Heat transfer tube with grooved inner surface

A tube comprising an inner surface and a longitudinal axis, wherein the inner surface comprises:

• a. a plurality of primary fins, wherein at least some of the plurality of primary fins are oriented substantially parallel to each other and wherein at least some of the plurality of primary fins are oriented at an angle relative to the longitudinal axis wherein the plurality of primary fins is divided into a first portion of primary fins and a second portion of primary fins;
• b. a plurality of grooves defined by adjacent primary fins;
• c. a plurality of intermediate fins, wherein the plurality of intermediate fins are positioned in at least some of the plurality of grooves and wherein at least some of the intermediate fins are oriented at an angle relative to at least some of the primary fins;
• and
• d. a trenched groove that runs between the first portion of primary fins and the second portion of primary fins.

A heat transfer tube comprising an inner surface and an outer surface, wherein the inner surface comprises:

• a. two sets of fins, comprising (i) a plurality of adjacent primary fins defining a groove between adjacent primary fins;
• and (ii) a plurality of short, intermediate fins positioned in at least some of the grooves between the adjacent primary fins, wherein the plurality of short intermediate fins are provided in a number greater than the number of adjacent primary fins;
• and
• b. a channel dividing the two set of fins providing a trench for fluid heat transfer mediums to flow between the two sets of fins.

A tube comprising an inner surface and an outer surface, wherein the inner surface comprises:

• a. a first set of a plurality of primary fins positioned substantially parallel to one another and defining (i) a plurality of primary fin axes and (ii) a first set of grooves between each set of adjacent primary fins;
• b. a first set of a plurality of intermediate fins provided in an amount greater than the amount of the first set of primary fins, wherein the first set of a plurality of intermediate fins is positioned substantially parallel to one another in at least some of the first set of grooves,
• c. a second set of a plurality of primary fins positioned substantially parallel to one another and spaced apart from the first set of primary fins by a channel, wherein the second set of a plurality of primary fins define (i) a plurality of primary fin axes and (ii) a second set of grooves between each set of adjacent primary fins;
• d. a second set of a plurality of intermediate fins provided in an amount greater than the amount of the second set of primary fins, wherein the second set of a plurality of intermediate fins is positioned substantially parallel to one another in at least some of the second set of grooves, and
• e. a channel that separates the first set of primary and intermediate fins from the second set of primary and intermediate fins.