Experimental analysis of natural convection within a thermosyphon

Technical Report · Wed Sep 01 04:00:00 EDT 1993

DOI:https://doi.org/10.2172/10188066· OSTI ID:10188066

Clarksean, R

The heat transfer characteristics of a thermosyphon designed to passively cool cylindrical heat sources are experimentally studied. The analysis is based on recognizing the physics of the flow within different regions of the thermosyphon to develop empirical heat transfer correlations. The basic system consists of three concentric cylinders, with an outer channel between the outer two cylinders, and an inner channel between the inner two cylinders. Tests were conducted. with two different process material container diameters, representing the inner cylinder, and several different power levels. The experimentally determined local and average Nu numbers for the inner channel are in good agreement with previous work for natural convection between vertical parallel plates, one uniformly heated and the other thermally insulated. The implication is that the heat transfer off of each surface is independent of the adjacent surface for sufficiently high Ra numbers. The heat transfer is independent because of limited interaction between the boundary layers at sufficiently high Ra numbers. As a result of the limited interaction, the maximum temperature within the system remained constant, or decreased slightly when the radii of the inner cylinders increased for the same amount of heat removal.

• Research Organization: Argonne National Lab., Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 10188066
• Report Number(s): ANL/FC/CP--76325; CONF-931087--2; ON: DE93041174
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400
DATA ANALYSIS
EXPERIMENTAL DATA
FLOW RATE
HEAT TRANSFER AND FLUID FLOW
MASS TRANSFER
NATURAL CONVECTION
NUSSELT NUMBER
TESTING
THERMOSYPHON EFFECT
THERMOSYPHONS