Abstract: The present invention provides a technique for improving the cooling performance of a cooling tower in a circulating cooling water system having the cooling tower. The present invention provides a method for improving cooling performance of a cooling tower in a circulating cooling water system having the cooling tower, wherein cooling water used in the circulating cooling water system is cooling water to which an agent including a surfactant is added, and the cooling water satisfies (a) a dynamic contact angle of 55° or less and (b) a bubble bulkiness of 250 mL or less.

Abstract: A method for treating a cooling water system comprises adding, in a cooling water system having calcium hardness of 250 mg/L or less as CaCO3, a treatment agent containing a (meth)acrylic acid-based copolymer. The (meth)acrylic acid-based copolymer comprises a structural unit (a) derived from a (meth)acrylic acid-based monomer (A) represented by the following general formula (1) and a structural unit (b) derived from a specific (meth)allyl ether-based monomer (B) represented by the following general formula (2), a content of the structural unit (b) is 1 to 15 mol % relative to 100 mol % of structural units derived from all the monomers, a weight average molecular weight of the (meth)acrylic acid-based copolymer is 7,000 to 28,000, and at least one of the main chain terminals of the (meth)acrylic acid-based copolymer is a sulfonic acid group or a salt thereof.

Abstract: A method for treating a cooling water system includes adding a (meth)acrylic acid-based copolymer to a cooling water system having a part where the calcium hardness of the cooling water is 150 to 300 mg/L and the flow rate of the cooling water is 0.3 to 0.5 m/s, wherein the (meth)acrylic acid-based copolymer has a structural unit (a) derived from a specific (meth)acrylic acid-based monomer (A) and a structural unit (b) derived from a specific (meth)allyl ether-based monomer (B), the content of the structural unit (b) is 15% by mole to 20% by mole relative to 100% by mole of the structural units derived from all the monomers, the weight-average molecular weight of the (meth)acrylic acid-based copolymer is 10,000 to 30,000, and at least one of the main chain terminal groups of the (meth)acrylic acid-based copolymer is a sulfonic acid group or a salt thereof.

Abstract: A method for treating a cooling water system comprises adding, in a cooling water system having calcium hardness of 250 mg/L or less as CaCO3, a treatment agent containing a (meth)acrylic acid-based copolymer. The (meth)acrylic acid-based copolymer comprises a structural unit (a) derived from a (meth)acrylic acid-based monomer (A) represented by the following general formula (1) and a structural unit (b) derived from a specific (meth)allyl ether-based monomer (B) represented by the following general formula (2), a content of the structural unit (b) is 1 to 15 mol % relative to 100 mol % of structural units derived from all the monomers, a weight average molecular weight of the (meth)acrylic acid-based copolymer is 7,000 to 28,000, and at least one of the main chain terminals of the (meth)acrylic acid-based copolymer is a sulfonic acid group or a salt thereof.