Electric-pulse fracturing device and method for hard roof of coal mine based on self-sealing water bag

An electric-pulse fracturing device for hard roof of coal mine, comprising:

• a power switch,
• a charging power supply,
• a current limiting protection resistor,
• an energy storage capacitor and a high-voltage electric pulse switch connected in sequence, wherein the energy storage capacitor is connected with an end of a gas gap switch;
• wherein an other end of the gas gap switch is connected with assembled self-sealing water bag high-voltage electric pulse electrode structures through a high-voltage cable, and the assembled self-sealing water bag high-voltage electric pulse electrode structures are fixed through an assembly rod and connected with the high-voltage cable;
• wherein each of the assembled self-sealing water bag high-voltage electric pulse electrode structures comprises a self-sealing water bag and an electrode structure capable of focusing shock wave energy, a plurality of water-filled self-sealing water bags and the plurality of assembled self-sealing water bag high-voltage electric pulse electrode structures are alternately fixed on the assembly rod;
• wherein the assembly rod has a main body of a hollow high-strength steel pipe;
• the high-voltage cable connecting a discharge electrode and a grounding electrode passes through the assembly rod to protect the high-voltage cable from being damaged during electric pulse discharge;
• a top end of the assembly rod is provided with a self-supporting fixing bracket for extending into a bottom of a fracturing hole;
• and
• the assembled self-sealing water bag high-voltage electric pulse electrode structures are fixed at an appropriate position on the assembly rod, ensuring that the assembled self-sealing water bag high-voltage electric pulse electrode structures correspond to an optimal electrode depth in a fracturing design when the assembly rod extends into the fracturing hole.