U.S. patent application number 15/412529 was filed with the patent office on 2017-07-27 for baffle assembly for a heat exchanger, heat exchanger including the baffle assembly, fluid heating system including the same, and methods of manufacture thereof.
The applicant listed for this patent is FULTON GROUP N.A., INC.. Invention is credited to Alexander Thomas Frechette, Carl Nicholas Nett, Richard James Snyder, Thomas William Tighe, Keith Richard Waltz.
Application Number | 20170211895 15/412529 |
Document ID | / |
Family ID | 59359455 |
Filed Date | 2017-07-27 |
United States Patent
Application |
20170211895 |
Kind Code |
A1 |
Frechette; Alexander Thomas ;
et al. |
July 27, 2017 |
BAFFLE ASSEMBLY FOR A HEAT EXCHANGER, HEAT EXCHANGER INCLUDING THE
BAFFLE ASSEMBLY, FLUID HEATING SYSTEM INCLUDING THE SAME, AND
METHODS OF MANUFACTURE THEREOF
Abstract
A fluid heating system assembly including: a first tube sheet; a
second tube sheet opposite the first sheet; a heat exchanger tube,
which connects the first tube sheet and the second tube sheet; a
baffle such as a plate baffle and/or an annular baffle disposed
between the first tube sheet and the second tube sheet, wherein the
heat exchanger tube passes through the baffle.
Inventors: |
Frechette; Alexander Thomas;
(Mexico, NY) ; Nett; Carl Nicholas; (Sandisfield,
MA) ; Snyder; Richard James; (Mexico, NY) ;
Tighe; Thomas William; (Pulaski, NY) ; Waltz; Keith
Richard; (Sandy Creek, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FULTON GROUP N.A., INC. |
Pulaski |
NY |
US |
|
|
Family ID: |
59359455 |
Appl. No.: |
15/412529 |
Filed: |
January 23, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62281534 |
Jan 21, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F28F 9/005 20130101;
F28F 2230/00 20130101; F28F 9/22 20130101; F28F 2009/226 20130101;
F28D 7/1607 20130101; F28F 2275/06 20130101; F24H 1/145 20130101;
F28F 2275/025 20130101 |
International
Class: |
F28F 9/22 20060101
F28F009/22; F28F 9/26 20060101 F28F009/26; F28F 9/00 20060101
F28F009/00; F28D 7/16 20060101 F28D007/16 |
Claims
1. A baffle assembly comprising: a first tube sheet; a second tube
sheet opposite the first sheet; a heat exchanger tube, which
connects the first tube sheet and the second tube sheet; and one or
more baffles disposed between the first tube sheet and the second
tube sheet, wherein the heat exchanger tube sealingly passes
through the baffle; wherein the one or more baffles comprises one
or both of a plate baffle and an annular baffle.
2. The baffle assembly of claim 1, wherein the baffle comprises the
plate baffle.
3. The baffle assembly of claim 2, wherein fluid communication
between a first side and a second side of the plate baffle is
across a perimeter of the plate baffle.
4. The baffle assembly of claim 1, wherein the baffle comprises the
annular baffle.
5. The baffle assembly of claim 4, wherein fluid communication
between a first side and a second side of the annular baffle is
through the annulus of the baffle.
6. The baffle assembly of claim 1, wherein the plate baffle has a
disk shape, an elliptical shape, a lobular shape, a square shape, a
rectangular shape, a rectilinear shape, or a curvilinear shape, or
any combination thereof.
7. The baffle assembly of claim 1, wherein a maximum distance
between an outer surface of the heat exchanger tube and the baffle
is between 0 centimeters and 3 centimeters; and/or wherein the
baffle has an aspect ratio of 5 to 10,000, wherein the aspect ratio
is a largest dimension of a major surface of the baffle divided by
a thickness of the baffle.
8. The baffle assembly of claim 1, further comprising one or both
of a continuous weld, which sealingly connects the baffle to the
heat exchanger tube; and an adhesive, which adhesively and
sealingly connects the baffle to the heat exchanger tube, and
wherein the adhesive is disposed between the heat exchanger tube
and the baffle.
9. The baffle assembly of claim 1, wherein the baffle comprises a
rigid element, and a gasket disposed on a surface of the rigid
element and between the rigid element and the heat exchanger tube,
wherein the gasket seals the baffle to the heat exchanger tube
where the heat exchanger tube passes through the baffle.
10. The baffle assembly of claim 9, further comprising a retainer,
which is attached to the rigid element by a fastener, and wherein
the gasket is disposed between the rigid element and the
retainer.
11. The baffle assembly of claim 9, wherein the gasket comprises a
metal plate with a maximum thickness between 0.002 millimeters to 6
millimeters.
12. The baffle assembly of claim 1, wherein the baffle assembly
comprises a plurality of heat exchanger tubes, and wherein each
heat exchanger tube independently sealingly penetrates the
baffle.
13. The baffle assembly of claim 12, wherein the plurality of
baffles comprises 3 to 100 baffles.
14. The baffle assembly of claim 12, wherein the plurality of
baffles comprises at least one plate baffle and at least one
annular baffle.
15. The baffle assembly of claim 1, wherein a seal is formed
between the one or more baffles and the heat exchanger tube based
solely on a close proximity to each other.
16. A heat exchanger comprising: a pressure vessel; and the baffle
assembly of claim 1; wherein the baffle assembly is sealingly
disposed in the pressure vessel.
17. The heat exchanger of claim 16, wherein a maximum distance
between an inner surface of the pressure vessel and an edge surface
of the annular baffle is between 0 centimeters and 3
centimeters.
18. The heat exchanger of claim 16, wherein the baffle assembly
comprises an annular baffle, and further comprising a continuous
weld, which sealingly connects the annular baffle to the pressure
vessel and/or an adhesive, which adhesively and sealingly connects
the annular baffle to the pressure vessel, and wherein the adhesive
is disposed on the perimeter of the annular baffle.
19. The heat exchanger of claim 16; wherein a tube seal provided
between the heat exchanger tube and the baffle allows for less than
or equal to 10 vol % of a total fluid flow traversing the baffle,
to flow between them and/or wherein a vessel seal provided between
the pressure vessel and an annular baffle allows for less than or
equal to 10 vol % of a total fluid flow traversing the baffle, to
flow between them.
20. A method of producing radial flow in a heat exchanger, the
method comprising: providing a heat exchanger comprising a baffle
assembly comprising a pressure vessel shell comprising an inlet and
outlet, a baffle assembly entirely disposed in the pressure vessel
shell, the baffle assembly comprising a first tube sheet, a second
tube sheet opposite the first sheet, a heat exchanger tube, which
connects the first tube sheet and the second tube sheet; and at
least one plate baffle disposed between the first tube sheet and
the second tube sheet, wherein the heat exchanger tube sealingly
passes through the plate baffle; and/or at least one annular baffle
sealingly disposed between the first tube sheet and the second tube
sheet, wherein the heat exchanger tube sealingly passes through the
annular baffle; and directing a production fluid from the first
inlet to the first outlet to provide a flow of the production fluid
through the pressure vessel shell to produce the radial flow.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] (1) This application claims the benefit of U.S. Provisional
Patent Application Ser. No. 62/281,534 filed Jan. 21, 2016. The
related application is incorporated herein in its entirety by
reference.
BACKGROUND
[0002] (1) Field
[0003] This disclosure relates to fluid heating systems using shell
and tube heat exchangers.
[0004] (2) Description of the Related Art
[0005] Fluid heating systems, including steam, hydronic (water),
and thermal fluid boilers, constitute a broad class of devices for
producing a heated fluid for use in domestic, industrial, and
commercial applications. Because of the desire for improved energy
efficiency, compactness, reliability, and cost reduction, there
remains a need for improved fluid heating systems, as well as
improved methods of manufacture thereof.
SUMMARY
[0006] A fluid heating system or heat exchanger baffle assembly
comprising: a first tube sheet; a second tube sheet opposite the
first sheet; one or more heat exchanger tubes, which connects the
first tube sheet and the second tube sheet; and one or more plate
baffles and/or one or more annular baffles disposed between the
first tube sheet and the second tube sheet, wherein the heat
exchanger tubes sealingly pass through the baffles.
[0007] Also disclosed is a fluid heating system including a heat
exchanger comprising: a pressure vessel; a baffle assembly disposed
in the pressure vessel, the baffle assembly comprising a first tube
sheet, a second tube sheet opposite the first tube sheet, one or
more heat exchanger tubes which connect the first tube sheet and
the second tube sheet, an annular baffle and/or a plate baffle
disposed between the first tube sheet and the second tube
sheet.
[0008] Also disclosed is a fluid heating system including a heat
exchanger comprising: a pressure vessel; a first tube sheet; a
second tube sheet opposite the first sheet; one or more heat
exchanger tubes, which connects the first tube sheet and the second
tube sheet; one or more plate baffle assemblies disposed between
the first tube sheet and the second tube sheet, wherein the heat
exchanger tube sealingly passes through the plate baffles; and one
or more annular baffle assemblies sealing disposed between the
first tube sheet and the second tube sheet, wherein the heat
exchanger tubes sealingly pass through the annular baffle.
[0009] Also disclosed is a method of producing radial flow in a
fluid heating system or heat exchanger heat exchanger, the method
comprising: providing a heat exchanger comprising a baffle assembly
comprising a pressure vessel shell comprising an inlet and outlet;
a baffle assembly entirely disposed in the pressure vessel shell;
the baffle assembly comprising a first tube sheet, a second tube
sheet opposite the first sheet, one or more heat exchanger tubes
which connects the first tube sheet and the second tube sheet; at
least one plate baffle disposed between the first tube sheet and
the second tube sheet, wherein the heat exchanger tube sealingly
passes through the baffle; at least one annular baffle and/or at
least one plate baffle sealingly disposed between the first tube
sheet and the second tube sheet, wherein the heat exchanger tube
sealingly passes through the baffle; and directing a production
fluid from the first inlet to the first outlet to provide a flow of
the production fluid through the pressure vessel shell to produce
the radial flow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The patent or application file contains at least one drawing
executed in color. Copies of this patent or patent application
publication with color drawing(s) will be provided by the Office
upon request and payment of the necessary fee.
[0011] The above and other advantages and features of this
disclosure will become more apparent by describing in further
detail exemplary embodiments thereof with reference to the
accompanying drawings, in which:
[0012] FIG. 1A is a schematic diagram of an embodiment of a fluid
heating system which includes an embodiment of a combustion gas
supply system;
[0013] FIG. 1B is a color photograph of a region of a fluid heating
system shell-and-tube heat exchanger damaged by water boiling near
a production fluid baffle;
[0014] FIG. 1C is a perspective view of an embodiment of a
shell-and-tube heat exchanger incorporating a plate baffle assembly
that directs production fluid back-and-forth across the surfaces of
adjacent baffle plates;
[0015] FIG. 1D is a view of a circular plate baffle where the
production fluid is directed across the surface of the plate baffle
along a chord;
[0016] FIG. 2 is a longitudinal cross-sectional view of an
embodiment of a shell-and-tube heat exchanger incorporating a plate
baffle assembly;
[0017] FIG. 3 is a perspective view of an embodiment of a plate
baffle showing the heat exchanger tube holes and the mounting
flanges;
[0018] FIG. 4 is a side view of an embodiment of a plate baffle
assembly showing the plate baffle, the gasket and the retainer with
fasteners;
[0019] FIG. 5 shows a cross-sectional schematic of an embodiment of
a plate baffle assembly showing the gasket seal between the baffle
and the outer wall of a heat exchanger tube;
[0020] FIG. 6 is a longitudinal cross-sectional view of a
shell-and-tube heat exchanger incorporating an annular baffle
assembly;
[0021] FIG. 7 is a perspective view of an embodiment of an annular
baffle showing the heat exchanger tube holes and the mounting
flanges;
[0022] FIG. 8 shows a cross-sectional schematic of an embodiment of
an annular baffle assembly showing the gasket seal between the
baffle and the outer wall of a heat exchanger tube, and the gasket
seal between the baffle and the inner wall of the pressure
vessel;
[0023] FIG. 9 is a longitudinal cross-sectional view of an
embodiment of a shell-and-tube heat exchanger incorporating an
alternating plate and annular baffle assembly;
[0024] FIG. 10 is a perspective view of the shell-and-tube heat
exchanger of FIG. 9;
[0025] FIG. 11 is a perspective rendering of an embodiment of a
shell-and-tube heat exchanger incorporating an alternating plate
and annular baffle assembly and illustrating the radial flow
created by the baffle assembly;
[0026] FIG. 12 shows a photograph of a full-scale prototype of a
fluid heating system incorporating alternating sealed plate and
annular baffles assemblies;
[0027] FIG. 13 shows a computational fluid dynamics (CFD) numerical
simulation of the flow field through the pressure vessel of an
embodiment of a shell-and-tube heat exchanger incorporating an
alternating plate and annular baffle assembly and illustrating the
radial flow created by the baffle assembly;
[0028] FIG. 14A shows a computational fluid dynamics (CFD)
numerical simulation of the flow field across the baffle closest to
the upper tube sheet with a baffle spacing of 0.75 inches between
the baffle and the tube sheet.
[0029] FIG. 14B shows a computational fluid dynamics (CFD)
numerical simulation of the flow field across the baffle closest to
the upper tube sheet with a baffle spacing of 1.25 inches between
the baffle and the tube sheet.
DETAILED DESCRIPTION
[0030] There remains a need for fluid heating systems which provide
more thermally compact designs, e.g., configurations that provide
an increased ratio between the power and volume or footprint of the
fluid heating systems (FHS), and which can be manufactured at a
reasonable cost, with satisfactory material requirements, and
reduced complexity. Improvements in the state-of-the-art for fluid
heating system design, methods, and manufacture that enable
increases in the thermal power achievable for a prescribed size or,
conversely, enable a reduction in size for a prescribed thermal
power level, accomplished for the same or lower manufacturing cost
and complexity, are desirable.
[0031] It has been unexpectedly discovered that methods for
reducing the size of fluid heating systems incorporating
shell-and-tube heat exchangers achieved by increasing the bulk heat
flux can exacerbate issues created by the non-uniform temperatures.
Areas within the heat exchanger where heat is concentrated can lead
to material failures, corrosion, and fouling. Where the temperature
exceeds the boiling point of the production fluid, adverse effects
may accumulate, particularly near structural joints or cracks that
precipitate a production fluid phase change. Not only is the
magnitude of the temperature non-uniformity generally increased,
but the number of locations or sites has also increased.
[0032] Methods for promoting a uniform velocity field within the
flow of production fluid through the pressure vessel promote a
uniform temperature distribution and efficient exchange of thermal
energy across the walls of the heat exchanger tubes. This is
achieved in classical heat exchanger design through some form of
baffling to direct the production fluid flow, or some other means
for controlling the fluid flow in a predictable manner. Baffling
may be done in only a few discreet locations to address known
issues, or they can be systemic, closely controlling the fluid flow
throughout the entire heat exchanger.
[0033] Disclosed in FIG. 1A is a schematic of a fluid heating
system 100. Ambient air is forced under pressure by a blower 102
through a conduit into a combustor 104, which comprises a furnace
106. In the furnace 106, a sustained combustion of a combination of
fuel and air is maintained, releasing heat energy and combustion
gases that travel through the upper tube sheet 105 and into a
plurality of heat exchanger tubes 115. After traversing the heat
exchanger tubes, the hot combustion gases pass through the lower
tube sheet 110, into the exhaust plenum 112 bounded by the exhaust
plenum shell 114, and through the exhaust port to be conveyed out
of the fluid heating system by an exhaust flue (not shown).
[0034] The production fluid is forced under pressure into an inlet
116, through the space 155 bounded by the pressure vessel 150
surrounding the heat exchanger tubes and out through the outlet
118. A baffle 108 can be placed around the heat exchanger tubes to
direct the flow of production fluid.
[0035] The capacity of the fluid heating system is total heat
transferred from the thermal transfer fluid to the production fluid
under standard conditions. By convention, when the production fluid
consists of a liquid (e.g., water, thermal fluid, or thermal oil)
the capacity is expressed in terms of British thermal units per
hour (BTU/hr); and when the production fluid comprises a gas or
vapor (e.g., steam) the standard unit of measurement is expressed
in horsepower (HP). In an embodiment wherein the production fluid
is a liquid (e.g., water, thermal fluid or thermal oil), the
capacity of the fluid heating system may be between 100,000 BTU/hr,
or 150,000 BTU/hr, or 200,000 BTU/hr, or 250,000 BTU/hr, or 300,000
BTU/hr, or 350,000 BTU/hr, or 400,000 BTU/hr, or 450,000 BTU/hr, or
500,000 BTU/hr, or 550,000 BTU/hr, or 600,000 BTU/hr, or 650,000
BTU/hr, or 700,000 BTU/hr, or 750,000 BTU/hr, or 800,000 BTU/hr, or
850,000 BTU/hr, or 900,000 BTU/hr to 50,000,000 BTU/hr, or
40,000,000 BTU/hr, or 30,000,000 BTU/hr, or 20,000,000 BTU/hr, or
15,000,000 BTU/hr, or 14,000,000 BTU/hr or 13,000,000 BTU/hr, or
12,000,000 BTU/hr, or 10,000,000 BTU/hr, or 8,000,000 BTU/hr, or
6,000,000 BTU/hr, or 5,000,000 BTU/hr, or 4,000,000 BTU/hr, or
3,000,000 BTU/hr, or 2,000,000 BTU/hr, or 1,000,000 BTU/hr, wherein
the foregoing upper and lower bounds can be independently combined.
Specifically mentioned is the range from 750,000 BTU/hr to
12,000,000 BTU/hr.
[0036] In the fluid heating system, where the production fluid
temperature exceeds its heat of vaporization, the production fluid
will boil and provide a vapor. This can occur where the flow
velocity is low and the production fluid remains in extended
contact with the hot surface; for example, near the heat exchanger
tubes, or upper or lower tube sheets. While not wanting to be bound
by theory, production fluid boiling is understood to cause a loss
of thermal efficiency, and sites that regularly experience boiling
are also regions where material failure, corrosion and fouling are
likely. FIG. 1B shows a region near the upper tube sheet of a
standard hydronic boiler where poor flow conditions and high
temperatures have routinely resulted in boiling and material
degradation of the heat exchanger tubes 115.
[0037] It has been unexpectedly discovered that the temperature and
mass flow distribution from the furnace into the tubesheet are not
homogenous. In all burner configurations, but particularly true for
those utilizing premixed surface combustion, there exists
temperature and flow gradients. The flow exiting the burner, and
driven closest to the furnace will transfer more of its thermal
energy into the furnace wall. The resulting temperature boundary
layer will flow down the wall, and primarily enter the tubes
closest to the perimeter. This results in a mass flow concentration
near the perimeter. Contrarily, the rest of the combustion flow
will be insulated from the furnace wall, and therefore will retain
more of its heat, and generally this hot flow will prefer tubes
closest to the center, the magnitude of which was extremely
surprising when discovered during CFD modeling of the flow field.
This result is so surprising since conventional design practice
predicts the turbulence of combustion would promote more even
mixing. Additionally, the pressure drop through the length of the
tubes would be expected to be much larger in magnitude than the
dynamic effects from confined flow, and the flow inside the tubes
in highly turbulent. This would be expected to even out the effect
on the flow field. Lastly, conventional practice would predict that
radiant heat transfer from the hottest gasses in the center (and
indeed from the flame itself) would also contribute to increasing
the uniformity of the temperature field.
[0038] The magnitude of the deviation within gas side temperature
field creates uneven heat transfer requirements on the water side
of the boiler. Specifically, higher water side heat transfer
coefficients (and thus velocity and turbulence) are required near
these concentrations of high temperature gas containing tubes.
[0039] Most heat exchangers are designed with round cross sections,
commonly cylinders. In an embodiment where the production fluid
flows across the face of each baffle surface along a chord of the
surface, alternating direction across the surface of adjacent
baffles (a "back and forth" baffle pattern design), the cross
section of flow is small at the entry of a given section (defined
by a chord length which is less than the diameter), then increases
as it reaches the center of the tube bundle (chord length equal to
diameter) and is then reduced again as the fluid reaches the
opposite side of the baffle section. FIG. 1C illustrates the
production fluid flow corresponding to the configuration described.
Production fluid moves through the pressure vessel back-and-forth
across the heat exchanger tubes, alternating direction in regions
between adjacent baffles by turning the flow 160 at the edges of
the baffle plates. FIG. 1D illustrates how the production average
fluid flow 165 is directed along chords across the baffles plate
through the spaces between adjacent heat exchanger tubes. While
such abrupt velocity changes at the edges of the baffles plates to
turn the flow direction are not in and of themselves detrimental,
the design results in two primary disadvantages.
[0040] Firstly, flow momentum dictates that the fluid will try to
flow in a straight line. The result is that the tubes at the
outside edges 170 tend to receive less flow than those at the
center. Secondly, even when the outside tubes are included in the
flow (through smart tube patterns, or additional baffling to force
flow into these regions), the increase in cross sectional area
means that flow velocity is reduced in the center of the bundle.
Depending on the configuration of the furnace and heat exchanger
tube top sheet, these center tubes are typically the hottest and
already at the highest risk of failure.
[0041] While not wanting to be bound by theory, these effects are
especially pronounced in single-pass, in-line heat exchangers
incorporating conventional mesh burners for firetube boilers.
Particularly in such design applications, the temperature of the
thermal transfer fluid exiting the furnace is highest at the center
as it impinges on the upper tube sheet and enters the heat
exchanger tubes closest to the centerline, and coolest near the
walls of the furnace as it impinges on the top tube sheet and
enters the heat exchanger tubes along the circumference. In such
applications, avoiding high temperatures near the centerline that
can cause boiling of the production fluid and material failure is
an important limiting design constraint.
[0042] It has also been unexpectedly discovered that radial flow of
production fluid through the collection of heat exchanger tubes is
effective at promoting a uniform, distribution of temperature and
flow velocity within the heat exchanger. Radial flow of the
production fluid can be arranged by design in a fluid heating
system using arrangements of baffles that cause the flow to
alternate between inward-directed radial flow towards the
longitudinal axis and outward-directed radial flow towards the
pressure vessel inner wall. Additionally, the geometry of
alternating radial flows ensures that peak velocities occur at the
center of the tube bundle, where they are most needed, as confirmed
by computational fluid dynamic (CFD) modeling simulation.
[0043] Furthermore, it has been unexpectedly discovered that
sealing the baffles to the heat exchanger tubes and the pressure
vessel inner surface substantially contribute to the creation of a
uniform temperature and velocity production fluid flow field.
Sealing the heat exchanger tubes to the baffles eliminates gaps
where production fluid can leak through a baffle, degrading the
desired radial flow and creating regions where low flow velocities
and high temperatures can concentrate. The disclosed configuration
provides unexpectedly improved uniformity in the production fluid
velocity and temperature field.
[0044] An embodiment of a baffle assembly promoting uniform
production flow conditions is shown in FIG. 2, the assembly
comprising an upper tube sheet 105A, a lower tube sheet 110A, and a
heat exchanger tube 115B, which connects the upper tube sheet and
the lower tube sheet. A baffle assembly 220 is disposed between the
upper tube sheet and the lower tube sheet, wherein the heat
exchanger tube sealingly passes through the baffle 250. The baffle
assembly is secured to the pressure vessel using a mounting flange
245.
[0045] As used herein, "sealingly" means that a seal is provided
between adjacent members (such as a heat exchanger tube and a
baffle; or an annular baffle and the pressure vessel) to
substantially or effectively preclude fluid flow between the
adjacent members. Specifically, sealingly disposed means that the
seal provided between two members allows for less than or equal to
10 volume percent (vol %), or 0 to 10 vol %, or 0 to 5 vol %, or 0
to 1 vol %, or 0 to 0.1 vol %, or 0 to 0.01 vol %, or 0 to 0.001
vol %, or 0 to 0.0001 vol % of the total fluid flow traversing the
baffle, to flow between the two members. For example, the seal can
be formed merely from the close proximity of the adjacent members
or the seal can be formed, for example, using a gasket or a weld.
In an embodiment, a region between the adjacent members is 80% to
100%, 90% to 99%, or 95% to 98% obscured, and preferably 95% to
100% obscured, wherein the foregoing percentage is determined as a
percentage of the area between the adjacent members.
[0046] As shown in FIG. 3, the plate baffle 225A may be in the
shape of a plate with a perimeter having any suitable geometry. The
plate may be rectilinear or curvilinear, and may have a disk shape,
an elliptical shape, a lobular shape, a square shape, a rectangular
shape, or any combination thereof. Each heat exchanger tube passes
through a hole 300 in the plate baffle. The baffle assembly may be
secured to the pressure vessel using a fastener that passes through
a hole 310 in a mounting flange 245A.
[0047] The components comprising the baffle assembly may each
independently comprise any suitable material, and may comprise a
metal such as iron, aluminum, magnesium, titanium, nickel, cobalt,
zinc, silver, copper, an alloy comprising at least one of the
foregoing, or a combination thereof. Representative metals include
carbon steel, mild steel, cast iron, wrought iron, stainless steel
(e.g., 304, 316, or 439 stainless steel), Monel, Inconel, bronze,
and brass. Specifically mentioned is an embodiment in which the
baffle assembly components are mild steel.
[0048] The plate baffle assembly is sealed to the heat exchanger
tubes to prevent production fluid flow in the gap between the
baffle and the tubes, thereby forcing the fluid across the
perimeter of the baffle assembly. The baffle assembly may be sealed
to the heat exchanger tubes using any suitable method, for example
by welding the heat exchanger tubes to the plate baffle, or sealing
the gap using an adhesive.
[0049] In another embodiment, the plate baffle may be sealed to the
heat exchanger tubes using a gasket, as shown in FIG. 4. In this
embodiment, the plate baffle assembly comprises a rigid plate
baffle element 225B, and a gasket 230A is disposed on a surface of
the plate baffle and between the rigid element and the heat
exchanger tube, wherein the gasket seals the baffle to the heat
exchanger tube where the heat exchanger tube passes through the
baffle. The gasket may be secured to the plate baffle using an
adhesive. A retainer 235A may also be used to secure the retainer
to the plate baffle using adhesive or fasteners 240A. Any suitable
adhesive may be used. Representative adhesives include a vinyl
ester, an epoxy, a phenolic, a silicone, a polyurethane, and a
fluorinated rubber.
[0050] The gasket used to seal the baffle to the heat exchanger
tubes may comprise an elastomer. Specifically mentioned is an
embodiment where the elastomer is an ethylene propylene diene
terpolymer.
[0051] An embodiment of the plate baffle assembly incorporating a
gasket and a retainer is shown in FIG. 5, where the gasket 230B is
disposed between the plate baffle 225C and the retainer 235B. In
the embodiment shown in FIG. 5, the retainer outer diameter is
smaller than the plate baffle diameter so that the gasket protrudes
515 from the baffle assembly and contacts the outer wall of the
heat exchanger tube 505, preferentially in the direction of the
retainer. As a result, fluid pressure forces the gasket against the
heat exchanger tube outer wall, promoting the seal. The shape of
the plate baffle and the seal between the baffle and the heat
exchanger tube forces the production fluid to flow across the
perimeter of the baffle assembly, between the edge of the baffle
assembly and the inner surface of the pressure vessel 150A.
[0052] As a result, the plate baffle assembly forces the production
fluid to flow radially, outward from the longitudinal centerline of
the heat exchanger and around the perimeter of the baffle.
[0053] Another embodiment of a baffle assembly promoting uniform
production flow conditions is shown in FIG. 6, the baffle assembly
comprising a pressure vessel 150B and an annular baffle assembly
630. The baffle assembly is sealingly disposed in the pressure
vessel, the sealed baffle assembly comprising an upper tube sheet
105B; a lower tube sheet 110B opposite the upper tube sheet; a heat
exchanger tube 115C which connects the upper tube sheet and the
second tube sheet; an annular baffle 615 disposed between the first
tube sheet and the second tube sheet, wherein the heat exchanger
tube passes through the annular baffle, the annular baffle has a
first side and an opposite second side, and the annular baffle has
an annular shape, wherein the sealed baffle assembly is sealingly
disposed in the pressure vessel such that least 51% of fluid
communication between the first side and the second side of the
baffle is through the center region bounded by the inner diameter
of the baffle annulus.
[0054] As shown in FIG. 7, the annular baffle 610A may be in the
shape of an annulus with an inner perimeter 700 and outer perimeter
701. The inner diameter 700 and outer perimeter 701 can each
independently have any suitable geometry, can be a rectilinear or
curvilinear, and can have a circular shape, an elliptical shape, a
lobular shape, a square shape, a rectangular shape, or any
combination thereof. The heat exchanger tube passes through a hole
710 in the annular baffle. The baffle assembly may be secured to
the pressure vessel using a fastener that passes through the hole
715 and is secured to a mounting flange on the pressure vessel
wall.
[0055] The circumference of the annular baffles is designed to be
disposed on the inner surface of the pressure vessel and may be
sealed by a weld or gasket or unsealed and mounted to the pressure
vessel at attachment points. The annular opening is a major factor
in specifying the fluid pressure drop in that heat exchanger
section. It has been discovered that the size of the annulus can be
chosen so that the first 1-3 inner rows of heat exchanger tubes
pass through the annulus. Thus the dimensions of the annulus can be
determined by the pressure drop characteristics of the flow through
the annulus, and not a fixed fraction of the baffle surface. For
plate baffles, the diameter is typically selected so that the
outermost tube row sealingly passes through the plate baffle.
[0056] The components comprising the annular baffle assembly may
each independently comprise any suitable material, and may comprise
a metal such as iron, aluminum, magnesium, titanium, nickel,
cobalt, zinc, silver, copper, and an alloy comprising at least one
of the foregoing. Representative metals include carbon steel, mild
steel, cast iron, wrought iron, stainless steel (e.g., 304, 316 or
439 stainless steel), Monel, Inconel, bronze, and brass.
Specifically mentioned is an embodiment in which the baffle
assembly components are mild steel.
[0057] The annular baffle assembly is sealed to the inner surface
of the pressure vessel to prevent production fluid flow in the gap
between the annular baffle and the pressure vessel, thereby forcing
the fluid across the inner perimeter of the baffle assembly and
through the center region bounded by the inner diameter of the
baffle annulus. The baffle assembly may be sealed to the pressure
vessel in any suitable way, including welding the annular baffle to
the pressure vessel inner surface, or sealing the gap using an
adhesive.
[0058] In another embodiment, the annular baffle may be sealed to
the inner surface of the pressure vessel using a gasket, as shown
in FIG. 8. In this embodiment, the annular baffle assembly
comprises a rigid annular baffle element 610A, and a gasket 615A is
disposed on a surface of the annular baffle and between the baffle
and the pressure vessel 150B, wherein the gasket seals the baffle
to the pressure vessel. The gasket may be secured to the annular
baffle using an adhesive. A retainer 620A may also be used to
secure the retainer to the annular baffle using adhesive or
fasteners.
[0059] The gasket used to seal the baffle to the heat exchanger
tubes may comprise an elastomer. Any suitable elastomer may be
used. Specifically mentioned is an embodiment where the elastomer
is an ethylene propylene diene terpolymer.
[0060] An embodiment of the annular baffle assembly incorporating a
gasket and retainer is further shown in FIG. 8 where the gasket
615A is disposed between the annular baffle 610A and the retainer
620A. The retainer outer diameter is smaller than the plate baffle
diameter so that the gasket protrudes 810 from the baffle assembly
and contacts the inner wall of the pressure vessel 150B,
preferentially in the direction of the retainer. As a result, fluid
pressure forces the gasket against the pressure vessel inner wall,
promoting the seal. The shape of the annular baffle and the seal
between the baffle and the pressure vessel forces the production
fluid to flow across the inner perimeter of the baffle assembly
annulus through the center region bounded by the inner diameter of
the baffle annulus.
[0061] The annular baffle assembly may further be sealed to the
heat exchanger tubes to prevent production fluid flow in the gap
between the baffle and the tubes, thereby forcing the fluid across
the inner perimeter of the annular baffle assembly. The baffle
assembly may be sealed to the heat exchanger tubes in a variety of
ways including welding the heat exchanger tubes to the annular
baffle, or sealing the gap using an adhesive.
[0062] An embodiment of the annular baffle assembly incorporating a
gasket and a retainer to further seal the baffle to the heat
exchanger tubes is also shown in FIG. 8, where the gasket 615A is
disposed between the annular baffle 610A and the retainer 620A. The
retainer outer diameter is smaller than the annular baffle diameter
so that the gasket protrudes 800 from the baffle assembly and
contacts the outer wall of the heat exchanger tube 505A,
preferentially in the direction of the retainer. As a result, fluid
pressure forces the gasket against the heat exchanger tube outer
wall, promoting the seal. The shape of the annular baffle and the
seal between the baffle and the heat exchanger tube further forces
the production fluid to flow across the inner perimeter of the
baffle assembly annulus through the center region bounded by the
inner diameter of the baffle annulus.
[0063] As a result, the annular baffle assembly forces the
production fluid to flow radially, inward towards the longitudinal
centerline of the heat exchanger and through the center region
bounded by the inner diameter of the baffle annulus.
[0064] An another embodiment, the plate and annular baffle assembly
can be used in conjunction to maintain a predominately radial flow
pattern in the production fluid along the length of the fluid
heating system heat exchanger.
[0065] FIG. 9 shows an embodiment of a fluid heating system sealed
baffle assembly comprising: an upper tube sheet 205B; a lower tube
sheet 210B opposite the upper tube sheet; a heat exchanger tube
115D, which connects the upper tube sheet and the lower tube sheet;
and a plate baffle assembly 220A disposed between the upper tube
sheet and the lower tube sheet, wherein the heat exchanger tube
sealingly passes through the plate baffle assembly; and an annular
baffle assembly 630A disposed between the upper tube sheet and the
lower tube sheet, wherein the heat exchanger tube sealingly passes
through the annular baffle.
[0066] An embodiment where the plate and annular baffles alternate
along the length of the heat exchanger is further shown in FIG. 10.
In this embodiment three annular baffles 630B alternate with two
plate baffles 220B. The heat exchanger tubes sealingly pass through
both types of baffles, and the annular baffles are sealed to the
pressure vessel inner surface (not shown).
[0067] The flow pattern induced by the alternating plate and
annular baffles is illustrated in the rendering shown in FIG. 11,
where production fluid entering the inlet 1100 flows through the
center region of the first annular baffle assembly 1105, turns
outward and flows radially 1110 to the outer perimeter of the first
plate baffle assembly 1120 where it is turned inward to again flow
radially to the center region of the second annular baffle assembly
1130. This alternating radial flow pattern continues until the
production fluid passes through the outlet (not shown) and out of
the pressure vessel.
[0068] The selection of the number of baffles, and the spacing
between them is highly dependent on the performance and fluid
desired for the product. The measure of optimality for this design
process can be stated as: minimizing the fluid side pressure drop
as the fluid moves from pressure vessel inlet to the outlet
(subject to operational constraints, where larger pressure drops
result in larger pumping requirements and overall reduction in
system efficiencies once installed), while simultaneously
minimizing the number and magnitude of local tube temperature
outliers, subject to a given threshold temperature. Most often the
temperature threshold selected is the vaporization temperature for
the given fluid, at the given operating pressure, but can be
selected based on any number of measures, durability or otherwise,
including but not limited to material temperature limits,
production fluid temperature limits, thermal stress limits, or any
other suitable measure.
[0069] Variables important for the optimization of the baffle
spacing, attachment and design geometry are many including, but not
limited to: the production fluid viscosity, boiling point, density,
specific heat, and thermal conductivity; the heat exchanger tube
geometry, heat exchanger tube material; and the pressure drop
constraints. Also important is the design flow rate of production
fluid from the pressure vessel inlet to outlet which is often
specified by a temperature change from the inlet to outlet, at a
given heat input.
[0070] Standard heat exchanger design references recommend the
minimum spacing between the baffles be 20% of the shell diameter.
(Shah, Ramesh K., and Dusan P. Sekulic. "Fundamentals of heat
exchanger design", John Wiley & Sons, 2003.) In products with
high heat flux, the flow velocity may be insufficient to keep the
metals temperatures below the production fluid boiling temperature
which creates an important constraint. Reducing the baffle
separation distance does not solve the problem since the pressure
gradient promotes the leakage flow rather than the main cross flow.
Sealing the baffle provides an approach to exceed conventional
design limits since it enables flow velocities and heat transfer
coefficients required to avoid local boiling temperatures without
the leakage side effects.
[0071] In an embodiment wherein the production fluid is a liquid
(e.g., water, thermal fluid or thermal oil), the temperature
difference between the pressure vessel inlet and outlet can be
between 180 degrees centigrade (.degree. C.), or 170.degree. C., or
160.degree. C., or 150.degree. C., or 140.degree. C., or
130.degree. C., or 120.degree. C., or 110.degree. C., or
105.degree. C., or 100.degree. C., or 95.degree. C., or 90.degree.
C., or 85.degree. C., or 80.degree. C., or 75.degree. C., or
70.degree. C., or 65.degree. C., or 60.degree. C., or 55.degree.
C., or 50.degree. C., or 45.degree. C., or 40.degree. C., or
35.degree. C., or 30.degree. C., or 25.degree. C., or 20.degree.
C., or 15.degree. C., or 10.degree. C. The temperature difference
range 110.degree. C. to 30.degree. C. is specifically mentioned.
Depending upon the geometric, thermal, fluid and material
properties of the embodiment, the separation distance between
baffle plates may be between 300 centimeters (cm), or 250 cm, or
200 cm, or 150 cm, or 100 cm, or 90 cm, or 80 cm, or 70 cm, or 60
cm, or 50 cm, or 40 cm, or 35 cm, or 30 cm, or 26 cm, or 24 cm, or
22 cm, or 20 cm, or 18 cm, or 16 cm, or 14 cm, or 12 cm, or 10 cm,
or 8 cm to 6 cm, or 5 cm, or 4 cm, or 3 cm, or 2 cm, or 1.5 cm, or
1 cm, or 0.5 cm or 0.25 cm, wherein the foregoing upper and lower
bounds can be independently combined. The gap distance range from
1.5 cm to 50 cm is specifically mentioned.
[0072] An optimum spacing can be determined for combinations of
design variables and fluid properties. Computation Fluid Dynamic
(CFD) numerical simulation can be used to design the baffle system
and, in particular, the spacing between the baffle plates
accounting for each of the design variables. For instance, a baffle
set designed for a hydronic fluid heating systems with a 20 degrees
Fahrenheit (.degree. F.) temperature difference between the
pressure vessel inlet and outlet, will have significantly different
optimal spacing requirements than one designed for a 40.degree. F.
temperature difference, where the production fluid is glycol or a
combined glycol and water mixture.
[0073] However, it has been unexpectedly discovered that the
baffles can be arranged where the baffles are sealed to the tubes,
or where the baffles are unsealed, with similar results at the
beginning of life. Where the baffles are unsealed, the small amount
of leakage flow where the heat exchanger tubes pass through the
baffle holes acts to break up vortices and stagnant flow areas,
whereas if the baffles are sealed, more baffles are required to
ensure these areas of low, or cyclical flow are managed so as not
to cause a durability issue.
[0074] Also surprising is the discovery that unsealed baffles have
radically different performance characteristics over their life
span. Specifically, the result can be a solution, which is
indeterminate with respect to time. In other words, the system can
be designed such that extreme changes in performance and symmetry
can present themselves over time during the systems life in the
field. Once a radial flow pattern has been selected, the system is
inherently designed with a high degree of axial symmetry. During
system operation, small amounts of debris tend to get caught in the
gap between the baffle and the tube and corrosion material will
build-up over time. A loss of leakage flow through a given baffle
to tube space is irrelevant in a local sense; however, as the
debris does not deposit symmetrically around the axis, the blocked
local leakage flow can have a major impact on the flow symmetry
which has a significant effect downstream in the heat
exchanger.
[0075] While the effects of symmetry on the dynamics and stability
of fluid flow systems has been considered in other engineering
fields, the study of fluid flow in a heat exchanger is particularly
complex. In the case of unsealed baffles, when the flow symmetry
surrounding the tubes and around the circumference of the plate
baffles is broken where debris or corrosion material clogs the
gaps, the production fluid flow is disrupted causing a new flow
field and resulting temperature distribution. The perturbations in
the flow and temperature fields can be dramatic, even for small
changes in the geometry caused by particulate clogging of the gaps.
In fact, this sensitive dependence upon flow conditions were
observed during instrumented prototype testing where a single test
rig would exhibit significantly different temperature field
behavior from test to test as debris accumulated and sifted in the
unsealed gaps. This sensitive dependence on the precise geometry of
the gaps was eliminated by sealing.
[0076] As is discussed above, an advantage of the disclosed system
is that it can provide a more uniform production fluid flow field
which is predominately radial, minimizing areas of high temperature
that are understood to cause material failures, fluid boiling, and
loss of thermal efficiency. The disclosed baffle assembly and heat
exchanger provides for improvement in the management of production
fluid flow of fluid heating systems and heat exchangers that enable
greater compactness, reliability and performance in these
systems.
[0077] Presented below are non-limiting examples of the present
disclosure.
EXAMPLES
Example 1
[0078] Two fluid heating systems with alternating annular and plate
baffles configurations were constructed and instrumented based on
the embodiment illustrated in FIG. 9 for the purpose of comparing
the advantages of sealing the baffles to the heat exchanger tubes
and pressure vessel compared to leaving these areas unseal and
allowing flow the gaps formed between these structures.
[0079] The first of the two fluid heating test systems comprises a
heat exchanger with five baffle plates and 275 heat exchanger tubes
in a boiler that is supplied with a heat input of 3 million BTU/hr.
The production fluids tested were water and various mixtures of
water and glycol. The gaps formed between the openings in the
baffles where the heat exchanger tubes penetrate the baffles were
between 0.0 cm (contact surfaces) and 0.5 cm and were unsealed,
allowing a flow of production fluid through the gaps.
[0080] The first (unsealed) fluid heating test system was
instrumented with thermocouples at various positions in each
region, T.sub.2 through T.sub.5 shown in FIG. 9, between the set of
five baffles to measure the evolution of production fluid
temperatures over time as the test units were operated under
installed conditions. The system was operated under normal
installation conditions for 118 days and the temperatures at each
of the measurement points was recorded at the beginning and end of
the test period. The second and third columns of TABLE 1 show the
results. For each fluid region, the average of the temperature
difference range from the beginning to the end of the test period
is shown, together with the standard deviation of the temperature
ranges measured. These data provide a measurement of the average
temperature deviation of the test period together with the variance
of the temperature deviations. These data show large variations in
the temperature measurements over the test period, due to the
accumulation of debris and corrosion in the unsealed gaps between
the baffles and heat exchanger tubes which changes the production
fluid flow pattern over (relatively short) time periods away from
the target design conditions.
[0081] The second of the two fluid heating test systems comprises a
heat exchanger with seven baffle plates and 275 heat exchanger
tubes in a system configuration that is supplied with a heat input
of 3 million BTU/hr. A view of the heat exchanger is shown in FIG.
12 with the pressure vessel removed where a plate baffle assembly
1200 and an annular baffle assembly 1210 is visible. Heat exchanger
tubes pass through the alternating sequence of plate and annular
baffles assemblies, sealed by gaskets and held in place by
retainers as shown in FIG. 8. The production fluids tested were
water and various mixtures of water and glycol. The gaps formed
between the openings in the baffles where the heat exchanger tubes
penetrate the baffles were between 0 cm (contact surfaces) and 0.3
cm and were sealed, preventing the flow of production fluid through
the baffle plates where the heat exchanger tubes sealingly pass
through the baffles.
[0082] The second (sealed) fluid heating test system was
instrumented with thermocouples at various positions in each
region, T.sub.2 through T.sub.5 shown in FIG. 9, between the set of
seven baffles to measure the evolution of production fluid
temperatures over time as the test units were operated under
installed conditions. The system was operated under normal
installation conditions for 16 days and the temperatures at each of
the measurement points was recorded at the beginning and end of the
test period. The fourth and fifth columns of TABLE 1 show the
results. For each fluid region, the average of the temperature
difference range from the beginning to the end of the test period
is shown, together with the standard deviation of the temperature
ranges measured. These data provide a measurement of the average
temperature deviation of the test period together with the variance
of the temperature deviations. These data reduced variations in the
temperature measurements over the test period, since debris and
corrosion can no longer accumulate in the gaps between the baffles
and heat exchanger tubes. As a result, the production fluid flow
pattern over is stabilized at or near the target design
conditions.
TABLE-US-00001 TABLE 1 Fluid Heating Fluid Heating Test System 1
Test System 2 (Unsealed Gaps) (Sealed Gaps) Average Std. Dev. Of
Average Std. Dev. Test Temp Temp Temp Of Temp Region Range
(.degree. F.) Range (.degree. F.) Range (.degree. F.) Range
(.degree. F.) T.sub.2 4.8 2.0 2.9 1.8 T.sub.3 21.3 13.4 3.4 1.2
T.sub.4 15.2 6.9 6.4 4.3 T.sub.5 7.0 3.9 11.5 8.5
Example 2
[0083] A computational fluid dynamics (CFD) simulation of the fluid
heating system prototype shown in FIG. 12 was performed.
TABLE-US-00002 Operating Conditions: Input: 3,000,000 BTU/hr (878.4
kW) Inlet Temperature: 80.degree. F. (26.6.degree. C.) Outlet
Temperature: 180.degree. F. (82.2.degree. C.) Geometry: Tube
Length: 40 inches (1.016m) Tube Outside Diameter: 0.5 inches
(12.7e-3m) Number of Tubes 275 Inlet Inside Diameter: 4 inches
(1.016e-1m) Pressure Vessel Inside Diameter: 23.5 inches
(5.969e-1m) Baffle Spacing: 2, 5, 8, 8, 8, 9 inches Plate Baffle
Diameter: 19 5/8 inches (4.985e-1m) Annular Baffle Inside Diameter:
6 1/8 in (1.555e-1m) (Annulus Outside Diameter Equals Pressure
Vessel Shell Inside Diameter)
[0084] FIG. 13 shows the nearly uniform flow field generated by the
alternating sequence of plate and annular baffles.
Example 3
[0085] A computational fluid dynamics (CFD) simulation of the fluid
heating system prototype shown in FIG. 12 was performed.
TABLE-US-00003 Operating Conditions: Input: 3,000,000 BTU/hr (878.4
kW) Inlet Temperature: 80.degree. F. (26.6.degree. C.) Outlet
Temperature: 120.degree. F. (48.9.degree. C.)
[0086] In this simulation, the separation distance between the heat
exchanger top sheet and the first baffle plate (forming the region
T.sub.1 in FIG. 9) was varied to illustrate the changes in
production flow field uniformity as a function of baffle separation
distance.
[0087] In FIG. 14A the separation between the top sheet and the
first baffle was 0.75 inches. At this separation distance and these
simulated operating conditions, the flow field shows a pronounced
region of reduced flow velocity near the centerline 1405. FIG. 14B
shows a simulation with the same geometry and operating conditions,
but the separation between the top sheet and the first baffle has
been increased to 1.25 inches. At this increased separation
distance, the flow field is more uniform including the flow
velocity near the centerline 1415. A design objective is to
minimize the separation distance while achieving a relatively
uniform flow field across the face of the baffle. In many cases the
uniformity of flow must be weighed against the specific temperature
needs of the tubes in that flow region. As a result, either spacing
could be considered "optimal" pending the specific case in
question.
[0088] An embodiment is disclosed with a baffle assembly
comprising: a first tube sheet; a second tube sheet opposite the
first sheet; a heat exchanger tube, which connects the first tube
sheet and the second tube sheet; and a baffle disposed between the
first tube sheet and the second tube sheet, wherein the heat
exchanger tube passes through the baffle; wherein the baffle is a
plate baffle, and wherein the plate baffle has a disk shape, an
elliptical shape, a lobular shape, a square shape, a rectangular
shape, a rectilinear shape, or a curvilinear shape, or any
combination thereof; wherein the baffle has a disk shape; wherein
the baffle has a first side and an opposite second side, and
wherein fluid communication between the first side and the second
side is across a perimeter of the baffle; wherein a maximum
distance between an outer surface of the heat exchanger tube and
the baffle is between 0 centimeters and 3 centimeters; wherein the
sealed baffle assembly comprises a plurality of heat exchanger
tubes, and wherein each heat exchanger tube independently
penetrates the baffle; wherein the plurality of heat exchanger
tubes comprises 50 to 5000 heat exchanger tubes; wherein the baffle
assembly comprises a plurality of baffles, and wherein each heat
exchanger tube penetrates each baffle; wherein the plurality of
baffles comprises 1 to 100 baffles; wherein the baffle has an
aspect ratio of 5 to 10,000, wherein the aspect ratio is a largest
dimension of a major surface of the baffle divided by a thickness
of the baffle.
[0089] An embodiment is disclosed with a baffle assembly
comprising: a first tube sheet; a second tube sheet opposite the
first sheet; a heat exchanger tube, which connects the first tube
sheet and the second tube sheet; and a baffle disposed between the
first tube sheet and the second tube sheet, wherein the heat
exchanger tube sealingly passes through the baffle; wherein the
baffle is a plate baffle, and wherein the plate baffle has a disk
shape, an elliptical shape, a lobular shape, a square shape, a
rectangular shape, a rectilinear shape, or a curvilinear shape, or
any combination thereof; wherein the baffle has a disk shape;
wherein the baffle has a first side and an opposite second side,
and wherein fluid communication between the first side and the
second side is exclusively across a perimeter of the baffle;
wherein a maximum distance between an outer surface of the heat
exchanger tube and the baffle is between 0 centimeters and 3
centimeters; further comprising a continuous weld, which sealingly
connects the baffle to the heat exchanger tube; wherein the
continuous weld which sealingly connects the baffle to the heat
exchanger tube is disposed on a circumference of the tube; further
comprising an adhesive, which adhesively and sealingly connects the
baffle to the heat exchanger tube, and wherein the adhesive is
disposed between the heat exchanger tube passes and the baffle;
wherein the baffle comprises a rigid element, and a gasket disposed
on a surface of the rigid element and between the rigid element and
the heat exchanger tube, wherein the gasket seals the baffle to the
heat exchanger tube where the heat exchanger tube passes through
the baffle; wherein the gasket is attached to the rigid element by
an adhesive; further comprising a retainer, which is attached to
the rigid element by a fastener, and wherein the gasket is disposed
between the rigid element and the retainer; wherein the gasket
comprises an elastomer; wherein the elastomer is ethylene propylene
diene monomer; wherein the gasket comprises a metal plate with a
maximum thickness between 0.002 millimeters to 6 millimeters;
wherein the sealed baffle assembly comprises a plurality of heat
exchanger tubes, and wherein each heat exchanger tube independently
sealingly penetrates the baffle; wherein the plurality of heat
exchanger tubes comprises 50 to 5000 heat exchanger tubes; wherein
the sealed baffle assembly comprises a plurality of baffles, and
wherein each heat exchanger tube sealingly penetrates each baffle;
wherein the plurality of baffles comprises 3 to 100 baffles;
wherein the baffle has an aspect ratio of 5 to 10,000, wherein the
aspect ratio is a largest dimension of a major surface of the
baffle divided by a thickness of the baffle.
[0090] Set forth below are non-limiting embodiments of the present
disclosure.
[0091] An embodiment is disclosed with a baffle assembly
comprising: a first tube sheet; a second tube sheet opposite the
first sheet; a heat exchanger tube, which connects the first tube
sheet and the second tube sheet; and a baffle disposed between the
first tube sheet and the second tube sheet, wherein the heat
exchanger tube passes through the baffle; wherein the baffle is a
plate baffle, and wherein the plate baffle has a disk shape, an
elliptical shape, a lobular shape, a square shape, a rectangular
shape, a rectilinear shape, or a curvilinear shape, or any
combination thereof; wherein the baffle has a disk shape; wherein
the baffle has a first side and an opposite second side, and
wherein fluid communication between the first side and the second
side is across a perimeter of the baffle; wherein a maximum
distance between an outer surface of the heat exchanger tube and
the baffle is between 0 centimeters and 3 centimeters;; wherein the
sealed baffle assembly comprises a plurality of heat exchanger
tubes, and wherein each heat exchanger tube independently
penetrates the baffle; wherein the plurality of heat exchanger
tubes comprises 50 to 5000 heat exchanger tubes; wherein the baffle
assembly comprises a plurality of baffles, and wherein each heat
exchanger tube penetrates each baffle; wherein the plurality of
baffles comprises 1 to 100 baffles; wherein the baffle has an
aspect ratio of 5 to 10,000, wherein the aspect ratio is a largest
dimension of a major surface of the baffle divided by a thickness
of the baffle.
[0092] An embodiment is disclosed with a baffle assembly
comprising: a first tube sheet; a second tube sheet opposite the
first sheet; a heat exchanger tube, which connects the first tube
sheet and the second tube sheet; and a baffle disposed between the
first tube sheet and the second tube sheet, wherein the heat
exchanger tube sealingly passes through the baffle; wherein the
baffle is a plate baffle, and wherein the plate baffle has a disk
shape, an elliptical shape, a lobular shape, a square shape, a
rectangular shape, a rectilinear shape, or a curvilinear shape, or
any combination thereof; wherein the baffle has a disk shape;
wherein the baffle has a first side and an opposite second side,
and wherein fluid communication between the first side and the
second side is exclusively across a perimeter of the baffle;
wherein a maximum distance between an outer surface of the heat
exchanger tube and the baffle is between 0 centimeters and 3
centimeters; further comprising a continuous weld, which sealingly
connects the baffle to the heat exchanger tube; wherein the
continuous weld which sealingly connects the baffle to the heat
exchanger tube is disposed on a circumference of the tube; further
comprising an adhesive, which adhesively and sealingly connects the
baffle to the heat exchanger tube, and wherein the adhesive is
disposed between the heat exchanger tube passes and the baffle;
wherein the baffle comprises a rigid element, and a gasket disposed
on a surface of the rigid element and between the rigid element and
the heat exchanger tube, wherein the gasket seals the baffle to the
heat exchanger tube where the heat exchanger tube passes through
the baffle; wherein the gasket is attached to the rigid element by
an adhesive; further comprising a retainer, which is attached to
the rigid element by a fastener, and wherein the gasket is disposed
between the rigid element and the retainer; wherein the gasket
comprises an elastomer; wherein the elastomer is ethylene propylene
diene monomer; wherein the gasket comprises a metal plate with a
maximum thickness between 0.002 millimeters to 6 millimeters;
wherein the sealed baffle assembly comprises a plurality of heat
exchanger tubes, and wherein each heat exchanger tube independently
sealingly penetrates the baffle; wherein the plurality of heat
exchanger tubes comprises 50 to 5000 heat exchanger tubes; wherein
the sealed baffle assembly comprises a plurality of baffles, and
wherein each heat exchanger tube sealingly penetrates each baffle;
wherein the plurality of baffles comprises 3 to 100 baffles;
wherein the baffle has an aspect ratio of 5 to 10,000, wherein the
aspect ratio is a largest dimension of a major surface of the
baffle divided by a thickness of the baffle.
[0093] Embodiment 1: A baffle assembly comprising: a first tube
sheet; a second tube sheet opposite the first sheet; a heat
exchanger tube, which connects the first tube sheet and the second
tube sheet; and a baffle disposed between the first tube sheet and
the second tube sheet, wherein the heat exchanger tube passes
through the baffle, optionally, wherein the heat exchanger tube
sealingly passes through the baffle.
[0094] Embodiment 2: The baffle assembly of embodiment 1, wherein
the baffle has a disk shape, an elliptical shape, a lobular shape,
a square shape, a rectangular shape, a rectilinear shape, or a
curvilinear shape, or any combination thereof.
[0095] Embodiment 3: The baffle assembly of any of embodiments 1 or
2, wherein the baffle has a disk shape.
[0096] Embodiment 4: The baffle assembly of any of embodiments 1 to
3, wherein the baffle comprises a plate baffle that has a first
side and an opposite second side, and wherein fluid communication
between the first side and the second side is across a perimeter of
the baffle. At least 51%, or at least 90%, or at least 99% by
weight of fluid communication between the first side and the second
side of the baffle can be through the perimeter of the baffle.
[0097] Embodiment 5: The baffle assembly of any of embodiments 1 to
4, wherein the baffle comprises an annular baffle that has a first
side and an opposite second side, and wherein fluid communication
between the first side and the second side is across an annulus of
the baffle. At least 51%, or at least 90%, or at least 99% by
weight of fluid communication between the first side and the second
side of the baffle can be through the annulus of the annular
baffle.
[0098] Embodiment 6: The baffle assembly of any of embodiments 1 to
5, wherein a maximum distance between an outer surface of the heat
exchanger tube and the baffle is between 0 centimeters and 3
centimeters.
[0099] Embodiment 7: The baffle assembly of any of embodiments 1 to
6, further comprising a continuous weld, which sealingly connects
the baffle to the heat exchanger tube; or wherein a seal is formed
between the heat exchanger tubes and the baffle based on a close
proximity of the heat exchanger tubes and the baffle.
[0100] Embodiment 8: The baffle assembly of embodiment 7, further
comprising the weld; wherein the continuous weld which sealingly
connects the baffle to the heat exchanger tube is disposed on a
circumference of the tube.
[0101] Embodiment 9: The baffle assembly of any of embodiments 1 to
8, further comprising an adhesive, which adhesively and sealingly
connects the baffle to the heat exchanger tube, and wherein the
adhesive is disposed between the heat exchanger tube passes and the
baffle.
[0102] Embodiment 10: The baffle assembly of any of embodiments 1
to 9, wherein the baffle comprises a rigid element, and a gasket
disposed on a surface of the rigid element and between the rigid
element and the heat exchanger tube, wherein the gasket seals the
baffle to the heat exchanger tube where the heat exchanger tube
passes through the baffle.
[0103] Embodiment 11: The baffle assembly of embodiment 10, wherein
the gasket is attached to the rigid element by an adhesive.
[0104] Embodiment 12: The baffle assembly of any of embodiments 10
to 11, further comprising a retainer, which is attached to the
rigid element by a fastener, and wherein the gasket is disposed
between the rigid element and the retainer.
[0105] Embodiment 13: The baffle assembly of any of embodiments 10
to 12, wherein the gasket comprises an elastomer.
[0106] Embodiment 14: The baffle assembly of any of embodiments 10
to 13, wherein the elastomer is ethylene propylene diene
monomer.
[0107] Embodiment 15: The baffle assembly of any of embodiments 10
to 14, wherein the gasket comprises a metal plate with a maximum
thickness between 0.002 millimeters to 6 millimeters.
[0108] Embodiment 16: The baffle assembly of any of embodiments 1
to 15, wherein the baffle assembly comprises a plurality of heat
exchanger tubes, and wherein each heat exchanger tube independently
sealingly penetrates the baffle.
[0109] Embodiment 17: The baffle assembly of any of embodiments 1
to 16, wherein the plurality of heat exchanger tubes comprises 50
to 5000 heat exchanger tubes.
[0110] Embodiment 18: The baffle assembly of any of embodiments 1
to 17, wherein the baffle assembly comprises a plurality of
baffles, and wherein each heat exchanger tube sealingly penetrates
each baffle.
[0111] Embodiment 19: The baffle assembly of any of embodiments 1
to 18, wherein the plurality of baffles comprises 3 to 100
baffles.
[0112] Embodiment 20: The baffle assembly of any of embodiments 1
to 19, wherein the baffle has an aspect ratio of 5 to 10,000,
wherein the aspect ratio is a largest dimension of a major surface
of the baffle divided by a thickness of the baffle.
[0113] Embodiment 21: The baffle assembly of any one of embodiments
1-20, wherein the baffle assembly comprises a plurality of baffles
comprising at least one plate baffle and at least one annular
baffle.
[0114] Embodiment 22: The baffle assembly of any one of embodiments
1 to 21, wherein a fluid flow through the baffle assembly
encounters an alternating route of plate baffles and annular
baffles.
[0115] Embodiment 23: A heat exchanger comprising: a pressure
vessel; and a baffle assembly disposed in the pressure vessel such
as the one described in any one of embodiments 1 to 22, the baffle
assembly comprising a first tube sheet, a second tube sheet
opposite the first tube sheet, a heat exchanger tube, which
connects the first tube sheet and the second tube sheet, a baffle
disposed between the first tube sheet and the second tube sheet,
wherein the heat exchanger tube passes through the baffle.
[0116] Embodiment 24: The heat exchanger of embodiment 23, wherein
a maximum distance between an inner surface of the pressure vessel
and an edge surface of the baffle is between 0 centimeters and 3
centimeters.
[0117] Embodiment 25: The heat exchanger of any of embodiments 23
to 24, further comprising a continuous weld, which sealingly
connects the annular baffle to the pressure vessel.
[0118] Embodiment 26: The heat exchanger of any of embodiments 23
to 25, wherein the continuous weld which sealingly connects the
annular baffle to the heat exchanger tube is disposed on a
perimeter of the baffle.
[0119] Embodiment 27: The heat exchanger of any of embodiments 23
to 26, further comprising an adhesive, which adhesively and
sealingly connects the baffle to the pressure vessel, and wherein
the adhesive is disposed on the perimeter of the baffle.
[0120] Embodiment 28: The heat exchanger of any of embodiments 23
to 27, wherein the baffle comprises a rigid element, and a gasket
disposed on the surface of the rigid element, wherein the gasket
seals the annular baffle to the pressure vessel on the perimeter of
the annular baffle.
[0121] Embodiment 29: The heat exchanger of embodiment 28, wherein
the gasket is attached to the rigid element by an adhesive.
[0122] Embodiment 30: The heat exchanger of any of embodiments 28
to 29, further comprising a retainer, which is attached to the
rigid element by a fastener, and wherein the gasket is disposed
between the rigid element and the retainer.
[0123] Embodiment 31: The heat exchanger of any of embodiments 28
to 30, wherein the gasket comprises an elastomer.
[0124] Embodiment 32: The heat exchanger of embodiment 31, wherein
the elastomer is ethylene propylene diene monomer.
[0125] Embodiment 33: The heat exchanger of any of embodiments 28
to 32, wherein the gasket comprises a metal plate having a maximum
thickness between 0.002 millimeters to 6.35 millimeters.
[0126] Embodiment 34: The heat exchanger of any of embodiments 23
to 33, wherein the heat exchanger tube sealingly passes through the
baffle, wherein the baffle comprises an annular baffle, and wherein
fluid communication between the first side and the second side of
the annular baffle is through the annulus of the baffle, for
example, exclusively across.
[0127] Embodiment 35: The heat exchanger of any of embodiments 23
to 34, wherein the heat exchanger tube sealingly passes through the
baffle, wherein the baffle comprises a plate baffle, and wherein
fluid communication between the first side and the second side of
the plate baffle is across the perimeter of the baffle, for
example, exclusively across.
[0128] Embodiment 36: The heat exchanger of any of embodiments 23
to 35, wherein a maximum distance between an outer surface of the
heat exchanger tube and the baffle is between 0 centimeters and 3
centimeters.
[0129] Embodiment 37: The heat exchanger of any of embodiments 23
to 36, further comprising a continuous weld, which sealingly
connects the baffle to the heat exchanger tube.
[0130] Embodiment 38: The heat exchanger of any of embodiments 23
to 37, wherein the continuous weld which sealingly connects the
baffle to the heat exchanger tube is disposed on a circumference of
the tube.
[0131] Embodiment 39: The heat exchanger of any of embodiments 23
to 38, further comprising an adhesive, which adhesively and
sealingly connects the baffle to the heat exchanger tube, wherein
the adhesive is disposed between the heat exchanger tube and the
baffle where the heat exchanger tube passes through the baffle.
[0132] Embodiment 40: The heat exchanger of any of embodiments 23
to 39, wherein the baffle comprises a rigid element, and a gasket
disposed on the surface of the rigid element, wherein the gasket
seals the baffle to the heat exchanger tube where the heat
exchanger tube passes through the baffle, and wherein the gasket
seals the baffle to the pressure vessel on the perimeter of the
baffle.
[0133] Embodiment 41: The heat exchanger of embodiment 40, wherein
the gasket is attached to the rigid element by the adhesive.
[0134] Embodiment 42: The heat exchanger of any of embodiments 40
to 41, further comprising a retainer, which is attached to the
rigid element by a fastener, and wherein the gasket is disposed
between the rigid element and the retainer.
[0135] Embodiment 43: The heat exchanger of any of embodiments 40
to 42, wherein the gasket comprises an elastomer.
[0136] Embodiment 44: The heat exchanger of any of embodiments 40
to 43, wherein the elastomer is ethylene propylene diene
monomer.
[0137] Embodiment 45: The heat exchanger of any of embodiments 40
to 44, wherein the gasket comprises a metal plate having a maximum
thickness between 0.002 millimeters to 6 millimeters.
[0138] Embodiment 46: The heat exchanger of any of embodiments 23
to 45, wherein the heat exchanger assembly comprises a plurality of
heat exchanger tubes, and wherein each heat exchanger tube
independently and penetrates the baffle.
[0139] Embodiment 47: The heat exchanger of embodiment 46, wherein
the plurality of heat exchanger tubes comprises 50 to 5000 heat
exchanger tubes.
[0140] Embodiment 48: The heat exchanger of embodiments 23 to 47,
comprising a plurality of annular baffles and/or plate baffles,
wherein each baffle is sealingly disposed between the first tube
sheet and the second tube sheet.
[0141] Embodiment 49: The heat exchanger of any of embodiments 23
to 48, wherein the heat exchanger comprises a plurality of annular
baffles and/or plate baffles, and wherein each heat exchanger tube
penetrates each baffle.
[0142] Embodiment 50: The heat exchanger of any of embodiments 23
to 49, wherein the plurality of baffles comprises 3 to 100
baffles.
[0143] Embodiment 51: The baffle assembly or the heat exchanger of
any of the preceding embodiments, wherein a seal is formed between
the baffle and the heat exchanger tube based solely on a close
proximity to each other.
[0144] Embodiment 52: The baffle assembly or the heat exchanger of
any of the preceding embodiments, wherein a region between the
baffle and the heat exchanger tube is 80% to 100% obscured, wherein
the foregoing percentage is determined as a percentage of the area
between the baffle and the heat exchanger tube.
[0145] Embodiment 53: The baffle assembly or the heat exchanger of
any of the preceding embodiments, wherein a tube seal provided
between the heat exchanger tube and the baffle allows for less than
or equal to 10 vol % of a total fluid flow traversing the baffle,
to flow between them and/or wherein a vessel seal provided between
the pressure vessel and an annular baffle allows for less than or
equal to 10 vol % of a total fluid flow traversing the baffle, to
flow between them.
[0146] Embodiment 54: A baffle assembly, such as any one of the
preceding embodiments, comprising: a first tube sheet; a second
tube sheet opposite the first sheet; a heat exchanger tube, which
connects the first tube sheet and the second tube sheet; and a
plate baffle disposed between the first tube sheet and the second
tube sheet, wherein the heat exchanger tube sealingly passes
through the plate baffle, and an annular baffle sealingly disposed
between the first tube sheet and the second tube sheet, wherein the
heat exchanger tube sealingly passes through the annular
baffle.
[0147] Embodiment 55: The baffle assembly of embodiment 54, wherein
the plate baffles and the annular baffles alternate from the first
tube sheet to the second tube sheet.
[0148] Embodiment 56: The baffle assembly of any of embodiments 1
to 55, wherein a separation distance between adjacent baffles is
between 0.2 centimeters and 5,200 centimeters.
[0149] Embodiment 57: The baffle assembly of any of embodiments 1
to 56, wherein the heat exchanger tube has a first end and an
opposite second end, wherein the first end of the heat exchanger
tube is disposed on the first tube sheet, and wherein the second
end of the heat exchanger tube is disposed on the second tube
sheet, wherein a perimeter of the first end of the heat exchanger
tube is sealingly connected to the first tube sheet, and wherein a
perimeter of the second end of the heat exchanger tube is sealingly
connected to the second tube sheet.
[0150] Embodiment 58: A method of producing radial flow in a heat
exchanger, the method comprising: providing a heat exchanger
comprising a baffle assembly, such as that of any one of
embodiments 1-57, comprising a pressure vessel shell comprising an
inlet and outlet, a baffle assembly entirely disposed in the
pressure vessel shell, the baffle assembly comprising a first tube
sheet, a second tube sheet opposite the first sheet, a heat
exchanger tube, which connects the first tube sheet and the second
tube sheet; and at least one plate baffle disposed between the
first tube sheet and the second tube sheet, wherein the heat
exchanger tube sealingly passes through the baffle; and at least
one annular baffle sealingly and/or at least one plate baffle
disposed between the first tube sheet and the second tube sheet,
wherein the heat exchanger tube sealingly passes through the
baffle; and directing a production fluid from the first inlet to
the first outlet to provide a flow of the production fluid through
the pressure vessel shell to produce the radial flow.
[0151] Embodiment 59: The method of embodiment 58, wherein the
production fluid comprises water, a substituted or unsubstituted C1
to C30 hydrocarbon, a thermal fluid, a glycol, or a combination
thereof.
[0152] The disclosure has been described with reference to the
accompanying drawings, in which various embodiments are shown. This
disclosure may, however, be embodied in many different forms, and
should not be construed as limited to the embodiments set forth
herein. Rather, these embodiments are provided so that this
disclosure will be thorough and complete, and will fully convey the
scope of the disclosure to those skilled in the art. Like reference
numerals refer to like elements throughout.
[0153] It will be understood that when an element is referred to as
being "on" another element, it can be directly on the other element
or intervening elements may be present there between. In contrast,
when an element is referred to as being "directly on" another
element, there are no intervening elements present. Also, the
element may be on an outer surface or on an inner surface of the
other element, and thus "on" may be inclusive of "in" and "on."
[0154] It will be understood that, although the terms "first,"
"second," "third," etc. may be used herein to describe various
elements, components, regions, layers, and/or sections, these
elements, components, regions, layers, and/or sections should not
be limited by these terms. These terms are only used to distinguish
one element, component, region, layer, or section from another
element, component, region, layer or section. Thus, "a first
element," "component," "region," "layer," or "section" discussed
below could be termed a second element, component, region, layer,
or section without departing from the teachings herein.
[0155] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting. As
used herein, the singular forms "a," "an," and "the" are intended
to include the plural forms, including "at least one," unless the
content clearly indicates otherwise. "Or" means "and/or." As used
herein, the term "and/or" includes any and all combinations of one
or more of the associated listed items. It will be further
understood that the terms "comprises" and/or "comprising," or
"includes," and/or "including" when used in this specification,
specify the presence of stated features, regions, integers, steps,
operations, elements, and/or components, but do not preclude the
presence or addition of one or more other features, regions,
integers, steps, operations, elements, components, and/or groups
thereof.
[0156] Furthermore, relative terms, such as "lower" or "bottom" and
"upper" or "top," may be used herein to describe one element's
relationship to another element as illustrated in the Figures. It
will be understood that relative terms are intended to encompass
different orientations of the device in addition to the orientation
depicted in the Figures. For example, if the device in one of the
figures is turned over, elements described as being on the "lower"
side of other elements would then be oriented on "upper" sides of
the other elements. The exemplary term "lower," can therefore,
encompasses both an orientation of "lower" and "upper," depending
on the particular orientation of the figure. Similarly, if the
device in one of the figures is turned over, elements described as
"below" or "beneath" other elements would then be oriented "above"
the other elements. The exemplary terms "below" or "beneath" can,
therefore, encompass both an orientation of above and below.
[0157] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which this
disclosure belongs. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and the present
disclosure, and will not be interpreted in an idealized or overly
formal sense unless expressly so defined herein.
[0158] Exemplary embodiments are described herein with reference to
cross section illustrations that are schematic illustrations of
idealized embodiments. As such, variations from the shapes of the
illustrations as a result, for example, of manufacturing techniques
and/or tolerances, are to be expected. Thus, embodiments described
herein should not be construed as limited to the particular shapes
of regions as illustrated herein but are to include deviations in
shapes that result, for example, from manufacturing. For example, a
region illustrated or described as flat may, typically, have rough
and/or nonlinear features. Moreover, sharp angles that are
illustrated may be rounded. Thus, the regions illustrated in the
figures are schematic in nature and their shapes are not intended
to illustrate the precise shape of a region and are not intended to
limit the scope of the present claims.
[0159] All cited patents, patent applications, and other references
are incorporated herein by reference in their entirety. However, if
a term in the present disclosure contradicts or conflicts with a
term in the incorporated reference, the term from the present
disclosure takes precedence over the conflicting term from the
incorporated reference.
[0160] While particular embodiments have been described,
alternatives, modifications, variations, improvements, and
substantial equivalents that are or may be presently unforeseen may
arise to applicants or others skilled in the art. Accordingly, the
appended claims as filed and as they may be amended are intended to
embrace all such alternatives, modifications variations,
improvements, and substantial equivalents.
* * * * *