HIGH EFFICIENCY HEAT TRANSFER TUBE FOR HEAT EXCHANGER

摘要

A high-performance heat transfer tube for an evaporator of an air conditioning or refrigeration system is formed on a grooved mandrel that has a sufficient number of grooves, such as 60 to 90 for a 5/8 inch tube, to produce a small-pitch internal rib enhancement. The small pitch ensures that the spaces or grooves between ribs are about two to five times the characteristic film thickness of the refrigerant liquid on the inside of the tube. This construction permits use of a thinner tube wall starting blank without loss of strength. Lands or unworked portions can be left at the tube ends to facilitate flaring into a tube sheet.