Ion exchanger for fuel cell and fuel cell system

Abstract

To provide an ion exchanger for a fuel cell and a fuel cell system which can contribute to reduction in a total amount of an anion exchange resin stored in the ion exchanger.SOLUTION: An ion exchanger 30 includes an anion exchange resin which is provided on a cooling circuit 20 for circulating cooling water for cooling a fuel cell 10, and removes anions contained in the cooling water by ion exchange. The ion exchanger includes a first storage part 31 mainly storing a first anion exchange resin, and a second storage part 32 which is arranged in parallel with the first storage part, has higher heat resistance than that of the first anion exchange resin, has a small ion exchange capacity and mainly stores a second anion exchange resin. The ion exchanger includes a first supply passage 33 and a second supply passage 34 for supplying cooling water to each of the first storage part and the second storage part, and a switching valve 35. The switching valve switches an inflow form of the cooling water to the first supply passage and the second supply passage.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an ion exchanger for a fuel cell and a fuel cell system. [Background technology]

[0002] The fuel cell system described in Patent Document 1 includes a fuel cell, a circulation path connected to the fuel cell and circulating cooling water for cooling a power generation section of the fuel cell, a radiator provided in the circulation path, and a bypass path connected to the circulation path so as to bypass the radiator. An ion exchanger is provided midway along the bypass path. The ion exchanger contains ion exchange resin that removes ions contained in the cooling water by ion exchange. The ion exchange resin includes a cation exchange resin that ion-exchanges cations contained in the cooling water, and an anion exchange resin that ion-exchanges anions contained in the cooling water.

[0003] In fuel cells, strongly acidic cation exchange resins and strongly basic anion exchange resins are used. Strongly basic anion exchange resins include OH-type anion exchange resins. The heat resistance temperature of OH-type strongly basic anion exchange resins is about 60 degrees.

[0004] Furthermore, in fuel cells, there is a tendency to increase the temperature of the power generation section during power generation in order to improve power generation efficiency, and as the temperature of the power generation section increases, the temperature of the cooling water also increases. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-095931 A Summary of the Invention [Problem to be solved by the invention]

[0006] In a fuel cell provided with an ion exchanger having the aforementioned OH-type strongly basic anion exchange resin, the anion exchange resin is thermally deteriorated when the temperature of the cooling water exceeds the heat resistance temperature of the OH-type anion exchange resin. For this reason, it is conceivable to increase the amount of the anion exchange resin to be accommodated, taking into consideration that the amount of anion exchange resin capable of ion exchange decreases due to thermal deterioration. However, in this case, the higher the temperature of the power generation unit is in order to improve the power generation efficiency, the more the amount of the anion exchange resin must be increased.

[0007] In response to this, it is possible to use a carbonate-type anion exchange resin as the strongly basic anion exchange resin, but in this case, the carbonate-type anion exchange resin has a smaller ion exchange capacity than the OH-type anion exchange resin, so that the capacity of the anion exchange resin increases. [Means for solving the problem]

[0008] The ion exchanger for a fuel cell to solve the above problems is provided in a cooling circuit through which cooling water for cooling a fuel cell flows, and is equipped with an anion exchange resin that removes anions contained in the cooling water by ion exchange, and is equipped with a first storage section that mainly contains a first anion exchange resin, a second storage section that is arranged in parallel with the first storage section and mainly contains a second anion exchange resin that has higher heat resistance and smaller ion exchange capacity than the first anion exchange resin, a first supply passage and a second supply passage that supply the cooling water to the first storage section and the second storage section, respectively, and a switching valve that switches the inflow mode of the cooling water to the first supply passage and the second supply passage.

[0009] According to this configuration, for example, when the temperature of the cooling water is lower than the heat resistance temperature of the first anion exchange resin, the switching valve allows the cooling water to flow into the first supply passage. This allows the anions contained in the cooling water to be efficiently removed by ion exchange using the first anion exchange resin that is mainly accommodated in the first accommodation section. In addition, since cooling water that is lower than the heat resistance temperature is supplied to the first anion exchange resin in the first accommodation section, thermal deterioration of the first anion exchange resin can be effectively suppressed.

[0010] Furthermore, for example, when the temperature of the cooling water is higher than the heat resistance temperature of the first anion exchange resin, the switching valve can cause the cooling water to flow into the second supply passage, whereby the second anion exchange resin mainly accommodated in the second accommodation portion can suppress thermal deterioration of the second anion exchange resin and remove anions contained in the cooling water by ion exchange.

[0011] In this way, when the temperature of the cooling water is low, it is possible to perform ion exchange using the first storage section that mainly contains the first anion exchange resin, which has a larger ion exchange capacity but a lower heat resistance than the second anion exchange resin. Also, when the temperature of the cooling water is high, it is possible to perform ion exchange using the second storage section that mainly contains the second anion exchange resin, which has a smaller ion exchange capacity but a higher heat resistance than the first anion exchange resin. Therefore, it is possible to contribute to reducing the total amount of anion exchange resins stored in the ion exchanger.

[0012] In addition, a fuel cell system for solving the above problem includes a fuel cell stack, a cooling circuit that supplies cooling water to the fuel cell stack, the ion exchanger provided in the cooling circuit, a temperature detection unit that detects the temperature of the cooling water, and a control unit that controls the switching valve, wherein when the temperature of the cooling water is lower than a predetermined temperature set based on the heat resistance temperature of the first anion exchange resin, the control unit controls the switching valve so that the cooling water flows into the first supply passage, and when the temperature of the cooling water is equal to or higher than the predetermined temperature, the control unit controls the switching valve so that the cooling water flows into the second supply passage.

[0013] According to this configuration, when the temperature of the cooling water is lower than a predetermined temperature set based on the heat resistance temperature of the first anion exchange resin, the control unit controls the switching valve to allow the cooling water to flow into the first supply passage. This allows the anions contained in the cooling water to be efficiently removed by ion exchange using the first anion exchange resin mainly accommodated in the first accommodation unit. In addition, since cooling water having a temperature lower than the predetermined temperature is supplied to the first anion exchange resin in the first accommodation unit, thermal deterioration of the first anion exchange resin can be effectively suppressed.

[0014] When the temperature of the cooling water is equal to or higher than the predetermined temperature, the control unit controls the switching valve to allow the cooling water to flow into the second supply passage, thereby making it possible to remove anions contained in the cooling water by ion exchange while suppressing thermal deterioration of the second anion exchange resin by the second anion exchange resin mainly accommodated in the second accommodation unit.

[0015] In this way, when the temperature of the cooling water is low, ion exchange is performed using the first storage section, which mainly contains the first anion exchange resin, which has a lower heat resistance but a larger ion exchange capacity than the second anion exchange resin. On the other hand, when the temperature of the cooling water is high, ion exchange is performed using the second storage section, which mainly contains the second anion exchange resin, which has a lower ion exchange capacity but a higher heat resistance than the first anion exchange resin. This can therefore contribute to reducing the total amount of anion exchange resins stored in the ion exchanger.

[0016] In addition, a fuel cell system for solving the above problem includes a fuel cell stack, a cooling circuit that supplies cooling water to the fuel cell stack, and the ion exchanger provided in the cooling circuit, wherein the switching valve is a temperature-sensitive valve that deforms according to the temperature of the cooling water, and when the temperature of the cooling water is lower than a predetermined temperature that is set based on the heat resistance temperature of the first anion exchange resin, the switching valve deforms so that the cooling water flows into the first supply passage, and when the temperature of the cooling water is equal to or higher than the predetermined temperature, the switching valve deforms so that the cooling water flows into the second supply passage.

[0017] According to this configuration, when the temperature of the cooling water is lower than a predetermined temperature set based on the heat resistance temperature of the first anion exchange resin, the switching valve deforms according to the temperature of the cooling water, and the cooling water flows into the first supply passage. This allows the anions contained in the cooling water to be efficiently removed by ion exchange using the first anion exchange resin mainly accommodated in the first accommodation section. In addition, since cooling water having a temperature lower than the predetermined temperature is supplied to the first anion exchange resin in the first accommodation section, thermal deterioration of the first anion exchange resin can be effectively suppressed.

[0018] Furthermore, when the temperature of the cooling water is equal to or higher than the predetermined temperature, the switching valve deforms in response to the temperature of the cooling water, causing the cooling water to flow into the second supply passage. This makes it possible to remove anions contained in the cooling water by ion exchange while suppressing thermal deterioration of the second anion exchange resin by the second anion exchange resin mainly accommodated in the second accommodation portion.

[0019] In this way, when the temperature of the cooling water is low, ion exchange is performed using the first storage section, which mainly contains the first anion exchange resin, which has a lower heat resistance but a larger ion exchange capacity than the second anion exchange resin. On the other hand, when the temperature of the cooling water is high, ion exchange is performed using the second storage section, which mainly contains the second anion exchange resin, which has a lower ion exchange capacity but a higher heat resistance than the first anion exchange resin. This can therefore contribute to reducing the total amount of anion exchange resins stored in the ion exchanger. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic diagram showing the schematic configuration of a cooling circuit of a fuel cell system. [Diagram 2] FIG. 2 is a schematic diagram showing a modified example of the ion exchanger. [Diagram 3] FIG. 3 is a schematic diagram showing the ion exchanger in a state where the switching valve in FIG. 2 is switched. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of an ion exchanger for a fuel cell and a fuel cell system will be described with reference to FIG. As shown in FIG. 1, the fuel cell system includes a fuel cell 10, a cooling circuit 20, and a control unit .

[0022] <Fuel cell 10> The fuel cell 10 is a solid polymer fuel cell, and includes a fuel cell stack 11 configured by stacking a plurality of unit cells (none of which are shown) each having a power generation section.

[0023] <Cooling circuit 20> The fuel cell 10 is provided in the middle of the cooling circuit 20. The cooling circuit 20 has an internal flow path 11c provided inside the fuel cell stack 11, a supply path 11a provided in the fuel cell 10 for supplying cooling water to the internal flow path 11c, and a discharge path 11b provided in the fuel cell 10 for discharging the cooling water from the internal flow path 11c.

[0024] The cooling circuit 20 has a main passage 21 that connects the supply passage 11a and the discharge passage 11b. The main passage 21 is provided with a pump 14 and a radiator 12. The cooling water discharged from the pump 14 is supplied to the fuel cell 10. The flow direction of the cooling water in the main passage 21 shown in Fig. 1 is counterclockwise.

[0025] The radiator 12 is provided downstream of the fuel cell 10 and upstream of the pump 14. The radiator 12 includes a heat exchanger 12a that cools the coolant by exchanging heat between the coolant and the refrigerant circulating through a refrigerant piping (not shown), and an electric fan 12b that cools the refrigerant by air cooling.

[0026] The cooling circuit 20 is provided with a bypass passage 22 that bypasses the radiator 12. The downstream end of the bypass passage 22 is connected to the main passage 21 on the upstream side of the pump .

[0027] A three-way valve 13 is provided at the connection between the downstream end of the bypass passage 22 and the main passage 21 . <Ion exchanger 30> The bypass passage 22 is provided with an ion exchanger 30 .

[0028] The ion exchanger 30 includes a first supply passage 33, a second supply passage , a first storage section 31, a second storage section 32, a switching valve 35, a first discharge passage 37, and a second discharge passage . The bypass passage 22 branches into a first supply passage 33 and a second supply passage 34 midway. A switching valve 35 is provided at the branch point between the first supply passage 33 and the second supply passage 34. The switching valve 35 switches the manner in which the cooling water flows into the first supply passage 33 and the second supply passage 34. The switching valve 35 is, for example, an electromagnetic switching valve.

[0029] The first storage section 31 is connected to the first supply passage 33. The second storage section 32 is connected to the second supply passage 34. That is, the first storage section 31 and the second storage section 32 are arranged in parallel. In this embodiment, the first storage section 31 and the second storage section 32 are configured by containers 51, 52 that are separate from each other.

[0030] A first discharge passage 37 is connected to the first storage portion 31. A second discharge passage 38 is connected to the second storage portion 32. The first discharge passage 37 and the second discharge passage 38 join together midway.

[0031] The first storage section 31 and the second storage section 32 store an anion exchange resin that removes anions contained in the cooling water by ion exchange, and a cation exchange resin that removes cations contained in the cooling water by ion exchange.

[0032] The cation exchange resin is a well-known strongly acidic cation exchange resin. The first storage section 31 mainly contains a first anion exchange resin as an anion exchange resin. The first anion exchange resin is a strongly basic anion exchange resin of OH type. In the first storage section 31 of this embodiment, only the first anion exchange resin is contained as an anion exchange resin.

[0033] The second storage section 32 mainly contains a second anion exchange resin, which has higher heat resistance and a smaller ion exchange capacity than the first anion exchange resin. The second anion exchange resin is a carbonate-type strongly basic anion exchange resin. In the second storage section 32 of this embodiment, only the second anion exchange resin is contained as the anion exchange resin.

[0034] <Temperature detection unit 41> 1, the temperature detection unit 41 is a sensor that detects the temperature of the cooling water. The temperature detection unit 41 is preferably provided in the cooling circuit 20 downstream of the fuel cell 10 and upstream of the ion exchanger 30. The temperature detection unit 41 in this embodiment is provided in the main passage 21.

[0035] <Control unit 40> As shown in FIG. 1, the control unit 40 is electrically connected to the electric fan 12b of the radiator 12, the three-way valve 13, the pump 14, a temperature detection unit 41, and the switching valve 35.

[0036] The control unit 40 controls the driving of the pump 14, thereby controlling the manner in which the cooling water is pumped from the pump 14. The control unit 40 controls the driving of the electric fan 12b of the radiator 12, thereby adjusting the temperature of the refrigerant flowing through the refrigerant piping, and thus adjusting the temperature of the cooling water.

[0037] The control unit 40 controls the operation of the three-way valve 13, thereby adjusting the ratio between the amount of cooling water flowing from the ion exchanger 30 to the pump 14 side through the three-way valve 13 and the amount of cooling water flowing from the radiator 12 to the pump 14 side through the three-way valve 13.

[0038] The control unit 40 controls the switching valve 35 based on the temperature of the cooling water detected by the temperature detection unit 41 . The control unit 40 switches the switching valve 35 so that the cooling water flows into the first supply passage 33 when the temperature of the cooling water is lower than a predetermined temperature that is set based on the heat resistance temperature of the first anion exchange resin.

[0039] On the other hand, when the temperature of the cooling water is equal to or higher than the predetermined temperature, the control unit 40 switches the switching valve 35 so that the cooling water flows into the second supply passage . The predetermined temperature in this embodiment is set to the heat-resistant temperature (for example, 60° C.) of the first anion exchange resin.

[0040] Next, the operation of this embodiment will be described. 1, when the temperature of the cooling water is lower than a predetermined temperature, the switching valve 35 is controlled through the control unit 40, and the cooling water flows into the first supply passage 33. This allows the anions contained in the cooling water to be efficiently removed by ion exchange using the first anion exchange resin mainly contained in the first storage unit 31. In addition, since cooling water having a temperature lower than a predetermined temperature is supplied to the first anion exchange resin in the first storage unit 31, thermal deterioration of the first anion exchange resin can be effectively suppressed.

[0041] 1, when the temperature of the cooling water is equal to or higher than the predetermined temperature, the switching valve 35 is controlled via the control unit 40 to cause the cooling water to flow into the second supply passage 34. This makes it possible to remove anions contained in the cooling water by ion exchange using the second anion exchange resin mainly accommodated in the second accommodation unit 32 while suppressing thermal deterioration of the second anion exchange resin.

[0042] In this way, when the temperature of the cooling water is low, ion exchange is performed using the first storage section 31, which mainly contains the first anion exchange resin, which has a larger ion exchange capacity but a lower heat resistance than the second anion exchange resin. On the other hand, when the temperature of the cooling water is high, ion exchange is performed using the second storage section 32, which mainly contains the second anion exchange resin, which has a smaller ion exchange capacity but a higher heat resistance than the first anion exchange resin.

[0043] Next, the effects of this embodiment will be described. (1) When the temperature of the cooling water is lower than a predetermined temperature, the control unit 40 controls the switching valve 35 to allow the cooling water to flow into the first supply passage 33. On the other hand, when the temperature of the cooling water is equal to or higher than the predetermined temperature, the control unit 40 controls the switching valve 35 to allow the cooling water to flow into the second supply passage 34.

[0044] According to such a configuration, the above-mentioned effect is achieved, and therefore it is possible to contribute to a reduction in the total amount of anion exchange resin contained in the ion exchanger 30. (2) The switching valve 35 is configured to switch the manner in which the cooling water flows into the first supply passage 33 and the second supply passage .

[0045] According to this configuration, it is possible to achieve an effect similar to the effect (1) above. (3) The first storage section 31 and the second storage section 32 are constituted by containers 51, 52 which are separate from each other.

[0046] According to this configuration, it is possible to use existing ion exchangers as the first storage section 31 and the second storage section 32. Therefore, the ion exchanger 30 can be easily realized.

[0047] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0048] In the present embodiment, the first storage section 31 and the second storage section 32 are configured as containers 51, 52 that are separate from each other, but the present invention is not limited to this. 2 and 3, for example, the inside of one container 151 may be divided into two by a partition 150 to form a first container section 131 and a second container section 132. In this case, the size of the ion exchanger 130 can be reduced while arranging the two container sections 131 and 132 in parallel.

[0049] Moreover, the switching valve 135 may be configured by a temperature-sensitive valve such as a bimetal. In this case, when the temperature of the cooling water is lower than a predetermined temperature set based on the heat resistance temperature of the first anion exchange resin, the switching valve 135 deforms in response to the temperature of the cooling water, causing the cooling water to flow into the first supply passage 133. When the temperature of the cooling water is equal to or higher than the predetermined temperature, the switching valve 135 deforms in response to the temperature of the cooling water, causing the cooling water to flow into the second supply passage 134. Even in this case, the same effect as effect (1) of the above embodiment can be achieved.

[0050] In the present embodiment, the anion exchange resin accommodated in the first storage section 31 is the first anion exchange resin alone, but is not limited thereto. If the first anion exchange resin is mainly accommodated, the anion exchange resin may be mixed with an anion exchange resin different from the first anion exchange resin. Similarly, for the second anion exchange resin, the anion exchange resin accommodated in the second storage section 32 is the second anion exchange resin alone, but is not limited thereto. If the second anion exchange resin is mainly accommodated, the anion exchange resin may be mixed with an anion exchange resin different from the second anion exchange resin. [Explanation of symbols]

[0051] 10…fuel cell 11...Fuel cell stack 11a…Supply route 11b…Discharge path 11c…Internal flow passage 12…Radiator 12a...Heat exchange section 12b…Electric fan 13...Three-way valve 14…Pump 20…Cooling circuit 21…Main passage 22...Bypass passage 30,130…Ion exchanger 31,131…First storage section 32,132…Second storage section 33,133…1st supply passage 34,134…Second supply passage 35,135...Switching valve 37…1st discharge passage 38…Second discharge passage 40...Control unit 41...Temperature detection section 51, 52, 151…container 150…Partition

Claims

1. An ion exchanger provided in a cooling circuit through which cooling water for cooling a fuel cell flows, the ion exchanger including an anion exchange resin for removing anions contained in the cooling water by ion exchange, A first storage section that mainly stores a first anion exchange resin; a second storage section arranged in parallel with the first storage section and mainly storing a second anion exchange resin having a higher heat resistance and a smaller ion exchange capacity than the first anion exchange resin; a first supply passage and a second supply passage that supply the cooling water to the first storage portion and the second storage portion, respectively; a switching valve that switches an inflow state of the cooling water into the first supply passage and the second supply passage, Ion exchanger for fuel cells.

2. The first storage section and the second storage section are configured by containers that are separate from each other.

2. The ion exchanger for a fuel cell according to claim 1.

3. The first storage section and the second storage section are formed by dividing the inside of one storage container into two sections.

2. The ion exchanger for a fuel cell according to claim 1.

4. A fuel cell stack; a cooling circuit for supplying cooling water to the fuel cell stack; The ion exchanger according to any one of claims 1 to 3, which is provided in the cooling circuit; a temperature detection unit for detecting a temperature of the cooling water; A control unit that controls the switching valve, the control unit controls the switching valve so that the cooling water flows into the first supply passage when the temperature of the cooling water is lower than a predetermined temperature set based on the heat resistance temperature of the first anion exchange resin, and controls the switching valve so that the cooling water flows into the second supply passage when the temperature of the cooling water is equal to or higher than the predetermined temperature. Fuel cell system.

5. A fuel cell stack; a cooling circuit for supplying cooling water to the fuel cell stack; The ion exchanger according to any one of claims 1 to 3 is provided in the cooling circuit, the switching valve is a temperature-sensitive valve that deforms in response to the temperature of the cooling water, and when the temperature of the cooling water is lower than a predetermined temperature that is set based on the heat resistance temperature of the first anion exchange resin, the switching valve deforms so that the cooling water flows into the first supply passage, whereas when the temperature of the cooling water is equal to or higher than the predetermined temperature, the switching valve deforms so that the cooling water flows into the second supply passage. Fuel cell system.

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