A flow manifold system for injecting a first gas into a second gas, such as, for example, a system for injecting ammonia gas into the exhaust gas of an internal combustion engine. The first gas may be supplied to the system by one or more cartridges. The system may also include a control valve that is configured to control the delivery of the first gas to the least one critical flow orifice. The critical flow orifice is configured to allow for a relatively constant volumetric flow of the first gas through the critical flow orifice when the first gas attains a critical flow. Such critical flow may allow for an accurate estimation of the flow of the first gas through the critical orifice, and subsequently to the second gas, without the use of a flow sensor.

An internal combustion engine arrangement includes an internal combustion engine, a catalytic converter, and a controller. The controller is configured to determine a maximum H.sub.2 production capacity of the catalytic converter. The catalytic converter is arranged downstream of the internal combustion engine. The controller is configured and adapted to determine the maximum H.sub.2 production capacity of the catalytic converter based on a first function that correlates an H.sub.2 production of the internal combustion engine with first internal combustion engine parameters.

An additive amount of a reducing agent to a selective reduction-type NOx catalyst is optimized. An ammonia adsorption amount of the selective reduction-type NOx catalyst is estimated based on one or a plurality of prescribed parameters related to the ammonia adsorption amount and a specific ammonia adsorption amount that is an estimated value of the ammonia adsorption amount specified by at least one of a maximum value and a minimum value of an estimated value of the ammonia adsorption amount is estimated based on an error in the prescribed parameter, and when the specific ammonia adsorption amount is outside a target range of the ammonia adsorption amount, addition of an ammonia precursor or ammonia using an adding valve is controlled such that the specific ammonia adsorption amount returns to the target range.

An exhaust gas purification device includes a diesel particulate filter (DPF) for capturing particulate matter (PM) in an exhaust gas, a selective catalytic reduction (SCR) device for reducing NOx in the exhaust gas, detecting units for detecting the DPF electrostatic capacity, an estimating unit for estimating the inside temperature of the DPF based on the electrostatic capacity, and a controlling unit for executing forced DPF regeneration. A lower limit temperature is defined as a temperature to trigger PM combustion, and an upper limit temperature is defined as a temperature to avoid filter erosion. The controlling unit executes the forced regeneration with an amount of fuel supplied for causing the inside temperature to reach the lower limit temperature, when the inside temperature is at or above the SCR activation temperature, and executes the forced regeneration with another amount of fuel supplied for causing the inside temperature to reach the upper limit temperature, when the inside temperature is below the SCR activation temperature.

A degradation diagnosis device includes a downstream air-fuel ratio sensor and a control device. The control device is configured to perform a rich process and a lean process alternately and repeatedly in a degradation diagnosis process for diagnosing degradation of the exhaust gas control catalyst. The control device is configured to, in the degradation diagnosis process, determine that the exhaust gas control catalyst has been degraded when the lean process is executed and the frequency with which an output air-fuel ratio of the downstream air-fuel ratio sensor is equal to the lean air-fuel ratio is equal to or more than a predetermined frequency.

A method for diagnosing a diesel oxidation catalyst fault includes: obtaining an standard molar enthalpy of formation-revolution speed-load table; obtaining a revolution speed, a load, a temperature difference of front and rear exhaust pipes, and a casing temperature, obtaining an standard molar enthalpy of formation corresponding to the revolution speed and the load from the standard molar enthalpy of formation-revolution speed-load table, and calculating an actual formation enthalpy corresponding to the temperature difference of front and rear exhaust pipes and the casing temperature from the temperature difference of front and rear exhaust pipes and the casing temperature; calculating a standard reaction enthalpy from the standard molar enthalpy of formation and standard conversion efficiency; and diagnosing a diesel oxidation catalyst fault by comparing the actual formation enthalpy with the standard reaction enthalpy. The method is capable of realizing online fault diagnosis on a diesel oxidation catalyst without the disassembly of the diesel oxidation catalyst.

A method is provided for controlling an internal combustion engine as a function of an expected value of a temperature of a component of an exhaust gas system, route data of an expectable driving route being assigned values of exhaust gas temperatures. The method is characterized in that the route data are assigned engine operating data which are expectable when passing through the expectable driving route and in that a first exhaust gas temperature expected value is computed and assigned to a route section, in that the route is subdivided into characterizable route sections, in that each of these route sections is assigned a predetermined second exhaust gas temperature expected value which is based on at least one exhaust gas temperature value measured at an earlier point in time, and in that the expected value of the temperature of the component is formed on the basis of linking the first exhaust gas temperature expected value to the second exhaust gas temperature expected value.

A system and method that forwards information concerning the condition of the particulate filter (14) in each fleet vehicle to a remote station (56). This information is sorted (114) and displayed (62) to a human operator, who then makes a decision regarding particulate filter maintenance, on a fleet wide basis (116). The human operator may select a set of vehicles to undergo filter regeneration during a particular time slot, at a facility with a limited capacity to perform filter regeneration during any particular time slot. Typically, this will be overnight, for example for a metropolitan bus service that is busy during the day but has greatly reduced or nonexistent service at nighttime.

A method is provided for managing the light-off of a 3-way catalytic converter that is located in an exhaust line of a petrol engine having a plurality of cylinders with each cylinder having at least one exhaust valve. The method includes calculating a value of enthalpy of exhaust gases to make it possible to determine a quantity of heat supplied to the three-way catalyst, determining a threshold enthalpy value signaling the light-off of the catalyst, and stopping of activation of the three-way catalyst upon determining the value of the enthalpy that was calculated has reached the threshold enthalpy value.

An after treatment method is disclosed. The after treatment method may include: operating an engine at a lean air/fuel ratio; calculating an amount of NH.sub.3 stored in an SCR catalyst; calculating an amount of NOx which will flow into the SCR catalyst; determining whether conversion to a rich air/fuel ratio is desired; calculating, when the conversion to the rich air/fuel ratio is desired, a rich duration for which the rich air/fuel ratio is maintained and a target air/fuel ratio; and operating the engine at the target air/fuel ratio for the rich duration.