Laser treated metal heat exchangers for boiling heat transfer enhancement

Abstract

Laser treatment of metallic layers can significantly change the morphology of the surface. Due to the action of the laser beam, the surface roughness considerably increases. Moreover, laser can modify the shape of the samples to produce the extended surface of longitudal fins. The paper discusses the development of such metal heat exchangers as well as the effects of laser beam treatment on the surface characteristics. The test results of surface morphology were presented and discussed. The samples produced in the course of the experiments were used to test their performance for boiling heat transfer of two working agents (distilled water and ethyl alcohol under ambient pressure). The test results indicated a significant improvement in heat flux in relation to the unmodified surface (without laser treatment). The laser treatment method proved to provide considerable advantage over the unmodified surface.