Cathodic Protection System for Water Circulating Pipeline of Unit 8 Pow er Plant Desiign Calculation Sheets

1 General Introduction 1.1 Working conditions of the cathodic protection system The cathodic protection system will be installed on the water circulating pipeline and used to protect the pipeline from corrosion. The seawater is electrolyte inside of the pipeline, and the soil is outside of the pipeline. 1.2 Location conditions of the Unit 8 Power Plant This project aims to erect one set of 600MW power plant, which will not be extended. The site location of the power plant is in the west side of Jakarta, with a distance about110 km，and it is about 7 km from Merak. The site is with a geography location of southern latitude 5°45′ 14″and east longitude 106°2′32″This power plant has had seven set of power plants, with a capacity of 4×400MW+3×600MW. This project will utilized the seawater of Sanda Strait as the cooling water, supplied by a circulating water direct-flow system. The force main for circulating seawater will have a nominal diameter of DN3600, made of Q235A steel pipes. The（DN2200）pipes for connecting the force main to the outlet of the seawater circulating pump and the（DN2600）pipes for connecting the outlet of the water condenser to the siphon well, both are made of Q235B steel pipes, and the pipes connected to the closed cooling system, with a nominal diameter of DN900, are made from Q235B steel pipes. 1.3 Weather conditions 1) Atmosphere temperature Max. Temperature：35.5℃ Annual average temperature：27.0℃ Min. Temperature：22.7℃ 2) Rainfall Max. average annual rainfall：2055mm Many year average annual rainfall：1689mm Min. average annual rainfall：646mm Average month rainfall：504mm 3) Relative humidity： Relative humidity：62％～100％ Average annual relative humidity：83