Pressure relief device suitable for water supply system with backpressure technology

The utility model relates to a pressure relief device suitable for a water supply system with a backpressure technology, which comprises a water supply pipe connected between a volute water intake and a draft tube, an electric flow regulating valve is mounted on the water supply pipe, and the electric flow regulating valve is electrically connected with a control cabinet. A pressure transmitter is installed on the pipeline between the electric flow regulating valve and the volute water taking opening, a first pressure switch and a second pressure switch are installed on the pipeline between the pressure transmitter and the volute water taking opening, and the first pressure switch, the second pressure switch and the pressure transmitter are all electrically connected with the control cabinet. According to the device and the method, the stability and the reliability of a hydropower station unit technical water supply system, a main transformer technical water supply system and an air conditioner technical wate