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ISSN Imprimir: 1064-2285
ISSN On-line: 2162-6561
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EXPERIMENTAL VALIDATION OF PRANDTL NUMBER EXPONENT IN CORRELATION WITH NUSSELT NUMBER FOR DIFFERENT PLATE ORIENTATIONS OF THE SINGLE-PHASE FLOW PLATE HEAT EXCHANGER
RESUMO
This research is intended to validate the exponent of Prandtl number Pr used in the correlations of Nusselt number Nu for forced convective heat transfer in a plate heat exchanger at different chevron angles β for single-phase flow. The heat transfer characteristics of 10 wt.% and 30 wt.% ethylene glycol solutions in a plate heat exchanger are studied experimentally in two segments. In the first segment, the 30 wt.% ethylene glycol aqueous solution and water are used in cooling and heating loops, respectively. The heat transfer data is obtained for the 30 wt.% ethylene glycol with Reynolds number Re ranging from 100 to 800 and Pr from 12 to 28. In the second segment, the same experiment is repeated with a 10 wt.% ethylene glycol aqueous solution and heat transfer data is extracted with Re ranging from 120 to 800 and Pr from 6 to 11. Two symmetric (β = 30°/30° and 60°/60°) and one mixed (β = 30°/60°) chevron angle plates are used in both segments. The modified Wilson plot has been used for reduction of the heat transfer data. The Nu number has shown some increase with increase in Pr corresponding to the given Re and plate chevron angle β. The results prove that the Pr number exponent varies from 0.3 to 0.4 for plate-type heat exchangers for different conditions, and Nu shows more variation with change in Re and less with change in Pr.