DE102022203423A1 - Collector arrangement for the exhaust system of a fuel cell unit - Google Patents

Abstract

Collector arrangement for the exhaust line of a fuel cell unit The present development relates to a collector arrangement (30) for the exhaust line (40) of a fuel cell unit (10), which has a fuel cell stack (14) arranged in a fuel cell housing (12), with: - a collector body (34) which a first inlet (31) and a second inlet (32) as well as an outlet (35), the first inlet (31) and the second inlet (32) flowing into the outlet (35), - a first controllable control element ( 50, 56), which is arranged at one of the first inlet (31) and second inlet (32) to regulate the flow-through cross section of the collector body (34).

Description

Technical area

The present development relates to a fuel cell unit and a collector arrangement provided in the exhaust system of the fuel cell unit. The development also concerns a motor vehicle with such a fuel cell unit.

background

From the document DE 10 2016 118 346 A1 For example, a cathode supply for a fuel cell of a fuel cell unit is known. A cathode compressor is arranged on or in the supply path for conveying and compressing a cathode operating medium. Furthermore, the cathode supply can have a waste line, which connects the cathode supply path with a cathode exhaust path and therefore represents a cathode-side bypass for the fuel cell. Furthermore, adjusting means of the fuel cell unit are provided, which can be designed as adjustable or controllable valves, flaps, throttles or diaphragms.

In such fuel cell arrangements, it has so far been common practice to provide the individual fluid or gas-carrying paths separately with one or more actuating means or actuators. These are typically attached separately to holders and connected to each other with hoses.

In contrast, the aim of the present development is to provide a particularly favorable and practical arrangement of control elements in or on the exhaust system of a fuel cell unit, which is preferably accompanied by a reduction in the number of individual parts used and with a reduction in components. The fuel cell unit should be characterized by a comparatively simple structure. Furthermore, flow paths between the individual components of the fuel cell unit should be shortened as much as possible. The length of the lines to be laid in the area of the fuel cell unit should be shortened as much as possible and optimized in terms of their flow characteristics. Another objective is to reduce the weight and the space required for such a fuel cell unit.

Advantageous configurations

This task is solved with a collector arrangement, a fuel cell unit and with a motor vehicle with the features of the independent claims. Advantageous refinements are the subject of dependent patent claims.

In a first aspect, a collector arrangement is provided for the exhaust system of a fuel cell unit. The fuel cell unit has a fuel cell stack arranged in a fuel cell housing. The collector arrangement has a collector body. This has a first inlet and a second inlet as well as an outlet. The first inlet and the second inlet flow into the outlet in terms of flow.

The collector arrangement also has a first controllable control element, which is arranged at one of the first inlet and the second inlet to regulate the flow-through cross section of the collector body. The collector body can fluidly couple the two inlets and lead them together into the outlet. Because an actuating element is arranged at least on one of the first and second inlets, a separate fluid or gas-carrying line to or from the actuating element can advantageously be eliminated. The direct arrangement of the controllable control element on one of the first and second inlets makes it possible to regulate the flow of the line connected to the respective inlet without having to lay a separate line, such as a hose line, for this purpose.

The direct arrangement of the at least first controllable control element on one of the first and second inlets makes it possible to dispense with a separate fluid and/or gas-carrying line. The direct arrangement or even integration of the first controllable control element on or into the collector arrangement enables a reduction in the required installation space and a reduction in the number of components for the fuel cell unit.

The controllable control element can be designed, for example, as a control valve, as a control flap, as a control throttle or as a controllable aperture. The controllable control element is implemented in particular in an electronically controllable manner. For example, it can have an electromechanical drive or be mechanically coupled to one in order in particular to be able to regulate the flow-through cross section of the relevant first or second inlet as required for the operation of the fuel cell housing.

According to a further embodiment, the collector arrangement has a second controllable control element, which is arranged at the other of the first inlet and the second inlet. Typically and when implementing two actuating elements, the first actuating element is arranged at the first inlet and the second actuating element is arranged at the second inlet. The second control element can also be implemented as an electronically controllable control element, similar to the first control element. By means of the second adjusting element, for example, the cross section of the second inlet through which a medium can flow can be regulated for operating the fuel cell housing.

Because a controllable actuating element is arranged on the collector arrangement, in particular at its first and second inlets, and the collector arrangement has two separate actuating elements, the number and length of the lines to be laid can be further reduced. Furthermore, the collector body can function as a mounting platform for the first and/or the second actuating element. In this respect, the collector arrangement, in particular the collector body, has a dual function. The collector body fluidly combines the first inlet and the second inlet into the outlet.

Furthermore, the collector body can function as a mounting base for the first actuating element and/or for the second actuating element. Separate holders or support arrangements for fastening the adjusting elements on or in the fuel cell unit can therefore be omitted. This means that additional components and manufacturing costs can be saved and the weight of the fuel cell unit can also be reduced.

According to a further embodiment, the collector body has a third inlet, which can be connected or is connected to a flushing line of a flushing line of the fuel cell unit. The flushing line is typically in fluid communication with the fuel cell housing. For example, the interior of the fuel cell housing can be flushed temporarily and as needed via the flushing line, for example in order to remove excess reaction gas and/or moisture from the fuel cell housing.

The third inlet is advantageously also fluidly connected to the outlet of the collector body. The first inlet, the second inlet and the optional third inlet can be fluidically connected in parallel. Gases or fluids introduced into the collector via the corresponding inlets are combined in the collector body and led out of the collector body via the outlet. In this respect, the outlet can function as an exhaust or as a fluidic end of an exhaust system of the fuel cell unit.

According to a further embodiment, the first inlet of the collector arrangement can be fluidly coupled to an exhaust gas line of the fuel cell stack or is coupled therewith. In this respect, the first controllable actuating element can be designed as a so-called counter-pressure valve, which regulates a counter-pressure for a gas or fluid flow conducted through the fuel cell stack.

According to a further embodiment, the second inlet can be fluidly coupled to or is coupled to a bypass line surrounding the fuel cell stack. In this respect, the flow cross section can be actively controlled or regulated through a bypass line using the second controllable actuating element at the second inlet. Such a bypass line makes it possible to operate a compressor provided upstream of the fuel cell stack with a constant or predetermined volume flow and to control or regulate the volume flow to be supplied to the fuel cell stack particularly effectively, precisely and as required by adjusting the first and second actuating elements.

According to a further embodiment, the first inlet flows straight into the outlet. The second inlet opens at a predetermined angle into the first inlet and/or into the outlet of the collector body. The straight course of the first inlet makes it possible to reduce the flow resistance of the collector body between the first inlet and the outlet to a minimum. A pressure loss in the exhaust system, which extends from the fuel cell stack into the outlet, can be minimized as much as possible in this way, which is advantageous for efficient operation of the fuel cell stack.

According to a further embodiment of the collector arrangement, at least one of the first inlet and the second inlet, facing away from the collector body, has a flange section on which the first actuating element or the second actuating element can be or is arranged. A flange section in the area of the first and/or the second inlet enables a particularly simple, effective and durable and sealing connection of the respective actuating element to the relevant flange section.

In this respect, the actuating element can be or will be arranged outside and in the flow direction adjacent to the flange section or the respective first or second inlet. The actuating element can be fluidically positioned upstream of the respective inlet. The actuating element can itself have a fluid or gas-conducting housing, which is in its mounting position The flange section of the first and/or second inlet typically has a connecting piece, for example for a fluid-carrying line.

A flange section at the first and/or second inlet of the collector body enables a particularly simple and direct arrangement and sealing attachment of the first and/or second actuating element to the collector body. Any hose lines between the collector and the control elements can therefore be omitted.

According to a further embodiment, the first control element or the second control element has an electronically controllable flap arrangement, an electronically controllable throttle or an electronically controllable valve arrangement. The adjusting element is typically continuously adjustable in order to change, in particular to regulate, the cross section of the first inlet and/or the second inlet through which a gas or fluid can flow as required. Typically, the first control element and the second control element can be controlled independently of one another.

According to a further embodiment, the collector body is designed in one piece. It can be designed in the form of a cast component, for example made of metal or plastic. A one-piece or one-piece design of the collector body proves to be particularly advantageous from a cost perspective and from an assembly point of view.

According to a further aspect, the present development also relates to a fuel cell unit, in particular for a motor vehicle. The fuel cell unit has a fuel cell housing in which a fuel cell stack is arranged. The fuel cell unit also has a gas-carrying supply line which opens into the fuel cell stack. The fuel cell unit also has a gas-carrying exhaust line which leads out of the fuel cell stack. The fuel cell unit also has a previously described collector arrangement. The first inlet of the collector arrangement is fluidly connected to the fuel cell stack. The second inlet of the collector arrangement is connected to a bypass line of a bypass line. The bypass line branches off from the supply line upstream of the fuel cell stack.

The fuel cell unit equipped with the collector arrangement described above is characterized by a reduced number of components. In particular, by means of the collector arrangement, the controllable control elements can be arranged directly on the collector body, so that a separate assembly and fastening of the controllable control elements as well as their fluid connection to a collector provided at a distance therefrom can be omitted. Furthermore, the direct arrangement of one or more control elements on the collector arrangement is characterized by a reduced number of lines required, in particular hose lines.

According to a further aspect, the present development finally relates to a motor vehicle with a previously described fuel cell unit. The motor vehicle can be designed as a passenger car or as a transporter. In addition to the fuel cell unit, the motor vehicle can have a battery and an electric drive. Energy for the electric drive can be stored using the battery and generated locally using the fuel cell unit.

Short description of the characters

• 1 eine schematische Seitenansicht eines Kraftfahrzeugs,
• 2 eine perspektivische Darstellung einer Implementierung eines Brennstoffzellenaggregats von schräg oben betrachtet,
• 3 das Brennstoffzellenaggregat gemäß 2 von oben betrachtet,
• 4 das Brennstoffzellenaggregat gemäß 2 und 3 von der Seite betrachtet und
• 5 das Brennstoffzellenaggregat der 2 bis 4 von unten betrachtet,
• 6 ein Blockdiagramm einer Ausführungsform des Brennstoffzellenaggregats,
• 7 ein Blockdiagramm einer weiteren Ausführungsform des Brennstoffzellenaggregats,
• 8 eine Ausführungsform der Sammleranordnung in Explosionsdarstellung und
• 9 eine perspektivische Darstellung einer weiteren Sammleranordnung mit insgesamt drei Einlässen.

Further goals, features and advantageous refinements of the present development are explained in the following description of an exemplary embodiment. Show here:

• 1 a schematic side view of a motor vehicle,
• 2 a perspective view of an implementation of a fuel cell unit viewed obliquely from above,
• 3 the fuel cell unit according to 2 viewed from above,
• 4 the fuel cell unit according to 2 and 3 viewed from the side and
• 5 the fuel cell unit 2 until 4 viewed from below,
• 6 a block diagram of an embodiment of the fuel cell unit,
• 7 a block diagram of a further embodiment of the fuel cell unit,
• 8th an embodiment of the collector arrangement in an exploded view and
• 9 a perspective view of another collector arrangement with a total of three inlets.

Detailed description

This in 1 Motor vehicle 1 shown schematically has a body 2 with an interior functioning as a passenger cell 3. Furthermore, the motor vehicle 1 is provided with a drive 4, preferably an electric drive. The motor vehicle 1 also has one in the 2 until 7 schematically illustrated fuel cell unit 10. The fuel cell unit 10 points according to the block diagram of the 6 and 7 For example, on the cathode side there is a supply for a reaction gas, for example air carrying oxygen.

The fuel cell unit 10 also has a compressor 24, by means of which the supplied air or the supplied reaction gas can be compressed to an operating pressure. A cooler 26 is typically provided downstream of the compressor 24 to cool the fluid or gas heated as a result of the compression to a predetermined temperature level.

The fuel cell unit 10 also has a fuel cell stack 14, which is arranged sealingly in a fuel cell housing 12. An electrochemical process takes place in the fuel cell stack, typically converting molecular oxygen and molecular hydrogen into water and electrical energy.

On the inlet side, the fuel cell stack 14 is fluidly coupled to a supply line 44. The supply line 44 has a gas-carrying supply line 45, via which a gas or gas mixture can be supplied to the fuel cell stack 14. The fuel cell stack 14 is further coupled to an exhaust system 40 in a fluid-conducting manner. This has an exhaust pipe 41 which leads out of the fuel cell housing 12. A humidifier 20 is provided upstream of the fuel cell housing 12. The supply line 44 runs through the humidifier and the gas flowing in the supply line can be enriched with moisture in the area of the humidifier 20. The exhaust gas line 40 can also run through the humidifier 20, but can be fluidly coupled there to a moisture separator 22 in order to remove moisture from the gas or gas mixture carried in the exhaust gas line 40.

The humidifier 20 can have a large number of hollow fiber membranes, not shown in detail, which preferably extend in the housing of the humidifier 20 so that the exhaust gas flows through their inner cavities. The gaseous operating medium to be humidified and flowing towards the fuel cell stack can flow around such hollow fibers from the outside, particularly in the cross-flow direction. Reverse gas routing is also possible.

A controllable or controllable actuating element 70, for example in the form of a flap arrangement 71, is arranged in the supply line downstream of the humidifier 20 and upstream of the fuel cell stack 14. The actuating element 70 can in particular be controlled electronically. It acts as an inlet valve for the gaseous medium to be supplied to the fuel cell stack 14.

A first control element 50 is arranged in the exhaust system 40 downstream of the humidifier 20 or the separator 22. The first actuating element 50 can also have a flap arrangement 51.

The fuel cell housing 12 is also in flow connection with a flushing line 46. The flushing line 46 branches off from the supply line 44 upstream of the fuel cell stack 14 in the area of a branch 18 and opens with a flushing line 47 into the interior of the fuel cell housing 12, but outside the fuel cell stack 14. The flushing line 46 also has a flushing line 48, which from the fuel cell housing 12 opens into the exhaust line 40 or into the exhaust line 41.

Finally, the fuel cell unit 10 has a bypass line 42 with a bypass line 43. This branches off from the supply line 44 upstream of the fuel cell stack 14, preferably also upstream of the humidifier 20 in the area of a branch 16. The bypass line 42 with its bypass line 43 opens into the exhaust line 40 and thus into the exhaust line 41, there in an area which is located downstream of the fuel cell stack 14 and downstream of the separator 22.

A second adjusting element 56 is arranged in the bypass line 42 in order to adjust and/or change the flow cross section of the bypass line 43 as required. The bypass line 43 opens into the exhaust line 41.

Present and as in particular in the 2 until 5 and 8 and 9, the fuel cell unit 10 has a collector 30 with a collector body 34. The collector body 34 has a first inlet 31 and a second inlet 32. Furthermore, the collector body 34 has an outlet 35. The two inlets 31, 32 open into the outlet 35. The first inlet 31 is connected to the first control element 50. The second inlet 32 is connected to the second actuator 56.

The inlets 31, 32 each have a flange section 36, 37, as shown in particular in 9 is shown. The adjusting elements 50, 56 with their respective flap arrangements 51, 57 can be fastened to the flange sections 36, 37. In 8th associated fastening elements 72, for example in the form of screws or bolts, and seals 73 are also shown. These serve the sealing arrangement of the adjusting elements 50, 56 on the respective flange sections 36, 37.

Facing away from the flange section 36, the first actuating element 50 is also provided with a connecting piece 52. The connecting piece 52 can in particular be coupled or connected to a fluid or gas-carrying line piece 53 of the exhaust line 41. The line piece 53 can extend from the separator 22 to the collector. In terms of flow technology, this is followed in the flow direction by a line piece 54 of the collector body 34, which opens via the outlet 35 into another approximately L-shaped curved line piece 55 of the exhaust line 41.

In the exemplary embodiment 8th It is also shown that a separate connecting piece 49 is arranged downstream of the collector 30 on the exhaust pipe 41, which protrudes laterally from the wall of the exhaust pipe 41. That connecting piece 49 can be connected to a downstream end of the flushing line 48 in a fluid-carrying manner.

Similar or largely identical to what has already been described for the first inlet 31 and the first actuating element 50, the second inlet 32 can also be connected with its flange section 37 to the second actuating element 56. On the side of the actuating element 56 facing away from the flange 37, a connecting piece 58 can also be provided, which is fluidly coupled to the bypass line 43. The connecting pieces 52, 58 can be designed in particular to accommodate a fluid or gas-carrying hose.

The collector 30, in particular its collector body 34, can be designed essentially in one piece. The inlets 31, 32 can open into the outlet 35 in a Y-like manner. In the present exemplary embodiment, the first inlet 31 extends approximately in a straight line into the outlet 35. The second inlet 32 projects laterally into the side wall of the collector 30 at a predetermined angle. That rectilinear design of the first inlet 31 into the outlet 35 enables a significant reduction in the pressure loss emanating from the collector 30 for the exhaust system 40.

The collector 30 in particular provides a mounting base or a mounting support for the typically electrically controllable actuating elements 50, 56, by means of which the flow cross section through the respective lines, in particular through the exhaust line 40 and the bypass line 42, can be adjusted as required. If, for example, the flow-through cross section of the bypass line 42 and the supply line 44 is reduced to a minimum by means of the adjusting elements 70, 56, the interior of the fuel cell housing 12 can be effectively flushed with the medium flowing through the flushing line 46 in order to remove excess reaction gas and/or other reaction products , for example to remove moisture from the housing 12 via the flushing line 48.

In the further design of the collector 30 according to 7 and 9 the collector body 34 is provided with a third inlet 33. This has a connecting piece 38 for connecting the flushing line 48. In contrast to the design according to 8th The connecting piece 38 acts as the in 8th downstream connecting piece 49. In this respect, the separate implementation of the connecting piece 49 according to 8th in the embodiment according to 9 can be effectively dispensed with, which means that the installation space, weight and number of parts for the fuel cell unit can be reduced.

The embodiments shown merely show possible configurations of the development, for which numerous further variants are conceivable within the scope of development. The exemplary embodiments shown are in no way to be interpreted as limiting the scope, applicability or configuration options of the development. The present description merely shows the person skilled in the art one or a few possible implementation(s) of an exemplary embodiment. A wide variety of modifications can be made to the function and arrangement of the elements described without departing from the scope of protection defined by the following claims or its equivalents.

Reference symbol list

1

motor vehicle

2

Motor vehicle body

3

inner space

4

drive

10

Fuel cell aggregate

12

Fuel cell housing

14

Fuel cell stack

16

branch

18

branch

20

humidifier

22

separator

24

compressor

26

cooler

28

supply

30

Collector

31

inlet

32

inlet

33

inlet

34

collector body

35

outlet

36

flange section

37

flange section

38

Connection piece

40

Exhaust system

41

Exhaust pipe

42

Bypass line

43

Bypass line

44

supply line

45

supply line

46

Flushing strand

47

Flushing line

48

Flushing line

49

Connection piece

50

Control element

51

Flap arrangement

52

Connection piece

53

pipe section

54

pipe section

55

pipe section

56

Control element

57

Flap arrangement

58

Connection piece

60

pipe section

70

Control element

71

Flap arrangement

72

fastener

73

poetry

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102016118346 A1 [0002]

Claims (10)

Collector arrangement (30) for the exhaust system (40) of a fuel cell unit (10), which has a fuel cell stack (14) arranged in a fuel cell housing (12), with: - a collector body (34) which has a first inlet (31) and a second inlet (32) as well as an outlet (35), the first inlet (31) and the second inlet (32) flowing into the outlet (35). , - A first controllable control element (50, 56), which is arranged at one of the first inlet (31) and the second inlet (32) to regulate the cross section of the collector body (34) through which flow can flow. Collector arrangement (30). Claim 1 , further with a second controllable control element (50, 56), which is arranged at the other of the first inlet (31) and second inlet (32). Collector arrangement (30) according to one of the preceding claims, wherein the collector body (34) has a third inlet (33) which can be connected or is connected to a flushing line (48) of a flushing line (46) which is fluidly connected to the fuel cell housing (12). Flow connection is established. Collector arrangement (30) according to one of the preceding claims, wherein the first inlet (31) can be fluidly coupled or coupled to an exhaust gas line (41) of the fuel cell stack (14). Collector arrangement according to one of the preceding claims, wherein the second inlet (32) can be fluidly coupled or coupled to a bypass line (42) surrounding the fuel cell stack (14). Collector arrangement according to one of the preceding claims, wherein the first inlet (31) opens in a straight line into the outlet (35) and wherein the second inlet (32) flows into the first inlet (31) and/or into the outlet (35) at a predetermined angle. ends. Collector arrangement according to one of the preceding claims, wherein at least one of the first inlet (31) and second inlet (32) has a flange section (36, 37) facing away from the collector body (34), on which the first adjusting element (50) or the second adjusting element ( 56) can be arranged. Collector arrangement according to one of the preceding claims, wherein the first control element (50) or the second control element (56) has an electronically controllable flap arrangement (51, 57), throttle or valve arrangement. Fuel cell unit (10) with: - a fuel cell housing (12) in which a fuel cell stack (14) is arranged, - a gas-carrying supply line (44), which opens into the fuel cell stack (14), - a gas-carrying exhaust line (40), which leads out of the fuel cell stack (14), and with - a collector arrangement (30) according to one of the preceding claims, wherein the first inlet (31) of the collector arrangement (30) is fluidly connected to the fuel cell stack (14) and wherein the second inlet (32) is connected to a bypass line (43) of a bypass line ( 42), which branches off from the supply line (44) upstream of the fuel cell stack (14). Motor vehicle with a fuel cell unit (10). Claim 9 .

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