Finned tube heat exchanger

Abstract

A heat exchanger comprises a tube and fins extending from an outer surface of the tube. The fins comprise first and second sets of fins with the first set of fins oriented in a first direction with respect to an axial direction of the tube and the second set of fins oriented in a second direction with respect to the axial direction of the tube to expose at least a portion of the first and second sets of fins to a free stream.

Description

BACKGROUND[0001]The invention relates generally to heat exchangers and, more particularly, to a finned tube heat exchanger.[0002]A finned tube heat exchanger includes a tube and fins disposed on the outer surface of the tube. Several designs for the fins are known in the art, including a serrated fin configuration. A serrated fin configuration can be formed on a tube by creating serrations in a sheet of metal and then winding the serrated sheet around the tube.[0003]Fins including serrations, slits, and bending aspects are known in the art. Kimura (EP 0854344 A2) discloses a heat exchanger having finned tubes. The finned tubes are fabricated by attaching fins having the shape of a circular plate to the outer surface of the tube. Each fin is provided with bent portions that are formed by forming radial slits in a peripheral portion of the fin to divide the peripheral portion into a plurality of segments and then bending each segment in an axial direction of the tube along a bending l...

AI Technical Summary

Benefits of technology

"The patent describes different heat exchanger designs that improve the efficiency of heat transfer. These designs include fins that are oriented in different directions or arranged in a helical path to maximize the surface area in contact with the free stream. These designs also include serrated sections and solid sections that are arranged in a specific way to enhance the heat transfer process. Overall, these designs improve the heat exchanger's ability to transfer heat more effectively, leading to better performance and efficiency."

Problems solved by technology

Therefore, the bent portions affect the flow and prevent or lessen the flow separation, but do not act as prime heat transfer surfaces.

As a result, the heat transfer capability is compromised.

However, increased flow mixing also leads to increased pressure losses.

This twisting and inclination may increase heat transfer due to increased mixing, but the effect may become detrimental after some point.

There may be increased pressure losses since the flow will most likely separate.

However, serrated fins generate increased pressure drops compared to a simple solid fin and have less material and area for heat transfer.

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