Basic principles for selection of gas fire extinguishing system

The basic principles for the selection of gas fire extinguishing system are mainly considered from three aspects: environmental factors, toxicity and fire extinguishing efficiency. In terms of environment, the selection of gas fire extinguishing agents should be based on the principle of not depleting the atmospheric ozone layer. First, the fire extinguishing agent with ODP value (ozone depletion potential value is the relative value of measuring the destructive effect of gas fire extinguishing agents on the atmospheric ozone layer) is selected as zero. In terms of toxicity, the selection of gas fire extinguishing agent shall minimize the toxicity to human body. The places where the gas fire extinguishing system is applicable are generally places where people are often active, so it is very important to select low toxic fire extinguishing agents. The harm of gas fire extinguishing agent to people is mainly the toxicity of the fire extinguishing agent itself and the toxicity of the thermal decomposition products of the fire extinguishing agent at the fire site temperature. In terms of fire extinguishing efficiency, fire extinguishing agents with appropriate efficiency should be selected. The level of fire extinguishing efficiency is an important factor in the selection of fire extinguishing agents. The principle of gas fire extinguishing agent is to use chemical catalysis and high active free radicals in inerting flame to extinguish fire, such as heptafluoropropane fire extinguishing agent; There are also fire extinguishing through physical action (suffocation), such as carbon dioxide fire extinguishing agent and mixed gas fire extinguishing agent. When chemical fire extinguishing plays a leading role, the fire extinguishing agent is called chemical fire extinguishing agent, which has high fire extinguishing efficiency and low physical fire extinguishing efficiency.