U.S. patent application number 13/768109 was filed with the patent office on 2013-10-24 for evaporator, especially for a waste gas heat recovery device.
The applicant listed for this patent is Eberspacher Climate Control Systems GmbH & Co. KG. Invention is credited to Stefan GESER.
Application Number | 20130277026 13/768109 |
Document ID | / |
Family ID | 47722277 |
Filed Date | 2013-10-24 |
United States Patent
Application |
20130277026 |
Kind Code |
A1 |
GESER; Stefan |
October 24, 2013 |
EVAPORATOR, ESPECIALLY FOR A WASTE GAS HEAT RECOVERY DEVICE
Abstract
An evaporator (1) for a waste heat recovery device includes a
plurality of evaporation devices (2) for the flow of a fluid. The
evaporation devices (2) are arranged in a stack-line manner in a
stacking direction (S). A plurality of rib structures (3) are
designed and arranged for the flow of a gas through them, in a gas
flow direction (G). Each evaporation device (2) has a pair of
plates (4). The first and second evaporator plates (5, 6) are
mutually complementary with one another and have a meandering
evaporation channel (9) each on a respective inner side (7, 8). The
inner sides (7, 8) of the first and second evaporator plate (5, 6)
are in flat contact with one another in a mounted state outside the
evaporation channel (9). Adjacent pairs of plates (4) are supported
with their respective outer sides (16, 17) on the rib structure
(3).
Inventors: |
GESER; Stefan; (Stuttgart,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Eberspacher Climate Control Systems GmbH & Co. KG |
Esslingen |
|
DE |
|
|
Family ID: |
47722277 |
Appl. No.: |
13/768109 |
Filed: |
February 15, 2013 |
Current U.S.
Class: |
165/166 |
Current CPC
Class: |
F28F 3/027 20130101;
F28D 21/0003 20130101; F28F 3/02 20130101; F28D 9/0056 20130101;
F28D 2021/0064 20130101 |
Class at
Publication: |
165/166 |
International
Class: |
F28F 3/02 20060101
F28F003/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 16, 2012 |
DE |
10 2012 202 361.5 |
Claims
1. An evaporator for a waste heat recovery device, the evaporator
comprising: a plurality of evaporation devices for the flow of a
fluid, the evaporation devices being arranged in a stack-like
manner in a stacking direction; and a plurality of rib structures
for the flow of a gas in a gas flow direction, wherein: each of the
evaporation devices comprise a pair of plates with a first
evaporator plate and with a second evaporator plate; the first
evaporator plates and the second evaporator plates are mutually
complementary to one another and each have a meandering evaporation
channel on a respective inner side; the first evaporator plates and
the second evaporator plates are in flat contact with one another
in a mounted state outside of an area of the evaporation channel;
and adjacent pairs of plates are supported at outer sides on an
adjacent one of the rib structures.
2. An evaporator in accordance with claim 1, wherein each rib
structure is arranged in a sandwich-like pattern between two
adjacent pairs of plates.
3. An evaporator in accordance with claim 1, wherein the gas flow
direction extends at right angles to the stacking direction.
4. An evaporator in accordance with claim 1, wherein: each
evaporation channel has a plurality of main flow sections, which
extend in a direction at right angles in relation to both the
stacking direction and the gas flow direction; and the main flow
sections that are adjacent are fluidically connected with one
another by means of connection sections extending in the gas flow
direction.
5. An evaporator in accordance with claim 1, wherein each
evaporation channel is essentially flat.
6. An evaporator in accordance with claim 1, wherein each rib
structure comprises a plurality of rows of ribs arranged next to
each other in relation to the gas flow direction and in a
corrugated.
7. An evaporator in accordance with claim 6, wherein: each row of
ribs comprises elevations and depressions following each other
alternatingly, which are connected with one another by means of
respective webs; and rows of ribs that are adjacent to each other
in relation of the gas flow direction are offset in relation to one
another in relation to a position of elevations and
depressions.
8. An evaporator in accordance with claim 1, wherein: each
evaporation device has an inlet area with an inlet opening and an
outlet area with an outlet opening for the inlet and outlet of the
fluid; and adjacent inlet openings are in fluidic connection with
one another and adjacent outlet openings are in fluidic connection
with one another in a mounted state of evaporator.
9. An evaporator in accordance with claim 8, wherein each inlet
opening comprises an inlet dome on an outer side of one of the
first evaporator plates and second evaporator plates and each
outlet opening comprises an outlet on an outer side of one of the
first evaporator plates and second evaporator plates.
10. An evaporator in accordance with claim 9, wherein each inlet
dome and each outlet dome has an essentially ring-shaped cover
surface.
11. An evaporator in accordance with claim 8, further comprising:
an evaporator fluid inlet opening; and an evaporator fluid outlet
opening, wherein; the evaporator fluid inlet opening and the
evaporator fluid outlet opening are in fluidic connection with the
inlet openings and the outlet openings of the evaporation devices;
and the evaporator fluid inlet opening and the evaporator fluid
outlet opening are arranged in the gas flow direction.
12. An evaporator in accordance with claim 1, further comprising at
least one of: a feeding line of a funnel-shaped design for feeding
gas into the rib structures; and a drain line of a funnel-shaped
design for removing gas from the rib structures.
13. An evaporator in accordance with claim 1, further comprising: a
housing for a fluidic limitation of a gas path of gas flowing
through the plurality of rib structures.
14. An evaporator in accordance with claim 1, wherein the first and
second evaporator plates are soldered to one another in a mounted
state.
15. An evaporator in accordance with claim 6, wherein the rows of
ribs are manufactured from steel.
16. An evaporator for a waste heat recovery device, the evaporator
comprising: a plurality of evaporation devices for the flow of a
fluid, the evaporation devices being arranged adjacent to each
other to form a stack in a stacking direction, each evaporation
device comprising a pair of plates, each pair of plates comprising
a first evaporator plate and a second evaporator plate, the first
evaporator plate having a shape that is essentially a mirror image
of the shape of the second evaporator plate, each of the first
evaporator plate and the second evaporator plate having a contact
surface portion and a channel portion, wherein the first evaporator
plate and the second evaporator plate are in flat contact with one
another at the contact surface portion and the channel portion of
the first evaporator plate and the channel portion of the second
evaporator plate form an evaporation channel; and a plurality of
rib structures for the flow of a gas in a gas flow direction, each
evaporation device being supported at an outer side by an adjacent
one of the rib structures.
17. An evaporator in accordance with claim 16, wherein each rib
structure is arranged in a sandwich-like pattern between adjacent
evaporation devices.
18. An evaporator in accordance with claim 16, wherein: each rib
structure comprises a plurality of rows of ribs arranged next to
each other in relation to the gas flow direction; and the gas flow
direction extends at right angles to the stacking direction.
19. An evaporator in accordance with claim 16, wherein: each
evaporation device has an inlet area with an inlet opening and an
outlet area with an outlet opening for the inlet and outlet of the
fluid; adjacent inlet openings are in fluidic connection with one
another and adjacent outlet openings are in fluidic connection with
one another; each evaporation channel has a plurality of main flow
sections, which extend in a direction at right angles in relation
to both the stacking direction and the gas flow direction; each
evaporation channel has a plurality of connection sections
extending in the gas flow direction; the main flow sections that
are adjacent to each other are fluidically connected with one
another by the connection sections; and each channel portion is
essentially flat.
20. An evaporator in accordance with claim 19, further comprising:
a housing for a fluidic limitation of a gas path of gas flowing
through the plurality of rib structures; an evaporator fluid inlet
opening; and an evaporator fluid outlet opening, wherein; the
evaporator fluid inlet opening and the evaporator fluid outlet
opening are in fluidic connection with the inlet openings and the
outlet openings of the evaporation devices; and the evaporator
fluid inlet opening and the evaporator fluid outlet opening are
arranged in the gas flow direction.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority under 35
U.S.C. .sctn.119 of German Patent Application 10 2012 202 361.5
filed Feb. 16, 2012, the entire contents of which are incorporated
herein by reference.
FIELD OF THE INVENTION
[0002] The present invention pertains to an evaporator, especially
for a waste heat recovery device.
BACKGROUND OF THE INVENTION
[0003] Evaporators, by means of which the working medium of the
closed cycle can be evaporated, while the heat needed for this is
removed from the waste gas of an internal combustion engine, are
used in waste heat recovery devices that are based on the principle
of a Rankine cycle or a Rankine-Clausius cycle. Such an evaporator
correspondingly contains a gas path for the waste gas, on the one
hand, and an evaporation path for the working medium to be
evaporated, on the other hand.
[0004] Such an evaporator may be designed, for example, as a plate
heat exchanger and correspondingly have a plurality of channel
plate arrays, which are stacked in a stacking direction, wherein a
gas path is formed between two adjacent channel plate arrays each,
and a gas, by means of which the heat needed for the evaporation of
the liquid can be fed, can be sent through said gas path. The
corresponding channel plate array may preferably contain a liquid
inlet, a steam outlet and a channel connecting the liquid inlet
with the steam outlet, said channel forming, for example, a
multiply deflected evaporation path for the liquid to be
evaporated.
SUMMARY OF THE INVENTION
[0005] An object of the present invention is to provide an improved
embodiment for an evaporator of the type mentioned in the
introduction or for a waste heat recovery device equipped
therewith.
[0006] The evaporator according to the present invention comprises
a plurality of evaporation devices for the flow of a fluid, which
are arranged one on top of another in a stack-like manner in a
stacking direction, and a plurality of rib structures, which are
designed for the flow of a gas through them in a gas flow
direction. Each evaporation device has a pair of plates with a
first evaporator plate and a second evaporator plate. The first and
second evaporator plates, which have a mutually complementary
design, have a meandering evaporation channel on a respective inner
side. The inner sides of the first and second evaporator plates are
in flat contact with one another in an area outside of the area of
the evaporation channel, in a mounted state. Adjacent pairs of
plates being supported by their outer sides on such a rib
structure.
[0007] It is possible by means of the rib structures provided for
supporting adjacent pairs of plates to manufacture the pairs of
plates with a very small material thickness and yet ensure a
necessary mechanical stability of the evaporator according to the
present invention, especially in respect to the mechanical
stiffness thereof. At the same time, an especially intense thermal
interaction can be achieved between the rib structures through
which a gas flows and the evaporation devices through a fluid flows
due to the small material thickness of the pairs of plates.
[0008] A preferred dimension for the thickness of the first and
second evaporator plates may be preferably between 0.2 mm and 0.5
mm and at most preferably approximately 0.4 mm.
[0009] In a preferred embodiment, the rib structure is arranged in
a sandwich-like pattern between two adjacent pairs of plates. This
makes it possible to manufacture a mechanically especially stable,
but also highly compact evaporator.
[0010] The direction of gas flow is preferably at right angles to
the stacking direction. The provision of a large number of rib
structures can nevertheless be combined with a highly compact
design in this manner.
[0011] In one embodiment variant, it is conceivable that the
evaporation channel has a plurality of main flow sections, which
extend at right angles in respect to both the stacking direction
and the gas flow direction, wherein adjacent main flow sections are
fluidically connected with one another by means of connection
sections extending in the gas flow direction. A crossed counterflow
principle, which makes possible an especially good thermal
interaction of the gas with the fluid, can be obtained in this
manner for the evaporator concerning the flow of a fluid through
the evaporation devices and the flow of gas through the rib
structures.
[0012] In one embodiment, which likewise represents a variant, the
evaporation channel has an essentially flat flow cross section for
the purpose of a very compact design. "Flat" means here that an
effective width of the evaporation channel in the flow cross
section is substantially greater than a height of the evaporation
channel, which is defined by a direction directed at right angles
to a plane defined by the evaporator plates. The width of the
evaporation channel may be especially 4 times, 6 times, 8 times or
10 times the height. Such a flat design of the evaporation channel
also brings about a pronounced interaction of the gas flowing
through the rib structures with the fluid flowing through the
evaporation devices, which facilitates the evaporation thereof.
[0013] In an especially preferred embodiment, the rib structure
comprises a plurality of rows of ribs arranged next to each other
in relation to the gas flow direction and are corrugated and
especially corrugated in a rectangular manner. The efficiency of
the thermal interaction can be further increased on the gas side by
means of such rows of ribs.
[0014] It is conceivable in one embodiment variant that each row of
ribs consists of elevations and depressions alternating following
each other, which are each connected with one another by means of
webs, with rows of ribs that are adjacent to each other in relation
to the gas flow direction being arranged offset in relation to one
another in relation to the positions of elevations and depressions.
An especially space-saving technical embodiment of the rib
structures is possible in this manner.
[0015] In an especially preferred embodiment, each evaporation
device has an inlet area each with an inlet opening and an outlet
area with an outlet opening for the inlet and outlet of the fluid,
where adjacent inlet openings are in fluidic connection with one
another and adjacent outlet openings are in fluidic connection with
one another in a mounted state of the evaporator.
[0016] In one embodiment variant, the inlet opening and the outlet
opening are designed each as an inlet dome and outlet dome provided
on the outer side of the first and second evaporator plates.
Despite such a space-saving design, this ensures a large flow
cross-section of the inlet and outlet openings for the fluid
flowing through the evaporation devices.
[0017] The inlet dome and outlet dome preferably have each an
essentially ring-shaped cover surface. Adjacent evaporator plates
can be fastened to one another in a simple manner, especially by
soldering, by means of such a cover surface.
[0018] In one embodiment of an especially compact design, the inlet
dome and the outlet dome each taper conically in the direction of
the adjacent evaporation devices.
[0019] For the purpose of feeding fluid into the evaporation
devices of the evaporator in a space-saving manner, the evaporator
may have, in one embodiment variant, a fluid inlet opening and a
fluid outlet opening, which are fluidically connected each with the
inlet openings and outlet openings of the evaporation devices,
respectively, said fluid inlet opening and said fluid outlet
opening being arranged in the direction of gas flow.
[0020] The evaporator may, furthermore, preferably have a feeding
line of a funnel-shaped design for feeding the gas into the rib
structures and/or a drain line of a funnel-shaped design for
removing the gas from the rib structures.
[0021] It is conceivable in one embodiment variant that the
evaporator comprises a housing for fluidically limiting a gas path
of the gas flowing through the plurality of rib structures. It is
thus unnecessary to provide an outer fluidic limitation of the rib
structures, which reduces the total number of components needed for
the evaporator.
[0022] The first and second evaporator plates may be soldered to
one another in a mounted state, especially by means of Ni-based
solders, in an embodiment that can be manufactured in an especially
simple manner.
[0023] The rows of ribs may be made of steel, preferably stainless
steel, for the purpose of providing an especially stable
embodiment.
[0024] Further important features of the present invention appear
from the subclaims, from the drawings and from the corresponding
description of the figures on the basis of the drawings.
[0025] It is apparent that the above-mentioned features, which will
also be explained below, can be used not only in the particular
combination indicated, but in other combinations or alone as well
without going beyond the scope of the present invention.
[0026] Preferred embodiments of the present invention are shown in
the drawings and will be explained in more detail below, with
identical reference numbers relating to identical or similar or
functionally identical components. The various features of novelty
which characterize the invention are pointed out with particularity
in the claims annexed to and forming a part of this disclosure. For
a better understanding of the invention, its operating advantages
and specific objects attained by its uses, reference is made to the
accompanying drawings and descriptive matter in which preferred
embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In the drawings:
[0028] FIG. 1 is a schematic exploded isometric view of an
evaporator according to the present invention;
[0029] FIG. 2 is a schematic isometric view of an evaporation
device of the evaporator in a non-mounted state;
[0030] FIG. 3 is a schematic isometric view showing a plurality of
evaporation devices of the evaporator in a mounted state;
[0031] FIG. 4 is side view showing an inlet dome of an evaporation
device;
[0032] FIG. 5 is a schematic isometric view of a rib structure of
the evaporator;
[0033] FIG. 6 is a longitudinal sectional view showing the
evaporator according to FIG. 1; and
[0034] FIG. 7 is a schematic isometric view of the mounted
evaporator according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] Referring to the drawings in particular, the evaporator
according to the present invention, which may preferably be
designed according to the cross counterflow principle, is
designated by 1 in FIG. 1. The different components of the
evaporator 1 are shown at spaced locations from one another
(exploded) in the view in FIG. 1 in order to improve the
possibility of representation.
[0036] Evaporator 1 comprises a plurality of evaporation devices 2
for the flow of a fluid, which are arranged one on top of another
in a stack-like manner, and a plurality of rib structures 3, which
are intended for the flow of a gas through them in a gas flow
direction G. Gas flow direction G extends at right angles to the
stacking direction S. Each evaporation device 2 has a pair of
plates 4 with first and second evaporator plates 5, 6.
[0037] Such a pair of plates 4 with first and second evaporator
plates 5, 6 is shown in FIG. 2 as an example in a non-mounted
state. The first and second evaporator plates 5, 6 have mutually
complementary designs and have a meandering evaporation channel 9
on a respective inner side 7, 8. In a mounted state, not shown in
FIG. 2, the inner sides 7, 8 of the first and second evaporator
plates are in flat contact with one another in an area outside of
an area of the evaporation channel 9.
[0038] Evaporation channel 9 may have a plurality of main flow
sections 10, which extend in a direction at right angles O in
relation to both the stacking direction S and the gas flow
direction G. Adjacent main flow sections 10 may be fluidically
connected with one another by means of connection sections 11 each
extending in the gas flow direction G.
[0039] Evaporation channel 9 may have an essentially flat design.
"Flat" is defined here such that an effective width B of the
evaporation channel is substantially greater in relation to a flow
cross section than a height H of evaporation channel 9, which is
defined by a direction extending at right angles to a plane defined
by the evaporator plates. This is shown schematically in a
schematic diagram supplementing FIG. 2 by reference number 40. This
schematic diagram shows a flow cross section of evaporation channel
9. Width B of evaporation channel 9 maybe, in respective
alternative variants, especially 4 times, 6 times, 8 times or 10
times the height H. A large flow cross section can be combined in
this manner with a large effective interaction surface (between
fluid and gas) and with a compact design.
[0040] Each evaporation device 2 may have an inlet area 12 with an
inlet opening 14 and an outlet area 13 with an outlet opening 15
for the inlet and outlet of a fluid. Adjacent inlet openings 14 may
be in fluidic connection with one another in a mounted state of the
evaporation devices 2, and adjacent outlet openings 15 may
correspondingly also be in fluidic connection with one another.
This becomes clear especially from the view in FIG. 3, which shows
a plurality of pairs of plates 4 with a plurality of inlet openings
14 in a mounted state.
[0041] Both inlet opening 14 and outlet opening 15 may be designed
each as a respective inlet dome 18 and outlet dome 19 provided on
an outer side 16, 17 of the first and second evaporator plates 5,
6.
[0042] FIG. 4 shows as an example such an inlet dome 18 in a side
view. Both inlet dome 18 and the outlet dome may taper conically in
the direction of the adjacent evaporation devices. A taper angle
may be between approximately 40.degree. and 60.degree. and
preferably approximately 50.degree..
[0043] As can be determined from the view in FIG. 2, inlet dome 18
and outlet dome 19 may have an essentially ring-shaped cover
surface 20, 21 each. Especially good soldering of adjacent inlet
and outlet domes 18, 19, for example, by means of an Ni-based
solder, is possible in this manner.
[0044] FIG. 5 shows a rib structure 3 according to the present
invention. Rib structure 3 comprises here a plurality of rows of
ribs 22 arranged next to each other and in a rectangularly
corrugated manner in relation to the gas flow direction G. Rows of
ribs 22 may be manufactured from steel, preferably from stainless
steel. Each row of ribs 22 consists of elevations 23 and
depressions 24 alternatingly following each other, which are
connected with one another via webs 25. Adjacent rows of ribs 22
are arranged offset in relation to one another in relation to the
positions of elevations 23 and depressions 24. Improved thermal
interaction can be achieved in this manner between rib structures 3
and evaporation devices 2.
[0045] Based on the view in FIG. 1, the arrangement of the rib
structures 3 relative to the evaporation devices 2 will be
explained below. Accordingly to this view, each rib structure 3 is
arranged in a sandwich-like pattern between two adjacent pairs of
plates 4, Adjacent pairs of plates 4 are supported according to the
present invention with their respective outer sides 16, 17 (cf.
FIG. 2) on a rib structure 3.
[0046] Evaporator 1 may comprise, furthermore, a housing 26 for
fluidically limiting a gas path of the gas flowing through the
plurality of rib structures 3. It is thus unnecessary to provide an
outer fluidic limitation of the rib structures 3 separately.
[0047] Evaporator 1 may have, furthermore, a feeding line 27 of a
funnel-shaped design (cf. FIG. 1) for feeding the gas into the rib
structures 3 and a drain line 28 of a funnel-shaped design for
removing the gas from the rib structures 3. It is clear that other
geometries are also conceivable in variants concerning the design
of feed line 27 and drain line 28.
[0048] FIG. 6 shows an evaporator 1 according to the present
invention in a longitudinal sectional view. It becomes clear from
this view that evaporator 1 can have a fluid inlet opening 29 and a
fluid outlet opening 30, which are fluidically connected with the
inlet openings 14 and outlet openings 15 of the evaporation devices
2, respectively. Fluid inlet opening 29 and fluid outlet opening 30
are preferably arranged in the gas flow direction G. A gas stream,
especially of a waste gas, is designated by arrows with the
references number 31 in FIG. 1.
[0049] Finally, FIG. 7 shows a perspective view of an evaporator 1
in a mounted state.
[0050] The mode of operation of evaporator 1 will be explained
below in reference to the drawings explained above. A hot gas,
especially a waste gas, for example, from an internal combustion
engine of a motor vehicle, can enter in the direction of the gas
flow direction G in the rib structures 3 of the evaporation devices
2 and thus reaches the rows of ribs 22. Since adjacent pairs of
plates 4 of the evaporation device 2 are supported at the rib
structures 3, strong thermal interaction of the rib structures 3
with the evaporation devices 2 is ensured. Consequently, strong
thermal interaction of a gas flowing through the rib structures 3
can also take place with a fluid flowing through the evaporation
channels 9 of the evaporation devices 2. By means of such a thermal
interaction, the hot gas can be cooled very effectively by means of
such a thermal interaction before discharge from the rib structure
3 while the fluid flowing through the evaporation devices 2
evaporates.
[0051] While specific embodiments of the invention have been shown
and described in detail to illustrate the application of the
principles of the invention, it will be understood that the
invention may be embodied otherwise without departing from such
principles.
* * * * *