METHOD FOR CONTROLLING DESULFURIZATION IN EXHAUST GAS PURIFICATION SYSTEM, AND EXHAUST GAS PURIFICATION SYSTEM

摘要

This invention provides an exhaust gas purification system (1) comprising an NOx conversion catalyst device (11) with an NOx conversion catalyst supported thereon for the conversion of NOx in the exhaust gas. In the control of desulfurization, in order to accurately introduce a fuel in a necessary and sufficient amount for raising the temperature for allowing the NOx conversion catalyst device (11) to be brought to a desulfurization target temperature even during transient operation to maintain the state of the device at a temperature of the desulfurization target temperature or above, the amount of fuel (Wf) necessary for raising the first detection temperature (Tc1) as an indicator of the catalyst temperature in the NOx conversion catalyst device (11) to a desulfurization target temperature (Tsp) is set using the heat quantity computed from the first heat quantity (Q1) necessary for raising the temperature of the NOx conversion catalyst device (11) and the second heat quantity (Q2) necessary for raising the temperature of the exhaust gas.