You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
<spanclass="p">}</span></code></pre></figure></div></div></div></li></ol><h2class="bibliography">2020</h2><olclass="bibliography"><li><divclass="row"><divclass="col-sm-2 abbr"><abbrclass="badge">Master’s Thesis</abbr></div><divid="rubini_masters" class="col-sm-8"><divclass="title">A Novel Turbomachine for Hydrocarbon Cracking: An Aerothermal Investigation</div><divclass="author"> Dylan Rubini </div><divclass="periodical"><em>Master’s Thesis, University of Oxford</em> , May 2020 </div><divclass="periodical"></div><divclass="links"><aclass="abstract btn btn-sm z-depth-0" role="button">Abs</a><aclass="bibtex btn btn-sm z-depth-0" role="button">Bib</a><ahref="http://dx.doi.org/10.13140/RG.2.2.24319.93609" class="btn btn-sm z-depth-0" role="button" rel="external nofollow noopener" target="_blank">HTML</a></div><divclass="abstract hidden"><p>This work presents an aerothermal investigation of a novel turbomachine used for light olefin production. The turbomachine – the Roto-Dynamic Reactor (RDR) – replaces the radiant section of a conventional steam cracking plant. The design objectives are to efficiently transfer shaft work (provided by an electric motor) to the working fluid whilst minimising the residence time, hydrocarbon partial pressure, coking and secondary reactions, and increasing the olefin yield and process temperature. The novel reactor is comprised of a 1.5 stage turbomachine with the outlet of one stage connected to the inlet of the next through a toroidal-shaped vaneless diffuser space. This yields a regenerative design. The concept is investigated using the in-house CFD code TBLOCK using a combination of Reynolds-averaged Navier-Stokes (RANS) and large eddy simulation (LES) strategies. Numerical investigations show a steady rise in temperature across the reactor with a higher outlet temperature (T = 1350 K) than typical conventional pyrolytic reactors. The pilot design shows a low residence time of 53 ms for an average particle and significantly higher viscous shear stresses than conventional furnaces. These two factors solidify the economic feasibility of the concept. This work validates the regenerative nature of the design, with the flow progressing as nearly independent streamtubes. Numerical results confirm the design requirement of a temporally and circumferentially uniform inlet field at the inlet of each regenerative pass of the reactor. Secondary and tip leakage flow mechanisms are explored to determine the impact on work added to the working fluid. The high-turning impulsive blading results in very large losses in work coefficient. Shock systems are probed in detail to understand the process of energy transformation into internal energy, in addition to the shockwave/boundary layer interaction that promotes strong mixing. This internal mixing within a regenerative pass is required to enable a regenerative design and prevent secondary reactions. The current design exhibits sufficient internal mixing to decrease the static pressure, but also to drive chemical reaction and crack long-chain hydrocarbons into shorter molecular structures. This work introduces guidewalls to mitigate lateral mixing between adjacent regenerative passes and improve the guiding of the flow in the vaneless diffuser space.</p></div><divclass="bibtex hidden"><figureclass="highlight"><pre><codeclass="language-bibtex" data-lang="bibtex"><spanclass="nc">@phdthesis</span><spanclass="p">{</span><spanclass="nl">rubini_masters</span><spanclass="p">,</span>
<spanclass="na">publisher</span><spanclass="p">=</span><spanclass="s">{Master's Thesis, University of Oxford}</span><spanclass="p">,</span>
97
+
<spanclass="na">school</span><spanclass="p">=</span><spanclass="s">{Master's Thesis, University of Oxford}</span><spanclass="p">,</span>
98
+
<spanclass="na">title</span><spanclass="p">=</span><spanclass="s">{A Novel Turbomachine for Hydrocarbon Cracking: An Aerothermal Investigation}</span><spanclass="p">,</span>
0 commit comments