System for sensing soot of diesel vehicle

A system for sensing soot of a diesel engine includes a combustion element which is a porous ceramic structure and to which a catalytic substance that is combustion-reacted with the soot is fixed, a comparison element which is the porous ceramic structure and to which a stable substance that is not combustion-reacted with the soot, and a detection section for detecting the temperatures of the combustion element and the comparison element and for deducing the soot formation amount among exhaust gas by using the temperature difference of the respective element.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority of Korean Patent Application Number 10-2012-0071125 filed Jun. 29, 2012, the entire contents of which application is incorporated herein for all purposes by this reference.

BACKGROUND OF INVENTION

1. Field of Invention

The present disclosure relates to a system for deducing the soot formation amount discharged from a diesel engine.

2. Description of Related Art

Generally, in a Diesel Particulate Filter (“DPF”) system the Particulate Matters (“PM”) remaining in a exhaust gas of a diesel engine are collected physically by using a filter and then PM is burnt out by increasing a temperature of the exhaust gas to an combustion temperature of PM or more after a vehicle travels at a predetermined distance.

The DPF system has been kwon as the best efficient technology for removing the soot among PM, however, an additional back pressure has to be applied to an engine and further the additional energy consumption is necessary for burning and reproducing periodically the traped-soot since the exhaust gas temperature has to be increased under the DPF system thereby affecting adversely fuel efficiency. Further, the discharged soot is affected greatly by an engine operation condition.

Accordingly, there needs a technology for sensing discharging amount of soot in real time in order to operate efficiently an engine and optimize DPF operation period.

Meanwhile, according to a related art, an optical sensor has been mainly used for sensing the soot and recently a Radio Frequency (“RF”) based sensor has been proposed, however, the RF based sensor is impossible to sense in real time selectively the soot and further costs high and has large volume and thus it has limitation to being mounted practically on a vehicle.

Accordingly, a development of a contact combustion type diesel soot sensor of a new concept that is applicable to a vehicle is necessary and further a development of a catalyst having selectively high combustion activity with respect to the soot is essential for implementing the contact combustion type soot sensor.

SUMMARY OF INVENTION

Various aspects of the present invention provide for a system for sensing selectively in real time soot formation amount among PM in exhaust gas of a diesel engine.

Various aspects of the present invention provide for a system for sensing soot of a diesel engine, including a combustion element which is a porous ceramic structure and to which a catalytic substance that is combustion-reacted with the soot is fixed, a comparison element which is the porous ceramic structure and to which a stable substance that is not combustion-reacted with the soot is fixed, and a detection section for detecting the temperatures of the combustion element and the comparison element and for deducing the soot formation amount among exhaust gas by using the temperature difference of the respective element.

The ceramic structure may include Al2O3.

The ceramic structure may include SiO2.

The stable substance may consist mainly of TiO2.

The catalytic substance may use TiO2 as a support and consists of a fixed element that is combustion-reacted with the soot.

The system for sensing soot of a diesel engine may further include a heating section for heating the combustion element so that the catalytic substance is combustion-reacted with the soot among exhaust gas.

The heating section may heat equally the combustion element and the comparison element.

The detection section may deduce the soot formation amount among exhaust gas by converting the temperature difference produced between the combustion element and the comparison element into electric signal.

It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention.

DETAILED DESCRIPTION

FIG. 1is a view showing a system for sensing soot of a diesel engine according to various embodiments of the present invention, referring toFIG. 1, the system for sensing soot of a diesel engine includes a combustion element100which is porous ceramic structure and to which a catalytic substance that is combustion-reacted with soot in exhaust gas of a diesel engine is fixed, a comparison element200which is porous ceramic structure and to which a catalytic substance that is stable and combustion-inactive with soot in exhaust gas of a diesel engine is fixed, and a detection section300for detecting the temperature difference between the combustion element100and the comparison element200and deducing the soot formation amount among the soot in exhaust gas by using the temperature difference of the respective element.

That is, the present invention relates to a system for sensing soot by using the catalyst that is positively and high active with respect to the soot and for deducing positively the soot discharging amount among PM in exhaust gas discharged from a diesel engine.

Specially, the system for sensing the soot is configured by the combustion element100to which the catalytic substance that is high combustion-active with respect to the soot is fixed and the comparison element200that is stable and combustion-inactive with respect to the soot wherein when the combustion element100is heat-reacted with the soot and thus temperature increases, the temperature difference between the combustion element and the comparison element200is detected through the detection section to deduce the soot discharging amount.

Here, the combustion element100may consist of Ag as the catalytic substance that is selectively combustion-reacted with the soot and the catalytic substance is fixed to the porous ceramic structure. Meanwhile, the comparison element200is a comparison means for measuring the combustion heat amount produced when the combustion element200is combustion-reacted with the soot and further may consist mainly of TiO2 that is not combustion-reacted with the soot.

Accordingly, the temperature variation and the temperature difference between the combustion element100which consists of the catalytic substance that is positively combustion-reacted with the soot and the comparison element200which consists of stable substance that is not combustion-reacted with the soot are measured through the detection section300to deduce the soot formation amount and then convert it into electrical signal thereby sensing the soot formation amount in real time.

Meanwhile, the ceramic structure constituting the combustion element100and the comparison element200may comprise Al2O3 or SiO2 as a porous structure.

Of course, the ceramic structure may comprise other materials, however, it may comprise Al2O3 or SiO2, since Al2O3 or SiO2 is stable as the structure and is not catalytic-active with respect to the soot and is not reacted with other materials. Further, the ceramic structure may be porous such that the catalytic substance and other materials are fixed thereto.

Meanwhile, the stable substance that is fixed to the comparison element200may consist mainly of TiO2. The present invention intends to deduce the soot formation amount by using the temperature difference between the combustion element100that is selectively combustion-reacted with the soot in exhaust gas of a diesel engine and the comparison element200that is not combustion-reacted with the soot wherein the substance that is not combustion-reacted with the soot has to be used in the comparison element. Accordingly, TiO2 as the stable substance that is not combustion-reacted with the soot is comprised in the comparison element. Further, the more TiO2 which is fixed to the ceramic structure is comprised, the more the effect as the stable substance increases and pure TiO2 may be very suitable.

Meanwhile, the catalytic substance may use TiO2 as a support and Ag that is combustion-reacted with the soot may be fixed thereto, that is because that the support of the catalytic substance that is fixed to the combustion element100and the stable substance that is fixed to the comparison element200consist of TiO2 and thus the combustion heat amount produced through the combustion reaction with the soot can be quantified. Further, in case of Ag used in the catalytic substance, since Ag has selectively and high catalytic activity with respect to the soot, Ag may be utilized as an element that is fixed to the catalytic substance of the combustion element.

As a result, the temperature difference between the combustion element100and the comparison element200is produced to deduce the soot discharging amount and, the support of the catalytic substance that is fixed to the combustion element100and the stable substance that is fixed to the comparison element200consist of TiO2 and thus the temperature difference caused from the combustion reaction can be measured accurately.

Meanwhile, the present invention further includes a heater section400for heating the combustion element100such that the catalytic substance is to be combustion-reacted with the soot in exhaust gas. Generally, the exhaust gas temperature of a diesel engine is not enough burn the soot and thus the heater section heats the combustion element100to a predetermined temperature so that the catalytic substance is combustion-reacted with the soot.

As a result, the combustion element100is catalytic combustion-reacted with the soot and thus the soot formation amount among the exhaust gas can be deduced by using the temperature difference between the combustion element100of increased temperature the comparison element200.

Specially, the heater section400may heat equally the combustion element100and the comparison element200that is because that in addition to the temperature difference caused from the combustion reaction of the combustion element100with the soot, when the temperature difference is caused from heating only the combustion element100or other conditions, the accurate deducing of the soot formation amount of the combustion element100and the comparison element200is limited. Accordingly, the heater section400may heat equally the combustion element100and the comparison element200in order to quantify the temperatures of the combustion element100and the comparison element200.

Meanwhile, the detection section300may deduce the soot formation amount in exhaust gas by converting the temperature difference produced between the combustion element100and the comparison element200into electric signal.

In more detailed description, the temperature difference between the combustion element100and the comparison element200can be deduced by using a contact combustion type sensor. When the combustion element100contacts the soot among exhaust gas and is combustion-reacted to increase temperature thereby increasing electric resistance. At this time, the electric resistance variation is converted into electric signal and the soot formation amount can be deduced by comparing the electric signal to the electric signal of the comparison element200. As a result, the soot formation amount cab be confirmed in real time and prompt management thereto can be made.

According to the system for sensing the soot of a diesel engine, the soot formation amount can be deduced and sensed in real time by applying the catalytic substance having high combustion-activity with respect to the soot among PM in exhaust gas discharged from a diesel engine to the combustion element.

Specially, according to the system for sensing the soot of a diesel engine, the soot formation amount can be sensed by using the temperature difference between the combustion element consisting of the catalytic substance that is high combustion-active with respect to the soot and the comparison element that is not combustion-inactive with respect to the soot.