Comparison of boiling heat transfer on heaters with mesh structure and microfins

Abstract

Abstract The topic of heat transfer efficiency during boiling is considerably important and more attention is paid to the improvement of heat flux using various microstructures. The article focuses on the comparison of boiling heat transfer between exchangers with a porous mesh structure and microfins. The tests were performed on the brass mesh of the wire diameter of 0.25 mm as well as on the microfin surface of the width 1 mm. The height of both the samples was the same and equalled to 0.5 mm. The boiling liquids were distilled water and ethyl alcohol. The experiments were conduced under ambient pressure. The results of the tests carried out confirm that these coatings have a positive effect on the heat transfer. The basis of this analysis is the course of processes taking place on individual samples and the influence on the heat flux values. The comparison of the experimental results and correlations has proven differences between them – especially in the case of pinfin surface (for both the boiling agents). The differences varied with changing the heat flux.