JP4344684B2 - Exhaust gas purification device for internal combustion engine - Google Patents

Description

The present invention relates to harmful substances such as nitrogen oxides (NO _x ), hydrocarbons (HC), carbon monoxide (CO), and fine dust particles (PM) contained in the exhaust gas of internal combustion engines such as automobile diesel engines. The present invention relates to an exhaust gas purification device that effectively reduces the above.

  As a countermeasure for automobile exhaust gas, which is a major cause of air and environmental pollution, a purification system for reducing harmful substances by a catalyst mechanism and a combustion mechanism has been developed for ordinary passenger cars and light passenger cars. However, for exhaust gas from large vehicles that use diesel engines such as trucks and buses, in addition to harmful chemical substances such as nitrogen oxides, hydrocarbons, and carbon monoxide, a large amount of fine dust particles that make the exhaust blackish However, a sufficiently effective purification method has not been found, and countermeasures are urgently needed.

Therefore, the present inventors have previously described a structure in which a large number of strong magnets are arranged at predetermined intervals in the axial direction in a cylindrical casing interposed in a fuel oil supply path as a harmful exhaust gas reduction device for an internal combustion engine or the like (patented) Documents 1 and 2), a structure filled with a far-infrared ceramic piece (Patent Document 3), a structure in which a strong magnet is arranged at the center and a far-infrared ceramic is filled at both ends (Patent Documents 4 and 5), fuel Proposals have been made for oil to pass through these strong magnets, far-infrared ceramics, or both. Furthermore, the present inventors, as an exhaust gas purifying device for an internal combustion engine or the like, have a cylindrical structure in which a metal net is wound around the outer periphery of a cylinder made of a punching plate in a cylindrical casing interposed in an exhaust gas passage. A structure in which a metal net filter is provided, and a far-infrared ceramic sphere is filled inside the cylindrical metal net filter (Patent Document 6), and a far-infrared ceramic sphere is filled between inner and outer cylinders made of the same cylindrical metal net filter. A structure in which a heater is inserted in the packed bed (Patent Document 7) and exhaust gas passes through a cylindrical metal net filter and a far-infrared ceramic sphere packed bed is also proposed.
Registered Utility Model No. 3023699 Published Japanese Patent Laid-Open No. 9-209850 Registered Utility Model No. 30277705 Registered Utility Model No. 3012857 Registered Utility Model No. 3025486 JP 2003-20927 A JP 2003-20934 A

  Thus, in the proposed harmful exhaust gas reduction device, the fuel oil comes into contact with the strong magnet or the far-infrared ceramic so that the fuel oil molecules are activated by the action of magnetism or far-infrared radiation, and the combustion efficiency in the internal combustion engine is improved. Thus, it has been confirmed that harmful substances in exhaust gas are greatly reduced. On the other hand, in the proposed exhaust gas purification device, the dust particles in the exhaust gas are efficiently removed by the cylindrical metal net filter, and the decomposition of harmful chemical substances proceeds by the far infrared rays emitted from the far infrared ceramics. Is known.

  The object of the present invention is further developed from the various purification methods proposed above, and can significantly reduce harmful substances in the exhaust gas of an internal combustion engine. An object of the present invention is to provide an exhaust gas purifying apparatus that can sufficiently cope with both economical aspects.

If means for achieving the above object is shown with reference numerals in the drawings, the invention of claim 1 is a horizontal cylinder having a bellows structure peripheral wall 3a in an exhaust gas passage 2 of an internal combustion engine (diesel engine 1). interposed the Jo exhaust gas reaction chamber 3, in an exhaust gas purification device of the injection means (ammonia injection unit 5) an internal combustion engine comprising providing a for injecting the ammonia and water vapor in the exhaust gas flowing into the exhaust gas reaction chamber 3 .

  According to a second aspect of the present invention, there is provided an ammonia injection device 5 according to the first aspect, wherein the injection means injects ammonia water into the exhaust gas in the form of a mist upstream of the exhaust gas reaction chamber 3. It is supposed to consist of

  According to a third aspect of the present invention, in the exhaust gas purifying apparatus of the second aspect, the ammonia water concentration is 8% or more and less than 10%.

According to a fourth aspect of the present invention, there is provided an exhaust gas purifying apparatus according to any one of the first to third aspects, wherein a plurality of exhaust gas purification apparatuses are provided between the side end plates 3b, 3b of the cylindrical exhaust gas reaction chamber 3 having the peripheral wall 3a of the bellows structure. 4. An exhaust gas purifying device for an internal combustion engine according to claim 3, wherein the long bolt 4 for preventing the bending is disposed so as to sandwich the exhaust gas reaction chamber 3 from the outside.

According to a fifth aspect of the present invention, in the exhaust gas purifying apparatus according to any one of the first to fourth aspects, the exhaust gas inlet 31 and the exhaust gas outlet 32 of the exhaust gas reaction chamber 3 are arranged in the center line direction in the exhaust gas reaction chamber 3. The peripheral walls 31a and 32a are porous, and the inner ends 31b and 32b are closed.
Gas purification device.

According to a sixth aspect of the present invention, in the exhaust gas purifying apparatus according to any one of the first to fifth aspects, the internal combustion engine is the diesel engine 1, and the diesel is disposed in the exhaust gas passage 2 upstream of the ammonia and water vapor injection portion. The configuration is such that a particulate filter 6 is interposed.

The invention of claim 7 is the exhaust gas purification device of claim 6, wherein the diesel particulate filter 6 is consisted of honeycomb ceramic layer carrying an oxidation catalyst.

The invention of claim 8 is the exhaust gas purifying apparatus according to any one of claims 1 to 7 , wherein a plurality of strong magnets are provided in the cylindrical casing 14a in the fuel oil supply path 13 connecting the fuel tank 12 and the internal combustion engine 1. 14b... Is arranged, and a fuel oil activation device 14 that allows fuel oil to contact and pass through these strong magnets 14b.

According to the exhaust gas purifying apparatus for an internal combustion engine according to the invention of claim 1, since ammonia and water vapor in the exhaust gas flowing into the exhaust gas reaction chamber is injected, the exhaust gas reaction chamber, the exhaust by the catalytic action of the ammonia gas The decomposition of nitrogen oxide (NO _x ) contained therein into nitrogen gas (N ₂ ) and water (H ₂ O) proceeds. Therefore, since the exhaust gas reaction chamber is in a severely disturbed state due to the large flow resistance due to the bellows structure of the peripheral wall, the decomposition reaction of nitrogen oxide proceeds more efficiently , and the nitrogen oxide in the exhaust gas finally released is reduced. Remarkably reduced. In addition, when the temperature is lowered, the groove portion of the bellows structure becomes a liquid reservoir on the lower side of the peripheral wall, and the outflow of condensed water and excess ammonia water to the outside is prevented. In addition, the bellows structure peripheral wall expands and contracts in response to exhaust gas pressure fluctuations depending on the operating status of the internal combustion engine, and expansion and contraction dimensional changes due to thermal fluctuations are also absorbed by the bellows structure peripheral wall. Damage to the chamber wall and the mounting portion of the chamber can be avoided, and further, an effect of absorbing vibration by the peripheral wall can be obtained, thereby improving the durability of the exhaust gas purification device.

  According to the invention of claim 2, the mist-like ammonia water injected on the upstream side of the exhaust gas reaction chamber is uniformly mixed with the high-temperature exhaust gas and vaporized to become ammonia gas and water vapor. Decomposition of nitrogen oxide proceeds more efficiently.

  According to the invention of claim 3, since the concentration of the ammonia water is a low concentration that is outside the scope of application of the UN, dangerous goods handling regulations, firefighting law, dramatic poisoning law, etc., there is no danger in handling. If leaked, there is no concern about serious health and environmental problems.

According to the invention of claim 4, the exhaust gas reaction chamber having the peripheral wall of the bellows structure is prevented from being bent entirely by the long bolts arranged on the outer periphery even if expansion / contraction deformation occurs due to internal pressure fluctuation or thermal fluctuation. Therefore, excellent durability can be obtained without causing damage such as rupture and cracking due to the bending deformation.

According to the invention of claim 5 , while exhaust gas is discharged radially from the cylindrical exhaust gas inlet at the center toward the periphery of the reaction chamber on the inlet side of the exhaust gas reaction chamber, In this case, since the flow is directed from the periphery to the cylindrical exhaust gas outlet, the degree of disturbance of the exhaust gas in the exhaust gas reaction chamber becomes intense, and the decomposition reaction of nitrogen oxide proceeds efficiently.

According to the invention of claim 6 , for the exhaust gas of a diesel engine, the diesel particulate filter interposed upstream of the ammonia and water vapor injection portion allows fine dust particles (PM) in the exhaust gas to be emitted. Removed.

According to the invention of claim 7 , since the diesel particulate filter is composed of a honeycomb ceramic layer carrying an oxidation catalyst, in addition to the filter action, oxidative decomposition of carbon and hydrocarbons and carbon monoxide (CO) by catalytic activity. As a result, the fine dust particles (PM) in the exhaust gas are further reduced, and the hydrocarbons and carbon monoxide are also significantly reduced.

According to the invention of claim 8, since the fuel oil sent to the internal combustion engine is activated by magnetism and the combustion efficiency in the internal combustion engine is improved, harmful substances in the exhaust gas at the stage of leaving the internal combustion engine The amount of harmful substances in the exhaust gas that is finally exhausted is reduced accordingly.

  Hereinafter, an embodiment in which an exhaust gas purification apparatus of the present invention is applied to exhaust gas purification of a truck diesel engine will be described in detail with reference to the drawings.

  1 and 2, E is a diesel engine of the truck T, 1 is an exhaust gas passage from the engine E, 2 is a diesel particulate filter (hereinafter referred to as DPF) interposed upstream of the exhaust gas passage 1, 3 is an exhaust gas reaction chamber interposed downstream of the exhaust gas passage 1, 4 is a bellows tube interposed between the DPF 2 and the exhaust gas reaction chamber 3, and 5 is an exhaust gas between the DPF 2 and the bellows tube 4. An ammonia injection device for injecting ammonia water into the passage 1 in the form of a mist, 6 is a fuel tank, 7 is a fuel oil supply path connecting the fuel tank 6 and the diesel engine E, and 8 is interposed in the fuel oil supply path 7. A fuel oil activation device. In FIG. 2, A is an accelerator pedal, C is an ammonia injection controller, and P is an ammonia injection pump.

  The DPF 2 is formed by loading a honeycomb ceramic layer 21 carrying an oxidation catalyst such as platinum (Pt) in a cylindrical casing 20 in the form of a muffler (silencer). The honeycomb ceramic layers 21 are arranged such that the pores of the honeycomb are alternately cut off on the opposite side.

  The exhaust gas reaction chamber 3 is made of stainless steel and, as shown in detail in FIGS. 3A and 3B, has a horizontal cylindrical shape with a peripheral wall 3a having a bellows structure. Further, the exhaust gas inlet 31 and the exhaust gas outlet 32 communicating with the exhaust gas passage 1 of the exhaust gas reaction chamber 3 are configured in a short cylinder shape that enters the exhaust gas reaction chamber 3 along the direction of the center line, and the peripheral wall 31a. , 32a is made of a perforated metal and the tips 31b, 32b are closed. Further, on both side end plates 3b, 3c of the exhaust gas reaction chamber 3, projecting pieces 30 are formed equally at three places in the circumferential direction, and the projecting pieces 30, 30 opposed to the both side end plates 3b, 3c, respectively. In the middle, long bolts 33 are fastened via nuts 34 so as to sandwich the outer periphery of the exhaust gas reaction chamber 3 from three directions.

  The ammonia injection device 5 sends the ammonia water stored in the tank 51 to the nozzle 52 through the pump P, and injects it into the exhaust gas pipe 11 between the DPF 2 and the bellows tube 4 in the form of a mist from the nozzle 52. It is like that. Thus, the ammonia injection controller C increases or decreases the discharge amount of the pump P according to the rotational speed of the diesel engine E, and when the depression amount of the accelerator pedal A becomes zero or a predetermined value or less, The discharge is stopped or throttled. Further, when the amount of ammonia water in the tank 51 decreases to a specified value, this is detected by the liquid level sensor 53, and the alarm 54 provided in the driver's seat is activated by the detection signal, and the operation is performed by a buzzer, sound or light emission. To inform the person.

  According to the exhaust gas purification apparatus having the above configuration, the exhaust gas discharged from the diesel engine E to the exhaust gas passage 1 is first purified in the process of passing through the DPF 2 and then the ammonia water supplied from the ammonia injection device 5. Vaporized gas (ammonia and water vapor) is mixed, flows into the exhaust gas reaction chamber 3 through the bellows tube 4, is purified by the reaction here, and then continues to the exhaust port (not shown). 12 is discharged from the exhaust port to the outside. At the stage of being discharged from the exhaust port, harmful gas components such as nitrogen oxides (NOx), hydrocarbons (HC), and carbon monoxide (CO) are extremely small, and minute dust particles (PM) are greatly reduced. As a result, the exhaust smoke density is low.

In the primary purification using the DPF 2 described above, filtration and removal of solid particles such as PM and soot, oxidative decomposition of carbon components (C) and hydrocarbons (HC), and oxidation of carbon monoxide by catalytic activity. Is done. The oxidation reaction is shown below. In addition, since the original fine dust particles are 3 μm or less, they cannot be removed by a normal air cleaner that generally removes solid particles up to about 8 μm.
(1) Carbon: C + O ₂ → CO ₂ (carbon dioxide)
(2) Hydrocarbon: HC + O ₂ → H ₂ O (steam), CO ₂
(3) Carbon monoxide: 2CO + O ₂ → 2CO ₂

The secondary purification in the exhaust gas reaction chamber 3 is decomposition of nitrogen oxide (NOx) contained in the exhaust gas into nitrogen gas and water by reaction with ammonia. That is, ammonia has a reducing action, and nitrogen gas (N ₂ ) and water vapor (H ₂ O) are deprived of oxygen from nitrogen monoxide (NO) and nitrogen dioxide (NO ₂ ) in the exhaust gas by the following reaction. ) Is generated.
(4) 2NO + 2NH ₄ OH → 2N ₂ + 4H ₂ O + H ₂
(5) 4NO ₂ + 4NH ₄ OH → 4N ₂ + 10H ₂ O + O ₂
(6) 2H ₂ + O ₂ → 2H ₂ O

As the aqueous ammonia used, one having a concentration of 8% or more and less than 10% is suitable. In the case of a low concentration of less than 10%, there is no danger in handling, as it is not covered by the UN, Dangerous Goods Handling Regulations, Fire Service Law, Violent Poison Law, etc. This is because there is no concern about serious environmental problems. However, if the concentration of ammonia water is less than 8%, it will not be possible to fully exhibit the NO _x decomposition action described later. Therefore, the concentration is set to 8% or more. 9% is recommended.

  Thus, in the exhaust gas reaction chamber 3, in addition to causing a large flow resistance by the peripheral wall 3a of the bellows structure, the inner ends of the exhaust gas inlet 31 and the exhaust gas outlet 32 that have entered into a short cylinder shape are blocked. Since the gas enters and exits from the porous peripheral walls 31a and 32a, the exhaust gas is discharged radially from the center toward the periphery on the inlet side, and flows from the periphery toward the center on the outlet side. A linear flow to the outlet 32 is not generated, and the inside becomes a severely disturbed state, and the decomposition reaction of the nitrogen oxide is promoted. Therefore, even if the total length of the exhaust gas reaction chamber 3 is short, a high NOx reduction effect can be obtained.

  Further, since the exhaust gas reaction chamber 3 has a horizontal cylindrical shape with a peripheral wall 3a having a bellows structure, when the temperature is lowered, the bellows groove portion at the bottom of the inner surface becomes a liquid reservoir, so that condensed water and excess ammonia water do not flow out to the outside. Stored. The stored portion is vaporized as the next temperature rises, ammonia is reacted and consumed, and condensed water is discharged as water vapor along with the exhaust gas.

  The exhaust gas emission amount increases or decreases in proportion to the engine speed. The engine speed is detected by a speed sensor (not shown), and the ammonia injection controller C injects ammonia water based on the detection signal. Since the amount is increased or decreased stepwise or continuously in accordance with the engine speed, high and low NOx efficiency is stably maintained without causing excess or deficiency in the amount of ammonia water injected due to fluctuations in the exhaust amount. Incidentally, if the relationship between the engine speed of the truck diesel engine E and the preferred injection amount of 9% ammonia water is shown as an example, the standard for each engine displacement is as shown in Table 1 below.

  Therefore, for example, under a situation where the load on the engine E is small, such as a downhill running state on a slope or an idling state while waiting for traffic lights or traffic jams, the amount of NOx contained in the exhaust gas is reduced. Uses the fact that the driver releases his foot from the accelerator pedal A or relaxes the depression, and when the depression amount of the accelerator pedal A is zero or below a predetermined value, it is detected by an accelerator switch (not shown), and the detection Based on the signal, the controller C stops or reduces the injection of the ammonia water. Therefore, there is no concern that ammonia water is excessively injected under the condition of a small load on the engine E and is discharged in an unreacted state and mixed with exhaust gas.

  On the other hand, the exhaust gas emission amount varies depending on the operating condition of the diesel engine E, and thus the pressure in the exhaust gas reaction chamber 3 varies greatly. In this embodiment, the peripheral wall 3a of the bellows structure expands and contracts in response to the pressure variation. Deform. In addition, a large temperature difference is generated in the exhaust gas reaction chamber 3 when the engine is stopped and when the engine is operating. The expansion / contraction dimensional change due to the temperature fluctuation is also absorbed by the peripheral wall 3a of the bellows structure. Moreover, even if the peripheral wall 3a is expanded or contracted due to the fluctuation of the pressure or temperature in this way, the entire exhaust gas reaction chamber 3 is prevented from being bent and deformed by the long bolts 33 arranged on the outer periphery. Therefore, in this embodiment, rupture and cracking of the wall of the exhaust gas reaction chamber 3 due to fluctuations in the pressure and temperature and damage to the mounting portion are avoided, and excellent durability is obtained.

  The bellows tube 4 interposed upstream of the exhaust gas reaction chamber 3 utilizes the elasticity of the peripheral wall of the bellows structure similar to that of the exhaust gas reaction chamber 3, and absorbs vibrations due to engine operation and running, pressure and temperature. It functions to absorb the expansion and contraction of the entire exhaust gas passage 1 due to the fluctuation of the above, and thereby to improve the durability of the entire pipeline. Of course, also in the exhaust gas reaction chamber 3, there is a vibration absorbing action by the peripheral wall 3a of the bellows structure.

  By the way, although the primary purification and the secondary purification itself are exerted without any problem even if the processing order is reversed, the temperature of the exhaust gas is lowered to some extent by the injection of ammonia water, but due to the catalytic activity in the DPF2. Since a high temperature is desirable for the oxidation reaction, a configuration in which ammonia water is injected downstream of the DPF 2 as in this embodiment is recommended. Further, it is preferable that the exhaust gas passage 1 from the engine E to the outlet of the DPF 2 is wrapped with a heat insulating material such as glass wool and the outer periphery thereof is covered with an aluminum foil or the like to keep the temperature. Thus, for example, when the exhaust gas temperature is about 480 ° C. when leaving the diesel engine E, the temperature is about 350 to 400 ° C. at the outlet of the DPF 2 and about 230 ° C. at the outlet of the exhaust gas reaction chamber 3 due to the heat retention. .

  As shown in FIG. 4, the fuel oil activation device 8 interposed in the fuel oil supply path 7 has a fixed shaft 82 extending through the cylindrical case 81 along the center line, and the fixed shaft 82 is anisotropic. A large number of strong magnet plates 83 made of ferrite or the like are fixed at regular intervals. These strong magnet plates 83 are each provided with a shape obtained by cutting a substantially square corner portion into an arc shape, and are fixed to the fixed shaft 82 in such a manner that its circumferential direction changes little by little. Accordingly, the position of the flow gap formed between the four sides of the square and the inner peripheral surface of the case 81 is set so as to sequentially change in the case axial direction. Reference numeral 84 denotes a holding plate that holds the fixed shaft 25 at an important point in the case 24, and has a shape in which a circular part is cut off as a flow gap, and is integrated with the case 81.

  Thus, in the fuel oil activation device 8, the light oil supplied from the fuel tank 6 flows in from the inlet 8 a provided at one end of the cylindrical case 81, and each strong magnet plate 83 and the inner peripheral surface of the case 81 In the process of sequentially passing between the two and reaching the outlet 8b, it is activated by receiving a strong magnetic force action by the strong magnet plates 83. Therefore, the combustion efficiency in the diesel engine E is improved, the fuel consumption is reduced, and the harmful substances in the exhaust gas at the stage of exiting from the engine E are reduced. Less.

  The exhaust gas purifying apparatus of the present invention includes a configuration in which one or both of the fuel oil activating apparatus and the DPF as used in the embodiment are omitted. In particular, the exhaust gas purifying apparatus can effectively reduce fine dust particles (PM). The use of DPF is recommended. Thus, as the DPF, commercially available products having various structures can be used, and among them, those having catalytic activity as used in the above-described embodiment are preferable, but those having a high PM reduction ability only by the filter function are preferable. Can be used for In the configuration in which the oxidation catalyst is supported on the ceramic as in the DPF 2 used in the above embodiment, the catalytic activity is enhanced by the far-infrared effect radiated from the ceramic. For example, the engine speed decreases due to traffic congestion on the road. A high PM reduction rate can be achieved even when the exhaust gas temperature is low.

While in the previous SL embodiment are arranged bellows tube 4 for stretching and vibration absorption on the upstream side of the exhaust gas reaction chamber 3, depending on the installation condition of DPF2 and exhaust gas reaction chamber 3, such bellows tube 4 It can be omitted. In addition, the detailed configuration of the exhaust gas purifying apparatus of the present invention can be variously modified in addition to the embodiment. Moreover, although the diesel engine which uses light oil as a fuel was illustrated as an internal combustion engine in the said embodiment, the exhaust-gas purification apparatus of this invention is applicable similarly to various internal combustion engines other than a diesel engine.

  Next, an embodiment of exhaust gas purification of an automobile diesel engine by the exhaust gas purification device of the present invention will be described in comparison with a comparative example in which the exhaust gas purification device is not used.

Comparative Example 1 / Example 1
The following automobile A is used, and in Comparative Example 1, the exhaust gas purification device is not installed, but in the 13 operation modes shown in Table 2, and in Example 1, the exhaust gas purification device having the device configuration shown in FIG. In each of the 13 operation modes shown in Fig. 1, the test is performed to measure the diluted exhaust gas component concentration (CO, HC, NO _x , CO ₂ ), dilution rate, diluted exhaust gas amount, gas exhaust amount per hour, and total PM exhaust amount. did. The results are shown in Table 3 for Comparative Example 1 and Table 5 for Example 1. The details of the test contents and the configuration of the purification device are as follows.

[Car A]
Car name / model: Hino Diesel Truck U-FD3HLAK
Number of mileage: 490379 km (Comparative Example 1), 490311 km (Example 1) Total vehicle weight: 5530 kg
Engine model: H07D (4 cycle-6 cylinder)
Total displacement: 7.412L

〔contents of the test〕
Testing organization: Japan Vehicle Inspection Association Automobile Testing Laboratory Test date: December 2, 2003 Test item:
(1) Diesel vehicle 13 mode exhaust gas test with chassis dynamometer (2) Diesel exhaust smoke concentration test (free accelerator mode)
Fuel used: Low sulfur gas oil

[Purification device configuration]
DPF: SONETEX-RN41 (platinum-supporting honeycomb ceramic type DPF) manufactured by Dinax A / S
Ammonia injection device: Tank ... Made of SUS304-Capacity 50L, Pump ... Maximum discharge amount 450ml / min, Ammonia water concentration 9%, Injection amount ... Based on Table 1 Exhaust gas reaction chamber: MB0001 made by Makita Transportation Co., Ltd. (with the structure of FIG. 3) All made of SUS304) Reaction chamber ... Overall length 500mm, outer diameter 200mm
Outlet inlet: inside diameter 77 mm, reaction chamber entry length 200 mm, peripheral wall with 150 holes with a diameter of 5 mm (15 rows in the circumferential direction, 10 rows in the radial direction)
Fuel oil activation device: Futures manufactured by Makita Transportation Co., Ltd.

Comparative Example 2 and Example 2
The following automobile B was used, and in Comparative Example 2, the exhaust gas purification device was not installed, but in the 13 operation modes shown in Table 6, and in Example 2, the exhaust gas purification device having the device configuration shown in FIG. Each of the 13 operation modes shown in Fig. 1 was tested to measure the diluted exhaust gas component concentration, dilution rate, diluted exhaust gas amount, gas exhaust amount per hour, and total PM exhaust amount. The results are shown in Table 7 for Comparative Example 2 and Table 9 for Example 2. The details of the purification device configuration are the same as those in the first embodiment.

[Car B]
Car name / model: Nissan Diesel Truck KC-MK211HH
Number of mileage: 166275 km (Comparative Example 2), 166132 km (Example 2) Total vehicle weight: 7990 kg
Engine model: FE6 (4 cycle-6 cylinder)
Total displacement: 6.925L

〔contents of the test〕
Testing organization: Japan Vehicle Inspection Association Automobile Testing Laboratory Test Date: October 16, 2003 Test Items:
(1) Diesel vehicle 13 mode exhaust gas test with chassis dynamometer (2) Diesel exhaust smoke concentration test (free accelerator mode)
Fuel used: Low sulfur gas oil

Example 3
About the automobile B used in Comparative Example 2 and Example 2, an actual running durability test of 30,000 km including a highway and a general road was performed in the Kyushu region while operating the same exhaust gas purifying device as that of Example 2 in operation. As a result, no abnormality of the purification device or damage to the attachment site was observed during the running period. Then, after this actual running durability test, a test similar to Comparative Example 2 and Example 2 was conducted at the Japan Vehicle Inspection Association Car Testing Laboratory (Test Date: November 28, 2003). Table 13 shows the 13 operation modes, and Table 11 shows the test results.

  Table 12 shows the average emissions of exhaust gas components and PM, the reduction rate (%), and the amount of black smoke emitted by the present invention in the tests of Comparative Examples 1 and 2 and Examples 1 to 3. The average emission amount is a value obtained by dividing the total emission amount of each component by the total work amount.

As shown in Table 12, when the exhaust gas purifying apparatus of the present invention is used, the case where there is no purifying apparatus (Comparative Example 1,) after the actual running durability test of 30,000 km (Example 3). Compared to 2), nitrogen oxides (NO _x ) in the exhaust gas have an extremely high reduction rate of 80% or more and fine dust particles (PM) of 85% or more. Furthermore, carbon monoxide (CO) and Black smoke is about 100% and hydrocarbon (HC) is about 50%. Therefore, according to the exhaust gas purification apparatus of the present invention, it can be seen that harmful components in the exhaust gas can be effectively reduced.

Example 4
The following automobile C is used, and the exhaust gas purification device having the device configuration shown in FIG. 2 is mounted, and the test is performed in the 13 operation modes shown in Table 13, and the diluted exhaust gas component concentrations (CO, HC, NO _x , CO ₂ ) The dilution rate, the amount of diluted exhaust gas, and the amount of gas discharged per hour were measured. The results are shown in Table 14. Details of the test contents and the purification device configuration are as follows.

[Car C]
Car name / model: Mitsubishi Diesel Truck P-FU415N modified Traveling distance: 81284 km
Total vehicle weight: 19715kg
Engine model: 8DC9 (4 cycle-8V cylinder)
Total displacement: 16.0L

〔contents of the test〕
Test organization: Japan Automobile Research Institute Test date: July 5, 2004 Test item: Diesel vehicle 13-mode exhaust gas test with chassis dynamometer Fuel used: Low sulfur gas oil

[Purification device configuration]
DPF: SONETEX-RN43 (platinum-supporting honeycomb ceramic type DPF) manufactured by Dinax A / S
Ammonia injection device: tank ... made of SUS304-capacity 98L, pump ... maximum discharge amount 450ml / min, used ammonia water concentration 9%, injection amount ... based on Table 1 Exhaust gas reaction chamber: Makita Transport Co., Ltd. MB0004 (with structure of FIG. 3) All made of SUS304) Reaction chamber ... Overall length 500mm, outer diameter 300mm
Outlet inlet: inside diameter 77 mm, reaction chamber entry length 200 mm, peripheral wall with 150 holes with a diameter of 5 mm (15 rows in the circumferential direction, 10 rows in the radial direction)
Fuel oil activation device: Futures manufactured by Makita Transportation Co., Ltd.

Example 5
The following automobile D is used, and the exhaust gas purifying apparatus having the apparatus configuration shown in FIG. 2 is mounted and tested in the 13 operation modes shown in Table 15, and diluted exhaust gas component concentrations (CO, HC, NO _x , CO ₂ ) The dilution rate, the amount of diluted exhaust gas, and the amount of gas discharged per hour were measured. The results are shown in Table 16. The details of the test including the date and the details of the purification device configuration are the same as those in the fourth embodiment.

[Car D]
Car name / model: Isuzu Diesel truck P-CXM19P modified Travel distance: 152 115km
Total vehicle weight: 19975kg
Engine model: 10PC1 (4 cycle-10V cylinder)
Total displacement: 15.0L

Table 17 below shows the average emission amount of exhaust gas components in the tests of Examples 4 and 5 above. From Table 17, it can be seen that even in a large diesel truck having a gross vehicle weight of nearly 20 tons, the use of the exhaust gas purification apparatus of the present invention can significantly reduce harmful components such as NOx and PM in the exhaust gas. .

Example 6
About the automobile B used in Example 2 and the automobile D used in Example 4, the same exhaust gas purifying device as that of Example 2 and Example 4 was mounted and operated, and the road between Ashiya and Takarazuka on National Route 2 was 57 km. The operator who was on the platform throughout the entire section of the vehicle continuously controlled the ammonia concentration in the exhaust gas discharged from the exhaust port using the semiconductor manufacturing gas detector (XD303 ammonia manufactured by New Cosmo Electric Co., Ltd.). Measured. However, this section is a course with a lot of ascending and descending through the Arima Hot Spring at an altitude of about 600m, and there were 46 stops at the Ashiya side and 21 times at the Takarazuka side in the middle, but the exhaust gas The ammonia concentration was 0.1 ppm or less throughout the vehicle B and 0 ppm throughout the vehicle D (outside the measurement limit) regardless of the engine load. From this result, the exhaust gas purifying apparatus of the present invention uses ammonia water as the treatment agent, but the ammonia water is mixed with the exhaust gas and released even under a situation in which the load on the engine E varies greatly and frequently occurs. It can be seen that there is no concern.

1 is a schematic side view of a truck equipped with an exhaust gas purification device for an internal combustion engine according to an embodiment of the present invention. It is a schematic block diagram of the same exhaust gas purification device. The exhaust gas reaction chamber of the exhaust gas purification apparatus is shown, (A) is a front view, and (B) is a cross-sectional view taken along line BB in (A). It is a vertical side view of the fuel oil activation device used for the exhaust gas purification device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exhaust gas passage 2 Diesel particulate filter 3 Exhaust gas reaction chamber 3a Circumferential wall part 31 Exhaust gas inlet 31a Perimeter wall 31b Inner end 32 Exhaust gas outlet 32a Peripheral wall 32b Inner end 33 Long bolt 5 Ammonia injection device 51 Ammonia water tank 6 Fuel tank 7 Fuel oil Supply path 8 Fuel oil activation device 81 Cylindrical casing 83 Strong magnet A Accelerator pedal C Controller for ammonia injection E Diesel engine P Pump for ammonia injection

Claims (8)

An internal combustion engine in which an exhaust gas passage of an internal combustion engine is provided with a horizontal cylindrical exhaust gas reaction chamber having a bellows-shaped peripheral wall, and injection means for injecting ammonia and water vapor into the exhaust gas flowing into the exhaust gas reaction chamber is provided. Engine exhaust gas purification device.   2. An exhaust gas purification apparatus for an internal combustion engine according to claim 1, wherein said injection means comprises an ammonia injection device for injecting ammonia water into the exhaust gas in the form of a mist on the upstream side of the exhaust gas reaction chamber.   The exhaust gas purification apparatus for an internal combustion engine according to claim 2, wherein the concentration of the ammonia water is 8% or more and less than 10%. A plurality of bending-preventing long bolts are disposed between both side end plates of the cylindrical exhaust gas reaction chamber having the peripheral wall of the bellows structure so as to sandwich the exhaust gas reaction chamber from the outside . The exhaust gas purification apparatus for an internal combustion engine according to any one of the above. An exhaust gas inlet and an exhaust gas outlet of the exhaust gas reaction chamber are formed in a short cylindrical shape that enters the exhaust gas reaction chamber along the center line direction, and the peripheral wall forms a porous shape and the inner end is closed. The exhaust gas purification apparatus for an internal combustion engine according to any one of claims 1 to 4 . The exhaust gas purifying device for an internal combustion engine according to any one of 1 to 5 , wherein the internal combustion engine is a diesel engine, and a diesel particulate filter is interposed in an exhaust gas passage upstream of the ammonia and water vapor injection portion. The exhaust gas purifying device for an internal combustion engine according to claim 6, wherein the diesel particulate filter is composed of a honeycomb ceramic layer carrying an oxidation catalyst. A fuel oil supply path connecting the fuel tank and the internal combustion engine is provided with a plurality of strong magnets arranged in a cylindrical casing, and a fuel oil activation device for passing the fuel oil in contact with the strong magnets is interposed. The exhaust gas purification apparatus for an internal combustion engine according to any one of claims 1 to 7 .

Images