System for denitrifying exhaust gas capable of preventing blockages in a urea water inflow path and an injection nozzle, and device for supplying urea water capable of preventing the coagulation of urea water

摘要

A system for denitrifying exhaust gas, including a urea water injection unit for supplying urea water and air to a reaction chamber, wherein the urea water injection unit includes: an air supply unit for supplying external air to an injector through an air supply line; a urea water supply unit for supplying urea water to the injector through a urea water supply line; a water supply unit for supplying water to the injector through a water supply line connected to one side of the urea water supply line; a flow control valve for selectively supplying water or urea water to the injector through the urea water supply line; and the injector respectively connected to the air supply unit and the urea water supply unit to selectively discharge air, urea water or water to the reaction chamber through an injection nozzle.