Abstract: A catalyst activation method and a catalyst activation device are provided which can activate a NOx catalyst efficiently in an ensured fashion. A plurality of accessories are connected to an internal combustion engine, and a control mechanism is provided on each of the accessories for controlling a load to be exerted on the internal combustion engine by driving the corresponding accessory. Then, a temperature of a NOx catalyst is acquired, and when the acquired temperature of the NOx catalyst is lower than a catalyst activation temperature, in order to drive additionally a certain number of accessories in the plurality of accessories which correspond to the temperature difference, the controlling mechanism(s) which corresponds to the accessory(ies) to be driven additionally is controlled to drive the corresponding accessory(ies) so as to increase a load to be exerted on the internal combustion engine.

Abstract: A catalyst activation method and a catalyst activation device are provided which can activate a NOx catalyst efficiently in an ensured fashion. A plurality of accessories are connected to an internal combustion engine, and a control mechanism is provided on each of the accessories for controlling a load to be exerted on the internal combustion engine by driving the corresponding accessory. Then, a temperature of a NOx catalyst is acquired, and when the acquired temperature of the NOx catalyst is lower than a catalyst activation temperature, in order to drive additionally a certain number of accessories in the plurality of accessories which correspond to the temperature difference, the controlling mechanism(s) which corresponds to the accessory(ies) to be driven additionally is controlled to drive the corresponding accessory(ies) so as to increase a load to be exerted on the internal combustion engine.

Abstract: A selective catalytic reduction (SCR) system that can suppress thermal damage in operation of a dosing valve resulting from crystallization of urea solution and corrosion of the dosing valve to perform proper urea solution injection control, and includes an SCR device provided in an exhaust pipe of an engine; a dosing valve that injects urea solution at an upstream side of the SCR device; a minimum injection quantity setting unit that if temperature of the dosing valve is equal to or higher than a predetermined temperature, sets a minimum injection quantity according to the temperature of the dosing valve; and an urea solution injection control unit that if injected quantity of urea solution according to quantity of NOx emitted from the engine is smaller than the minimum injection quantity, controls the injected quantity of urea solution to be the minimum injection quantity.

Abstract: A selective catalytic reduction (SCR) system that can suppress thermal damage in operation of a dosing valve resulting from crystallization of urea solution and corrosion of the dosing valve to perform proper urea solution injection control, and includes an SCR device provided in an exhaust pipe of an engine; a dosing valve that injects urea solution at an upstream side of the SCR device; a minimum injection quantity setting unit that if temperature of the dosing valve is equal to or higher than a predetermined temperature, sets a minimum injection quantity according to the temperature of the dosing valve; and an urea solution injection control unit that if injected quantity of urea solution according to quantity of NOx emitted from the engine is smaller than the minimum injection quantity, controls the injected quantity of urea solution to be the minimum injection quantity.