Method for controlling injection of reducing agent in exhaust gas from a combustion engine

This invention involved a control restore agent spray into from internal combustion engine of with NOx exhaust flow in the of method, which produced has public known fuel of burning, and NOx in SCR exists Shi through selective catalytic restore, SCR, to restore, the method including established and exhaust flow, and catalyst upstream exhaust flow in the NOx of concentration, and SCR catalyst upstream of exhaust temperature, and SCR catalyst downstream of exhaust temperature about of signal and the and for catalyst characteristics of entered data about of signal. According to the signal through the use of reducing agents calculate the quantity and value of d (E*T)/dt calculated adjust the amount of reducing agent, which, e for exhaust gas flow, upstream of t is a catalyst for exhaust gas temperature, t is time.