Cross elliptic-section heat exchange pipe

The cross elliptic-section heat exchange pipe consists of several pipe sections with cross axis elliptic section, two sections with circular section at two end and their transitional sections. The features of heat exchange pipe are that two adjacent sections of elliptic section have major axis lines crossed in certain angle, preferably 90 deg and 60 deg. It has the advantages of obvious reinforced heat exchange between the inside and the outside the the pipe, small flow resistance and simple forming process. Compared with common heat exchange pipe with smooth circular section, it has a 2-3 times higher heat transfer coefficient to laminar flow and a 30 % higher heat transfer coefficient to turbulent flow.