Abstract: This paper takes the No.1 cooling water plant in the new-built ethylene project of a petrochemical plant as an example, introduces the main process flow and seawater utilization mode of closed circulating cooling water system using seawater as the cooling medium in large-scale petrochemical plants, provides the calculation and automatic control process of pressure stabilizing and cooling water supply equipment, discusses the selection and operation principles of critical equipment such as circulating cooling water lift pump, ciruclating cooling water plate heat exchanger, seawater filter and dosing system, and summarizes the characteristics and advantages of closed circulating cooling water system using seawater as the cooling medium, providing references for the water saving, energy saving and cost saving of petrochemical plants in coastal areas.

Key words: closed circulating cooling water system, seawater utilization, petrochemical enterprise, water saving