humidifier
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- MAHLE INT GMBH
- Filing Date
- 2026-01-21
- Publication Date
- 2026-08-03
Smart Images
Figure 2026125610000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a humidifier for a fuel cell system, in particular for humidifying a dry first gas stream with a moist second gas stream according to the generic concept of claim 1.
[0002] Such a humidifier can be used particularly in a fuel cell system for humidifying dry cathode inlet air with moist cathode outlet air. However, in principle, any other use for such a humidifier is also conceivable. For example, in the context of building air conditioning, moist building outlet air can be used to humidify dry building inlet air. The same applies to climate chambers and climate cabinets where a certain humidity with air exchange is required. Moisture, in the context of the present application, is water that can occur in liquid or gaseous or droplet or vapor form, i.e., gaseous and droplet-like. In the humidifier, water can particularly be generated by condensation, which accumulates in the housing and may freeze if the ambient temperature is correspondingly low. This may impair the functionality of the humidifier.
[0003] The type of humidifier described at the beginning is known from German Patent Application Publication No. 102021204250, and has a plastic housing. This housing has a recess at the bottom, and within the recess is a depression for collecting water generated inside the housing. Furthermore, an outlet is located inside the depression, while a water outlet for discharging water is located outside the housing, which is fluidly connected to the outlet. In this way, water collected inside the housing or in the depression is discharged from the housing through the outlet and water outlet. In this known humidifier, a heating passage is provided at the bottom of the housing, through which a heat transfer medium can flow in the area of the depression. In this way, freezing of water collected inside the housing or in the depression can be prevented. Also, frozen water present in the area of the depression can be thawed using the heating passage. The heating passage has a heat transfer medium inlet for supplying the heat transfer medium and a heat transfer medium outlet for discharging the heat transfer medium at the bottom of the housing, and is thus formed with a relatively amount of effort and is made relatively large.
[0004] The present invention addresses the challenge of providing an improved or at least alternative embodiment for the type of humidifier described above, which is particularly superior in terms of reduced effort and aims for a compact structural form.
[0005] This problem is solved by the independent claims according to the present invention. Advantageous embodiments are the subject of the dependent claims.
[0006] The present invention is based on the general idea of equipping a humidifier with an electric heating device and a metal tube connected to the heating device to transfer heat, with its outlet opening connected to the water outlet. The electric heating device requires little structural space and is relatively easy to implement. The use of a metal tube that can be heated by the heating device facilitates the transfer of heat to the water. Therefore, the electric heating device functions particularly efficiently when connected to the tube.
[0007] More specifically, it is proposed that the humidifier has a metal tube section, which forms an outlet opening on one end and a water outlet on the other, with the outlet opening being fluidly connected to the water outlet. Furthermore, the humidifier according to the present invention has an electric heating device connected to the tube section to transfer heat directly or indirectly. The tube section typically has two ends, which, according to the present invention, are structured so that one end forms an outlet opening and the other end forms a water outlet. Thus, the heat introduced into the tube section by the heating device goes directly to the outlet opening and then to the water outlet, extending within the tube section from the outlet opening to the water outlet, thereby protecting the main components that lead water out of the housing from freezing or allowing them to be easily de-iced.
[0008] In the context of this application, "structure" is synonymous with "composition" and / or "device," so the expression "structured in such a way" is synonymous with the expression "composed in such a way" and / or "adjusted in such a way."
[0009] According to an advantageous embodiment, the heating device may be specified to extend within the recess, particularly to the outlet region where the outlet opening is located, especially centrally. This allows heat to be introduced to the pipe section near the outlet opening, thereby protecting the outlet opening from freezing particularly effectively and allowing for particularly effective de-icing.
[0010] In an advantageous embodiment, the humidifier may be characterized by having a metal heating element, which is particularly directly connected on the one hand to a heating device to transfer heat, and on the other hand preferably directly connected to a tube piece to transfer heat. This allows the heating device to transfer heat directly to the heating element, and the heating element to transfer that heat directly to the tube piece. Preferably, heat conduction is generated from the heating device through the heating element to the tube piece by a heat-transmitting connection generated by direct contact, thereby allowing the heating device to work particularly efficiently with relatively little electrical energy required.
[0011] In an advantageous embodiment, the heating element may have a metal shell that forms a recess, the shell being positioned within the recess, and an outlet opening located within the shell. Water collected within the housing preferably collects within the recess. By forming a recess within the shell of the heating element, heat supply to the water collected within the recess becomes easier or more concentrated. This increases the efficiency of the heating device.
[0012] In an advantageous embodiment, a ring-shaped seal may be provided between the shell and the housing within the recess. This prevents water from entering the rear compartment on the opposite side of the recess.
[0013] In an advantageous embodiment, the heating element may be manufactured integrally with the shell, thereby specifying that the shell is formed by an integral region of the heating element. For example, the heating element is a cast part that already has a shell. Integral manufacturing can be achieved particularly inexpensively. Nevertheless, in this case, the improved heat conduction inside the integral heating element is particularly advantageous.
[0014] According to an advantageous embodiment, the heating element may have at least one metallic rib extending within the depression so as to be in direct contact with the water that collects in the depression. Ribs of this type can easily prevent the water in the depression from freezing or can easily thaw it. Heating of the heating element also heats each rib, thereby allowing heat to be easily transferred to the water through the rib.
[0015] In an advantageous embodiment, each rib can be positioned within the shell as described above. This allows the shell to transfer heat from its edges to the water in the depressions as the heating element heats, while each rib can transfer heat from the inside of the depressions to the water. This allows the heating device to function particularly efficiently.
[0016] In an advantageous embodiment, the heating element may be manufactured integrally with each rib, so that each rib is formed by a single region of the heating element. For example, the heating element may be a cast part already equipped with each rib. The integral structural form improves heat conduction into each rib.
[0017] In this case, it is particularly advantageous for the heating element to be manufactured integrally with the shell and each rib, thereby forming the shell and each rib together as a single region of the heating element. For example, the heating element is a cast part that already includes the shell and each rib.
[0018] In an advantageous embodiment, the heating element may have at least two such ribs, which are arranged and configured such that a free space is formed between them, which fluidly connects an outflow region, particularly centrally located within the recess where an outflow opening is located, to an outer region of the housing chamber located outside the recess. In the humidifier configuration, the outer region located outside the recess is located above the recess in the housing chamber. The free space formed between the two ribs forms an outflow passage that fluidly connects the outer region to the outflow region where the outflow opening is located. By heating the ribs, the water in this free space is prevented from freezing, or preferably thawed there. This allows the free space or outflow passage to be preferably de-iced during ice formation, so that the water can be quickly discharged from the housing through the free space or outflow passage.
[0019] In an advantageous embodiment, the recess may be characterized by being surrounded by a recess rim adjacent to the bottom of the housing. Advantageously, both ribs may extend, particularly parallel to each other, to or beyond the recess rim. This allows the free space or the outflow passage to extend to or beyond the recess rim, thereby enabling rapid and efficient discharge even when the water level in the housing is relatively high.
[0020] In a favorable embodiment, the heating element may have a metal tube receiving portion that opens into a recess, into which a tube piece protrudes such that the outlet opening opens in the tube receiving portion or in the recess. As a result, the heating of the heating element heats the tube receiving portion, and the tube receiving portion itself heats the tube piece. This allows the tube piece to be heated particularly efficiently in the region of the outlet opening.
[0021] In an advantageous embodiment, the tube receiver may have a female thread, and the tube piece may have a male thread that fits into this female thread, so that the tube piece is screwed into the tube receiver. This simplifies the assembly of the humidifier. At the same time, this generates good heat conduction from the heating element to the tube piece.
[0022] Basically, embodiments may be specified in which the heating element is manufactured integrally with the tube segment, thereby the tube segment being formed by an integral region of the heating element. It is clear that the integrally manufactured heating element may optionally also have the shell and / or the ribs described above. Similarly, the tube receiving portion described above may be omitted in this case.
[0023] In another advantageous embodiment, the heating element may be manufactured integrally with the tube receiving portion, thereby specifying that the tube receiving portion is formed by a single region of the heating element. The heating element may also be a cast part already provided with the tube receiving portion.
[0024] In an advantageous embodiment, the heating element may be manufactured integrally with the tube receiving portion and the shell and / or each rib, so that the tube receiving portion and the shell and / or each rib are each formed by a single region of the heating element. For example, a heating element configured as a cast part may thus comprise the tube receiving portion and the shell and / or each rib.
[0025] According to an advantageous embodiment, the heating device may have at least one PTC element connected to transfer heat to a heating element. In this case, PTC usually stands for Positive Temperature Coefficient. Such PTC elements are superior in terms of high energy efficiency.
[0026] In an advantageous embodiment, the bottom of the housing may be specified to have a through-opening in the recess, through which a tubular piece extends into the recess. This simplifies the construction of the humidifier. Additionally or alternatively, the bottom of the housing may have a connection opening in the recess, through which a heating device extends into the recess. Such measures also facilitate the realization of the humidifier.
[0027] In another advantageous embodiment, the tube piece may be sealed to the housing in a recess, particularly by a ring-shaped outer seal. Additionally or alternatively, the tube piece may be sealed to the heating element in the recess, particularly in the tube receiving portion, by a ring-shaped inner seal. Such measures can, on the one hand, prevent water from undesirably flowing out or leaking from the housing. Similarly, they prevent impurities from entering the housing.
[0028] Further important features and advantages of the present invention are described in the dependent claims, drawings, and corresponding descriptions of the drawings.
[0029] It should be understood that the above-described features and the features further described below can be used not only in each of the described combinations but also in other combinations or alone without departing from the scope of the invention defined by the claims. For example, the above-described components and the components further described below of a higher unit such as a device, an apparatus, or an assembly shown individually can form separate components or elements of this unit, or can be an integrated area or section of this unit, even if they are shown in different forms in the drawings.
[0030] Preferred embodiments of the present invention are shown in the drawings and will be described in detail in the following description. In this case, the same reference numerals are assigned to the same or similar or functionally identical components.
Brief Description of the Drawings
[0031] [Figure 1] It is a schematic cross-sectional view showing a simplified humidifier in the region of the bottom of the housing. [Figure 2] It is a schematic view showing an enlarged detail II of FIG. 1 in the region of the depression, including a heating device, a heating element, and a tube piece. [Figure 3] It is a schematic cross-sectional view taken along the cutting line III of FIG. 2. [Figure 4] It is a schematic isometric view seen from above showing the heating element together with the heating device and the tube piece. [Figure 5] It is a schematic isometric view seen from below showing the heating element together with the heating device and the tube piece.
[0032] Corresponding to Figure 1, the humidifier 1, shown only partially here, includes a plastic housing 2 having a housing bottom 3. The humidifier 1 works to humidify a dry first gas flow 4 with a moist second gas flow 5. For this purpose, a membrane block 6, shown only in a simplified manner here, can be placed inside the housing 2, or inside the housing chamber 40 surrounded by the housing 2, which allows the first gas flow 4 and the second gas flow 5 to pass through with the medium separated, and the membrane block facilitates the transfer of moisture from the second gas flow 5 to the first gas flow 4 using a membrane not shown in detail here.
[0033] A recess 7 is formed in the bottom 3 of the housing, and within the recess is a depression 8 for collecting water 9, which is generated, for example, by condensation within the housing 2, as indicated by the arrows in Figures 1 and 2. Inside the depression 8 is an outlet opening 10. Outside the housing 2 is a water outlet 11 used for discharging water 9, which is fluidly connected to the outlet opening 10 for this purpose.
[0034] The humidifier 1 shown herein further comprises a metal tube section 12 and an electric heating device 13. The tube section 12 is linearly constructed and has two tube ends 14, namely a first tube end 14.1 and a second tube end 14.2, facing opposite directions in the axial direction. The first tube end 14.1 is located inside the housing 2 and forms an outlet opening 10. The second tube end 14.2 is located outside the housing 2 and forms a water outlet 11. Inside the tube section 12 is a tube chamber 15 that fluidly connects both tube ends 14 to each other. Thus, the outlet opening 10 and the water outlet 11 are fluidly connected to each other by the tube section 12. The electric heating device 13 is connected to transfer heat to the tube section 12 directly or indirectly. The recess 8 has an outlet region 16 formed in which the outlet opening 10 is opened. The outlet region 16 is preferably located in the center of the recess 8. Additionally or alternatively, the outlet region 16 is located at or forms the lowest point of the depression 8. Preferably, the heating device 13 is configured to extend to the outlet region 16. This allows the heating device 13 to introduce heat into the pipe section 12 in the outlet region 16, i.e., relatively close to the outlet opening 10.
[0035] According to Figures 1 to 5, in the preferred embodiment illustrated herein, the humidifier 1 may further have a heating element 17 made of metal. The heating element 17 is connected on the one hand to the heating device 13 to transfer heat directly or indirectly. On the other hand, the heating element 17 is connected to the tube piece 12 to transfer heat directly or indirectly. In this case, the embodiment illustrated herein is preferred in which the heating element 17 is connected to both the heating device 13 and the tube piece 12 to transfer heat directly, respectively. This means that the heating element 17 is in direct contact with both the heating device 13 and the tube piece 12. The heating element 17 may have a metal shell 18, which is molded and positioned to form a recess 8. For this purpose, the shell 18 is located within the recess 7. Furthermore, the outlet opening 10 is located within the shell 18. The recess 8 is adjacent to the housing bottom 3 and is surrounded by a recessed edge 19 formed in the heating element 17 in this case as well. Adjacent to the recessed edge 19, the heating element 17 has a closed annular ring groove 20 radially outward, and a heating element seal 21, preferably formed in the shape of a ring, is disposed within the ring groove. The heating element seal 21 seals the heating element 17 in the recess 7 to the housing 2.
[0036] The heating element 17 further has at least one rib 22. In the illustrated example, purely illustrative and without limiting generality, just two ribs 22, namely a first rib 22.1 and a second rib 22.2, are formed on the heating element 10. Each rib 22 extends into a recess 8, that is, the rib 22 extends so as to be in contact with the water 9 possibly present in the recess 8. In the illustrated assembled state of the humidifier 1, the recess 8 is located at the bottom of the housing 2. Furthermore, the bottom of the housing 3 is inclined toward the recess 8 or recess 7, so that the water 9 generated in the housing 2 flows, due to gravity, along the bottom of the housing 3 toward the recess 7, where it reaches the recess 8. Each rib 22 is preferably configured linearly, and in the example shown here, it extends vertically. In this case, each rib 22 may start from the shell 18 and project upward from there.
[0037] According to a preferred embodiment of the humidifier 1 shown herein, at least two ribs 22 are provided, in which case both ribs 22 are arranged and configured such that a free space 23 is formed between them, which fluidly connects the outflow region 16 to an outer region 24 of the housing chamber 40, the outer region 24 located outside the recess 8 within the housing chamber 40. In the normal assembled state of the humidifier 1, this outer region 24 is located above the recess 8 and inside the housing chamber 40. The free space 23 forms an outflow passage 25 leading from the outer region 24 to the outflow region 16. In the illustrated example, the first rib 22.1 protrudes from the shell 18, while the second rib 22.2 protrudes from a pipe receiving portion 26, which will be described in more detail later. As a result, the outflow region 16 or outflow passage 25 extends below the second rib 22.2. If a sufficient amount of water accumulates in the housing 2 to the point where a water level forms above the recess 8, and the ambient temperature is sufficiently low, a corresponding amount of ice will form. This ice block will block the free space 23 and thus the outflow passage 25, and the pipe section 12 will also block the water outlet from the outflow opening 10 to the water outlet 11. The heating device 13 heats the heating element 17, which in turn heats the rib 22. This preferably thaws the free space 23, thereby releasing the blockage of the outflow passage 25. Furthermore, direct contact between the heating element 17 and the pipe section 12 heats the pipe section 12, and the ice contained within the pipe section is preferably thawed. As a result, the area extending from the outer region 24 through the free space 23 or the outflow passage 25 to the outflow region 16, and from the outflow opening 10 through the pipe section 12 to the water outlet 11, is preferentially thawed and the blockage is released. This allows a large amount of water to be discharged from the housing 2 relatively quickly. In the illustrated example, since both ribs 22 are parallel to each other and extend beyond the recessed edge 19, relatively large ice blocks can be broken up in the area of the ribs 22, and the blockage of the outflow passage 25 can be released.
[0038] The heating element 17 may further have a metal tube receiving portion 26 that opens into the recess 8. The tube piece 12 protrudes into the tube receiving portion 26 such that the outlet opening 10 opens at the tube receiving portion 26. In the illustrated example, the outlet region 16 is formed substantially within the tube receiving portion 26. In the illustrated example, it is further specified that the tube receiving portion 26 has female threads 27, while the tube piece 12 has male threads 28 that fit into these female threads. Thus, the tube piece 12 is screwed into the tube receiving portion 26. In the preferred example shown here, the heating element 17 is manufactured integrally with the shell 18, recessed edge 19, each rib 22 and the tube receiving portion 26. Thus, the shell 18, recessed edge 19, each rib 22 and the tube receiving portion 26 are each formed by an integral region of the heating element 17. This results in a high degree of integration with respect to the heating element 17, which simplifies the assembly of the humidifier 1 and reduces manufacturing costs.
[0039] According to Figures 3 and 5, the heating device 13 has at least one PTC element 29 connected to the heating element 17 to transfer heat. For this purpose, the heating device 13 may have a metal plate 30 that is in contact with the PTC element 29 via a first contact strip 31. The metal plate 30 itself is in direct and planar contact with the metal wall 32 of the heating element 17, thereby enabling large-area heat transfer between the heating device 13 and the heating element 17. Electrical contact connections of the PTC element 29 are made via the first contact strip 31 and a second contact strip 33 described above. Both contact strips 31 and 33 lead to electrical contacts 34, which are located within a connector 35 that acts as a support for the PTC element 29 and the metal plate 30.
[0040] By positioning the heating device 13 near the outlet opening 10, a stepped portion 41 is created inside the recess 8, which is higher in the height direction. This stepped portion is stepped through the metal wall 32 and transitions to the area of the recess 8 that is lower in the height direction, where the outlet region 16 and the outlet opening 10 are located. As shown in Figure 4, both ribs 22 are directly adjacent to the metal wall 32, thereby improving heat transfer to the ribs 22.
[0041] The cross-sectional view in Figure 3 includes a displacement caused by the cutting line III shown in Figure 2, which extends through the center of the heating device 13 on one side and through the center of the tube section 12 on the other. In this case, the heating device 13 is positioned slightly offset from the tube section 12 in the height direction. In the height direction, it extends vertically when the humidifier is assembled.
[0042] The housing bottom 3 has a through-opening 36 in the recess 7, as shown in Figure 3, and the tube piece 12 extends through this through-opening into the recess 8. In this case, as shown in Figure 3, the tube piece 12 is preferably sealed to the housing 2 in the recess 7 by a ring-shaped outer seal 37, and further preferably sealed to the heating element 17 in the recess 8, in this example, at the tube receiving portion 26, by a ring-shaped inner seal 38. Furthermore, the housing bottom 3 has a connection opening 39 in the recess 7, and the heating device 13 extends through the connection opening into the recess 7. Preferably, the heating device 13 or connector 35 is sealed to the housing 2 by a ring-shaped connector seal 42. [Explanation of symbols]
[0043] 1 humidifier 2 Housing 3. Bottom of the housing 4. First gas flow 5. Second gas flow 6. Membrane block 7 recesses 8. Indentation 9 water 10 Outlet opening 11 Water outlet 12 Tube piece 13 Heating device 14 Pipe end 15 Inner chamber 16 Outflow area 17 Heating element 18 shells 19 Recessed edge 20 ring grooves 21 Heating element seal 22 Ribs 23 Free space 24 Outer area 25 Outflow passage 26 Tube receiving section 27 Female thread 28 Male screw thread 29 PTC elements 30 metal plates 31. First contact strip 32 metal wall 33. Second contact strip 34. Electrical contact 35 connectors 36 Through-opening 37 Outer seal 38. Inner seal 39 Connection opening 40 Housing Interior 41 Stepped section 42 Connector seals
Claims
1. A humidifier (1) for a fuel cell system in which a dry first gas flow (4) is humidified by a moist second gas flow (5), The device has a housing (2) made of plastic, the housing having a recess (7) at the bottom (3) of the housing, and a depression (8) located within the recess for collecting water (9) generated inside the housing (2). An outflow opening (10) is located inside the recess (8). Outside the housing (2), there is a water outlet (11) for discharging water (9), which is fluidly connected to the outflow opening (10). In humidifier (1), The humidifier (1) has a metal tube piece (12), the tube piece forming the outflow opening (10) on one end and the water outlet (11) on the other end, and the outflow opening (10) is fluidly connected to the water outlet (11). The humidifier (1) has an electric heating device (13) connected to the tube section (12) to transfer heat directly or indirectly. A humidifier (1) characterized by the following.
2. The humidifier (1) according to claim 1, characterized in that the heating device (13) extends to the outlet region (16) where the outlet opening (10) is open, which is located within the recess (8).
3. The humidifier (1) according to claim 1 or 2, characterized in that the humidifier (1) has a metal heating element (17), and the heating element is connected on one side to the heating device (13) and on the other side to the tube piece (12) to transfer heat.
4. The humidifier (1) according to claim 3, characterized in that the heating element (17) has a metal shell (18) that forms the recess (8), the shell is disposed within the recess (7), and the outflow opening (10) is located within the shell.
5. The humidifier (1) according to claim 4, characterized in that the heating element (17) is manufactured integrally with the shell (18), thereby the shell (18) is formed by an integral region of the heating element (17).
6. The humidifier (1) according to any one of claims 3 to 5, characterized in that the heating element (17) has at least one metal rib (22), the rib extends within the recess (8) so as to be in direct contact with the water (9) that collects in the recess (8).
7. The humidifier (1) according to claim 6 and claim 4 or 5, characterized in that at least one such rib (22) is arranged on the shell (18).
8. The humidifier (1) according to claim 6 or 7, characterized in that the heating element (17) is manufactured integrally with each of the ribs (22), thereby each of the ribs (22) is formed by an integral region of the heating element (17).
9. The humidifier (1) according to any one of claims 6 to 8, wherein the heating element (17) has at least two such ribs (22), the ribs are arranged and configured such that a free space (23) is formed between the ribs, and the free space fluidly connects an outflow region (16) located within the recess (8) through which the outflow opening (10) is opened to an outer region (24) of the housing chamber (40) located outside the recess (8).
10. The recess (8) is surrounded by a recessed edge (19) adjacent to the housing bottom (3), The two ribs (22) extend to or beyond the recessed edge (19). A humidifier (1) according to claim 9, characterized in that it is the humidifier (1) described in claim 9.
11. The humidifier (1) according to any one of claims 3 to 10, characterized in that the heating element (17) has a metal tube receiving portion (26) that is open to the recess (8), and the tube piece (12) protrudes into the tube receiving portion such that the outflow opening (10) opens in the tube receiving portion (26) or in the recess (8).
12. The pipe receiving portion (26) has an internal screw thread (27), The tube piece (12) has a male thread (28) that fits the female thread (27), The tube piece (12) is screwed into the tube receiving portion (26). A humidifier (1) according to claim 11, characterized in that...
13. The humidifier (1) according to any one of claims 1 to 12, characterized in that the heating element (17) is manufactured integrally with the tube receiving portion (26), thereby the tube receiving portion (26) is formed by an integral region of the heating element (17).
14. The humidifier (1) according to any one of claims 3 to 13, characterized in that the heating device (13) has at least one PTC element (29) connected to the heating element (17) so as to transfer heat.
15. The housing bottom (3) has a through opening (36) in the recess (7), and the tube piece (12) extends through the through opening into the recess (8), and / or The housing bottom (3) has a connection opening (39) in the recess (7), and the heating device (13) extends into the recess (7) through the connection opening. A humidifier (1) according to any one of claims 1 to 14, characterized in that