Distribution of air-water mixtures in parallel vertical channels as an effect of the header geometry
- Diptem, University of Genova, Via all'Opera Pia 15a, 16145 Genova (Italy)
Uneven phase distribution in heat exchangers is a cause of severe reductions in thermal performances of refrigeration equipment. To date, no general design rules are available to avoid phase separation in manifolds with several outlet channels, and even predicting the phase and mass distribution in parallel channels is a demanding task. In the present paper, measurements of two-phase air-water distributions are reported with reference to a horizontal header supplying 16 vertical upward channels. The effects of the operating conditions, the header geometry and the inlet port nozzle were investigated in the ranges of liquid and gas superficial velocities of 0.2-1.2 and 1.5-16.5 m/s, respectively. Among the fitting devices used, the insertion of a co-axial, multi-hole distributor inside the header confirmed the possibility of greatly improving the liquid and gas flow distribution by the proper selection of position, diameter and number of the flow openings between the supplying distributor and the system of parallel channels connected to the header. (author)
- OSTI ID:
- 21195816
- Journal Information:
- Experimental Thermal and Fluid Science, Vol. 33, Issue 5; Other Information: Elsevier Ltd. All rights reserved; ISSN 0894-1777
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
MASS DISTRIBUTION
AIR
CONFIGURATION
MIXTURES
WATER
HEAT EXCHANGERS
GAS FLOW
REFRIGERATING MACHINERY
DESIGN
LIQUID FLOW
OPENINGS
PERFORMANCE
PLATES
VELOCITY
THERMAL EFFICIENCY
TWO-PHASE FLOW
Flow distribution
Air-water mixture
Parallel channels
Plate heat exchangers
Flute fitting