KR100782131B1 - Internal combustion engine exhaust gas heater - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater configuration of an internal combustion engine exhaust gas purifier that drives DME, LPG, LNG, gasoline, diesel, biodiesel, or oxygenated hydrocarbons, as a raw material. It consists of a supply device.

According to the installation of the exhaust gas suction unit, the reformed gas combustion is induced by utilizing the oxygen contained in the exhaust gas. When the heater is driven, air and fuel are supplied to the reformer and the secondary fuel supply in a single conduit.

This ensures the durability of the exhaust gas heater by eliminating the carbon deposition in the fuel supply conduit by DME pyrolysis, which is LPG, LNG, gasoline, diesel, biodiesel, or oxygen-containing hydrocarbons, supplied to the combustion reformer. Provided is an exhaust gas heating device and a method of operation that can minimize external air supply.

Diesel cars, exhaust gas heating, hydrocarbon combustion, hydrocarbon reforming

Description

Heating device for exhaust gas in internal-combustion engine

1 is a block diagram of a DPF heating system using a conventional fuel injection

2 is a block diagram of a DPF heating system using a fuel evaporator of the prior art

3 is a block diagram of a DPF heating system according to the present invention

4 is a specific example of an exhaust gas heating apparatus according to Embodiment 1 of the present invention.

5 is a configuration example of the exhaust gas intake portion according to Embodiment 2 of the present invention;

6 is a configuration example of the exhaust gas intake portion according to Embodiment 3 of the present invention;

7 is a configuration example of the exhaust gas heating device according to a fourth embodiment of the present invention

8 is a change in experimental conditions according to Example 3

9 is an experimental result diagram according to Example 3

10 is a test result diagram according to Example 3

<Description of Symbols for Main Parts of Drawing>

10, 20, 30: engine 11, 22, 2000: DOC

12, 23, 3000: DPF 21: Evaporator

40: differential pressure gauge 100: housing

130,131,132,133: igniter connector 140,141,142,143: igniter connector

150,151,152,153: Power supply lines 170,171,172,173: Igniter

200,203 Mixer 300,303 Primary fuel supply line

310,313: Primary air supply line 320,323: Primary fuel preheating line

600,603: Secondary fuel supply line 610,613: Secondary air supply line

620,623: Nozzle 630,633: Secondary fuel preheating line

500,501,502,503: reactors 510,511,512,513: combustion reforming catalyst

520,521,522,523: Separator 700,703: Introduction

713: suction cone 900,901,902,903: ignition unit

910,911,913: Inlet hole 920: Combustion zone

931 introduction phase 932 introduction tube

1200,1300: exhaust gas heater

The present invention relates to an internal combustion engine exhaust gas heating apparatus, and more particularly, an internal combustion engine for driving DME (hereinafter referred to as 'fuel'), which is LPG, LNG, gasoline, diesel, biodiesel, or oxygenated hydrocarbon, as a fuel. It relates to an internal combustion tube exhaust gas heating apparatus required for heating the exhaust gas purifying apparatus.

Vehicles driven by internal combustion engines are a major cause of urban pollution by continuously emitting particulate materials and nitrogen oxides, and environmental regulations on vehicles are being strengthened day by day.

As a method to remove these pollutants, the company has made efforts to reduce emissions of pollutants by maximizing engine efficiency and fuel quality, and to exhaust gas aftertreatment such as particulate removal filter and nitrogen oxide removal catalyst. Research is underway.

Nevertheless, the exhaust gas aftertreatment process is very dependent on the vehicle conditions and operating conditions, so the application is very limited.

At present, there have been attempts to utilize the electric heating method and the combustion heat using a burner as an energy source for filter regeneration. However, in order to apply the system, it is necessary to overcome difficulties such as limited power available or space for installing an external burner. do.

Recently, a number of concept patents have been applied to form a reducing gas through heating and / or reforming the exhaust gas by supplying hydrocarbons in the exhaust gas, but it does not present a specific system configuration necessary for its combustion / reformation.

When hydrocarbon is injected into the exhaust gas, recondensation proceeds at a temperature lower than the boiling point of the diesel fuel, and a separate exhaust gas heating device is required to suppress this.

As a complementary method, a method of converting a vapor into a vapor using an evaporator using electricity and then mixing it in the exhaust gas and burning it on a DOC (Diesel Oxidize Catalyst) is disclosed.

However, when the DOC temperature is 235 ° C. or lower, combustion of the vaporized diesel is impossible, and it is necessary to prepare for recondensation of the vaporized fuel at a low exhaust gas temperature, thereby limiting the fuel injection timing.

FIG. 1 is a general configuration diagram of DPF heating by fuel injection, in which fuel for assisting a heat source to exhaust gas from the engine 10 is mixed with the exhaust gas and flows into the DOC 11, and the DOC 11 The exhaust gas and the fuel are oxidized to generate heat, which is used as a heat source that the DPF (Diesel Particulate Matte Filter) 12 can reproduce.

The DOC 11 burns a soluble organic fraction (SOF) and fuel for heating the DPF from carbon monoxide, hydrocarbons, and particulate matter contained in exhaust gas.

The DPF 12 has a configuration arranged in series at the rear end of the diesel oxidation catalyst (DOC), and suppresses particulate matter discharge by collecting particulate matter from the diesel engine in the filter, and when the particulate matter is collected more than a predetermined amount is supplied to the outside Particulate matter is burned and regenerated by a heat source.

In FIG. 1, heat generated from the DOC 11 is used.

FIG. 2 further includes a fuel evaporator 21 as compared with FIG. 1, which vaporizes and supplies fuel (especially diesel) to the exhaust gas to improve mixing with the exhaust gas, thereby improving DOC 22. It promotes the oxidation reaction in).

Internal combustion engine exhaust gases, in particular in diesel vehicles, collect particulate matter into a filter (metal or ceramic material) and continuously oxidize or / or periodically burn at the same time to regenerate the filter.

The regeneration period of the filter has fluidity according to the temperature distribution NO / soot ratio of the exhaust gas. The temperature of the exhaust gas depends on the vehicle model, engine type, road conditions and traffic congestion, and the NO / soot ratio is also variable according to the EGR ratio.

In other words, in order to adjust the temperature of the exhaust gas in consideration of the performance of the aftertreatment device, it is impossible to change the operating conditions of the engine (operation vehicle), and an independent heating system for heating the exhaust gas is required if necessary. Is in.

In order to achieve this object, the present applicant has proposed a system configuration capable of regenerating a DPF independently of vehicle operating conditions by placing a small catalytic reactor in an exhaust gas pipe to perform a partial oxidation reaction of fuel. No. 10-2005-92205, 10-2005-92765).

In the above configuration, the system is configured to supply air from the outside using an air compressor as a source of oxygen required for the partial oxidation reaction or to suck in a part of the exhaust gas and use it as a source of oxygen as an oxidant.

However, in the above construction method, the reactor in the form of supplying air from the outside needs to compensate for the problem that the power usage is increased in order to supply a large amount of air, and in the air suction type reactor, it is prepared for the catalyst contamination by the exhaust gas. Need.

In addition, it is preferable to install a recuperator to induce evaporation using fuel combustion heat when supplying the secondary fuel, but coke deposition occurs in the supply line during a long time operation, requiring periodic maintenance.

An object of the present invention devised to solve the above problems is to provide an exhaust gas heating apparatus that can minimize the amount of air supplied to the catalytic reactor for reforming reaction.

It is still another object of the present invention to provide a system configuration and operation method for eliminating coke formation inside a hydrocarbon feed tube into an exhaust gas heater.

Still another object of the present invention is to provide an apparatus for producing a reducing gas for removing nitrogen oxide, which supplies a reducing gas for removing nitrogen oxide from a predetermined gas, including an internal combustion engine exhaust gas heating device.

In order to achieve the above object, the present invention provides an exhaust gas suction hole at a rear end of the catalytic reformer so as to be delivered (intake) into the reforming reactor to induce ignition of the reducing gas discharged from the reforming reactor from the outside. Minimize the air supply and use the oxygen contained in the exhaust gas as the oxidant.

The present invention is also characterized by simultaneously supplying air as an oxidant to a conduit for supplying fuel to a catalytic reformer equipped with a combustion reforming catalyst and an electrothermal heater in an exhaust gas pipe.

The exhaust gas suction hole is positioned at a rear end of the reforming catalyst layer to burn the reformed gas to secure a high heat portion capable of evaporating and igniting secondary fuel.

As such, by utilizing the oxidant contained in the exhaust gas, the external air supply can be significantly lowered.

Accordingly, it is possible to minimize the electrical energy consumption required to drive the air compressor.

In addition, the reactor configured to introduce a part of the exhaust gas into the catalytic reactor minimizes the exhaust gas intake and inhales the oxidant through the secondary suction having a relatively low pressure loss, thereby minimizing the pressure loss in the exhaust pipe to reduce fuel consumption. can do.

The fuel / air supply line of the present invention is formed to increase the residence time and heat transfer area for evaporating the fuel therein.

In addition, the fuel / air supply line is characterized in that it has a spiral shape running in the longitudinal direction of the tube inside the tube.

In the fuel and air injection, the fuel supply and the air supply are alternately injected at a time difference.

In addition, the present invention is located in the hot portion formed by the reformed gas ignition heating and / or at the same time the reforming portion of the fuel and the outlet portion of the reformed gas at a position below 400 ℃ (variable depending on the engine type) to suppress its natural ignition to the catalyst surface I can deliver it.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described. In adding reference numerals to components of the following drawings, it is determined that the same components have the same reference numerals as much as possible even if displayed on different drawings, and it is determined that they may unnecessarily obscure the subject matter of the present invention. Detailed descriptions of well-known functions and configurations will be omitted.

In the present invention, by placing the catalytic reactor inside the space in which the exhaust gas moves to ensure the cooling action of the heater by the exhaust gas while inducing hydrocarbon combustion using the oxygen contained in the exhaust gas and utilizing the heat generated in the process It is possible to proceed with heating of the post-device (DOC, DPF), catalyst for De-NO _X or NO _X trap not shown in the figure.

In addition, in the present invention, a secondary fuel injection unit is provided at the rear end of the catalytic reactor.

And preheating or evaporation zones are provided to allow heating up to 350 ° C. or higher to achieve gasification prior to secondary fuel / air injection. Its heat source does not require a separate heating device and is installed in the high heat section after the catalytic reactor.

In addition, the secondary fuel / air supply line provides ease of system control when giving heat exchange / recuperators for heating the introduced fuel by self-heating.

At this time, the most important matter is that the fuel / air injection nozzle of the secondary fuel / air supply line is preferably located near the rear end of the reforming reactor, so that the secondary fuel may ignite even if the reformer capacity is small.

More preferably, when the preheating portion is positioned at the rear end of the secondary fuel / air supply nozzle, the ignition is more easily performed because the secondary fuel / air mixture gas or the fuel may be preheated / evaporated by the self-heating. Providers can be ruled out.

The shape of the heating / evaporator located at the rear end of the secondary fuel / air supply nozzle is preferably a shape that provides a space that can be contacted with high heat while minimizing the influence on the gas flow, and there is no particular limitation.

According to the heating / evaporation device, two or more units are installed in series or in parallel according to the applied vehicle (exhaust amount), so that temperature uniformity and heating capacity in the heater can be expanded.

That is, according to the exhaust gas capacity, the basic size of the catalytic reactor is kept the same, thereby forming a local high temperature part and installing a plurality of feeders in series or in parallel on the downstream side of the gas flow, thereby responsiveness and temperature uniformity to the application scale. Can improve.

In addition, the heating and recuperators can utilize a heat source generated by ignition when positioned behind the secondary fuel / air supply nozzle, so that a large amount of fuel can be vaporized / burned and supplied, which is a preferable configuration.

In addition, when the combustion in the DOC through the simple evaporation or reformation without the secondary fuel is not ignited, with the increase of the capacity of the DOC, it can be injected only in the combustion temperature conditions.

Therefore, in the present invention, since the secondary fuel is ignited to burn most of the fuel, there is an additional advantage that the DOC can be excluded or kept small when the present heater is applied.

The most important part of the present invention is to have an exhaust gas suction hole at the rear of the reforming reactor so that the exhaust gas is mixed with the reformed gas. In addition, the fuel is mixed with air or injected, or air and fuel are alternately injected to prevent clogging due to carbon deposition in the fuel supply line.

Another invention is a nitrogen oxide removal reducing gas production apparatus for producing a reduction gas for nitrogen oxide removal from a predetermined gas, including the internal combustion engine exhaust gas heating apparatus.

At this time, it can be obtained by increasing the amount of fuel supplied through the fuel / air supply line or by reducing the amount of exhaust gas introduced into the reactor to induce incomplete combustion. In order to obtain a larger amount of reducing gas, the preheating part is placed in the high temperature part at the rear part of the reactor to proceed pyrolysis of the fuel, and the nozzle, which is its discharge part, is placed in a temperature region where the reducing gas cannot be ignited so that the reducing agent is mixed in the exhaust gas. Can be used as a reducing agent for NOx removal.

Hereinafter, the present invention will be described in detail through examples and drawings.

3 is a configuration diagram of a DPF heating system according to the present invention, in which the exhaust gas heating apparatuses 1200 and 1300 are installed instead of the fuel supply method of FIG. 1 or 2.

Fuel may be used in the same kind of vehicle for convenience, and may be used in the same place, for example, in the case of a small power generator may utilize a different type of hydrocarbon, the air oxidant is supplied through an external compressor.

4 schematically shows an exhaust gas heating apparatus 1200 according to Embodiment 1 of the present invention.

As illustrated in FIG. 4, the exhaust gas heating device 1200 includes a reactor 500, an igniter 170, an ignition unit 900 by introducing exhaust gas, and injection means for secondary injection of fuel. And a housing 100 including the mixer 200 of the combustion gas and the exhaust gas and the exhaust gas moving space to form an independent component for performing exhaust gas heating. The mixer may achieve the same purpose even if it is located outside the housing 100 according to the heater mounting convenience.

Side of the ignition unit 900 has a plurality of inlet holes 910 so that exhaust gas is introduced into the combustion zone 920. The inlet hole 910 has a small number is formed in the first half of the combustion zone, a large number is formed in the second half of the combustion zone, so that the air introduced through the inlet hole 910 is gradually increased.

In addition, a separation plate 520 having a plurality of holes is installed between the ignition unit 900 and the reactor 500 to fix the combustion reforming catalyst 510.

Although the shape of the reactor 500 is not limited, as shown in FIG. 4, the cross-sectional area of the inlet 700 for introducing the exhaust gas and the fuel is a combustion reforming catalyst 510 in consideration of volume expansion as the combustion proceeds. Smaller than the cross-sectional area of the reaction section to be modified by

When the introduction portion 700 and the reaction portion maintain a cross-sectional ratio of 0.1 to 0.9, the ignition proceeds quickly and the slip of unburned hydrocarbon can be minimized.

Accordingly, the above-mentioned catalytic reactor has a shape in which two tubular bodies having different diameters have tapered joints, which are roughly in the form of funnels.

Since the catalytic reactor 500 used in the present invention can proceed to ignition through local heating, regardless of the operating conditions (exhaust gas temperature) of the vehicle, the exhaust gas heating device (exhaust gas temperature 100 ℃) ( 1200) to supply a reducing agent for heating and removing nitrogen oxides of the DPF.

In particular, the operating method for maximizing the performance of the preferred reactor 500, the primary fuel preheating line for preheating the fuel supplied to the inlet 700 by heat exchange with the combustion gas passing through the catalytic reactor 500 320 is located at the rear of the reactor 500.

The primary fuel preheating line 320 is connected to the primary fuel supply line 300 connected to an external fuel supply source (not shown), and is bent several times in the housing 100 to maximize the contact area with the combustion gas. Let's do it.

In addition, the primary fuel supply line 300 is connected to the primary air supply line 310 for supplying air to assist combustion. This is to supply air to the primary fuel supply line (300) at the same time, in order to suppress the conduit membrane by coke generation by fuel pyrolysis.

In addition, in the exhaust gas heating apparatus 1200 according to the first embodiment of the present invention, a secondary fuel preheating line 630 for supplying secondary fuel to the rear end of the reactor 500 inside the housing 100. And the nozzle 620 is mounted to the terminal portion of the secondary fuel preheating line 630.

The secondary fuel preheating line 630 and the nozzle 620 are positioned between the primary fuel preheating line 320 and the reactor 500.

The secondary fuel preheating line 630 is connected to a secondary fuel supply line 600 connected to an external fuel supply source (not shown), and is bent several times in the housing 100 to maximize the contact area with the combustion gas. Let's do it.

In addition, the secondary fuel supply line 600 is connected to a secondary air supply line 610 for supplying air to assist combustion. This is to supply air to the secondary fuel supply line 600 at the same time, in order to suppress the inside of the nozzle 620 and the conduit membrane by coke generation by fuel pyrolysis.

Therefore, since the coke generated for a predetermined time can be removed by intermittently supplying air to the primary fuel preheating line 300 and the secondary fuel preheating line 600, the conduit can be minimized while supplying air from the outside. Can be suppressed.

In addition, since the reaction rate is very fast at a high temperature of 800 ° C. or higher due to the characteristics of the combustion reforming catalyst 510, the space velocity of the reactant can be maintained very high (200,000 / hr or more), thereby minimizing the amount of precious metal as a reforming catalyst. .

The cross section of the reaction part filled with the combustion reforming catalyst 510 of the catalytic reactor 500 according to Embodiment 1 may be circular or polygonal, and the shape thereof is not limited. Preferably, the reactor diameter / diagonal of the expanded portion is suitably 50 mm or less. More preferably 40 mm or less is recommended.

The combustion reforming catalyst 510 is not particularly limited, and both a combustion catalyst and a reforming catalyst known in the art may be used.

An igniter 170 is installed at the introduction portion 700 of the catalytic reactor 500, and the igniter 170 is inserted into the igniter connector 130 installed on the wall of the housing 100. It is connected to, and is supplied with power by the power supply line 150 penetrating through the igniter connecting pipe 140.

In addition, the mixer 200 is installed at the lower end of the housing 100 and serves to mix the reformed gas and the exhaust gas that does not pass through the catalytic reactor, so that uniform fuel is supplied to the DOC that will burn the reformed gas. Suppress the loss of DOC.

The catalytic reactor 500 according to the present invention uses a mixture of an oxidation catalyst and a reforming catalyst.

However, in order to enhance the oxidizing power, it is preferable to use 80% by weight or more of the content of the oxidation catalyst. More preferably, 100 wt% of an oxidation catalyst is used at the inlet through which diesel oil and air (or exhaust gas) are introduced, and it is preferable to install the dividing catalyst by 100% at the second half of the reactor. In the examples, the results using 100% by weight oxidation catalyst were shown.

5 is a schematic cross-sectional view of a reactor 501 according to Embodiment 2 of the present invention. Parts not shown in FIG. 5 are the same as those in FIG. 4, and like reference numerals are used in the following description.

The reactor 501 according to the second embodiment is the same as the reactor 500 of the first embodiment, but in order to increase the capacity by increasing the amount of exhaust gas introduced into the ignition unit 901, as shown in FIG. An introducer 931 is provided outside the hole 911 to concentrate the exhaust gas toward the inflow hole 911.

The introducer 931 has a substantially cone shape, and is installed to have a smaller diameter toward the rear end of the complexing part 901.

Therefore, compared with the ignition unit 900 of the first embodiment, it is possible to greatly increase the amount of exhaust gas flowing into the inlet hole 911.

6 is a schematic cross-sectional view of a reactor 502 according to Embodiment 3 of the present invention. Parts not shown in FIG. 6 are the same as those in FIG. 4, and like reference numerals are used in the following description.

In the third embodiment, as shown in FIG. 6, in order to increase the capacity by increasing the amount of exhaust gas introduced into the ignition unit 902, as shown in FIG. An introduction pipe 932 is installed.

As in the first embodiment, the direction of the inflow hole formed in the ignition unit 902 and the direction of the exhaust gas flowing around the ignition unit 902 are approximately vertical.

Therefore, the exhaust gas is introduced into the inlet hole by the pressure difference inside and outside the ignition unit 902. Therefore, in order to assist this by installing a bent tube-shaped inlet tube 932 that can forcibly match the direction of the exhaust gas with the direction of the inlet hole, it is possible to improve the amount of exhaust gas introduced through the inlet hole. .

In comparison with Example 2 and Example 3, the preferred form is the form of Example 2, the reformed gas ignition because it can be heated to the exhaust gas while passing through the high temperature of the upper catalytic reactor with a compact appearance It is effective because it can proceed faster.

7 schematically shows an exhaust gas heating apparatus 1300 according to Embodiment 4 of the present invention.

As another configuration in which the effects of the present invention can be obtained, as shown in FIG. 7, a portion of the exhaust gas may be introduced into the exhaust gas without supplying air required for the reactor 503 from the outside.

That is, the suction cone 713 for sucking the exhaust gas is integrally mounted at the front end of the inlet 700.

Due to this configuration, it is possible to minimize the power used for supplying air to the primary fuel.

The heater 1300 according to the fourth embodiment is configured in the same manner as in the first embodiment except that the suction cone 713 is mounted.

Next, the production method of the combustion reforming catalyst 510 used in the present invention will be described as follows.

Platinum was used as the active ingredient and alumina was used as the support. Prior to supporting the precious metal as an active metal, cerium nitrate (Ce (NO ₃ ) ₂ .xH ₂ O, Aldrich product) was dried and dried in 3-5mm granular activated alumina (gamma-Al ₂ O _3, canto product). 105 ° C., 24 hours), and then calcined at 1300 ° C. for 12 hours. Platinum chloride (H ₂ PtCl ₆ .xH ₂ O, manufactured by Hangeol Gold Co.) was dissolved in distilled water on the finished composite support to support platinum. Each precursor was added to include 10% by weight of cerium and 0.2% by weight of platinum based on the total weight of the support. After supporting platinum, drying (105 ° C., 24 hours) and firing (1000 ° C., 24 hours) were completed (Pt / Ce / Al ₂ O ₃ ).

There are no particular limitations on the form or material properties of the DPF, which is a heated object, by heating the exhaust gas using the catalytic combustion apparatuses 1200 and 1300 according to the present invention. It can be applied to various types of filters, such as monolithic, foamy, and granular, composed of ceramic, metal, SiC, or SiN.

However, since the filter may be locally overheated by the combustion of the collected PM, at least 900 ° C. or higher heat resistance is required.

In addition, a method of lowering the operating temperature through the coating of a noble metal oxide catalyst or a nitrogen occluding metal may also be used in the filter thereof.

Main measurement positions and items for operating the DPF heating system according to the present invention are as follows.

-Differential pressure before and after DPF (ΔP)

-Exhaust gas temperature (T1) flowing into the catalytic combustor (500)

-Catalytic burner (500) exhaust gas temperature (T2)

-Secondary combustion exhaust gas temperature (T3)

-Exhaust gas temperature at the DOC inlet (T4)

-Exhaust gas temperature (T5) at DOC outlet and DPF inlet

-Exhaust gas temperature at the DPF outlet (T6)

When pressure loss (ΔP) of the DPF is detected at a pressure loss higher than a reference value due to an increase in the amount of particulate matter collected, the igniter is supplied with power to heat the combustion reforming catalyst 510.

At this time, if the temperature of T1 is 350Δ or more, the power supply process may be omitted. When the temperature of the catalytic reactor 500 is 350 ° C. or lower, power is supplied for 5 to 600 seconds and fuel is supplied.

When the discharge temperature (T2) of the catalytic reactor 500 reaches 300 ℃ or more, the power supply of the heater is stopped.

The amount of fuel supplied to the catalytic reactor 500 is increased to increase the combustion gas discharge temperature T3 to 600 ° C. or higher.

The secondary fuel / is supplied to maintain the temperature of T5 at 500 ° C or higher to proceed with the regeneration of the DPF 3000.

Regeneration is performed by supplying fuel until the filter differential pressure? P is lowered below the reference value.

A safety mode is included in the ECU that prevents the loss of the filter by adjusting the fuel supply amount so that the filter outlet temperature T6 does not reach 650 ° C. or more (variable according to the heat resistance of the DPF).

Hereinafter, the test results of the internal combustion engine exhaust gas heating apparatus according to the present invention will be described in detail. Example 3 was used as a test example.

[Test Example 1]

The reactor 502 uses a 3/4 "tee made of stainless 316 as the air and fuel inlet 702, and the reactor 502 uses a stainless steel 316 inner diameter 35 mm pipe to reduce the diameter of the igniter portion. 35 mL of the combustion catalyst (Pt / Ce / Al ₂ O ₃ ) described in the detailed description of the invention was charged to the reactor 502.

The ignition unit 902 joins two 1/4 "elbows and four 3/8" elbows to the side of a tube having the same diameter as the reactor 502 to follow the configuration of Figure 6 to exhaust gas in the reformed gas. Mixed.

The gas introduction part was manufactured by connecting an initial heating igniter 172 and an air and fuel supply line. The heater used a commercial product (heating plug for diesel vehicles) equipped with a heater at the end of the screw to be disassembled and assembled from the outside.

The secondary fuel supply was made using 1/8 "stainless steel tubing.

The reactor 502, the ignition unit 902, the primary fuel preheating line 320, and the secondary fuel preheating line 630 were installed in the housing 100 having an inner diameter of 10 cm and a length of 25 cm.

The heater was mounted in the vehicle exhaust vent in the order of FIG. 3 and the performance was measured. However, the inlet and outlet temperatures (T4, T5) and the ambient temperature (T1, T2) of the exhaust gas heating device (1200) of the DOC (2.5 liter engine commercial product) were measured without the DPF (3000).

In the experiment, a 2.5 liter diesel vehicle equipped with a supercharger was used. After the engine was started, the exhaust gas heating state was monitored using the exhaust gas heating device 1200 under the condition that the no-load idle rotation (1300 rpm) was maintained for 30 minutes and the exhaust gas temperature was maintained at a steady state.

The igniter 171 was supplied with 24V DC power for 3 minutes and started by supplying air and fuel. After ignition, the air and fuel supply amounts were changed as shown in FIG. Air was supplied using a compressor, and diesel oil was supplied using a liquid pump. The temperature of each part over the experiment time was monitored at 1 second intervals.

As shown in FIG. 9, the exhaust gas of 100 ° C. or less was heated to 550 ° C. or more, which is a regeneration temperature of the DPF.

In addition, the fuel supply amount and the DOC trailing temperature were obtained in a linear relationship as summarized in FIG.

As described above, it has been described with reference to the preferred embodiment of the present invention, but those skilled in the art various modifications and changes of the present invention without departing from the spirit and scope of the present invention described in the claims below I can understand that you can.

The exhaust gas heating apparatus according to the present invention can heat the exhaust gas to a required temperature independently of the load and rotation state of the engine. Therefore, it is expected to be utilized as a core module required for the construction of the third generation DPF system for small and medium-sized diesel vehicles, which is difficult to reproduce itself.

Claims (12)

Housing of tubular body; The combustion reforming catalyst is filled in the housing so as to burn / reform the exhaust gas, and has an inlet for installing an electrothermal heater at the front end, and a primary fuel preheating line connected to the outside of the housing to supply fuel is installed. Reactor; An ignition unit integrally installed at the rear end of the reactor and configured to combust some mixed combustible material of combustion reformed gas discharged from the reactor and exhaust gas flowing between the reactor and the housing; A nozzle installed at a rear end of the ignition unit to receive fuel from a secondary fuel preheating line and to inject fuel into the exhaust gas to secondary combustion of the exhaust gas; And And a mixer installed at a rear end of the catalytic reactor and mixing a combustion gas passing through the combustion catalyst and exhaust gas flowing between the catalytic reactor and the housing. The internal combustion engine exhaust gas heating apparatus according to claim 1, wherein a separation plate having a plurality of holes is provided between the reactor and the ignition unit to allow combustion reforming gas to pass while fixing the combustion reforming catalyst. The internal combustion engine exhaust gas heating apparatus according to claim 1, further comprising a suction cone for sucking exhaust gas at a front end of the inlet of the reactor. The internal combustion engine exhaust gas heating apparatus according to claim 1, wherein the primary fuel preheating line and the secondary preheating line are bent several times in the housing. The method of claim 1, wherein the primary fuel preheating line and the secondary preheating line are respectively connected to the primary fuel supply line and the secondary fuel supply line, respectively, the air in the primary fuel supply line and the secondary fuel supply line, respectively Exhaust gas heating apparatus characterized in that the primary air supply line and the secondary air supply line for supplying simultaneously. The exhaust gas heating apparatus according to claim 5, wherein air and fuel are alternately supplied to the primary fuel preheating line and the secondary preheating line. The exhaust gas heating apparatus according to claim 1, wherein a plurality of inlet holes are formed on an outer circumferential surface of the ignition unit for introducing exhaust gas from the outside. The exhaust gas heating apparatus according to claim 7, wherein the inflow hole increases in number or diameter of the inflow hole toward the rear end of the ignition unit to increase the inflow amount of the exhaust gas. 8. The exhaust gas according to claim 7, wherein an introducer is further installed to assist inflow of exhaust gas through the inlet hole around the ignition unit, and the inlet introduces a cone shape so that the cross-sectional area decreases toward the rear end of the ignition unit. Gas heater. According to claim 7, wherein the inlet is further provided with an inlet pipe is integrally installed to assist the inlet through the inlet through the exhaust gas, the inlet pipe is bent to a portion perpendicular to the portion parallel to the exhaust gas Exhaust gas heating apparatus, characterized in that configured. A method for heating a catalyst or trap for removing nitrogen oxides by using the exhaust gas heating apparatus according to any one of claims 1 to 10. A method for supplying a reducing agent for removing nitrogen oxides using the exhaust gas heating apparatus of any one of claims 1 to 10.

Images