Finned helicoidal heat exchanger

Abstract

Heat exchanger having a plurality of heat transfer tubes arranged substantially in the shape of a helicoidal tube with the individual coils running parallel to one another, and a plurality of fins secured to the external surfaces of the heat transfer tubes and arranged perpendicular to the tube to extend outwardly therefrom. The first working fluid flows inside the heat transfer tubes, and air flows through a passage defined between the adjacent fins and at right angles to the axis of each heat transfer tube. The blower is placed co-axial with the helicoid's axis to further enhance the heat exchange.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of United States Patent Application No. 10 / 748,636 filed on Dec. 30, 2003.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH [0002] Not Applicable. APPENDIX [0003] Not Applicable. BACKGROUND OF THE INVENTION [0004] 1. Field of The Invention [0005] The present invention relates generally to the field of heat exchangers and, more particularly, to a heat exchanger having helical coils whose performance is improved by the addition of fins. [0006] 2. Related Art [0007] Heat exchangers are used to transfer heat between fluids. Many different designs accomplish this, invariably by relying on the basic thermodynamic principle that heat is transferred from a warmer body to a cooler one. One of the more commonly used types of heat exchangers is a fin and tube heat exchanger, such as the evaporator or condenser of a common air conditioner. Separate fin strips are arranged in an array with holes in each to receive per...

AI Technical Summary

Benefits of technology

[0011] It is in view of the above problems that the present invention was developed. The invention is a heat exchanger having a plurality of heat transfer tubes arranged substantially in the shape of a helicoidal tube with the individual coils running parallel to one another in a spiral pattern. A plurality of fins are secured to the external surfaces of the heat transfer tubes and extend away therefrom. The first working fluid flows inside the heat transfer tubes, and the second working fluid, typically air, flows through the passages between the adjacent fins and tubes. To further enhance the exchange of thermal energy between the fluids, a blower may be placed inside the coil cavity or around the coil, with blower's blades being parallel to the central coil axis.

[0012] The invention incorporates characteristics of high fin density, close coil spacing, and non-uniform fin size. The attachment of the fins to at least two adjacent loops not only enhances the rate of heat transfer, but also provides for enhanced structural strength that allows the use of this design for applications where the first heat exchanging fluid is at elevated pressures. These characteristics and the absence of 180 degree bends result in a significantly more compact heat exchanger having superior heat transfer characteristics.

Problems solved by technology

The return bends force the first fluid to turn 180 degrees in each pass thereby causing an excessive pressure drop in the first fluid.

This non-uniform air velocity through different portions of the coil often creates a variety of operational problems and inefficiencies in which the coil is incorporated, leading to a lowering the overall heat exchange capability of the coil.

They also limit the types of fin material that can be used.

High pressure applications also are problematic because in known heat exchangers the fins do not strengthen the heat exchanger and, thus, service life is adversely affected.

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