• Title, Summary, Keyword: chimney

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Chimney Construction (굴뚝의 설계)

  • Jang, Gi-In
    • Korean Architects
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    • v.3 no.8
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    • pp.27-32
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    • 1968
  • This article discusses at a basic level the process of chimney construction. The concept, design, and operation can be understood easily. This, of course, is the first step to orderly construction. The selection of the boiler as to type, capacity, etc. was summarized in brief. The over all planning of the boiler and chimney together was the main object of this article. The architectural books covering this subject are very technical and this article tries to make the understanding of the basic principles more easy for the beginner in architecture.

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The influence of model surface roughness on wind loads of the RC chimney by comparing the full-scale measurements and wind tunnel simulations

  • Chen, Chern-Hwa;Chang, Cheng-Hsin;Lin, Yuh-Yi
    • Wind and Structures
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    • v.16 no.2
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    • pp.137-156
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    • 2013
  • A wind tunnel test of a scaled-down model and field measurement were effective methods for elucidating the aerodynamic behavior of a chimney under a wind load. Therefore, the relationship between the results of the wind tunnel test and the field measurement had to be determined. Accordingly, the set-up and testing method in the wind tunnel had to be modified from the field measurement to simulate the real behavior of a chimney under the wind flow with a larger Reynolds number. It enabled the results of the wind tunnel tests to be correlated with the field measurement. The model surface roughness and different turbulence intensity flows were added to the test. The simulated results of the wind tunnel test agreed with the full-scale measurements in the mean surface pressure distribution behavior.

A comparative study of along and cross-wind responses of a tall chimney with and without flexibility of soil

  • Gorski, Piotr;Chmielewski, Tadeusz
    • Wind and Structures
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    • v.11 no.2
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    • pp.121-135
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    • 2008
  • The paper is concerned with a comparative study of both the along and cross-wind responses of a tall industrial chimney with and without flexibility of soil. The along-wind response has been estimated by means of approaches presented in three Standards: the Polish, the ISO and the Eurocode and by random vibration approach which is outlined below. The cross-wind response has been estimated by means of the three models developed by Vickery and Basu, Ruscheweyh and Flaga and methods presented in Standards: the Polish, the ISO and the Eurocode (Approach 1 and 2). Computer programmes were developed to obtain estimates of responses of a six-flue, 250 m-tall chimney. The analytical results computed according to the methods presented in different standards and random vibration approaches have been compared. Some unexpected conclusions have been observed.

The Analytic Analysis of Suppressing Jet Flow at Guide Tube of Circular Irradiation Hole in HANARO (하나로 원형 조사공의 안내관 제트유동 억제에 대한 해석)

  • Park Y. C.;Wu S. I.
    • 한국전산유체공학회:학술대회논문집
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    • pp.214-219
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    • 2004
  • The HANARO, a multi-purpose research reactor of 30 MWth, open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. The HANARO is composed of inlet plenum, grid plate, core channel with flow tubes and chimney. The reactor core channel is located at about twelve m (12 m) depth of the reactor pool and cold by the upward flow that the coolant enters the lower inlet of the plenum, rises up through the grid plate and the core channel and exit through the outlet of chimney. A guide tube is extended from the reactor core to the top of the reactor chimney for easily un/loading a target under the reactor normal operation. But active coolant through the core can be Quickly raised up to the top of the chimney through the guide tube by jet flow. This paper is described an analytical analysis to study the flow behavior through the guide tube under reactor normal operation and unloading the target. As results, it was conformed through the analysis results that the flow rate, about fourteen kilogram per second (14 kg/s) suppressed the guide tube jet and met the design cooling flow rate in a circular flow tube, and that the fission moly target cooling flow rate met the minimum flow rate to cool the target.

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THE ANALYTIC ANALYSIS OF SUPPRESSING JET FLOW AT GUIDE TUBE OF CIRCULAR IRRADIATION HOLE IN HANARO (하나로 원형 조사공의 안내관 제트유동 억제에 대한 해석)

  • Park Y.C.;Wu S.I.
    • Journal of computational fluids engineering
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    • v.10 no.2
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    • pp.1-6
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    • 2005
  • The HANARO, a multi-purpose research reactor of 30 MWth, open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. The HANARO is composed af inlet plenum, grid plate, core channel with flow tubes and chimney. The reactor core channel is located at about twelve meters (12 m) depth of the reactor pool and cooled by the upward flow that the coolant enters the lower inlet of the plenum, rises up through the grid plate and the core channel and comes out from the outlet of chimney. A fission moly guide tube is extended from the reactor core to the top of the reactor chimney for easily loading a fission moly target under the reactor normal operation. But active coolant through the core can be quickly raised up to the top of the chimney through the guide tube by jet flow. This paper describes an analytical analysis that is the study of the flow behavior through the guide tube under reactor normal operation and unloading the target. As results, it was conformed through the analysis results that the flow rate, reduced to about fourteen kilogram per second (14 kg/s) from the original flow rate of sixteen point three kilogram per second (16.3 kg/s) did not show the guide tube jet.

Parametric Study on the Heat Loss of the Reactor Vessel in the Nuclear Power Plant (원자력 발전 원자로 용기의 열손실 설계인자에 관한 연구)

  • Jong-Ho Park;Seoug-Beom Kim
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.5
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    • pp.827-836
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    • 2004
  • The design parameter of the heat loss for the pressurized water reactor has been studied. The heat loss from the reactor vessel through the air gap. insulation are analysed by using the computational fluid dynamics code, FLUENT. Parametric study has been performed on the air gap width between the reactor vessel wall and the inner surface of the insulation, and on the insulation thickness. Also evaluated is the performance degradation due to the chimney effect due to gaps left between the panels during the installation of the insulation system. From the analysis results, the optimal with of air gap and insulation thickness and the value of heat loss are obtained The results show how the heat loss varies with the air gap width and insulation thickness. The temperature and the velocity distributions are also presented. From the results of the evaluation. the optimal air gap width and the optimal insulation thickness are obtained. As the difference between the predicted heat loss and measured heat loss from the reactor vessel is construed Primarily as losses due to chimney effect. the contribution of the chimney effect to the total heat loss is quantitatively indicated.

Numerical modelling for evaluating the TMD performance in an industrial chimney

  • Iban, A.L.;Brownjohn, J.M.W.;Belver, A.V.;Lopez-Reyes, P.M.;Koo, K.
    • Wind and Structures
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    • v.17 no.3
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    • pp.263-274
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    • 2013
  • A numerical technique for fluid-structure interaction, which is based on the finite element method (FEM) and computational fluid dynamics (CFD), was developed for application to an industrial chimney equipped with a pendulum tuned mass damper (TMD). In order to solve the structural problem, a one-dimensional beam model (Navier-Bernoulli) was considered and, for the dynamical problem, the standard second-order Newmark method was used. Navier-Stokes equations for incompressible flow are solved in several horizontal planes to determine the pressure in the boundary of the corresponding cross-section of the chimney. Forces per unit length were obtained by integrating the pressure and are introduced in the structure using standard FEM interpolation techniques. For the fluid problem, a fractional step scheme based on a second order pressure splitting has been used. In each fluid plane, the displacements have been taken into account considering an Arbitrary Lagrangian Eulerian approach. The stabilization of convection and diffusion terms is achieved by means of quasi-static orthogonal subscales. For each period of time, the fluid problem was solved and the geometry of the mesh of each fluid plane is updated according to the structure displacements. Using this technique, along-wind and across-wind effects have been properly explained. The method was applied to an industrial chimney in three scenarios (with or without TMD and for different damping values) and for two wind speeds, showing different responses.

Dynamic soil-structure interaction studies on 275m tall industrial chimney with openings

  • Jayalekshmi, B.R.;Thomas, Ansu;Shivashankar, R.
    • Earthquakes and Structures
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    • v.7 no.2
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    • pp.233-250
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    • 2014
  • In this paper, a three dimensional soil-structure interaction (SSI) is numerically simulated using finite element method in order to analyse the foundation moments in annular raft of tall slender chimney structures incorporating the effect of openings in the structure and the effect of soil flexibility, when the structure-soil system is subjected to El Centro (1940) ground motion in time domain. The transient dynamic analysis is carried out using LS-DYNA software. The linear ground response analysis program ProShake has been adopted for obtaining the ground level excitation for different soil conditions, given the rock level excitation. The radial and tangential bending moments of annular raft foundation obtained from this SSI analysis have been compared with those obtained from conventional method according to the Indian standard code of practice, IS 11089:1984. It is observed that tangential and radial moments increase with the increase in flexibility of soil. The analysis results show that the natural frequency of chimney decreases with increase in supporting soil flexibility. Structural responses increase when the openings in the structure are also considered. The purpose of this paper is to propose the need for an accurate evaluation of the soilstructure interaction forces which govern the structural response.

Performance of a Chimney Drain in Reinforced Earth Wall for Reduction of Pore Water Pressure During Rainfall - a Numerical Investigation (보강토 옹벽에 적용되는 연직 배수시스템의 강우시 수압 저감 효과 - 수치해석 연구)

  • Yoo, Chung-Sik;Kim, Sun-Bin;Jung, Hyuk-Sang
    • Journal of the Korean Geotechnical Society
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    • v.24 no.5
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    • pp.99-106
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    • 2008
  • This study is concernsed with the effect of a chimney drainage system installed at the back of reinforced soil block on preventing the pore water pressure development. A series of finite-element analyses based on transient seepage analysis were performed for a number of cases with different patterns of the chimney drainage system. The results were thoroughly analyzed to get insight into the mechanism of pore water pressure reduction effect of the chimney drainage system. It is shown that a vertical drainage system installed at the back of reinforced zone can be an effective means of maintaining the wall stability during rainfall by preventing pore pressure increase in the reinforced as well as the backfill zones. Also shown is that the optimum height of the chimney drain is 50% of the wall height. Practical implications of the findings were discussed.