EVAPORATION WATER TANK FOR A FUEL CELL DEVICE AND THE USE THEREOF IN A FUEL CELL DEVICE

Abstract

An evaporation water tank for a fuel cell device may include a tank bottom, a plurality of tank side walls, and a tank cover that collectively define a collection volume for evaporation water and tank air. The plurality of tank side walls may be arranged on and project away from the tank bottom. The tank cover may be arranged a distance away from the tank bottom and on the plurality of tank side walls. The tank may also include an evaporation water inlet via which an inflow of evaporation water is flowable into the collection volume and at least one evaporation water outlet via which an outflow of evaporation water is flowable from the collection volume. The evaporation water inlet may be arranged on at least one of the plurality of tank side walls. The at least one evaporation water outlet may be arranged on the tank bottom.

Claims

1. An evaporation water tank (1) for a fuel cell device (2), particularly for a fuel cell device (2) integrated into a motor vehicle, which has a collection volume (3) for evaporation water (33) and tank air (34), which collection volume is delimited or formed by a tank bottom (4), several tank side walls (5, 6) which are respectively arranged on the tank bottom (4) and projecting away therefrom, and a tank cover (8) arranged a distance (7) away from the tank bottom (4) and on the tank side walls (5, 6), with an evaporation water inlet (9), arranged on at least one tank side wall (5, 6) of these tank side walls (5, 6), for the inflow of evaporation water (33) into the evaporation water tank (1), with at least one evaporation water outlet (10, 11), arranged on the tank bottom (4), for the outflow of evaporation water (33) from the evaporation water tank (1).

2. The evaporation water tank (1) according to claim 1, characterized in that exactly two separate evaporation water outlets (10, 11) are arranged on the tank bottom (4) of the evaporation water tank (1) for the outflow of evaporation water (33) from the evaporation water tank (1).

3. The evaporation water tank (1) according to claim 1 or 2, characterized in that the evaporation water tank (1) has a tank central axis (12) which is perpendicular to the tank bottom (4), wherein the two separate evaporation water outlets (10, 11) are spaced apart from one another in a transverse direction (13) oriented transversely with respect to the tank central axis (12).

4. The evaporation water tank (1) according to any of the preceding claims, characterized in that the evaporation water tank (1) has a tank central axis (12) which is perpendicular to the tank bottom (4), wherein at least one tank side wall (5, 6) of these tank side walls (5, 6) is arranged at an angle with respect to the tank central axis (12), or the evaporation water tank (1) has a tank central axis (12) which is perpendicular to the tank bottom (4), wherein at least two tank side walls (5, 6) of these tank side walls (5, 6) are opposite with respect to the tank central axis (12) in a transverse direction (13) oriented transversely, particularly at a right angle, as relates to the tank central axis (12), each spanning a tank side wall angle (a) between itself and the tank central axis (12) in the range from greater than or equal to 5° to less than or equal to 15°.

5. The evaporation water tank (1) according to any of the preceding claims, characterized in that the evaporation water inlet (9) is arranged below an expected evaporation water level (15) on a single tank side wall (5, 6) of these tank side walls (5, 6).

6. The evaporation water tank (1) according to any of the preceding claims, characterized in that the evaporation water tank (1) has a ventilation opening (16), through which tank air (34) from the evaporation water tank (1) can pass, for venting the evaporation water tank (1).

7. The evaporation water tank (1) according to claim 6, characterized in that the ventilation opening (16) is covered by a membrane (17) through which tank air (34) from the evaporation water tank (1) can pass.

8. The evaporation water tank (1) according to any of the preceding claims, characterized in that the tank side walls (5, 6) each have a large inner tank surface (18, 19) oriented toward the collection volume (3) that is covered or at least can be covered with evaporation water (33) and tank air (34), wherein a biocidal and/or algae-growth-inhibiting and/or antibacte-rial coating (20) is arranged on at least one of these large inner tank surfaces (18, 19).

9. The evaporation water tank (1) according to claim 8, characterized in that a respective coating (20) covers at least 20% of the respective large inner tank surfaces (18, 19), and/or a respective coating (20) covers a maximum of 90% or 95% of the respective large inner tank surfaces (18, 19), or a respective coating (20) covers the respective large inner tank surface (18, 19) over the entire surface.

10. The evaporation water tank (1) according to any of the preceding claims, characterized in that at least one tank side wall (5, 6) of these tank side walls (5, 6) has a biocidal and/or algae-growth-inhibiting and/or antibacterial substance which interacts with the evaporation water (33) collected in the evaporation water tank (1).

11. The evaporation water tank (1) according to claim 10, characterized in that the biocidal and/or algae-growth-inhibiting and/or antibacterial substance is zinc pyrite.

12. The evaporation water tank (1) according to any of the preceding claims, characterized in that the evaporation water tank (1) has a compressed air inlet (21) for compressed air to flow into the evaporation water tank (1).

13. The evaporation water tank (1) according to any of the preceding claims, characterized in that the evaporation water tank (1) has a measuring tap (22) for arranging a sensor (23).

14. A use of an evaporation water tank (1) according to any of the preceding claims in a fuel cell device (2), particularly a fuel cell device (2) for a motor vehicle.

15. The use of an evaporation water tank (1) according to claim 14, characterized in that the fuel cell device (2) has a fuel cell (24), a supply air path (25) leading to the fuel cell (24) for a cathode supply air flow (26) of water-containing supply air supplied to the fuel cell (24), and an exhaust air path (27) leading away from the fuel cell (24) for a cathode exhaust air flow (28) of water-containing exhaust air flowing out of the fuel cell (24), wherein the supply air path (25) and the exhaust air path (27) are routed through a humidifier (29) of the fuel cell device (2), which humidifier communicates fluidically with the supply air and the exhaust air for humidifying the supply air and dehumidifying the exhaust air, wherein the exhaust air path (27) is routed through a water separator (30) of the fuel cell device (2), which water separator communicates fluidically with the exhaust air for removing water from the exhaust air and for providing this water as evaporation water (33), with a heat exchanger (31) for cooling the fuel cell (24), which has an evaporative cooler (32) for cooling the heat exchanger (31), wherein the evaporative cooler (32) is assigned to the water separator (30), in a manner in which there is fluidic communication, and is supplied with evaporation water (33) by same, wherein the evaporation water tank (1) is fluidically connected between the evaporative cooler (32) and the water separator (30).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The following is shown, schematically in each case:

[0033] FIG. 1 shows a preferred exemplary embodiment of an evaporation water tank in a sectional view;

[0034] FIG. 2 shows a diagram of a further preferred exemplary embodiment of an evaporation water tank used in a fuel cell device.

DETAILED DESCRIPTION

[0035] FIG. 1 shows a preferred exemplary embodiment of an evaporation water tank, which is designated overall by the reference numeral 1 and which has a collection volume 3 for evaporation water 33 and tank air 34. The collection volume 3, which can also be referred to as the tank volume, is delimited or formed by a flat tank bottom 4, by several flat tank side walls 5, 6 which are respectively arranged on the tank bottom 4 and project away therefrom, and a tank cover 8 arranged a distance 7 away from the tank bottom 4 and on the tank side walls 5, 6. The evaporation water tank 1 also has a single evaporation water inlet 9 arranged on one tank side wall 6 of these tank side walls 5, 6 for the inflow of evaporation water 33 into the evaporation water tank 1 and two separate evaporation water outlets 10, 11 arranged on the tank bottom 4 for the outflow of evaporation water 33 from the evaporation water tank 1. This makes it possible to introduce evaporation water 33 and optionally tank air 34 through the evaporation water inlet 9 into the evaporation water tank 1 for the resupply thereof. By means of the two evaporation water outlets 10, 11, evaporation water 33 can flow out of the evaporation water tank 1 in a controlled or regulated manner. It should also be mentioned that the evaporation water inlet 9 is arranged, for example, below an expected evaporation water level 15, which is indicated by a dashed line. The evaporation water level 15 designates a plane which separates the evaporation water 33 arranged in the evaporation water tank 1 from the tank air 34 also located there.

[0036] The evaporation water tank 1 also has a tank central axis 12 which is perpendicular to the tank bottom 4 and which, for example, bisects the evaporation water tank 1 in the middle. In this case, the two separate evaporation water outlets 10, 11 and the two tank side walls 5, 6 are arranged on the tank bottom 4 in such a way that they are spaced apart from one another in a transverse direction 13 oriented at right angles to the tank central axis 12. Furthermore, the two tank side walls 5, 6 are arranged obliquely with respect to the tank central axis 12 such that a tank side wall angle α of 13°, for example, is spanned between a tank side wall 5, 6 and the tank central axis 12.

[0037] The evaporation water tank 1 has a ventilation opening 16, further above the expected evaporation water level 15, through which tank air 34 can pass for venting the evaporation water tank 1. In the present case, the ventilation opening 16 is covered by a membrane 17 which can be moved back and forth between a closed position blocking the ventilation opening 16 for tank air 34, which is indicated in FIG. 1, and at least one open position releasing the ventilation opening 16 for tank air. The membrane can be used, for example, to prevent the ingress of dirt particles into the evaporation water tank 1 through the ventilation opening 16.

[0038] FIG. 1 also shows that the two tank side walls 5, 6 each have a large inner tank surface 18, 19 oriented towards the collection volume 3 and covered with evaporation water 33 and tank air 34. A biocidal and/or algae-growth-inhibiting and/or antibacterial coating 20 is arranged on the large inner tank surface 19 of the one tank side wall 6 of these tank side walls 5, 6, which coating, for example, covers about 80% of the large inner tank surfaces 19. The other tank side wall 5 of these tank side walls 5, 6 is not equipped with such a coating 20, although this is nevertheless possible.

[0039] The evaporation water tank 1 illustrated in FIG. 1 also has, for example, a compressed air inlet 21 by means of which compressed air can be fed into the evaporation water tank 1 in order to pressurize the evaporation water 33. The supplied compressed air expediently forms tank air 34. In order to monitor and possibly influence the internal pressure set in the evaporation water tank 1, the evaporation water tank 1 according to FIG. 1 has a device, characterized as a measuring tap 22, which device enables the arrangement of a sensor 23. In the present case, it is, for all practical purposes, a pressure sensor.

[0040] FIG. 2 shows a further preferred exemplary embodiment of an evaporation water tank 1 used in a fuel cell device 2 in a diagram. The fuel cell device 2 has a fuel cell 24 which is indicated by a simple small box. Leading to the fuel cell 24 is a supply air path 25 for a cathode supply air flow 26 of supply air supplied to the fuel cell 24, which supply air contains water. The fuel cell device 2 also has an exhaust air path 27, leading away from the fuel cell 24, for a cathode exhaust air flow 28 from exhaust air flowing out of the fuel cell 24, which exhaust air contains water. Operationally, the exhaust air flowing out of the fuel cell 24 is under an absolute pressure of, for example, 0.8 to 1.5 bar or 1.8 bar to 2.5 bar or 1.5 bar to 3.0 bar. The supply air path 25 and the exhaust air path 27 are routed together through a humidifier 29 of the fuel cell device 2, which humidifier communicates fluidically with the supply air and the exhaust air, and which is also indicated by a small box and is used to humidify the supply air and dehumidify the exhaust air. Furthermore, the exhaust air path 27 is routed through a multi-part water separator 30 of the fuel cell device 2, which water separator communicates fluidically with the exhaust air for removing water from the exhaust air and for providing this water as evaporation water 33. The part of the water separator 30 arranged in the cathode exhaust air flow 28 in the direction of the fuel cell 24, upstream of the humidifier 29, is formed, for example, by a coarse water separator 35 for removing water from the exhaust air and for providing this water as evaporation water 33. The coarse water separator 35 can remove relatively large water droplets from the exhaust air, as a result of which a relatively large quantity of water or a relatively large volume of water is advantageously obtained and made available as evaporation water 33. The other part of the water separator 30, which is arranged downstream of the humidifier 29 in the direction away from the fuel cell 24, is formed, for example, by a fine water separator 36 for removing water from the exhaust air that flows out of the humidifier 29 and for providing this water as evaporation water 33. The fine water separator 36 can remove relatively small water particles and/or residual moisture from the exhaust air. As a result, this fine water separator can advantageously remove at least a relatively small quantity of water or a relatively small volume of water from the exhaust air and make it available as evaporation water 33. The fine water separator 36 offers the further advantage that the exhaust air is dehumidified in such a way that further downstream, downstream of the water separator 30, components of the fuel cell device 2 arranged in the cathode exhaust air flow 28, in particular a compressor device not explained in detail, are protected from moisture damage, in particular from the impact of droplets. FIG. 2 also shows a heat exchanger 31 which is used to cool the fuel cell 24 and has an evaporative cooler 32 which is provided for cooling the heat exchanger 31.

[0041] In the present example, the evaporative cooler 32 is assigned to the coarse water separator 35 in a fluidically communicating manner and supplied by same with evaporation water 33. The evaporation water 33 flows, for example, through an evaporation water line 37 which fluidically connects the evaporative cooler 32 to the coarse water separator 35, into which evaporation water line the evaporation water tank 1 is fluidically integrated. This makes it possible for water to be removed from the cathode exhaust air flow 28 during operation of the fuel cell device 2 by means of the coarse water separator 35 and made available as evaporation water 33, wherein this evaporation water 33 flows into the evaporation water tank 1 and is stored there in order to continuously supply the evaporative cooler 32 with a sufficient quantity of water or a sufficient water volume of evaporation water 33 for cooling the heat exchanger 31.