Abstract: A selective catalytic reduction system includes a selective catalytic reduction device on an exhaust pipe of an engine, a urea solution tank that stores a urea solution, a float-type urea solution level sensor in the urea solution tank, a dosing valve on the exhaust pipe upstream of the selective catalytic reduction device, a urea solution injection control section that controls an amount of urea solution to be injected through the dosing valve in accordance with an amount of NOx discharged from the engine, an inclination sensor that detects an inclination angle of the urea solution tank relative to horizontal, and an inclination angle correcting section that corrects a liquid level of the urea solution, the liquid level being detected by a detection unit from the position of a float, with the inclination angle detected by the inclination sensor.

Abstract: A clogging detection device includes a urea water sensor which detects temperature in a urea water tank, a pressure sensor which detects pressure in a urea water feed line, an exhaust gas temperature sensor disposed in an exhaust pipe upstream of a selective catalytic reduction device, and a determination unit. When a key switch is turned on, the determination unit performs a startup control to drive a supply pump and increase the pressure in a pipe segment extending to a dosing value. If a detection value of the exhaust gas temperature sensor is no greater than a predetermined temperature, and a detection value of the urea water sensor is no smaller than a freezing temperature, then the determination unit performs emptying control for returning the urea water from the pipe segment to the urea water tank to detect clogging of the pipe segment from the detection value of the pressure sensor.

Abstract: A selective catalytic reduction system includes a selective catalytic reduction device on an exhaust pipe of an engine, a urea solution tank that stores a urea solution, a float-type urea solution level sensor in the urea solution tank, a dosing valve on the exhaust pipe upstream of the selective catalytic reduction device, a urea solution injection control section that controls an amount of urea solution to be injected through the dosing valve in accordance with an amount of NOx discharged from the engine, an inclination sensor that detects an inclination angle of the urea solution tank relative to horizontal, and an inclination angle correcting section that corrects a liquid level of the urea solution, the liquid level being detected by a detection unit from the position of a float, with the inclination angle detected by the inclination sensor.

Abstract: A clogging detection device includes a urea water sensor which detects temperature in a urea water tank, a pressure sensor which detects pressure in a urea water feed line, an exhaust gas temperature sensor disposed in an exhaust pipe upstream of a selective catalytic reduction device, and a determination unit. When a key switch is turned on, the determination unit performs a startup control to drive a supply pump and increase the pressure in a pipe segment extending to a dosing value. If a detection value of the exhaust gas temperature sensor is no greater than a predetermined temperature, and a detection value of the urea water sensor is no smaller than a freezing temperature, then the determination unit performs emptying control for returning the urea water from the pipe segment to the urea water tank to detect clogging of the pipe segment from the detection value of the pressure sensor.

Abstract: A urea water consumption diagnostic device includes a sensor which detects a level of urea water in a urea water tank, a calculation unit which calculates a cumulative consumed amount based on a detection value entered from the sensor and calculating a replenishment amount based on a change in the detected level of the urea water after a replenishment of the urea water, and a unit which, when a cumulative instructed injection amount of the urea water injected from a dosing valve has become greater than or equal to a determination amount, determines whether or not there is clogging of the urea water by comparing the cumulative consumed amount to the cumulative instructed injection amount. The calculation unit subtracts a level from the changed level of the urea water detected by the sensor upon replenishment to the urea water tank, and stores the resulting level as the replenishment amount.

Abstract: A turbo compound engine is provided with a rotor which is connected to the engine's output shaft so as to deliver working medium, such as intake air or exhaust gas or a mixture of the two, and a bypass line that bypasses the rotor, so that it not only utilizes the compression work and delivery work the rotor performs for a part of the braking force in the event of engine braking, but also attains a rapid and smooth increase in engine power output by allowing the working medium to bypass the rotor for a while when the engine operation mode is shifted from rotor-assisted engine brake mode to rotor-assisted engine drive mode for acceleration.