The square atmospheric hydrogen electrolyzer has a structure similar to that of a chlor-alkali electrolyzer, featuring a square tank body that includes a cathode half-shell (electrode, support structure), an anode half-shell (electrode, support structure), a diaphragm, gaskets, feed headers, feed pipes, outlet pipes, and outlet headers.

Compared to high-pressure systems, the hydrogen leakage rate in atmospheric systems is significantly reduced, offering better safety. Additionally, the design of square electrolyzers does not need to account for pressure resistance, resulting in lower strength requirements for end plates, frames, and other components, which saves material costs. As an efficient water electrolysis hydrogen production device, the square electrolyzer occupies an important position in the field of new energy due to its unique design and advantages.

I. Key Components of the Square Water Electrolysis Hydrogen Production System

1.Electrolyzer

Electrodes: Coated with precious metal catalysts on the anode and cathode surfaces to enhance the efficiency of electrochemical reactions.

Diaphragm: Located between the electrodes, it serves to separate hydrogen and oxygen while allowing ions to pass through. High-performance composite diaphragm materials are typically used.

Tank Body: Used to support the electrodes and diaphragm, it possesses good sealing performance and sufficient mechanical strength to operate stably under atmospheric or slightly positive pressure conditions and withstand fluctuations in temperature and pressure.

2.Power Supply System

Responsible for providing direct current to the electrolyzer, including transformers and rectifying equipment that convert alternating current into the direct current required by the electrolyzer, ensuring continuous and stable output of voltage and current.

3.Gas-Liquid Separation and Treatment System

Gas Separation Device: Used to separate the hydrogen and oxygen produced in the electrolyzer from the electrolyte.

Gas Purification System: Purifies the separated hydrogen to remove potential impurities such as moisture, oxygen, and other gases, thereby improving hydrogen purity.

Liquid Circulation System: Responsible for circulating the electrolyte to ensure even distribution within the electrolyzer and maintain optimal electrolysis efficiency. It also replenishes water consumed during electrolysis to maintain the concentration and level of the electrolyte.

4.Control System

Monitors and regulates the entire hydrogen production process through sensors, controllers, and actuators. Sensors collect real-time parameters such as temperature, pressure, liquid level, current, and voltage. The controller analyzes the data based on preset logic and outputs commands, while actuators adjust variables such as power output and fluid flow to ensure safe, stable, and efficient system operation.

5.Auxiliary Equipment

Piping and Valves: Used to connect various equipment components and transport gases, liquids, and electricity. Valves control the flow, pressure, and direction of gases and liquids to ensure normal operation and safe functioning of the system.

Cooling System: During electrolysis, a certain amount of heat is generated, which must be dissipated through the cooling system to maintain the electrolyzer's temperature within an appropriate range. Water cooling is typically used for this purpose.

Hydrogen Storage Device: Stores the produced hydrogen for subsequent use or transportation. Types of hydrogen storage devices include high-pressure hydrogen storage tanks, liquid hydrogen tanks, and metal hydride hydrogen storage devices, with the choice depending on specific application needs and scenarios.

II. Characteristics of Square Electrolyzers

1.High Current Density

Square electrolyzers can easily achieve current densities of 10,000 A/m² or even higher, compared to 4,000 A/m² for circular electrolyzers. This translates to faster hydrogen production rates and lower energy consumption per unit. High current density not only reduces the amount of electrolyte required and the volume of the electrolyzer but also minimizes equipment footprint and investment costs.

2.Uniform Flow Field Distribution

The square electrolyzer employs a zero-gap electrode plate structure and low-fluid-resistance distributed flow channels, ensuring uniform internal flow field distribution and direct fluid flow. This effectively avoids current drift and concentration, suppressing stray currents.

3.High Safety

The square electrolyzer adopts an atmospheric pressure design, which significantly reduces the hydrogen leakage rate compared to high-pressure systems, enhancing safety. Its modular design facilitates decentralized relocation, reduces hoisting difficulty, and simplifies maintenance and inspection.

4.Modular Assembly

The modular design of the square electrolyzer improves the ease of installation, maintenance, and replacement. Individual cell slots are independent of each other, making disassembly, inspection, and maintenance more convenient in the later stages.