U.S. patent application number 13/648607 was filed with the patent office on 2014-04-10 for plate evaporative condenser and cooler.
This patent application is currently assigned to American Sino Heat Transfer LLC. The applicant listed for this patent is Zahid Ayub, Peng Peng. Invention is credited to Zahid Ayub, Peng Peng.
Application Number | 20140096555 13/648607 |
Document ID | / |
Family ID | 50431665 |
Filed Date | 2014-04-10 |
United States Patent
Application |
20140096555 |
Kind Code |
A1 |
Ayub; Zahid ; et
al. |
April 10, 2014 |
PLATE EVAPORATIVE CONDENSER AND COOLER
Abstract
An evaporator condenser has a condenser unit which has plural
plate units separated from one another by air gaps. Each plate unit
has first and second plates that are coupled together about a
perimeter thereof. Each plate unit has a first edge and an opposite
second edge. The first and second plates are coupled together along
at least one line so as to form a first channel that extends from
the first edge to the second edge in the second channel by
communicates with the first channel and extends back to the first
edge. The channels decrease in volume from an inlet to an
outlet.
Inventors: |
Ayub; Zahid; (Arlington,
TX) ; Peng; Peng; (Shanghai, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ayub; Zahid
Peng; Peng |
Arlington
Shanghai |
TX |
US
CN |
|
|
Assignee: |
American Sino Heat Transfer
LLC
Shanghai
CN
|
Family ID: |
50431665 |
Appl. No.: |
13/648607 |
Filed: |
October 10, 2012 |
Current U.S.
Class: |
62/305 |
Current CPC
Class: |
F28F 3/12 20130101; F28F
13/08 20130101; F25B 2339/041 20130101; F28D 5/02 20130101; F28D
1/035 20130101; F28D 2021/007 20130101; F25B 39/04 20130101; F28D
2021/0066 20130101; F28F 3/044 20130101 |
Class at
Publication: |
62/305 |
International
Class: |
F25B 39/04 20060101
F25B039/04 |
Claims
1. An evaporative condenser, comprising: a) a condenser unit; b) a
water sprayer located above the condenser unit; c) a fill section
located below the condenser unit; d) a basin located below the fill
section; e) at least one fan for flowing air through the condenser
unit and the fill section; f) the condenser unit comprising plural
plate units, separated from one another by air gaps, with each
plate unit comprising first and second plates coupled together
about a perimeter thereof, each plate unit having a first edge and
an opposite second edge, each plate unit having an inlet and an
outlet, the first and second plates coupled together along at least
one line so as to form a first channel that extends from the first
edge to the second edge and a second channel that communicates with
the first channel and extends back to the first edge, the first and
second plates coupled together at spots located in the channel.
2. The evaporative condenser of claim 1 wherein the first channel
extends from the inlet, further comprising a third channel that
extends to the outlet, the first channel having a larger volume
than the third channel.
3. The evaporative condenser of claim 2 further comprising an
intermediate channel between the first and third channels, the
intermediate channel having a smaller volume than the first channel
and having a larger volume than the third channel.
4. The evaporative condenser of claim 1 wherein the at least one
line extends from the first edge toward the second edge, the first
channel bounded by the one line and an outside edge, further
comprising a second line extending from the second edge toward the
first edge, the second channel bounded by the one line and the
second line.
5. The evaporative condenser of claim 4 wherein the one line and
the second line are discontinuous.
6. The evaporative condenser of claim 5 wherein the one line has
gaps that decrease in size from the first edge to the second edge
and the second line has gaps that decrease in size from the second
edge to the first edge.
7. The evaporative condenser of claim 6 wherein the one line has
gaps of equal size and the second line has gaps of equal size, the
gaps of the second line being misaligned with the gaps of the one
line in a direction perpendicular to the first and second
edges.
8. The evaporative condenser of claim 4 wherein the first channel
extends from the inlet, further comprising a third channel that
extends to the outlet, the third channel having a third line that
extends from one of the first or second edges to the other of the
first or second edges, the one line having a first gap for the
second edge, the third line having a third gap with the other of
the first or second edges, the first gap being larger than the
third gap.
9. The evaporative condenser of claim 1 wherein the one line is
continuous.
10. The evaporative condenser of claim 1 wherein the one line is
discontinuous.
11. The evaporative condenser of claim 1 wherein the plates in each
plate unit are coupled together at spots located in the first and
second channels, the spots arranged in a triangular pattern, which
triangular pattern has triangles with bases that are parallel to
the flow of fluid through the first and second channels.
12. The evaporative condenser of claim 1 wherein the plates in each
plate unit are coupled together at spots located in the first and
second channels, the spots arranged in a triangular pattern, which
triangular pattern has triangles with bases that are perpendicular
to the flow of fluid through the first and second channels.
13. The evaporative condenser of claim 1 wherein the plates in each
plate unit are coupled together at spots located in the first and
second channels, the spots arranged in a rectangular pattern, which
rectangular pattern has a side that is parallel to fluid flow
through the first and second channels.
14. The evaporative condenser of claim 1 wherein the plates in each
plate unit are coupled together at spots located in the first and
second channels, the spots arranged in a rectangular pattern, which
rectangular pattern has a side that is angled 15 to 60 degrees to
fluid flow through the first and second channels.
15. The evaporative condenser of claim 1 wherein each of the plate
units has sides, the plate units are oriented with respect to each
other along adjacent sides, further comprising frames extending
across the plate units and coupled thereto.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to heat exchangers and more
particularly to evaporative condensers and coolers.
BACKGROUND OF THE INVENTION
[0002] Evaporative condensers are condensers where water is sprayed
onto a heat exchanger to condense a gas into a liquid. For example,
in a refrigeration system, a compressor compresses a heat exchange
fluid, such as ammonia. The output of the compressor is hot, high
pressure ammonia gas. The gas is provided to a condenser, where it
condenses into a liquid. The liquid ammonia then passes through an
expansion valve, where it drops in pressure and decreases in
temperature to provide refrigeration.
[0003] In a conventional evaporative condenser, the heat exchanger
for the fluid is a set of coils or tubes. The ammonia gas flows
into the coils and condensed or liquid ammonia flows out.
[0004] It is desirable to make improvements over the conventional
coil condenser.
SUMMARY OF THE INVENTION
[0005] An evaporative condenser comprises a condenser unit and a
water sprayer located above the condenser unit. A fill section is
located below the condenser unit. A basin is located below the fill
section. At least one fan flows air through the condenser unit and
the fill section. The condenser unit comprises plural plate units
separated from one another by air gaps. Each plate unit comprises
first and second plates coupled together about a perimeter thereof.
Each plate unit has a first edge and an opposite second edge. Each
plate unit has an inlet and an outlet. The first and second plates
are coupled together along at least one line so as to form a first
channel that extends from the first edge to the second edge and a
second channel that communicates with the first channel and extends
back to the first edge. The first and second plates are coupled
together at spots located in the channel.
[0006] In accordance with one aspect, the first channel extends
from the inlet. A third channel extends to the outlet. The first
channel has a larger volume than the third channel.
[0007] In accordance with another aspect, there is an intermediate
channel between the first and third channels. The intermediate
channel has a smaller volume than the first channel and a larger
volume than the third channel.
[0008] In accordance with another aspect, the at least one line
extends from the first edge toward the second edge. The first
channel is bounded by the one line and an outside edge. A second
line extends from the second edge toward the first edge. The second
channel is bounded by the one line and the second line.
[0009] In accordance with another aspect, the one line and the
second line are discontinuous.
[0010] In accordance with still another aspect, the one line has
gaps that decrease in size from the first edge to the second edge
and the second line has gaps that decrease in size from the second
edge to the first edge.
[0011] In accordance with another aspect, the one line has gaps of
equal size and the second line has gaps of equal size. The gaps of
the second line are misaligned with the gaps of the one line in a
direction perpendicular to the first and second edges.
[0012] In accordance with another aspect, the first channel extends
from the inlet. A third channel extends to the outlet. The third
channel has a third line that extends from one of the first or
second edges to the other of the first or second edges. The one
line has a first gap for the second edge. The third line has a
third gap with the other of the first or second edges. The first
gap is larger than the third gap.
[0013] In accordance with another aspect, the one line is
continuous.
[0014] In accordance with another aspect, the one line is
discontinuous.
[0015] In accordance with another aspect, the plates in each plate
unit are coupled together at spots located in the first and second
channels. The spots are arranged in a triangular pattern. The
triangular pattern has triangles with bases that are parallel to
the flow of fluid through the first and second channels.
[0016] In accordance with another aspect, the plates in each plate
unit are coupled together at spots located in the first and second
channels. The spots are arranged in a triangular pattern. The
triangular pattern has triangles with bases that are perpendicular
to the flow of fluid through the first and second channels.
[0017] In accordance with another aspect, the plates in each plate
unit are coupled together at spots located in the first and second
channels. The spots are arranged in a rectangular pattern. The
rectangular pattern has a side that is parallel to the fluid flow
through the first and second channels.
[0018] In accordance with another aspect, the plates in each plate
unit are coupled together at spots located in the first and second
channels. The spots are arranged in a rectangular pattern. The
rectangular pattern has a side that is angled 15 to 60 degrees to
fluid flow through the first and second channels.
[0019] In accordance with another aspect, each of the plate units
has sides. The plate units are oriented with respect to each other
along adjacent sides. Frames extend across the plate units and are
coupled thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a schematic view of an evaporative condenser.
[0021] FIG. 2 is a side view of a plate unit, in accordance with
one embodiment.
[0022] FIG. 3 is a cross-sectional view of the plate unit, taken
along lines III-III of FIG. 2.
[0023] FIG. 4 is a side view of a plate unit, in accordance with
another embodiment.
[0024] FIG. 5 is a side view of a plate unit, in accordance with
another embodiment.
[0025] FIG. 6 is a side view of a plate unit, in accordance with
another embodiment.
[0026] FIG. 7 is an end view of the plate assembly.
[0027] FIG. 8 is a side view of a plate unit, in accordance with
another embodiment.
[0028] FIG. 9 is a side view of a plate unit, in accordance with
another embodiment.
[0029] FIGS. 9A and 9B are side views of a plate unit, in
accordance with other embodiments.
[0030] FIG. 10 is a side view of a plate unit, in accordance with
another embodiment.
[0031] FIG. 11 is a side view of a plate unit, in accordance with
another embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] FIG. 1 shows an evaporative condenser 11. Water is sprayed
onto a plate assembly 13 which is a heat exchanger. A fan 15 draws
air 17 through the wetted plate assembly 13 to provide evaporative
cooling and condensing of a fluid inside of the plate assembly
(typically from a gas into a liquid). The plate assembly 13
provides an efficient, cost effective condenser.
[0033] The various components of the evaporative condenser 11 will
now be described. The evaporative condenser 11 has a housing 19.
The plate assembly 13 is located in the housing. Below the plate
assembly is a fill or stuffing section 21. The fill section 21 has
layers that expose descending water to air flow. The layers can be
made of plastic, etc. Below the fill section 21 is a basin 23 to
catch the water. The housing also has a plenum 25 that communicates
with the plate assembly section and the fill section. The fan 15
draws air through the plate assembly 13, in through the fill
section 21, through demisters 27 or dehydrators, into the plenum 25
and out of the housing.
[0034] The plate assembly 13 includes a number of plate units 31
vertically oriented and spaced apart from each other. Referring to
FIGS. 2 and 3, a plate unit 31 is shown. Each plate unit has two
plates 33, each of generally rectangular shape. Each plate 33 is
metal, such as carbon steel or stainless steel. The plates are
coupled together along their outside edges 35A, 35B, 35C, 35D, with
edge or perimeter welds. Once coupled together, the plates form an
interior cavity 37. An inlet pipe 39 is provided at one corner of
the plate unit. An outlet pipe 41 is provided at another corner of
the plate unit. The inlet and outlet can be on the same side 35A as
shown in FIG. 2, or in opposite corners. The inlet and outlet pipes
39, 41 communicate with the interior cavity 37.
[0035] Channels 43 are formed in the interior cavity 37 by welding
the plates together along inside locations. In the embodiment shown
in FIG. 2, the fluid flows from the inlet pipe in the first edge
35A, in one channel to the opposite, or second edge 35C, and enters
the adjacent channel where it flows back to the first edge 35A and
so on in a zig-zag manner to the outlet 41. The channels are made
by lines 45 of welding (in the example shown in FIG. 2, there are
weld lines 45A, 45B, 45C, 45D, 45E, 45F and 45G). Thus, the channel
receiving fluid from the inlet pipe 39 is bounded by the outside
edge 35D and a weld line 45A extending from the first edge 35A
toward the second edge 35C. The weld line 45A stops short of the
second edge 35C leaving a gap 47A to allow fluid to exit the inlet
channel and enter the next channel. A second weld line 45B extends
from the second edge 35C toward the first edge 35A. This next
channel is formed by the first and second weld lines 45A, 45B. The
second weld line 45B stops short of the first edge 35A, leaving a
gap.
[0036] Thus, the channels 43 are formed by the weld lines 45A-45G
and the outside edges.
[0037] The volumes of the individual channels 43 change from the
inlet to the outlet. Because the plate unit operates as a
condenser, the volumes of the channels are larger near the inlet 39
than near the outlet 41. For example, and referring to the
orientation of FIG. 2, the height of the first two channels near
the inlet (the channels bound by the edge 35D and the weld line 45A
and the channel between weld lines 45A, 45B), is A, with the height
of the next few channels (bounded by weld lines 45B and 45C; 45C
and 45D; 45D and 45E; and 45E and 45F) is B, where A>B. The
height of the channels nearest the outlet (bounded by weld lines
45F and 45G and 45G and edge 35B) is C, where B>C. Because the
lengths of the channels are equal (from edge 35A to edge 35C), the
distance between the weld lines determines the channel volumes.
Alternatively, the cross-sectional areas of the channels decrease
from the inlet 39 to the outlet 41 where the cross-section is
perpendicular to the general flow of fluid in the channels.
[0038] Likewise, the gaps 47 at the ends of the weld lines, leading
from one channel to the next, change size, diminishing from the
inlet to the outlet. The first two gaps 47A nearest the inlet are
larger than the next few gaps 47B. The gap or gaps 47C nearest the
outlet is the smallest, with 47A>47B>47C.
[0039] If the plate unit operates as a cooler instead of a
condenser, the flow through the plate unit is reversed, from the
smaller channels to the larger channels to accommodate the
expansion fluid. If no phase change occurs in the plate unit, then
the channels will be of equal dimensions.
[0040] In addition to the weld lines 45, spot welding 49 is used in
or along the channels. The spot welds enhance heat transfer by
creating elliptical cross-sections of the channels (see FIG. 3).
Elliptical cross-sections of the channels are more efficient at
heat transfer than are circular cross-sections.
[0041] Fluid in the channels flow generally from one edge 35A to
the opposite edge 35C and back, and parallel to the weld lines 45.
Spot welding contributes to turbulent flow of fluid in the
channels. As the fluid flows in the channels, a spot weld 49
diverts flow around the weld. Such turbulent flow enhances heat
transfer.
[0042] The spot welds 49 can be arranged in pattern or
configuration. In FIG. 2, spot welds are arranged in a triangular
pattern, with each spot weld forming an apex of an equilateral
triangle. (In FIGS. 2, 4-6, dashed lines between spot welds 49
indicate the pattern). The triangles have bases 51 that are
parallel to the general fluid flow in the channels. FIG. 4
illustrates a spot weld pattern where the triangles are rotated 90
degrees so that the triangle bases 51 are perpendicular to the
general fluid flow in the channels. The pattern of FIG. 4 presents
a different aspect of the triangles of fluid flowing in the
channels around the spot welds than the pattern of FIG. 2.
[0043] FIG. 5 illustrates a spot weld pattern in a rectangular
arrangement. The sides 53 of the rectangles are parallel to the
edges 35 (35C, 35D) of the plate unit. FIG. 6 illustrates a
rectangular spot weld pattern rotated from that of FIG. 5. FIG. 6
shows the sides 53 oriented at 45 degrees relative to the weld
lines 45. However, the sides 53 could be oriented 15 to 60
degrees.
[0044] The distance between spot welds 49 can be varied according
to the design. The spot welds can be spaced apart a constant
distance. Alternatively, the spot welds can be located closer
together in the channels nearest the outlet than in the channels
nearest the inlet.
[0045] After the plate unit has been welded, the plates are
positioned together with little volume in the interior cavity.
Pressurized air is introduced into the interior cavity through the
inlet or outlet. This causes the unwelded portions of the plates to
expand outward as shown in FIG. 3.
[0046] The individual plate units 31 are assembled together into
the plate assembly 13. The plate units are parallel to each other
and separated from the adjacent plate units by gaps for air
circulation. Frames 55 extend across the edges of plate units 31 to
join them together (see FIG. 7). The frames 55 contact the outside
edges 35 of the plate units 31. The frames can be angle iron.
Alternatively, each frame can have notches 57 therein for receiving
an edge of a plate unit. The plate units may be welded to the
frames. The inlet pipes and outlet pipes are coupled to respective
headers 59 (see FIG. 1). The plate assembly 13 is mounted in the
housing 19.
[0047] In operation, referring back to FIG. 1, water is sprayed
from spray heads 61 onto the plate units 13. The water moves down
the plate units. Air is drawn across the plate units by the fan 15.
Fluid in the plate units enters the inlets as a gas and leaves the
outlets as a liquid. The water, now hot, falls onto the fill
section 21, where it is cooled by air flowing across the fill
section. The water then falls into the basin 23, where a pump 63
returns it to the spray head 65. A float switch 65 controls the
pump.
[0048] FIG. 8 illustrates another embodiment of the plate unit 31.
The plate units of FIGS. 8-10 are designed to handle an excess
amount of gas. In FIG. 2, the weld lines 45 dividing the channels
43 are continuous. In FIG. 8, the weld lines 71 are discontinuous
for those weld lines located closest to the inlet 39. Gaps 73 are
provided in the weld lines 71, wherein fluid can flow through the
gaps 73 from one channel to the next. As the weld lines extend from
the first edge 35A, there is a gap a, then gap b, gap c and gap d
between the end of the weld line and the second edge 35C. The next
weld line extends from the second edge 35C and has a gap a, then
gap b, gap c and gap d. For the gaps, a>b>c>d. Subsequent
weld lines 45 can be solid because the volume of gas
diminishes.
[0049] FIG. 9 shows another embodiment of the plate unit 31 where
the first two weld lines 71 have gaps 73 of uniform dimension. The
gaps in the second weld line are vertically staggered (referring to
the orientation shown in the drawing) from the gaps of the first
weld line. Subsequent weld lines 45 are solid.
[0050] FIG. 9A shows an alternate embodiment to FIG. 9. The
embodiment of FIG. 9A has the first two weld lines 71 with gaps 73
but lacks subsequent solid weld lines. FIG. 9B shows another
embodiment which has a single weld line 71 with gaps 73 but no
subsequent weld lines.
[0051] FIG. 10 shows another embodiment of the plate unit 31 where
the first weld line 71 is discontinuous and nonparallel to the
other weld lines. The weld line extends from the first edge 35A
toward the second edge 35C and inclines upward toward the upper
edge 35D so as to reduce the volume of the inlet channel at the
second edge. The gaps 73 can be of the same size or decreasing in
size: a>b>c>d>e. Subsequent weld lines 45 are
continuous and parallel.
[0052] FIG. 11 shows another embodiment of the plate unit 31. A
series of weld lines 71 is provided near the upper edge 35D. The
weld lines 71 are separated by gaps 73. The weld lines have first
and second ends 81, 83. The first ends 81 are progressively closer
to the upper edge 35D for those weld lines 81 that are closer to
the second edge 35B than to the first edge 35A. Likewise, the
second ends 83 are progressively closer to the upper edge 35D for
those weld lines 81 that are closer to the second edge 35B. Also
the second ends 83 are closer to the upper edge 35D than are the
first ends 81.
[0053] Thus, by providing plate units 31 for the condenser, the
condenser component can be made inexpensively since the plate units
are simply welded around the perimeter edges and then the interior
so as to form channels and also spot welding to increase the
turbulence of flow of fluid inside the plate units. The plate units
31 are then assembled together into a plate assembly 13 in an
inexpensive manner.
[0054] The plate assembly provides an efficient heat exchanger as
the exterior of the plate units has large surface areas for being
wetted with the water spray, while the interior provides
elliptically shaped channels to increase the surface area with the
fluid inside. In addition, the spot welding provides turbulence for
fluid flow.
[0055] The foregoing disclosure and showings made in the drawings
are merely illustrative of the principles of this invention and are
not to be interpreted in a limiting sense.
* * * * *