Perfluoro is a new type of fire extinguishing agent with high boiling point and meets the requirement of far distance of fire extinguishing spray of valve hall

good insulation performance and no pollution. In this paper

the influence of the perfluoro droplets with a diameter of 719.0 μm and gaseous perfluoro on the discharge characteristics of the short rod-plate air gap is studied. Under a 4 cm rod-plate gap

when the flow rate is risen from 0.27 L/min to 1.94 L/min

the breakdown field strength of the perfluoro droplets-air two-phase mixture is increased from 11.85 kV/cm to 14.35 kV/cm (it is 1.69 times higher than the breakdown field strength of the air gap). When the concentration of gaseous perfluoro is increased from 0.44% to 10.25%

the breakdown field strength of perfluoro gas-air mixture is risen from 10.50 kV/cm to 18.68 kV/cm (it is 2.65 times higher than the breakdown field strength of the air gap). The discharge development is hindered by the electronegativity of perfluoro gas

the temperature drop due to vaporization of the perfluoro droplets and the charge of the perfluoro droplets and the the breakdown voltage of the gap is increased. The discharge development is promoted by the distorting electric field of the perfluoro droplets and the photoionization effect. However

the electronegativity of perfluoro gas and the charging of perfluoro droplets are the main reason for increasing the discharge voltage of the gap. The results can provide guidance for the application of perfluoro in preventing electrical fires.