Maintenance-free submerged automatic fire extinguishing device for narrow electrical cabinet

The invention discloses a maintenance-free submerged automatic fire extinguishing device for a narrow electrical cabinet. The maintenance-free submerged automatic fire extinguishing device comprises a box shell and a locking unit, a box door is hinged to an opening in the right side face of the box shell through a hinge, a steel cylinder is installed in a containing groove formed in the bottom face in the box shell, an air outlet pipe is arranged at an air outlet in the upper end of the steel cylinder, an electromagnetic valve is connected into the air outlet pipe in series, a frame plate is arranged at the upper end in the box shell, a connecting pipe is arranged in a through hole in the left end of the frame plate, and a hose is arranged at the bottom end of the connecting pipe; according to the maintenance-free submerged automatic fire extinguishing device for the narrow electrical cabinet, submerged automatic fire extinguishing work can be achieved, manual operation of personnel is not needed, and the ste