Effects of heat exchanger tube parameters on nucleate pool boiling heat transfer in a scaled IRWST

Book · Thu Aug 01 04:00:00 EDT 1996

OSTI ID:271922

Chun, M H; Kang, M G ^[1]

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1. Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Dept. of Nuclear Engineering

In an effort to determine the combined effects of major parameters of heat exchanger tubes on the nucleate pool boiling heat transfer in the scaled in-containment refueling water storage tank (IRWST), a total of 1,966 data for q{double_prime} versus {Delta}T has been obtained using various combinations of tube diameters, surface roughness, and tube orientations. The experimental results show that (1) increased surface roughness enhances heat transfer for both horizontal and vertical tubes, (2) the two heat transfer mechanisms, i.e., enhanced heat transfer due to liquid agitation by bubbles generated and reduced heat transfer by the formation of large vapor slugs and bubble coalescence are different in two regions of low heat fluxes (q{double_prime} {le} 50 kW/m{sup 2}) and high heat fluxes (q{double_prime} > 50 kW/m{sup 2}) depending on the orientation of tubes and the degree of surface roughness, and (3) the heat transfer rate decreases as the tube diameter is increased for both horizontal and vertical tubes, but the effect of tube diameter on the nucleate pool boiling heat transfer for vertical tubes is greater than that for horizontal tubes. Two empirical heat transfer correlations for q{double_prime}, one for horizontal tubes and the other for vertical tubes, are obtained in terms of surface roughness ({var_epsilon}) and tube diameter (D). In addition, a simple empirical correlation for nucleate pool boiling heat transfer coefficient (h{sub b}) is obtained as a function of heat flux (q{double_prime}) only.

• OSTI ID: 271922
• Report Number(s): CONF-960306--; ISBN 0-7918-1226-X
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
22 GENERAL STUDIES OF NUCLEAR REACTORS
AFTER-HEAT REMOVAL
DESIGN
ENGINEERED SAFETY SYSTEMS
EXPERIMENTAL DATA
HEAT EXCHANGERS
HEAT TRANSFER
NATURAL CONVECTION
NUCLEATE BOILING
PARAMETRIC ANALYSIS
POOL BOILING
REACTOR ACCIDENTS
REACTOR COOLING SYSTEMS
RHR SYSTEMS
TANKS
WATER COOLED REACTORS