Development of innovative plate heat exchangers for refrigeration applications

This paper presents the experimental work carried out to apply the enhanced surfaces widely used for intube refrigerant condensation and vaporisation, such as micro-fin and cross-grooved, into plate heat exchangers (PHE). The paper investigates also the effect of an increase in the surface roughness of the plate on the heat transfer performance in refrigerant vaporisation. The enhanced surfaces are experimentally evaluated both in vaporisation and condensation tests and compared against a traditional PHE surface. The experimental facility and the test procedures are fully described. The experimental results show that the increase in surface roughness is useful only in vaporisation, whereas the cross-grooved surface is useful both in vaporisation and condensation. The cross-grooved surface gives an increase in the heat transfer performance from 40% in vaporisation to 50% in condensation with respect to a traditional PHE surface