Effect of surface geometry in steam absorption into a falling film of aqueous solution of LiBr

Journal Article · Fri Mar 01 04:00:00 EST 1996 · Heat Transfer - Japanese Research

OSTI ID:276282

Kiyota, Masanori; Morioka, Itsuki; Ousaka, Akiharu ^[1]

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1. Tokushima Univ. (Japan). Dept. of Mechanical Engineering

Absorption chillers are becoming attractive since they do not use Freon gases which destroy the ozone layer and can be driven by heat. Improvement of the absorber is necessary to make absorption chillers compact. In this paper, heat-transfer surfaces which show maximum absorption performance are sought. Grooved pipes are known to be effective for promoting gas absorption into falling water. They are tested for water vapor absorption with four different groove depths as well as two different knurled surfaces. The pipe with the deepest groove shows enhancement of about 1.5--1.9 in the Reynolds number range of 200--500. The knurled surfaces are not effective for absorption, but they have better wettability at a lower flow rate and furthermore for higher knurl height, absorption increases at larger flow rates. Film thickness is measured by the contact probe method. The average film thickness curve has large undulation for deeper grooves but it is flat for the shallow grooves.

• OSTI ID: 276282
• Journal Information: Heat Transfer - Japanese Research, Journal Name: Heat Transfer - Japanese Research Journal Issue: 1 Vol. 24; ISSN HTJPAU; ISSN 0096-0802
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
ABSORPTION
ABSORPTION REFRIGERATION CYCLE
AUGMENTATION
FILM FLOW
HEAT TRANSFER
LITHIUM BROMIDES
MASS TRANSFER
REFRIGERATING MACHINERY
STEAM
WORKING FLUIDS