Influence of surface roughness on a spray cooling system with R134a. Part I: Heat transfer measurements
2013 (English)In: Experimental Thermal and Fluid Science, ISSN 0894-1777, Vol. 46, 183-190 p.Article in journal (Refereed) Published
Experimental measurements in a spray cooling test rig were carried out for two different heater surface roughnesses and for two different types of nozzles with the dielectric refrigerant R134a. In this paper, results of the heat transfer measurements are presented. The analysis of the results explains the influence of the volumetric flow rate, the surface roughness and the type of nozzle (through the spray parameters) on the spray cooling boiling curve, on the Nusselt number and on the efficiency. It has been found that the effect of a smooth roughness is to delay the onset of the nucleate boiling, but once this regime has started, boiling is so fast that the CHF (Critical Heat Flux) is reached at lower heater temperatures and lower heat fluxes. In a companion paper the sprayed refrigerant film thickness measurements and its relation with the heat transfer measurements are presented.
Place, publisher, year, edition, pages
2013. Vol. 46, 183-190 p.
Boiling curve, Experimental measurements, Heat transfer measurements, Heater temperatures, Spray cooling, Spray parameters, Test rigs, Volumetric flow rate
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-120276DOI: 10.1016/j.expthermflusci.2012.12.010ISI: 000315975600020ScopusID: 2-s2.0-84873566092OAI: oai:DiVA.org:kth-120276DiVA: diva2:614873
QC 201304082013-04-082013-04-042013-04-08Bibliographically approved