HUMIDIFIER

Abstract

A humidifier for humidifying a dry cathode supply air via a humid cathode exhaust air in a fuel cell system, may include a housing, a membrane stack, and/or a sealing arrangement. The membrane stack may include a plurality of membranes, two first side surfaces, two second side surfaces, and/or two third side surfaces. The plurality of membranes may be stacked on one another transversely to a longitudinal direction of the membrane stack. The first side surfaces may be arranged opposite one another. The second side surfaces may be arranged opposite one another. The third side surfaces may be arranged opposite one another. The sealing arrangement may include two sealing frames, each of the sealing frames is assigned to one of the respective first side surfaces. Each of the sealing frames may have a frame-shaped contact area and a retaining edge protruding from the contact area.

Claims

1. A humidifier for humidifying a dry cathode supply air via a humid cathode exhaust air in a fuel cell system, the humidifier comprising: a housing; a membrane stack including: a plurality of membranes stacked on one another transversely to a longitudinal direction of the membrane stack; two first side surfaces through which air can flow, the first side surfaces are arranged opposite one another; two second side surfaces through which air can flow, the second side surfaces are arranged opposite one another; and two third side surfaces arranged opposite one another, wherein the first side surfaces are aligned transversely to the longitudinal direction and the second and third side surfaces are aligned parallel to the longitudinal direction; and a sealing arrangement including two sealing frames, each of the sealing frames is assigned to one of the respective first side surfaces; wherein each of the sealing frames has a frame-shaped contact area transversely to the longitudinal direction and a retaining edge protruding from the contact area in the longitudinal direction, wherein each of the sealing frames bears against one of the respective first side surfaces with the contact area at least in certain areas, and faces the membrane stack with the retaining edge; wherein the retaining edge surrounds the membrane stack at a distance, thereby forming a respective groove around the membrane stack; and wherein the respective groove is filled with an adhesive and the respective sealing frame is sealingly bonded to the membrane stack.

2. The humidifier of claim 1, wherein the membranes of the membrane stack are bonded together at an adhesive edge of the membrane stack connecting one of the respective first side surfaces and one of the respective second side surfaces; and a first adhesive area through which air cannot flow of the respective first side surface and a second adhesive area of the respective second side surface through which air cannot flow are formed on the adhesive edge of the membrane stack.

3. The humidifier of claim 2, wherein the contact area of one of the respective sealing frames covers the first adhesive area in the longitudinal direction.

4. The humidifier of claim 2, wherein the retaining edge of the respective sealing frame covers the second adhesive area transversely to the longitudinal direction.

5. The humidifier of claim 1, wherein one connecting edge of the membrane stack connecting one of the respective first side surfaces and one of the respective third side surfaces is formed by a respective edge of a respective last membrane of the membrane stack; and air can flow through the respective first side surface at the connecting edge of the membrane stack.

6. The humidifier of claim 5, wherein the contact area of the respective sealing frame does not bear against the connecting edge or solely covers the edge of the respective last membrane of the membrane stack in the longitudinal direction.

7. The humidifier of claim 5, wherein the retaining edge of the respective sealing frame at the connecting edge covers the respective third side surface transversely to the longitudinal direction.

8. The humidifier of claim 1, wherein several spacer cams facing the membrane stack are formed on the retaining edge of one of the respective sealing frames; and the respective sealing frame bears against the membrane stack with the several spacer cams, so that the respective sealing frame is centered on the membrane stack and the groove has a constant width transverse to the longitudinal direction.

9. The humidifier of claim 8, wherein the spacer cams have a smaller height from the contact area in the longitudinal direction than the retaining edge.

10. The humidifier of claim 1, wherein each of the respective sealing frames has a frame-shaped sealing area and the sealing area is fastened or formed on the contact area facing away from the membrane stack; and the sealing area sealingly bears against the housing of the humidifier and circumferentially seals the respective first side surface.

11. A humidifier, comprising: a housing; a membrane stack including: a plurality of membranes stacked on one another transversely to a longitudinal direction of the membrane stack; a first side surface through which air can flow; a second side surface through which air can flow; and a third side surface; and a sealing arrangement including a sealing frame; wherein the sealing frame has a frame-shaped contact area transversely to the longitudinal direction and a retaining edge protruding from the contact area in the longitudinal direction; wherein the sealing frame bears against the first side surface; wherein the retaining edge surrounds the membrane stack, thereby forming a groove; and wherein the groove is filled with an adhesive and the sealing frame is sealingly bonded to the membrane stack.

12. The humidifier of claim 11, wherein the membranes are bonded together at an adhesive edge of the membrane stack connecting the first side surface and the second side surface; and a first adhesive area through which air cannot flow of the first side surface and a second adhesive area of the second side surface through which air cannot flow are formed on the adhesive edge of the membrane stack.

13. The humidifier of claim 12, wherein the contact area of the sealing frame covers the first adhesive area in the longitudinal direction.

14. The humidifier of claim 12, wherein the retaining edge of the sealing frame covers the second adhesive area transversely to the longitudinal direction.

15. The humidifier of claim 11, wherein a connecting edge of the membrane stack connecting the first side surface and the third side surface is formed by an edge of a respective last membrane of the membrane stack; and air can flow through the first side surface at the connecting edge of the membrane stack.

16. The humidifier of claim 15, wherein the contact area of the sealing frame does not bear against the connecting edge or solely covers the edge of the respective last membrane of the membrane stack in the longitudinal direction.

17. The humidifier of claim 15, wherein the retaining edge of the sealing frame at the connecting edge covers the third side surface transversely to the longitudinal direction.

18. The humidifier of claim 11, wherein several spacer cams facing the membrane stack are formed on the retaining edge of the sealing frame; and the sealing frame bears against the membrane stack with the several spacer cams, so that the sealing frame is centered on the membrane stack and the groove has a constant width transverse to the longitudinal direction.

19. The humidifier of claim 18, wherein the spacer cams have a smaller height from the contact area in the longitudinal direction than the retaining edge.

20. The humidifier of claim 11, wherein the sealing frame has a frame—shaped sealing area and the sealing area is fastened or formed on the contact area facing away from the membrane stack; and the sealing area sealingly bears against the housing of the humidifier and circumferentially seals the first side surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Preferred exemplary embodiments of the invention are shown in the drawings and will be explained in more detail in the description below, where identical reference numerals denote identical or similar or functionally identical components.

[0025] In the schematic drawings:

[0026] FIG. 1 shows a view of an arrangement consisting of a membrane stack and a sealing arrangement of a humidifier according to the invention;

[0027] FIG. 2 is an exploded view of the assembly shown in FIG. 1;

[0028] FIGS. 3 and 4 show a view and a partial view of the membrane stack of the humidifier according to the invention;

[0029] FIG. 5 shows a sectional view of the arrangement shown in FIG. 1 transversely to the adhesive edges of the membrane stack;

[0030] FIG. 6 shows a sectional view of the arrangement shown in FIG. 1 transversely to the connecting edges of the membrane stack;

[0031] FIGS. 7 and 9 show different sectional views of the arrangement shown in FIG. 1 transversely to the adhesive edges of the membrane stack without an adhesive;

[0032] FIGS. 8 and 10 show different sectional views of the arrangement shown in FIG. 1 transversely to the adhesive edges of the membrane stack with an adhesive;

[0033] FIGS. 11 and 13 show different sectional views of the arrangement shown in FIG. 1 transversely to connecting edges of the membrane stack without an adhesive;

[0034] FIGS. 12 and 14 show different sectional views of the arrangement shown in FIG. 1 transversely to connecting edges of the membrane stack with an adhesive;

[0035] FIG. 15 is an exploded view of the humidifier according to the present invention.

[0036] FIG. 1 shows a view of a humidifier 1 according to the invention. The humidifier 1 is provided for humidifying a dry cathode supply air K-ZL by means of a humid cathode exhaust air K-AL in a fuel cell system.

DETAILED DESCRIPTION

[0037] The humidifier 1 comprises a membrane stack 2 and a sealing arrangement 3. In addition, the humidifier 1 comprises a housing 21 shown in FIG. 15, in which the membrane stack 2 and the sealing arrangement 3 arranged on it are accommodated. The housing 21 is not shown here for the sake of clarity.

[0038] The membrane stack 2 is cuboid and has two first side surfaces 4a and 4b, two second side surfaces 5a and 5b and two third side surfaces 6a and 6b. A longitudinal direction LR is defined in the membrane stack 2, with the first side surfaces 4a and 4b being aligned transversely to the longitudinal direction LR. The second side surfaces 5a and 5b and the third side surfaces 6a and 6b are correspondingly aligned parallel to the longitudinal direction LR. It goes without saying that the respective side surfaces 4a, 4b, 5a, 5b, 6a, 6c form a contour of the membrane stack 2 which is closed towards the outside.

[0039] The membrane stack 2 has a plurality of membranes 7 — here flat membranes — stacked transversely to the longitudinal direction LR of the membrane stack 2 at a distance from one another. As a result, in the membrane stack 2, air can flow through the first side surfaces 4a and 4b as well as through the second side surfaces 5a and 5b, whereas air cannot flow through the third side surfaces 6a and 6b or they are airtight. Supply air ducts 8 through which cathode supply air K-ZL can flow and exhaust air ducts 9 through which cathode exhaust air K-AL can flow are formed between the individual membranes 7. The membranes 7 of the membrane stack 2 are airtight and permeable to water vapor, so that the cathode supply air K-ZL and the cathode exhaust air K-AL flow through the membrane stack 2 without mixing, while the cathode supply air K-ZL within the membrane stack 2 is humidified via the membranes 7 by the cathode exhaust air K-AL. In the membrane stack 2 shown here, the dry cathode supply air K-ZL can flow through the first side surfaces 4a and 4b and the humid cathode exhaust air K-AL can flow through the second side surfaces 5a and 5b.

[0040] The sealing arrangement 3 has two sealing frames 11a and 11b, the respective sealing frame 11a or 11b being assigned to the respective first side surface 4a or 4b. The respective sealing frame 11a or 11b has a frame-shaped contact area 12, which is aligned transversely to the longitudinal direction LR, and a retaining edge 13, which protrudes from the contact area 12 in the longitudinal direction LR toward the membrane stack 2. The retaining edge 13 surrounds the contact area 12 on the outside. The contact area 12 of the respective sealing frame 11a or 11b bears against the respective first side surface 4a or 4b. The retaining edge 13 of the respective sealing frame 11a or 1 lb surrounds the membrane stack 2 at a distance, so that a circumferential groove 14a or 14b is formed between the retaining edge 13 and the membrane stack 2 in each case. The respective groove 14a or 14b is filled with an adhesive and the respective sealing frame 11a or 11b is sealingly bonded to the membrane stack. The adhesive is shapeless and forms a surrounding frame-like seal 15a or 15b after curing, which is arranged in the respective groove 14a or 14b and is integrally bonded to the membrane stack 2 and to the respective sealing frame 11a or 11b.

[0041] Moreover, the respective sealing frame 11a or 11b has a frame-like sealing area 20. The sealing area 20 is formed on the contact area 12 and faces away from the membrane stack 2 or from the retaining edge 13. If the membrane stack 2 is arranged in the housing 21—see FIG. 15—then the sealing area 20 sealingly bears against the housing and seals off the respective first side surface 4a or 4b from the remaining side surfaces within the housing 21 through which air can flow.

[0042] FIG. 2 shows an exploded view of the humidifier 1 according to the invention. In FIG. 2, the sealing frame 11a is separated from the membrane stack 2 and the sealing frame 11b is not visible. Since the two sealing frames 11a and 11b are identical to each other, the following description applies to the two sealing frames 11a and 11b. The respective sealing frame 11a or 11b has a plurality of spacer cams 16 which are formed on the retaining edge 13 of the respective sealing frame 11a or 11b. The spacer cams 16 face the membrane stack 2 and are in contact with the membrane stack 2. As a result, the respective sealing frame 11a or 11b is centered on the membrane stack 2 and the respective groove 14a or 14b has a constant width transverse to the longitudinal direction LR. The spacer cams 16 also have—measured from the contact area 12 in the longitudinal direction LR—a smaller height than the retaining edge 13. As a result, the seal 15a or 15b formed by the adhesive in the respective groove 14a or 14b is continuous all the way around.

[0043] FIG. 3 shows a view of the membrane stack 2 of the humidifier 1 according to the invention. It can be seen particularly clearly in FIG. 3 that the individual membranes 7 of the membrane stack 2 are bonded together at a total of four adhesive edges 10. The respective adhesive edge 10 is formed between the respective first side surface 4a or 4b and the respective second side surface 5a or 5b. On the respective adhesive edge 10, first adhesive areas 17 through which air cannot flow and second adhesive areas 18 through which air cannot flow are formed by the adhesive bonding of the individual membranes 7. The first adhesive areas 17 are assigned to the respective first side surface 4a or 4b and the second adhesive areas 18 are assigned to the respective second side surface 5a or 5b.

[0044] Two opposing first adhesive areas 17 are arranged on the respective first side surface 4a or 4b. Two opposite second adhesive areas 18 are arranged on the respective second side surface 5a or 5b. Air cannot flow through the adhesive areas 17 and 18 and they reduce a geometric flowable area of the respective first side surfaces 4a and 4b and of the respective second side surfaces 5a and 5b.

[0045] In addition, four connecting edges 19 are formed in the membrane stack 2 between the respective first side surface 4a or 4b and the respective third side surface 6a or 6b. The respective connecting edge 19 is formed by an edge of the respective last membrane 7 of the membrane stack 2. At the respective connecting edge 19, a geometric surface through which air can flow of the respective first side surface 4a or 4b is therefore not reduced. The respective connecting edges 19 are aligned transversely to the longitudinal direction LR. The respective first side surface 4a or 4b is assigned two connecting edges 19 lying opposite one another.

[0046] FIG. 4 shows a partial view of the membrane stack 2 of the humidifier 1 according to the invention at the adhesive edge 10. In FIG. 4, the respective first adhesive area 17 and the respective second adhesive area 18 at the respective adhesive edge 10 are particularly well visible. It can also be seen that the respective connecting edge 19 is formed by the edge of the last membrane 7 of the membrane stack 2.

[0047] FIG. 5 shows a sectional view of the membrane stack 2 with the sealing arrangement 3 transversely to the adhesive edges 10 of the membrane stack 2. In FIG. 5, the sealing frame 11a is shown and the sealing frame 11b is not visible. Since the two sealing frames 11a and 11b are identical to each other, the following description applies to the two sealing frames 11a and 11b. The contact area 12 of the respective sealing frame 11a or 11b covers only the first adhesive area 17 of the respective first side surface 4a or 4b in the longitudinal direction LR. The retaining edge 13 of the respective sealing frame 11a or 11b covers only the second adhesive area 18 of the respective second side surface 5a or 5b transversely in the longitudinal direction LR. In other words, the contact area 12 and the retaining edge 13 of the respective sealing frame 11a or 11b do not cover any areas of the respective first side surface 4a or 4b and the respective second side surface 5a or 5b through which air can flow. As a result, the flow through the membrane stack 2 on the respective first side surface 4a or 4b and the respective second side surface 5a or 5b is not negatively influenced by the sealing frame 11a or 11b.

[0048] FIG. 6 shows a sectional view of the membrane stack 2 with the sealing arrangement 3 transversely to the connecting edges 19 of the membrane stack 2. In FIG. 6 the sealing frame 11a is shown and the sealing frame 11b is not visible. Since the two sealing frames 11a and 11b are identical to each other, the following description applies to the two sealing frames 11a and 11b. The contact area 12 of the respective sealing frame 11a or 11b does not cover the respective first side surface 4a or 4b in the longitudinal direction LR. As a result, the flow through the membrane stack 2 on the respective first side surface 4a or 4b is not negatively influenced by the sealing frame 11a or 11b. However, the retaining edge 13 of the respective sealing frame 11a or 11b partially covers the respective third side surfaces 5a or 5b transversely to the longitudinal direction LR. Similarly, since air cannot flow through the respective third side surfaces 6a and 6b, the flow through the membrane stack 2 is not negatively influenced.

[0049] FIGS. 7 to 10 show different sectional views of the membrane stack 2 with the sealing arrangement 3 transversely to the adhesive edges 10. In FIGS. 7 to 10, the sealing frame 11a is shown and the sealing frame 11b is not visible. Since the two sealing frames 11a and 11b are identical to each other, the description of FIGS. 7 to 10 applies to the two sealing frames 11a and 11b.

[0050] FIG. 7 shows a sectional view of the membrane stack 2 with the sealing arrangement 3 transversely to the adhesive edges 10 of the membrane stack 2. Here, the sectional plane through the respective groove 14a or 14b lies outside of the spacer cams 16 in the respective groove 14a or 14b. The groove 14a or 14b is also shown without the adhesive and correspondingly without the respective seal 15a or 15b formed from the cured adhesive.

[0051] FIG. 8 shows a sectional view of the membrane stack 2 with the sealing arrangement 3 transversely to the adhesive edges 10 of the membrane stack 2. Here, the sectional plane through the respective groove 14a or 14b lies outside of the spacer cams 16 in the respective groove 14a or 14b. The groove 14a or 14b is also shown without the adhesive and correspondingly without the respective seal 15a or 15b formed from the cured adhesive.

[0052] FIG. 9 shows a sectional view of the membrane stack 2 with the sealing arrangement 3 transversely to the adhesive edges 10 of the membrane stack 2. Here, the sectional plane through the respective groove 14a or 14b lies through one of the spacer cams 16 in the respective groove 14a or 14b. The groove 14a or 14b is also shown without the adhesive and correspondingly without the respective seal 15a or 15b formed from the cured adhesive.

[0053] FIG. 10 shows a sectional view of the membrane stack 2 with the sealing arrangement 3 transversely to the adhesive edges 10 of the membrane stack 2. Here, the sectional plane through the respective groove 14a or 14b lies through one of the spacer cams 16 in the respective groove 14a or 14b. The groove 14a or 14b is also shown without the adhesive and correspondingly without the respective seal 15a or 15b formed from the cured adhesive.

[0054] As can be seen particularly well in FIGS. 7 to 10, the respective sealing frame 11a or 11b does not cover any areas of the respective first side surface 4a or 4b and the respective second side surface 5a or 5b through which air can flow. This does not affect the flow through the membrane stack 2. As already explained above, the respective spacer cam 16—measured from the contact area 12 in the longitudinal direction LR—also has a smaller height than the retaining edge 13 of the respective sealing frame 11a or 11b. As a result, the seal 15a or 15b formed in the groove 14a or 14b is frame-like and continuous.

[0055] FIGS. 11 to 14 show different sectional views of the membrane stack 2 with the sealing arrangement 3 transversely to the connecting edges 19. In FIGS. 11 to 14, the sealing frame 11a is shown and the sealing frame 11b is not visible. Since the two sealing frames 11a and 11b are identical to each other, the description of FIGS. 11 to 14 applies to the two sealing frames 11a and 11b.

[0056] FIG. 11 shows a sectional view of the membrane stack 2 with the sealing arrangement 3 transversely to the connecting edges 19 of the membrane stack 2. Here, the sectional plane through the respective groove 14a or 14b lies outside of the spacer cams 16 in the respective groove 14a or 14b. The groove 14a or 14b is also shown without the adhesive and correspondingly without the respective seal 15a or 15b formed from the cured adhesive.

[0057] FIG. 12 shows a sectional view of the membrane stack 2 with the sealing arrangement 3 transversely to the connecting edges 19 of the membrane stack 2. Here, the sectional plane through the respective groove 14a or 14b lies outside of the spacer cams 16 in the respective groove 14a or 14b. The groove 14a or 14b is also shown with the adhesive and correspondingly with the respective seal 15a or 15b formed from the cured adhesive.

[0058] FIG. 13 shows a sectional view of the membrane stack 2 with the sealing arrangement 3 transversely to the connecting edges 19 of the membrane stack 2. Here, the sectional plane through the respective groove 14a or 14b lies through one of the spacer cams 16 in the respective groove 14a or 14b. The groove 14a or 14b is also shown without the adhesive and correspondingly without the respective seal 15a or 15b formed from the cured adhesive.

[0059] FIG. 14 shows a sectional view of the membrane stack 2 with the sealing arrangement 3 transversely to the connecting edges 19 of the membrane stack 2. Here, the sectional plane through the respective groove 14a or 14b lies through of the spacer cams 16 in the respective groove 14a or 14b. The groove 14a or 14b is also shown with the adhesive and correspondingly with the respective seal 15a or 15b formed from the cured adhesive.

[0060] As can be seen particularly well in FIGS. 11 to 14, the respective sealing frame 11a or 11b does not cover any areas through which air can flow of the respective first side surface 4a or 4b. This does not affect the flow through the membrane stack 2 at the respective first side surfaces 4a or 4b. Air cannot flow through the respective third side surfaces 6a and 6b, so that the covering of the respective third side surface 6a or 6b with the retaining edge 13 does not affect the flow through the membrane stack 2 either. As shown in FIGS. 7 to 10, the respective spacer cam 16 in the longitudinal direction LR is smaller than the retaining edge 13 of the respective sealing frame 11a or 11b. As a result, the seal 15a or 15b formed in the groove 14a or 14b is frame-like and continuous.

[0061] FIG. 15 shows an exploded view of the humidifier 1 according to the invention. As already explained above, the humidifier has the housing 21 and the membrane stack 2 with the sealing arrangement 3 is accommodated in the housing 21. The housing 21 has a pot-shaped housing body 22 and a cover 23 that is separate from the housing body 22. The cover 23 closes the housing body 22 or an assembly opening 22 in the housing body 22 transversely to the longitudinal direction LR. The membrane stack 2 with the sealing arrangement 3 can be pushed into the housing body 22 along the longitudinal direction LR via the assembly opening 22a.

[0062] A total of four air spigots 24a, 24b and 25a, 25b are formed on the housing 21—that is, on the housing body 22 and on the cover 23. The side surfaces 4a and 4b through which air can flow can be connected via the air spigots 24a and 24b and the side surfaces 5a and 5b through which air can flow can be connected to the outside through the air spigots 25a and 25b.