Integrated pure water preparation, supply and circulation device of PEM electrolytic bath

Abstract

The utility model discloses an integrated pure water preparation, supply and circulation device of a PEM electrolytic bath, and relates to the technical field of PEM electrolytic baths, the integrated pure water preparation, supply and circulation device comprises a pure water preparation unit, the pure water preparation unit comprises a deionized resin bed, an EDI module and a precision filter, and inlets of the deionized resin bed and the EDI module are respectively connected with an outlet of a water supply pipeline through two branch pipes; the water circulation unit comprises an intercooler, a gas-liquid separator, a water storage tank and a circulating water pump which are connected in sequence, and an outlet of the circulating water pump is connected with the water supply pipeline; and conductivity sensors are arranged on the water supply pipeline and the two branch pipes. The deionization resin bed and the EDI module are combined for use, unelectrolyzed water is input into the pure water preparation unit from the water circulation unit to be purified and recycled, the pure water preparation unit is efficiently utilized, and the influence of falling of a catalyst of a membrane electrode and metal precipitation of all parts on water quality is effectively avoided. And the conductivity sensor monitors the attenuation condition of the membrane electrode.

Description

Technical Field

[0001] This utility model relates to the technical field of PEM electrolyzers, specifically to an integrated pure water hydrogen production and replenishment circulation device for PEM electrolyzers. Background Technology

[0002] A PEM (Proton Exchange Membrane) electrolyzer is a device that uses a proton exchange membrane to electrolyze water. When a direct current is applied, water undergoes an electrochemical reaction to produce hydrogen and oxygen. It consists of one or more proton exchange membrane electrolyzers connected in series or parallel, and features high hydrogen purity, high current density, fast response speed, wide operating temperature range, and high working pressure.

[0003] PEM electrolyzers require a water conditioning system for necessary treatment of supply and return water, mainly including the following: 1. Makeup water tank; 2. Feed water pump; 3. Deionized water production unit; 4. Anode circulation loop, including: a water purification device, mainly an ion exchange resin bed, used to maintain water quality at the required level to minimize the risk of chemical contamination of the electrolyzer; an oxygen / water separator for initial separation of residual liquid water in the outlet gas stream; a demister for further removal of small droplets from the outlet gas stream; 5. Cathode circulation loop, including at least a hydrogen / water separator and a demister; sometimes also including a circulation pump to meet cathode-side thermal management requirements.

[0004] For example, Chinese invention patent number 202110861742.3 discloses a differential pressure pure water electrolysis hydrogen production system, including: an electrolytic cell having a first end pressure plate, a second end pressure plate, a water inlet, a hydrogen outlet, an oxygen outlet, and a drain outlet; a water supply assembly including a raw material water tank, a first water supply pipe, and a second water supply pipe; a hydrogen assembly including a hydrogen separation cooler, a hydrogen venting pipe assembly, a hydrogen gas supply pipe, a pressure sensor, a liquid level sensor, and a hydrogen purity analyzer; and an oxygen assembly. It includes an oxygen heat exchanger, an oxygen cooler, an oxygen vent pipe assembly, and an oxygen purity analyzer; a cooling water pipe assembly, including a cooling water inlet pipe and a cooling water outlet pipe, through which cooling water can enter the oxygen heat exchanger, the oxygen cooler, and the hydrogen separation cooler for heat exchange; and a control unit, which is electrically connected to a pressure sensor, a liquid level sensor, a hydrogen purity analyzer, an oxygen purity analyzer, an outlet water temperature sensor, and multiple solenoid valves installed in the hydrogen vent pipe assembly, the hydrogen supply pipe, the return water pipe, and the cooling water pipe assembly.

[0005] Furthermore, Chinese invention patent number 202211538762.8 discloses a pure water electrolysis hydrogen production system, including a pure water tank, an external circulation pump, a heat exchanger, an external filtration device, an internal circulation filtration system, and a differential pressure PEM electrolyzer. The external filtration device includes a first polishing mixed bed resin tank and a first precision filter. The outlet of the first polishing mixed bed resin tank is connected to the inlet of the first precision filter, the outlet of the first precision filter is connected to the inlet of the internal circulation filtration system, and the outlet of the internal circulation filtration system is connected to the pure water inlet of the differential pressure PEM electrolyzer. The internal circulation filtration system includes an internal circulation buffer tank, an internal circulation pump, a second polishing mixed bed resin tank, and a second precision filter. This pure water electrolysis hydrogen production system can reduce the problem of low pure water resistivity caused by external air pollution, temperature rise, and catalyst shedding from the membrane electrode surface, thereby extending the service life of the differential pressure PEM electrolyzer and reducing pure water waste.

[0006] However, the water supply and return systems currently used in PEM electrolyzers are separate units, operating independently without making proper use of the water purification unit on the supply side. After prolonged hydrogen production, trace amounts of catalyst may detach from the membrane electrode in the PEM electrolyzer, causing membrane electrode degradation. The existing water supply and return systems for PEM electrolyzers cannot monitor this degradation. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and to provide an integrated pure water preparation, replenishment and circulation device for a PEM electrolyzer.

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] An integrated pure water preparation, replenishment, and circulation device for a PEM electrolyzer includes: a pure water preparation unit, which comprises a deionization resin bed, an EDI module (Electrodeionization, continuous electro-desalination module), and a precision filter. The inlets of the deionization resin bed and the EDI module are respectively connected to the outlets of a water supply pipeline through two branch pipes. The outlets of the two branch pipes are both connected to the inlet of the precision filter, and the outlet of the precision filter is connected to the inlet of the PEM electrolyzer.

[0010] The water circulation unit includes an intercooler, a gas-liquid separator, a water storage tank, and a circulating water pump connected in sequence. The inlet of the intercooler is connected to the water and oxygen outlet of the PEM electrolysis cell, and the outlet of the circulating water pump is connected to the water supply pipeline.

[0011] The conductivity sensor is installed on both the water supply pipe and the two branch pipes.

[0012] By adopting the above technical solution, the pure water preparation unit and the water circulation unit are used in combination. Water output from the PEM electrolyzer is directly input into the pure water preparation unit for purification and reuse after passing through the water circulation unit. The conductivity sensor can monitor the water conductivity in the pure water preparation unit and the water circulation unit in real time, providing feedback on whether there is catalyst shedding from the membrane electrode in the PEM electrolyzer, and whether there is metal deposition in various components within the pure water preparation unit and the water circulation unit.

[0013] Preferably, valves are connected to both the water supply pipeline and the two branch pipes.

[0014] By adopting the above technical solution, valves are used in the water supply pipeline and two branch pipes, enabling free combination of the deionized resin bed and EDI module.

[0015] Preferably, the precision filter is a 0.2μm precision filter.

[0016] By adopting the above technical solution, the 0.2μm precision filter can filter out impurities as small as 0.2μm.

[0017] Compared with related technologies, the integrated pure water preparation, replenishment, and circulation device for PEM electrolyzers provided by this utility model has the following beneficial effects:

[0018] 1. This application combines a pure water preparation unit and a water circulation unit. Water output from the PEM electrolyzer is directly fed into the pure water preparation unit by the water circulation unit for purification and recycling. The pure water preparation unit can purify the circulating water into pure water, effectively avoiding the impact of catalyst shedding from the membrane electrode and metal precipitation from various components on water quality.

[0019] 2. The conductivity sensor monitors the water conductivity in the pure water preparation unit circuit and the water circulation unit circuit in real time, thereby revealing the attenuation of the membrane electrode in the PEM electrolyzer. Attached Figure Description

[0020] Figure 1 A schematic diagram of the integrated pure water preparation, replenishment, and circulation device for a PEM electrolyzer.

[0021] Reference numerals in the attached diagram: 1. Water supply pipeline; 2. Branch pipe; 3. Deionized resin bed; 4. EDI module; 5. Precision filter; 6. PEM electrolytic cell; 7. Intercooler; 8. Gas-liquid separator; 9. Water storage tank; 10. Circulating water pump; 11. Conductivity sensor; 12. Valve. Detailed Implementation

[0022] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art are within the protection scope of this utility model.

[0023] In the description of this utility model, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and do not require that this utility model be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this utility model. The terms "connected" and "linked" used in this utility model should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0024] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. Example

[0025] This embodiment provides an integrated pure water preparation, replenishment, and circulation device for a PEM electrolyzer, including a pure water preparation unit, a water circulation unit, and a conductivity sensor 11.

[0026] The pure water preparation unit includes a deionization resin bed 3, an EDI module 4, and a precision filter 5. The inlets of the deionization resin bed 3 and the EDI module 4 are connected to the outlets of the water supply line 1 via two branch pipes 2. External water is first introduced into the water supply line 1, and can then be selectively introduced into the two branch pipes 2. Depending on the water quality, the deionization resin bed 3 and the EDI module 4 can be used in conjunction to maximize water purification efficiency. The water supply line 1 can continuously supply water to the pure water preparation unit.

[0027] A deionization resin bed 3 is a device used to remove ions from water. Its core component is an ion exchange resin, a high-molecular-weight polymer with functional groups, such as sulfonic acid groups and carboxyl groups for cation exchange resins, and quaternary ammonium groups for anion exchange resins. When water containing ions passes through the resin bed, the exchangeable ions on the resin exchange with the ions in the water.

[0028] EDI Module 4 is a novel ultrapure water preparation technology. It combines ion exchange resin and electrodialysis to remove ionic impurities, including cations and anions, from water to obtain high-purity water. Its working principle is based on the directional migration of ions under the influence of an electric field. EDI Module 4 contains cation and anion exchange membranes that divide the module into multiple compartments. Driven by a DC electric field, cations in the water migrate towards the cathode, and anions migrate towards the anode. Simultaneously, the ion exchange resin filling the module accelerates the ion migration and exchange process.

[0029] The outlets of both branch pipes 2 are connected to the inlet of the precision filter 5. After water treatment by the deionized resin bed 3 and / or EDI module 4, it is then fed into the precision filter 5 for further filtration to form pure water. The outlet of the precision filter 5 is connected to the inlet of the PEM electrolyzer 6 to supply water to the PEM electrolyzer 6.

[0030] The water circulation unit includes an intercooler 7, a gas-liquid separator 8, a water storage tank 9, and a circulating water pump 10 connected in sequence. The intercooler 7 cools the oxygen and water output from the PEM electrolyzer 6. The gas-liquid separator 8 separates the oxygen and water, and the separated water is fed into the water storage tank 9, and then fed into the water supply pipeline 1 via the circulating water pump 10, thus realizing water recycling. The pure water preparation unit can be fully utilized; the filtration required for the downstream circulation section of the PEM electrolyzer 6 can be connected to the upstream pure water preparation unit for filtration, which saves money and volume, and increases the overall system stability.

[0031] Conductivity sensors 11 are installed on both the water supply pipeline 1 and the two branch pipes 2. Specifically, one conductivity sensor 11 is installed on the water supply pipeline 1, and one conductivity sensor 11 is installed on each of the two branch pipes 2, located downstream of the deion exchange resin bed and the EDI module 4, respectively. The conductivity sensors 11 can monitor the water conductivity in the pure water preparation unit and the water circulation unit in real time, providing feedback on whether there is catalyst shedding from the membrane electrode in the PEM electrolyzer 6, and whether there is metal deposition in various components within the pure water preparation unit and the water circulation unit.

[0032] The above are merely preferred embodiments of the present invention and do not limit the implementation methods and protection scope of the present invention. The present invention also has the following embodiments based on the above:

[0033] In this embodiment, valves 12 are connected to both the water supply pipeline 1 and the two branch pipes 2. Specifically, one valve 12 is provided on the water supply pipeline 1, and two valves 12 are provided on each of the two branch pipes 2. The two valves 12 on the branch pipes 2 are located upstream and downstream of the deionized resin bed 3 or the EDI module 4, respectively.

[0034] In this embodiment, the precision filter 5 is a 0.2μm precision filter, which can filter out impurities as small as 0.2μm.

[0035] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0036] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be within the scope of protection of the pending claims of the present utility model.

Claims

1. An integrated pure water preparation, replenishment, and circulation device for a PEM electrolyzer, characterized in that, include: The pure water preparation unit includes a deionized resin bed (3), an EDI module (4), and a precision filter (5). The inlets of the deionized resin bed (3) and the EDI module (4) are respectively connected to the outlet of the water supply pipeline (1) through two branch pipes (2). The outlets of the two branch pipes (2) are connected to the inlet of the precision filter (5). The outlet of the precision filter (5) is connected to the inlet of the PEM electrolysis cell (6). The water circulation unit includes an intercooler (7), a gas-liquid separator (8), a water storage tank (9), and a circulating water pump (10) connected in sequence. The inlet of the intercooler (7) is connected to the water and oxygen outlet of the PEM electrolysis cell (6), and the outlet of the circulating water pump (10) is connected to the water supply pipeline (1). The conductivity sensor (11) is installed on both the water supply pipe (1) and the two branch pipes (2).

2. The integrated pure water preparation, replenishment, and circulation device for the PEM electrolyzer according to claim 1, characterized in that: Valves (12) are connected to both the water supply pipe (1) and the two branch pipes (2).

3. The integrated pure water preparation, replenishment, and circulation device for the PEM electrolyzer according to claim 1, characterized in that: The precision filter (5) is a 0.2μm precision filter.

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