US Patent 9243851 Heat exchange tube and method of using the same

A heat exchanger tube includes protrusions extending into the internal volume to turbulate a fluid flow for improved heat transfer. The protrusions are arranged to provide dimpled and un-dimpled regions in order to provide increased heat transfer together with decreased pressure drop. A method of transferring heat by flowing a fluid into a tube, turbulating the fluid in a dimpled first tube section, developing a thermal boundary layer in an un-dimpled second section, and turbulating the fluid in a dimpled second tube section is also presented.