Hydrogen safety knowledge involves many aspects, the following is a detailed summary of hydrogen safety knowledge:
i. Nature of Hydrogen
- physical Properties:
- hydrogen is a colorless, odorless, tasteless gas that is difficult to liquefy. Liquid hydrogen is colorless and transparent, easy to diffuse and penetrate. Slightly soluble in water, insoluble in ethanol, ether.
- Hydrogen is lighter than air and has a much higher diffusion rate than air. At room temperature and pressure is a colorless, odorless, non-toxic gas, with very low solidification and boiling point.
- Chemical Properties:
- extremely flammable, can form an explosive mixture when mixed with air, and explode when exposed to heat or open flame. The explosion limit is 4% ~ 75% (volume ratio), and the spontaneous combustion temperature is 500 ℃.
- When burning in the air, the flame is blue (also known as colorless) and is not easy to be found.
- With fluorine, chlorine, bromine and other halogen will react violently. It is a simple asphyxiating gas that causes anoxic asphyxia only at high concentrations due to a decrease in the partial pressure of oxygen in the air. At very high partial pressures, an anesthetic effect is exhibited.
Safety of hydrogen use
- storage safety:
- hydrogen should be stored in pressure vessels or specially designed tanks. These equipment should meet the requirements of standards and regulations and undergo inspection procedures.
- Storage containers shall be kept in isolation from oxygen, compressed air, halogen, oxidant and other combustion-supporting gas cylinders.
- Hydrogen leak detection alarm shall be set at the hydrogen storage site, and explosion-proof ventilation system and equipment shall be used, and direct sunlight shall be avoided.
- Operation safety:
- operators must be specially trained, strictly abide by the operation procedures, master the operation skills, and have the knowledge of emergency disposal.
- Places using hydrogen must be adequately ventilated or ventilated to avoid hydrogen accumulation in the room.
- In places where hydrogen is used, open flames are prohibited, and non-sparking tools and equipment are required. At the same time, electrostatic discharge from power tools and equipment should be avoided.
- The hydrogen outlet must not be near the air inlet to prevent hydrogen from flowing into the room.
- Regularly check the hydrogen pipeline and gas circuit valves to ensure that there is no leakage.
- Before using high-pressure gas, attention must be paid to the full ventilation of the room and the leak detection of the pipeline.
- Emergency Disposal:
- in case of hydrogen leakage, alarm shall be given immediately and a warning area shall be established. Personnel in the leakage area shall be evacuated to the upper wind and isolated.
- Cut off the leakage gas source, and use anti-static tools for leakage stoppage and emergency repair.
- Eliminate fire, stop all fire operations and eliminate activities that may produce sparks.
- Ventilate the leakage contaminated area. If the leakage cannot be cut off in time, steam should be used for dilution to prevent hydrogen from accumulating and forming explosive gas mixture.
- If the leakage occurs indoors, it is advisable to use the suction system to discharge the leaked hydrogen to the outside and ventilate the room.
- High concentrations of hydrogen can cause suffocation, so the suffocated person should be moved to a well-ventilated place in time for artificial respiration and prompt medical treatment.