METHOD FOR PRODUCING A PLATE HEAT EXCHANGER AND PLATE HEAT EXCHANGER WITH THERMOCOUPLES OR MEASURING RESISTORS

Abstract

The present invention concerns a method for producing a plate heat exchanger (1) with a multiplicity of parting sheets (20) and a multiplicity of fins (11, 12), a fin being respectively arranged between two neighboring parting sheets, wherein at least one capillary (30) with at least one thermocouple and/or measuring resistor element (40) is introduced into at least one parting sheet (20), and wherein in each case a parting plate of the multiplicity of parting plates and a fin of the multiplicity of fins are alternately arranged and are connected to one another in a material-bonding manner, and concerns a plate heat exchanger (1) produced in such a way.

Claims

1. Method for producing a plate heat exchanger (1) with a multiplicity of parting sheets (20) and a multiplicity of fins (11, 12), a fin being respectively arranged between two neighboring parting sheets, wherein at least one capillary (30) with at least one thermocouple and/or measuring resistor element (40) is introduced (103) into at least one parting sheet (20) of the multiplicity of parting sheets (20), and wherein in each case a parting plate and a fin are alternately arranged (104) and are connected to one another in a material-bonding manner (106).

2. Method according to claim 1, wherein temperature values are recorded (107) by means of the at least one thermocouple and/or measuring resistor element (40) in the at least one capillary (30) during the material-bonding connection.

3. Method according to claim 1, wherein the parting sheets (20) and the fins (11, 12) are respectively connected to one another in a material-bonding manner (106) by means of a brazing process, in particular by means of a vacuum brazing process.

4. Method according to claim 1, wherein the at least one capillary (30) is introduced (103) into a groove (23, 24) in the at least one parting sheet (20).

5. Method according to claim 1, wherein the at least one parting sheet (20) is formed from a first part-sheet (21) and a second part-sheet (22) with surfaces adjacent to one another.

6. Method according to claim 4, wherein the groove (23, 24) is introduced into at least one of the two adjacent surfaces of the first and second part-sheets (21, 22).

7. Method according to claim 1, wherein the at least one capillary (30) is formed with a thin wall (31) in a first portion (31), lying inside the at least one parting sheet (20), and/or wherein the at least one capillary (30) is encapsulated in metal (32) in a second portion (32), lying outside the at least one parting sheet (20).

8. Method according to claim 1, wherein the at least one capillary (30) is brought out from a process chamber in which the material-bonding connection is carried out.

9. Method for operating a plate heat exchanger (1), which is produced by a method according to claim 1, wherein a first fluid and a second fluid are passed through the plate heat exchanger (202) and wherein, during the operation of the plate heat exchanger (1), temperature values are recorded (203) by means of the at least one thermocouple and/or measuring resistor element (40) in the at least one capillary (30).

10. Method according to claim 9, wherein the operation of the plate heat exchanger (1) is controlled in an open-loop and/or closed-loop manner (204) in dependence on the temperature values recorded during the operation of the plate heat exchanger (1).

11. Method according to claim 9, wherein a lifetime consumption and/or a remaining lifetime of the plate heat exchanger (1) is/are determined (205) in dependence on the temperature values recorded during the operation of the plate heat exchanger (1).

12. Method according to claim 9, wherein an operating history of the plate heat exchanger (1) is determined in dependence on the temperature values recorded during the operation of the plate heat exchanger (1).

13. Plate heat exchanger (1) with a multiplicity of parting sheets (20) and a multiplicity of fins (11, 12), a fin of the multiplicity of fins being respectively arranged between two neighboring parting sheets of the multiplicity of parting sheets, at least one capillary (30) with at least one thermocouple and/or measuring resistor element (40) being arranged in at least one parting sheet (20) of the multiplicity of parting sheets.

14. Plate heat exchanger (1) according to claim 13, in which the at least one parting sheet (20) is formed from a first part-sheet (21) and a second part-sheet (22) with surfaces adjacent to one another, a groove (23, 24) having been introduced into at least one of the two adjacent surfaces of the first and second part-sheets (21, 22) and the at least one capillary (30) being arranged in the groove (23, 24).

15. Plate heat exchanger (1) according to claim 13, which is produced by a method for producing a plate heat exchanger (1) with a multiplicity of parting sheets (20) and a multiplicity of fins (11, 12), a fin being respectively arranged between two neighboring parting sheets, wherein at least one capillary (30) with at least one thermocouple and/or measuring resistor element (40) is introduced (103) into at least one parting sheet (20) of the multiplicity of parting sheets (20), and wherein in each case a parting plate and a fin are alternately arranged (104) and are connected to one another in a material-bonding manner (106).

16. Plate heat exchanger (1) according to claim 13, which is designed for the purpose of being operated by a method for producing a plate heat exchanger (1) with a multiplicity of parting sheets (20) and a multiplicity of fins (11, 12), a fin being respectively arranged between two neighboring parting sheets, wherein at least one capillary (30) with at least one thermocouple and/or measuring resistor element (40) is introduced (103) into at least one parting sheet (20) of the multiplicity of parting sheets (20), and wherein in each case a parting plate and a fin are alternately arranged (104) and are connected to one another in a material-bonding manner (106), and wherein the at least one capillary (30) is brought out from a process chamber in which the material-bonding connection is carried out, in particular with a control unit which is designed for the purpose of carrying out the method.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG. 1A schematically and perspectively shows a preferred configuration of a plate heat exchanger according to the invention before the mounting of inlet and outlet attachments. FIG. 1B schematically and perspectively shows a preferred configuration of a plate heat exchanger according to the invention after the mounting of the inlet and outlet attachments, which have been produced and can be operated according to a preferred embodiment of a method according to the invention.

[0037] FIG. 2 schematically shows a detail of a preferred configuration of a plate heat exchanger according to the invention.

[0038] FIG. 3 schematically shows a preferred embodiment of a method according to the invention as a block diagram.

EMBODIMENT(S) OF THE INVENTION

[0039] In FIG. 1, a preferred configuration of a plate heat exchanger according to the invention is illustrated schematically and perspectively and is denoted by 1.

[0040] The plate heat exchanger 1 according to FIG. 1A has a cuboidal central body 8 with a length of for example several meters and a width and height of for example approximately one meter or a few meters. The central body 8 is essentially an arrangement of alternating parting sheets 20 and fins 11, 12. The central body 8 of the plate heat exchanger 1 therefore has a multiplicity of parting sheets and a multiplicity of fins, a fin being respectively arranged between two neighboring parting sheets. Both the parting sheets and the fins may for example be produced from aluminum. To their sides, the fins 11, 12 are closed off by sidebars 4, which may likewise be produced from aluminum, so that, as a result of the stacked construction with the parting sheets 20, a side wall is formed. The outer fins (here 11) of the central body 8 are closed off by a covering 5 (outer sheet), lying parallel to the fins and the parting sheets and generally likewise of aluminum.

[0041] For producing the plate heat exchanger 1, the generally braze-clad parting sheets 20, sidebars 4 and fins (here only the fins 11 and 12 are denoted) are placed one on top of the other in a stack to form the central body 8 illustrated here, which is then brazed under a vacuum in a brazing furnace. Subsequently, the inlet and outlet attachments 6, 6a required for letting the heat-exchanging fluids in and out are mounted, as shown in FIG. 1B.

[0042] In FIG. 1B, attachments 6 and 6a can be seen on top of the central body 8, at its sides and under the central body 8. The attachments 6 and 6a that are located underneath the central body 8 and on the side facing away from the side depicted are partially concealed.

[0043] A fluid or process flow can be fed to the plate heat exchanger 1 and removed again from it through nozzles 7. The attachments 6 and 6a serve for distributing the fluid introduced through the nozzles 7 and for collecting and concentrating the fluid to be removed from the plate heat exchanger 1, the distributing and collecting taking place by way of distributor fins 3 (cf. FIG. 1A) to and from the heat exchanger fins 11, 12. Within the plate heat exchanger 1, the various flows of fluid then exchange thermal energy.

[0044] The plate heat exchanger 1 shown in FIG. 1 is designed to make flows of fluid pass by one another in separate passages for heat exchange. Some of the flows can be made to pass by one another counter-currently, others cross-currently or concurrently.

[0045] At least one capillary with at least one thermocouple or a measuring resistor element has been introduced into at least one parting sheet 20 of the multiplicity of parting sheets, as explained below with reference to FIG. 2, which schematically and perspectively shows a detail of the plate heat exchanger 1.

[0046] As can be seen in FIG. 2, fins 11 and 12 are arranged alongside a parting sheet 20. The fins 11 and 12 are only illustrated very schematically, in that the path they follow on the lower surface of the detail illustrated here is indicated. The channels formed by the fins 11 and 12 extend parallel to the portion 31, which is described below. The parting sheet 20 comprises two part-sheets 21 and 22, into which a groove 23 or 24 has respectively been introduced. In these (half-)grooves 23 and 24, a capillary 30 has been introduced into the parting sheet 20, in particular in such a way that the capillary 30 is completely enclosed or covered by the material of the first part-sheet 21 and the second part-sheet 22. It is also possible to introduce only one groove into only one of the part-sheets 21, 22, into which the capillary is then inserted. Customary parting sheets or separator plates may be used for example as part-sheets 21, 22. In particular, the capillary 30 has in this case a first portion 31 inside the parting sheet 20 and a second portion 32 outside the parting sheet 20. In the first portion 31 inside the parting sheet 20, arranged in the capillary 30 are a multiplicity of mutually spaced-apart thermocouples or measuring resistor elements 40 (thermocouple or measuring resistor element profile bar), by means of which temperature values can be recorded along the longitudinal direction of the capillary 30 within the plate heat exchanger 1. The capillary 30 is designed in particular with a thin wall in the first portion 31, or as a thin stainless steel tube, and is encapsulated in metal in the second portion 32, that is to say is encased by means of a metal or is formed as a thicker tube.

[0047] Outside the parting sheet 20, the capillary 30 is brought to a transfer point 50, which may be connected by way of a cabling 51 to a computing unit 60, for example a control unit. In particular, the computing unit 60 may receive and evaluate the temperature values recorded by the thermocouples or measuring resistor elements 40 and send the result data from there, for example by means of a transmitter, to a cloud for further processing. The transfer point 50 may for example take the form of an interface between a process chamber, in which the plate heat exchanger 1 is located, and the outside world, so that in particular the computing unit 60 does not have to be arranged within the process chamber. For example, this process chamber may be a furnace or brazing furnace during a production process of the plate heat exchanger 1 or a coldbox during the regular operation of the plate heat exchanger 1.

[0048] If the measuring elements are thermocouples, the cabling must be continued in the region 51 optimally with the same material as in the region 32. Otherwise, the unit 60 cannot correctly measure the thermoelectric voltage, unless the temperature at the transfer point 50 were also measured and the thermoelectric voltage corrected correspondingly. If measuring resistor elements are used, such line connection problems can be avoided.

[0049] The plate heat exchanger 1 is produced and operated in particular according to a preferred embodiment of a method according to the invention, as explained below with reference to FIG. 3, in which a preferred embodiment of a method according to the invention is illustrated schematically as a block diagram.

[0050] A production process of the plate heat exchanger 1 is in this case denoted by 100. In the course of the production process 100, firstly, in a step 101, a multiplicity of parting sheets and a multiplicity of fins are provided.

[0051] The parting sheets correspond for example to the part-sheets 21 and 22 illustrated in FIG. 2, but in each case do not have a groove. In step 102, a groove is milled into some of the parting sheets, in order to obtain part-sheets 21 and 22 such as are illustrated in FIG. 2. For example, a groove may be respectively introduced into 25% of the multiplicity of parting sheets.

[0052] In step 103, a capillary 30 is respectively introduced in each case between two of the sheets 21, 22 provided in step 102 with grooves, in order to obtain in each case a parting sheet 20 with a capillary 30, as it is shown in FIG. 2. In this example, parting sheets 20 with a capillary 30 are therefore twice as thick as parting sheets without a capillary, since the parting sheets 20 with a capillary 30 are each produced from two such parting plates without a capillary.

[0053] In step 104, a braze is applied to the surfaces of the parting sheets in a process chamber, for example a furnace, and subsequently the parting sheets and fins are stacked alternately one on top of the other. For example, in this case every fourth parting sheet may be a parting sheet 20 with a capillary 30, so that here the parting sheets (part-sheets) adjacent to one another must be connected by brazing. After the stacking, in step 105 the individual capillaries 30 are respectively connected to a computing unit by way of a transfer point and in step 106 the parting sheets and the fins are connected to one another in a material-bonding manner in the furnace by means of brazing.

[0054] During the brazing, in step 107 temperature values within the plate heat exchanger are recorded with the aid of the thermocouples or measuring resistor elements 40 in the capillaries 30 and are transmitted to the computing unit. In step 108, the further brazing process is monitored on the basis of or in dependence on the recorded temperature values. In particular, in this case a temperature distribution in the plate heat exchanger is monitored, expediently in order to prevent the formation of gaps within the plate heat exchanger on account of different thermal expansions during the brazing operation and resultant differences in deformation due to loose or not yet sufficiently firmly connected parting sheets and fins.

[0055] When the fins and parting sheets or the part-sheets have been successfully connected to one another, in step 109 the attachments 6, 6a , nozzles 7 and covering are mounted on the plate heat exchanger 1. When the plate heat exchanger 1 has been successfully produced, the capillaries 30 can be separated from the computing unit 60 in step 110.

[0056] Even after the production process has been successfully performed, the capillaries 30 remain within the plate heat exchanger 1 and the thermocouples or measuring resistor elements 40 can also be used for recording temperature values during regular operation, as explained below.

[0057] Regular operation of the plate heat exchanger 1 is denoted in FIG. 3 by 200. In step 201, the capillaries 30 are once again connected to a computing unit, for example to a control unit. In step 202, two fluids are made to pass counter-currently through the plate heat exchanger 1, in order to perform an indirect heat exchange.

[0058] In step 203, during this operation of the plate heat exchanger, temperature values are recorded with the aid of the thermocouples or measuring resistor elements 40 in the capillaries 30. In step 204, the operation of the plate heat exchanger 1 is controlled in an open-loop or closed-loop manner in dependence on these recorded temperature values. In particular, in this case an optimization of the operation may be carried out, in order to be able to prolong the remaining lifetime of the plate heat exchanger 1.

[0059] Furthermore, in step 205 a lifetime consumption or a remaining lifetime of the plate heat exchanger 1 is determined in dependence on the recorded temperature values. For example, the temperature values can be used to determine thermal or mechanical stresses within the plate heat exchanger 1, in dependence on which the lifetime consumption and the remaining lifetime of the plate heat exchanger 1 can be determined.

[0060] In step 206, the recorded temperature values are expediently archived in the computing unit, in order to be available for a comparison with temperature values recorded at a later time.

[0061] It is consequently made possible by the present invention to carry out a temperature recording in the course of the production process of the plate heat exchanger 1, during the brazing of the fins and the parting sheets, and also in the course of the regular operation of the plate heat exchanger 1 with the same temperature measuring devices in the form of the thermocouples or measuring resistor elements 40 in capillaries 30. The thermocouples or measuring resistor elements 40 that are used in the course of the production process for monitoring the brazing can also continue to be used in regular operation.

LIST OF REFERENCE SIGNS

[0062] 1 Plate heat exchanger [0063] 3 Distributor fins [0064] 4 Sidebars [0065] 5 Covering [0066] 6 Attachment [0067] 6a Attachment [0068] 7 Nozzles [0069] 8 Central body [0070] 11 Fin [0071] 12 Fin [0072] 20 Parting sheet [0073] 21 Part-sheet [0074] 22 Part-sheet [0075] 23 Groove [0076] 24 Groove [0077] 30 Capillary [0078] 31 First portion of the capillary [0079] 32 Second portion of the capillary [0080] 40 Thermocouple or measuring resistor element [0081] 50 Transfer point [0082] 51 Line [0083] 60 Computing unit [0084] 100 Production process [0085] 101 to 110 Method steps [0086] 200 Regular operation [0087] 201 to 206 Method steps