Calculation of radiation heat transfer view factors among fuel rod bundles based on CFD method.pdfVIP

Annals of Nuclear Energy 71 (2014) 462–466 Contents lists available at ScienceDirect Annals of Nuclear Energy journal homepage: /locate/anucene Technical Note Calculation of radiation heat transfer view factors among fuel rod bundles based on CFD method Lei Yang a, Wenzhen Chen a,b,?, Lei Luo a, Xinwen Zhao a a Department of Nuclear Energy Science and Engineering, Naval University of Engineering, Wuhan 430033, China b Institute of Thermal Science and Power Engineering, Naval University of Engineering, Wuhan 430033, China article info Article history: Received 13 February 2014 Received in revised form 18 April 2014 Accepted 19 April 2014 Available online 16 May 2014 Keywords: Radiation heat transfer View factor Rod bundle assembly Homotopy CFD abstract The view factor has a great in?uence on the radiation heat transfer. Existing theoretical formulas about the view factors among fuel rod bundles are only suitable for the square assemblies. For non-standard bundle assembly structure, such as the circular and hexagonal bundle assemblies, the view factors cannot be calculated by the theoretical formulas. Aiming at the problem, two different radiation heat transfer models, which are discrete transfer model (DTRM) and discrete ordinates model (DO), are proposed based on the CFD method and validated by the theoretical formulas under the condition of square assembly. The results show that the DTRM can accurately and reliably calculate the view factor among the rods in square bundle. Taking into account the similarity in the radiation heat transfer among the rods in homotopy bundle assembly structures, the DTRM model can be used for the calculation of view factor in other non-standard fuel rod bundle assembly. ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction During the normal operation of the reactor, the heat transfer in the core is dominated by the convective heat transfer and thermal conduction. While the severe accident takes place in the reactor, the core will b