Thermal-Hydraulic Characteristics of Twisted Elliptical Tube Bundle in Staggered Arrangement

2021 ◽  
Author(s):  
Xiuzhen Li ◽  
Lin Wang ◽  
Rong Feng ◽  
Zhanwei Wang ◽  
Dongsheng Zhu
Keyword(s):  
Tube Bundle ◽  
Hydraulic Characteristics ◽  
Staggered Arrangement

Flow-Induced Vibration of Cross-Shaped Tube Bundle: The Effect of Tube Bundle Arrangement

2003 ◽  
Author(s):  
Fumio Inada ◽  
Takashi Nishihara ◽  
Akira Yasuo ◽  
Ryo Morita ◽  
Akihiro Sakashita ◽  
...  
Keyword(s):  
Correlation Length ◽  
Random Vibration ◽  
Tube Bundle ◽  
Cross Flow ◽  
Flow Induced Vibration ◽  
Power Spectral ◽  
Shaped Tube ◽  
Excited Vibration ◽  
Power Spectral Densities ◽  
Staggered Arrangement

A cross-shaped tube bundle is proposed for the lower plenum structure in the next-generation LWR. The effect of tube bundle arrangement on the flow-induced vibration characteristics of the cross-shaped tube bundle in cross flow was considered experimentally. Regarding random vibration, the power spectral density of the fluid force of the staggered arrangement as well as the correlation length was measured and those of the normal arrangement were compared with those of the staggered arrangement. Regarding self-excited vibration, vibration response was compared. The trend of the power spectral densities, correlation length, and the critical velocity of the normal arrangement were similar to those of the staggered arrangement.

Performance Analysis of a Modular Air Cooled Condenser for a Concentrated Solar Power Plant

2012 ◽  
Author(s):  
J. Moore ◽  
R. Grimes ◽  
E. J. Walsh
Keyword(s):  
Solar Power ◽  
Tube Bundle ◽  
Plant Performance ◽  
Test Facility ◽  
Air Cooling ◽  
Concentrated Solar Power ◽  
Staggered Arrangement ◽  
Fan Speed ◽  
Tube Banks ◽  
The Given

The use of air cooled condensers in power generation facilities is increasing in arid regions around the world. There is a specific requirement for more efficient air cooling technologies to be developed for Concentrated Solar Power (CSP) plants. This paper aims at determining the effects of various condenser design features on CSP plant output. In particular this paper considers a modular condenser and focuses on designing a suitable compact heat sink to be coupled with a variable speed fan array. Tube banks with radial fins have been used for decades to heat and cool gases and numerous correlations exist to predict the performance of such a heat exchanger. The initial design of this air-cooled condenser is essentially a tube bundle consisting of 6 rows of helically finned round tubes in an equilateral staggered arrangement. A laboratory-scale steady state test facility was designed to investigate the accuracy of the relevant correlations for the given design. Due to an undesired phenomenon which exists in multi-row condensers known as backflow, an investigation was performed to analyze the performance of the tube bank with fewer tube rows. The thermal and hydraulic performance for a tube bundle with a different number of tube rows was measured and found to be within 10–18% of the existing correlations. New correlations for heat transfer and pressure drop for the given design are presented for greater accuracy in the calculation of the condenser performance. These correlations, based on the measured data were combined with performance characteristics from a steam turbine to model the thermodynamic plant performance incorporating the various condenser designs. The investigation shows that for each condenser size, design and ambient temperature, an optimum fan speed exists which maximizes plant output. Further analysis shows that for a 1000 module condenser, a 4 row condenser results in the highest plant output, with a loss in efficiency due to condenser operation of 1.85%. A 2 row condenser also performs relatively well with 600 or more modules. This analysis shows that a condenser consisting of a series of such modules, can tightly control and optimize the net plant output power by simply varying fan speed.

Computational fluid dynamics investigation of thermal–hydraulic characteristics for a steam generator with and without tube support plates

2013 ◽  
Vol 227 (12) ◽  
pp. 2897-2911 ◽  
Author(s):  
Yuanlong Yang ◽  
Baozhi Sun ◽  
Yanjun Li ◽  
Liu Yang ◽  
Lusong Zheng
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Steam Generator ◽  
Tube Bundle ◽  
Flow Behavior ◽  
Hydraulic Characteristics ◽  
Dynamics Model ◽  
Flow Induced Vibration ◽  
Computational Fluid Dynamics Model ◽  
Vibration Damage

A three-dimensional computational fluid dynamics model with the thermal phase change model is used to investigate the thermal–hydraulic characteristics of a steam generator with and without quatrefoil tube support plates. The two types of modeled designs are a unit pipe with and one without tube support plates. The computational fluid dynamics simulations capture the boiling phenomena, vortex and recirculation distributions, and the periodic characteristics of the circumferential wall temperature in the regions surrounding the tube support plates. The cross-flow energy responsible for flow-induced vibration damage in the region of the U-bend tubes is obtained with the aid of these localized thermal–hydraulic distributions. A comparison between the key parameters of the unit pipe models with and without tube support plates clearly reveals the influence of tube support plates in guiding flow behavior and alleviating flow-induced vibration damage for a steam generator’s U-bend tube bundle. Therefore, this computational fluid dynamics model can provide technical support for optimizing tube support plate design and improving the thermal–hydraulic characteristics of steam generator.

Comparison Between Numerical and Experimental Gas Side Heat Transfer and Pressure Drop of a Tube Bank With Solid and Segmented Circular I-Fins

2012 ◽  
Author(s):  
Rene Hofmann ◽  
Heimo Walter
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Tube Bundle ◽  
Three Dimensional ◽  
Finned Tube ◽  
Three Dimensional Model ◽  
Finned Tubes ◽  
Numerical Predictions ◽  
Staggered Arrangement ◽  
Flow Experiments

In the present work, a comparison between numerical and experimental gas side heat transfer and pressure drop for a tube bundle with solid and segmented circular finned tubes in a staggered arrangement is investigated. For the numerical simulations a three dimensional model of the finned tube are applied. Renormalization group theory (RNG) based k–ε turbulence model was used to calculate the turbulent flow. Experiments have been carried out to validate the numerical predictions. The numerical results for the Nu-number and pressure drop coefficient show a good agreement with the data from measurement. A comparison between solid and segmented finned tubes from the global calculation of the Nu-numbers within the analyzed Re-range shows an enhancement by applying segmented finned tubes rather than finned tubes with solid fins.

MODELING THE HYDRAULIC CHARACTERISTICS OF DRAIN VALVE AND BURST FITTING OF AN AIRCRAFT ACCIDENT-RESISTANT FUEL SYSTEM

2020 ◽  
Vol 7 (3) ◽  
pp. 37-44
Author(s):  
KONSTANTIN NAPREENKO ◽  
◽  
ROMAN SAVELEV ◽  
ALEKSEY TROFIMOV ◽  
ANNA LAMTYUGINA ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Hydraulic Resistance ◽  
Hydraulic Calculation ◽  
Fuel System ◽  
Hydraulic Characteristics ◽  
System A ◽  
Ansys Cfx ◽  
Calculation Results ◽  
Scale Experiment ◽  
Aircraft Accident

The article discusses methods for determining the hydraulic resistance of units of an accident-resistant fuel system. A detailed description of the need to create such fuel systems for modern helicopters is given. The development of such systems today is impossible without the use of the method of mathematical modeling, which allows to qualitatively solve problems arising in the design process. To obtain accurate research results, it is necessary to have a complete description of all elements and assemblies of the system. Methods for determining the hydraulic characteristics of AFS elements using the drag coefficient, reference literature and CFD codes are considered. As the investigated AFS units, a drain valve and burst fitting were studied in the article. A hydraulic calculation of these AFS elements ware performed, the simulation results are presented in the ANSYS CFX software package. Also as the calculation results of bursting fitting, the pressure distribution fields of full and static pressure, velocity and streamlines are also shown. An experimental setup for validating the results obtained using the mathematical modeling method is considered, as well as a methodology for conducting a full-scale experiment to determine the hydraulic resistance of the unit. Materials have been prepared for inclusion in a one-dimensional mathematical model of an accident-resistant fuel system.

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