Hydrogen Isotope Separation System

Abstract

To provide a hydrogen isotope separation system capable of achieving simplification of a configuration and suppression of an increase in an arrangement space.SOLUTION: A hydrogen isotope separation system 10 includes a fuel battery cell 15 having an ion exchange membrane 15a, an anode 15b, and a cathode 15c. The hydrogen isotope separation system 10 comprises: an anode supply path 10a for supplying heavy water containing light water to the anode 15b; a heavy water tank 11; an anode-side humidifier 14A; a cathode supply path 10b for supplying an inert gas containing the light water to the cathode 15c; a nitrogen tank 12; and a cathode-side humidifier 14C. The hydrogen isotope separation system 10 includes: an anode-side condensation separator 16 provided on the discharge side of the anode 15b of the fuel battery cell 15; a cathode-side condensation separator 17 provided on the discharge side of the cathode 15c of the fuel battery cell 15; and a refrigerant circuit 30. The refrigerant circuit 30 cools the cathode-side condensation separator 17 by the refrigerant after being used for cooling the anode-side condensation separator 16.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hydrogen isotope separation system. [Background technology]

[0002] In recent years, research and development into fuel cells has been conducted to contribute to energy efficiency, ensuring that more people have access to affordable, reliable, sustainable and advanced energy. Conventionally, for example, systems have been known in which raw water containing heavy water is decomposed using an electrolytic cell having an ion exchange membrane and a catalyst to obtain hydrogen and oxygen with low deuterium and tritium contents (see, for example, Patent Documents 1 and 2). In these systems, the hydrogen and oxygen obtained by the electrolytic cell are supplied to a fuel cell after removing moisture using condensation separators (cooling element devices, etc.) on the anode and cathode sides, respectively. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-11903 [Patent Document 1] Japanese Patent Application Publication No. 2023-13534 Summary of the Invention [Problem to be solved by the invention]

[0004] In fuel cell technology, it is desirable to prevent the refrigerant circuit from becoming too complicated. For example, when a condenser separator is provided on each of the anode and cathode sides, as in the above-mentioned conventional technology, the refrigerant circuit may become too complicated, and it is therefore necessary to simplify the refrigerant circuit and prevent an increase in the installation space.

[0005] The present invention aims to solve the above problems by simplifying the configuration and suppressing an increase in the installation space, which in turn contributes to improving energy efficiency. [Means for solving the problem]

[0006] In order to solve the above problems and achieve the above object, the present invention employs the following aspects. (1): A hydrogen isotope separation system according to one aspect of the present invention (e.g., hydrogen isotope separation system 10 in the embodiments) includes a fuel cell (e.g., fuel cell 15 in the embodiments) having an ion exchange membrane (e.g., ion exchange membrane 15a in the embodiments), an anode (e.g., anode 15b in the embodiments) and a cathode (e.g., cathode 15c in the embodiments) provided on both sides of the ion exchange membrane in the thickness direction, a heavy water supply unit (e.g., anode supply channel 10a, heavy water tank 11, and anode-side humidifier 13 in the embodiments) that supplies heavy water containing light water toward the anode, and an inert gas supply unit that supplies inert gas containing light water to the cathode. The fuel cell includes a supply unit (for example, the cathode supply path 10b, nitrogen tank 12, and cathode-side humidifier 14 in the embodiments), an anode-side condensation separator (for example, the anode-side condensation separator 16 in the embodiments) provided on the discharge side of the anode of the fuel cell, a cathode-side condensation separator (for example, the cathode-side condensation separator 17 in the embodiments) provided on the discharge side of the cathode of the fuel cell, and a refrigerant circuit (for example, the refrigerant circuit 30 in the embodiments) that supplies a refrigerant to the anode-side condensation separator and the cathode-side condensation separator, and the refrigerant circuit cools the cathode-side condensation separator with the refrigerant that has cooled the anode-side condensation separator.

[0007] (2): The hydrogen isotope separation system described in (1) above may include a refrigerant cooler (e.g., refrigerant cooler 31 in the embodiment) that dissipates heat from the refrigerant, and the refrigerant circuit may dissipate heat from the refrigerant after cooling the cathode-side condensation separator using the refrigerant cooler.

[0008] (3) In the hydrogen isotope separation system described in (1) or (2) above, the refrigerant circuit may connect the anode-side condensation separator and the cathode-side condensation separator in series. [Effects of the Invention]

[0009] According to the above (1), by cooling the anode-side condensation separator, which requires a smaller processing volume and heat quantity, prior to cooling the cathode-side condensation separator, which requires a relatively larger processing volume and heat quantity for the condensation reaction, it is possible to prevent the refrigerant circuit from becoming complicated and the installation space from becoming larger.

[0010] In the case of (2) above, the refrigerant can dissipate heat more appropriately and efficiently than, for example, when the refrigerant after cooling the anode-side condensation separator is dissipated heat by a refrigerant cooler.

[0011] In the case of (3) above, the refrigerant circuit can be prevented from becoming complicated and the installation space can be prevented from increasing, compared to when the anode side condensation separator and the cathode side condensation separator are connected in a form other than in series. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a configuration diagram of a hydrogen isotope separation system according to an embodiment of the present invention. [Figure 2] FIG. 3 is a diagram showing an example of an isotope exchange equilibrium reaction in a fuel cell of a hydrogen isotope separation system according to an embodiment of the present invention. [Figure 3] FIG. 2 is a configuration diagram of a refrigerant circuit in the hydrogen isotope separation system according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a hydrogen isotope separation system according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a hydrogen isotope separation system 10 according to an embodiment. As shown in FIG. 1, the hydrogen isotope separation system 10 of the embodiment includes, for example, an anode supply path 10a and a cathode supply path 10b, an anode discharge path 10c and a cathode discharge path 10d, a heavy water tank 11, a nitrogen tank 12, an electrolytic cell 13, an anode-side humidifier 14A and a cathode-side humidifier 14C, a fuel cell stack S consisting of a plurality of fuel cell cells 15, an anode-side condensation separator 16 and a cathode-side condensation separator 17, an anode-side on-off valve 18 and a cathode-side on-off valve 19, an anode-side tank 21 and a cathode-side tank 22.

[0014] The heavy water tank 11 stores, for example, heavy water containing light water (water). The heavy water tank 11 supplies heavy water containing water to the electrolysis cell 13 via an anode supply path 10a provided between the heavy water tank 11 and the fuel cell stack S. For example, the light water (water) 1 H2 16 O), and heavy water is water containing at least one of hydrogen isotopes such as double hydrogen (deuterium: D) and tritium (tritium: T). For example, the heavy water tank 11 supplies heavy water containing water to the electrolysis cell 13. The nitrogen tank 12 stores a gas such as air containing nitrogen gas. The nitrogen tank 12 supplies the nitrogen gas to the fuel cell stack S via a cathode supply passage 10b provided between the nitrogen tank 12 and the fuel cell stack S.

[0015] The electrolytic cell 13 is provided on the anode supply path 10a between the heavy water tank 11 and the anode-side humidifier 14A. The electrolytic cell 13 electrolyzes heavy water containing water supplied from the heavy water tank 11 to produce hydrogen (H2), deuterium (D2), tritium (T2), and the like, and supplies these to the anode-side humidifier 14A. The anode-side humidifier 14A is provided in the anode supply path 10a between the electrolytic cell 13 and the fuel cell stack S. The anode-side humidifier 14A humidifies hydrogen (H2), deuterium (D2), tritium (T2), etc. supplied from the electrolytic cell 13 with, for example, water vapor and liquid water, and supplies the humidified hydrogen to the fuel cell stack S. The cathode-side humidifier 14 is provided in the cathode supply passage 10b. The cathode-side humidifier 14 humidifies the nitrogen gas supplied from the nitrogen tank 12 with, for example, water vapor and liquid water, and supplies the humidified nitrogen gas to the fuel cell stack S.

[0016] The fuel cell stack S includes, for example, a plurality of stacked fuel cell units 15. Each fuel cell unit 15 includes, for example, an ion exchange membrane (electrolyte membrane) 15a, an anode 15b and a cathode 15c provided on either side of the ion exchange membrane 15a in the thickness direction, an anode-side flow path 15d, and a cathode-side flow path 15e. The ion exchange membrane 15a comprises, for example, a proton exchange membrane or an anion exchange membrane. The anode 15b comprises, for example, a platinum-based anode catalyst and a gas diffusion layer. The cathode 15c comprises, for example, a platinum-based cathode catalyst and a gas diffusion layer. The anode-side flow path 15d is formed between the anode 15b and the anode 15b by, for example, an anode-side separator, and communicates with the anode supply path 10a and the anode discharge path 10c outside the fuel cell stack S. The cathode-side flow path 15e is formed between the cathode 15c and the cathode 15c by, for example, a cathode-side separator, and communicates with the cathode supply path 10b and the cathode discharge path 10d outside the fuel cell stack S.

[0017] FIG. 2 is a diagram showing an example of an isotope exchange equilibrium reaction in the fuel cell 15 of the hydrogen isotope separation system 10 according to the embodiment. 2, in the fuel cell 15, an isotope exchange reaction occurs between water and hydrogen gas at the anode 15b, to which heavy water containing water is supplied, and the cathode 15c, to which nitrogen gas is supplied, and hydrogen isotopes such as deuterium (D) move to the oxide side. In addition, deuterium (D) and tritium (T) move from the anode 15b side to the cathode 15c side through the ion exchange membrane 15a. For example, the exchange reactions shown in the following formulas (1) and (2) occur at the anode 15b, and the exchange reaction shown in the following formula (2) occurs at the cathode 15c. Note that the exchange reactions at the anode 15b and the cathode 15c include exchange reactions obtained by replacing deuterium (D) with tritium (T) in each of the following formulas (1) and (2). Furthermore, (g) in the following formula (2) represents the state of gas, vapor, etc.

[0018]

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[0019]

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[0020] In the fuel cell 15, for example, heavy water (HDO), deuterated hydrogen (HD), tritiated water (HTO), and tritiated hydrogen (HT) move from the anode 15b side to the cathode 15c side through the ion exchange membrane 15a. In the fuel cell 15, for example, water (H2O) moves from the cathode 15c side to the anode 15b side through the ion exchange membrane 15a. In the cathode 15c of the fuel cell 15, for example, heavy water (HDO) and tritiated water (HTO) are discharged to the cathode discharge channel 10d together with water (H2O) carried by nitrogen.

[0021] The anode-side condensate separator 16 is provided in the anode discharge passage 10c. The cathode-side condensate separator 17 is provided in the cathode discharge passage 10d. Each of the anode-side condensate separator 16 and the cathode-side condensate separator 17 separates the fluid discharged from the fuel cell 15 into a gas component and a liquid component. The liquid component is, for example, light water (water) and heavy water separated from the fluid by condensation. For example, the gas components separated in the anode-side condensation separator 16 are hydrogen (H), deuterium (D), and tritium (T), and the liquid components are light water (H0) and heavy water (HDO, HTO). The anode-side condensation separator 16, for example, discharges the gas components to the outside and discharges the liquid components toward the anode-side tank 21. For example, the gas components separated by the cathode-side condensate separator 17 are nitrogen (N2) or air, and the liquid components are light water (HO) and heavy water (HDO, HTO). The cathode-side condensate separator 17, for example, discharges the gas components to the outside and discharges the liquid components toward the cathode-side tank 22.

[0022] FIG. 3 is a configuration diagram of the refrigerant circuit 30 in the hydrogen isotope separation system 10 according to the embodiment. 3, the hydrogen isotope separation system 10 includes, for example, a refrigerant circuit 30 that is connected to the anode-side condensation separator 16 and the cathode-side condensation separator 17 and that circulates a refrigerant. The refrigerant circuit 30 includes, for example, a refrigerant cooler 31 that cools the refrigerant. The refrigerant circuit 30 connects in series, for example, a refrigerant cooler 31, an anode-side condensation separator 16, and a cathode-side condensation separator 17, in that order from upstream to downstream along the direction of refrigerant flow. The refrigerant cooled by the refrigerant cooler 31 to a first temperature T1 is first supplied to the anode-side condensation separator 16, and the refrigerant at a second temperature T2 (>T1) after cooling the anode-side condensation separator 16 is then supplied to the cathode-side condensation separator 17. The refrigerant at a third temperature T3 (>T2) after cooling the cathode-side condensation separator 17 is returned to the refrigerant cooler 31.

[0023] For example, the amount of condensed water treated in the cathode side condensation separator 17 is set to be relatively larger than the amount of condensed water treated in the anode side condensation separator 16, and therefore the amount of heat required in the cathode side condensation separator 17 is larger than the amount of heat required in the anode side condensation separator 16. As a result, the temperature change ΔT2 (=T2-T3) of the refrigerant in the cathode side condensation separator 17 is relatively larger than the temperature change ΔT1 (=T1-T2) of the refrigerant in the anode side condensation separator 16 (ΔT1<ΔT2).

[0024] 2, the anode-side on-off valve 18 is provided between the anode-side condensate separator 16 and the anode-side tank 21. The cathode-side on-off valve 19 is provided between the cathode-side condensate separator 17 and the cathode-side tank 22. The anode-side on-off valve 18 and the cathode-side on-off valve 19 are, for example, solenoid valves, motor-operated valves, or air-operated valves whose opening and closing and opening degree are controlled, and switch the fluid flow state of the liquid components discharged from the anode-side condensation separator 16 and the cathode-side condensation separator 17. The anode-side tank 21 stores the liquid component discharged from the anode-side condensate separator 16. The cathode-side tank 22 stores the liquid component discharged from the cathode-side condensate separator 17.

[0025] As described above, according to the hydrogen isotope separation system 10 of the embodiment, the anode-side condensation separator 16, which requires a smaller processing volume and heat quantity, is cooled before the cathode-side condensation separator 17, which requires a relatively large processing volume and heat quantity for the condensation reaction, thereby preventing the refrigerant circuit 30 from becoming complicated and the installation space from increasing. The refrigerant that has cooled the cathode-side condensation separator 17 is returned to the refrigerant cooler 31, so that the refrigerant can dissipate heat more appropriately and efficiently than, for example, when the refrigerant that has cooled the anode-side condensation separator 16 is dissipated heat by the refrigerant cooler 31. By connecting the anode side condensation separator 16 and the cathode side condensation separator 17 in series, it is possible to prevent the refrigerant circuit 30 from becoming more complex and the installation space from increasing, compared to, for example, cases where the refrigerant circuit 30 is connected in a manner other than in series.

[0026] The embodiments of the present invention are presented as examples and are not intended to limit the scope of the invention. These embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0027] 10...hydrogen isotope separation system, 10a...anode supply channel (heavy water supply section), 10b...cathode supply channel (inert gas supply section), 10c...anode discharge channel, 10d...cathode discharge channel, 11...heavy water tank (heavy water supply section), 12...nitrogen tank (inert gas supply section), 13...electrolysis cell, 14A...anode side humidifier (heavy water supply section), 14C...cathode side humidifier (inert gas supply section), 15...fuel cell, 15a...ion exchange membrane, 15b...anode, 15c...cathode, 15d...anode side flow path, 15e...cathode side flow path, 16...anode side condensate separator, 17...cathode side condensate separator, 18...anode side on / off valve, 19...cathode side on / off valve, 21...anode side tank, 22...cathode side tank, 30...refrigerant circuit, S...fuel cell stack.

Claims

1. a fuel cell having an ion exchange membrane and an anode and a cathode provided on both sides of the ion exchange membrane in a thickness direction; a heavy water supply unit that supplies heavy water containing light water toward the anode; an inert gas supply unit that supplies an inert gas containing light water to the cathode; an anode-side condensation separator provided on the discharge side of the anode of the fuel cell; a cathode-side condensation separator provided on the discharge side of the cathode of the fuel cell; a refrigerant circuit that supplies a refrigerant to the anode-side condensation separator and the cathode-side condensation separator; Equipped with The refrigerant circuit cools the cathode-side condensation separator with the refrigerant that has cooled the anode-side condensation separator. Hydrogen isotope separation system.

2. a refrigerant cooler that dissipates heat from the refrigerant; The refrigerant circuit dissipates heat of the refrigerant after cooling the cathode-side condensation separator by the refrigerant cooler. The hydrogen isotope separation system of claim 1 .

3. The refrigerant circuit connects the anode side condensation separator and the cathode side condensation separator in series. The hydrogen isotope separation system according to claim 1 or 2.

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