A diagnostic device includes: a DOC for oxidizing hydrocarbon (HC) contained in an exhaust gas; a first sensor for detecting an exhaust gas temperature at a DOC inlet; a second sensor for detecting an exhaust gas temperature at a DOC outlet; a third sensor for detecting ambient temperature; an HC heat generation rate calculation unit which calculates, based on detection values of the first and second sensors, a difference in an exhaust gas heat quantity between upstream and downstream sides of the DOC, calculates, based on the detection values of the three sensors, a heat loss quantity released to outside air from the DOC, and adds the heat loss quantity and the exhaust gas heat quantity difference to calculate a heat generation quantity of HC in the DOC; and a DOC deterioration determination unit which determines, based on the calculated HC heat generation quantity, deterioration of the DOC.

A diagnostic device for an exhaust gas purification system that has a diesel oxidation catalyst (DOC), a diesel particulate filter, and an exhaust pipe injection device. The device includes a sensor for detecting a temperature of the DOC, a first calculation unit for converting an integration time of the detected temperature between regeneration intervals into a thermal history time with respect to a predetermined set temperature, and calculating a degree of degradation of the DOC based on this thermal history time, a second calculation unit for calculating a quantity of heat generated in the DOC based on the detected temperature during a forced regeneration execution period, and calculating another degree of degradation of the DOC based on the quantity of heat generated; and a diagnosis unit for diagnosing a degradation state of the DOC based on the degrees of degradation entered from the first and second calculation units.

A method for adjusting the temperature of an exhaust gas aftertreatment device is disclosed. A first characteristic temperature value for an oxidative carbon monoxide conversion and a second characteristic temperature value for an oxidative hydrocarbon conversion are assigned to an oxidation catalytic converter, and a third characteristic temperature value for a reductive NOx conversion is assigned to an SCR catalytic converter. Different respective values for injection parameters of injection processes for fuel injections into combustion chambers of the internal combustion engine and/or the heating output of an electric heating element are set upon reaching the first and the second characteristic temperature values for the temperature of the oxidation catalytic converter and upon reaching the third characteristic temperature value for the temperature of the SCR catalytic converter.

A method of regenerating a selective catalytic reduction catalyst on a diesel particulate filter (SDPF) includes predicting a reducing agent amount oxidized in the SDPF during regeneration of the SDPF if the regeneration of the SDPF is necessary; calculating a quantity of heat generated from the reducing agent amount oxidized in the SDPF; calculating a temperature change from the generated quantity of heat; calculating a target temperature when regenerating the SDPF; and performing the regeneration according to the target temperature.

An exhaust purifying device (10) includes a throttle valve (20), a DOC device (30), an SCR device (50), a fuel injector (7), an inlet temperature sensor (31), an outlet temperature sensor (45), and a controller (8). The controller (8) includes a heatup-control execution control unit (82) configured to perform a regeneration treatment for removing a urea deposit when a predetermined heatup control execution condition is met, and a condition judgment unit (83) configured to judge whether or not the first condition is met during the regeneration treatment by the heatup control.

An exhaust gas purification apparatus of an internal combustion engine includes: a reducing agent passage that connects a tank and an injection valve; a heater that heats up a hydrolysis catalyst that is provided in the reducing agent passage; and a controller comprising at least one processor configured to control a pump so that a reducing agent located further toward a side of the injection valve than the hydrolysis catalyst flows toward a side of the hydrolysis catalyst after completion of injection of a reducing agent in a state where the hydrolysis catalyst is at a temperature lower than the hydrolysis temperature and before start of injection of a reducing agent in a state where the hydrolysis catalyst is at a temperature equal to or higher than the hydrolysis temperature.

A method is disclosed for regulating an exhaust after-treatment (AT) system for a diesel engine. The method includes detecting the engine's cold start when the engine's exhaust gas flow directed into the AT system is at a temperature below a threshold value. The method also includes determining flow-rates of the engine's exhaust gas and its fuel supply. The method additionally includes determining a magnitude of exhaust gas energy using the determined exhaust gas flow-rates and the fuel supply over an elapsed time following the cold start. The method also includes integrating a detected temperature of the exhaust gas over the elapsed time and comparing the determined magnitude of exhaust gas energy with the integrated temperature. Furthermore, the method includes regulating operation of the AT system using the determined exhaust gas temperature when the determined magnitude of exhaust gas energy is within a predetermined value of the integrated exhaust gas temperature.

An internal combustion engine, wherein a chemical thermal storage device is provided with a first heater including a first element generating heat when chemically adsorbing a reaction medium supplied from a storage part through a first connection pipe and desorbing the reaction medium if heated by the heat of exhaust in a state chemically adsorbing the reaction medium and a second heater including a second element generating heat when chemically adsorbing a reaction medium supplied from a storage part through a second connection pipe and desorbing the reaction medium if heated by the heat of exhaust in a state chemically adsorbing the reaction medium and wherein the control device controls the opening degrees of the first valve and the second valve so that the reaction medium supplied to the second heater is preferentially recovered at the storage part.

A method for heating an exhaust system downstream from an internal combustion engine using an electrical heating device. The method includes an ascertainment of a current temperature in the exhaust system, an ascertainment of a current temperature of the electrical heating device and a fluid mass flow flowing through the electrical heating device, an ascertainment of a heating requirement based on the ascertained current temperature and a target temperature, a calculation of a required amount of heat depending on the heating requirement and an amount of energy required to heat up the electrical heating device, taking into account a heat input into the fluid mass flow to be expected at the ascertained current temperature of the electrical heating device, and a control of the electrical heating device to generate the calculated amount of heat. A computing unit and a computer program are also described.

Methods and systems are provided for model-based determination of a temperature distribution of an exhaust aftertreatment system of a vehicle. A power demand from a first component of the aftertreatment system is measure, a heat transfer into the first component of the aftertreatment system based on power demand of the first component and a configurable emissivity value of the exhaust gas is determined, and the temperature of the first component based on the calculated heat transfer is calculated.