Forward and reverse washing automatic switching control system for plate heat exchanger of nuclear power plant

The invention belongs to the technical field of nuclear power, and particularly relates to a positive and negative washing automatic switching control system for a nuclear power plant plate heat exchanger. In the invention, the pressure difference high automatic backwashing mode can perform backwashing in time when the plate heat exchanger runs for a period of time and generates sediment deposition to cause pressure difference rise, thereby reducing the sediment deposition of the plate heat exchanger, reducing the pressure difference and improving the heat exchange efficiency; according to the timing backwashing mode, fixed time can be set to automatically trigger a backwashing command, and the lower pressure difference level of the plate heat exchanger is always kept, so that the automatic switching control device of the remote operation valve is realized, the quick response is realized, the working efficiency is greatly improved, the manpower and material resources are greatly saved, and the industrial safe