U.S. patent application number 12/875748 was filed with the patent office on 2011-03-10 for vapor compression system.
This patent application is currently assigned to JOHNSON CONTROLS TECHNOLOGY COMPANY. Invention is credited to Paul DE LARMINAT, Satheesh KULANKARA, Jeb SCHREIBER.
Application Number | 20110056664 12/875748 |
Document ID | / |
Family ID | 44624943 |
Filed Date | 2011-03-10 |
United States Patent
Application |
20110056664 |
Kind Code |
A1 |
DE LARMINAT; Paul ; et
al. |
March 10, 2011 |
VAPOR COMPRESSION SYSTEM
Abstract
A distributor for use in a vapor compression system including an
enclosure configured to be positioned in a heat exchanger having a
tube bundle comprising a plurality of tubes extending substantially
horizontally in the heat exchanger. A plurality of distribution
devices are formed in the enclosure, the plurality of distribution
devices configured to apply a fluid entering the distributor onto
the tube bundle. The enclosure is formed of unitary
construction.
Inventors: |
DE LARMINAT; Paul; (Nantes,
FR) ; SCHREIBER; Jeb; (Emigsville, PA) ;
KULANKARA; Satheesh; (York, PA) |
Assignee: |
JOHNSON CONTROLS TECHNOLOGY
COMPANY
Holland
MI
|
Family ID: |
44624943 |
Appl. No.: |
12/875748 |
Filed: |
September 3, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61240435 |
Sep 8, 2009 |
|
|
|
Current U.S.
Class: |
165/160 |
Current CPC
Class: |
F25B 2339/0242 20130101;
F25B 39/028 20130101; F28F 9/0273 20130101; F28D 3/02 20130101;
F28D 2021/0071 20130101; F28D 21/0017 20130101; F28D 3/04 20130101;
F28D 7/16 20130101; F28F 9/005 20130101 |
Class at
Publication: |
165/160 |
International
Class: |
F28D 7/00 20060101
F28D007/00 |
Claims
1. A distributor for use in a vapor compression system comprising:
an enclosure configured to be positioned in a heat exchanger having
a tube bundle comprising a plurality of tubes extending
substantially horizontally in the heat exchanger; a plurality of
distribution devices formed in the enclosure, the plurality of
distribution devices configured to apply a fluid entering the
distributor onto the tube bundle; wherein the enclosure is formed
of unitary construction.
2. The distributor of claim 1, wherein the plurality of
distribution devices comprises at least one opening formed by a
group consisting of a cutting tool having a rotating blade, a
cutting tool having a reciprocating blade and a press.
3. The distributor of claim 2, wherein the at least one opening
defines one of a V-shaped notch or resembling a notch formed by a
vertical rounded end mill.
4. The distributor of claim 1, wherein the plurality of
distribution devices are arranged in an organized pattern.
5. The distributor of claim 1, wherein the plurality of
distribution devices are arranged in a scattered pattern.
6. The distributor of claim 5, wherein the scattered pattern is a
random pattern.
7. The distributor of claim 2, wherein the at least one opening is
formed at an angle to a length of the enclosure.
8. The distributor of claim 7, wherein the angle is parallel to the
length of the enclosure.
9. The distributor of claim 7, wherein the angle is perpendicular
to the length of the enclosure.
10. The distributor of claim 2, wherein the at least one opening is
formed at an angle to a surface of the enclosure.
11. The distributor of claim 10, wherein at least one portion of
one side of the at least one opening is formed at an angle between
zero and ninety degrees to a surface of the enclosure.
12. The distributor of claim 2, wherein the enclosure includes at
least one corner, with at least one opening formed in or near the
at least one corner.
13. A heat exchanger for use in a vapor compression system
comprising: a shell; a tube bundle; a hood; a distributor; the tube
bundle comprising a plurality of tubes extending substantially
horizontally in the shell; the hood covers and substantially
laterally surrounds the tube bundle; the distributor comprises an
enclosure configured to be positioned in the heat exchanger; and a
plurality of distribution devices formed in the enclosure, the
plurality of distribution devices configured to apply a fluid
entering the distributor onto the tube bundle; wherein the
enclosure is formed of unitary construction.
14. The heat exchanger of claim 13, wherein the plurality of
distribution devices comprises at least one opening formed by a
group consisting of a cutting tool having a rotating blade, a
cutting tool having a reciprocating blade and a press.
15. The distributor of claim 13, wherein the plurality of
distribution devices are arranged in an organized pattern.
16. The distributor of claim 13, wherein the plurality of
distribution devices are arranged in a scattered pattern.
17. The distributor of claim 14, wherein the at least one opening
is formed at an angle to a length of the enclosure.
18. The distributor of claim 17, wherein the angle is parallel to
the length of the enclosure.
19. The distributor of claim 17, wherein the angle is perpendicular
to the length of the enclosure.
20. The distributor of claim 13, wherein the at least one opening
is formed at an angle to a surface of the enclosure.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from and the benefit of
U.S. Provisional Application No. 61/240,435, entitled VAPOR
COMPRESSION SYSTEM, filed Sep. 8, 2009, which is hereby
incorporated by reference.
BACKGROUND
[0002] The application relates generally to vapor compression
systems in refrigeration, air conditioning and chilled liquid
systems. The application relates more specifically to distribution
systems and methods in vapor compression systems.
[0003] Conventional chilled liquid systems used in heating,
ventilation and air conditioning systems include an evaporator to
effect a transfer of thermal energy between the refrigerant of the
system and another liquid to be cooled. One type of evaporator
includes a shell with a plurality of tubes forming a tube bundle(s)
through which the liquid to be cooled is circulated. The
refrigerant is brought into contact with the outer or exterior
surfaces of the tube bundle inside the shell, resulting in a
transfer of thermal energy between the liquid to be cooled and the
refrigerant. For example, refrigerant can be deposited onto the
exterior surfaces of the tube bundle by spraying or other similar
techniques in what is commonly referred to as a "falling film"
evaporator. In a further example, the exterior surfaces of the tube
bundle can be fully or partially immersed in liquid refrigerant in
what is commonly referred to as a "flooded" evaporator. In yet
another example, a portion of the tube bundle can have refrigerant
deposited on the exterior surfaces and another portion of the tube
bundle can be immersed in liquid refrigerant in what is commonly
referred to as a "hybrid falling film" evaporator.
[0004] As a result of the thermal energy transfer with the liquid,
the refrigerant is heated and converted to a vapor state, which is
then returned to a compressor where the vapor is compressed, to
begin another refrigerant cycle. The cooled liquid can be
circulated to a plurality of heat exchangers located throughout a
building. Warmer air from the building is passed over the heat
exchangers where the cooled liquid is warmed, while cooling the air
for the building. The liquid warmed by the building air is returned
to the evaporator to repeat the process.
SUMMARY
[0005] The present invention relates to a distributor for use in a
vapor compression system including an enclosure configured to be
positioned in a heat exchanger having a tube bundle comprising a
plurality of tubes extending substantially horizontally in the heat
exchanger. A plurality of distribution devices are formed in the
enclosure, the plurality of distribution devices configured to
apply a fluid entering the distributor onto the tube bundle. The
enclosure is formed of unitary construction.
[0006] The present invention further relates to a heat exchanger
for use in a vapor compression system including a shell, a tube
bundle, a hood, and a distributor. The tube bundle includes a
plurality of tubes extending substantially horizontally in the
shell. The hood covers and substantially laterally surrounds the
tube bundle. The distributor includes an enclosure configured to be
positioned in the heat exchanger. A plurality of distribution
devices are formed in the enclosure. The plurality of distribution
devices is configured to apply a fluid entering the distributor
onto the tube bundle. The enclosure is formed of unitary
construction.
BRIEF DESCRIPTION OF THE FIGURES
[0007] FIG. 1 shows an exemplary embodiment for a heating,
ventilation and air conditioning system.
[0008] FIG. 2 shows an isometric view of an exemplary vapor
compression system.
[0009] FIGS. 3 and 4 schematically illustrate exemplary embodiments
of the vapor compression system.
[0010] FIG. 5A shows an exploded, partial cutaway view of an
exemplary evaporator.
[0011] FIG. 5B shows a top isometric view of the evaporator of FIG.
5A.
[0012] FIG. 5C shows a cross section of the evaporator taken along
line 5-5 of FIG. 5B.
[0013] FIG. 6A shows a top isometric view of an exemplary
evaporator.
[0014] FIGS. 6B and 6C show a cross section of the evaporator taken
along line 6-6 of FIG. 6A.
[0015] FIG. 7 shows an exemplary embodiment of an inverted
enclosure of a distribution device.
[0016] FIG. 8 shows a cross section of the enclosure taken along
line 8-8 of FIG. 7.
[0017] FIG. 9 shows an exemplary embodiment of an inverted
enclosure of a distribution device.
[0018] FIG. 10 shows a cross section of the enclosure taken along
line 10-10 of FIG. 9.
[0019] FIG. 11 shows an exemplary embodiment of an inverted
enclosure with a distribution device.
[0020] FIG. 12 shows another exemplary embodiment of an inverted
enclosure with a distribution device.
[0021] FIG. 13 shows another exemplary embodiment of an inverted
enclosure with a distribution device.
[0022] FIG. 14 shows yet another exemplary embodiment of an
inverted enclosure with a distribution device.
[0023] FIG. 15 shows another exemplary embodiment of an inverted
enclosure with a distribution device.
[0024] FIG. 16 shows yet another exemplary embodiment of an
inverted enclosure with a distribution device.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0025] FIG. 1 shows an exemplary environment for a heating,
ventilation and air conditioning (HVAC) system 10 incorporating a
chilled liquid system in a building 12 for a typical commercial
setting. System 10 can include a vapor compression system 14 that
can supply a chilled liquid which may be used to cool building 12.
System 10 can include a boiler 16 to supply heated liquid that may
be used to heat building 12, and an air distribution system which
circulates air through building 12. The air distribution system can
also include an air return duct 18, an air supply duct 20 and an
air handler 22. Air handler 22 can include a heat exchanger that is
connected to boiler 16 and vapor compression system 14 by conduits
24. The heat exchanger in air handler 22 may receive either heated
liquid from boiler 16 or chilled liquid from vapor compression
system 14, depending on the mode of operation of system 10. System
10 is shown with a separate air handler on each floor of building
12, but it is appreciated that the components may be shared between
or among floors.
[0026] FIGS. 2 and 3 show an exemplary vapor compression system 14
that can be used in an HVAC system, such as HVAC system 10. Vapor
compression system 14 can circulate a refrigerant through a
compressor 32 driven by a motor 50, a condenser 34, expansion
device(s) 36, and a liquid chiller or evaporator 38. Vapor
compression system 14 can also include a control panel 40 that can
include an analog to digital (ND) converter 42, a microprocessor
44, a non-volatile memory 46, and an interface board 48. Some
examples of fluids that may be used as refrigerants in vapor
compression system 14 are hydrofluorocarbon (HFC) based
refrigerants, for example, R-410A, R-407, R-134a, hydrofluoro
olefin (HFO), "natural" refrigerants like ammonia (NH3), R-717,
carbon dioxide (CO2), R-744, or hydrocarbon based refrigerants,
water vapor or any other suitable type of refrigerant. In an
exemplary embodiment, vapor compression system 14 may use one or
more of each of VSDs 52, motors 50, compressors 32, condensers 34
and/or evaporators 38.
[0027] Motor 50 used with compressor 32 can be powered by a
variable speed drive (VSD) 52 or can be powered directly from an
alternating current (AC) or direct current (DC) power source. VSD
52, if used, receives AC power having a particular fixed line
voltage and fixed line frequency from the AC power source and
provides power having a variable voltage and frequency to motor 50.
Motor 50 can include any type of electric motor that can be powered
by a VSD or directly from an AC or DC power source. For example,
motor 50 can be a switched reluctance motor, an induction motor, an
electronically commutated permanent magnet motor or any other
suitable motor type. In an alternate exemplary embodiment, other
drive mechanisms such as steam or gas turbines or engines and
associated components can be used to drive compressor 32.
[0028] Compressor 32 compresses a refrigerant vapor and delivers
the vapor to condenser 34 through a discharge line. Compressor 32
can be a centrifugal compressor, screw compressor, reciprocating
compressor, rotary compressor, swing link compressor, scroll
compressor, turbine compressor, or any other suitable compressor.
The refrigerant vapor delivered by compressor 32 to condenser 34
transfers heat to a fluid, for example, water or air. The
refrigerant vapor condenses to a refrigerant liquid in condenser 34
as a result of the heat transfer with the fluid. The liquid
refrigerant from condenser 34 flows through expansion device 36 to
evaporator 38. In the exemplary embodiment shown in FIG. 3,
condenser 34 is water cooled and includes a tube bundle 54
connected to a cooling tower 56.
[0029] The liquid refrigerant delivered to evaporator 38 absorbs
heat from another fluid, which may or may not be the same type of
fluid used for condenser 34, and undergoes a phase change to a
refrigerant vapor. In the exemplary embodiment shown in FIG. 3,
evaporator 38 includes a tube bundle having a supply line 60S and a
return line 60R connected to a cooling load 62. A process fluid,
for example, water, ethylene glycol, calcium chloride brine, sodium
chloride brine, or any other suitable liquid, enters evaporator 38
via return line 60R and exits evaporator 38 via supply line 60S.
Evaporator 38 chills the temperature of the process fluid in the
tubes. The tube bundle in evaporator 38 can include a plurality of
tubes and a plurality of tube bundles. The vapor refrigerant exits
evaporator 38 and returns to compressor 32 by a suction line to
complete the cycle.
[0030] FIG. 4, which is similar to FIG. 3, shows the refrigerant
circuit with an intermediate circuit 64 that may be incorporated
between condenser 34 and expansion device 36 to provide increased
cooling capacity, efficiency and performance. Intermediate circuit
64 has an inlet line 68 that can be either connected directly to or
can be in fluid communication with condenser 34. As shown, inlet
line 68 includes an expansion device 66 positioned upstream of an
intermediate vessel 70. Intermediate vessel 70 can be a flash tank,
also referred to as a flash intercooler, in an exemplary
embodiment. In an alternate exemplary embodiment, intermediate
vessel 70 can be configured as a heat exchanger or a "surface
economizer." In the flash intercooler arrangement, a first
expansion device 66 operates to lower the pressure of the liquid
received from condenser 34. During the expansion process in a flash
intercooler, a portion of the liquid is evaporated. Intermediate
vessel 70 may be used to separate the evaporated vapor from the
liquid received from the condenser. The evaporated liquid may be
drawn by compressor 32 to a port at a pressure intermediate between
suction and discharge or at an intermediate stage of compression,
through a line 74. The liquid that is not evaporated is cooled by
the expansion process, and collects at the bottom of intermediate
vessel 70, where the liquid is recovered to flow to the evaporator
38, through a line 72 comprising a second expansion device 36.
[0031] In the "surface intercooler" arrangement, the implementation
is slightly different, as known to those skilled in the art.
Intermediate circuit 64 can operate in a similar matter to that
described above, except that instead of receiving the entire amount
of refrigerant from condenser 34, as shown in FIG. 4, intermediate
circuit 64 receives only a portion of the refrigerant from
condenser 34 and the remaining refrigerant proceeds directly to
expansion device 36.
[0032] FIGS. 5A-5C show an exemplary embodiment of an evaporator
configured as a "hybrid falling film" evaporator. As shown in FIGS.
5A-5C, an evaporator 138 includes a substantially cylindrical shell
76 with a plurality of tubes forming a tube bundle 78 extending
substantially horizontally along the length of shell 76. At least
one support 116 may be positioned inside shell 76 to support the
plurality of tubes in tube bundle 78. A suitable fluid, such as
water, ethylene, ethylene glycol, or calcium chloride brine flows
through the tubes of tube bundle 78. A distributor 80 positioned
above tube bundle 78 distributes, deposits or applies refrigerant
110 from a plurality of positions onto the tubes in tube bundle 78.
In one exemplary embodiment, the refrigerant deposited by
distributor 80 can be entirely liquid refrigerant, although in
another exemplary embodiment, the refrigerant deposited by
distributor 80 can include both liquid refrigerant and vapor
refrigerant.
[0033] Liquid refrigerant that flows around the tubes of tube
bundle 78 without changing state collects in the lower portion of
shell 76. The collected liquid refrigerant can form a pool or
reservoir of liquid refrigerant 82. The deposition positions from
distributor 80 can include any combination of longitudinal or
lateral positions with respect to tube bundle 78. In another
exemplary embodiment, deposition positions from distributor 80 are
not limited to ones that deposit onto the upper tubes of tube
bundle 78. Distributor 80 may include a plurality of nozzles
supplied by a dispersion source of the refrigerant. In an exemplary
embodiment, the dispersion source is a tube connecting a source of
refrigerant, such as condenser 34. Nozzles include spraying
nozzles, but also include machined openings that can guide or
direct refrigerant onto the surfaces of the tubes. The nozzles may
apply refrigerant in a predetermined pattern, such as a jet
pattern, so that the upper row of tubes of tube bundle 78 are
covered. The tubes of tube bundle 78 can be arranged to promote the
flow of refrigerant in the form of a film around the tube surfaces,
the liquid refrigerant coalescing to form droplets or in some
instances, a curtain or sheet of liquid refrigerant at the bottom
of the tube surfaces. The resulting sheeting promotes wetting of
the tube surfaces which enhances the heat transfer efficiency
between the fluid flowing inside the tubes of tube bundle 78 and
the refrigerant flowing around the surfaces of the tubes of tube
bundle 78.
[0034] In the pool of liquid refrigerant 82, a tube bundle 140 can
be immersed or at least partially immersed, to provide additional
thermal energy transfer between the refrigerant and the process
fluid to evaporate the pool of liquid refrigerant 82. In an
exemplary embodiment, tube bundle 78 can be positioned at least
partially above (that is, at least partially overlying) tube bundle
140. In one exemplary embodiment, evaporator 138 incorporates a two
pass system, in which the process fluid that is to be cooled first
flows inside the tubes of tube bundle 140 and then is directed to
flow inside the tubes of tube bundle 78 in the opposite direction
to the flow in tube bundle 140. In the second pass of the two pass
system, the temperature of the fluid flowing in tube bundle 78 is
reduced, thus requiring a lesser amount of heat transfer with the
refrigerant flowing over the surfaces of tube bundle 78 to obtain a
desired temperature of the process fluid.
[0035] It is to be understood that although a two pass system is
described in which the first pass is associated with tube bundle
140 and the second pass is associated with tube bundle 78, other
arrangements are contemplated. For example, evaporator 138 can
incorporate a one pass system where the process fluid flows through
both tube bundle 140 and tube bundle 78 in the same direction.
Alternatively, evaporator 138 can incorporate a three pass system
in which two passes are associated with tube bundle 140 and the
remaining pass associated with tube bundle 78, or in which one pass
is associated with tube bundle 140 and the remaining two passes are
associated with tube bundle 78. Further, evaporator 138 can
incorporate an alternate two pass system in which one pass is
associated with both tube bundle 78 and tube bundle 140, and the
second pass is associated with both tube bundle 78 and tube bundle
140. In one exemplary embodiment, tube bundle 78 is positioned at
least partially above tube bundle 140, with a gap separating tube
bundle 78 from tube bundle 140. In a further exemplary embodiment,
hood 86 overlies tube bundle 78, with hood 86 extending toward and
terminating near the gap. In summary, any number of passes in which
each pass can be associated with one or both of tube bundle 78 and
tube bundle 140 is contemplated.
[0036] An enclosure or hood 86 is positioned over tube bundle 78 to
substantially prevent cross flow, that is, a lateral flow of vapor
refrigerant or liquid and vapor refrigerant 106 between the tubes
of tube bundle 78. Hood 86 is positioned over and laterally borders
tubes of tube bundle 78. Hood 86 includes an upper end 88
positioned near the upper portion of shell 76. Distributor 80 can
be positioned between hood 86 and tube bundle 78. In yet a further
exemplary embodiment, distributor 80 may be positioned near, but
exterior of, hood 86, so that distributor 80 is not positioned
between hood 86 and tube bundle 78. However, even though
distributor 80 is not positioned between hood 86 and tube bundle
78, the nozzles of distributor 80 are still configured to direct or
apply refrigerant onto surfaces of the tubes. Upper end 88 of hood
86 is configured to substantially prevent the flow of applied
refrigerant 110 and partially evaporated refrigerant, that is,
liquid and/or vapor refrigerant 106 from flowing directly to outlet
104. Instead, applied refrigerant 110 and refrigerant 106 are
constrained by hood 86, and, more specifically, are forced to
travel downward between walls 92 before the refrigerant can exit
through an open end 94 in the hood 86. Flow of vapor refrigerant 96
around hood 86 also includes evaporated refrigerant flowing away
from the pool of liquid refrigerant 82.
[0037] It is to be understood that at least the above-identified,
relative terms are non-limiting as to other exemplary embodiments
in the disclosure. For example, hood 86 may be rotated with respect
to the other evaporator components previously discussed, that is,
hood 86, including walls 92, is not limited to a vertical
orientation. Upon sufficient rotation of hood 86 about an axis
substantially parallel to the tubes of tube bundle 78, hood 86 may
no longer be considered "positioned over" nor to "laterally border"
tubes of tube bundle 78. Similarly, "upper" end 88 of hood 86 may
no longer be near "an upper portion" of shell 76, and other
exemplary embodiments are not limited to such an arrangement
between the hood and the shell. In an exemplary embodiment, hood 86
terminates after covering tube bundle 78, although in another
exemplary embodiment, hood 86 further extends after covering tube
bundle 78.
[0038] After hood 86 forces refrigerant 106 downward between walls
92 and through open end 94, the vapor refrigerant undergoes an
abrupt change in direction before traveling in the space between
shell 76 and walls 92 from the lower portion of shell 76 to the
upper portion of shell 76. Combined with the effect of gravity, the
abrupt directional change in flow results in a proportion of any
entrained droplets of refrigerant colliding with either liquid
refrigerant 82 or shell 76, thereby removing those droplets from
the flow of vapor refrigerant 96. Also, refrigerant mist traveling
along the length of hood 86 between walls 92 is coalesced into
larger drops that are more easily separated by gravity, or
maintained sufficiently near or in contact with tube bundle 78, to
permit evaporation of the refrigerant mist by heat transfer with
the tube bundle. As a result of the increased drop size, the
efficiency of liquid separation by gravity is improved, permitting
an increased upward velocity of vapor refrigerant 96 flowing
through the evaporator in the space between walls 92 and shell 76.
Vapor refrigerant 96, whether flowing from open end 94 or from the
pool of liquid refrigerant 82, flows over a pair of extensions 98
protruding from walls 92 near upper end 88 and into a channel 100.
Vapor refrigerant 96 enters into channel 100 through slots 102,
which is the space between the ends of extensions 98 and shell 76,
before exiting evaporator 138 at an outlet 104. In another
exemplary embodiment, vapor refrigerant 96 can enter into channel
100 through openings or apertures formed in extensions 98, instead
of slots 102. In yet another exemplary embodiment, slots 102 can be
formed by the space between hood 86 and shell 76, that is, hood 86
does not include extensions 98.
[0039] Stated another way, once refrigerant 106 exits from hood 86,
vapor refrigerant 96 then flows from the lower portion of shell 76
to the upper portion of shell 76 along the prescribed passageway.
In an exemplary embodiment, the passageways can be substantially
symmetric between the surfaces of hood 86 and shell 76 prior to
reaching outlet 104. In an exemplary embodiment, baffles, such as
extensions 98 are provided near the evaporator outlet to prevent a
direct path of vapor refrigerant 96 to the compressor inlet.
[0040] In one exemplary embodiment, hood 86 includes opposed
substantially parallel walls 92. In another exemplary embodiment,
walls 92 can extend substantially vertically and terminate at open
end 94, that is located substantially opposite upper end 88. Upper
end 88 and walls 92 are closely positioned near the tubes of tube
bundle 78, with walls 92 extending toward the lower portion of
shell 76 so as to substantially laterally border the tubes of tube
bundle 78. In an exemplary embodiment, walls 92 may be spaced
between about 0.02 inch (0.5 mm) and about 0.8 inch (20 mm) from
the tubes in tube bundle 78. In a further exemplary embodiment,
walls 92 may be spaced between about 0.1 inch (3 mm) and about 0.2
inch (5 mm) from the tubes in tube bundle 78. However, spacing
between upper end 88 and the tubes of tube bundle 78 may be
significantly greater than 0.2 inch (5 mm), in order to provide
sufficient spacing to position distributor 80 between the tubes and
the upper end of the hood. In an exemplary embodiment in which
walls 92 of hood 86 are substantially parallel and shell 76 is
cylindrical, walls 92 may also be symmetric about a central
vertical plane of symmetry of the shell bisecting the space
separating walls 92. In other exemplary embodiments, walls 92 need
not extend vertically past the lower tubes of tube bundle 78, nor
do walls 92 need to be planar, as walls 92 may be curved or have
other non-planar shapes. Regardless of the specific construction,
hood 86 is configured to channel refrigerant 106 within the
confines of walls 92 through open end 94 of hood 86.
[0041] FIGS. 6A-6C show an exemplary embodiment of an evaporator
configured as a "falling film" evaporator 128. As shown in FIGS.
6A-6C, evaporator 128 is similar to evaporator 138 shown in FIGS.
5A-5C, except that evaporator 128 does not include tube bundle 140
in the pool of refrigerant 82 that collects in the lower portion of
the shell. In an exemplary embodiment, hood 86 terminates after
covering tube bundle 78, although in another exemplary embodiment,
hood 86 further extends toward pool of refrigerant 82 after
covering tube bundle 78. In yet a further exemplary embodiment,
hood 86 terminates so that the hood does not totally cover the tube
bundle, that is, substantially covers the tube bundle.
[0042] As shown in FIGS. 6B and 6C, a pump 84 can be used to
recirculate the pool of liquid refrigerant 82 from the lower
portion of the shell 76 via line 114 to distributor 80. As further
shown in FIG. 6B, line 114 can include a regulating device 112 that
can be in fluid communication with a condenser (not shown). In
another exemplary embodiment, an ejector (not shown) can be
employed to draw liquid refrigerant 82 from the lower portion of
shell 76 using the pressurized refrigerant from condenser 34, which
operates by virtue of the Bernoulli effect. The ejector combines
the functions of a regulating device 112 and a pump 84.
[0043] In an exemplary embodiment, one arrangement of tubes or tube
bundles may be defined by a plurality of uniformly spaced tubes
that are aligned vertically and horizontally, forming an outline
that can be substantially rectangular. However, a stacking
arrangement of tube bundles can be used where the tubes are neither
vertically or horizontally aligned, as well as arrangements that
are not uniformly spaced.
[0044] In another exemplary embodiment, different tube bundle
constructions are contemplated. For example, finned tubes (not
shown) can be used in a tube bundle, such as along the uppermost
horizontal row or uppermost portion of the tube bundle. Besides the
possibility of using finned tubes, tubes developed for more
efficient operation for pool boiling applications, such as in
"flooded" evaporators, may also be employed. Additionally, or in
combination with the finned tubes, porous coatings can also be
applied to the outer surface of the tubes of the tube bundles.
[0045] In a further exemplary embodiment, the cross-sectional
profile of the evaporator shell may be non-circular.
[0046] In an exemplary embodiment, a portion of the hood may
partially extend into the shell outlet.
[0047] In addition, it is possible to incorporate the expansion
functionality of the expansion devices of system 14 into
distributor 80. In one exemplary embodiment, two expansion devices
may be employed. One expansion device is exhibited in the spraying
nozzles of distributor 80. The other expansion device, for example,
expansion device 36, can provide a preliminary partial expansion of
refrigerant, before that provided by the spraying nozzles
positioned inside the evaporator. In an exemplary embodiment, the
other expansion device, that is, the non-spraying nozzle expansion
device, can be controlled by the level of liquid refrigerant 82 in
the evaporator to account for variations in operating conditions,
such as evaporating and condensing pressures, as well as partial
cooling loads. In an alternative exemplary embodiment, expansion
device can be controlled by the level of liquid refrigerant in the
condenser, or in a further exemplary embodiment, a "flash
economizer" vessel. In one exemplary embodiment, the majority of
the expansion can occur in the nozzles, providing a greater
pressure difference, while simultaneously permitting the nozzles to
be of reduced size, therefore reducing the size and cost of the
nozzles.
[0048] FIGS. 7-16 show respective enclosures or housings 148, 150,
152, 154, 156, 158, 160, 162 for a distributor. For simplicity, the
term "the enclosures" may refer at least to any of the exemplary
embodiments shown in FIGS. 7-16 or described in the present
disclosure. The enclosures can have a predetermined shape, such as,
but not limited to, a rectangular, diamond, circular, cylindrical
and/or square shape for improving refrigerant flow to tube bundle
78. Any suitable shape may be used for the enclosures, so long as
refrigerant flow 106 can be maintained through the enclosure.
Inlets (not shown) may be located at an upper portion of enclosure
or at the ends of enclosure. Distribution devices 130, such as
nozzles, holes, or openings, including slotted openings sometimes
referred to as slits, can be formed or located on a bottom portion,
side portion, or other suitable location of the enclosure to allow
refrigerant 110 to flow onto tube bundles 78. Distribution devices
130 may also be formed or located close together, if multiple
distribution devices 130 are formed or located in the enclosure.
Distribution devices 130 may be arranged in a strategic organized
pattern or distribution devices 130 may be arranged in a varying or
scattered pattern along the enclosure. In one embodiment, a
scattered pattern of distribution devices 130 includes a random
pattern of distribution devices.
[0049] Distribution devices 130 may be formed at an angle in
relation to the sides of the enclosure, such as a V-shaped notch
formed in a flat surface, in which the V-shaped notch may be
oriented perpendicular to the surface. In one embodiment, the
V-shaped notch may be formed in a flat surface in which the
centerline of the notch is not oriented perpendicular to the
surface. Alternately, for shapes having arguably one continuous
surface, such as a circular shape, such as a circular cylinder, the
V-shaped notch may be radially oriented in the circular shape, in
which the center line of the V-shaped notch may extend in a
direction that is parallel to a line directed through the center
axis of the cylinder, although in other embodiments, the centerline
of the V-shaped notch may not align with the center axis. In a
further alternate arrangement, the V-shaped notch may be oriented
in a direction that is perpendicular to the center axis of the
cylinder, such as shown in FIG. 11. It is to be understood that in
a further embodiment, the V-shaped notch may be oriented in a
direction that is between a radially oriented position and a
perpendicularly oriented position with respect to the center axis
of the cylinder, or the sides of enclosure that is non-circular or
non-cylindrical. It is to be understood that notches may define
profiles that are not V-shaped.
[0050] As shown in FIGS. 7-8, distribution devices 130 may be
arranged substantially perpendicular to the length of enclosure
148. In one embodiment, distribution devices 130 may be formed by a
blade of a cutting tool, such as a cutting tool having a rotating
blade, in which the orientation of the distribution device
(openings formed by the cutting tool) may be aligned with a linear
arrangement of openings formed in the enclosure. However, in
another embodiment, distribution devices 130 may be arranged in
substantial alignment with respect to the length of the enclosure.
In a further embodiment (not shown), distribution devices 130 may
be positioned in a non-linear arrangement, and in yet another
embodiment (not shown), in addition to distribution devices 130
being positioned in a nonlinear arrangement, the shape of the
enclosure may extend nonlinearly, such as a curve.
[0051] The enclosures shown in FIGS. 7-16 may contain a variety of
distribution devices 130, if desired, to provide refrigerant flow
to tube bundle 78. The enclosure may include at least one
distribution device 130 that is a nozzle, at least one distribution
device 130 that is formed in the enclosure, at least one
distribution device 130 being arranged in a strategic pattern with
another distribution device 130, another distribution device 130
being arranged in a varying pattern or non-pattern with another
distribution device 130 and/or another distribution device 130 that
is formed or disposed at an angle in relation to another
distribution device 130 or in relation to the sides of enclosure,
and any combination thereof. In other words, distribution devices
130 can be located and formed in enclosure in such a manner to
provide a uniform distribution of applied refrigerant 110 to tube
bundles 78, even if the arrangement of distribution devices 130
includes a variety of nozzles, formations, and patterns on the
enclosure. A uniform distribution of applied refrigerant 110 on
tube bundles 78 provides improved heat transfer and cooling to tube
bundles 78.
[0052] Relative spacial terms such as upper, lower, horizontal,
inverted and the like, are not intended to be limiting, but are
provided to assist with providing an understanding of the
disclosure.
[0053] Other exemplary embodiments of the enclosures may include
openings (not shown) in the upper portion of the enclosure to allow
for the flow of vapor refrigerant from the enclosure. In an
exemplary embodiment, distribution devices 130 may be formed by a
cutting tool, such as a cutting tool with a rotating blade or
reciprocating blade, or may be formed by other methods, such as a
press. For example, an axial internal hole or opening may be
drilled in the enclosure using a drill bit or other device with a
rounded or tapered end. From the outside of the enclosure, the
rounded or tapered end of the internal hole may be intersected with
a notch that has a V-shape. In a further exemplary embodiment,
distribution devices 130 may be formed in the enclosure prior to
the enclosure being formed into a final shape. In each of these
distribution device embodiments, the enclosure is formed of unitary
construction. That is, such as in these embodiments, the enclosure
contains a single part.
[0054] Referring specifically to FIGS. 7 and 8, enclosure 148 is
shown in an inverted position, having a diamond shaped
cross-section. FIGS. 9 and 10 show enclosure 150 in an inverted
position, having an irregular hexagon shaped cross section. The
irregular hexagon cross section shape may be similar to a
rectangular shape, having the bottom corners angled, forming a
hexagon, rather than a rectangle, as shown in FIG. 10. Enclosures
148 and 150 are located above tube bundles (not shown) such that
refrigerant 110 can be applied to tube bundles 78 to provide heat
transfer to tube bundles (not shown). When located above tube
bundles 78, distribution devices 130 may be positioned on the
bottom surface, or in other words, distribution devices 130 provide
a flow path for refrigerant 106 such that refrigerant 106 flows
from enclosures 148 and 150 downward onto tube bundles.
Distribution devices 130 are shown as being formed in enclosures
148 and 150. Distribution devices 130 may be a separate device such
as a nozzle and placed in enclosures 148 and 150 during or after
manufacture of enclosures 148 and 150. Distribution devices 130 are
shown as having substantially parallel walls to provide a flow path
for refrigerant 106. Distribution devices 130 may have non-parallel
walls, or any other suitable shape for providing a flow path for
refrigerant 106 from enclosures 148 and 150 are to tube bundles 78.
In a further embodiment, the enclosure may extend nonlinearly.
FIGS. 7, 8, 9, and 10 show three sets of distribution devices 130
formed on each bottom surface 144 of enclosure 148 and enclosure
150, however any suitable number of distribution devices 130 may be
formed or located in enclosures 148 and 150 to provide a flow path
for refrigerant 106 to tube bundles 78. For example, enclosure 150
may include distribution devices 130 formed along the bottom
corners of enclosure 150. Enclosures 148 and 150 may also include
openings (not shown) on the top surface or surfaces 146 to provide
ventilation of vapor refrigerant from enclosures 148 and 150.
[0055] Referring specifically to FIG. 11, enclosure 152 is shown in
an inverted position. FIG. 11 shows enclosure 152 having a
cylindrical shape with a circular cross section, however enclosure
152 may have any suitable shape, with any suitable cross section,
such as the shape and cross section of any other embodiment
disclosed herein. Enclosure 152 is located above tube bundles (not
shown) such that refrigerant 110 can be applied to tube bundles 78
to provide heat transfer to tube bundles (not shown). When located
above tube bundles 78, distribution device(s) may be positioned on
the bottom surface, or in other words, distribution devices 130
provide a flow path for refrigerant 106 such that refrigerant 106
flows from enclosure 152 downward onto tube bundles 78.
Distribution devices 130 may be located on any suitable location on
enclosure 152, for example, the side surfaces. Alternately, for
shapes having arguably one continuous surface, such as a circular
shape, distribution devices 130 may be positioned at different
locations along the periphery of the enclosure. Refrigerant 106
flows through enclosure 152, and at least a portion of refrigerant
106 passes through distribution devices 130 and onto tube bundles
78.
[0056] Distribution devices 130 are shown as being formed in
enclosure 152, however distribution devices 130 may be a separate
device such as a nozzle, and placed in enclosure 152 during or
after manufacture. Distribution devices 130 are shown as having
been formed with a V-shaped cut or V-notch, or vertical rounded end
mill cut or notch, however distribution devices 130 may have any
other suitable shape for providing a flow path for refrigerant 106
from enclosure 130 to tube bundles 78, such as the distribution
devices shown in FIGS. 12 and 13. FIG. 12 shows a distribution
device 130 having being formed with a horizontal V-shaped cut or
V-notch in enclosure 154 with a narrower opening than distribution
device 130 shown in FIG. 11. Referring specifically to FIG. 13,
enclosure 156 is shown having a distribution device 130 having been
formed with a horizontal saw cut with substantially parallel sides.
Enclosures 152, 154, and 156 shown in FIGS. 11, 12 and 13 may have
any other suitably shaped formation of distribution devices 130 to
provide a flow path for refrigerant 106 from enclosures 152, 154,
and 156 to tube bundles 78.
[0057] Referring specifically to FIG. 14, FIG. 14 shows an inverted
enclosure 158 similar to the enclosures 152, 154, and 156 shown in
FIGS. 11, 12, and 13. However, FIG. 14 shows enclosure 158 having a
rectangular or square shaped cross section. Enclosure 158 may have
any suitable shape with any suitable cross section, such as the
shape and cross section of any other embodiment disclosed herein.
FIG. 14 shows a distribution device 130 formed with a V-shaped cut
or V-notch on each of the lower corners of the square, although
distribution devices 130 may have substantially parallel walls, as
shown as formed in enclosure 160 in FIG. 15. Enclosures 158 and 160
shown in FIGS. 14 and 15 may have any other suitably shaped
formation of distribution devices 130 to provide a flow path for
refrigerant 106 from enclosures 158 and 160 to tube bundles 78.
Distribution devices 130 may also be formed or located on other
areas of enclosures 158 and 160 and not on only the lower corners
as shown in FIGS. 14 and 15.
[0058] Referring specifically to FIG. 16, enclosure 162 is similar
to enclosures shown in FIGS. 7, 11, 12, 13, 14, and 15. Enclosure
162 is in an inverted position having a diamond shaped cross
section. Distribution devices are shown as being formed in
enclosure 162 on the bottom angle surface of the diamond shape, or
in other words, distribution devices 130 provide a flow path for
refrigerant 106 such that refrigerant 106 flows from enclosure 162
downward onto tube bundles 78. Distribution devices 130 may also be
located on any suitable location on enclosure 162, for example, the
sides. Refrigerant 106 flows through enclosure 162, and at least a
portion of refrigerant 106 passes through distribution devices 130
and onto tube bundles 78. Distribution devices 130 are shown as
being formed in enclosure 162, however, distribution devices 130
may be a separate device such as a nozzle, and placed in enclosure
162. Distribution devices 130 are shown as having being formed with
a horizontal V-shaped cut or V-notch, however distribution devices
130 may have substantially parallel walls or any other suitable
shaped formation to provide a flow path for refrigerant 106 from
enclosure 162 to tube bundles 78. FIG. 16 may include any number of
distribution devices 130 formed in enclosure 162 to provide a flow
path for refrigerant 106 to tube bundles 78.
[0059] Although distribution devices 130 may be formed at
substantially forty five degrees to a horizontal axis of the
enclosures, distribution devices 130 may be formed at any angle
other than forty five degrees to the horizontal axis to provide
liquid distribution to tube bundles. Stated another way, one side
of the distribution device may be formed at any angle between zero
and ninety degrees to a surface of the enclosure or with respect to
the direction (or length) of the enclosure.
[0060] While only certain features and embodiments of the invention
have been shown and described, many modifications and changes may
occur to those skilled in the art (e.g., variations in sizes,
dimensions, structures, shapes and proportions of the various
elements, values of parameters (e.g., temperatures, pressures,
etc.), mounting arrangements, use of materials, colors,
orientations, etc.) without materially departing from the novel
teachings and advantages of the subject matter recited in the
claims. The order or sequence of any process or method steps may be
varied or re-sequenced according to alternative embodiments. It is,
therefore, to be understood that the appended claims are intended
to cover all such modifications and changes as fall within the true
spirit of the invention. Furthermore, in an effort to provide a
concise description of the exemplary embodiments, all features of
an actual implementation may not have been described (i.e., those
unrelated to the presently contemplated best mode of carrying out
the invention, or those unrelated to enabling the claimed
invention). It should be appreciated that in the development of any
such actual implementation, as in any engineering or design
project, numerous implementation-specific decisions may be made.
Such a development effort might be complex and time consuming, but
would nevertheless be a routine undertaking of design, fabrication,
and manufacture for those of ordinary skill having the benefit of
this disclosure, without undue experimentation.
* * * * *