When a rooftop photovoltaic power station fire occurs, the fire status should be judged by various means first, and the corresponding power supply should be disconnected to extinguish the fire, because it is safer to extinguish the fire after the power is cut off.
However, when the photovoltaic modules receive sunlight radiation during the day, each string will generate a DC voltage of several hundred volts, and the characteristics of the power supply cannot be cut off immediately, or if the power is saved after waiting for the power to be cut off, the timing will be delayed and the fire will spread. , expand the burning area. At this time, it is necessary to carry out electrified fire extinguishing while ensuring the safety of the fire-fighting personnel.
Before the live fire extinguishing, the DC output current of the photovoltaic power generation system should be reduced as much as possible. Consider using the fire blanket method to save the fire. Fire blankets, or fire quilts, fire quilts, fire blankets, fire blankets, fire retardant blankets, are fabrics that have been specially woven from materials such as fiberglass. They are a very soft fire-fighting implement. Its main function is mainly to block the sunlight, so that the photovoltaic module reduces or loses voltage, and covers the fire source and blocks the air to achieve the purpose of safe fire extinguishing.
The specific use of the fire blanket is: in the early stage of the fire, quickly take out the fire blanket, one person with both hands holding the two corners of the short side of the fire blanket, palms toward their chest. The other person holds the two corners of the other short side of the fire blanket with both hands, shakes the fire blanket, gently covers the fire blanket over the fire component, uses the output voltage to gradually decrease, and takes active fire extinguishing measures until the fire object is completely Extinguished.
When implementing it, you should also pay attention to:
1) Proper selection of fire extinguishing equipment
In general, it is not allowed to use foam fire extinguishing agent or water to extinguish fire-fighting equipment. Because the fire extinguishing agent (aqueous solution, jet water flow, etc.) of the foam fire extinguisher has certain conductivity and has an influence on the insulation of electrical equipment, it is not suitable for Have electrical equipment to extinguish the fire.
Generally used chemical dry powder fire extinguishing agent (ammonium phosphate dry powder fire extinguishing agent, ammonium phosphate dry powder fire extinguisher).
2) Fire equipment and live parts should maintain sufficient safety distance
If a fire extinguisher with non-conductive fire extinguishing agent such as chemical dry powder is used for fire extinguishing, the minimum distance between the body, the nozzle and the charged body is: the voltage is 10 kV and the following should not be less than 0.4 m, and the voltage is 35 kV or more. Should be less than 0.6m and so on.
When the high-voltage electrical equipment or line of the photovoltaic power station is grounded, the indoor rescue personnel shall not enter within 4m from the fault point; in the outdoor, the fire-fighting personnel shall not be within 8m from the fault point. When entering the above range, the insulated shoes must be worn. Above 10KV), wear insulated gloves when touching the equipment casing and frame.
3) If the fire in the photovoltaic power station is very hot and the firefighters are required to PV solar panel support the rescue, the firefighters should be reminded before the implementation of the firefighting: the rooftop photovoltaic equipment is still energized, and the DC side power supply cannot be cut off temporarily.
If a special case is to use a water gun to extinguish the fire, a spray gun should be used. When fighting a fire in an overhead line, the elevation angle between the human body and the charged body guide should not exceed 45°, and should stand outside the line to prevent the wire from falling off and touching the human body. In addition, if there is a live wire landing, a certain warning zone should be drawn to prevent the step voltage.