Activation device

Abstract

To provide an activation device for a plurality of electrolyte membranes / electrode structures for a fuel cell capable of appropriately imparting moisture to the plurality of electrolyte membranes / electrode structures and applying activation to them while preventing flooding from occurring.SOLUTION: The activation device includes a plurality of jigs (42). One electrolyte membrane / electrode structure (10) is sandwiched between two jigs. A first channel (64) and a second channel (72) are formed in one jig. In the first channel, a first activation gas supplied to an anode electrode (16) of the electrolyte membrane / electrode structure is circulated. A second activation gas supplied to the cathode electrode (14) of another electrolyte membrane / electrode structure is circulated in the second channel. One jig has a heat pipe (52). Heat is exchanged between the heat pipe and the first and second activation gases.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an activation device for activating an electrolyte membrane / electrode structure for a fuel cell.

Background Art

[0002] Conventionally, efforts aimed at mitigating or reducing the impact of climate change have continued, and research and development related to CO2 reduction have been conducted to achieve this. From this perspective, fuel cell vehicles (FCVs / Fuel Cell Vehicles) equipped with fuel cells have attracted attention. Fuel cell vehicles only emit water vapor and do not emit CO2, NO and SO x etc. This is because they do not emit such substances.

[0003] A fuel cell includes an electrolyte membrane / electrode structure (MEA). The MEA includes an electrolyte membrane made of a solid polymer having a first end face and a second end face, an anode electrode provided on the first end face of the electrolyte membrane, and a cathode electrode provided on the second end face of the electrolyte membrane. That is, the MEA is configured by sandwiching an electrolyte membrane between an anode electrode and a cathode electrode. When a set of MEAs is sandwiched between a pair of separators, a unit cell of the fuel cell is assembled. [[ID=​​​​​​​​​​​​​​​​​[Overview of the Initiative] [Problems that the invention aims to solve]

[0006] A first gas channel is formed in one of the separators in a pair. A second gas channel is formed in the other of the separators in a pair. During the process of activating the electrolyte membrane electrode structure (MEA), a moist gas may flow through the first and second gas channels. When the moist gas comes into contact with the anode electrode and the cathode electrode, respectively, moisture is imparted to the anode electrode and the cathode electrode.

[0007] When excessive moisture is applied to the anode or cathode electrode, a liquid film forms on the anode or cathode electrode. In other words, so-called flooding occurs. Under these conditions, the wet gas has difficulty penetrating each electrode catalyst of the anode or cathode electrode. In this case, the activation of the electrode catalyst is hindered.

[0008] Furthermore, when activation is performed at a high current density, the partial pressure of the activated gas decreases and the partial pressure of water vapor increases, particularly near the gas outlet of the second gas channel. Therefore, flooding is likely to occur near the gas outlet of the second gas channel. To avoid this, for example, the amount of moisture added to the humid gas can be reduced, thereby lowering the relative humidity of the humid gas. However, in this case, the activation efficiency of the MEA decreases.

[0009] The present invention aims to solve the problems described above. [Means for solving the problem]

[0010] According to one embodiment of the present invention, an activation device for activating an electrolyte membrane-electrode structure in which an electrolyte membrane is sandwiched between an anode electrode and a cathode electrode constituting a fuel cell, comprising: a plurality of jigs stacked with the electrolyte membrane-electrode structure sandwiched between them; a heat pipe provided on each of the plurality of jigs; a heat supply unit for supplying heat to the heat pipe; a control unit for controlling the heat supplied from the heat supply unit to the heat pipe; a first activation gas supply source for supplying a first activation gas; and a second activation gas supply source for supplying a second activation gas, wherein each of the plurality of jigs has a first surface facing the anode electrode, a second surface facing the cathode electrode, a first inlet extending along the stacking direction of the plurality of jigs and into which the first activation gas flows, and an extension along the first surface The provided activation device further includes a first channel communicating with the first inlet, a first outlet extending along the stacking direction and from which the first activated gas that has flowed through the first channel flows out, a second inlet extending along the stacking direction and from which the second activated gas flows in, a second channel extending along the second surface and communicating with the second inlet, and a second outlet extending along the stacking direction and from which the second activated gas that has flowed through the second channel flows out, wherein the first channel and the second channel extend in a direction parallel to or intersecting with respect to the heat pipe, and when the first surface or the second surface of each of the plurality of jigs is viewed, the first inlet, the first outlet, the second inlet and the second outlet are spaced apart from each other in the extending direction of the heat pipe and spaced apart from each other in a direction perpendicular to the extending direction.

[0011] As can be understood from the above, the first inlet, first outlet, second inlet, and second outlet are formed individually in the jig. That is, the formation locations of the first inlet, first outlet, second inlet, and second outlet do not coincide with each other. Furthermore, the first and second flow paths are independent gas flow paths and do not communicate with each other. [Effects of the Invention]

[0012] In this invention, a heat pipe is provided in the jig to adjust the temperatures of the first and second activated gases. The heat pipe has a high response speed to heat input or output. Therefore, by exchanging heat between the heat pipe and the first and second activated gases, the temperatures of the first and second activated gases can be quickly adjusted. In other words, the temperatures of the first and second activated gases are adjusted to a predetermined range.

[0013] This ensures that the liquid water content in the first and second channels of the jig is maintained within an appropriate range. Therefore, according to the present invention, it is possible to appropriately moisten and activate multiple electrolyte membrane and electrode structures while avoiding flooding in the first and second channels.

[0014] Furthermore, the first entrance, first exit, second entrance, and second exit are spaced apart from each other within the first and second surfaces of the jig. This allows for miniaturization of the jig. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a schematic system diagram of the activation device according to this embodiment. [Figure 2] Figure 2 is an enlarged cross-sectional view of the main part of the activation device. [Figure 3] Figure 3 is a schematic front view of the jig constituting the activation device, viewed from the side facing the anode electrode of the electrolyte membrane / electrode structure. [Figure 4] Figure 4 is a schematic front view of the jig constituting the activation device, viewed from the side facing the cathode electrode of the electrolyte membrane / electrode structure. [Figure 5] Figure 5 is a cross-sectional view of the VV line in Figure 4. [Figure 6] Figure 6 is a schematic front view of a jig in another embodiment, viewed from the side facing the anode electrode of the electrolyte membrane / electrode structure. [Figure 7]FIG. 7 is a schematic overall front view of a jig in another aspect as seen from the surface facing the cathode electrode of the electrolyte membrane - electrode structure.

Mode for Carrying Out the Invention

[0016] FIG. 1 is a schematic system diagram of an activation device 40 according to the present embodiment. The activation device 40 includes a plurality of jigs 42 that sandwich an electrolyte membrane - electrode structure 10. First, the electrolyte membrane - electrode structure 10 will be schematically described with reference to FIG. 2. In the following, the electrolyte membrane - electrode structure may also be referred to as "MEA".

[0017] The MEA 10 includes an electrolyte membrane 12 made of a solid polymer. Examples of the solid polymer include perfluorosulfonic acid. The electrolyte membrane 12 is sandwiched between a cathode electrode 14 and an anode electrode 16. The cathode electrode 14 has a first electrode catalyst layer 18 containing an electrode catalyst and a first gas diffusion layer 20 for supplying gas to the first electrode catalyst layer 18. The anode electrode 16 has a second electrode catalyst layer 22 containing an electrode catalyst and a second gas diffusion layer 24 for supplying gas to the second electrode catalyst layer 22. The MEA 10 is a thin film.

[0018] Next, the activation device 40 will be described with reference to FIGS. 1 to 6. As shown in FIGS. 1 and 2, the activation device 40 includes a plurality of jigs 42. The jig 42 has a substantially plate shape and is thin. By alternately laminating one jig 42 and one MEA 10, a laminate 44 in which the MEA 10 is sandwiched between two jigs 42 is formed. Therefore, in the laminate 44, two MEAs 10 abut against both end faces of one jig 42.

[0019] Hereinafter, for convenience, the MEA 10 located below the jig 42 in FIG. 2 is referred to as the first MEA 10a, and the MEA 10 located above the jig 42 in FIG. 2 is referred to as the second MEA 10b. The jig 42 has a first surface 46 facing the anode electrode 16 of the first MEA 10a and a second surface 48 facing the cathode electrode 14 of the second MEA 10b. In addition, like the first MEA 10a and the second MEA 10b, the other MEAs 10 are also arranged between the two jigs 42 such that the cathode electrode 14 faces downward in FIG. 2 and the anode electrode 16 faces upward in FIG. 2.

[0020] FIG. 3 is a schematic overall front view when the jig 42 is viewed from the first surface 46. FIG. 4 is a schematic overall front view when the jig 42 is viewed from the second surface 48. As shown in FIGS. 1 to 4, the jig 42 has two base plates 50a and 50b. A plurality of heat pipes 52 are sandwiched between the two base plates 50a and 50b. The heat pipes 52 extend in a direction orthogonal to the lamination direction of the laminate 44.

[0021] A heat supply part 54 made of a heater, a Peltier element, or the like is connected to the heat pipe 52. In this aspect, the heat supply part 54 is arranged at an end in the extending direction of the heat pipe 52. The heat supply part 54 applies heat to the heat pipe 52.

[0022] First inlets 56, first outlets 58, second inlets 60, and second outlets 62 are respectively formed at the four corners of the two base plates 50a and 50b. The first inlets 56, the first outlets 58, the second inlets 60, and the second outlets 62 are spaced apart from each other in the extending direction of the heat pipe 52. The first inlets 56, the first outlets 58, the second inlets 60, and the second outlets 62 are also spaced apart from each other in the direction orthogonal to the extending direction of the heat pipe 52. Typically, the first inlets 56 and the first outlets 58 are in a diagonal positional relationship with each other. Similarly, the second inlets 60 and the second outlets 62 are in a diagonal positional relationship with each other.

[0023] In the laminate 44, the first inlets 56 of multiple jigs 42 are connected to each other along the stacking direction. This forms a first inlet passage 56a through which multiple first inlets 56 are connected. Similarly, the first outlets 58 of multiple jigs 42 are also connected to each other along the stacking direction of the laminate 44. As a result, as shown in Figure 5, a first outlet passage 58a is formed through which multiple first outlets 58 are connected. Furthermore, the second inlets 60 and second outlets 62 are also connected to each other along the stacking direction of the laminate 44. As a result, a second inlet passage 60a is formed through which multiple second inlets 60 are connected, and a second outlet passage 62a is formed through which multiple second outlets 62 are connected.

[0024] The first inlet passage 56a and the first outlet passage 58a are flow passages for flowing the first activated gas along the stacking direction of the laminate 44. The first inlet passage 56a (first inlet 56) and the first outlet passage 58a (first outlet 58) are connected via the first flow path 64 shown in Figure 3. The second inlet passage 60a and the second outlet passage 62a are flow passages for flowing the second activated gas along the stacking direction of the laminate 44. The second inlet passage 60a (second inlet 60) and the second outlet passage 62a (second outlet 62) are connected via the second flow path 72 shown in Figure 4. The first inlet passage 56a is not connected to the second inlet passage 60a and the second outlet passage 62a. Similarly, the second inlet passage 60a is not connected to the first inlet passage 56a and the first outlet passage 58a.

[0025] As can be seen from Figure 2, the base plate 50a forms a first surface 46 facing the anode electrode 16 (second electrode catalyst layer 22) of the first MEA 10a. As shown in Figure 3, the first surface 46 has a first channel 64 that is recessed along the stacking direction and extends along the surface direction of the first surface 46. The first channel 64 has one first distribution channel 66, a plurality of first branch channels 68, and one first aggregation channel 70. The first distribution channel 66 is connected to the first inlet 56 (first inlet connecting passage 56a). The plurality of first branch channels 68 branch off from the first distribution channel 66. The plurality of first branch channels 68 converge at the first aggregation channel 70. The first aggregation channel 70 is connected to the first outlet 58 (first outlet connecting passage 58a). In this way, the first inlet 56 and the first outlet 58 are in communication via the first channel 64.

[0026] As can be seen from Figure 2, the base plate 50b forms a second surface 48 facing the cathode electrode 14 (first electrode catalyst layer 18) of the second MEA 10b. As shown in Figure 4, the second surface 48 has a second channel 72 that is recessed along the stacking direction and extends along the surface direction of the second surface 48. The second channel 72 has a plurality of second branch passages 74. The plurality of second branch passages 74 are each connected to, for example, a second inlet 60 (second inlet connecting passage 60a). Alternatively, as shown in the illustrated example, a second distribution passage 76 may be interposed between the second inlet 60 and two or more second branch passages 74. The plurality of second branch passages 74 are each connected to, for example, a second outlet 62 (second outlet connecting passage 62a). Alternatively, as shown in the illustrated example, a second collection passage 78 may be interposed between two or more second branch passages 74 and the second outlet 62.

[0027] As shown in Figures 3 and 4, in this embodiment, the first branch 68 and the second branch 74 are perpendicular to the heat pipe 52.

[0028] Multiple second branch lines 74 are provided with a first heat storage section 80 and a second heat storage section 82, respectively. In this case, the first heat storage section 80 and the second heat storage section 82 each consist of a recess that starts from the second branch line 74 and is recessed along the stacking direction of the laminate 44. That is, in this case, the first heat storage section 80 and the second heat storage section 82 are spaces that extend from the second branch line 74 toward the stacking direction of the laminate 44.

[0029] The volume of the second heat storage unit 82 is larger than the volume of the first heat storage unit 80. In other words, the heat storage units are arranged in order of increasing volume from the second inlet 60 to the second outlet 62. The second heat storage unit 82 captures a larger amount of the second humid gas than the first heat storage unit 80.

[0030] The number of heat storage units provided in one second branch circuit 74 is not particularly limited to the two shown in the illustrated example. Providing a heat storage unit in the second branch circuit 74 is not mandatory. A heat storage unit may also be provided in the first branch circuit 68.

[0031] The base plates 50a and 50b are provided with a first electrical terminal 84 and a second electrical terminal 86, respectively.

[0032] As shown in Figure 1, the activation device 40 includes a first gas line 90. A hydrogen gas supply unit 92 and a nitrogen gas supply unit 94 are connected to one end of the first gas line 90 via a first three-way valve 96. The hydrogen gas supply unit 92 is, for example, a hydrogen gas tank. The nitrogen gas supply unit 94 is, for example, a nitrogen gas tank. A first humidifier 98 is provided in the first gas line 90. The hydrogen gas supply unit 92 and the first humidifier 98 constitute a first humidifying gas supply unit, and the hydrogen gas to which moisture has been added in the first humidifier 98 is the first humidifying gas as the first activation gas.

[0033] The other end of the first gas line 90 is connected to the first inlet passage 56a via a pipe fitting. The first humid gas (humid hydrogen gas) that flows from the other end of the first gas line 90 into the first inlet passage 56a (inside the laminate 44) flows through the first channel 64 formed in the individual jigs 42.

[0034] The activation device 40 includes a second gas line 100. One end of the second gas line 100 is connected to the first outlet passage 58a via a pipe fitting. The other end of the second gas line 100 is connected to a first exhaust line 104 via a first exhaust valve 102. The excess first wet gas that has flowed through the first passage 64 is discharged from the first exhaust line 104 via the second gas line 100 and the first exhaust valve 102. Alternatively, a recovery device (not shown) may be provided in the first exhaust line 104 to recover the first wet gas.

[0035] The activation device 40 includes a third gas line 110. A nitrogen gas supply unit 112 and an oxidizer gas supply unit 114 are connected to one end of the third gas line 110 via a second three-way valve 116. The nitrogen gas supply unit 112 is, for example, a nitrogen gas tank as described above. The nitrogen gas is supplied as an inert second gas. In this embodiment, a nitrogen gas supply unit 94 connected to the first gas line 90 and a nitrogen gas supply unit 112 connected to the third gas line 110 are provided separately. However, a single nitrogen gas supply unit may be connected to both the first gas line 90 and the third gas line 110.

[0036] The oxidizer gas supply unit 114 is, for example, a compressor that compresses the atmosphere. Alternatively, the oxidizer gas supply unit 114 may be an oxygen gas cylinder. A second humidifier 118 is provided in the third gas line 110. The oxidizer gas supply unit 114 and the second humidifier 118 constitute the second humidifying gas supply unit. The oxidizer gas to which moisture has been added in the second humidifier 118 is the second humidifying gas, which acts as the second activating gas.

[0037] The other end of the third gas line 110 is connected to the second inlet passage 60a via a pipe fitting. The second wet gas (wet oxidizing gas) that flows from the other end of the third gas line 110 into the second inlet passage 60a (inside the laminate 44) flows through the second channel 72 formed in the individual jigs 42.

[0038] The activation device 40 includes a fourth gas line 120. One end of the fourth gas line 120 is connected to the second outlet passage 62a via a pipe fitting. The other end of the fourth gas line 120 is connected to a second exhaust line 124 via a second exhaust valve 122. The excess second humid gas that has flowed through the second passage 72 is discharged from the second exhaust line 124 via the fourth gas line 120 and the second exhaust valve 122. Alternatively, a recovery device (not shown) may be provided in the second exhaust line 124 to recover the second humid gas.

[0039] The activation device 40 includes an electrical parameter detection unit 130 and a control unit 134. The electrical parameter detection unit 130 includes, for example, a voltage measuring instrument 136. One voltage measuring instrument 136 is electrically connected to the first electrical terminal 84 of one jig 42 and the second electrical terminal 86 of another jig 42, thereby measuring the voltage of one MEA 10. Hereinafter, this voltage will be conveniently referred to as the "cell voltage". The electrical parameter detection unit 130 may also be a resistance measuring instrument, a current measuring instrument, or an impedance measuring instrument. The electrical parameter detection unit 130 may have all of these measuring instruments.

[0040] The activation device 40 further includes a pressure parameter detection unit 140. The pressure parameter detection unit 140 includes an anode differential pressure gauge 142 and a cathode differential pressure gauge 144.

[0041] The anode differential pressure gauge 142 detects the differential pressure between the gas pressure in the first gas line 90 and the gas pressure in the second gas line 100. This differential pressure is equal to the differential pressure between the inlet to the anode electrode 16 in the first flow path 64 and the outlet from the anode electrode 16 in the first flow path 64. The cathode differential pressure gauge 144 detects the differential pressure between the gas pressure in the third gas line 110 and the gas pressure in the fourth gas line 120. This differential pressure is equal to the differential pressure between the inlet to the cathode electrode 14 in the second branch path 74 and the outlet from the cathode electrode 14 in the second branch path 74.

[0042] The control unit 134 is electrically connected to the heat supply unit 54, the voltage measuring instrument 136, the anode differential pressure gauge 142, and the cathode differential pressure gauge 144. Information regarding the cell voltage measured by the voltage measuring instrument 136 is transmitted to the control unit 134 as an information signal. The control unit 134 also receives information signals regarding the gas differential pressure measured by the anode differential pressure gauge 142 and the cathode differential pressure gauge 144, respectively.

[0043] As will be described later, in this embodiment, power generation aging is performed. For this purpose, an external load 154 is electrically connected to the laminate 44 via the first external connection terminal 150 and the second external connection terminal 152.

[0044] The activation device 40 according to this embodiment is basically configured as described above. Next, the effects of the activation device 40 according to this embodiment will be explained.

[0045] To activate the MEA10, the operator first alternately stacks the MEA10 and the jig 42 before they are assembled into unit cells. This forms a laminate 44. The laminate 44 has a first inlet passage 56a, a first outlet passage 58a, a second inlet passage 60a, and a second outlet passage 62a. The first inlet passage 56a, the first outlet passage 58a, the second inlet passage 60a, and the second outlet passage 62a extend along the stacking direction.

[0046] The worker connects the first gas line 90 to the first inlet passage 56a and the second gas line 100 to the first outlet passage 58a. Similarly, the worker connects the third gas line 110 to the second inlet passage 60a and the fourth gas line 120 to the second outlet passage 62a.

[0047] In this state, the operator issues a command signal to the control unit 134 to "start activation". Based on this command signal, the control unit 134 first replaces the air in the first flow path 64 and the second branch path 74 with moist nitrogen gas.

[0048] Upon receiving a command signal, the control unit 134 operates the first three-way valve 96 in a direction that connects the nitrogen gas supply unit 94 to the first gas line 90. Furthermore, the control unit 134 operates the second three-way valve 116 in a direction that connects the nitrogen gas supply unit 112 to the third gas line 110. The control unit 134 also opens the first exhaust valve 102 and the second exhaust valve 122.

[0049] Nitrogen gas supplied from the nitrogen gas supply unit 94 passes through the first humidifier 98 to become moist nitrogen gas, and then flows through the first gas line 90. The moist nitrogen gas flows into the first flow path 64 via the first inlet connecting passage 56a (first inlet 56) of the jig 42. The moist nitrogen gas moves from the first inlet 56 to the first distribution channel 66, and then from the first distribution channel 66 to the first branch channel 68. While flowing through the first branch channel 68, a portion of the moist nitrogen gas reaches the second electrode catalyst layer 22 via the second gas diffusion layer 24 of the anode electrode 16 of the first MEA 10a. As a result, moisture is added to the anode electrode 16 and the electrolyte membrane 12.

[0050] The excess moist nitrogen gas that has flowed through the first branch 68 merges at the first confluence 70. The merged moist nitrogen gas then moves from the first confluence 70 to the first outlet 58 (first outlet connecting passage 58a). The moist nitrogen gas then flows into the second gas line 100, passes through the first exhaust valve 102, and is discharged from the first exhaust line 104.

[0051] Nitrogen gas supplied from the nitrogen gas supply unit 112 passes through the second humidifier 118 to become moist nitrogen gas, and then flows through the third gas line 110. The moist nitrogen gas flows into the second flow path 72 (second branch path 74) via the second inlet connecting passage 60a (second inlet 60) of the jig 42. While flowing through the second branch path 74, a portion of the moist nitrogen gas reaches the first electrode catalyst layer 18 via the first gas diffusion layer 20 of the cathode electrode 14 of the second MEA 10b. As a result, moisture is added to the cathode electrode 14 and the electrolyte membrane 12.

[0052] The excess moist nitrogen gas that has flowed through the second branch passage 74 merges, for example, at the second outlet 62 (second outlet connecting passage 62a). The merged moist nitrogen gas flows into the fourth gas line 120, then passes through the second exhaust valve 122 and is discharged from the second exhaust line 124.

[0053] As a result, air is discharged from the first channel 64 and the second channel 72 and replaced with moist nitrogen gas. After a predetermined time has elapsed, the control unit 134 operates the first three-way valve 96 in a direction that connects the hydrogen gas supply unit 92 to the first gas line 90.

[0054] The hydrogen gas supplied from the hydrogen gas supply unit 92 passes through the first humidifier 98 to become humidified hydrogen gas (first humidified gas), and then flows into the first flow path 64 via the first inlet communication passage 56a (first inlet 56) of the jig 42. While the first humidified gas flows through the first flow path 64, a portion of the first humidified gas reaches the second electrode catalyst layer 22 via the second gas diffusion layer 24 of the anode electrode 16 of the first MEA 10a. Thus, the application of moisture to the anode electrode 16 and the electrolyte membrane 12 continues. The excess first humidified gas that has flowed through the first flow path 64 moves from the first outlet communication passage 58a to the second gas line 100, and then passes through the first exhaust valve 102 and is discharged from the first exhaust line 104. This first humidified gas may be recovered by a recovery mechanism (not shown).

[0055] Furthermore, the control unit 134 switches the second three-way valve 116 to shut off communication between the nitrogen gas supply unit 112 and the third gas line 110, and to connect the oxidizer gas supply unit 114 and the third gas line 110. As a result, an oxidizer gas containing oxygen gas (typically compressed air) is supplied. The oxidizer gas passes through the second humidifier 118 to become a humidified oxidizer gas (second humidified gas), and then flows into the second flow path 72 (second branch path 74) via the second inlet communication passage 60a of the jig 42.

[0056] A portion of the second humidified gas reaches the first electrode catalyst layer 18 via the first gas diffusion layer 20 of the cathode electrode 14 of the second MEA 10b while flowing through the second branch passage 74. Thus, the application of moisture to the cathode electrode 14 and the electrolyte membrane 12 continues. The excess second humidified gas that has flowed through the second branch passage 74 flows into the fourth gas line 120 via the second outlet communication passage 62a. Subsequently, the second humidified gas passes through the second exhaust valve 122 and is discharged from the second exhaust line 124.

[0057] As the second humid gas flows through the second branch 74, a portion of the second humid gas enters the first heat storage unit 80 and the second heat storage unit 82 individually. Since the temperature of the second humid gas is several tens of degrees Celsius to over a hundred degrees Celsius, the first heat storage unit 80 and the second heat storage unit 82 each store heat as it enters. As described above, the heat storage capacity of the second heat storage unit 82 is larger than that of the first heat storage unit 80. The second humid gas that enters the first heat storage unit 80 and the second heat storage unit 82 temporarily remains inside these heat storage units.

[0058] In this case, hydrogen is ionized in the second electrode catalyst layer 22 of the anode electrode 16 to produce protons and electrons. The protons conduct through the electrolyte membrane 12 and reach the first electrode catalyst layer 18 of the cathode electrode 14. The electrons reach the first electrode catalyst layer 18 of the cathode electrode 14 via the external load 154. In the first electrode catalyst layer 18, oxygen, protons, and electrons chemically combine to produce water.

[0059] The electrochemical reaction described above is an exothermic reaction; that is, MEA10 becomes heated. When this heat is transferred to the first and second humidified gases, their temperatures rise. At this time, the heat pipe 52 absorbs heat from the first and second humidified gases. In this way, the heat pipe 52 normally cools the first and second humidified gases, respectively.

[0060] The control unit 134 constantly receives information signals regarding the cell voltage of the MEA10. Based on the cell voltage, the control unit 134 determines the concentration overvoltage. When the control unit 134 recognizes that the concentration overvoltage has reached a predetermined upper limit based on the increase in humidity inside the MEA10, it determines that "the humidification state of the MEA10 is at an appropriate upper limit."

[0061] The control unit 134 is further input with the differential pressure measured by the anode differential pressure gauge 142 and the differential pressure measured by the cathode differential pressure gauge 144. As described above, the differential pressure measured by the anode differential pressure gauge 142 is equal to the differential pressure between the inlet to the anode electrode 16 in the first flow path 64 and the outlet from the anode electrode 16 in the first flow path 64. The differential pressure measured by the cathode differential pressure gauge 144 is equal to the differential pressure between the inlet to the cathode electrode 14 in the second branch path 74 and the outlet from the cathode electrode 14 in the second branch path 74. If either differential pressure reaches a predetermined upper limit, the control unit 134 will determine that "the humidification state of the MEA 10 is at the appropriate upper limit."

[0062] Having made the above determination, the control unit 134 increases the temperature of the heat pipe 52. Specifically, the control unit 134 increases the amount of heat transferred from the heat supply unit 54 to the heat pipe 52 by increasing the amount of heat generated by the heat supply unit 54.

[0063] This control increases the amount of heat supplied from the heat pipe 52 to the first and second humidified gases. Consequently, the effective dew point temperatures of the first and second humidified gases increase. As a result, condensation becomes less likely to occur in the first and second humidified gases. This causes a gradual decrease in the amount of liquid water in the first and second flow paths 64 and 72, respectively. As the amount of liquid water decreases, the concentration overpotential, which is determined based on the cell voltage, also decreases.

[0064] Here, the effective dew point temperature of the first humid gas is the local dew point temperature of the first humid gas at each point in the first flow path 64. Similarly, the effective dew point temperature of the second humid gas is the local dew point temperature of the second humid gas at each point in the second flow path 72. The effective dew point temperature of the first humid gas and the second humid gas, respectively, is determined by the amount of heat supplied from the heat pipe 52 to the first humid gas and the second humid gas, respectively.

[0065] If the liquid water volume in the first channel 64 and the second branch channel 74 decreases excessively, there is a concern that the electrolyte membrane 12 may dry out. Therefore, when the concentration overvoltage reaches a predetermined lower limit, the control unit 134 determines that "the humidification state of the MEA 10 is at the appropriate lower limit." The control unit 134 also makes the same determination when the differential pressure between the first gas line 90 and the second gas line 100 reaches a predetermined lower limit.

[0066] Having made the above determination, the control unit 134 lowers the temperature of the heat pipe 52. Specifically, the control unit 134 reduces the amount of heat transferred from the heat supply unit 54 to the heat pipe 52 by reducing the amount of heat generated by the heat supply unit 54.

[0067] This control reduces the amount of heat supplied from the heat pipe 52 to the first and second humidified gases. Consequently, the effective dew point temperatures of the first and second humidified gases decrease. As a result, condensation becomes more likely in the first and second humidified gases. This causes the amount of liquid water in the first and second flow paths 64 and 72 to gradually increase. As the amount of liquid water increases, the concentration overvoltage, which is determined based on the cell voltage, increases. In addition, the differential pressure between the first gas line 90 and the second gas line 100 increases.

[0068] The heat pipe 52 has a high response speed to the application or cessation of heat application. Therefore, when heat is applied to the heat pipe 52 from the heat supply unit 54, the temperature of the first humid gas in the first channel 64 and the temperature of the second humid gas in the second channel 72 rise rapidly. Conversely, when the application of heat from the heat supply unit 54 to the heat pipe 52 is stopped, the temperature of the first humid gas in the first channel 64 and the temperature of the second humid gas in the second channel 72 fall rapidly.

[0069] As described above, the temperatures of the first and second humidified gases are rapidly adjusted. That is, the temperatures of the first and second humidified gases can be kept approximately constant. Therefore, the amount of liquid water in each of the first and second channels 64 and 72 can be kept at an appropriate level, thus preventing flooding. Thus, according to this embodiment, when activating multiple MEAs 10s simultaneously, flooding in the first and second channels 64 and 72 of the jig 42 can be prevented.

[0070] As a result, a sufficient amount of the first humidifying gas reaches the second electrode catalyst layer 22 of the anode electrode 16, and a sufficient amount of the second humidifying gas reaches the first electrode catalyst layer 18 of the cathode electrode 14. This allows the MEA 10 to be fully activated.

[0071] In addition, a first heat storage section 80 and a second heat storage section 82 are formed in the middle of the second branch passage 74. Heat is stored in the first heat storage section 80 and the second heat storage section 82 as the second humid gas enters. Therefore, heat is transferred from the first heat storage section 80 and the second heat storage section 82 to the second humid gas flowing through the second branch passage 74. Since the heat storage capacity of the second heat storage section 82 is larger than that of the first heat storage section 80, a large amount of heat is transferred to the second humid gas as it approaches the second outlet 62.

[0072] Therefore, in this embodiment, a large amount of heat is supplied to the second humid gas as it approaches the second outlet 62. Consequently, even if the amount of heat supplied from the heat pipe 52 decreases rapidly in the second flow path 72, a decrease in the effective dew point temperature is avoided, especially near the second outlet 62. Consequently, flooding in the second flow path 72 is suppressed. In other words, flooding can be easily prevented even when multiple MEAs 10 are activated simultaneously.

[0073] Furthermore, in this embodiment, the heat storage capacity of the heat storage section is increased as it approaches the second outlet 62. As a result, the dew point temperature in the second flow path 72 increases from the second inlet 60 towards the second outlet 62. That is, in the second flow path 72, a positive gradient is formed in the effective dew point temperature as the second humid gas flows from upstream to downstream. Therefore, even when the effective dew point temperature of the second humid gas decreases in the second flow path 72, the formation of condensed water (liquid water) is suppressed throughout the entire second flow path 72.

[0074] Furthermore, in this embodiment, the effective dew point temperature is highest near the second outlet 62 in the second flow path 72. Therefore, condensation is less likely to form at the second outlet 62. As a result, the second outlet 62 is not blocked by condensation. Consequently, any condensation that forms along the second flow path 72 can be quickly discharged from the second outlet 62.

[0075] After the activation of MEA10 is completed as described above, the control unit 134 controls the first three-way valve 96 to block communication between the hydrogen gas supply unit 92 and the first gas line 90, and to connect the nitrogen gas supply unit 94 and the first gas line 90. The control unit 134 also controls the second three-way valve 116 to block communication between the third gas line 110 and the oxidizer gas supply unit 114, and to connect the third gas line 110 and the nitrogen gas supply unit 112.

[0076] In this state, nitrogen gas is supplied from the nitrogen gas supply unit 94 to the first flow path 64, and nitrogen gas is supplied from the nitrogen gas supply unit 112 to the second flow path 72. The nitrogen gas becomes moist nitrogen gas and is supplied to the anode electrode 16 and the cathode electrode 14. The moist nitrogen gas is discharged from the first exhaust valve 102 and the second exhaust valve 122, respectively, via the second gas line 100 and the fourth gas line 120. As a result, the first flow path 64 and the second flow path 72 are replaced with moist nitrogen gas.

[0077] In this embodiment, an example is shown in which the heat pipe 52 extends in a direction perpendicular to the first branch 68 and the second branch 74. However, the direction in which the heat pipe 52 extends is not particularly limited. For example, as shown in Figures 6 and 7, the heat pipe 52 may extend parallel to the first branch 68 and the second branch 74. In Figures 6 and 7, the same reference numerals are used for components that are the same as those shown in Figures 1 to 5.

[0078] In this embodiment, the heat supply unit 54 can be positioned, for example, between the first inlet 56 and the second outlet 62. In this case, at least a part (preferably all) of the heat supply unit 54 fits inside the jig 42. This makes it possible to miniaturize the activation device 40.

[0079] As described above, this embodiment is an activation device (40) for activating an electrolyte membrane / electrode structure (10) in which an electrolyte membrane (12) is sandwiched between an anode electrode (16) and a cathode electrode (14) constituting a fuel cell, comprising: a plurality of jigs (42) stacked with the electrolyte membrane / electrode structure sandwiched between them; a heat pipe (52) provided on each of the plurality of jigs; a heat supply unit (54) that applies heat to the heat pipe; a control unit (134) that controls the heat applied from the heat supply unit to the heat pipe; a first activation gas supply source that supplies a first activation gas; and a second activation gas supply source that supplies a second activation gas, wherein each of the plurality of jigs has a first surface (46) facing the anode electrode, a second surface (48) facing the cathode electrode, and a first inlet extending along the stacking direction of the plurality of jigs and into which the first activation gas flows. The present invention discloses an activation device having (56), a first flow path (64) extending along the first surface and communicating with the first inlet, a first outlet (58) extending along the stacking direction and through which the first activated gas that has flowed through the first flow path flows out, a second inlet (60) extending along the stacking direction and through which the second activated gas flows in, a second flow path (72) extending along the second surface and communicating with the second inlet, and a second outlet (62) extending along the stacking direction and through which the second activated gas that has flowed through the second flow path flows out, wherein the first flow path and the second flow path extend in a direction parallel to or perpendicular to the heat pipe, and when the first surface or the second surface of each of the plurality of jigs is viewed, the first inlet, the first outlet, the second inlet and the second outlet are spaced apart from each other in the direction in which the heat pipe extends and spaced apart from each other in a direction perpendicular to the direction in which the heat pipe extends.

[0080] Heat pipes have a high response speed to heat input or output. Therefore, by exchanging heat between the heat pipe and the first and second activated gases, the temperatures of the first and second activated gases can be rapidly adjusted. In other words, the temperatures of the first and second activated gases can be adjusted to a predetermined range.

[0081] This adjusts the effective dew point temperatures of the first and second activating gases to an appropriate temperature range. As a result, the liquid water content in the first and second channels of the jig is maintained within an appropriate range. Therefore, it is possible to appropriately moisten multiple electrolyte membrane and electrode structures while avoiding flooding in the first and second channels. In this way, multiple electrolyte membrane and electrode structures can be activated simultaneously.

[0082] This embodiment discloses an activation device in which the first flow path has a plurality of first branch paths (68), the plurality of first branch paths branch off from the first inlet or first distribution path (66) and converge at the first gathering path (70) or the first outlet, and the second flow path has a plurality of second branch paths (74), the plurality of second branch paths branch off from the second inlet or second distribution path (76) and converge at the second gathering path (78) or the second outlet.

[0083] The first and second branching channels allow the first and second activating gases to reach a wide area of ​​the electrolyte membrane and electrode structure. In other words, the electrolyte membrane and electrode structure can be activated over a wide area. Furthermore, by combining the first branching channels, the first inlet into which the first activating gas flows in is consolidated into a single location. The first outlet out of which the first activating gas flows out is also consolidated into a single location. The same applies to the second branching channel. Therefore, the size of the jig can be reduced.

[0084] Furthermore, when multiple jigs are stacked, by aligning the positions of the first entrance, first exit, second entrance, and second exit, the first entrance passage, first exit passage, second entrance passage, and second exit passage extending in the stacking direction of the jigs can be easily formed.

[0085] This embodiment discloses an activation device having a heat storage section (80, 82) provided in at least one of the first or second flow path.

[0086] Heat pipes have a high response speed to heat supply and / or cessation of heat supply. Therefore, when the temperature of the activated gas flowing through the gas channel of an activation device is controlled by a heat pipe, it is presumed that the local temperature (effective dew point temperature) of the activated gas will be approximately uniform. In this case, when the amount of heat supplied to the activated gas from the heat pipe decreases rapidly, the effective dew point temperature of the activated gas in the gas channel may decrease simultaneously, potentially causing condensation throughout the entire gas channel. This phenomenon is expected to cause flooding, despite the high response speed of the heat pipe to heat inflow and outflow. In particular, fuel cell stacks installed in large vehicles such as trucks have larger MEAs. When activating such MEAs, the flow path length of the gas channel in the activation device becomes relatively long. When condensation occurs in a gas channel with a long flow path length, there is a concern that flooding is more likely to occur due to the large amount of condensation produced.

[0087] In contrast, in a configuration with a heat storage unit, heat from the heat storage unit is transferred to the activated gas flowing through the gas channel. This heat transfer increases the effective dew point temperature of the activated gas. As a result, the condensation of water vapor in the gas channel is further suppressed. Therefore, flooding is more easily prevented.

[0088] This embodiment discloses an activation device in which the heat storage section is one or more recesses that are recessed starting from the first or second flow path and spaced apart from the first or second flow path.

[0089] In this case, the activated gas enters the recess. Since the activated gas is tens of degrees Celsius to over a hundred degrees Celsius, the heat storage section stores heat. Thus, with this configuration, it is easy to construct the heat storage section.

[0090] This embodiment discloses an activation device in which the heat storage section is two or more recesses that are recessed starting from the first or second flow path and spaced apart from the first or second flow path, the heat storage capacities of the two or more recesses differ from each other, and the two or more recesses are arranged in the first flow path from the first inlet to the first outlet in order from the recess with the smallest heat storage capacity to the recess with the largest heat storage capacity, or in the second flow path from the second inlet to the second outlet in order from the recess with the smallest heat storage capacity to the recess with the largest heat storage capacity.

[0091] In this case, the effective dew point temperature increases as you move from the upstream to the downstream of the first or second flow path (gas flow path). That is, a positive temperature gradient is formed in the effective dew point temperature. As a result, condensation is less likely to occur from the activated gas as you move from the inlet to the outlet of the gas flow path. For this reason, simultaneous condensation throughout the entire gas flow path is avoided. Moreover, since the effective dew point temperature can be increased near the outlet of the gas flow path, condensation is suppressed at the outlet of the gas flow path. Consequently, blockage of the outlet of the gas flow path by condensation is avoided. Therefore, even if condensation occurs from the activated gas in the middle of the gas flow path, the condensation can be quickly discharged from the outlet.

[0092] In particular, during power generation aging, water is generated at the cathode electrode as activation progresses. Therefore, flooding is likely to occur near the second outlet of the second channel facing the cathode electrode. However, in the above configuration, it is possible to supply a large amount of heat from the heat storage unit located near the first or second outlet to the activated gas that has flowed through the first or second channel and reached the vicinity of the first or second outlet. Therefore, it is possible to avoid a decrease in the effective dew point temperature of the activated gas near the outlet. As a result, the occurrence of flooding is further suppressed.

[0093] This embodiment discloses an activation device in which the first flow path and the second flow path intersect the heat pipe, and the heat supply unit is located at the end of the heat pipe in the direction of extension.

[0094] This embodiment discloses an activation device in which the first flow path and the second flow path and the heat pipe extend in parallel, and the heat supply unit is positioned between two of the first inlet, first outlet, second inlet, and second outlet.

[0095] In either case, it is possible to reduce the amount of protrusion of the heat supply unit from the jig. Therefore, the jig and the activation device can be miniaturized.

[0096] Typically, the first inlet and the first outlet are formed at positions diagonally opposite to each other. Similarly, the second inlet and the second outlet are formed at positions diagonally opposite to each other. That is, this embodiment discloses an activation device in which the first inlet and the first outlet are at diagonal positions, and the second inlet and the second outlet are at diagonal positions.

[0097] In this case, it is easy to evenly contact the entire anode electrode with the first activating gas. Similarly, it is easy to evenly contact the entire cathode electrode with the second activating gas. Therefore, the MEA can be activated almost uniformly throughout.

[0098] Furthermore, the present invention is not limited to the disclosure described above, and can take various configurations without departing from the spirit of the invention. [Explanation of Symbols]

[0099] 10, 10a, 10b...Electrolyte membrane / electrode structure 12...Electrolyte membrane 14... Cathode electrode 16... Anode electrode 40...Activation device 42...Jig 44...Laminated structure 46...First surface 48...Second side 52...Heat pipe 54...Heat supply section 56...First inlet 56a...1st inlet communication path 58...1st outlet 58a...1st outlet communication path 60...2nd inlet 60a...Second entrance connecting passage 62...Second exit 62a...Second exit connecting passage 64...First channel 66...First distribution route 68...First branching route 70...First confluence route 72...Second route 74...Second junction 76...Second distribution point 78...Second gathering path 80...First heat storage section 82...Second heat storage unit 90...First gas line 92...Hydrogen gas supply unit 98...First humidifier 100...2nd gas line 110...3rd gas line 114... Oxidizing gas supply unit 118... Second humidifier 120...4th gas line 130...Electrical parameter detection unit 134...Control unit 136...Voltage measuring instrument 140... Pressure parameter detection unit 142... Anode differential pressure gauge 144... Cathode differential pressure gauge 154... External load

Claims

1. In an activation device for activating an electrolyte membrane / electrode structure in which an electrolyte membrane is sandwiched between the anode electrode and cathode electrode constituting a fuel cell, Multiple jigs are stacked with the electrolyte membrane / electrode structure sandwiched between them, A heat pipe is provided on each of the aforementioned multiple jigs, A heat supply unit that applies heat to the heat pipe, A control unit that controls the heat supplied from the heat supply unit to the heat pipe, A first activated gas supply source that supplies the first activated gas, A second activated gas supply source that supplies the second activated gas, Equipped with, Each of the aforementioned multiple jigs has a first surface facing the anode electrode, The second surface facing the cathode electrode, A first inlet extending along the stacking direction of the plurality of jigs and into which the first activated gas flows, A first channel extending along the first surface and communicating with the first inlet, A first outlet extending along the stacking direction and through which the first activated gas that has flowed through the first channel flows out, A second inlet extending along the stacking direction and into which the second activated gas flows, A second flow path extending along the second surface and communicating with the second inlet, A second outlet extending along the stacking direction and through which the second activated gas that has flowed through the second channel flows out, It has, The first and second flow paths extend in directions parallel to or intersecting the heat pipe. When the first or second surface of each of the plurality of jigs is viewed, the first inlet, the first outlet, the second inlet, and the second outlet are spaced apart from each other in the direction in which the heat pipe extends, and are also spaced apart from each other in a direction perpendicular to the direction in which the heat pipe extends. The activation device further comprises a heat storage unit provided in at least one of the first or second flow channels. The heat storage section is one or more recesses that are recessed starting from the first flow path or the second flow path and spaced apart from the first flow path or the second flow path, in an activation device.

2. An activation device for activating an electrolyte membrane / electrode structure in which an electrolyte membrane is sandwiched between an anode electrode and a cathode electrode constituting a fuel cell, Multiple jigs are stacked with the electrolyte membrane / electrode structure sandwiched between them, A heat pipe is provided on each of the aforementioned multiple jigs, A heat supply unit that applies heat to the heat pipe, A control unit that controls the heat supplied from the heat supply unit to the heat pipe, A first activated gas supply source that supplies the first activated gas, A second activated gas supply source that supplies the second activated gas, Equipped with, Each of the aforementioned multiple jigs has a first surface facing the anode electrode, The second surface facing the cathode electrode, A first inlet extending along the stacking direction of the plurality of jigs and into which the first activated gas flows, A first channel extending along the first surface and communicating with the first inlet, A first outlet extending along the stacking direction and through which the first activated gas that has flowed through the first channel flows out, A second inlet extending along the stacking direction and into which the second activated gas flows, A second flow path extending along the second surface and communicating with the second inlet, A second outlet extending along the stacking direction and through which the second activated gas that has flowed through the second channel flows out, It has, The first and second flow paths extend in directions parallel to or intersecting the heat pipe. When the first or second surface of each of the plurality of jigs is viewed, the first inlet, the first outlet, the second inlet, and the second outlet are spaced apart from each other in the direction in which the heat pipe extends, and are also spaced apart from each other in a direction perpendicular to the direction in which the heat pipe extends. The activation device further comprises a heat storage unit provided in at least one of the first or second flow channels. The heat storage section is a set of two or more recesses that are recessed starting from the first or second flow path and spaced apart from the first or second flow path. The heat storage capacities of the two or more recesses differ from each other. An activation device in which the two or more recesses are arranged in the first flow path from the first inlet to the first outlet in order from recesses with small heat storage capacity to recesses with large heat storage capacity, or in the second flow path from the second inlet to the second outlet in order from recesses with small heat storage capacity to recesses with large heat storage capacity.

3. An activation device for activating an electrolyte membrane / electrode structure in which an electrolyte membrane is sandwiched between an anode electrode and a cathode electrode constituting a fuel cell, Multiple jigs are stacked with the electrolyte membrane / electrode structure sandwiched between them, A heat pipe is provided on each of the aforementioned multiple jigs, A heat supply unit that applies heat to the heat pipe, A control unit that controls the heat supplied from the heat supply unit to the heat pipe, A first activated gas supply source that supplies the first activated gas, A second activated gas supply source that supplies the second activated gas, Equipped with, Each of the aforementioned multiple jigs has a first surface facing the anode electrode, The second surface facing the cathode electrode, A first inlet extending along the stacking direction of the plurality of jigs and into which the first activated gas flows, A first channel extending along the first surface and communicating with the first inlet, A first outlet extending along the stacking direction and through which the first activated gas that has flowed through the first channel flows out, A second inlet extending along the stacking direction and into which the second activated gas flows, A second flow path extending along the second surface and communicating with the second inlet, A second outlet extending along the stacking direction and through which the second activated gas that has flowed through the second channel flows out, It has, The first and second flow paths extend in directions parallel to or intersecting the heat pipe. When the first or second surface of each of the plurality of jigs is viewed, the first inlet, the first outlet, the second inlet, and the second outlet are spaced apart from each other in the direction in which the heat pipe extends, and are also spaced apart from each other in a direction perpendicular to the direction in which the heat pipe extends. An activation device in which the first flow path and the second flow path and the heat pipe extend in parallel, and the heat supply unit is positioned between two of the first inlet, first outlet, second inlet, and second outlet.

4. An activation device according to any one of claims 1 to 3, wherein the first flow path has a plurality of first branch paths, the plurality of first branch paths branch off from the first inlet or first distribution path and converge at the first gathering path or the first outlet, and the second flow path has a plurality of second branch paths, the plurality of second branch paths branch off from the second inlet or second distribution path and converge at the second gathering path or the second outlet.

5. An activation device according to any one of claims 1 to 3, wherein the first flow path and the second flow path extend so as to intersect with the heat pipe, and the heat supply unit is located at the end of the heat pipe in the direction of extension.

6. An activation device according to any one of claims 1 to 3, wherein the first inlet and the first outlet are in a diagonal positional relationship, and the second inlet and the second outlet are in a diagonal positional relationship.

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