamic mode shape’ is introduced to describe geometry deformation which can effectively reduce the number of design parameters while preserving surface smoothness. Compared to the existing design optimization practices, the present system is simpler, more accurate and effective. A redesign practice of the NASA rotor-67 at the peak efficiency point shows that the aero thermal efficiency can be improved by 0.4%, whilst the maximum static stress has been increased by 33%. Aeromechanical analysis of the optimized blade shows that the aerodynamic damping of the least stable first flap mode is still well above the critical value though the natural frequencies of the first 5 modes have been reduced by 1∼4%. The present finding highlights the need for more concurrent integrations of mechanics, aerodynamics and aeromechanics design optimization.

Thermoacoustic Oscillations in Multipath Heated Fuel Circuits

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Steven Hunt ◽  
Stephen Heister
Keyword(s):  
Characteristic Length ◽  
Pressure Oscillation ◽  
Acoustic Mode ◽  
Large Temperature ◽  
Phase Lag ◽  
Flow Conditions ◽  
Fuel Flow ◽  
Lower Frequency Mode ◽  
Thermoacoustic Oscillations ◽  
Fuel Tube

Pressure oscillations in supercritical jet-A fuel flowing through four parallel heated tubes connected to common manifolds have been observed in this study. Tests were performed with fuel inlet temperatures ranging from 70 °F to 700 °F, and fuel pressures ranging from 360 to 700 psi. Total fuel flow rate ranged from 5 to 55 lb/h. Tubes were heated by blowing 800–950 °F nitrogen over them. Acoustic-mode oscillations, typically ranging from 100 to 500 Hz, occurred only when a large temperature gradient was created inside the heated fuel tubes. Pressure oscillation amplitudes ranged from 0.1 to 1.0 psi. Oscillations at the inlet and outlet manifolds that were caused by a mode with the characteristic length of a single fuel tube were separated by a phase lag that was a function of the manifold cross-passage diameter. A lower frequency mode was also observed, which had a characteristic length based on the summed lengths of a single fuel tube and a single manifold passage. An acoustic simulation using the comsol acoustics module was performed to predict frequencies based on geometry and flow conditions of the experiment.

A Review of Acoustic Vibration Criteria Compared to In-Service Experience With Steam Generator In-Line Tube Banks

1994 ◽  
Vol 116 (1) ◽  
pp. 17-23 ◽  
Author(s):  
F. L. Eisinger ◽  
R. E. Sullivan ◽  
J. T. Francis
Keyword(s):  
Steam Generator ◽  
Acoustic Vibration ◽  
Acoustic Mode ◽  
Steam Generators ◽  
Transverse Acoustic ◽  
Predictive Methods ◽  
Theoretical Predictions ◽  
Tube Banks ◽  
Prediction Criteria ◽  
Operating Steam

Tube banks of operating steam generators were evaluated for resonant acoustic vibration in the transverse acoustic mode, using a number of published vibration criteria and a range of Strouhal numbers. Theoretical predictions based on computer simulations were compared to available experimental data for nonvibrating and vibrating banks. It is shown that large differences exist among the predictive methods, and most do not fully predict acoustic resonances. On a relative basis, prediction criteria of Y. N. Chen and Grotz and Arnold, with Fitzhugh-Strouhal numbers, offer the best results for steam generator tube banks.

The FEM Simulation and Full-Scale Blast Tests for Crack Deceleration in Gas Pipeline

2006 ◽  
Vol 306-308 ◽  
pp. 85-90
Author(s):  
Chun Yong Huo ◽  
Xiao Bin Yang ◽  
Zhuo Zhuang ◽  
Julaiti Maitirouzi ◽  
Y.R. Feng ◽  
...  
Keyword(s):  
Fem Simulation ◽  
Critical Issue ◽  
Critical Value ◽  
Full Scale ◽  
Gas Pipeline ◽  
Opening Angle ◽  
Balance Theory ◽  
Dynamic Propagation ◽  
Crack Tip Opening Angle ◽  
Crack Tip Opening

Preventing pipeline from rapid crack propagation is a critical issue to avoid casualties and disasters. In this paper, by combining the energy balance theory with FEM simulation and arrest criteria, the numerical analysis is developed to solve the problem of crack dynamic propagation in gas pipeline. This simulation, in combination with the full-scale blast tests, provides a broad prediction of the dynamic fracture process. The crack tip opening angle (CTOA) criterion is consummated through the comparison between CTOA in FEM calculation and the critical value of (CTOA)C obtained by the experiment. The result of the simulation for the crack speed and location is consistent with data by Alliance and Japanese full-scale blast tests.

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