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Title: Experimental research on heat transfer of natural convection in vertical rectangular channels with large aspect ratio

This work presents the experimental research on the steady laminar natural convection heat transfer of air in three vertical thin rectangular channels with different gap clearance. The much higher ratio of width to gap clearance (60-24) and the ratio of length to gap clearance (800-320) make the rectangular channels similar with the coolant flow passage in plate type fuel reactors. The vertical rectangular channels were composed of two stainless steal plates and were heated by electrical heating rods. The wall temperatures were detected with the K-type thermocouples which were inserted into the blind holes drilled in the steal plates. Also the air temperatures at the inlet and outlet of the channel were detected. The wall heat fluxes added to the air flow were calculated by the Fourier heat conduction law. The heat transfer characteristics were analyzed, and the average Nusselt numbers in all the three channels could be well correlated with the Rayleigh number or the modified Rayleigh number in a uniform correlation. Furthermore, the maximum wall temperatures were investigated, which is a key parameter for the fuel's integrity during some accidents. It was found that even the wall heat flux was up to 1500 W/m{sup 2}, the maximum wallmore » temperature was lower than 350 C. All this work is valuable for the plate type reactor's design and safety analysis. (author)« less
Authors:
; ;  [1] ;  [2] ; ;  [3]
  1. State Key Laboratory of Multi Phase Flow in Power Engineering, Xi'an JIaotong University, Xi'an, Shaanxi 710049 (China)
  2. (China)
  3. School of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)
Publication Date:
OSTI Identifier:
21248834
Resource Type:
Journal Article
Resource Relation:
Journal Name: Experimental Thermal and Fluid Science; Journal Volume: 34; Journal Issue: 1; Other Information: Elsevier Ltd. All rights reserved
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; 22 GENERAL STUDIES OF NUCLEAR REACTORS; NATURAL CONVECTION; THERMAL CONDUCTION; ASPECT RATIO; RAYLEIGH NUMBER; WALLS; PLATES; AIR FLOW; HEAT FLUX; REACTORS; NUSSELT NUMBER; FUEL INTEGRITY; SAFETY ANALYSIS; COOLANTS; CORRELATIONS; DESIGN; HEATING; LAMINAR FLOW; STEADY FLOW Rectangular channels