Control method for concentration ratio of circulating cooling water and circulating cooling water system

The invention provides a circulating cooling water concentration ratio control method and a circulating cooling water system which comprises a cooling tower, a circulating water pool, a first circulating water pipeline, a second circulating water pipeline, a blow-off pipeline, a water supplementing pipeline and a condenser. The circulating water output end of the circulating water pool is connected with one end of the water side of the condenser through the first circulating water pipeline, the other end of the water side of the condenser is connected with the circulating water input end of the cooling tower through the second circulating water pipeline, and the second circulating water pipeline is provided with a pH sensor and a second conductivity meter. The pH sensor is close to the condenser, a first conductivity meter and a second control valve are sequentially arranged on the water supplementing pipeline, and a first control valve is arranged on the blow-off pipeline. By using the method disclosed by th