Electrolysis device, system comprising several electrolysis devices and method for operating the electrolysis device or the system

Abstract

Electrolysis device (10) for generating hydrogen from water with the aid of electrical current, comprising a cell stack (11) made up of a plurality of cell stack elements (12) designed as electrolysis cells, comprising a first pressure sensor (28) for detecting a first hydrogen-side pressure, comprising a second pressure sensor (29) for detecting a second hydrogen-side pressure, and comprising a control device (30) which checks whether the electrolysis device (10) is leaking as a function of the first pressure measured by the first pressure sensor (28), as a function of the second pressure measured by the second pressure sensor (29), and as a function of the electrical current applied to the electrolysis device (10) for the electrolysis.

Claims

[1] Electrolysis device (10) for producing hydrogen from water by means of electric current, with a cell stack (11) comprising several cell stack elements (12) designed as electrolysis cells, characterized by a first pressure sensor (28) for detecting a first hydrogen-side pressure, a second pressure sensor (29) for detecting a second hydrogen-side pressure, a control device (30) which checks whether the electrolysis device (10) is leaking depending on the first pressure measured by the first pressure sensor (28), depending on the second pressure measured by the second pressure sensor (29) and depending on a production parameter, in particular the electrical current and / or the electrical voltage applied to the electrolysis device (10) for electrolysis. [2] Electrolysis device (10) according to claim 1, characterized by opposite end plates (14, 15), wherein the cell stack (11) of the cell stack elements (12) is arranged and pressed between the end plates (14, 15), water supply connections (17), water drainage connections (18) and hydrogen connections (22, 23) formed on the end plates (14, 15), wherein the water supply connections (17) are connectable to at least one water supply line (16), the water discharge connections (18) are connectable to at least one water discharge line (19) and the hydrogen connections (22, 23) are connectable to at least one hydrogen line (24, 25) via a respective coupling device (20, 25, 26), wherein the first pressure sensor (28) is associated with a first hydrogen connection (23), via which hydrogen is discharged from the electrolysis device, or with a hydrogen line (25) coupled to the first hydrogen connection (23), or with a respective coupling device (27), wherein the second pressure sensor (29) is associated with a second hydrogen connection (22), via which no hydrogen is discharged from the electrolysis device, or with a hydrogen line (24) coupled to the second hydrogen connection (22), or with a respective coupling device (26). [3] Electrolysis device (10) according to claim 1 or 2, characterized by that the control device (30) forms an actual pressure difference from the first pressure and the second pressure and checks whether the electrolysis device (10) has a leak depending on the actual pressure difference and the electrical current applied for the electrolysis. [4] Electrolysis device (10) according to claim 3, characterized bythat a characteristic curve for a desired pressure difference is stored in the control unit (30) depending on the electrical current applied for electrolysis, wherein the control unit (3) compares the actual pressure difference dependent on the applied electrical current with a desired pressure difference dependent on the applied electrical current and checks depending on this whether the electrolysis device (10) has a leak. [5] Electrolysis device (10) according to one of claims 1 to 4, characterized by that as the first hydrogen connection (22) and as the second hydrogen connection (23) such hydrogen connections are used which have a maximum geometric distance from one another on the electrolysis device (10). [6] Electrolysis device (10) according to one of claims 1 to 4, characterized bythat the first hydrogen connection (22) and the second hydrogen connection (23) are formed on different end plates (14, 15) of the same cell stack (11) or on different end plates (14, 15) of different cell stacks (11). [7] Electrolysis device (10) according to one of claims 1 to 6, characterized by that an adjustable throttle (31) for throttling the hydrogen flow is assigned to the first hydrogen connection (23) or to the hydrogen line (25) coupled to the first hydrogen connection (23) or to the respective coupling device (27) via which the first hydrogen line (25) is coupled to the first hydrogen connection (23). [8] Electrolysis device (10) according to claim 7, characterized by that the throttle (31) can be switched by the control unit (30). [9] Electrolysis device (10) according to claim 8, characterized bythat the control unit (30) transfers the throttle (31) for the leak test into a first switching state and then into a second switching state, wherein the throttle (31) is further open in the second switching state than in the first switching state. [10] System comprising a plurality of electrolysis devices (10) according to one of claims 1 to 9, characterized by , that when several electrolysis devices (10) are connected in series to form a cascade (33), the control device (30) determines the actual pressure difference across the cascade to check for a leak in the cascade (33), and / or the control device (30) determines the actual pressure difference for each electrolysis device (10) individually to check for an individual leak in the respective electrolysis device (10), when electrolysis devices (10) are connected in parallel, the control unit (30) determines the actual pressure difference for each electrolysis device (10) individually to check for leaks. [11] Method for operating an electrolysis device (10) according to one of claims 1 to 9, or for operating a system comprising a plurality of electrolysis devices (10) according to claim 10, comprising the following steps: Measuring a first pressure with the first pressure sensor (28), Measuring a second pressure with the second pressure sensor (29), Determining an actual pressure difference between the first pressure and the second pressure; Checking the tightness of the electrolysis device (10) or the cascade (33) depending on the actual pressure difference and an electric current applied to the electrolysis device (10) or to the cascade (33) for electrolysis. [12] Method according to claim 11, characterized bythat the tightness is checked depending on the actual pressure difference in such a way that the actual pressure difference is compared with a target pressure difference which is dependent on the applied electrical current and the tightness of the electrolysis device (10) or the cascade (33) is checked depending on this. [13] Method according to claim 11 or 12, characterized by that when a throttle (31) is assigned to the first hydrogen connection (23) or to the hydrogen line (25) coupled to the first hydrogen connection (23) or to the respective coupling device (27), the throttle (31) is only transferred to the first switching state when the first pressure is measured to check the tightness.

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