AN UREA BACKFLOW PREVENTION APPARATUS OF SCR AND A CONTROL METHOD THEREOF

摘要

The present invention relates to a urea backflow prevention apparatus of a selective catalytic reduction (SCR) system, and a control method thereof. According to an embodiment of the present invention, the urea backflow prevention apparatus of the SCR in an SCR system injecting a urea aqueous solution to an exhaust pipe, comprises: a urea tank (10) to store the urea aqueous solution; a nozzle (20) to inject the urea aqueous solution to the exhaust pipe by being installed in the exhaust pipe; a supply pump (30) to pressurize the urea aqueous solution to inject the urea aqueous solution to the exhaust pipe from the nozzle (20); a suction line (40) to supply the urea aqueous solution stored in the urea tank (10) to the supply pump (30) by connecting the urea tank (10) and the supply pump (30); a pressure line (50) to deliver the urea aqueous solution pressurized by the supply pump (30) to the nozzle (20) by connecting the supply pump (30) and the nozzle (20); and a return line (60) to return the urea aqueous solution not injected from the nozzle (20) to the urea tank (10) by connecting the supply pump (30) and the urea tank (10). According to the present invention, the urea backflow prevention apparatus prevents the supply pump from being damaged by icing of the backflowing urea aqueous solution by preventing the backflow of the urea aqueous solution.