Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

CFD SIMULATION OF SOLAR RECEIVER JET IMPINGEMENT HEAT TRANSFER: RANS VS LES

Get access (open in a dialog) DOI: 10.1615/IHTC16.cms.023262
pages 1971-1978

Abstrakt

Jet impingement heat transfer is well known to enhance local heat transfer because of the local increase in the heat transfer coefficient or Nusselt number. Away from the Nusselt number peak close to the stagnation point, there is a second peak in the Nusselt number as the flow transitions from laminar to turbulent. Traditional two-equation turbulence models like the SST k-ω in Reynolds-Averaged Navier-Stokes (RANS) Computational Fluid Dynamics (CFD) is shown to be unable to accurately capture the double-hump phenomenon on the Nusselt number distribution for a flat impingement surface. The Transition SST four-equation model does however correlate well with the experimental results from literature and initial Large Eddy Simulation (LES) results. A case study is presented of the impingement heat transfer in a solar tower cavity receiver. The absorbing surface of the receiver is comprised of an array of pointed 'pyramid' objects chosen for their low outward radiation view factor. Internal to these objects are flow paths that utilize jet impingement heat transfer for efficient transfer of heat to the heat transfer fluid. A solar heat source distribution on the receiver's absorbing surface is produced by a ray-tracing simulation of a selected heliostat field using SolTrace. This heat source is applied in the conjugate heat transfer ANSYS Fluent CFD model using the Transition SST turbulence model that contains the Heat Transfer Fluid (HTF) flow paths. Through this simulation, the thermal efficiency of the receiver as well as temperature distributions in the fluid and solid components can be evaluated.