Effects of inclination and flow velocity on steam condensation consisting of air on tube bundle external surfaces

2021 ◽  
Vol 136 ◽  
pp. 103722
Author(s):  
Gonglin Li ◽  
Boyang Cao ◽  
Shuhang Zhou ◽  
Haozhi Bian ◽  
Ming Ding
Keyword(s):  
Flow Velocity ◽  
Tube Bundle ◽  
Steam Condensation

Steam condensation on tube-bundle in presence of non-condensable gas under free convection

2021 ◽  
Vol 178 ◽  
pp. 121619
Author(s):  
Jinhoon Kang ◽  
Jeongmin Moon ◽  
Youngchang Ko ◽  
Sang-Gyu Lim ◽  
Byongjo Yun
Keyword(s):  
Free Convection ◽  
Tube Bundle ◽  
Steam Condensation

A dataset of steam condensation over a double enhanced tube bundle under vacuum

2004 ◽  
Vol 24 (8-9) ◽  
pp. 1381-1393 ◽  
Author(s):  
T.H. Ooi ◽  
D.R. Webb ◽  
P.J. Heggs
Keyword(s):  
Tube Bundle ◽  
Steam Condensation ◽  
Enhanced Tube

Non-Condensable Gases Effect on Heat Transfer Processes Between Condensing Steam and Boiling Water in Heat Exchanger With Multirow Horizontal Tube Bundle

2010 ◽  
Author(s):  
A. V. Morozov ◽  
O. V. Remizov ◽  
A. A. Tsyganok
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Tube Bundle ◽  
Horizontal Tube ◽  
Boiling Water ◽  
Test Facility ◽  
Primary Circuit ◽  
Outer Diameter ◽  
Steam Condensation ◽  
Experimental Heat

The experimental investigations of non-condensable gases effect on the steam condensation inside multirow horizontal tube bundle of heat exchanger under heat transfer to boiling water were carried out at the large-scale test facility in the Institute for Physics and Power Engineering (IPPE). The experiments were carried out for natural circulation conditions in primary and secondary circuits of the facility at primary circuit steam pressure of Ps1 = 0.34 MPa. The experimental heat exchanger’s tube bundle consists of 248 horizontal coiled tubes arranged in 62 rows. Each row consists of 4 stainless steel tubes of 16 mm in outer diameter, 1.5 mm in wall thickness and of 10.2 m in length. The experimental heat exchanger was equipped with more than 100 thermocouples enabling the temperatures of primary and secondary facility circuits to be controlled in both tube bundle and in the inter-tubular space. The non-condensable gases with different density — nitrogen and helium were used in the experiments. The volumetric content of gases in tube bundle amounted to ε = 0.49. The empirical correlation for the prediction of the relative heat transfer coefficient k/k0 = f (ε) for steam condensation in steam-gas mixture was obtained.

scholarly journals Analisa Kinerja Aliran Fluida dalam Rangkaian Seri dan Paralel dengan Penambahan Tube Bundle pada Pompa Sentrifugal

2019 ◽  
Vol 3 (2) ◽  
pp. 71
Author(s):  
Muhammad Marzuky Saleh ◽  
Edi Widodo
Keyword(s):  
Flow Velocity ◽  
Tube Bundle ◽  
High Surface ◽  
Fluid Pressure ◽  
Discharge Flow ◽  
Flow Type ◽  
Pressure Discharge ◽  
Parallel Circuit ◽  
Parallel Tube ◽  
Pump House

Pump is a device used to move fluid from one place to another through the pipe media as a channel. The pump has 2 important components in its performance, namely: Impeller and pump house (casing). When the pump cannot meet the required capacity it can use series and parallel pump circuits to increase it. When moving the fluid to a high surface or high pressure it will have the specifications of the head and discharge. Fluid flow is a liquid that flows in a pipe. In flow there is fluid pressure and also flow type. There are 3 flow types, namely laminer, transition, turbulent. To reduce turbulence in the flow can be used Tube bundle which is a device consisting of several pipes that are tied together that are attached to a cross section in the pipe. This research was conducted in 4 testing stages, namely series circuit with additional tube bundle, series circuit without additional tube bundle, parallel circuit with additional tube bundle, parallel circuit without additional tube bundle. Each test takes fluid pressure, discharge, flow type. From the results of this study it was found that the parallel circuit pump with an additional tube bundle produces fluid pressure, discharge, flow velocity smaller than the series circuit, whereas when without additional the parallel tube pump bundle produces a fluid pressure, discharge, flow velocity greater than the circuit series, while for the flow type of this study is turbulent flow.

Different Type Tube Bundle Heat Transfer to Vertical Foam Flow

2007 ◽  
Author(s):  
Jonas Gylys ◽  
Stasys Sinkunas ◽  
Tadas Zdankus ◽  
Vidmantas Giedraitis
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Flow Velocity ◽  
Void Fraction ◽  
Tube Bundle ◽  
Auxiliary Equipment ◽  
Foam Flow ◽  
Flow Parameters ◽  
Tube Bundles ◽  
Foam Generator

Gas-liquid foam due to especially large inter-phase contact surface can be used as a coolant. An experimental investigation of the staggered and in-line tube bundles’ heat transfer to the vertically upward and downward laminar foam flow was performed. The experimental setup consisted of the foam generator, vertical experimental channel, tube bundles, measurement instrumentation and auxiliary equipment. It was determined dependency of heat transfer intensity on flow parameters: flow velocity, direction of flow, volumetric void fraction of foam and liquid drainage from foam. Apart of this, influence of tube position in the bundle to heat transfer was investigated. Foam flow structure, distribution of the foam’s local void fraction and flow velocity in cross-section of the channel were the main factors which influenced on heat transfer intensity of the different tubes. Experimental investigation showed that the heat transfer intensity of the frontal and further tubes of the bundles to vertical foam flow is different in comparison with one-phase fluid flow. The results of the experimental investigation are presented in this paper.

Experimental Identification of Fluid-Elastic Coupling Forces on a Square Tube Bundle Subjected to Single-Phase Cross-Flow

2016 ◽  
Author(s):  
Philippe Piteau ◽  
Xavier Delaune ◽  
Laurent Borsoi ◽  
Jose Antunes
Keyword(s):  
Flow Velocity ◽  
Single Phase ◽  
Tube Bundle ◽  
Cross Flow ◽  
Elastic Coupling ◽  
Coupling Coefficients ◽  
Flow Coupling ◽  
Modal Mass ◽  
Stiffness And Damping ◽  
Elastic Coefficients

The importance of fluid-elastic coupling forces in tube bundle vibrations is well documented and can hardly be over-emphasized, in view of their damaging potential. Even when adequate tube supports are provided to suppress fluid-elastic instabilities, the flow-coupling forces still affect the dynamical tube responses and remain a significant issue, in particular concerning the vibro-impact motions of tubes assembled using clearance supports. Therefore, the need remains for more advanced models of fluid-elastic coupling, as well as for experimental flow-coupling coefficients to feed and validate such models. In this work, we report an extensive series of experiments performed at CEA-Saclay leading to the identification of stiffness and damping fluid-elastic coefficients, for a 3×5 square tube bundle (D = 30 mm, P/D = 1.5) subjected to single-phase transverse flow. The bundle is rigid, except for the central tube which is mounted on a flexible suspension (two parallel steel blades) allowing for translation motions of the tube in the lift direction. The system is thus single-degree of freedom, allowing fluid-elastic instability to arise through a negative damping mechanism. The flow-coupling stiffness and damping coefficients, Kf(Vr) and Cf(Vr), are experimentally identified as functions of the reduced velocity Vr. Identification is achieved on the basis of changes in tube vibration frequency and reduced damping as a function of flow velocity, assuming a constant fluid added mass. In the present experiments, coefficient identification is performed well beyond the instability boundary, by using active control, thereafter allowing exploration of a significant range of flow velocity. The modal frequency and the modal mass of the system are respectively modified by changing the tube suspension stiffness, and/or by adding a mass to the system. We can thus assert how the fluid-elastic coefficients change, for this configuration, with these two system parameters, all other parameters being kept constant. The results obtained from the configurations tested suggest that formulations for coefficient reduction may be improved, in order to better collapse the identified data.

Critical Velocity of a Non-Linearly Supported Multi-Span Tube Bundle

2006 ◽  
Author(s):  
M. K. Au-Yang ◽  
J. A. Burgess
Keyword(s):  
Flow Velocity ◽  
Critical Velocity ◽  
Tube Bundle ◽  
Normal Modes ◽  
Cross Flow ◽  
Time History ◽  
Tube Bundles ◽  
Cross Flow Velocity ◽  
The Cross ◽  
The Time Domain

The phenomenon of fluid-elastic instability and the velocity at which a heat exchanger tube bundle becomes unstable, known as the critical velocity, was discovered and empirically determined based upon single-span, linearly supported tube bundles. In this idealized configuration, the normal modes are well separated in frequency with negligible cross-modal contribution to the critical velocity. As a result, a critical velocity can be defined and determined for each mode. In an industrial heat exchanger or steam generator, not only do the tube bundles have multiple spans, they are also supported in over-sized holes. The normal modes of a multi-span tube bundle are closely spaced in frequency, and the non-linear effect of the tube-support plate interaction further promotes cross-modal contribution to the tube responses. The net effect of cross-modal participation in the tube vibration is to delay the instability threshold. Tube bundles in industrial exchangers often have critical velocities far above what were determined in the laboratory based upon single-span, linearly supported tube bundles. In this paper, the authors attempt to solve this non-linear problem in the time domain, using a time history modal superposition method. Time history forcing functions are first obtained by inverse Fourier transform of the power spectral density function used in classical turbulence-induced vibration analyses. The fluid-structure coupling force, which is dependent on the cross-flow velocity, is linearly superimposed onto the turbulence forcing function. The tube responses are then computed by direct integration in the time domain. By gradually increasing the cross-flow velocity, a threshold value is obtained at which the tube response just starts to diverge. The value of the cross-flow velocity at which the tube response starts to diverge is defined as the critical velocity of this non-linearly supported, multi-span tube bundle.

Fluid-Elastic Vibration of Cross-Shaped Tube Bundle in Mixed Cross and Parallel Flow: Measurement of Gap Flow Velocity and Vibration Characteristics

2006 ◽  
Author(s):  
Fumio Inada ◽  
Takashi Nishihara ◽  
Jun Mizutani
Keyword(s):  
Flow Velocity ◽  
Tube Bundle ◽  
Cross Flow ◽  
Vibration Characteristics ◽  
Parallel Flow ◽  
Water Tunnel ◽  
Flow Component ◽  
Shaped Tube ◽  
Excited Vibration ◽  
Flow Components

A cross-shaped control rod guide tube bundle is proposed for the lower plenum structure in the next-generation LWR, ABWR-II. In our previous studies, we measured the local fluid excitation forces acting on a cross-shaped tube bundle as well as the self-excited vibration characteristics in pure cross flow in water tunnel tests. In the reactor conditions, the flow field around the tube bundles contains mixed cross and parallel flow components. In this study, water tunnel tests under mixed cross and parallel flow conditions were preformed to understand the influence of the balance of parallel and cross flow components on vibration response. The distributions of the flow direction and flow velocity in the gap between the adjacent tubes were measured with circular Pilot tubes in detail. It was found that the critical flow velocity of self-excited vibration was not influenced by the parallel flow component, but depended only on the cross flow component.

scholarly journals Fluid-Elastic Instability Tests on Parallel Triangular Tube Bundles with Different Mass Ratio Values under Increasing and Decreasing Flow Velocities

2016 ◽  
Vol 2016 ◽  
pp. 1-20
Author(s):  
Xu Zhang ◽  
Bin Jiang ◽  
Luhong Zhang ◽  
Xiaoming Xiao
Keyword(s):  
Stainless Steel ◽  
Flow Velocity ◽  
Tube Bundle ◽  
Steel Tube ◽  
Stainless Steel Tube ◽  
Hysteresis Phenomenon ◽  
Elastic Instability ◽  
Nonlinear Hysteresis ◽  
Tube Bundles ◽  
Flow Velocities

To study the effects of increasing and decreasing flow velocities on the fluid-elastic instability of tube bundles, the responses of an elastically mounted tube in a rigid parallel triangular tube bundle with a pitch-to-diameter ratio of 1.67 were tested in a water tunnel subjected to crossflow. Aluminum and stainless steel tubes were tested, respectively. In the in-line and transverse directions, the amplitudes, power spectrum density functions, response frequencies, added mass coefficients, and other results were obtained and compared. Results show that the nonlinear hysteresis phenomenon occurred in both tube bundle vibrations. When the flow velocity is decreasing, the tubes which have been in the state of fluid-elastic instability can keep on this state for a certain flow velocity range. During this process, the response frequencies of the tubes will decrease. Furthermore, the response frequencies of the aluminum tube can decrease much more than those of the stainless steel tube. The fluid-elastic instability constants fitted for these experiments were obtained from experimental data. A deeper insight into the fluid-elastic instability of tube bundles was also obtained by synthesizing the results. This study is beneficial for designing and operating equipment with tube bundles inside, as well as for further research on the fluid-elastic instability of tube bundles.

Pressure and shear stress analysis in a normal triangular tube bundle based on experimental flow velocity field

2020 ◽  
Vol 42 (4) ◽  
Author(s):  
Douglas Martins Rocha ◽  
Fabio Toshio Kanizawa ◽  
Kosuke Hayashi ◽  
Shigeo Hosokawa ◽  
Akio Tomiyama ◽  
...  
Keyword(s):  
Shear Stress ◽  
Velocity Field ◽  
Stress Analysis ◽  
Flow Velocity ◽  
Tube Bundle ◽  
Flow Velocity Field
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