An exhaust purification system of an internal combustion engine includes a catalyst arranged in an exhaust passage of the internal combustion engine, a fuel supply device supplying fuel to the catalyst through the exhaust passage, and a control device configured to control the supply of fuel by the fuel supply device. The control device is configured to calculate a concentration in exhaust gas of fuel supplied to the exhaust passage by the fuel supply device and a saturation vapor pressure concentration of the fuel and supply fuel from the fuel supply device to the catalyst only when the concentration in the exhaust gas is higher than the saturation vapor pressure concentration.

A reduction in measurement accuracy of a concentration sensor is minimized. An exhaust gas purifying device of a work machine includes a reduction catalyst that is placed in an exhaust flow passage of an exhaust gas of an engine and uses a reducing agent to reduce and purify nitrogen oxides in the exhaust gas, and a reducing agent injector to inject the reducing agent into the exhaust flow passage. The exhaust gas purifying device of a work machine includes: a storage unit that stores the reducing agent; a concentration sensor that has a sensing part placed within the storage unit to detect a concentration of the reducing agent; an air-bubble removal device that injects the reducing agent toward the sensing part; and a reducing agent pump that supplies the reducing agent in the storage unit to the air-bubble removal device.

An exhaust system provided with exhaust gas after-treatment for a combustion engine comprising an exhaust pipe and a pumping device, which is buried inside the tank, from which it draws so as to feed a water solution of urea under pressure to an electromagnetic injector; the tank is supplied with urea powder and water, which are mixed on the inside so as to obtain a water solution of urea with a variable concentration; and a water supply circuit to supply water to the tank, which is provided with a first pipe, which draws the water from a basin and is regulated by a first valve, which allows water to be introduced into the tank, if necessary, or to be drained to the surrounding environment when the water quantity already contained in the tank is sufficient.

An aftertreatment system includes an exhaust reductant tank configured to store an exhaust reductant. A filter is fluidically coupled to the exhaust reductant tank. The aftertreatment system includes a hydrocarbon detection device configured to indicate the presence of a hydrocarbon in the exhaust reductant. A catalyst is included in the system and configured to treat the exhaust reductant flowing through the system. The hydrocarbon detection device can include a hydrophobic paper, and can be disposed in the filter.

A level sensor assembly (10) for measuring physical properties indicative of a quality of a urea solution (AdBlue/DEF), where at least a portion of said level sensor assembly (10) is inserted in a tank (50), said level sensor assembly (10) comprises a header unit (12) mounted in an aperture of the tank (50); heating tubes (20) inserted in the tank for heating/thawing the urea solution in the tank (50) and one or more tubes (22) for suction of urea solution from the tank (50), said tubes (20,22) being connected to the header unit (12); and a level sensor (24,26) for measuring level of urea solution in the tank (50). Further, a detachable UQS sensor (30) is installed in the header unit (12), said UQS sensor (30) being at least partly submerged in a liquid pool (32) of urea solution in the header unit (12), and the liquid pool (32) in the header unit (12) comprises a compressible and/or expanding bottom (34).

The present invention relates to a method for restricting work produced by combustion in a combustion chamber, wherein an aftertreatment system is arranged for reduction of at least one substance resulting from the combustion, wherein the work produced by the combustion is restricted when there is a malfunction regarding reduction of the at least one substance. The method includes: performing a first evaluation regarding the reduction of the at least one substance, when the first evaluation indicates a malfunction, performing a second evaluation regarding the reduction of the at least one substance, the second evaluation being different from the first evaluation, and restricting work produced by the combustion only when a malfunction regarding reduction of the at least one substance is indicated also by the second evaluation.

A urea concentration sensor reflector system includes a urea concentration sensor reflector assembly including a reflector having an upwardly convex dome shape integrally connected to and supported by multiple legs. The reflector includes a concave-shaped inner surface. The multiple legs are connected to and support the urea concentration sensor reflector assembly to an upward directed surface of a bottom tank wall of a urea storage tank. A sound wave generator and receiver is fixed to the bottom tank wall directly below and centrally aligned with the reflector. The sound wave generator and receiver generates ultrasonic sound waves directed upwardly toward the reflector. A concentration of a liquid urea in the urea storage tank is determined based on a time for the ultrasonic sound waves to travel to the reflector and return as echo signals to the sound wave generator and receiver, and a temperature of the liquid urea.

A virtual diesel exhaust fluid (DEF) quality monitor repeatedly performs an intrusive test for disclosing use of adulterated DEF by injecting a controlled quantity of DEF into a diesel engine exhaust aftertreatment system upstream of an SCR catalyst while the engine operates and then processing certain data obtained from the test.

A urea water supply device supplying urea water to purify exhaust gas from an electric power generating engine. The urea water supply device includes: a urea water injector; a urea water flow route in which urea water flows; a clean water supply route in which clean water flows; and a urea water amount adjustment valve and a urea water flow meter provided in the urea water flow route. The clean water supply route merges with the urea water flow route on the downstream side of the urea water amount adjustment valve and the urea water flow meter.

A sensor device for a container of a liquid substance comprises a body with a housing portion having a closing structure, the body having an inner surface and an outer surface. The housing portion is pre-arranged for assembly on the container, in such a way that a portion of the outer surface of the body faces the inside of the container to be in contact with the liquid substance, and the inner surface of the body is isolated from the inside of the container. Associated to the body is a first arrangement for detection of the level of the substance. Associated to the body of the device is a second arrangement for detection of a characteristic of the liquid substance, which comprises an emitter and a receiver of a given optical radiation. A first portion of the body of the device is made of a material designed for propagation of the given optical radiation, the emitter and the receiver being optically coupled to the inner surface of the body at the first portion. The first portion of the body of the device is shaped to contribute to propagation of the given optical radiation from the emitter to the receiver, in such a way that the given optical radiation is propagated through the first portion of the body of the device towards the receiver, at an angle and/or with an intensity that are/is variable as a function of the characteristic of the liquid substance.