Application of Common Hydrogen Sensors in Hydrogen Concentration Monitoring

In today's world, hydrogen energy is widely recognized as a clean energy source and is increasingly becoming a low-carbon and zero-carbon energy option. A hydrogen fuel cell is a power generation device that directly converts the chemical energy of hydrogen and oxygen into electrical energy, with its basic principle being the reverse reaction of water electrolysis. Hydrogen and oxygen are supplied to the anode and cathode respectively. After hydrogen diffuses outward through the anode and reacts with the electrolyte, the released electrons travel to the cathode via an external load. Hydrogen fuel cells offer three key advantages:

First, they are pollution-free. Hydrogen fuel cells produce no environmental pollutants. Unlike typical traditional backup power solutions that rely on combustion (steam, diesel) or energy storage (batteries), hydrogen fuel cells operate through electrochemical reactions. Conventional combustion systems emit pollutants such as COₓ, NOₓ, SOₓ gases and dust particles. As mentioned above, hydrogen fuel cells only produce water and heat. If hydrogen is generated from renewable energy sources (photovoltaic panels, wind power, etc.), the entire cycle will not produce any harmful substances at all.

Second, they operate silently. Hydrogen fuel cells run quietly with a noise level of only 55 dB, equivalent to normal human conversation. This makes the fuel cells suitable for indoor installation or outdoor areas with noise restrictions.

Third, they feature high efficiency. The power generation efficiency of hydrogen fuel cells can exceed 50%, which stems from their conversion characteristics. Chemical energy is directly converted into electrical energy without intermediate conversion into thermal energy and mechanical energy (via generators).

Thanks to these advantages of hydrogen fuel cells, Boeing successfully test-flew a small aircraft powered by hydrogen fuel cells on April 3, 2008. Boeing claimed this was a milestone in the history of global aviation, demonstrating that the aviation industry will become more powerful and environmentally friendly in the future. The aircraft adopted high-performance and high-efficiency hydrogen fuel cells, proving the application potential of hydrogen fuel cell technology. The fuel system uses hydrogen as fuel, converting it directly into electrical energy through an electrochemical reaction with oxygen in the air without combustion, with water as the only by-product. If hydrogen fuel is produced using renewable energy, the aircraft engine will achieve complete carbon dioxide-free operation.

However, during the production and application of hydrogen fuel cells, there is a certain risk of H₂ leakage from the cells. H₂ leakage will degrade the performance of fuel cells. Moreover, hydrogen is a flammable gas, and excessive accumulation poses a major potential safety hazard. Therefore, it is necessary to detect hydrogen concentration, making the use of hydrogen sensors indispensable.

Hydrogen sensors respond rapidly and accurately to toxic gases, enabling timely alarms when hazards occur. As highly sensitive gas detectors with alarm functions in modern industrial fields, they are designed to adapt to these extremely harsh working environments. The following three common hydrogen gas detectors are mainly used:

Online Hydrogen Detection and Alarm SystemThe online hydrogen detection and alarm system consists of a gas detection alarm controller and fixed hydrogen detectors. The gas detection alarm controller can be placed in a duty room to monitor and control each monitoring point. Hydrogen detectors are installed at locations where gas leakage is most likely to occur, with gas sensors as their core components. Hydrogen detectors convert the hydrogen concentration detected by the sensors into electrical signals, which are transmitted to the gas detection alarm controller via cables. The higher the gas concentration, the stronger the electrical signal. When the gas concentration reaches or exceeds the alarm threshold set by the controller, the system sends out an alarm signal and can activate external devices such as solenoid valves and exhaust fans to automatically eliminate potential hazards. Online hydrogen detection and alarm systems are widely used in petroleum, chemical, metallurgical, power, coal mining, water plant and other environments to effectively prevent explosion accidents.