METHOD FOR PREVENTING CHOKING OF UREA INJECTIION NOZZLE ON SCR SYSTEM

摘要

The present invention relates to a method for preventing the clogging of a urea injection nozzle in a selective catalytic reduction (SCR) system. According to an embodiment of the present invention, the method for preventing the clogging of a urea injection nozzle in an SCR system comprises: a vacuum step which generates negative pressure inside a supply module in order to collect urea; and a pressure equalization step which restores the pressure inside the supply module through pressure equalization when stopping the generation of negative pressure inside the supply module. The pressure equalization step controls the forced injection of urea based on pressure after a set time (t) upon completion of the entry into the pressure equalization step.