How are the specific explosion-proof levels of explosion-proof air-conditioning chillers in flammable and explosive places divided?
Publish Time: 2025-01-22
In flammable and explosive places, the explosion-proof level of explosion-proof air-conditioning chillers is a key indicator to ensure their safe operation. These levels are usually divided according to the International Electrotechnical Commission (IEC) and relevant national standards, aiming to prevent explosion accidents caused by factors such as electric sparks and high temperatures.
The explosion-proof level of explosion-proof air-conditioning chillers is mainly distinguished based on many factors such as their design, materials, structure and use environment. Common explosion-proof level classification methods include Exd (flameproof), Exe (increased safety), Exp (positive pressure) and Exia (intrinsically safe).
Exd (flameproof) explosion-proof air-conditioning chillers have a sturdy explosion-proof shell that can withstand the explosion pressure of the internal explosive gas mixture and prevent the internal explosion from spreading to the explosive mixture around the shell. This design enables the unit to protect the safety of the surrounding environment when an explosion occurs.
Exe (increased safety) explosion-proof air-conditioning chillers are designed to improve safety by taking measures to avoid the above phenomena under normal and recognized overload conditions on the equipment structure that will not produce arcs, sparks or high temperatures during normal operation. This type of unit reduces the risk of explosion by optimizing electrical design and strengthening insulation performance.
Exp (positive pressure) explosion-proof air-conditioning chillers prevent explosive mixtures from entering the enclosure or sufficient flammable gases from entering the enclosure through any joints on the enclosure by keeping the pressure of the protective gas inside the equipment enclosure higher than the ambient pressure. This design ensures the cleanliness and safety of the internal environment of the unit.
Exia (intrinsically safe) explosion-proof air-conditioning chillers are designed to prevent the sparks and thermal effects generated by the internal circuit of the equipment under specified test conditions, normal operation or specified fault conditions, from igniting the specified explosive gas mixture. This type of unit has extremely high safety in electrical design and is suitable for places with extremely high explosion hazards.
When selecting an explosion-proof air-conditioning chiller, it is necessary to determine the required explosion-proof level based on the actual working environment and the characteristics of the explosive gas. At the same time, it is also necessary to consider factors such as the unit's cooling efficiency, energy efficiency ratio, convenience of installation and maintenance, and linkage with other explosion-proof equipment. By comprehensively considering these factors, the safe and stable operation of the explosion-proof air-conditioning chiller in flammable and explosive places can be ensured.
