Water separation device for connecting to an anode module of a fuel cell system, and fuel cell system comprising such a water separation device

Abstract

The present invention provides a water separation device (110) for connecting to an anode module (100) of a fuel cell system, comprising a purge valve (301) and a drain valve (302), wherein a main body (200) which is fluidically connectable to an anode outlet of the anode module (100) is provided, said main body having a first interface (404) for the location of a valve outlet (405) of the purge valve (301) and a second interface (403) for the location of a valve outlet (406) of the drain valve (302), and a flushing channel (400), and wherein at least one heating element (202203, 203204) which is connectable to the main body (200) is provided, and a fuel cell system comprising a water separation device (110) of this type.

Description

[0001] Description

[0002] Title for connecting to an anode module of an ie comprehensive such

[0003] The present invention relates to a water separator device for connection with an anode module of a fuel cell system, and to a fuel cell system comprising such a water separator device.

[0004] State of the art

[0005] Fuel cells utilize the chemical reaction of a fuel with oxygen to produce water, thereby generating electrical energy. As a core component, fuel cells contain, in particular, the so-called membrane-electrode assembly, which is a structure consisting of an ion-conducting (usually proton-conducting) membrane and a catalytic electrode (anode and cathode) arranged on each side of the membrane.

[0006] A fuel cell typically consists of a stack of multiple membrane electrode assemblies, whose electrical outputs are additive. Separator plates are usually positioned between the individual membrane electrode assemblies to ensure the supply of operating fluids to the individual cells. These separator plates also provide an electrically conductive connection to the membrane electrode assemblies.

[0007] In the operation of a fuel cell, the fuel, in particular hydrogen or a hydrogen-containing gas mixture, is supplied to the anode and electrochemically oxidized to protons, releasing electrons. The protons are transported from the anode compartment to the cathode compartment via the electrolyte or the membrane, which provides a gas-tight and electrically insulating seal between the reaction chambers. The electrons produced at the anode are then transferred to the cathode via an electrical conductor.

[0008] During operation of the fuel cell, oxygen or an oxygen-containing gas mixture is supplied to the cathode as the cathode operating medium, causing a reduction of oxygen through the uptake of electrons. Simultaneously, in the cathode compartment, the oxygen anions react with the protons transported across the membrane to form water.

[0009] To supply a fuel cell stack with the operating fluids, it has an anode supply and a cathode supply. The anode supply has an anode inlet for feeding the anode operating fluid into the anode compartments of the fuel cell and an anode outlet for removing anode exhaust gas from the anode compartments. A recirculation line is also integrated into the anode supply to feed unused hydrogen, discharged from the fuel cell stack, back into the stack. The cathode supply has a cathode inlet for feeding the cathode operating fluid into the cathode compartments of the fuel cell and a cathode outlet for removing cathode exhaust gas from the cathode compartments.

[0010] The anode inlet and anode outlet can be combined in an anode module that is connected to the fuel cell system.

[0011] During operation of the fuel cell system, product water and nitrogen reach the anode sides of the fuel cells and eventually accumulate in the anode module, particularly in the anode outlet. This product water can impair the operation of a pumping device located in the recirculation line and can also block flow paths. Therefore, a water separator is installed downstream of the stack and upstream of the recirculation pumping device in the anode outlet. The liquid water, separated from the gaseous anode exhaust gas in the water separator, is discharged via a purge line. As the nitrogen content of the recirculated anode operating fluid increases, the amount of hydrogen available for the fuel cell reactions decreases. The recirculated anode operating fluid is therefore typically purged from the anode module at regular intervals. For this purpose, the anode module is equipped with a purge valve.

[0012] Water collected in the anode module and water separator can freeze at temperatures below freezing. This can block outlets and purge lines, hindering a cold start of the fuel cell system.

[0013] Disclosure of the invention

[0014] The present invention provides a water separation device for connection with an anode module of a fuel cell system according to claim 1, and a fuel cell system comprising such a water separation device according to claim 11.

[0015] Preferred further training courses are the subject of the subclaims.

[0016] Advantages of the invention

[0017] The underlying idea of ​​the present invention is to provide a water separator for connection to an anode module of a fuel cell system. The water separator is equipped with a drain valve and a purge valve. Anode operating medium is purged from the anode module at regular intervals via the purge valve. According to the invention, the water separator is also equipped with a base body that can be fluidically connected to an anode outlet of the anode module. This base body has a first interface, also referred to as the first valve seat, for accommodating a valve outlet of the purge valve, a second interface, also referred to as the second valve seat, for accommodating a valve outlet of the drain valve, and a purge channel. Furthermore, at least one heating element that can be connected to the base body is provided.

[0018] If water collected in the anode module and the water separator freezes at temperatures below freezing, the outlets and purge lines of the anode module can be blocked, hindering a cold start of the fuel cell system. The inventive design of a water separator with a heatable base body allows the frozen water to be removed due to optimized [missing information].

[0019] The fluid guides thaw quickly and are blown out during purging. The invention thus ensures a smooth cold start of the fuel cell system even at sub-zero temperatures.

[0020] According to a preferred embodiment of the water separator, the at least one heating element is arranged externally on the base body or, alternatively or additionally, integrated into the base body. The close coupling of the heating element to the base body or its integration therein ensures optimal heat transfer and rapid thawing of frozen water within the base body.

[0021] In one embodiment of the water separator, the heating element is arranged on the base body such that it is positioned opposite the first or second interface or the first or second valve seat. This ensures that any frozen water collected in the interfaces is quickly thawed when the fuel cell system is started up, thus preventing the valve outlets from becoming blocked.

[0022] According to a preferred embodiment of the water separator, the heating element is designed as an electric heating element, in particular as a PTC thermistor. Such heating elements, also known as PTC ceramic heating elements, have a positive temperature coefficient and ensure rapid heating with low energy consumption. Due to the self-regulation of the heating element, overheating is avoided, thus providing a robust system. According to a preferred embodiment of the water separator, the base body is made of a light metal, in particular aluminum or an aluminum alloy. Due to the good thermal conductivity of the material, in conjunction with the aforementioned heating elements, rapid heating with high energy efficiency is achieved, leading to the rapid thawing of frozen water that has collected in the base body.

[0023] An advantageous embodiment of the invention provides that the heating element is designed to be fixable to the base body. For this purpose, clamps or clips extending over the heating element and the base body are preferably provided, which securely fix the heating element in its position on the base body. The clamps can also be designed as spring clamps, which allow easy removal of the heating element, for example for replacement, while still ensuring a robust connection with the base body. The base body can have receptacles for attaching the clamps or clips, into which the clamps engage or with which they are snapped.

[0024] In another preferred embodiment of the water separator, the base body has a pocket for receiving the heating element. The heating element can be easily inserted or placed into this pocket. This arrangement of the heating element inside the base body further improves heat transfer and allows the use of smaller heating elements with respect to heat generation. This further increases energy efficiency.

[0025] According to a preferred embodiment of the water separator, at least one flushing channel is provided in the base body, which is fluidically connected to the valve outlet of the purge valve, the valve outlet of the drain valve, and a flushing line of the anode outlet. The flushing channel is positioned in the base body such that, in the installed state, it lies below the valve outlets and thus forms the lowest point for the accumulation of residual water. This provides an optimized flow path for purging and flushing within the base body. The design with a flushing channel and its arrangement in the base body increases the likelihood that residual water, which freezes in cold environments, will be located outside the valve seat after purging and purging the water separator, thus preventing the valves from becoming blocked, particularly during a cold start of the fuel cell system.This ensures that the valves can open immediately, even during a cold start of the fuel cell system.

[0026] According to a preferred embodiment of the water separator, the valve outlet of the purge valve and the valve outlet of the drain valve are each provided as horizontally extending bores in the base body, while the flushing channel extends perpendicular to the valve outlets in the base body and is designed as a blind hole. In the installed state, the flushing channel is located below the outlets in the base body. Residual liquid that accumulates in the flushing channel does not block either the purge valve or the drain valve and can be quickly thawed and blown out if it freezes.

[0027] According to a preferred embodiment of the water separator, the flushing channel has a larger diameter than the diameter of the valve outlets. Any residual water remaining after blowing can thus collect in the flushing channel and is thereby removed from the interfaces or valve seats. Blockage of the valve seats or valve outlets is thus prevented or reduced.

[0028] According to a preferred embodiment of the water separator device, at least one drain opening associated with the first or second interface is provided in the base body, which also serves to drain residual water and to keep the valve outlets clear.

[0029] The invention also relates to a fuel cell system with a water separator as described above. The fuel cell system according to the invention has optimized drainage paths for residual water occurring during purging or purging of the anode outlet and ensures, or at least enables, that neither the valve outlet of the purge valve, nor the valve outlet of the drain valve, nor the purge line of the anode outlet can be blocked by frozen residual water, even under cold start conditions. Further features and advantages of embodiments of the invention will become apparent from the following description with reference to the accompanying drawings.

[0030] Brief description of the drawings

[0031] The present invention will be explained in more detail below with reference to the exemplary embodiments shown in the schematic figures of the drawing.

[0032] They show:

[0033] Fig. 1 shows a perspective view of an anode module of the fuel cell system according to an embodiment of the present invention;

[0034] Fig. 2a shows a perspective view of a variant of the base body of the water separator device according to an embodiment of the present invention;

[0035] Fig. 2b shows a perspective view of a variant of the base body of the water separator device according to a further embodiment of the present invention;

[0036] Fig. 3 shows a perspective view of a variant of the base body of the water separator device according to a further embodiment of the present invention;

[0037] Fig. 4a-c schematic representations of the flushing channel in various possible positions of a base body of the water separator device, according to an embodiment of the present invention.

[0038] In the figures, identical reference numerals denote identical or functionally equivalent elements. Fig. 1 shows a perspective view of the anode module 100 in the fuel cell system according to an embodiment of the present invention. Associated with the anode module 100, and in the embodiment located below the anode module 100, is the water separator 110 with a base body 200 attached to it. The base body 200 provides a first interface 404 for a first valve seat 201 for the purge valve 301 and a second interface 403 for a second valve seat 202 for the drain valve 302. Inside the base body 200 is a purge channel 400 (not shown in Fig. 1), which is fluidically connected to the outlets 405, 406 of the purge valve 301 and the drain valve 302 on the one hand and to the purge line 500 of the anode outlet on the other.The drain valve 302 is designed to drain liquid water separated from the gaseous anode exhaust gas, while the purge valve 301 serves to purge the purge line 500. To prevent liquid or water from freezing inside the water separator 110 at temperatures below freezing point and blocking the outlets 405, 406 of purge valve 301 and drain valve 302 and / or the purge line 500, the base body 200 is designed to be heated.

[0039] Fig. 2a shows a perspective view of a variant of the base body 200 of the water separator 110 according to an embodiment of the present invention. The base body 200, which in this embodiment is made of aluminum, has locking lugs 209 arranged on its outer surface. Spring clamps 205, 206 serve to secure the heating elements 203, 204. These clamps have flanges 208 on both sides, into which recesses 210 are formed that engage with the locking lugs 209 on the base body 200. The spring clamps 205, 206 engage the heating elements 203, 204, which in the exemplary embodiment are designed as PTC heating elements or PTC thermistors, and fix them to the outside 207 of the base body 200. Due to the thermal conductivity of the aluminum material of the base body 200, the heat energy provided by the heating elements 203, 204 is introduced into the base body 200 and heats it.Liquid collected and frozen in the base body 200 is quickly thawed and can be blown out or flow towards the flushing line 500. In any case, blockage of the flushing channel 400 inside the base body 200 and the valve outlets 405, 406 of the purge valve 301 and the drain valve 302 opening into it by frozen liquid is prevented or reduced. In the embodiment shown in Fig. 2a, a total of two heating elements 203, 204 are provided, each arranged opposite the valve seats 201, 202 on the base body 200 and fixed by independent spring clamps 205, 206.

[0040] Fig. 2b shows another variant of the base body 200. This has an internal pocket 600 into which a heating element 203, 204 is inserted. Here, only one central heating element 203, 204 is provided, which extends over the entire width of the base body 200 and heats both the area of ​​the valve seats 201, 202 of the purge valve 301 and the drain valve 302 opposite the heating element 203, 204, and the flushing channel 400 located below them inside the base body 200. Since the base body 200 is also made of aluminum here, and the heating element 203, 204 is contained within the base body 200, it can be designed with a lower heating capacity.

[0041] Fig. 3 shows a transparent view of the base body 200, i.e., the area that includes the valve seats 201 and 203 for the purge valve 301 and the drain valve 302. Fig. 3 also shows the flow paths within the base body 200.

[0042] The outlets 405, 406 of the drain valve 302 and the purge valve 301 are realized via short, horizontal bores 407, 408 in the base body 200. The outlets 405, 406 connect the base body 200 to the purge valve 301 and the drain valve 302, respectively, which are arranged externally on the base body 200. The valve seats 201, 202 of the purge valve 301 and the drain valve 302, and the interfaces 403, 404 between the valves and the base body 200, are designed such that only small amounts of liquid remain in them after emptying and purging. To drain this fluid, drain openings 409, 410 are provided in the valve seats 201, 202, which are located at the lowest possible point of the respective valve seats 201, 202.The purge channel 400, which spans both valve seats 201 and 202, is deeper than the valve seats 201 and 202 located in the base body 200 and has a significantly larger diameter than the respective outlets 405 and 406 that open into the purge channel 400. The purge valve 301 and the drain valve 302 are arranged so that purging can occur primarily via the drain valve 302. The heating capability of the base body 200 effectively prevents freezing in the area of ​​the purge channel 400. The base body 200 is designed such that the lowest point where residual liquid 413 can collect is located, in any inclined position, either in the purge channel 400 of the base body 200 or in a purge line 500 arranged as an extension of the purge channel 400. Since the entire base body 200 is heated, any residual liquid 413 that accumulates in the valve seats 201, 202 or the flushing channel 400 can be effectively thawed in the event of freezing.

[0043] Figures 4a-c schematically depict the flushing channel 400 in the base body 200 of the water separator 110. Figure 4a shows a horizontal orientation of the flushing channel 400, while Figures 4b and 4c show inclined orientations. In Figure 4b, the flushing channel 400 is inclined towards the flushing line 500, which is also shown, while Figure 4c shows a variant inclined in the opposite direction. The flushing channel 400 is provided as a blind hole in the base body 200 and is fluidically connected to the outlets 405 and 406 of the purge valve 301 and the drain valve 302, which are located above the flushing channel 400. In the exemplary embodiment, the outlet 406 of the drain valve 302 is located in the rear, closed area 411 of the flushing channel 400, which is designed as a blind hole bore in the base body 200, while the outlet 405 of the purge valve 301 opens into the flushing channel 400 closer to the connection point 412 of flushing channel 400 and flushing line 500.

[0044] The purge valve 301 and the drain valve 302 are arranged such that the purge channel 400 is not blocked by liquid after emptying and purging. This is also the case in the inclined states of the base body 200 shown in Figures 4b and 4c. For this purpose, the position of the purge valve 301 is chosen such that residual liquid is always located at the lowest point of the base body 200 or outside the base body 200, even in the tilted state. As shown in Figure 4c, residual liquid 413 collects in the position of the base body inclined away from the purge line 500.

[0045] 200 rear area 411 of the blind bore of the flushing channel 400.

[0046] As shown in Fig. 4b, the residual fluid 413 flows in the opposite direction when tilted, i.e., towards the flushing line 500, into the flushing line 500 which connects to the flushing channel 400. Since the flushing channel 400 can be heated, it is ensured that even during a cold start no frozen fluid is present in the flushing channel 400, which would prevent blowing out or flushing by blocking the outlets 405, 406.

[0047] The invention provides optimized flow paths for rinsing and purging in the base body 200. After rinsing and purging the water separator 110, residual liquid 413, which freezes in cold environments, is also located outside the valve seats 201, 202 and the interfaces 403, 404, even in the inclined positions of the base body 200 shown in Figures 4b and 4c. This allows both the purge valve 301 and the drain valve 302 to open directly during a cold start, and in particular, prevents the purge channel 400 from being blocked. This is ensured by heating the base body 200, and thus the purge channel 400 and the valve seats 201, 202 and the interfaces 403, 404, via heating elements 203, 204.

[0048] Although the present invention has been fully described above with reference to the preferred embodiment, it is not limited to this embodiment but can be modified in many different ways.

Claims

Claims 1. Water separator device (110) for connection with an anode module (100) of a fuel cell system, with a purge valve (301) and a drain valve (302), characterized by a base body (200) that can be flow-connected to an anode outlet of the anode module (100), which has a first interface (404) for arranging a valve outlet (405) of the purge valve (301) and a second interface (403) for arranging a valve outlet (406) of the drain valve (302) and a flushing channel (400) and wherein at least one heating element (203, 204) that can be connected to the base body (200) is provided.

2. Water separator device (110) according to claim 1, characterized in that the heating element (203, 204) is arranged on the outside of the base body (200) or is integrated into the base body (200) and is arranged on the base body (200) opposite the first interface (404) and the second interface (403).

3. Water separator device (110) according to one of the preceding claims, characterized in that the heating element (203, 204) is designed as an electrical heating element (203, 204), in particular as a PTC thermistor.

4. Water separator device (110) according to one of the preceding claims, characterized in that the base body (200) is made of a light metal, in particular aluminium or an aluminium alloy.

5. Water separator device (110) according to one of the preceding claims, characterized in that the heating element (203, 204) is designed to be fixable to the base body (200), wherein at least one of the A clamp or clip, in particular a spring clamp (205, 206), is provided for the heating element (203, 204) and the base body (200).

6. Water separator device (110) according to one of claims 1 to 4, characterized in that the base body (200) has at least one pocket (600) for receiving the heating element (203, 204).

7. Water separator device (110) according to one of the preceding claims, characterized in that at least one flushing channel (400) is provided in the base body (200), which is fluidly connected to the valve outlet (406) of the purge valve (301) and the valve outlet (405) of the drain valve (302) and to a flushing line (500) of the anode outlet.

8. Water separator device (110) according to one of the preceding claims, characterized in that the valve outlet (406) of the purge valve (301) and the valve outlet (405) of the drain valve (302) are each designed as horizontally extending bores (407, 408) provided in the base body (200) and the flushing channel (500) runs perpendicular to the valve outlets (405, 406) in the base body (200) below the valve outlets (405, 406).

9. Water separator device (110) according to claim 7 or 8, characterized in that the flushing channel (400) has a diameter larger than the diameters of the valve outlets (405, 406) and preferably at least one drain opening (409, 410) associated with the first or the second interface (403, 404) is provided in the base body (200).

10. Fuel cell system comprising a water separator device (110) according to any one of claims 1 to 9.

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