Filter unit having particulate filter and ion exchanger, and cooling circuit having filter unit

Abstract

A filter unit (30) for a coolant, the filter unit (30) comprising a housing (45), a particulate filter (32) arranged in the housing (45), an ion exchanger (33) arranged in the housing (45), an inlet (35), a first outlet (39), and a main flow conduit (63) extending between the inlet (35) and the first outlet (39), the particulate filter (32) being arranged in the main flow conduit (63). The filter unit (30) further comprises a side flow conduit (54) branching off from the main flow conduit (63) and configured to direct a portion of the coolant from the main flow conduit (63) to the ion exchanger (33), and a second outlet (43) downstream of the ion exchanger (33) and fluidly connected to the inlet (35).

Description

Technical Field

[0001] This invention relates to a filter unit for a coolant, the filter unit comprising a particulate filter and an ion exchanger. Furthermore, this invention relates to a cooling circuit comprising a filter unit and a fuel cell. Background Technology

[0002] US 10,804,546 B2 discloses a filter unit having a particulate filter and an ion exchanger arranged in a housing. It also discloses a cooling circuit in which a pump, at least one heat exchanger, and the filter unit are integrated to cool the fuel cell. The ion exchanger ensures that the conductivity of the coolant flowing through the fuel cell is not too high to avoid electrical short-circuit effects or power losses in the fuel cell.

[0003] In the filter unit of US 10,804,546 B2, the particulate filter and ion exchanger are configured as a single component housed within a mains channel inside the housing. The mains channel extends from the inlet to the outlet of the filter unit. Therefore, the mains flow through the filter unit must pass through both the particulate filter and the ion exchanger, meaning that operation of this filter unit can involve relatively high pressure losses. Because they are combined into one component, the ion exchanger and particulate filter can only be replaced together. Emergency operation of the filter unit is not possible; in such an emergency, the ion exchanger can be replaced, but the particulate filter remains effective to protect the fuel cell from particulate matter. Summary of the Invention

[0004] The present invention is based on the purpose of providing a filter unit having an ion exchanger and a particulate filter, the filter unit being highly efficient and operable in a simple and safe manner.

[0005] The objective of this invention is achieved using a combination of features according to claim 1. Embodiments of this invention can be obtained from the dependent claims of claim 1.

[0006] According to the invention, a sideflow conduit branches off from the main flow conduit, for example, upstream of the particulate filter or at least upstream of the filter section of the particulate filter. The sideflow conduit is configured to guide a portion of the coolant from the main flow conduit to the ion exchanger. A second outlet is located downstream of the ion exchanger and is fluidly connected to the inlet.

[0007] The filter unit according to the invention ensures that only sideflow passes through the ion exchanger. In one embodiment, greater than 70% or even greater than 80% of the main flow through the filter unit passes through a particulate filter arranged in the main flow channel, without having to pass through the ion exchanger. By splitting the flow into main and side flows, pressure losses occurring in the filter unit during operation can be kept at a low level. The separate arrangement of the particulate filter and the ion exchanger in the housing results in a simple and compact design for the filter unit.

[0008] In addition to the filter section that performs the actual particle filtration, the particle filter may have a fastening section by which the particle filter is secured and / or aligned in the main flow channel. For example, the fastening section may have a preferred circumferential contact surface resting against the inner wall of the main flow channel.

[0009] The contact surface can be a substantially cylindrical shell surface with at least one opening through which coolant can enter the side flow pipe from the main flow pipe. In this embodiment, the cylindrical shell surface with at least one opening is located upstream of the filter section of the filter unit. The main flow can be directed through the fastening section, thereby directing the side flow through the opening in the shell surface into the side flow pipe, and the main flow passes through the filter section of the particulate filter.

[0010] The filter unit may also include a coolant tank disposed within the housing, which is fluidly connected to the outlet of the ion exchanger. Therefore, a sideflow passes through the ion exchanger and then enters the coolant tank. The coolant can settle or degas in the coolant tank. The coolant tank can also function as a compensation tank to compensate for pressure fluctuations in the filter unit and / or maintain a certain amount of coolant. The coolant can exit the coolant tank through a second outlet.

[0011] In one embodiment, the filter unit may further include a pressure control valve disposed at the coolant tank and an exhaust line connected to the pressure control valve. The pressure in the coolant tank may be limited by the pressure control valve. Air used to vent the coolant tank or remove excess coolant may be discharged via the exhaust line.

[0012] The ion exchanger can be a replaceable cartridge. The filter unit may also include a first valve upstream of the ion exchanger and a second valve downstream of the ion exchanger. When the valves are closed, the cartridge is fluidly separated from the other components of the filter unit, allowing the cartridge to be replaced even if the filter unit continues to operate and the main flow is directed through the particulate filter. When the valves are closed, the main flow corresponds to the total flow through the filter unit.

[0013] In one embodiment, the particulate filter is arranged in a replaceable manner in the main flow channel. For this purpose, the filter unit may have an inlet connector detachably connected to the housing. In the connected state, the inlet connector axially secures the particulate filter in the main flow channel. In the disconnected state, the particulate filter can be removed from the main flow channel. Preferably, the connection between the inlet connector and the housing is a threaded connection.

[0014] The filter unit may also include a conductivity sensor upstream of the ion exchanger. Alternatively, the conductivity sensor may be located downstream of the ion exchanger, as seen in the flow direction. The conductivity sensor can be used to determine the conductivity of the coolant. For example, the measurement results from the conductivity sensor can be used to determine whether the ion exchanger in the filter unit must be replaced with a new one. The conductivity sensor can also be used for control, by which the ratio of the side flow to the main flow is adjusted. For example, if the coolant conductivity is too high, the flow rate through the ion exchanger can be increased via one or more of the aforementioned valves. Therefore, the valves can also be designed as control valves.

[0015] The main flow channel between the inlet and outlet of the filter unit preferably extends in a straight line. The main flow channel between the inlet and outlet can have a substantially constant or varying cross-section in terms of size and shape. In one embodiment, the main flow channel has a basic shape of a hollow cylinder. This straight main flow channel can reduce flow losses. Furthermore, by using such a straight main flow channel, it is easy to accommodate the particulate filter within the main flow channel and to enable possible replacement of the particulate filter.

[0016] In one embodiment, when the filter unit is in the upright position (operating position), the flow through the ion exchanger is from bottom to top. However, this is only one embodiment, and in other embodiments, the flow through the ion exchanger may be from top to bottom or from side to side. The longitudinal axis of the ion exchanger thus continues vertically. The upper end of the ion exchanger may engage with a cover, by which the ion exchanger is secured within the housing. The cover may be attached to the housing using suitable fastening devices (e.g., threaded connections or bayonet connections). In one embodiment, once the cover is separated from the housing, the ion exchanger can be pulled out of the housing along its longitudinal axis and replaced with a new ion exchanger.

[0017] The sideflow duct can be defined by a first integrally formed, one-piece housing half and a separate cover plate. The first housing half can be an injection-molded part made of plastic. The separate cover plate allows for relatively flexible design of the sideflow duct and other components / areas of the filter unit (such as the aforementioned coolant tank), while also enabling simple manufacturing of the first housing half.

[0018] Another object of the present invention is to provide a cooling circuit for a fuel cell, which is achieved by a combination of the features of claim 13. Embodiments can be obtained from the dependent claims of claim 13.

[0019] The cooling circuit according to the invention includes a pump and the aforementioned filter unit, wherein the inlet of the filter unit is connected to the pump outlet of the pump. A first outlet of the filter unit is connected to the coolant inlet of the fuel cell. A second outlet of the filter unit is directly connected to the pump inlet, such that coolant passing through the ion exchanger is supplied to the pump inlet.

[0020] During operation of the cooling circuit, the pump delivers coolant through the inlet to the filter unit. The total flow into the filter unit is divided into a main flow and a side flow. The main flow passes through the particulate filter and exits the filter unit through a first outlet. The coolant filtered through the particulate filter then flows into the fuel cell from the first outlet. After flowing through the fuel cell, the coolant is cooled, preferably by at least one heat exchanger or cooler, and flows toward the pump inlet. Before the pump inlet, the coolant discharged from the fuel cell mixes with the coolant that has already passed through the ion exchanger and exited the filter unit through a second outlet.

[0021] The vent line from the coolant tank can be connected to the connection line between the coolant outlet and the pump inlet of the fuel cell. This connection ensures that unfiltered coolant carrying particles does not enter the fuel cell, because the particulate filter of the filter unit is forced to be positioned upstream of the coolant inlet of the fuel cell. Attached Figure Description

[0022] The invention will be explained in more detail with reference to the embodiments shown in the accompanying drawings. Wherein: Figure 1 The cooling circuit of the fuel cell to be cooled is shown; Figure 2 A first embodiment of the filter unit according to the present invention is shown in a side view; Figure 3 It shows Figure 2 Front view of the filter unit; Figure 4 It shows along Figure 3 The cross section of the centerline AA; Figure 5 It shows Figure 2 Rear view of the filter unit; Figure 6 It shows along Figure 5 The cross-section of the centerline BB; Figure 7 A second embodiment of the filter unit according to the invention is shown in a side view with a partial cross-section; Figure 8 It shows Figure 7 Bottom view of the filter unit; and Figure 9 It shows along Figure 8 Cross section of the centerline CC. Detailed Implementation

[0023] Figure 1 A cooling circuit 1 for the fuel cell 10 is shown. The cooling circuit 1 includes a pump 20 and a filter unit 30. Figure 1 In the illustration, the various components of the filter unit 30 are surrounded by a dotted-dash system line 31. Liquid coolant is circulated through the cooling circuit 1 via pump 20.

[0024] The filter unit 30 includes a particulate filter 32, an ion exchanger 33, and a coolant tank 34. Coolant flows from the pump outlet 21 of the pump 20 to the inlet 35 of the filter unit 30. Within the filter unit 30, the main flow 36 is divided into a main flow 37 and secondary or side flows 38. The main flow 37 passes through the particulate filter 32 to reach the first outlet 39 of the filter unit 30. The coolant filtered by the particulate filter 32 flows from the first outlet 39 to the coolant inlet 11 of the fuel cell 10. The fuel cell 10 is cooled by the coolant, which exits the fuel cell 10 at the coolant outlet 12 and is guided back to the pump 20 via the connecting line 80. Coolant enters the pump 20 at the pump inlet 22.

[0025] Side flow 38 is directed through ion exchanger 33, with a first valve 40 positioned upstream of ion exchanger 33 and a second valve 41 positioned downstream of ion exchanger 33. A conductivity sensor 42 is positioned upstream of ion exchanger 33, by means of which the conductivity of the coolant can be measured. After flowing through ion exchanger 33, the coolant reaches coolant tank 34. Coolant can flow from coolant tank 34 to pressure control valve 44 connected to connecting line 80 and / or a second outlet 43 connected to connecting line 81. Coolant from coolant tank 34 reaches pump inlet 22 of pump 20 via connecting line 81. Pressure control valve 44 is provided for venting coolant tank 34 and / or for regulating pressure in coolant tank 34; air and excess coolant can be released from coolant tank 34 into connecting line 80 through pressure control valve 44.

[0026] Coolant from the coolant outlet 12 of the fuel cell 10 is directed via connecting line 80 to distribution valve 82, which divides the incoming coolant flow into different portions. The first portion is directed directly to pump 20. The second portion is directed back to pump via the first heat exchanger or cooler 73. The third portion releases heat to the second heat exchanger or cooler 74 and is then routed only to pump 20. The range of each portion of the flow can be adjusted via distribution valve 82. If the second heat exchanger is part of the interior heating system of the vehicle in which the fuel cell 10 is installed, the interior temperature of the vehicle can be increased by increasing the portion of the flow through heat exchanger 74.

[0027] An additional heat exchanger 85 is provided parallel to the main flow 36 or parallel to the filter unit 30. This additional heat exchanger 85 may be designed as an intercooler, for example. However, the coolant absorbs heat here compared to the other heat exchangers 83, 84. The coolant flowing through the heat exchanger 85 reaches the distribution valve 82 via connecting line 86 (see dashed line) and via connecting line 80.

[0028] Figures 2 to 6 Various views of a first embodiment of the filter unit 30 according to the present invention are shown. Figure 1 Components that are similar to or the same as those shown are given the same reference numerals. Figure 4 It is along Figure 3 The cross-sectional view along line AA shows the longitudinal section of the ion exchanger 33. The ion exchanger 33 is designed here as a replaceable cylindrical tube. The ion exchanger 33 is housed in a housing 45, which includes a first or lower housing half 46 and a second or upper housing half 47.

[0029] Housing 45 defines a first housing section in which the ion exchanger 33 is disposed. A circular socket 48 for the filter unit 30 is integrally molded onto the first housing half 46. To replace the filter unit 30, a screw cap 49 is unscrewed from the second housing half 47, allowing the filter unit 30 to be pulled vertically upward along the longitudinal axis 50 out of the first housing section. A new cartridge can then be inserted through the upward-opening second housing half 47 until it contacts the socket 48. By screwing the screw cap 49 onto the ion exchanger 33, it is secured at the upper end 51 and thus aligned within the housing 45.

[0030] A connecting device can be provided between the cover 49 and the cylinder 33, by which the cylinder 33 and the cover 49 can be locked together in the direction of the longitudinal axis, so that the cylinder can be pulled out of the housing 45 with the help of the cover 49. With the help of the special design of the connecting device, a key lock system can be provided between the cover 49 and the cylinder 33, thereby avoiding unsuitable cylinders or making the use of unsuitable cylinders more difficult.

[0031] A conductivity sensor 42 is disposed near a socket 48, which is attached to the first housing half 46 by screws 53. The conductivity sensor 42 is used to determine the conductivity of the coolant before it enters the ion exchanger 33. The coolant reaches the ion exchanger 33 via a side-flow conduit 54 (see also...). Figure 6 The flow of coolant through ion exchanger 33 is indicated by arrow 55. Therefore, coolant flows upwards through ion exchanger 33. Coolant exits ion exchanger 33 through opening 56 at the upper end 51. The upper end may also be referred to as the outlet of the ion exchanger. The coolant then flows downwards along the side of the upper end of ion exchanger 33 (see arrow 57), and then through... Figure 4 An opening not visible in the cross-sectional view leads into the coolant tank 34. The coolant tank 34 is defined by the second housing section of the housing 45. A partition wall 58 separates the first housing section from the second housing section.

[0032] An upper opening for the coolant tank 34 is provided in the second half of the second housing half 47. A valve unit 59 with a pressure control valve is disposed on this opening, through which the pressure in the coolant tank 34 can be controlled. The valve unit 59 has a connector 60 for a drain line through which air or excess coolant can escape from the coolant tank 34. In addition, the valve unit 59 has an unscrewed filler cap 61 capable of filling the coolant tank 34.

[0033] Especially from Figure 6 It can be seen that, Figure 6 It shows along Figure 5 The cross-section of line BB in the filter unit 30 includes a separate inlet connector 62 at the inlet 35, which is attached to the first housing half 46. A straight main flow channel 63 with a circular cross-section is provided between the inlet 35 and the first outlet 39, from which a side flow channel 54 branches off. The branching occurs upstream of the particulate filter 32, which is placed within the main flow channel 63. Therefore, the main flow is directed only through the main flow channel 63, and thus only through the particulate filter 32 and not through the ion exchanger 33. Consequently, most of the coolant passing through the filter unit is directed through the main flow channel, which has relatively small flow losses due to its shape and size design. Figure 6 It also shows how the main flow 36 is divided into the main flow 37 and the side flow 38.

[0034] The support leg 52 is integrally formed with the first housing half 46 of the housing. The support leg 52 ensures a stable operating position in which the longitudinal axis 50 of the ion exchanger extends in the vertical direction.

[0035] Figures 7 to 9 Another embodiment of the filter unit 30 according to the present invention is shown. Figures 7 to 9 The accompanying drawings specifically reference the figures... Figures 2 to 6 The differences from the first embodiment. Therefore, regarding common features, refer to the accompanying drawings of the example of the first embodiment.

[0036] from Figure 7 As can be seen from the cutaway region 64, the inlet connector 62 of the second embodiment is detachably connected to the first housing half 46. For this purpose, the first housing half 46 has an external thread 65 that engages with the internal thread 66 of the inlet connector 62.

[0037] The particulate filter 64 of the second embodiment has a hollow cylindrical fastening section 67 and a conical filter section 68. The fastening section 67 ensures the fastening and alignment of the particulate filter 32 in the main flow channel 63. Actual filtration of the coolant occurs in the filter section 68. In the case of the particulate filter 64 of the first embodiment, a distinction can also be made between the fastening section 67 and the filter section 68, whereby the fastening section 67 has only a short axial length.

[0038] The fastening section 67 of the particulate filter 32 in the second embodiment has a plurality of openings 69 on its circumferential surface, allowing some of the coolant flowing through the inlet connector 62 into the main flow pipe 63 to enter the side flow pipe (see [link]). Figure 9 ). Figure 9 Arrow 70 illustrates the flow of coolant from inlet connector 62 through side flow pipe 54, ion exchanger 33, to coolant tank 34. Arrow 70 also illustrates the flow of coolant through ion exchanger 33 into coolant tank 34.

[0039] As in Figure 9 As can be seen, in addition to the first housing half 46, the side flow duct 54 is also defined by a separate cover plate 71. Figure 8 The cover plate 71, shown in the top view, is attached to the first housing half 46. Although the separate cover plate 71 increases the assembly work of the filter unit, it helps to produce the first housing half 46 as a one-piece injection molded part.

[0040] The seal between the inlet connector 62 and the first housing half 46 is provided by a seal 72, which is a combination of radial and axial seals and has an approximately crescent shape. This shape has a slightly curved outer surface and an inner surface with a small retaining profile. The retaining profile is seated in a circumferential groove in the fastening section 67 of the particulate filter 32. In the assembled state, the seal 72 is in sealing contact with the first housing half 46, the inlet connector 62, and the fastening section 67 of the particulate filter 32.

[0041] To replace particulate filter 32, unscrew inlet connector 62. Then, in Figure 7 As shown in the diagram, the particulate filter 32 can be pulled to the right out of the main flow channel 63. After inserting a new particulate filter, screw the inlet connector back onto the first housing half 46 to secure the particulate filter 32 in the main flow channel 63.

[0042] List of reference numerals 1 Cooling circuit 10 Fuel Cells 11 Coolant Inlet 12 Coolant outlet 20 pumps 21 Pump outlet 22 Pump inlet 30 filter units 31 System Piping 32 Particulate Filter 33 Ion exchangers 34 Coolant Tank 35 Entrances 36 Total Flow 37 Mainstream 38 Side Flow 39 First Exit 40 First Valve 41 Second valve 42 Conductivity Sensor 43 Second Exit 44 Pressure control valve 45. Housing 46 First shell half 47 Second shell half 48 sockets 49 Caps / Screw Caps 50 Longitudinal axis 51 Top End / Outlet 52 legs 53 Screws 54 Side Flow Pipe 55 Arrow / Coolant Flow Direction 56 Opening 57 Arrow / Direction of coolant flow 58. Partition wall 59 Valve Unit 60 connector 61 Filler Cap 62 Inlet Connector 63 Mainstream Pipelines 64. Sectional area 65 external thread 66 Internal Thread 67 Fastening Section 68 Filter Section 69 Opening 70 Arrow / Coolant Flow Direction 71 Cover plate 72 Seals 80 Connecting pipes 81 Connecting Pipelines 82 Distribution Valve 83 Heat exchangers / coolers 84 Heat Exchanger / Cooler 85 Heat Exchanger / Cooler

Claims

1. A filter unit (30) for a coolant, the filter unit (30) comprising: Casing (45); A particulate filter (32) is arranged in a housing (45); An ion exchanger (33) is arranged in a housing (45); Entrance (35); First Exit (39); A main pipe (63) extends between the inlet (35) and the first outlet (39), and a particulate filter (32) is arranged in the main pipe (63); A side-flow duct (54) branches off from the main flow duct (63) and is configured to direct a portion of the coolant from the main flow duct (63) to the ion exchanger (33); and The second outlet (43) is downstream of the ion exchanger (33) and fluidly connected to the inlet (35).

2. The filter unit (30) according to claim 1, wherein, The particulate filter (32) includes a fastening section (67) for abutting against the inner wall of the main pipe (63).

3. The filter unit (30) according to claim 2, wherein, The fastening section (67) includes a substantially cylindrical lateral surface having at least one opening (69) through which coolant enters the lateral flow pipe (54).

4. The filter unit (30) according to any one of claims 1 to 3 further includes a coolant tank (34) arranged in the housing (45) and fluidly connected to the outlet (51) of the ion exchanger (33).

5. The filter unit (30) according to claim 4 further comprises: Pressure control valve (44), said pressure control valve (44) is located at coolant tank (34); and An exhaust line is connected to a pressure control valve (44).

6. The filter unit (30) according to any one of claims 1 to 5, wherein, The ion exchanger (33) is a replaceable cylinder.

7. The filter unit (30) according to any one of claims 1 to 6 further comprises: The first valve (40) is located upstream of the ion exchanger (33); and The second valve (41) is located downstream of the ion exchanger (33).

8. The filter unit (30) according to any one of claims 1 to 7, wherein, The particulate filter (32) can be alternatively arranged in the main pipeline (63).

9. The filter unit (30) according to any one of claims 1 to 8 further includes a conductivity sensor (42) upstream or downstream of the ion exchanger (33).

10. The filter unit (30) according to any one of claims 1 to 4, wherein, The ion exchanger (33) is configured to flow through from bottom to top in one operating position of the filter unit (30).

11. The filter unit (30) according to any one of claims 1 to 10, wherein, The main channel (63) between the inlet (35) and the first outlet (39) is straight.

12. The filter unit (30) according to any one of claims 1 to 11, wherein, The side flow duct (63) is confined by the first housing half (46) of the housing (45) and a separate cover plate (71).

13. The filter unit (30) according to any one of claims 1 to 12, wherein, The side flow pipe (54) branches off from the main flow pipe (63) upstream of the particulate filter (32) or at least upstream of the filter section (68) of the particulate filter (32).

14. A cooling circuit (1), comprising: Fuel cell (10); Pump (20); and The filter unit (30) according to any one of claims 1 to 13. The inlet (35) of the filter unit (30) is connected to the pump outlet (21) of the pump (20). The first outlet (39) of the filter unit (30) is connected to the coolant inlet (11) of the fuel cell (10), and The second outlet (43) is directly connected to the pump inlet (22) of the pump (20).

15. The cooling circuit (1) according to claim 13, wherein, The cooling circuit (1) includes the filter unit (30) according to claim 5, and The exhaust line is connected to the connecting line (80) between the coolant outlet (12) and the pump inlet (22) of the fuel cell (10).

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