U.S. patent number 3,627,039 [Application Number 04/869,108] was granted by the patent office on 1971-12-14 for heat exchanger, especially for nonstationary gas turbines.
This patent grant is currently assigned to Daimler-Benz Aktiengesellschaft. Invention is credited to Eberhard Tiefenbacher.
United States Patent |
3,627,039 |
Tiefenbacher |
December 14, 1971 |
HEAT EXCHANGER, ESPECIALLY FOR NONSTATIONARY GAS TURBINES
Abstract
A heat exchanger in which one of the two media is conducted
through tubes while the other medium flows externally along the
tubes in counterflow principle. The tubes are arranged in several
planes axially parallel to one another and the ends of the tubes,
flattened off into rectangles, are combined in a common mounting
for the connection of a group of tubes to a respective inlet or
outlet aperture.
Inventors: |
Tiefenbacher; Eberhard
(Ludwigsburg, DT) |
Assignee: |
Daimler-Benz Aktiengesellschaft
(Stuttgart-Unterturkheim, DT)
|
Family
ID: |
27436799 |
Appl.
No.: |
04/869,108 |
Filed: |
October 24, 1969 |
Current U.S.
Class: |
165/158; 165/165;
165/175; 29/890.043; 165/172; 165/178; 165/DIG.434 |
Current CPC
Class: |
F28D
7/0041 (20130101); F28F 9/182 (20130101); F28F
1/045 (20130101); F28F 9/0221 (20130101); Y10S
165/434 (20130101); Y10T 29/49373 (20150115) |
Current International
Class: |
F28F
1/04 (20060101); F28F 9/04 (20060101); F28F
9/18 (20060101); F28F 1/02 (20060101); F28D
7/00 (20060101); F28F 9/02 (20060101); F28f
009/02 () |
Field of
Search: |
;165/164,165,166,167,157,158,152,148,153,173,175,178
;29/157.3,157.4 ;113/118 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
838,466 |
|
Jun 1960 |
|
GB |
|
352,602 |
|
Jun 1905 |
|
FR |
|
Primary Examiner: Davis, Jr.; Albert W.
Claims
I claim:
1. A heat exchanger comprising a housing, tube means arranged on
the inside of said housing for conducting one of two fluid media
participating in the heat exchange, the other fluid medium being
conducted around the external surfaces of said tube means
substantially in counterflow to said one fluid medium, said tube
means being arranged axially parallel in a plurality of tube
planes, each tube plane including a plurality of tube means with
rectangular end openings in abutting relationship with the
rectangular end openings of adjacent tube means, the rectangular
end openings at one end of said tube means terminating in a common
plane where they are connected to a common collecting flange to
form an inlet for said one fluid medium, the rectangular end
openings at the other end of said tube means terminating in a
common plane where they are connected to a common collecting flange
to form an outlet for said one fluid medium, said tube planes being
spaced from one another in parallel relationship by spacing strips
extending transversely to the longitudinal extent of the tube means
and arranged adjacent the respective rectangular end openings to
form a tube floor for the tubes of one plane, said strips being of
a thickness corresponding to the rectangular height of the tube
ends and wherein alternate strips are folded over on themselves at
their ends to abut the first tube means of the adjacent tube plane
for staggering the tube means of one plane with respect to the tube
means of another plane.
2. A heat exchanger according to claim 1, characterized in that
said housing has a curved interior configuration in the area
adjacent the respective ends of said spacing strips.
3. A heat exchanger according to claim 2, characterized in that the
bar means are provided at the ends thereof with slots, by means of
which they are adapted to be inserted into flange means at the
housing means.
4. A heat exchanger according to claim 1, characterized in that the
strips exhibit slots at their ends for engagement with the
collecting flanges of the housing and in that the outermost strip
is provided with an inclined clamping surface to aid in the
assembly of the tube means within the housing.
5. A heat exchanger according to claim 1, characterized in that
inlet and outlet means for the other fluid medium are arranged
laterally directly adjacent the bottoms of the rectangular cross
section portion of the tube means.
6. A heat exchanger according to claim 4, characterized in that
inlet and outlet means for the other fluid medium are arranged
laterally directly adjacent the bottoms of the rectangular cross
section portion of the tube means.
7. A heat exchanger according to claim 1, characterized in that
each of the tube means is cylindrical along a substantial portion
thereof and that the tube means of two adjacent planes are mutually
offset by an amount corresponding to approximately the diameter of
the tube means.
8. A heat-exchanger according to claim 7, characterized in that
said housing has a curved interior configuration in the area
adjacent the respective ends of said spacing strips.
Description
The present invention relates to a heat exchanger, especially for
nonstationary gas turbines, which consists of pipes arranged on the
inside of a housing or the like, through which is conducted one of
the two media participating in the heat exchange whereas the other
medium moves externally along the pipes in counterflow.
The demand is made of heat exchangers for portable or nonstationary
gas turbines that they are to be as light weight as possible and
are to possess as small dimensions as possible. However, experience
has demonstrated that this requirement can be fulfilled best if the
heat exchangers are equipped with pipes and the media are conducted
through the heat exchanger according to the counterflow principle.
Heat exchangers operated countercurrent or counterflow possess, by
reason of the favorable temperature distribution, a small
heat-transferring surface and therewith a smaller volume and weight
than other types of constructions. Nevertheless, the known types of
constructions have proved still too heavy and too space consuming
for different applications in nonstationary gas turbines,
especially for the motor vehicle or the aircraft construction.
The present invention aims at creating a heat exchanger which
possesses particularly small dimensions and low weight and which
can be manufactured in a simple manner. Additionally, a heat
exchanger is to be created which, by reason of its construction,
can be adapted without difficulties to the contours of housings or
the like for the purpose of space saving and is utilizable in the
form of structural units. The present invention essentially
consists in that the pipes or tubes are arranged axially parallel
in several planes disposed one above the other or one adjacent the
other and the ends thereof are respectively combined in a common
end-face-mounting means for the connection of the group of tubes to
a respective inlet or outlet aperture for the medium flowing
through the tubes. Appropriately, provision may be made that the
inlet and/or the outlet for the medium, not flowing through the
tubes, is arranged laterally directly behind the end-face-mounting
means of the tube group and the ends of the tubes or pipes are
flattened off within this area into rectangles. In this manner,
wide inflow or outflow channels are formed within the area of the
flattened off ends of the tubes which assure a rapid and good
distribution of the medium moving externally along the tubes from
the inlet toward the outlet. Furthermore, the tubes or pipes
arranged in different planes can be held at spacings in a simple
manner by bars abutting at the rectangles.
An extraordinarily favorable construction results if the
rectangular ends of the tubes of each plane are disposed without
gap adjacent one another. Such a type of construction is
structurally very simple, on the one hand, because only very few
individual parts differing from one another are necessary.
Additionally, the pressure losses in the inflow and outflow part
can be kept very small and the soldering or brazing operation can
be simplified. It is particularly favorable if the
end-face-mounting means for the pipes or tubes are constructed
directly as end face flanges for the housing of the heat
exchanger.
In order to achieve a favorable heat exchange, provision may be
made that the tubes of two adjoining planes are mutually offset in
the direction of these planes, preferably by the amount of the
diameter of the tubes. Such an arrangement of the tubes produces
uniform gaps between the tubes or pipes and therewith a uniform
flow on the outside of the tubes so that extraordinarily favorable
conditions exist for the heat transfer. It is thereby favorable if
the thickness of the bars corresponds to the height of the
rectangular ends of the tubes and if each second bar is bent back
or folded back at its end. With such a type of bar, the different
number of the tubes or pipes disposed mutually offset in adjacent
planes can be compensated for.
Frequently it is necessary for reasons of rigidity to construct the
outer housing of a heat exchanger curved. Provision may be made in
connection therewith in an advantageous manner that the thickness
of the bars corresponds to the height of the rectangular ends of
the tubes, and each bar is bent back at its end. It is achieved by
this measure that all bars can be manufactured with the same length
whereas they can simultaneously compensate for the differences in
the different planes provided with tubes. Furthermore, with this
type of construction, an adaptation of the heat exchanger to the
contours of engines or the like and therewith a space saving can be
achieved.
The bars, for the purposes of securing at the housing and of easier
assembly, may be advantageously provided at the ends thereof with
slots, by means of which they engage into the flanges of the
housing.
Accordingly, it is an object of the present invention to provide a
heat exchanger, especially for nonstationary gas turbines, which
avoids by simple means the aforementioned shortcomings and
drawbacks encountered in the prior art.
Another object of the present invention resides in a heat exchanger
which is of extreme light weight and small dimensions.
A further object of the present invention resides in a heat
exchanger which is not only small in dimension and light in weight
but which can also be manufactured in a simple manner.
Still a further object of the present invention resides in a heat
exchanger that can be readily adapted to the contours of other
structural parts.
These and further objects, features, and advantages of the present
invention will become more obvious from the following description
when taken in connection with the accompanying drawing which shows,
for purposes of illustration only, several embodiments in
accordance with the present invention, and wherein:
FIG. 1 is a somewhat schematic perspective view of a heat exchanger
in accordance with the present invention, partially cut away;
FIG. 2 is a partial perspective view, partly cut away, of a
modified embodiment of a heat exchanger in accordance with the
present invention, which includes a particular type of securing of
the spacer bars for the tubes at the housing flange;
FIG. 3 is a partial cross-sectional view through the inlet or
outlet channels within the heat exchanger constructed in accordance
with the present invention and taken along line III--III in FIG.
2;
FIG. 4 is a somewhat schematic partial perspective view, partly cut
away, of a modified embodiment of a heat exchanger in accordance
with the present invention in which the tubes are mutually
offset;
FIG. 5 is a somewhat schematic elevational view of an arrangement
of a heat exchanger in accordance with the present invention about
a turbine; and
FIG. 6 is a somewhat schematic, partial elevational view of the
securing of the tubes in a heat exchanger according to FIG. 5.
Referring now to the drawing where like reference numerals are used
throughout the various views to designate like parts, and more
particularly to FIG. 1, the pipes or tubes 2 are arranged axially
parallel to one another on the inside of the heat exchanger housing
1 in several planes. The medium to be heated or cooled flows, for
example, through the tubes 2 which are combined at the ends of the
heat exchanger in a respective common, end-face-mounting means that
is constructed as a flange of the housing. The heating or cooling
medium flows in through an inlet 3 laterally directed to the rear
of the end face flange of the heat exchanger and proceeds in
counterflow to the medium to be heated or cooled up to the rear
wall of the heat exchanger and is discharged thereat laterally
through the outlet 4. The tubes 2 are flattened off rectangularly
at the ends thereof within the areas of the inlet and outlet 3 and
4 of the medium to be heated or cooled and are arranged adjacent
one another without gaps. The individual planes of the tubes are
determined and arranged at predetermined distance to one another by
spacer bars 5.
The bars 6 according to FIG. 2 are provided with slots 7 which
engage in a flange 8 of the heat exchanger housing 1. A greater
rigidity is achieved thereby and additionally a simplification is
realized during the assembly while a better stability is assured
during the transport and during the soldering or brazing in the
furnace.
As can be readily seen from FIG. 3, relatively large interstices or
intermediate spaces 9 are present between the individual planes of
pipes or tubes 2 within the area of inlet and outlet apertures of
the heating or cooling medium so that the medium can distribute
itself uniformly over the entire heat exchanger. The uppermost bar
10 is constructed with an inclined surface 11 for assembly reasons.
This bar 10 may thus produce a clamping effect so that the assembly
is simplified.
The tubes 12 of the heat exchanger according to FIG. 4 are mutually
offset in mutually adjoining planes. With such an offset
arrangement more uniform intermediate spaces between the individual
tubes 12 result so that a more favorable heat transfer is made
possible. All bars 13 possess a thickness that corresponds to the
height of the rectangularly flattened off tubes 12. Each second bar
13 is bent back or folded over at its end in order to be able to
compensate for the differing number of the tubes 12 of two adjacent
planes. The bars 6, 13 are also slotted and are inserted with the
slots thereof in a flange 8 of the heat exchanger housing.
FIG. 5 illustrates schematically the arrangement of a heat
exchanger according to the present invention about a turbine 14.
For that purpose, the exchanger is constructed curved.
Advantageously also in this case the individual pipes 15 are
arranged mutually offset in different planes.
As illustrated in FIG. 6, in the embodiment of FIG. 5, the bars 16
may also be bent back or folded back at the ends thereof in a
structurally simple manner. The bars 16 thereby all possess the
same length prior to their installation and assembly. For the
purpose of securing at the heat exchanger housing 17, a slot 18 is
milled into the bars which corresponds to the curvature of the heat
exchanger housing. This slot 18 will be milled in only, when the
bars 16 are already assembled into a structural unit. If one were
to dispense with the bars, then each tube would have to be provided
at the outer contour with a different curvature.
While I have shown and described only several embodiments in
accordance with the present invention, it is understood that the
same is not limited thereto but is susceptible of numerous changes
and modifications as known to those skilled in the art, and I
therefore do not wish to be limited to the details shown and
described herein but intend to cover all such changes and
modifications as are within the scope of those skilled in the
art.
* * * * *