magistrsko delo magistrskega študijskega programa II. stopnje Strojništvo
Luka Selan (Author), Božidar Šarler (Mentor), Boštjan Končar (Co-mentor)

Abstract

V magisteriju smo opravili toplotno analizo prototipa diverterskega elementa za stelarator W7-X, ki je sestavljen iz nosilne strukture, toplotnega ščita, medsloja in hladilnega kanala z vodo. Analizirali smo temperaturno porazdelitev elementa pri predvidenih pogojih obratovanja. Analizo smo numerično izvedli na podlagi metode kontrolnih volumnov s programskim paketom za računalniško dinamiko tekočin ANSYS CFX. Za verifikacijo modela diverterske enote smo opravili analizo občutljivosti računske mreže. Za validacijo izbranega modela vrenja smo primerjali rezultate simulacije z dostopnimi eksperimentalnimi podatki. Simulacije so obsegale različne materiale ščita, toplotne obremenitve ter tudi z vključitvijo spiralnega vložka v hladilni kanal. V modelu smo najprej privzeli model enofaznega turbulentnega toka vode v hladilnem kanalu na podlagi modela SST, kjer smo reševali sklopljen prenos toplote za trdnino in tekočino. Na podlagi parametrične študije smo ugotovili, da temperature materialov komponent v nobenem od analiziranih primerov ne dosežejo kritičnih vrednosti. Na posameznih mestih lahko temperatura stene hladilnega kanala presega temperaturo vrelišča vode. Zato smo opravili tudi dvofazno simulacijo toka z vključenim modelom vrenja. Rezultati kažejo, da je količina pare, ki nastane zaradi vrenja pri obratovalnih pogojih zanemarljiva, in zato ne predstavlja nevarnosti za prehod v filmsko vrenje.

Keywords

magistrske naloge;stelarator Wendelstein 7-X;računalniška dinamika tekočin;diverterska enota;podhlajeno vrenje;ANSYS CFX;dvofazni tok;termična analiza;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FS - Faculty of Mechanical Engineering
Publisher: [L. Selan]
UDC: 004.942:519.876.5:532(043.2)
COBISS: 120777475 Link will open in a new window
Views: 305
Downloads: 92
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Other data

Secondary language: English
Secondary title: Numerical simulation of single-phase and two-phase flow in the divertor unit of the stellarator Wendelstein 7-X
Secondary abstract: In this thesis we conducted thermal analysis of the prototype divertor element for W7-X stellarator, composed of the supporting structure, heat shield, interlayer and a cooling channel with water. We have analysed the temperature distribution at anticipated operating conditions. Based on the finite volume method, we performed the numerical analysis with the ANSYS CFX software. To verify the model of the diverter unit, we performed a sensitivity analysis of the computational mesh. We compared the simulation results with available experimental data to validate the selected boiling model. The simulations included different shielding materials, thermal loads and inclusion of a spiral insert in the cooling channel. In the model, we first adopted the model of a single-phase turbulent flow of water in the cooling channel based on the SST model, where we solved the coupled heat transfer for the solid and the liquid. Based on the parametric study, we found that the temperatures of the component materials do not reach critical values. At individual places, the temperature of the cooling channel wall can exceed the boiling temperature of water. Therefore, we also performed a two-phase flow simulation with the included boiling model. Results show that the amount of vapour generated by boiling is negligible and therefore does not pose a danger of transitioning into a film boiling.
Secondary keywords: master thesis;stellarator Wendelstein 7-X;computational fluid dynamics;divertor unit;subcooled boiling;two phase flow;
Type (COBISS): Master's thesis/paper
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. Ljubljana, Fak. za strojništvo
Pages: XXII, 54 str.
ID: 16382134