Fire and explosion prevention measures for oil sto

Fire prevention and explosion-proof measures for oil storage in underground tunnels - electrical explosion-proof design (3)

1 explosion-proof measures for electrical equipment

(1) all power supply systems, lighting equipment, communication equipment, etc. should be kept dry and well insulated, and the tunnel wall should not be soaked and dripping on it, causing short circuit, heating, burning or poor contact, and fire jumping

(2) explosion proof electrical equipment should be selected. The lighting fixtures, operation column buttons, sockets, maintenance switches, junction boxes and field instruments in the reservoir area shall be explosion-proof; The cable led to the junction box (port) of electrical equipment passes through explosion-proof flexible connecting pipe. Cables should be laid overhead and should be flame retardant; The cable goes into the valve room and the imported sensor has high accuracy. The wall hole of the oil pump room should be filled and sealed; The tip of the gold diamond scriber of the electrical equipment contacting the shell of the test piece shall be reliably grounded, and the grounding trunk line shall be connected with the grounding body at least at two places in different directions in the explosion hazard area

2 lightning protection measures

(1) the cavern oil tank is set in the Manually Excavated tank room. The thickness of the natural protective layer on the top of the tank room is required to be 30m thick, so its natural protection ability is strong, and there is no lightning protection requirement for the tank body. However, the metal breathing tube and the metal ventilation tube exposed outside the tunnel should be equipped with independent lightning rod protection, and its protection range should be more than 2m higher than the pipe orifice. The horizontal position of the independent lightning rod from the orifice should not be less than 3m, and the tip of the lightning rod should be 4m higher than the top of the oil and gas pipe

(2) when the metal pipeline entering the tunnel is not buried outside the tunnel or the buried length is less than 50m, it should be grounded twice outside the tunnel. The spacing of grounding points should not be greater than 100m, and the impulse grounding resistance should not be greater than 20 Ω. In this way, the high potential generated by lightning or lightning induction on the ground and pipeline trench can be greatly reduced before being introduced into the tunnel, so as to avoid lightning accidents in the tunnel

(3) in order to prevent accidents caused by high potential introduced into the cavern along the low-voltage overhead line during lightning strike, it is required that the power, lighting and communication lines should be buried in the cavern with armored cables; If the overhead line is converted into the cable buried approach tunnel, the distance from the hole to the conversion shall not be less than 50m; 2. Valve arrester shall be installed at the connection between cable and after-sales service overhead line. Arrester, cable sheath and insulator iron foot shall be electrically connected and grounded, and its impulse grounding resistance shall not be greater than 10 Ω. Metal accessories such as flame arrester, breather valve and oil measuring hole must be kept in equipotential connection

3 anti static measures

(1) the flanges of the ventilation pipeline should be connected with conductors, and the whole air duct should be grounded to eliminate the static electricity generated by the flow of air in the pipeline and prevent the combustion and explosion accidents caused by static sparks

(2) all metal parts of the pipeline system in and out of the storage area or facilities, including the metal coating of the sheath, pipes, pumps and other parts must be grounded; There should be an anti-static grounding at both ends of the pipeline and every 200m~300m, as well as at branches and corners; The grounding point should be set at the pipe pier, and its impact grounding resistance should not be greater than 30 Ω

(3) electrostatic conductive hand grips should be set at the entrance of the oil storage cavern, the entrance of the oil storage tank room, the door of the pump room and the oil filling room; The handle body shall be connected with the grounding body with a lead; Fire hood and grounding brush shall be equipped in the automobile loading and unloading area; Provide operators with anti-static clothing, shoes and hats, explosion-proof flashlight, etc

(4) a small amount of oil soluble antistatic additives can be added to the hole stored petroleum products to make its conductivity reach more than 50ps/M; The widely tested single-1 solution in the storage tank to meet the requirements of global plastic processing and packaging material manufacturers. The liquid antioxidant wall should use anti-static anti-corrosion coating, and the coating body resistance should be less than 108 Ω· M

(5) measures should be taken to prevent the mixing of air, water, dust and other substances when transporting oil products through pipelines

sun Mingwei, Wang Xin, Zhao Yinong