U.S. patent application number 16/610205 was filed with the patent office on 2020-02-20 for cold box structure with cold box panels partly built-in and installation method therefor.
This patent application is currently assigned to L'Air Liquide, Societe Anonyme pour I'Etude et I'Exploitation des Procedes Georges Claude. The applicant listed for this patent is Alain BRIGLIA, Remy KURTZ, L'Air Liquide, Societe Anonyme pour I'Etude et I'Exploitation des Procedes Georges Claude. Invention is credited to Alain BRIGLIA, Remy KURTZ.
Application Number | 20200056840 16/610205 |
Document ID | / |
Family ID | 64015750 |
Filed Date | 2020-02-20 |
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United States Patent
Application |
20200056840 |
Kind Code |
A1 |
BRIGLIA; Alain ; et
al. |
February 20, 2020 |
COLD BOX STRUCTURE WITH COLD BOX PANELS PARTLY BUILT-IN AND
INSTALLATION METHOD THEREFOR
Abstract
Disclosed are a cold box structure with cold box panels partly
built-in and an installation method therefor. The cold box
structure is mainly applied to plate-fin heat exchangers, and in
particular to high-pressure aluminum plate-fin heat exchangers. The
cold box structure comprises a base, a cold box support frame, four
cold box panels, and a cold box top plate, and a plate-fin heat
exchanger is placed inside the cold box. Some of or all the four
cold box panels can be placed inside the cold box support frame as
needed. The cold box structure can protect the cold box support
frame from being damaged by cryogenic steam ejected from the plate
fin-heat exchanger due to leakage, and further enables the
discovering of leakage situations of the plate-fin heat exchanger
from outer surfaces of the cold box panels in a timely manner.
Inventors: |
BRIGLIA; Alain; (Hangzhou,
CN) ; KURTZ; Remy; (Hangzhou, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BRIGLIA; Alain
KURTZ; Remy
L'Air Liquide, Societe Anonyme pour I'Etude et I'Exploitation des
Procedes Georges Claude |
Houston
Houston
Paris |
TX
TX |
US
US
FR |
|
|
Assignee: |
L'Air Liquide, Societe Anonyme pour
I'Etude et I'Exploitation des Procedes Georges Claude
Paris
FR
|
Family ID: |
64015750 |
Appl. No.: |
16/610205 |
Filed: |
May 3, 2017 |
PCT Filed: |
May 3, 2017 |
PCT NO: |
PCT/CN2017/082891 |
371 Date: |
November 1, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F28F 3/02 20130101; F25J
3/04854 20130101; E04H 5/10 20130101; F25J 3/04945 20130101; F25D
3/102 20130101 |
International
Class: |
F25J 3/04 20060101
F25J003/04; E04H 5/10 20060101 E04H005/10; F28F 3/02 20060101
F28F003/02; F25D 3/10 20060101 F25D003/10 |
Claims
1-6. (canceled)
7. A cold box structure comprising a cold box support frame, four
cold box panels, a base and a cold box top plate, a plate-fin heat
exchanger being placed inside the cold box support frame, and
perlite sand being filled between the cold box and the plate-fin
heat exchanger, characterized in that the cold box panels facing
seals of the plate-fin heat exchanger are located inside the cold
box support frame.
8. The cold box structure as claimed in to claim 7, wherein the
cold box support frame and the cold box panels are made of carbon
steel or stainless steel.
9. The cold box structure as claimed in to claim 7, wherein the
cold box panels facing lateral plates of the plate-fin heat
exchanger are located outside the cold box support frame on
sides.
10. The cold box structure as claimed in to claim 7, wherein the
cold box panels facing lateral plates of the plate-fin heat
exchanger are located inside the cold box support frame on
sides.
11. An installation method applicable to the cold box structure of
claim 7, the method comprising the steps of: a. affixing a cold box
base, installing a cold box support frame, and installing a
plate-fin heat exchanger inside the cold box support frame; b.
installing four cold box panels, wherein the cold box panels facing
seals of the plate-fin heat exchanger are installed inside the cold
box support frame on sides, and the cold box panels facing lateral
plates of the plate-fin heat exchanger are installed inside or
outside the cold box support frame on sides; c. installing a cold
box top plate at the top of the cold box support frame; and d.
welding the parts of the cold box in a sealed manner, filling the
cold box with perlite sand.
12. The installation method as claimed in claim 11, wherein the
cold box panels facing the seals of the plate-fin heat exchanger
are installed in advance inside the cold box support frame on the
sides.
13. The installation method as claimed in claim 11, wherein the
cold box panels facing the seals of the plate-fin heat exchanger
are installed on-site inside the cold box support frame on the
sides.
14. The installation method as claimed in claim 11, wherein step d
further comprises charging the cold box with nitrogen after filling
the cold box with perlite sand.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a .sctn. 371 of International PCT
Application PCT/CN2017/082891, filed May 3, 2017, which is herein
incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to a cold box structure for a
plate-fin heat exchanger and an installation method therefor, which
are particularly suitable for a high-pressure aluminum plate-fin
heat exchanger.
BACKGROUND ART
[0003] The plate-fin heat exchanger has the characteristics of
compact structure, light weight, high heat transfer efficiency,
etc., and so is widely used in industrial sectors such as
refrigeration, petrochemical, air separation, aerospace, power
machinery and superconducting, and is generally recognized as one
of the new efficient heat exchangers. Due to the low-temperature
ductility and good tensile properties of aluminum alloy, plate-fin
heat exchangers made of aluminum alloy are particularly suitable
for low-temperature and ultra-low-temperature applications, and are
also widely used in air separation processes in modern industries.
At present, almost all the heat exchangers of air separation
apparatuses use plate-fin heat exchangers. Due to operating at a
temperature below -150.degree. C., the air separation apparatus
needs to be placed inside a cold box, and the cold box is filled
with perlite sand to provide heat insulation.
[0004] Generally, the cold box is in the shape of a rectangular
hexahedron, comprising a base, a cold box support frame, four cold
box panels and a cold box top plate. In the prior art, the cold box
panels are welded to the outer side the cold box support frame. The
cold box can be made of carbon steel or stainless steel, but due to
the high price of stainless steel, carbon steel is usually used in
practice. However, the carbon steel material is prone to brittle
fracture at low temperatures. In the process of air separation, if
leakage occurs at a plate-fin heat exchanger and low-temperature
steam is ejected, the perlite sand inside the cold box becomes damp
and hardened, and the cold box panels or the cold box support frame
of carbon steel is easily damaged. Failure to timely discover
leakage may result in other serious consequences.
[0005] In traditional cold box structures, the cold box panels are
placed outside the cold box support frame structure. In the process
of air separation, cryogenic steam is ejected if leakage occurs at
the plate-fin heat exchanger. If the leaked steam is directly
ejected to the cold box support frame, since the cold box panels
are located outside the cold box support frame and shield the cold
box support frame, the damage caused by the leakage is not easily
discovered in a timely manner, which may result in the failure to
timely discover leakage in the plate-fin heat exchanger. This is
not conducive to the safe operation of air separation systems,
resulting in degraded quality of air separation products, which
also may cause serious safety accidents; in addition, the repair
work for the damaged cold box support frame is huge and the cost is
high.
SUMMARY OF THE INVENTION
[0006] Certain embodiments of the present invention provide a cold
box structure with cold box panels partly built-in, which is
applicable to a plate-fin heat exchanger, and in particular to a
high-pressure aluminum plate-fin heat exchanger for use in an air
separation process. The cold box of a carbon steel material in
certain embodiments of the present invention is especially
applicable to brazed aluminum plate-fin heat exchangers with the
working pressure higher than 20 bar. Since leakage easily occurs on
the sides of the high-pressure plate-fin heat exchanger where seals
are located, and the temperature at the cold end of the heat
exchanger is -196.degree. C., cryogenic steam ejected due to
leakage seriously damages the carbon steel structure, and brittle
fracture, etc. may occur. In certain embodiments of the present
invention, cold box panels facing sides of the plate-fin heat
exchanger where the seals are located are placed inside the cold
box support frame, so that the leakage can be timely discovered
from the frost and icing conditions of the cold box panels upon
occurring, which has the function of protecting the cold box
support frame.
[0007] The technical solution adopted by at least one embodiment of
the present invention to solve the above technical problems is:
[0008] a cold box structure comprising a base, a cold box support
frame, four cold box panels and a cold box top plate, a plate-fin
heat exchanger being fixed inside the cold box, wherein the cold
box panels facing sides of the plate-fin heat exchanger where seals
are located are placed inside the cold box support frame, and
perlite sand is filled between the cold box and the plate-fin heat
exchanger.
[0009] In the present invention, the cold box support frame, the
cold box panels, and the cold box top plate may be made of carbon
steel or stainless steel.
[0010] In another embodiment of the present invention, the cold box
panels facing sides of the plate-fin heat exchanger where lateral
plates are located are placed outside the cold box support frame,
and may also be placed inside the cold box support frame.
[0011] An installation method for the cold box structure can
include the steps of:
[0012] 1) affixing a cold box base, installing a cold box support
frame, and installing a plate-fin heat exchanger inside the cold
box support frame;
[0013] 2) installing four cold box panels, wherein the cold box
panels facing seals of the plate-fin heat exchanger are installed
inside the cold box support frame, and the cold box panels facing
lateral plates of the plate-fin heat exchanger are installed inside
or outside the cold box support frame;
[0014] 3) installing a cold box top plate at the top of the cold
box support frame; and
[0015] 4) welding the parts of the cold box in a sealed manner,
filling the cold box with perlite sand, and, if necessary, charging
nitrogen.
[0016] In step 2) of the installation method, the cold box panels
facing the seals of the plate-fin heat exchanger are installed in
advance inside the cold box support frame, or are installed on-site
inside the cold box support frame, depending on the on-site
installation size.
[0017] The positive effects produced by the technical solution of
the present invention are as follows:
[0018] 1) The cold box support frame is protected. When leakage
occurs at the plate-fin heat exchanger, the leaked steam is
prevented from being directly ejected to the cold box support
frame, thereby protecting the cold box support frame from being
damaged.
[0019] 2) The leakage situation is timely discovered. The cold box
panels facing the sides of the plate-fin heat exchanger where
leakage easily occurs, that is, the sides where the seals are
located, are placed inside the cold box support frame. When leakage
occurs at the plate-fin heat exchanger, cryogenic steam is directly
ejected to the inside cold box panels. Since the cold box panels
are thin, air is condensed due to cooling, and frozen or frost
conditions of the cold box panels can also be seen from outside of
the cold box, so as to timely discover the leakage for maintenance.
If the cold box panels are placed outside the cold box support
frame, when the ejected cryogenic steam is exactly on the inside
cold box support frame, the heat transfer is slower due to the
thicker support frame, and the air is not easily condensed; in
addition, due to the shielding of the outside cold box panels, it
is difficult to discover the leakage situation of the plate-fin
heat exchanger.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Further features, advantages and possible applications of
the invention are apparent from the following description of
working and numerical examples and from the drawings. All described
and/or depicted features on their own or in any desired combination
form the subject matter of the invention, irrespective of the way
in which they are combined in the claims the way in which said
claims refer back to one another.
[0021] FIG. 1 is a schematic view of a plate-fin heat
exchanger;
[0022] FIG. 2 is a schematic structural view of a cold box support
frame;
[0023] FIG. 3 is a schematic view of the appearance of a first
embodiment of the present invention; and
[0024] FIG. 4 is a schematic view of the appearance of a second
embodiment of the present invention.
DETAILED DESCRIPTION
[0025] The specific embodiments of the present invention will be
further described below in conjunction with the accompanying
drawings.
[0026] FIG. 1 is a schematic view of a plate-fin heat exchanger,
wherein the sides on which seals of the heat exchanger are located
are faces b, b', and the sides on which lateral plates are located
are faces a, a'. A plate heat exchanger (in particular a brazed
aluminum plate heat exchanger) has a heat exchange portion inside
which a plurality of heat exchange passages are disposed. The heat
exchange passages are formed by alternately stacking partition
plates and profiled plates (for example, ribbed plates or
corrugated plates, finned plates) or distribution devices, and the
heat exchange portion is formed by heating and brazing the stack in
a suitable brazing furnace. Under high pressure, leakage easily
occurs at the brazed joint, that is, leakage easily occurs at the
faces b, b' on which the seals of the plate-fin heat exchanger are
located.
[0027] FIG. 2 shows a schematic view of a cold box support frame 2,
the four sides of which are A, A', B, B', respectively. The oblique
line areas in the figure represent the interior of the cold box
support frame on the side A' and the interior of the cold box
support frame on the side B', respectively, and 1 represents a
base. The sides B, B' of the cold box frame are opposite the sides
of the plate-fin heat exchanger where seals are located, and sides
A, A' are opposite the sides of the plate-fin heat exchanger where
cover plates are located (the plate-fin heat exchanger is not shown
in the figure). In the process of installing the cold box panels,
the cold box panels 3b, 3b' are installed inside the cold box
support frames on the sides B and B', and the cold box panels 3a,
3a' are installed outside or inside the cold box support frames on
the sides A and A'.
[0028] FIG. 3 is a first embodiment of the present invention,
comprising a base 1, a cold box support frame 2, a cold box top
plate 4, and four cold box panels 3a, 3a', 3b, 3b', wherein the
oblique line areas in the figure respectively represent the cold
box panel 3a and the cold box panel 3b (3a', 3b' are not visible in
the figure). The cold box panels 3b, 3b' are placed inside the cold
box support frame 2, and the cold box panels 3a, 3a' are placed
outside the cold box support frame 2.
[0029] Faces a and a' of the plate-fin heat exchanger are
symmetrical faces of the plate-fin heat exchanger, and faces b and
b' are further symmetrical faces of the plate-fin heat exchanger.
The sides A and A' of the cold box frame are symmetrical to each
other, and the sides B and B' are symmetrical to each other. The
cold box panels 3a and 3a' are symmetrical to each other, and 3b
and 3b' are symmetrical to each other.
[0030] In the present invention, the interior of the cold box
support frame refers to the side of the cold box support frame
facing the heat exchanger; and the exterior of the cold box support
frame refers to the side of the cold box support frame facing the
outside air.
[0031] In the present invention, the cold box panels 3a, 3a', 3b,
3b' refer to the panels on four sides of the cold box, the cold box
top plate 4 refers to the panel located at the top of the cold box,
the base 1 refers to a structure located at the bottom of the cold
box for supporting the cold box, the cold box support frame 2
refers to a structure that supports the cold box panels to fix the
cold box panels.
[0032] In the first embodiment, the cold box panels 3b, 3b' facing
the faces b, b' of the plate-fin heat exchanger are located inside
the cold box support frames on the sides B, B'. Since leakage
easily occurs at the faces b, b' of the plate-fin heat exchanger,
the cold box panels 3b, 3b' facing the faces b, b' are built inside
the cold box support frame, which can prevent leaked steam from
being directly ejected to the cold box support frame, thereby
having a protection function. In addition, the leakage can be
discovered timely. If the cold box panels 3b, 3b' are placed
outside the support frame, and if the cryogenic steam ejected due
to leakage is directly ejected to the support frame, the leakage is
not easily discovered due to the shielding of the cold box
panels.
[0033] In the first embodiment, the cold box panels 3a, 3a' facing
the faces a, a' of the plate-fin heat exchanger are located outside
the cold box support frame on the sides A, A'. Since leakage
doesn't easily occur at the faces a, a' of the plate-fin heat
exchanger, in order to reduce installation difficulty, the cold box
panels 3a, 3a' are installed outside the cold box support
frame.
[0034] FIG. 4 is a second embodiment of the present invention,
comprising a base 1, a cold box support frame 2, a cold box top
plate 4, and four cold box panels 3a, 3a', 3b, 3b', wherein the
oblique line areas in the figure respectively represent the cold
box panel 3a and the cold box panel 3b (3a', 3b' are not visible in
the figure). The four cold box panels 3a, 3a', 3b, 3b' are all
placed inside the cold box support frame 2.
[0035] In the second embodiment, the cold box structure comprises
the cold box panels 3a, 3a', 3b, 3b' placed inside the cold box
support frame, wherein the cold box panels 3a, 3a' are placed
inside the cold box support frame on sides A, A', and the cold box
panels 3b, 3b' are placed inside the cold box support frame on
sides B, B'.
[0036] In the first and second embodiments, the cold box support
frame and the cold box panels are made of carbon steel or stainless
steel.
[0037] An installation method of the cold box structure of the
first and second embodiments is as follows:
[0038] 1) fixing a cold box base 1, installing a cold box support
frame 2, and installing a plate-fin heat exchanger inside the cold
box support frame 2;
[0039] 2) installing four cold box panels 3a, 3a', 3b, 3b', wherein
the cold box panels 3b, 3b' facing seals of the plate-fin heat
exchanger are installed inside the cold box support frame on sides
B, B'. In the first embodiment, the cold box panels 3a, 3a' facing
lateral plates of the plate-fin heat exchanger are installed
outside the cold box support frame on sides A, A'; and in the
second embodiment, the cold box panels 3a, 3a' facing the lateral
plates of the plate-fin heat exchanger are installed inside the
cold box support frame on the sides A, A';
[0040] 3) installing a cold box top plate 4 at the top of the cold
box support frame 2; and
[0041] 4) welding joints in a sealed manner, filling the cold box
with perlite sand, and, if necessary, charging nitrogen.
[0042] In step 2) of the foregoing installation method, when the
installation size is limited, the cold box panels 3b, 3b' facing
the seals of the plate-fin heat exchanger may be installed in
advance inside the cold box support frame on the sides B, B'; and
if the installation size is not limited on-site, the cold box
panels 3b, 3b' may be installed on-site inside the cold box support
frame on the sides B, B'.
[0043] Of course, some equipment components or attachments, such as
pipes, cable shafts, valves or observation facilities and supports,
may be installed during factory prefabrication.
[0044] The present invention is applicable not only to rectangular
parallelepiped cold boxes but also to cylindrical cold boxes. The
present invention is also not limited to be applicable to plate-fin
heat exchangers, but to all cases where leakage can be judged by
means of the surface of the cold box, or where the cold box support
frame needs to be protected.
[0045] The above embodiments are only preferred embodiments of the
present invention, and the scope of protection of the present
invention is not limited to the embodiments. All the technical
solutions under the inventive concept are within the scope of
protection of the present invention. It should be noted that, to
those of ordinary skill in the art, several modifications and
variations without departing from the principles of the present
invention should be considered to be within the scope of protection
of the present invention.
[0046] While the invention has been described in conjunction with
specific embodiments thereof, it is evident that many alternatives,
modifications, and variations will be apparent to those skilled in
the art in light of the foregoing description. Accordingly, it is
intended to embrace all such alternatives, modifications, and
variations as fall within the spirit and broad scope of the
appended claims. The present invention may suitably comprise,
consist or consist essentially of the elements disclosed and may be
practiced in the absence of an element not disclosed. Furthermore,
if there is language referring to order, such as first and second,
it should be understood in an exemplary sense and not in a limiting
sense. For example, it can be recognized by those skilled in the
art that certain steps can be combined into a single step.
[0047] The singular forms "a", "an" and "the" include plural
referents, unless the context clearly dictates otherwise.
[0048] "Comprising" in a claim is an open transitional term which
means the subsequently identified claim elements are a nonexclusive
listing (i.e., anything else may be additionally included and
remain within the scope of "comprising"). "Comprising" as used
herein may be replaced by the more limited transitional terms
"consisting essentially of" and "consisting of" unless otherwise
indicated herein.
[0049] "Providing" in a claim is defined to mean furnishing,
supplying, making available, or preparing something. The step may
be performed by any actor in the absence of express language in the
claim to the contrary.
[0050] Optional or optionally means that the subsequently described
event or circumstances may or may not occur. The description
includes instances where the event or circumstance occurs and
instances where it does not occur.
[0051] Ranges may be expressed herein as from about one particular
value, and/or to about another particular value. When such a range
is expressed, it is to be understood that another embodiment is
from the one particular value and/or to the other particular value,
along with all combinations within said range.
[0052] All references identified herein are each hereby
incorporated by reference into this application in their
entireties, as well as for the specific information for which each
is cited.
* * * * *