Heat exchanger

Patent metadata

Field	Value
Publication number	US-9891008-B2
Application number	US-44903308-A
Country	US
Kind code	B2
Filing date	Jan 22, 2008
Priority date	Jan 25, 2007
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

Each fin 30 is designed to have continuous lines of wave crests 34 and continuous lines of wave troughs 36 arranged at a preset angle in a specific angle range of 10 degrees to 60 degrees relative to the main stream of the air flow and symmetrically folded back about folding lines of a preset folding interval W along the main stream of the air flow. A ratio (a/p) of an amplitude ‘a’ of a waveform including one wave crest 34 and one adjacent wave trough 36 to a fin pitch ‘p’ satisfies a relation of 1.3×Re −0.5 <a/p<0.2. A ratio (W/z) of the folding interval W to a wavelength ‘z’ of the waveform satisfies a relation of 0.25<W/z<2.0. A ratio (r/z) of a radius of curvature ‘r’ at a top of the wave crest 34 or at a bottom of the wave trough 36 to the wavelength ‘z’ of the waveform satisfies a relation of 0.25<r/z. The continuous lines of the wave crests 34 and the continuous lines of the wave troughs 36 are arranged to have an angle of inclination a of not less than 25 degrees at a cross section of the waveform. This arrangement effectively improves the heat transfer coefficient of a heat exchanger and thereby allows effective size reduction of the heat exchanger.

First claim

The invention claimed is:

1. A heat exchanger configured to perform heat exchange by making a fluid flow between at least two opposed heat transfer members,
wherein each of the at least two opposed heat transfer members is structured to have a heat transfer plane to make the fluid flow thereon and equipped with wave crests and wave troughs formed on a predominant part of a surface of the heat transfer plane,
the wave crests and the wave troughs having multiple continuous lines, and
the multiple continuous lines of the wave crests and the multiple continuous lines of the wave troughs are alternately formed on the predominant part of the surface of the heat transfer plane,
the wave crests and the wave troughs are formed by a curved surface,
the wave crests and the wave troughs are arranged so that the multiple continuous lines of the wave crests and the multiple continuous lines of the wave troughs are formed in a V shape or multiple connected V shapes, wherein a pitch of wave of the wave crests and wave troughs in a direction perpendicular to a main stream of the fluid flow is non-constant, and wherein an apex of the V shape faces with the direction of the main stream of the fluid flow, with arms of the V shape extending in a direction opposite to the main stream of the fluid flow, with respect to the apex of the V shape,
the wave crests and the wave troughs are arranged so that the main stream of the fluid flow is perpendicular to the multiple continuous lines of the wave crests and the multiple continuous lines of the wave troughs that are found in the V shape and so right and left diagonal lines of the V shape intersect with the main stream of the fluid flow in a specific angle range of 10 degrees to 60 degrees, and thereby secondary flow, different from the main stream of the fluid flow, that flows along the surface of the wave crests and the wave troughs is generated on the surface of the heat transfer plane,
to generate the secondary flow effectively, the wave crests and the wave troughs being arranged to satisfy Inequality (1) given below:
1.3×Re −0.5 <a/p< 0.2  (1)

where ‘a’ denote an amplitude of a waveform including one wave crest and one wave trough, ‘p’ denotes a pitch as an interval between adjacent heat transfer planes of the at least two opposed heat transfer members, and ‘Re’ denotes a Reynolds number defined by a bulk flow rate and the pitch ‘p’,

each of the at least two opposed heat transfer members is structured to have the wave crest and the wave trough arranged to satisfy Inequality (2) given below:
0.25< W/z< 2.0  (2)

where ‘W’ denotes a folding interval of the V shape and ‘z’ denotes a wavelength of the waveform including the wave crest and the wave trough, and

each of the at least two opposed heat transfer members are structured to have the wave crest and the wave trough arranged to satisfy Inequality (3) given below:
0.25< r/z   (3)

wherein ‘r’ denotes a radius of curvature at a top of the wave crest and/or at a bottom of the wave trough in the waveform and ‘z’ denotes the wavelength of the waveform including the wave crest and the wave trough.

2. The heat exchanger in accordance with claim 1 , wherein the wave crest and the wave trough formed on each of the at least two opposed heat transfer members are arranged to have an angle of inclination of not less than 25 degrees on a cross section of the waveform including the wave crest and the wave trough.

3. The heat exchanger in accordance with claim 1 , wherein each of the at least two opposed heat transfer members includes multiple heat transfer sectional members parted at plural planes substantially perpendicular to the main stream of the fluid flow.

4. The heat exchanger in accordance with claim 1 , the heat exchanger comprising:
multiple heat transfer tubes arranged in parallel to one another as a pathway of a heat exchange medium,
wherein the at least two opposed heat transfer members are formed as multiple fin members attached to the multiple heat transfer tubes such as to be arranged perpendicular to the multiple heat transfer tubes in a heat exchangeable manner and to be overlapped in parallel to one another at a preset interval.

5. The heat exchanger in accordance with claim 1 , wherein the multiple continuous lines of the wave crests and the multiple continuous lines of the wave troughs are arranged to have the specific angle in the range of 25 degrees to 35 degrees relative to the main stream of the fluid flow.

6. The heat exchanger in accordance with claim 1 , wherein the wave crests and the wave troughs satisfy Inequality given below:
1.3×Re −0.5 <a/p< 0.1.

7. A heat exchanger configured to perform heat exchange by making a fluid flow in a main flow direction from an inlet to an outlet of the heat exchanger between at least two opposed heat transfer members, the heat exchanger comprising:
the at least two opposed heat transfer members configured with a heat transfer plane that defines the fluid flow thereon and configured with wave crests and wave troughs,
the wave crests and wave troughs having multiple continuous lines formed on the heat transfer plane and are arranged to have a preset angle in a specific angle range of 10 degrees to 60 degrees relative to the main flow direction from the inlet to the outlet,
the wave crests and the wave troughs are formed by a curved surface,
the multiple continuous lines of the wave crests and multiple continuous lines of the wave troughs are arranged to be bent multiple times to be symmetrically folded back about multiple folding lines arranged at a preset interval along the main flow direction, wherein a pitch of wave of the wave crests and wave troughs in a direction perpendicular to the main flow direction of the fluid flow is non-constant, a bend formed in the multiple continuous lines of the wave crests and multiple continuous lines of the wave troughs forms an apex that faces with the direction of the main flow direction, with arms of the apex extending in a direction opposite to the main flow direction, with respect to the apex of the bend,
the multiple continuous lines of the wave crests and wave troughs meander back and forth so as to extend across the heat transfer members in a direction transverse to the main flow direction, and thereby secondary flow, different from the main flow direction of the fluid flow, that flows along the surface of the wave crests and the wave troughs is generated on the surface of the heat transfer plane,
to generate the secondary flow effectively, the wave crests and the wave troughs being arranged to satisfy Inequality (1) given below:
1.3×Re −0.5 <a/p< 0.2  (1)

where ‘a’ denote an amplitude of a waveform including one wave crest and one wave trough, ‘p’ denotes a pitch as an interval between adjacent heat transfer planes of the at least two opposed heat transfer members, and ‘Re’ denotes a Reynolds number defined by a bulk flow rate and the pitch ‘p’,

each of the at least two opposed heat transfer members is structured to have the wave crest and the wave trough arranged to satisfy Inequality (2) given below:
0.25< W/z< 2.0  (2)

where ‘W’ denotes a folding interval of the V shape and ‘z’ denotes a wavelength of the waveform including the wave crest and the wave trough, and

each of the at least two opposed heat transfer members are structured to have the wave crest and the wave trough arranged to satisfy Inequality (3) given below:
0.25< r/z   (3)

wherein ‘r’ denotes a radius of curvature at a top of the wave crest and/or at a bottom of the wave trough in the waveform and ‘z’ denotes the wavelength of the waveform including the wave crest and the wave trough.

8. The heat exchanger in accordance with claim 7 , wherein the wave crest

Assignees

• Shikazono Naoki
• Fukuda Kentaro
• Univ Tokyo

Inventors

• Shikazono Naoki
• Fukuda Kentaro

Classifications

• F28D1/05383

  with multiple rows of conduits or with multi-channel conduits (F28D1/05391 takes precedence) · CPC title

• F28F1/126

  consisting of zig-zag shaped fins (F28F1/105 takes precedence) · CPC title

• F28F1/32 Primary

  the means having portions engaging further tubular elements · CPC title

• F28F1/38

  and being staggered to form tortuous fluid passages · CPC title