The invention relates to the field of fire rescue, in particular to a
compressed air foam fire extinguishing
system and a control method. When fire extinguishing is needed, firstly, a
fire pump, a foam liquid pump and an
air compressor are controlled to be started, and an
electromagnetic valve and a partition selection valve are controlled to be opened; after the
electromagnetic valve is controlled to be opened, whether the
electromagnetic valve is normally opened or not is firstly determined, after it is determined that the electromagnetic valve is normally opened, the compressed
gas cylinder can rapidly supply gas to the gas-liquid proportional mixer before the
air compressor is started, the effect of rapidly generating qualified foam is achieved, and the
gas supply response speed is high; whether the
air compressor is started successfully or not is checked within the set time after the air compressor is controlled to be started and the electromagnetic valve is determined to be opened successfully, after the air compressor is determined to be started successfully, the electromagnetic valve is closed to
cut off air supply of the
compressed air cylinder, the air compressor supplies air continuously, and the continuous foam supply fire extinguishing time of the
system is prolonged. According to the trial spraying method, regular trial spraying can be carried out on the premise that gas of a compressed
gas cylinder is not used, and the maintenance
workload is small.