Automatic backwashing system of plate heat exchanger

The invention relates to an automatic backwashing system for a plate heat exchanger. The automatic backwashing system comprises a PLC (Programmable Logic Controller); the temperature sensor and the pressure sensor are arranged on a cooling water inlet and outlet pipeline and a circulating water inlet and outlet pipeline of the plate heat exchanger, and the temperature sensor and the pressure sensor are respectively connected with the PLC; the backwashing pipeline comprises a chemical tank and a backwashing pump which are sequentially connected through a pipeline, two backwashing branches are further led out from an outlet of the backwashing pump to be respectively connected with the cooling water inlet and outlet pipeline and the circulating water inlet and outlet pipeline, and a cooling water side backwashing sub-loop and a circulating water side backwashing sub-loop are respectively formed; and the backwashing pump is also connected with the PLC controller. Compared with the prior art, a reasonable heat exc