Low temperature heat transfer in a plate-fin type heat exchanger

Abstract

Considerable amounts ofcopper and its alloys are employed in the manufacture of heat exchangers for low tempera ture refr igerat ion equipment. In recent yea r s , c h r o m e nickel steels are being used for this purpose. From the standpoint of compactness , minimum metal volume, low hydraul ic res is tance , and small loss of the cooling effect to the surroundings, plate-fin type heat exchangers descr ibed below offer considerable promise . In the following, the heat t r ans fe r cha rac te r i s t i c s of these heat exchangers wi!l be discussed. The welding of the fins with the p r imary heat t r ans f e r sur faces (plates) in these leads to a large increase in the total surface. Compared to the conventional shel l -and-tube type exchangers the s u r face of a plate-f in type exchanger is nine t imes g rea te r on a unit volume basis . Depending on the number and thickr, ess of the fins in each cavity, and also on the configuration of and the distance between the individual cavities, it ranges f rom 900 to 1800 m 2 / m 3. As a f ract ion of the secondary surface (fins) this comes to 0.50-0.90.