US20140216099A1

US20140216099A1 - Method for Repairing and/or Checking an in Particular Refrigerating Installation Accommodated in a Tank Which is Closed in a Pressure-Tight Manner, and Tank for Implementing the Method

Info

Publication number: US20140216099A1
Application number: US14/118,791
Authority: US
Inventors: Remo Meister
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-05-20
Filing date: 2012-04-17
Publication date: 2014-08-07
Also published as: EP2710312B1; CH704990A1; WO2012159826A1; EP2710312A1

Abstract

Method for repairing and/or checking a refrigerating installation accommodated in a tank which is closed in a permanently pressure-tight manner, includes the steps of cutting the tank open at at least one predetermined severing location, repairing and/or checking the installation located in the tank, and closing the tank at the severing location by an integral connection.

Description

TECHNICAL FIELD

The present invention refers to the field of installation engineering. It refers to a method for repairing and/or checking in particular a refrigerating installation accommodated in a tank that is closed in a pressure-tight manner. It further refers to a tank for carrying out said method.

PRIOR ART

It has been known for a long time (see, e.g., WO 2004/020918 A1 or WO 2009/094788 A1) to structure high-power refrigerating installations in a modular manner so as to be able to respond flexibly and efficiently to different demands in terms of consumption for refrigeration. In doing so, the refrigerating installations are to be composed of usually similar refrigerating modules, each of which are encased by a protective casing in such a manner that protection between the refrigeration circuit of the individual module and the environment is provided. This protection absorbs refrigerant potentially leaking from the refrigeration circuit and prevents harmful contact between the refrigerant and the environment.
A greatly simplified diagram of such a modular refrigerating installation is represented in FIG. 7. The refrigerating installation 40 shown there is composed of a plurality of refrigerating modules KM1 . . . KMn that operate in parallel and each have a local refrigeration circuit with a compressor 38 and a heat exchanger 16. From the heat exchanger 16 of each refrigerating module KM1 . . . KMn, connecting lines are fed to the collecting lines SL1, SL2, which, for example, connect the individual modules to a refrigerating load.
Each of the individual refrigerating modules KM1 . . . KMn is now to be accommodated in a tank 10 that is closed in a pressure-tight manner and has an internal pressure (e.g. a vacuum) that differs from the outside. Such a tank that is closed in a pressure-tight manner for each refrigerating module has the followings effects:

- It ensures that in the case of leakages, no refrigerant can escape into the environment. In the case of a leakage, it shall be possible to recover the refrigerant (optionally to dispose or recycle it).
- If the refrigerant is in particular poisonous, danger to humans and animals, etc. can be ruled out without the need of further measures.
- If the refrigerant is in particular flammable or explosive, danger to humans and animals, etc. can be ruled out without the need of further measures.
- The same applies to all other types of danger to the environment, in particular to humans and animals (e.g., pressure, greenhouse effect).
- If there is a vacuum in the casing, this results in further advantages:
  - Leaking refrigerant is possibly recyclable.
  - Additional thermal insulation is not required.
  - In the case of leaking refrigerant, the installation can be turned off immediately by means of a pressure sensor, and an alarm can be output.
  - In the case of a defective casing and/or tank, likewise, a pressure increase takes place (or a pressure drop, in the case of a previous overpressure), which can turn off the installation immediately and can output an alarm.
- The casing and/or the tank can absorb and dampen vibrations and noise.
- The casing and/or the tank provide protection against mechanical damage.
- The interior of the casing and/or the tank can be cooled (if heat dissipation of the compressor becomes a problem, the interior can be kept at a desired temperature by means of tube coils or the like, e.g., by the cold return temperature or flow temperature of the medium, or by corresponding measures).

However, it is also conceivable that the casing and/or the tank is filled with a protective gas (same type of alarm as above).
The casing and/or the tank can have different designs (round, rectangular, cylindrical etc.) and can be made of different materials (stainless steel, steel, carbon, plastic, etc.), which fulfill the mentioned properties.
The tank with the module can be built as a vertical or horizontal design.
In addition to the known advantages of modular technique, the tank has the advantage that there might be no restrictions or fewer restrictions with regard to the installation site (indoor, outdoor, open to public, wall, floor, ceiling, etc.).
No specific structural safety measures are required.
No incorrect (not even unintentional) operations can take place since the entire refrigeration circuit is hermetically or semi-hermetically sealed.
In the case of damage, the modules can be replaced or can be repaired by adequate qualified personnel in an adequate environment.
The problem here is the permanent leak tightness of the tanks with the modules accommodated therein. If the tank is provided with openings that can be opened and closed again, which can be opened for repair work or an inspection, seals are required for sealing the openings. However, in order to maintain a vacuum over a long time period (>10 years), conventional rubber or plastic seals (O-rings etc.) are not sufficient due to the diffusion problems associated therewith. On the other hand, the use of metal seals is usually expensive.
The invention illustrated hereinafter therefore assumes that the modules are accommodated in tanks that are permanently closed in a gas-tight and/or pressure-tight manner.
The goal is to build such a containment tank, which shall be gas-tight under vacuum and pressure (or only pressure), in a cost-effective manner, and in the case of repair work, it shall also be possible to carry this out in a cost-effective manner.

PRESENTATION OF THE INVENTION

It is therefore an object of the invention to provide a method for repairing and/or checking in particular a refrigerating installation that is accommodated in a tank that is closed in permanently pressure-tight manner, which method can be carried out in a simple and safe manner, and wherein permanent tightness is also ensured after the repair work or check.
Furthermore, it is an object of the invention to provide a tank, in which in particular a refrigerating installation is accommodated, for carrying out the method according to the invention.
This and other objects are achieved by the features of the claims 1 and 15.
With the method according to the invention for repairing or checking a refrigerating installation accommodated in a tank that is closed in a permanently pressure-tight manner, the tank is cut open at at least one predetermined severing location, the installation accommodated in the tank is repaired and/or checked, and subsequently, the tank is closed again at the severing location by means of a firmly bonded connection.
One configuration of the method according to the invention is characterized in that by cutting open the tank, the tank is cut into at least two separate tank parts, and that after repairing the installation, the at least two separate tank parts are connected to each other again in a firmly bonded manner.
Preferably, the at least two separate tank parts are welded together.
Another configuration of the method according to the invention is characterized in that from the installation accommodated in the tank, at least one tube is fed outward through the tank wall, that for feeding through the at least one tube, the tank has a tube socket that protrudes outward from the tank wall and through which the at least one tube is fed outward, and the outside of said tube is connected to the outer end of the tube socket in a pressure-tight manner, that for repairing and/or checking the installation, the tube socket with the tube placed therein is cut through at a first predetermined severing location, and that after the repair work and/or check, the tube socket is closed again in a pressure-tight manner by a firmly bonded connection with the pipe fed therethrough.
In particular, the at least one tube is connected by a weld on the outside of the tube in pressure-tight manner to the outer end of the tube socket, wherein after the repair work and/or check, the tube socket is closed again in a pressure-tight manner by welding it to the tube fed therethrough.
Another configuration of the invention is characterized in that the at least one tube is cut through at a second severing location positioned outside the first severing location, thereby forming a gap in the tube, that for closing the gap after the repair work and/or check, the cut-off tube coming out of the tank is first moved outward through the tube socket such that it adjoins, at the second severing location, the tube part located on the outside, that then the two ends of the tube are connected to each other, and that the tube socket is closed again in a pressure-tight manner by a firmly bonded connection with the tube fed therethrough.
Preferably, the two ends of the tube are connected to each other by a weld.
According to another configuration, the at least one tube is connected to an installation part arranged in the tank, and the tube is displaced together with the installation part.
A further configuration of the method according to the invention is characterized in that the at least one tube is cut through at a second severing location positioned outside the first severing location and at a third severing location inside the tank, thereby forming a gap, that after the repair work and/or check, a suitable tube piece is inserted into the gap for closing said gap and is connected at the second and third severing locations to the ends of the tube, and that the tube socket is closed again in a pressure-tight manner by a firmly bonded connection with the inserted tube piece.
Preferably, the tube piece is connected to each of the ends of the tube by a weld.
Yet another configuration of the method according to the invention is characterized in that on the tank, an outward-facing flange connection is arranged that has a flange which is closed by a cover attached thereon, that the flange connection is surrounded by a cap which is fastened to the flange connection and closes the flange connection in a pressure-tight manner with respect to the outside, that for repairing and/or checking the installation accommodated in tank, the cap is cut open at a severing location, and that after completion of the repair work and/or check, the cap is fastened again to the flange connection in a pressure-tight manner.
A further configuration is characterized in that the flange is spaced apart from the tank wall, that a socket extending towards the tank is attached to the flange, that the cap pulled over the flange connection and the socket is connected to the free end of the socket in a firmly bonded manner, and that the connection point is severed at the severing location by simultaneously cutting through the cap and the socket.
However, it is also conceivable that the flange is spaced apart from the tank wall, that between the flange and the tank wall, a flange ring is attached that extends parallel towards the flange, that the cap pulled over the flange connection is connected to the outer edge of the flange ring in a firmly bonded manner, and that the connection point is severed at the severing location by simultaneously cutting through the cap and the flange ring.
Preferably, the cap is connected to the flange connection by a weld, and after completion of the repair work and/or check, the cap is fastened again by a weld in a pressure-tight manner to the flange connection.
The tank according to the invention, comprising in particular a refrigerating installation accommodated therein, for carrying out the method according to the invention is characterized in that the tank is closed in a gas-tight and/or pressure-tight manner by means of firmly bonded connections between its parts.
One configuration of the tank according to the invention is characterized in that from the installation accommodated in the tank, at least one tube is fed outward through the tank wall and that for feeding through the at least one tube, the tank has a tube socket that protrudes outward from the tank wall and through which the at least one tube is fed outward, and the outside of the tube is connected to the outer end of said tube socket in a pressure-tight manner.
In particular, the at least one tube is connected by a weld on the outside of the tube in a pressure-tight manner to the outer end of the tube socket.
Another configuration of the tank according to the invention is characterized in that on the tank, an outward-facing flange connection is arranged that has a flange which is closed by an cover attached thereon, and that the flange connection is surrounded by a cap which is fastened to the flange connection and closes the flange connection in a pressure-tight manner with respect to the outside.
A further configuration is characterized in that the flange is spaced apart from the tank wall, that a socket extending towards the tank is attached to the flange, and that the cap pulled over the flange connection and the socket is connected to the free end of the socket in a firmly bonded manner.
Another configuration is characterized in that the flange is spaced apart from the tank wall, that between the flange and the tank wall, a flange ring is attached that extends parallel towards the flange, and that the cap pulled over the flange connection is connected to the outer edge of the flange ring in a firmly bonded manner.
Preferably, the cap is connected to the flange connection by a weld.

BRIEF DESCRIPTION OF THE FIGURES

The invention is explained in more detail hereinafter by means of exemplary embodiments and with reference to the drawing. In the figures:

FIG. 1 shows a sectional view of an example of a permanently closed tank with a heat exchanger arranged therein and with tubes fed to the outside, wherein the tank is welded together at the severing locations from a plurality of parts;

FIG. 2 shows how the tank is opened for repairing and/or checking the installation (heat exchanger) accommodated therein, according to an exemplary embodiment of the invention, wherein a portion of the tank is severed at a severing location;

FIG. 3 shows a tank with an installation accommodated therein according to another exemplary embodiment of the invention, with a specifically formed flange connection and specifically formed tube feedthroughs (FIG. 3( b)), and how the tank is opened at a tube feedthrough (FIG. 3( c));

FIG. 4 shows a different way of opening (FIG. 4( a)) the tank at the tube feedthrough according to FIG. 3, and of closing it again (FIG. 4( b)) by feeding in the tube;

FIG. 5 shows a further way of opening (FIG. 4( a)) the tank at the tube feedthrough according to FIG. 3, and of closing it again (FIG. 4( b)) by inserting a tube piece;

FIG. 6 shows another exemplary embodiment of the flange connection on the tank (FIG. 6( a)), and the way of opening and closing it (FIG. 6( b)); and

FIG. 7 shows a greatly simplified diagram of a modularly structured refrigerating installation in which the individual modules are accommodated in each case in a permanently closed tank.

WAYS OF CARRYING OUT THE INVENTION

The center of the invention, according to FIG. 1, is a tank 10 which is closed in a permanently pressure-tight and/or gas-tight manner by means of firmly bonded connections between the parts of the tank, and which comprises in its interior 11 an installation, in particular for refrigerating (e.g., a refrigeration circuit), of which a heat exchanger 16 is exemplary illustrated in FIG. 1. The tank 10 is built from two (or more) tank parts 12, 13, and after mounting the installation or the module or the like, is connected over its circumference in a firmly bonded manner at one or more severing locations 14, 15. In the case of repair work or when checking the installation accommodated in the interior 11, which requires access to the “inner workings”, the tank is severed or cut open, for example, at the severing location 15 (FIG. 2), and after completed repair work and/or checking, is closed again.
It is most suitable with regard to tightness and stability to weld or braze the tank parts 12, 13 at the severing locations 14, 15, thus to close them by a metallic bond (however, the materials of the tank 10 are usually not exclusively steel or stainless steels).
The heat exchanger 16 of FIGS. 1 and 2 has tubes 17, 18 that are fed from the heat exchanger 16 through the wall of the tank 10 to the outside so as to be connected, for example according to FIG. 7, to common collecting lines SL1, SL2. In the example of FIGS. 1, 2, the tubes 17, 18 are fastened and sealed directly at their feedthrough through the tank wall by welds 19 and 20, respectively.
However, in order to be able in the case of repair work or waste disposal to access the “inner workings” of the refrigerating module (heat exchanger 16) and to disassemble it, if needed, a weld seam directly on the tank wall is not practicable since accessing this weld seam is very difficult.
Thus, for feeding the tubes 17 and 18 through the tank wall according to FIG. 3, advantageously, tube sockets 21, 22 protruding outward from the tank wall are provided. By first welding the tube sockets 21, 22 to the tank 10 and feeding the tubes 17, 18 of the installation parts (heat exchanger 16, etc.) accommodated in the interior 11 through these tube sockets 21, 22 and subsequently welding them together at the end of the tube sockets (welds 19 and 20), it is then possible in the event of a repair to cut open the external tube socket 21 and the tube 17 that is accommodated therein and runs to the heat exchanger 16 by means of a cutting disc or a similar tool or method at a predefined severing location 23 (FIG. 3( a, c)) and to remove and reinstall the heat exchanger 16 in a simple manner. Subsequently, the tube 17 and the tube socket 21 are connected again by a new (recessed) weld 19′ (FIG. 3( c)) at the severing location 23 in a firmly bonded and pressure-tight manner.
If by a cut through the tube 17, a gap L according to FIG. 4( b) is generated in the tube at a second severing location 23′ located farther out, the heat exchanger 16 can be “pushed forward” according to FIG. 4( b), and the still remaining shorter line of the heat exchanger 16 can be welded again to the on-site line (weld 19″) and the (shortened) tube socket 21 (weld 19′).
However—if it is not intended to push the heat exchanger 16 forward—it is also conceivable (FIG. 5) to make cuts at three severing locations 23, 23′ and 23″ of the tube (FIG. 5( a)), thereby creating a gap L′. This gap is closed again later by inserting a corresponding tube piece 34 that is connected by welds 33 and 33′ to the remaining tube ends, and to the shortened tube socket 21 by a weld 19′ (FIG. 5( b)). In this manner, the heat exchanger 16 can remain at the original position in the tank 10.
This applies to all connections between the heat exchanger 16 (or further line feedthroughs) and on-site installation parts located outside of the tank 10 which require a feedthrough through the tank wall and which cannot be accessed with tools, or can only be accessed with extreme difficulties (see the inaccessible connection 24 in FIG. 3( a)). Accessible connections (e.g. 25 in FIG. 3( a)) through which the heat exchanger 16 can be disconnected and dismantled “on the inside” are (normally, but not necessarily) implemented in the same manner; however, in this case, the line and the tube socket are not cut through, but remain in the original condition.
The previous explanations apply analogously to the closure by metallic bonding in the case of a flange connection arranged on the tank 10 (see flange connections 26 in FIGS. 3 and 26′ in FIG. 6). In this case too, opening is carried in detail in such a manner that the weld seam can simply be “cut out” with sufficient material still remaining so that a new weld seam can be applied.
The flange connection 26 in the exemplary embodiment of FIG. 3 comprises a flange 27 at the end of a tube piece protruding from the tank wall, which flange is closed through suitable screw connections with a cover 28. As is apparent from the enlarged cut-out in FIG. 3( b), a socket 30 facing towards the tank is welded to the flange 27. A cap 29 is welded (weld 31) to the free end of this socket, which cap, starting from the flange 27, encloses the flange connection 26 in a gas-tight manner. In order to remove the cap 29 and thus to get access to the flange connection 26 in the case of repair work or a check, the socket 30 and the cap 29 are cut (severed) at a severing location 32 in such a manner that the section with the weld 31 falls off. The cap 29 can then be removed and the flange connection 26 can be opened. If the flange connection 26 is subsequently to be closed again in a gas-tight manner, the cap 29 is attached and is connected at the severing location 32 to the shortened socket 30 by a new weld 31′.
An alternative exemplary embodiment for such a flange cover is illustrated in FIG. 6. The flange showed 26′ therein is covered by a cap 29′ that has a rim and is welded at the outer edge of the rim to a flange ring 37 (weld 35) which, in turn, is welded to the tube piece protruding from the tank wall. If the cap 29′ needs to be removed, the edge and the flange ring 37 are severed at a severing location 36 so that the section with the weld 35 can be removed and the cap 29′ can be taken off. When closing at a later time, the flange 37 and the cap 29′ are connected again in a gas-tight manner by a new weld 35′ (FIG. 6( b)).
With this kind of repair work, the tank 10, which is closed in a gas- and pressure-tight manner by means of firmly bonded connections between its parts, is closed again in a simple manner after the repair work. Since such a repair work and/or check is needed only very rarely, this way of opening and closing again is safer and more cost-effective than if sealed openings would be provided for this.

REFERENCE LIST

10 Tank
11 Interior
12, 13 Tank part
14, 15 Severing location
16 Heat exchanger
17, 18 Tube
19, 19′, 19″ Weld
20 Weld
21, 22 Tube socket
23, 23′, 23″ Severing location
24 Inaccessible connection
25 Accessible connection
26, 26′ Flange connection
27 Flange
28 Cover
29, 29′ Cap
30 Socket
31, 31′ Weld
32, 36 Severing location
33, 33′ Weld
34 Tube piece
35, 35′ Weld
37 Flange ring
28 Compressor
40 Refrigerating installation
KM1, KMn Refrigerating module
L, L′ Gap
SL1, SL2 Collecting line

Claims

1. A method for repairing and/or checking a refrigerating module accommodated in a tank which is closed in a permanently pressure-tight manner, wherein the refrigerating module comprises a closed local refrigeration circuit with a compressor and a heat exchanger, the method comprising:

cutting open the tank at at least one predetermined severing location,

repairing and/or checking the refrigerating module located in the tank,

and closing the tank at the severing location (14, 15; 23, 23′, 23″; 32, 36) by a firmly bonded connection.

2. The method according to claim 1, wherein, the tank is severed in at least two separate tank parts, and that after the repair of the installation, the at least two separate tank parts are connected again to each other in a firmly bonded manner.

3. The method according to claim 2, wherein the at least two separate tank parts are welded together.

4. The method according to claim 1, wherein at least one tube is fed outward through the tank wall, wherein for feeding through the at least one tube, the tank has a tube socket which protrudes outward from the tank wall and through which the at least one tube is fed outward, and the outside of the tube is connected to the outer end of said tube socket in a pressure-tight manner, wherein for repairing and/or checking the installation, the tube socket with the tube placed therein is cut through at a first predetermined severing location, and that after the repair work and/or check, the tube socket is closed again in a pressure-tight manner by a firmly bonded connection with the pipe fed therethrough.

5. The method according to claim 4, wherein the at least one tube is connected by a weld on the outside of the tube in pressure-tight manner to the outer end of the tube socket, and wherein after the repair work and/or check, the tube socket is closed again in a pressure-tight manner by welding it to the tube fed therethrough.

6. The method according to claim 4, wherein the at least one tube is cut through at a second severing location positioned outside the first severing location thereby forming a gap in the tube, wherein for closing the gap after the repair work and/or check, the cut-off tube coming out of the tank is first moved outward through the tube socket such that it adjoins, at the second severing location, the tube part located on the outside, wherein the two ends of the tube are connected to each other, and wherein the tube socket is closed again in a pressure-tight manner by a firmly bonded connection with the tube fed therethrough.

7. The method according to claim 6, wherein the two ends of the tube are connected to each other by a weld.

8. The method according to claim 6, wherein the at least one tube is connected to an installation part arranged in the tank, and wherein the tube is displaced together with the installation part.

9. The method according to claim 4, wherein the at least one tube is cut through at a second severing location positioned outside the first severing location and at a third severing location inside the tank thereby forming a gap, wherein after the repair work and/or check, a suitable tube piece is inserted into the gap for closing said gap and is connected at the second and third severing locations to the ends of the tube, and wherein the tube socket is closed again in a pressure-tight manner by a firmly bonded connection with the inserted tube piece.

10. The method according to claim 9, wherein the tube piece is connected by a weld to each of the ends of the tube.

11. The method according to claim 1, wherein on the tank, an outward-facing flange connection is arranged that has a flange which is closed by a cover attached thereon, wherein the flange connection is surrounded by a cap which is fastened to the flange connection and closes the flange connection in a pressure-tight manner with respect to the outside, wherein for repairing and/or checking the installation accommodated in tank, the cap is cut open at a severing location, and wherein after completion of the repair work and/or check, the cap is fastened again to the flange connection in a pressure-tight manner.

12. The method according to claim 11, wherein the flange is spaced apart from the tank wall, wherein a socket extending towards the tank is attached to the flange, wherein the cap pulled over the flange connection and the socket is connected to the free end of the socket in a firmly bonded manner, and wherein the connection point is severed at the severing location by simultaneously cutting through the cap and the socket.

13. The method according to claim 11, wherein the flange is spaced apart from the tank wall, wherein between the flange and the tank wall, a flange ring is attached that extends parallel towards the flange, that the cap pulled over the flange connection is connected to the outer edge of the flange ring in a firmly bonded manner, and wherein the connection point is severed at the severing location by simultaneously cutting through the cap and the flange ring.

14. The method according to claim 11, wherein the cap is connected by a weld to the flange connection, and after completion of the repair work and/or check, the cap is fastened again by a weld in a pressure-tight manner to the flange connection.

15. A tank, comprising a refrigerating module accommodated therein, wherein the refrigerating module comprises a closed local refrigeration circuit with a compressor and a heat exchanger, wherein the tank is configured for carrying out the method according to claim 1, and wherein the tank is closed in a gas-tight and/or pressure-tight manner by means of firmly bonded connections between its parts.

16. The tank according to claim 15, wherein from the installation accommodated in the tank at least one tube is fed outward through the tank wall, and wherein for feeding through the at least one tube, the tank has a tube socket which protrudes outward from the tank wall and through which the at least one tube is fed outward, and the outside of the tube is connected to the outer end of said tube socket in a pressure-tight manner.

17. The tank according to claim 16, wherein the at least one tube is connected by a weld on the outside of the tube in a pressure-tight manner to the outer end of the tube socket.

18. The tank according to claim 15, wherein on the tank, an outward-facing flange connection is arranged that has a flange which is closed by a cover attached thereon, and wherein the flange connection is surrounded by a cap which is fastened to the flange connection and closes the flange connection in a pressure-tight manner with respect to the outside.

19. The tank according to claim 18, wherein the flange is spaced apart from the tank wall, wherein a socket extending towards the tank is attached to the flange, and wherein the cap pulled over the flange connection and the socket is connected to the free end of the socket in a firmly bonded manner.

20. The tank according to claim 18, wherein the flange is spaced apart from the tank wall, wherein between the flange and the tank wall, a flange ring is attached that extends parallel towards the flange, and wherein the cap pulled over the flange connection is connected to the outer edge of the flange ring in a firmly bonded manner.

21. The tank according to claim 18, wherein the cap is connected by a weld to the flange connection.