FR2774422A1 - Assisted particle filter regeneration for diesel engine - Google Patents

Abstract

Energizing the catalytic converter heating elements serves to raise the temperature both of the exhaust gases passing from the converter to the particle filter and of the soot accumulated in the converter. The soot particles take fire, detaching themselves from the converter and further raising the temperature, leading to successful regeneration of the converter and filter. Typically, the engine's (1) exhaust system (2) includes a turbo compressor (3) followed by an electrically heated catalytic converter (8) and a particle filter (4), the last two items being closely associated or integrally constructed. A management unit (7) controls the fuel injectors (6) fed from a common rail (5) and also the converter heating elements. Energizing the latter serves to raise the temperature both of the exhaust gases passing from the converter to the particle filter and of the soot accumulated in the converter. The soot particles take fire, detaching themselves from the converter and further raising the temperature, leading to successful regeneration of the converter and filter.

Description

 The present invention relates to a system for assisting the regeneration of a particulate filter integrated in an exhaust line of a diesel engine, in particular of a motor vehicle.

 We know that one of the most important concerns of equipment manufacturers and motor vehicle manufacturers is the reduction of pollution caused by their operation.

This is particularly the case for motors
Diesel.

 Different solutions have therefore been envisaged in an attempt to reduce the pollution levels of these engines.

 Thus, for example, it has already been proposed in the prior art, to integrate particulate filters into the exhaust lines of these diesel engines.

 These are then adapted to trap particles or soot contained in the exhaust gases of these engines and burn them during a regeneration phase of the filter.

 Various means of assisting in the regeneration of these filters have already been developed in the state of the art.

 However, none of these are fully satisfactory.

 The object of the invention is therefore to solve these problems.

 To this end, the subject of the invention is a system for assisting the regeneration of a particulate filter integrated in an exhaust line of a diesel engine, in particular of a motor vehicle, characterized in that the particulate filter is associated with an electrically heated catalyst, arranged upstream of this filter and connected to means for controlling its supply to initiate regeneration of the filter.

 The invention will be better understood with the aid of the description which follows, given solely by way of example and made with reference to the appended drawing which represents a block diagram illustrating the general structure of a system for assisting regeneration. of a filter according to the invention.

 In fact, in FIG. 1, a system for assisting the regeneration of a particulate filter integrated in an exhaust line of a diesel engine, in particular of a motor vehicle, is recognized.

 In this figure, the engine is designated by the general reference 1 and the exhaust gases thereof are caused to circulate in an exhaust line designated by the general reference 2, associated for example with a turbocharger 3 if the engine is equipped with it.

 In this case, the exhaust gases are caused to circulate in the turbine portion of this turbocharger.

 Next, the exhaust gases are caused to circulate in a particle filter, designated by the general reference 4 in this figure, and having any suitable structure known in the state of the art.

 The engine is associated with a fuel supply system comprising for example a common supply device for injectors associated with the engine cylinders, also called COMMON RAIL in the prior art.

 This system is designated by the general reference 5 in this figure and is therefore associated with injectors with electrical control, for example, one of which is designated by the general reference 6 in this figure.

 The operation of these injectors is controlled by a central information processing unit designated by the general reference 7 in this figure.

 In addition, the particulate filter designated by the general reference 4, is associated with a catalyst, designated by the general reference 8 in this figure, with electrical heating, disposed upstream of this filter 4 in the exhaust line and connected to means for controlling its supply to start the regeneration of the filter.

 In the embodiment described, the means for controlling the supply of the electrically heated catalyst 8 are constituted by the central information processing unit 7.

 It is therefore understood that when this unit determines that the particle filter must be regenerated, it starts feeding the electrically heated catalyst 8 to increase the temperature.

 This then has a double effect.

 As the catalyst heats up, the temperature of the gases passing through it also increases before entering the particulate filter.

 In addition, this increase in temperature of the catalyst is transmitted to the soot accumulated thereon, which has the effect of igniting this soot and also makes it possible to heat the gases, which can be facilitated if the catalyst is impregnated.

 In addition, the ignited soots detach from this catalyst and also participate in increasing the temperature of the gases and of the particle filter to improve regeneration.

 Advantageously, the catalyst 8 is attached to the particle filter 4 and the latter can have any suitable structure, it will not be described in more detail below.

 It goes without saying of course that other embodiments of this system can be envisaged.

Claims (3)

 1. System for assisting the regeneration of a particulate filter (4) integrated in an exhaust line (2) of a diesel engine (1), in particular of a motor vehicle, characterized in that the filter (4) is associated with an electrically heated catalyst (8) disposed upstream of this filter and connected to control means (7) of its supply, to initiate the regeneration of the filter.  2. System according to claim 1, characterized in that the means for controlling the supply of the filter comprise a central information processing unit (7).  3. System according to claim 1 or 2, characterized in that the electrically heated catalyst (8) is attached to the particle filter (4).