JP6045471B2 - PM generation method and PM generation apparatus - Google Patents

Description

  The present invention relates to a means for generating particulate matter (PM) in a gas in order to evaluate an exhaust gas purification device provided with a DPF, a catalyst, and the like.

Particulates and harmful substances in exhaust gas discharged from various internal combustion engines and the like have a great influence on the human body and the environment, and there is an increasing need to prevent their release into the atmosphere. In particular, particulate matter (Particulate Matter (PM)), nitrogen oxides (NO _x ) and the like discharged from diesel engines have a great influence, and regulations concerning them are being strengthened worldwide.

Under such circumstances, research and development of exhaust gas purification equipment equipped with a catalyst (Particulate Filter (PF)) for removing PM and a catalyst useful for reducing NO _X to nitrogen and water, etc., has proceeded. Currently, high-performance purifiers are being offered to the market. PF includes DPF for diesel engines and GPF for gasoline engines.

  However, the present situation is that no means has been proposed for testing the exhaust gas purification device and evaluating the performance and durability with high accuracy. Also, there are not many prior literatures related to such technology.

  In order to break down such a current situation, the applicant of the present application has previously developed and disclosed a technique according to Patent Documents 1 to 5. Accordingly, in order to evaluate the exhaust gas purification device, it is possible to stably supply exhaust gas that sufficiently simulates exhaust gas discharged from an actual engine or the like. In addition, Patent Document 6 and Non-Patent Document 1 can be cited as other prior art documents.

JP 2007-155712 A JP 2007-155708 A JP 2010-223877 A JP 2011-196909 A JP 2012-117520 A JP-A-2005-214742

ETH Conference on Nanoparticle Measurement 18-20 August 2003, CAST SOOT GENERATOR FOR LIQUID FUEL, L. JING

  However, in some actual exhaust gases, PM forms a specific particle size distribution depending on the conditions of the engine or the like that discharges the exhaust gas. Therefore, in order to test the performance and durability of an exhaust gas purification device against the exhaust gas of a certain engine and evaluate it with high accuracy, it is necessary that PM supply exhaust gas having a desired particle size distribution. There is a case.

  For example, in a certain diesel engine and a certain direct-injection gasoline engine, it has been found that there is one peak in a particle size as small as about 20 nm in the particle size distribution of PM in the discharged gas. This is greatly different from the particle size distribution disclosed in FIG. 7 of Patent Document 3 and having one peak around 80 to 90 nm. Further, in FIG. 9j of Patent Document 5, a peak is formed at a small particle diameter, but it is a double peak, and there is a peak around 80 to 90 nm. That is, in the means disclosed in the prior art document, it has not been possible to form a main peak in a small particle size (for example, around 20 nm) in the particle size distribution of PM in exhaust gas containing PM. .

  The present invention has been made in view of the above-described circumstances, and its problem is exhaust gas for evaluation to be supplied to an exhaust gas purification device, where PM has a desired (specific) particle size distribution. In particular, it is to provide a suitable means for producing and supplying exhaust gas containing PM having a particle size distribution with one peak at a small particle size. As a result of repeated research, when the flame of a combustion gas with a methane content of 90% by volume or more is quenched with air, the particle size distribution of PM with a small particle size (near 20 nm) as one main peak is obtained. The knowledge that it is obtained was acquired. In addition, by creating a plurality of methane gas combustion devices and light oil intermittent injection combustion devices and overlapping the particle size distribution of the PM produced by them, it is possible to approximate the various PM particle size distributions of an actual engine. As a result, the present invention has been completed. Specifically, the above problems can be solved by the following means.

  That is, first, according to the present invention, the combustion gas having a methane content of 90 volume (vol)% or more is continuously supplied into the combustion air, specifying the excess air ratio λ, There is provided a PM generation method for generating particulate matter (PM) having a specific particle size distribution in gas (gas A) after being ignited and burned and then cooled.

  In the PM generation method according to the present invention, the methane content in the combustion gas is preferably 95 vol% or more. The combustion gas means a gas that burns, and does not include a gas that does not burn, such as an inert gas. Combustion gas with methane content of 90 vol% or more means that methane occupies 90 vol% or more of the combustion gas, and other than methane (0 to 10%) is also a combustible substance (gas). Means. For example, a gas in which methane is 90 vol% and the remainder is an inert gas such as nitrogen gas can be used in the PM generation method according to the present invention. In this case, methane is 100 vol% as a combustion gas. is there. A preferred combustion gas with a methane content of 90 vol% or more is natural gas. There are many natural gases having a methane content of 90 vol% or more depending on the production area, which can be suitably used.

PM generating method according to the present invention, the specific particle size distribution is needed use when it is that there is substantially one peak in the particle size between: 10 to 20 nm. The meaning of substantially one peak is that the distribution peak is not divided into two or more.

In the PM generating method according to the present invention, the above (according to the gas A) excess air ratio, Ru der 0.80 to 1.05. In the PM generation method according to the present invention, it is particularly preferable that the excess air ratio (related to gas A) is 0.87 or in the vicinity thereof.

  In the PM generation method according to the present invention, the cooling is preferably performed with air.

  Next, according to the present invention, light oil is intermittently injected into the gas A in which PM is generated by any one of the above-described PM generation methods and the combustion air by specifying the excess air ratio λ. , After burning at a temperature of 750 ° C. or more and 1050 ° C. or less, cooling and mixing with a gas (gas B) that generates PM having a specific particle size distribution, and in the gas, A mixed PM generation method for generating PM having a specific particle size distribution is provided.

  The mixed PM generation method according to the present invention is suitably used when the specific particle size distribution applied to the gas B has a peak in particle size between 80 and 100 nm.

  In the mixed PM generation method according to the present invention, it is preferable that an excess air ratio applied to the gas B is 0.70 to 1.25. In the mixed PM generation method according to the present invention, it is particularly preferable that the excess air ratio applied to the gas B is 1.10 to 1.20 or close to the range.

  In the mixed PM generation method according to the present invention, the gas B is preferably plural. This means that, for example, gas B is composed of gas B1, gas B2,.

  The PM generation method and the mixed PM generation method according to the present invention are methods for generating PM in a gas, in other words, a method for manufacturing and supplying a gas that generates PM (PM-containing gas). I can do it.

  Next, according to the present invention, in any PM generation method or mixed PM generation method described above, a PM generation device used for the gas A, the air inlet for supplying combustion air, and Combustion chamber having a gas outlet for discharging the gas that has generated PM, combustion gas having a methane content of 90 vol% or more is internally burned, and is inserted into the combustion chamber; A main burner that continuously supplies combustion gas with a methane content of 90 vol% or more into the combustion chamber, and a combustion gas that is attached to the combustion chamber and has a methane content of 90 vol% or more supplied to the combustion chamber. There is provided a PM generator (referred to as PM generator A) including a pilot burner that ignites.

  In the PM generator A according to the present invention, the main burner has one supply hole for supplying combustion gas with a methane content of 90 vol% or more, and the opening diameter of the supply hole is 4 to 10 mm. It is preferable.

  In PM generator A concerning the present invention, it is preferred that the opening direction of a supply hole is the side to which combustion air is supplied.

  In the PM generator A according to the present invention, a substantially L-shaped tube is connected to the air inlet of the combustion chamber, and combustion air is supplied to the combustion chamber via the substantially L-shaped tube. Is preferred.

  Next, according to the present invention, in any one of the mixed PM generation methods described above, the PM generator is used for the gas B, and generates an air inlet and PM for supplying combustion air. It has a gas outlet for discharging the gas, and it is possible to inject light oil intermittently into the combustion chamber in which light oil is burned and PM is generated, and the combustion air supplied to the combustion chamber There is provided a PM generator (referred to as PM generator B) provided with such a light oil intermittent injection means and a pilot burner attached to the combustion chamber and igniting the light oil supplied to the combustion chamber.

  Next, according to the present invention, any one of the PM generators A described above, and a sample storage container for storing a filter, which is an evaluation sample, disposed on the gas outlet side of the PM generator A, There is provided a filter evaluation device that sends PM generated by the PM generator A together with gas to a sample storage container, and supplies the PM-containing gas to a filter stored in the sample storage container. Typical examples of the filter include a porous ceramic structure and a honeycomb structure. More specific examples are DPF and GPF.

  In the filter evaluation apparatus according to the present invention, a collecting pipe is provided between any of the PM generating apparatuses A and the sample storage container, and one or more PM generating apparatuses B are included in the collecting pipe ( It is preferable that one or a plurality of units are connected. In addition, a sample storage container is connected to the (gas) outlet side of the collecting tube, and one or more (one or more) PM generators A are connected to the (gas) inlet side of the collecting tube. One PM generator B may be connected, or two or more (plural) of the PM generators A are connected to the (gas) inlet side of the collecting pipe, and two PM generators B are connected. The above (plural groups) may be connected. As the collecting pipe, for example, a pipe having a flange attached to a cylindrical pipe called a header pipe can be adopted. The collecting pipe desirably has a sufficient residence space for mixing the gas A and the gas B. Further, the inside of the collecting pipe may be empty, but it is also preferable to pack a filler so that the gas can be easily mixed.

  According to the PM generation method of the present invention, a combustion gas with a methane content of 90 vol% or more is used, and its continuous supply, ignition, combustion, and cooling are performed to reduce the particle size to about 20 nm. Exhaust gas (gas A) containing PM having a particle size distribution with two peaks can be produced and supplied. That is, it is possible to realize a PM particle size distribution of an actual engine (or an approximation thereof) that could not be achieved by the prior art disclosed in the prior art document. Therefore, depending on the conditions of the engine or the like, it is possible to cope with such a specific particle size distribution that there is one peak in such a small particle size of about 20 nm, and the performance and durability of the exhaust gas purification device against exhaust gas can be improved. It is possible to test and evaluate with high accuracy. Specifically, it becomes possible to easily evaluate the SOF content removal performance of the oxidation catalyst DOC and the PM collection performance of the DPF carrying the oxidation catalyst.

  In the mixed PM generation method according to the present invention, light oil is intermittently injected into combustion air at a temperature of 750 ° C. or higher and 1050 ° C. or lower with an excess air ratio λ specified. Later, by cooling, it is possible to produce and supply exhaust gas (gas B) containing PM having a particle size distribution with a peak in the particle size of about 80 to 100 nm. And by mixing the gas A and the gas B, it is possible to approximate the particle size distribution of PM in the exhaust gas exhausted from the actual engine, and in the performance and durability test of the exhaust gas purification device The accuracy and precision are further improved.

1 is a side view schematically showing an embodiment of a PM generator (PM generator A) according to the present invention and a filter evaluation apparatus according to the present invention. 1 is a side view schematically showing an embodiment of a PM generator (PM generator B) according to the present invention. It is a figure which shows the result of the reference example 1, and is a graph showing the particle size distribution of PM in the exhaust gas of a motor vehicle. It is a figure which shows the result of the reference example 2, and is a graph showing the particle size distribution of PM in the exhaust gas of a motor vehicle. It is a figure which shows the result of the reference examples 1, 3, and 4, and is a graph showing the particle size distribution of PM in the exhaust gas of a motor vehicle. It is a figure which shows the result of Example 1, 2, 3 and is a graph showing the particle size distribution of PM in PM containing gas. It is a figure which shows the result of Example 4 and the reference example 2, and is a graph showing the particle size distribution of PM in PM containing gas. It is a side view which shows typically other embodiment of the filter evaluation apparatus which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate, but the present invention should not be construed as being limited thereto. Various changes, modifications, improvements, and substitutions can be added based on the knowledge of those skilled in the art without departing from the scope of the present invention. For example, the drawings show preferred embodiments of the present invention, but the present invention is not limited by the modes shown in the drawings or the information shown in the drawings. In practicing or verifying the present invention, the same means as described in this specification or equivalent means can be applied, but preferred means are those described below.

  First, an embodiment of a PM generator A according to the present invention and a filter evaluation apparatus according to the present invention including the PM generator A will be described with reference to FIG. The filter evaluation apparatus 200 according to the present invention includes a PM generator 100 (PM generator A) according to the present invention and a sample storage container 31, which are connected by a rectifying pipe 35. The sample storage container 31 is disposed on the gas outlet 2 side of the PM generator 100 and stores a filter 32 that is an evaluation sample. The PM generated by the PM generator 100 is sent to the sample storage container 31 together with the gas, and is supplied to the filter 32 stored in the sample storage container 31.

  The PM generator 100 includes a combustion chamber 3 having an air inlet 1 for supplying combustion air F1 and a gas outlet 2 for discharging burned gas, and a cylindrical main burner 4 inserted into the combustion chamber 3. , A pilot burner 6 attached to the combustion chamber 3, an elbow pipe 36 (substantially L-shaped pipe) connected to the air inlet 1, a combustion air flow rate control means 43 for controlling the flow rate of the combustion air F1, and cooling air introduction A cooling air mixing pipe 34 provided with a nozzle 33 on the side surface, an air supply means 41, and a cooling air flow rate control means 42 for controlling the flow rate of the cooling air F3 supplied from the air supply means 41 are provided.

  In the PM generator 100, the shape of the combustion chamber 3 is a cylindrical shape in which both end portions are formed to be tapered. The size of the combustion chamber 3 is not particularly limited, and, for example, natural gas (combustion gas with a methane content of 90 vol% or more) is combusted by the necessary range of combustion air F1 to generate PM. Any size is possible.

  In the PM generator 100, the position at which the main burner 4 is disposed is 100 mm from the position at which the pilot burner 6 is disposed toward the downstream side, and 200 mm from the position at which the pilot burner 6 is disposed toward the upstream side. Within the range up to the position of. The main burner 4 has one supply hole (not shown) for supplying natural gas. The opening diameter of the supply hole is 4 to 10 mm, and the particularly preferable opening diameter is 6 mm. The opening of the supply hole is on the side to which combustion air is supplied. That is, the opening direction of the supply hole is not upstream but upstream. This means that it is substantially opposed to the flow of combustion air. Furthermore, the cylindrical main burner 4 in which the supply hole is formed is inserted into the combustion chamber 3 from the side surface of the combustion chamber 3 so that the central axis thereof is orthogonal to the direction in which the combustion air F1 flows.

  In the PM generator 100, the elbow pipe 36 is connected to the air inlet 1 of the combustion chamber 3 and is substantially L-shaped, so that when the combustion air F1 is supplied into the combustion chamber 3, Drift. The elbow pipe 36 (substantially L-shaped pipe) is not indispensable, but if it is provided, PM is likely to be generated due to the drift caused by it.

  Specific examples of the air supply means 41 include supply of air by a compressor, supply of air by a blower, and the like. Specific examples of the combustion air flow rate control means 43 and the cooling air flow rate control means 42 include a pressure reducing valve and a flow rate control valve.

  Next, the PM generator B according to the present invention used in the mixed PM generating method according to the present invention will be described with reference to FIG. A main component of the PM generator 300 (PM generator B) according to the present invention is a combustion chamber 103. The shape of the combustion chamber 103 is a cylindrical shape with a short axial length in which one end portion is formed in a tapered shape. The size of the combustion chamber 103 is not particularly limited as long as it is a size capable of burning light oil (fuel) and generating PM by the necessary range of combustion air F11.

  In the PM generator 300, a nozzle is provided in the combustion chamber 103, which serves as an air inlet 11 for supplying combustion air F11. Further, the portion formed in a tapered shape is a gas outlet 12 for discharging the burned gas. In the vicinity of the air inlet 11 of the combustion chamber 103, there is provided light oil intermittent injection means 14 capable of intermittently injecting light oil into the combustion air F11. A specific example is an electronic or electromagnetic injector. A flow meter 144 is provided in a light oil supply system (not shown) connected to the light oil intermittent injection means 14. And in the cylindrical combustion chamber 103, the pilot burner 16 which ignites light oil is attached to the non-tapered side.

  The PM generator 300 further includes a combustion air flow rate control means 143 for controlling the flow rate of the combustion air F11, a cooling air mixing pipe 134 provided with a cooling air introduction nozzle 133 on its side surface, an air supply means 141, and its air supply means. The cooling air flow rate control means 142 which controls the flow volume of the cooling air F13 supplied from 141 is provided.

  Specific examples of the air supply unit 141 include supply of air by a compressor, supply of air by a blower, and the like. Specific examples of the combustion air flow rate control unit 143 and the cooling air flow rate control unit 142 include a pressure reducing valve and a flow rate control valve.

  Next, another embodiment of the filter evaluation apparatus according to the present invention will be described with reference to FIG. A filter evaluation apparatus 500 according to the present invention includes a PM generator 100 (PM generator A) according to the present invention and two PM generators 300 (PM generator B) according to the present invention. The generators 100 and 300 are connected to the collecting pipe 501 by rectifying pipes 35 and 135, and the collecting pipe 501 is connected to the sample storage container 31. In other words, the filter evaluation apparatus 500 includes the collecting pipe 501 in the filter evaluation apparatus 200 before the rectifying pipe 35 (on the PM generation apparatus 100 side) between the PM generation apparatus 100 and the sample storage container 31. It can be said that two PM generators 300 are connected to the collecting pipe 501. In the form shown in FIG. 7, the PM generator 100 and the two PM generators 300 are connected to the collecting pipe 501 from three directions, but the rectifying pipes 35 and 135 are brought close to each other so that the collecting pipe 501 is identical. You may connect to the surface.

  Since the PM generators 100 and 300 and the sample storage container 31 in the filter evaluation apparatus 500 are as described above, they are omitted here. In the filter evaluation apparatus 500, the air supply means 41 is shared, and serves as an air source for the combustion air F1, F11 and cooling air F3, F13, and also as an air source for the secondary air F53. The filter evaluation apparatus 500 further includes secondary air flow rate control means 541 that controls the flow rate of the secondary air F53 supplied from the air supply means 41. Specific examples of the secondary air flow rate control means 541 include a pressure reducing valve and a flow rate control valve.

  Next, the PM generation method according to the present invention will be described by taking the case of using the PM generation device 100 as an example. First, the air supply means 41 is operated, the combustion air F1 is continuously supplied from the air inlet 1 to the combustion chamber 3, and the cooling air F3 is continuously supplied to the cooling air mixing pipe. At the same time, natural gas is continuously supplied from the main burner 4. Then, natural gas is ignited by the pilot burner 6 and burned. Then, the combusted gas is discharged from the gas outlet 2, cooled by the cooling air F3, and PM is generated so as to have a particle size distribution having approximately one peak in the particle size between 10 and 20 nm. The gas contains PM (PM-containing gas) F2.

In the PM generating method according to the present invention, the PM generator 100, so that the excess air ratio is 0.80 to 1.05, that to supply combustion air from the air inlet 1. The excess air ratio is particularly preferably in the vicinity of 0.87.

  In general, the excess air ratio is a ratio indicating how far the actual air-fuel ratio is away from the theoretical value, and is expressed as (amount of supplied (combustion) air) / (theoretical necessary ( For combustion). The excess air ratio referred to in this specification is an average excess air ratio in the combustion chamber. The flow rate (volume) of the entire combustion air flowing through the combustion chamber and the flow rate (volume) of the entire fuel (combustion gas) being supplied. And is calculated using

  In the PM generation method according to the present invention, in the PM generator 100, the average flow velocity of the combustion air F1 (in the combustion chamber 3) is preferably 0.1 to 4.0 m / sec. It is especially preferable that it is 0.1-2.0 m / sec. If it is faster than 4.0 m / sec, the amount of PM generated may be reduced.

  Next, the mixed PM generation method according to the present invention will be described using the filter evaluation apparatus 500 as an example. The filter evaluation apparatus 500 includes one PM generator 100 and two PM generators 300. However, when implementing the mixed PM generation method according to the present invention, one PM generation device 100 and three or more PM generation devices 300 may be used, and two or more PM generation devices 100 and 1 may be used. The basic PM generator 300 may be used, or two or more PM generators 100 and two or more PM generators 300 may be used. Further, when the mixed PM generation method according to the present invention is performed, the air supply means can be shared by the PM generation apparatuses 100 and 300 as in the filter evaluation apparatus 500 described above.

  Since the use of the PM generator 100 is the same as that when used alone (PM generation method according to the present invention), the description thereof is omitted here. Below, the usage method of the said PM generator 300 is demonstrated. First, the air supply means 141 is operated, the combustion air F11 is continuously supplied from the air inlet 11 to the combustion chamber 103, and the cooling air F13 is continuously supplied to the cooling air mixing tube 134. In addition, the light oil is intermittently injected from the light oil intermittent injection means 14. Then, light oil is ignited by the pilot burner 16 and burned at a temperature of 750 ° C. or higher and 1050 ° C. or lower. Then, the combusted gas is discharged from the gas outlet 12, cooled by the cooling air F13, and PM is generated so that the particle size distribution has a peak in the particle size of 80 to 100 nm, and the gas containing PM. (PM-containing gas) F12.

  In the mixed PM generation method according to the present invention, it is desirable for the PM generator 300 to specify an excess air ratio of 0.70 to 1.25. In other words, combustion air is supplied from the air inlet 11 so that the excess air ratio is 0.70 to 1.25.

  When the filter evaluation device 500 is used, the role of PM generation by the PM generator 300 is to modify the particle size distribution of the PM generated by the PM generator 100 and to reduce the particle size of PM discharged from the actual vehicle. To be close to the distribution. Therefore, the amount of PM to be generated by the PM generator 100 is based on the amount of PM generated by the PM generator 100 in order to approach the target particle size distribution of PM (distribution of the actual vehicle). Determined. And the flow volume of the combustion air F11 in PM generator 100, the injection quantity of light oil, and the intermittent injection number (frequency) are decided. In the mixed PM generation method according to the present invention, the particle size distribution of the PM generated by the PM generator 300 in the PM generator 100 based on the particle size distribution of the PM generated by the PM generator 300. It may have a role of modifying. Such a mixing method may be effective depending on the particle size distribution of PM discharged from an actual vehicle.

  Next, the use of the filter evaluation apparatus according to the present invention will be described by taking the case of using the filter evaluation apparatus 200 as an example. Since PM can be generated by the PM generator 100 as described above, if the PM-containing gas F2 is sent to the sample storage container 31 and supplied to the filter 32 stored in the sample storage container 31, the filter For 32, it is possible to effectively perform a test performed by collecting PM. By this test, it is possible to obtain a result close to that in a case where it is mounted on an automobile or the like.

  In the use of the filter evaluation apparatus 500 according to the present invention, when the filter evaluation apparatus 500 is used, PM can be generated by the PM generators 100 and 300 as described above. They are sent to the collecting pipe 501, mixed with each other, and the mixed gas is sent to the sample storage container 31 and supplied to the filter 32 stored in the sample storage container 31. Then, the filter 32 can be effectively tested by collecting PM. By this test, it is possible to obtain a result close to that in a case where it is mounted on an automobile or the like. In particular, when the filter evaluation device 500 is used, as described above, the PM-containing gas F2 having a PM particle size distribution having approximately one peak in the particle size of 10 to 20 nm is obtained by using the PM generator 100. By using the PM generator 300, the PM-containing gas F12 having a PM particle size distribution with a peak in the particle size of 80 to 100 nm is obtained. In the two PM generators 300, the peak of the PM particle diameter can be changed in the range of 80 to 100 nm. The PM-containing gas F2 and the two PM-containing gases F12 can be adjusted in flow rate by the combustion air flow rate control means 43, 143 and the cooling air flow rate control means 42, 142, respectively. The mixing ratio of F2, PM-containing gas F12 (part 1), and PM-containing gas F12 (part 2) can be freely adjusted. Therefore, it is possible to finely adjust the particle size distribution of PM, and it can be made closer to the particle size distribution of PM in the exhaust gas actually discharged from the engine. In addition, by adjusting the flow rate of the secondary air F53 to be further mixed with the mixed gas at the inlet of the sample storage container 31, the PM concentration can be changed without changing the desired PM particle size distribution. Is also possible.

  Next, a method for manufacturing a PM generator and a filter evaluation apparatus according to the present invention will be described by taking as an example a case where a filter evaluation apparatus 500 including the PM generators 100 and 300 is manufactured. The PM generator 100 can be manufactured using known processing means based on the above description, the shape shown in FIGS. 1 and 7, and the disclosure of Patent Document 4. Preferable materials for the combustion chamber 3, the main burner 4, and the elbow pipe 36 are stainless steel, nickel alloy and the like, and preferable materials for the pilot burner 6 are stainless steel, carbon steel and the like. The PM generator 300 is manufactured using known processing means based on the above description, the shape shown in FIGS. 2 and 7, and the disclosure of Patent Documents 1 to 3 and 5 (especially Patent Document 2). I can do it. Preferred materials for the combustion chamber 103 are nickel alloys (particularly Inconel: trademark), ceramics (particularly silicon nitride), etc., and preferred materials for the pilot burner 16 are stainless steel, carbon steel, and the like. The sample storage container 31 can be manufactured using known processing means based on the above description, the shape shown in FIGS. 1 and 7, and the disclosure of Patent Document 4, and a preferable material thereof is stainless steel. Such as steel. The rectifying pipes 35 and 135, the cooling air introduction nozzles 33 and 133, and the cooling air mixing pipes 34 and 134 can be manufactured using known processing means based on the above description and the shape shown in FIG. The preferred material is stainless steel, nickel alloy or the like. As described above, after obtaining the respective components, the filter evaluation apparatus 500 can be obtained by performing connection and assembly based on the above-described description and the configuration shown in FIG. .

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

(Reference Example 1) A 2.0-liter (euro 4 compliant) diesel engine vehicle (actual vehicle, Sporta made by Kia Motors) equipped with DOC (front stage, oxidation catalyst) and DPF (back stage) was compliant with PMP. The engine was operated in NEDC mode, and exhaust gas was collected on the inlet side of the DOC. The target was the exhaust gas, and the particle size distribution of PM was measured using a model number 3091 (FMPS) manufactured by TSI as a particle size distribution measuring device. The results are shown in FIG. 3A and FIG. In figures, tables, specifications, etc., a conventional display for computers may be used as an index display. For example, 1.0 × 10 ⁵ is represented as 1.0E + 5, and both are 100,000.

  (Reference Example 2) A 1.4 L gasoline engine vehicle (GOLF made by Volkswagen) equipped with GPF was operated in NEDC mode in accordance with PMP, and exhaust gas was collected at the DPF inlet side. In the same manner as in Reference Example 1, the particle size distribution of PM was measured. The results are shown in FIG. 3B and FIG.

  (Consideration 1) From FIGS. 3A and 3B, it can be seen that the particle size distribution of PM in the gas discharged from the automobile has one peak at a small particle size of about 20 nm. Moreover, when FIG. 3A is seen, the bulge of a small mountain can be confirmed in the large particle diameter side (right side in FIG. 3A).

  The PM concentration is the number of PM per unit volume. PMP is an abbreviation for a particle measurement program by the Emissions Energy Experts Conference (abbreviated as GRPE) of the World Forum for Harmonization of Automotive Standards (abbreviated as WP29) in the European Economic Committee (abbreviated as ECE) of the United Nations (abbreviated as UN). . The NEDC mode is an operation mode of a diesel engine vehicle in the PN measurement method by PMP, and is an abbreviation for New European Driving Cycle mode. The NEDC mode includes a preconditioning period, a soaking period, and a measurement (measurement) period.

  (Reference Example 3) As a soluble organic component (SOF) removal device, a Dekati thermodenuder (model TD3) was used, and after removing SOF of the collected exhaust gas, the particle size of PM Distribution was measured. The rest is the same as Reference Example 1. The results are shown in FIG.

  Reference Example 4 Exhaust gas was sampled on the DPF inlet side (DOC outlet side), and the particle size distribution of PM was measured. The rest is the same as Reference Example 1. The results are shown in FIG.

  (Consideration 2) FIG. 4 shows that when the SOF is removed, the particle size distribution of the PM changes greatly, so that the gas discharged from the automobile contains a large amount of SOF. The small peak bulge on the large particle size side (the right side in FIG. 3A) is a component other than SOF.

  (Example 1) A filter evaluation apparatus 200 including a PM generator 100 having a structure as shown in FIG. 1 was produced mainly using stainless steel having a thickness of 9 mm as a material. The length of the combustion chamber 3 in the gas flow direction is 900 mm, the inner diameter (diameter) of the air inlet 1 (see FIG. 1) is 70 mm, the inner diameter of the gas outlet 2 (see FIG. 1) is 106 mm, The inner diameter (diameter) of the central parallel portion (portion not tapered) was 130 mm. The combustion chamber 3 has a structure in which the air inlet 1 side and the air outlet 2 side are formed in a tapered shape, and the length of the tapered portion in the gas flow direction is set to 100 mm. The length of the cooling air mixing pipe 34 in the gas flow direction was 450 mm, and the inner diameter was the same as the inner diameter of the gas outlet 2 of the combustion chamber 3. The cooling air supply nozzle 33 disposed in the cooling air mixing tube 34 has an inner diameter (diameter) of 106 mm. The cooling air mixing tube 34 and the cooling air supply nozzle 33 were cylindrical. The sample storage container 31 was cylindrical with an inner diameter (diameter) of 313 mm and a length of 360 mm. As the air supply means, a compressor was used, and air was pressurized to generate cooling air. A pressure reducing valve and a flow rate control valve were used as the cooling air flow rate control means. Air (cooling air) generated by the air supply means was used as combustion air and cooling air. The main burner 4 was cylindrical with a diameter (inner diameter) of 10.5 mm, and one supply hole with a diameter of 6 mm was formed. The main burner 4 was arranged so that the supply hole was located at the center of the combustion chamber 3 in a cross section orthogonal to the gas flow direction. The opening of the supply hole was directed to the air inlet 1 side (upstream side). The main burner 4 was arranged at a position of 50 mm from the position of the pilot burner 6 toward the downstream side in the gas flow direction. The pilot burner 6 can be automatically ignited, compressed air can be used, and a flame detector can be attached. The pilot burner 6 was installed on the wall surface of the combustion chamber 3 so as to be orthogonal to the gas flow direction. The pilot burner 6 was disposed at a position 400 mm from the air inlet 1 in the gas flow direction of the combustion chamber 3. For details of other PM generators 100, see Patent Document 4.

  Using such a filter evaluation apparatus 200, PM was generated (PM-containing gas was produced). The natural gas used has a methane content of about 95 vol%. The flow rate of natural gas was 41 Nl / min, and the combustion air was supplied at 0.35 Nm3 / min. The total amount of the mixed gas after adding cooling air was 7.11 Nm3 / min. The excess air ratio in the combustion chamber 3 was 0.87. The pilot burner 6 was extinguished 20 seconds after the main burner 4 was ignited. And PM containing gas was extract | collected at the entrance side of the sample storage container 31, and the particle size distribution of PM was measured similarly to the reference example 1. FIG. The results are shown in FIG.

  (Consideration 3) From the result of FIG. 1 (FIG. 5), according to the PM generator 100 (filter evaluation apparatus 200), the particle size distribution of PM in the gas is approximately one peak between 10 and 20 nm. It can be seen that there can be something. In other words, the PM generator 100 can produce a gas containing PM having a particle size distribution with approximately one peak between 10 and 20 nm. However, compared with Reference Example 1 (FIG. 3A), the PM concentration on the large particle size side is small (there is no small mountain bulge).

  (Example 2) A PM generator 300 having a structure as shown in FIG. 2 was prepared using an Inconel material, and PM was generated using the PM generator 300 (PM-containing gas was manufactured). ). Refer to Patent Document 2 for details of the PM generator 300.

  US diesel oil (Ultra Low Sulfur Diesel, sulfur component of 15 ppm or less) is used as diesel oil, and it is used in an amount of 1.98 liters / hour, and combustion air is used so that the excess air ratio is 1.13. Supplied. Further, the light oil injection pressure by the light oil intermittent injection means 14 provided in the PM generator 300 is 0.25 Mpa, the valve opening time (light oil injection time) is 1.3 milliseconds, and the valve opening period (light oil injection period) is 51. .3 milliseconds. In addition, the temperature in the wall of the combustion chamber 103 of the PM generator 300 is preliminarily burned with propane gas fuel and combustion air, and the temperature is raised to 350 to 400 ° C. Light oil was injected using the light oil intermittent injection means 14 (electromagnetic injector), burned, and further heated to 800 ° C. or higher. And PM containing gas was extract | collected and the particle size distribution of PM was measured similarly to the reference example 1. FIG. The results are shown in FIG.

  (Example 3) Separately from Example 2, PM was generated using the PM generator 300 shown in FIG. 2 (PM-containing gas was produced). The operating conditions are as follows: the amount of light oil used is 1.23 liters / hour, the excess air ratio is 1.19, the light oil injection pressure is 0.25 Mpa, the valve opening time (light oil injection time) is 4.5 milliseconds, The valve cycle (light oil injection cycle) is 54.5 milliseconds, and the rest is the same as in Example 2. And PM containing gas was extract | collected and the particle size distribution of PM was measured similarly to the reference example 1. FIG. The results are shown in FIG.

  (Example 4) A PM-containing gas was generated by the mixed PM generation method according to the present invention, and the particle size distribution of PM therein was determined. Specifically, a filter evaluation apparatus 500 including the PM generators 100 and 300 having a structure as shown in FIG. 7 is manufactured, and one of the PM generators 100 is used by using the filter evaluation apparatus 500. In the same manner as in Example 1, PM was generated (a PM-containing gas was produced), and the two PM generators 300 were each generated in the same manner as in Examples 2 and 3 (PM Containing gas). And PM containing gas mixed with the collecting pipe 501 was extract | collected, and the particle size distribution of PM was measured similarly to the reference example 1. FIG. The results are shown in FIG. Note that the mixing ratio (volume ratio) of the PM-containing gas produced by the PM generator 100 and the two PM generators 300 is all equally divided.

  (Consideration 4) As can be seen from a comparison between Example 1 (FIG. 5) and Example 4 (FIG. 6), in Example 4, the PM concentration on the larger particle size side is larger than that in Example 1. . That is, according to the mixed PM generation method according to the present invention, it can be more closely approximated to the particle size distribution of PM in the exhaust gas discharged from the actual engine (Reference Example 2: FIG. 3B). .

  The PM generation method and the PM generation apparatus according to the present invention have the performance and durability of an exhaust gas purification device including a filter for removing particulates in exhaust gas and a catalyst for decomposing harmful substances in exhaust gas. It is preferably used for evaluation.

DESCRIPTION OF SYMBOLS 1,11: Air inlet 2, 12: Gas outlet 3,103: Combustion chamber 4: Main burner 6, 16: Pilot burner 14: Light oil intermittent injection means 31: Sample storage container 32: Filter 33, 133: Cooling air introduction nozzle 34, 134: Cooling air mixing pipe 35, 135: Rectifier pipe 36: Elbow pipe 41, 141: Air supply means 42, 142: Cooling air flow rate control means 43, 143: Combustion air flow rate control means 100, 300: PM generation Device 144: Flowmeter 200, 500: Filter evaluation device 501: Collecting pipe 541: Secondary air flow rate control means F1, F11: Combustion air F2, F12: Gas containing PM (PM-containing gas)
F3, F13: Cooling air F53: Secondary air

Claims (14)

In the combustion air, a combustion gas having a methane content of 90% by volume or more is continuously supplied with an excess air ratio λ of 0.80 to 1.05 , ignited and burned. After that, the PM generating method of cooling and generating particulate matter (PM) having a particle size distribution having approximately one peak in the particle size of 10 to 20 nm in the gas A. The cooling is, PM generating method of claim 1 carried out in air. Gas A generated by the PM generation method according to claim 1 or 2 , and
Light oil is injected into the combustion air intermittently with the excess air ratio λ specified, burned at a temperature of 750 ° C. or higher and 1050 ° C. or lower, and then cooled to obtain a specific particle size distribution. Gas B that generates PM
A mixed PM generation method in which PM having a specific particle size distribution is generated in a gas. The mixed PM generation method according to claim 3 , wherein the specific particle size distribution applied to the gas B has a peak in a particle size of 80 to 100 nm. The mixed PM generation method according to claim 3 or 4 , wherein an excess air ratio of the gas B is 0.70 to 1.25. The mixed PM generation method according to claim 5 , wherein an excess air ratio of the gas B is 1.10 to 1.20. The mixed PM generation method according to any one of claims 3 to 6 , wherein the gas B is plural. The PM generation method according to claim 1 or 2 , or the mixed PM generation method according to any one of claims 3 to 7 , wherein the PM generation device is used for the gas A,
Combustion gas having an air inlet for supplying combustion air and a gas outlet for discharging the gas that generated PM, and having a methane content of 90% by volume or more is burned inside, and PM is A combustion chamber,
A main burner inserted into the combustion chamber and continuously supplying a combustion gas having a methane content of 90% by volume or more into the combustion chamber;
A pilot burner attached to the combustion chamber and igniting a combustion gas having a content of the methane supplied to the combustion chamber of 90% by volume or more;
PM generator comprising: The PM generation according to claim 8 , wherein the main burner has one supply hole for supplying combustion gas with the methane content of 90% by volume or more, and the opening diameter of the supply hole is 4 to 10 mm. apparatus. The PM generator according to claim 8 or 9 , wherein an opening direction of the supply hole is a side to which the combustion air is supplied. To the air inlet of the combustion chamber, it is connected to a substantially L-shaped tube, through the tube of substantially L-shaped, one of claims 8 to 10, wherein combustion air is supplied to the combustion chamber The PM generator according to one item. The mixed PM generation method according to any one of claims 3 to 7 , wherein the PM generator is used for the gas B,
A combustion chamber that has an air inlet for supplying combustion air and a gas outlet for discharging the gas that has generated PM, and in which PM is generated by burning the light oil therein;
A light oil intermittent injection means capable of intermittently injecting the light oil into the combustion air supplied to the combustion chamber;
A pilot burner attached to the combustion chamber and igniting the light oil supplied to the combustion chamber;
PM generator comprising: A PM storage device according to any one of claims 8 to 11 , and a sample storage container for storing a filter, which is an evaluation sample, disposed on the gas outlet side of the PM generation device,
A filter evaluation device that sends PM generated by the PM generator together with gas to the sample storage container, and supplies the gas containing the PM to a filter stored in the sample storage container. A PM pipe is provided between the PM generator according to any one of claims 8 to 11 and the sample storage container, and the PM generator according to claim 12 is provided in the pipe. The filter evaluation apparatus according to claim 13 , wherein one or more are connected.

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