火灾是燃料和空气中的氧气发生化学反应的过程。维持燃烧的前提条件是:燃料(可以是固态、液态或是气态的);氧气;火源;和不间断的链式反应同时存在。火灾的规模是由其放热率来划分的,以瓦特来度量。小型闷火灾(无火焰)的放热率为100KW,能够利用手提式灭火器来扑灭的有焰燃烧的放 Fire is the chemical reaction of fuel with oxygen in the air. Prerequisites for maintaining combustion are: fuel (which can be solid, liquid or gaseous); oxygen; a source of ignition; and uninterrupted chain reactions coexist. The size of the fire is divided by its heat release rate, measured in watts. Small stuffy fire (no flame) heat release rate of 100KW, can use portable fire extinguishers to put out the flaming combustion