Abstract:
System to reduce the amount of NOx in exhaust gases of a vehicle. The system includes a storage space 1 containing an agent, a SCR catalytic converter 5, an injection module 6c to inject the agent upstream of the converter, a heat exchanger 2 containing a porous matrix, a shutter or injector 11 to control the flow rate of the agent to the exchanger, a valve 12 between the storage space and exchanger, to transfer thermal energy to gases during the starting period. The shutter or injector controls the flow of agent into the exchanger during the starting period to raise its temperature, and is closed when gases have reached a certain temperature. The valve regulates exchanger pressure during a period at operating temperature and conveys the agent to storage space when the exchanger pressure is higher than storage space pressure.
Abstract:
The invention relates to a system intended to reduce the amount of NOx in the exhaust gases of a motor vehicle. The system comprises a storage space (1) containing a reducing agent; an SCR (selective catalytic reduction) catalytic converter (5) for treating the exhaust gases laden with reducing agent, and an injection module (6c) designed to inject the reducing agent from the storage space (1) into the exhaust gases of the motor vehicle upstream of the SCR catalytic converter (5). The system further comprises: at least one heat exchanger (2) connected to the storage space (1) and containing a porous matrix intended to absorb the reducing agent originating from the storage space (1); a valve or an injector (11) downstream of the storage space (1) and upstream of the exchanger (2) and designed to control the addition of reducing agent to the exchanger (2), and a valve (12) positioned between the storage space (1) and the exchanger (2). This is designed to transfer thermal energy to the exhaust gases of the motor vehicle upstream of the SCR catalytic converter (5) during a first period known as the starting period following the starting of said vehicle. The valve or the injector (11) is designed to control the rate of flow of reducing agent into the exchanger (2) during said starting period so that the absorption of the reducing agent by the porous matrix of the exchanger (2) raises the temperature thereof. The valve or the injector (11) is also designed then to be closed during a period known as the period at operating temperature when the motor vehicle is running as soon as the exhaust gases have reached a certain temperature. The valve (12) is designed firstly to regulate the pressure inside the exchanger (2) during said period at operating temperature and secondly to convey the reducing agent contained in the exchanger (2) to the storage space (1) when the pressure inside the exchanger (2) is higher than the pressure inside the storage space (1).
Abstract:
A device intended to measure fouling and to locally heat an electrical insulating medium. At least one electrically resistive heating element (6, 8) is associated with a fouling detection unit. The fouling detection unit includes metallic elements (6, 10) in contact, at at least two points, with the insulating medium. The resistance variation between the two points is measured and is directly linked with the fouling of the medium.
Abstract:
The present invention relates to a method intended for desulfation of a nitric oxide trap (22) and regeneration of a particle filter (24) arranged in an exhaust line (20) for treating exhaust gas from an internal-combustion engine (10), notably a Diesel engine. According to the invention, the saturation rate of the trap and the clogging rate of the filter are evaluated and, as soon as one of the rates reaches a threshold value, the fuel/air ratio of the exhaust gas is increased without it reaching fuel/air ratio 1, then desulfation of trap (22) is performed in association with regeneration of particle filter (24).
Abstract:
Process and device for controlling the regeneration of an element filtering oxidable particles carried along by a gaseous stream, by periodic combustion of these particles, such as, for example, the carbon-containing particles carried along in the exhaust gas of a thermal engine (3), retained in an exhaust silencer (1). In an application to a thermal engine, the process comprises detecting the variation, measured by detectors (4, 5), in the oxygen content of the gaseous stream between at least a first point located upstream, in relation to the direction of flow, from filtering element (1) receiving the stream and at least a second point located downstream from the first one, resulting from a reaction of combustion of the particles accumulated in the filtering element, initiated by a management element (6) acting for example on the running of engine (3), which allows the latter to adjust with precision the stage of regeneration of the filtering element and therefore to limit overconsumption as far as possible.
Abstract:
The invention relates to a method for regenerating a particle filter (10) integrated into an exhaust line (12) of an internal combustion engine (34), wherein the exhaust gas flows into the filter via an inflow surface (16) and exit the filter via an outflow surface (18). According to the invention, the internal temperature of at least two regions of the filter (10) is monitored during regeneration of the filter; the oxygen content of the exhaust gas is reduced if at least one of the monitored temperatures rises above a critical temperature; the oxygen content of the exhaust gas is increased in order to continue regeneration if all of the monitored temperatures are below said critical temperature.
Abstract:
A process and device for local permeability evaluation and local regeneration of a particle filter consisting of several juxtaposed zones through which a flow of gas to be scrubbed is passed include the steps of and apparatus for measuring the temperature of the flow upstream from the filter, measuring the temperature in at least one of the zones forming the filter, evaluating the thermal inertia of at least one of the zones by relative measurement of the temperature or of the local resistance to the temperature upstream from the filter, deducing from this the local permeability of the filter and locally regenerating the filter.
Abstract:
The present invention is a filtering unit providing after-treatment of the gases emited in the exhaust of Diesel engines, comprising a filtering set which includes at least one filtering element (11, 12, 13); at least one resistive element (3) which heats a zone (121, 122, 123) of one of the at least one filtering element; at least one detection device which determines fouling of the filtering set (1); a control (5), responsive to the at least one detection device, which controls independently each of the resistive elements, according to the fouling of the filtering set and electrical power available to the at least one resistive element. The resistive elements (3) can be each wound around a zone of a filtering element. The invention further relates to the associated process.
Abstract:
The present invention relates to a method for regenerating a particle filter (10) arranged in the exhaust line (12) of an internal-combustion engine, notably of diesel type, wherein the clogging state of the filter is evaluated, this state is compared with a threshold value, then, if this threshold value is exceeded, a fluid and a fuel are mixed together, this mixture is subjected to catalytic combustion to generate the hot gases required for regeneration of the filter and regeneration of the filter is carried out by means of hot gases flowing through said filter and whose temperature is sufficiently high to provide combustion of the particles retained in this filter. According to the invention, prior to mixing the fluid and the fuel, the temperature of the fluid is raised up to the catalytic combustion light-off temperature.
Abstract:
The invention relates to a process for controlling a particulate filter in the exhaust of a Diesel engine using an after-treatment of the particulates while requiring a minimum amount of energy. The process according to the invention adapts the geometry of a filter placed in the exhaust gas flow according to predetermined strategies linked with the running of the engine, the process being such that it limits a mean back pressure of the engine which degrades engine efficiency.