JP6139942B2 - Filter evaluation method - Google Patents

Description

  The present invention relates to a means for evaluating a filter that removes particulate matter (referred to herein as a particulate filter (PF), also simply referred to as a filter). More specifically, the present invention relates to a particle measurement program (abbreviated as GRPE) of the Emissions Energy Expert Meeting (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) It relates to means for evaluating DPF (diesel particulate filter) by means of PN measurement, which can be substituted for the PN measurement method proposed by PMP). The invention also relates to means for evaluating a GPF (gasoline particulate filter).

  Fine particles in exhaust gas discharged from various internal combustion engines or the like have a great influence on the human body and the environment. Therefore, there is an increasing need to prevent these releases to the atmosphere. In particular, PM (particulate matter, particulate matter) discharged from a diesel engine has the above-mentioned influence, and PM regulations are being strengthened worldwide.

  In Europe, where the majority of automobile engines are diesel engines, PM contained in exhaust gas is not only regulated by weight (mass) in the conventional way in the exhaust gas regulations by the European Union (abbreviated EU). It was determined that it was also regulated by the number of particles (number). Since September 2012, regulations based on PN (particle number, number of particles) have been introduced from the new Euro 5+ regulations. This is because measurement of the weight (mass) of PM is said to be at the limit of the current level, and if it becomes too small, there may be a problem of accuracy, and it is large on the order of nanometers (nm). This is because the PM has a great influence on the lungs of the human body.

  As prior art documents, Patent Document 1 and Non-Patent Documents 1 and 2 have been announced.

JP 2012-117520 A

Japan Society of Automotive Engineers, Preprint of Academic Lecture, No. 118-08, Development of particulate measurement technology in automobile exhaust gas Japan Society of Automotive Engineers, Preprint of Academic Lecture, No. 155-07, Investigation of soot particle discharge behavior by solid particle number measurement system

  By the way, for example, diesel engine cars can comply with PM regulations largely by DPF in post-processing technology. Diesel engine vehicles that can be equipped with DPF can also comply with the new PN regulations, and whether or not diesel engine cars can meet the new PN regulations depends on the development and evaluation of the DPF. It is no exaggeration to say.

  In Europe, the PN measurement method using PMP adopts a NEDC (New European Driving Cycle) mode as a driving mode of a diesel engine vehicle. The NEDC mode includes a preconditioning period, a soaking period, and a measurement (measurement) period. EUDC (Extra Urban Driving Cyde) in the preconditioning period (see FIG. 8A) and the measurement period (see FIG. 8B) is a high-speed operation mode including up to 130 km / h, and ECE15 (ECE rules in the measurement period). No.) is a repeated urban driving mode determined by the ECE. The problem here is that the soaking period is 6 hours or more. For this reason, for example, if an attempt is made to evaluate the PN removal capability of a newly developed DPF based on a PN measurement method using PMP, it takes approximately 7 hours per NEDC mode. With this, the development of DPF does not progress slowly.

  The present invention has been made in view of such circumstances, and its problem is to obtain a PN measuring means correlated with a PN measuring method based on Euro 5+ regulations, thereby meeting European regulations. Thus, an object of the present invention is to provide a means for evaluating a DPF appropriately, in a short time, accurately and accurately. As a result of repeated research, it has been found that this problem can be solved by the following means.

That is, according to the present invention, the gas that has generated particulate matter using the PM generator is supplied to the measurement filter, and the number of the particulate matter in the gas before passing through the measurement filter and the gas that has passed through the measurement filter. And dividing the number of particulate matter in the gas passed by the number of particulate matter in the gas before passing through to obtain the number ratio of particulate matter in the measurement filter, and the obtained particulate matter A process B for estimating the number of particulate matter per unit mileage of exhaust gas discharged from an actual vehicle equipped with a measurement filter based on the number ratio of the matter, and a particulate matter using a PM generator Is supplied to the standard filter, and the number of each particulate matter in the gas before passing through the standard filter and the gas passed through is obtained. The number C of the particulate matter in the gas before passing through is divided by the number C of the particulate matter in the gas before passing through the process C for obtaining the number ratio of the particulate matter in the standard filter, and discharged from an actual vehicle equipped with the standard filter. A process D for measuring the number of particulate matter per unit mileage of the exhaust gas, and performing the processes C and D for a plurality of standard filters, and the number ratio of the particulate matter obtained in the process C; Based on the approximate expression obtained from the relationship between the number of the particulate matter per unit travel distance obtained in the process D and the number of the particulate matter per unit travel distance estimated for the measurement filter in the process B, A method for evaluating a compensating filter is provided.

  In the filter evaluation method according to the present invention, it is preferable that the number of the plurality of standard filters performing the process C and the process D (when the above correction is performed) is 3 or more.

  In the filter evaluation method according to the present invention, the number ratio of the particulate matter in the measurement filter in the process A is the maximum value of the number ratio of the particulate matter in the standard filter in the process C (when the above correction is performed). The plurality of standard filters are preferably selected so as to be smaller and larger than the minimum value. This means that it is preferable that the correction is performed by interpolation or by interpolation. In the filter evaluation method according to the present invention, the above correction may be extrapolated (may be performed by extrapolation).

  In the filter evaluation method according to the present invention, the PM generating device mixes fuel and fuel combustion air and causes combustion of the mixed fuel mixture, and the fuel combustion chamber. Provided with a fuel injection means capable of intermittently injecting the fuel and a fuel pilot burner for igniting the fuel mixture, and incomplete combustion of the fuel mixture, It is preferable to generate particulate matter in the inside.

  In the filter evaluation method according to the present invention, in the PM generator, the fuel is injected into the fuel combustion air, the excess air ratio λ is specified, intermittently injected, burned, and in the gas. It is preferable to generate a particulate material having a specific particle size distribution.

  In the filter evaluation method according to the present invention, light oil or propane gas can be used as the fuel. A more preferred fuel is light oil.

  In the filter evaluation method according to the present invention, a gas in which particulate matter is generated using a PM generator is supplied to a measurement filter, and the particulate matter in the gas before passing through the measurement filter and in the passed gas. The process A for determining the number ratio of the particulate matter in the measurement filter by dividing the number of the particulate matter in the gas passed through by the number of the particulate matter in the gas before passing, and the obtained And a process B for estimating the number of particulate matter per unit mileage of exhaust gas exhausted from an actual vehicle equipped with a measurement filter based on the number ratio of particulate matter. The PN removal capability of the filter can be evaluated. Therefore, the development of filters (DPF, GPF) is promoted, and as a result, the amount of PM released into the atmosphere of automobiles and the like is reduced, contributing to environmental improvement.

Evaluation method of a filter according to the present invention supplies the gas generated particulate matter using P M generator standard filter, each of the particulate in the gas and passing the gas before passing through the standard filter Obtaining the number of substances, dividing the number of particulate substances in the gas passed through by the number of particulate substances in the gas before passing through, and obtaining the number ratio of the particulate substances in the standard filter; A process D for measuring the number of particulate matter per unit mileage of exhaust gas discharged from an actual vehicle mounted, and performing processes C and D for a plurality of standard filters. Based on the approximate expression obtained from the relationship between the obtained number ratio of the particulate matter and the number of the particulate matter per unit mileage obtained in the process D, Since the number of particulate matter per unit mileage applied to the measurement filter estimated in step B is compensated, the exhaust gas discharged from the actual vehicle equipped with the measurement filter is more accurate and accurate than otherwise. The number of particulate matter per unit travel distance can be estimated.

  In the filter evaluation method according to the present invention, the number of the plurality of standard filters performing the process C and the process D is 3 or more (when the above correction is performed). It is possible to estimate the number of particulate matter per unit mileage of exhaust gas discharged from an actual vehicle equipped with a filter.

  In the filter evaluation method according to the present invention, preferably, the above-described correction is performed by interpolation (because it is performed by interpolation), and therefore, more accurately and accurately than when performed by extrapolation (extrapolation), It is possible to estimate the number of particulate matter per unit mileage of exhaust gas exhausted from an actual vehicle equipped with a measurement filter.

  According to the filter evaluation method of the present invention, in the above PM generator, fuel is specified in an air for fuel combustion by intermittently injecting and combusting fuel by specifying an excess air ratio λ. It is possible to generate a particulate material having a particle size distribution of. Therefore, by adjusting the excess air ratio λ, it is possible to immediately generate a PM-containing gas having a particle size distribution equivalent to the particle size distribution of exhaust gas discharged from a diesel engine vehicle operated in the NEDC mode. Is possible. Therefore, the PM-containing gas having a particle size distribution equivalent to the particle size distribution of the exhaust gas discharged from the diesel engine vehicle operated in the NEDC mode is immediately put into the filter without taking much time as in the NEDC mode. Can be supplied. Then, the particle size distribution measuring device can measure PN (particle number, number of particles) on the inlet side of the filter (before passing through the filter) and on the outlet side of the filter (after passing through the filter). Further, the PM particle size distribution can be adjusted so as to show substantially the same distribution as the PM particle size distribution in an actual vehicle based on the PN measurement method by PMP. That is, according to the filter evaluation method of the present invention, the gas PN before passing through the DPF (filter) and after passing through the DPF (filter) under the same conditions as in the case of using the PN measuring method by PMP in a short time. Can be measured, thereby evaluating the PN removal capability of the DPF (filter). Therefore, development of DPF (filter) is promoted, and as a result, the amount of PM released into the atmosphere of automobiles and the like is reduced, contributing to environmental improvement.

  Further, according to the filter evaluation method of the present invention, the PN removal capability of the GPF (filter) can also be evaluated. Diesel engine cars and gasoline engine cars differ in light oil and gasoline, and in the amount of PM generated in exhaust gas. However, when operating in NEDC mode, the PM particle size distribution between the two is almost the same. This is because they agree.

It is a lineblock diagram showing one embodiment of a filter evaluation system concerning the present invention. It is a figure which shows one Embodiment of PM generator which comprises the filter evaluation system which concerns on this invention, and is a top view. FIG. 3 is a side view of the apparatus shown in FIG. 2. It is sectional drawing which shows PP cross section in FIG. It is sectional drawing which shows the QQ cross section in FIG. It is a perspective view which decomposes | disassembles and represents the inside of PM generator shown by FIG. It is a figure which shows the same cross section as FIG. 5, and is sectional drawing which expanded the housing | casing part and simplified and drawn the light oil injection means (fuel injection means). It is a graph which shows the preconditioning period in NEDC mode. It is a graph which shows the measurement (measurement) period in NEDC mode. It is a figure which shows the result of Examples 1-3 and Reference Example 1, and is a graph showing the particle size distribution (left vertical axis | shaft) of PM in the gas which generate | occur | produced PM. Changes in PM concentration in the PM-containing gas on the outlet side of the DPF (after processing with PDF) over time and changes in PM concentration in the PM-containing gas on the inlet side of the DPF (before processing on PDF) It is a graph which shows an example of change. It is a figure which shows the result of Example 1, and is a graph showing the correlation with PN ratio and the PN emission of the exhaust gas discharged | emitted from the diesel engine vehicle measured with the PN measuring method based on PMP. It is a figure which shows the result of Example 2, and is a graph showing the correlation with PN ratio and the PN emission of the exhaust gas discharged | emitted from the diesel engine vehicle measured by the PN measuring method based on PMP. It is a figure which shows the result of Example 3, and is a graph showing the correlation with PN ratio and the PN emission of the exhaust gas discharged | emitted from the diesel engine vehicle measured by the PN measuring method based on PMP. It is a figure which shows the result of Example 4, and is a graph showing the relationship between the area of PN ratio, and the correlation coefficient of PN ratio and (measured) PN emission.

  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.

  Since the present invention is a filter evaluation method, first, a filter evaluation system used in the filter evaluation method will be described with reference to an embodiment thereof. The filter evaluation system 100 includes a PM generator 10 and a storage chamber 90 that stores a PF (for example, DPF or GPF) (see FIG. 1). The PM generator 10 and the storage chamber 90 are connected by a pipe 97, and the outlet side (right side in FIG. 1) of the storage chamber 90 is also configured by the pipe 97. The gas generated by the PM generator 10 (flows in the direction indicated by the arrow in FIG. 1) is supplied to the storage chamber 90 in which PF is stored (to the PF therein) during use. Is discharged from the system. A pipe 97 between the PM generator 10 and the storage chamber 90 is provided with a blow valve 144 (three-way valve). By operating this blow valve 144, when the gas that has generated the PM output from the PM generator 10 is unstable (for example, at the beginning of startup), the gas is not sent to the storage chamber 90. , It can be discharged out of the system of the filter evaluation system. Further, even when the gas is stable, it is possible to replace the PF stored in the storage chamber 90 without stopping the PM generator 10.

  Respective sample systems 95, 96 are provided on the inlet side (left side in FIG. 1) and the outlet side (right side in FIG. 1) of the storage chamber 90. The sample systems 95, 96 include a diluter for diluting gas. 91 and 92 are provided, and are connected to the particle size distribution measuring devices 93 and 94 through them. Part of the PM-containing gas on the inlet side and outlet side of the storage chamber 90 (PF) (sample gas) is appropriately diluted by the diluters 91 and 92 and then supplied to the particle size distribution measuring devices 93 and 94. Then, the particle size distribution of PM in each gas is measured. That is, according to the filter evaluation system 100, the number of particles for each particle size of PM in the PM-containing gas itself before being treated with PF, and the size of each particle size of PM in the PM-containing gas after being treated with PF. It is possible to measure the number of particles. In addition, in this specification, although the gas after processing by PF may also be called PM containing gas, PM is removed substantially by PM removal capability of PF. The particle size distribution measuring devices 93 and 94 are devices based on the principle of classifying PM by electric mobility and measuring the particle size distribution based on the quantity of electricity of the classified PM.

As a particle size distribution measuring apparatus for measuring the particle size distribution of PM in gas based on the electric quantity of the classified PM by classifying PM by electric mobility, specifically, TPS's EPS (Engine Exhaust Particle Sizer) is used. Spectrometer, model 3090), FMPS (Fast Mobility Particle) from TSI
Examples include Sizer Spectrometer (model 3091), FPS (Fast Particle Sizer, models DMS500, DMS500MkII) manufactured by Cambusion. The principle of these particle size distribution devices is that the PM is charged (charged), classified according to the difference in the electric mobility of the PM, and the electric quantity (charge quantity) of the classified PM.
Is measured with an electrometer to determine the PN and concentration distribution of the classified particle size range.

  The PM generator 10 constituting the filter evaluation system 100 includes a light oil injection means 3 (fuel injection means) that intermittently injects light oil 131 (fuel) and a combustion chamber 1 (fuel combustion chamber) that generates combustion. (See FIGS. 2 to 7). The PM generator 10 continuously supplies light oil combustion air 132 (fuel combustion air) from the air inlet 113 to the combustion chamber 1 and intermittently supplies the light oil 131 by the light oil injection means 3 to the combustion chamber 1. The gas oil mixture (fuel mixture) is generated by injecting the gas oil into the combustion chamber 1, and the gas oil mixture is burned from the side (outside) in contact with the gas oil combustion air in the combustion chamber 1. The gas oil on the side that is not in contact with the gas (inner side) is cut off from the light oil combustion air, becomes a steamed state by the heat of combustion, and generates PM in the exhaust gas. That is, the PM generator 10 is an apparatus capable of producing a gas that generates PM (PM-containing gas 133).

  In the light oil injection means 3 of the PM generator 10, the injection direction (see FIG. 7) of the light oil 131 injected by itself is approximately perpendicular to the central axis direction (lateral direction in FIG. 6) of the cylindrical outer cylinder portion 6. And provided in the housing 5 so as to be inclined in a tangential direction of a cross section (circular or annular) perpendicular to the central axis direction of the outer cylinder 6 (see FIGS. 5 and 7). As the light oil injection means 3, for example, an electromagnetic injector capable of intermittently injecting light oil 131 into the space 101 between the casing 5 and the outer cylinder 6 is employed.

  The combustion chamber 1 of the PM generator 10 is divided into two at a dividing surface 53 and can be opened inside, and an outer cylinder housed in a cylindrical portion 5a of the casing 5 A ring 4 that holds the part 6, the inner cylinder part 7, and the outer cylinder part 6 is provided. The outer cylindrical portion 6 has a cylindrical shape, is incorporated in the cylindrical portion 5a of the casing portion 5 so as to be coaxial with the cylindrical portion 5a of the casing portion 5, and further, the cylindrical inner cylindrical portion 7 is incorporated in the outer cylinder portion 6 so as to have the same center axis direction as the outer cylinder portion 6 and eccentrically (see FIGS. 4 and 5). A temperature measuring device 23 is attached to the casing 5 of the combustion chamber 1 so that the temperature inside the wall of the combustion chamber 1 can be measured. The tip of the temperature measuring device 23 is not in contact with the front plate portion 8. A preferable thermometer 23 is a thermocouple.

  In the combustion chamber 1 of the PM generator 10, the cylindrical outer cylinder portion 6 communicates with an air inlet 113 to which light oil combustion air is supplied, and the cylindrical inner cylinder portion 7 directly communicates with the air inlet 113. It does not communicate, but communicates with a flame inlet 51 that leads to the pilot burner 2 (pilot burner for fuel) (see FIG. 4). The length in the central axis direction of the outer cylinder portion 6, the front plate portion 8, and the rear plate portion 9 is the length D in the central axis direction inside the cylindrical portion 5a of the housing portion 5 (see FIG. 4). On the other hand, it is 98%. In other words, the ratio of the length in the central axis direction of the outer cylinder portion 6, the front plate portion 8, and the rear plate portion 9 to the axial length D of the cylindrical portion 5a of the housing portion 5 is 98: 100.

  The casing 5 is formed with a flame inlet 51 that leads to the pilot burner 2 and a gas outlet 52 that sends out gas that has generated PM, and the front plate 8 includes an opening 81 that leads to the gas outlet 52. It is incorporated in the cylindrical part 5a of the part 5 to constitute an end face on the gas outlet 52 side, and the rear plate part 9 is provided with an opening 89 leading to the flame inlet 51, and the inside of the cylindrical part 5a of the housing part 5 And constitutes an end face on the flame inlet 51 side. The diameter C of the gas outlet 52 is 25% of the inner diameter A of the outer cylinder portion 6 (see FIG. 4). In other words, the ratio C: A between the diameter C of the gas outlet 52 and the inner diameter A of the outer cylinder portion 6 is 25: 100. In the combustion chamber 1, the front plate portion 8 and the outer cylinder portion 6 are not integrated, but the rear plate portion 9 and the inner cylinder portion 7 are integrated. Further, a gasket 301 is inserted between the ring 4 and the casing 5, and a non-expanded ceramic fibrous mat (not shown) is inserted between the rear plate 9 and the casing 5.

  In the combustion chamber 1, the outer cylinder portion 6 includes a through hole 61 on its peripheral surface. The through hole 61 is provided so as to form three layers in the central axis direction (lateral direction in FIG. 6) of the cylindrical outer cylinder portion 6, and the central axis direction of the cylindrical outer cylinder portion 6 is provided for each layer. Four are arranged at equal intervals (so that the central angle is 90 °) on the circumference of the cross section perpendicular to the vertical axis. That is, the outer cylinder portion 6 is provided with a total of (3 × 4 =) 12 through holes 61. The through holes 61 of the outer cylinder part 6 are all formed to be inclined in the tangential direction (direction of the peripheral surface of the outer cylinder part) of the cross section (circular or annular shape) perpendicular to the central axis direction of the outer cylinder part 6. As a result of the through hole 61 being inclined (see FIG. 5), an elliptical opening is formed on the surface of the outer cylinder portion 6 (see FIG. 6). The diameter B of the through hole 61 is 7% of the inner diameter A of the outer cylinder portion 6 (see FIG. 5). In other words, the ratio B: A between the diameter B of the through-hole 61 and the inner diameter A of the outer cylinder portion 6 is 7: 100. As shown in FIG. 5, the diameter B of the through hole 61 is not determined by the elliptical opening on the surface of the outer cylinder portion 6, but the diameter of the cross section perpendicular to the central axis direction of the through hole 61 itself. As required.

  On the other hand, the inner cylinder part 7 is provided with a through hole 71 on its peripheral surface. The through-hole 71 is provided so as to form two layers in the central axis direction (lateral direction in FIG. 6) of the cylindrical inner cylinder portion 7, and the central axis direction of the cylindrical inner cylinder portion 7 is provided for each layer. Four are arranged at equal intervals (so that the central angle is 90 °) on the circumference of the cross section perpendicular to the vertical axis. That is, the inner cylinder portion 7 is provided with a total of (2 × 4 =) 8 through holes 71. The through-holes 71 of the inner cylinder part 7 are not formed to be inclined at all, and the normal direction (from the circumferential surface to the central axis) of the cross section (circular or annular shape) perpendicular to the central axis direction of the inner cylinder part 7 (See FIG. 5), and as a result, a circular opening is formed on the surface of the inner cylinder portion 7 (see FIG. 6).

  In the PM generator 10, the outer cylinder portion 6 communicates with an air inlet 113 to which light oil combustion air is supplied, and the cylindrical inner cylinder portion 7 does not communicate directly with the air inlet 113. The pilot burner 2 (the flame inlet 51 leading to) communicates with (see FIG. 4). The light oil 131 injected into the space 101 between the casing 5 and the outer cylinder 6 by the light oil injection means 3 is vaporized, and the outer cylinder 6 and the inner cylinder via the through hole 61 of the outer cylinder 6. 7 is introduced into the space 102 between the two and burned. At this time, since the light oil injection means 3 is provided in the housing part 5 so that the injection direction of the light oil 131 is inclined as described above, the light oil injection means 3 is provided between the housing part 5 and the outer cylinder part 6. The light oil injected into the space 101 is introduced into the space 102 between the outer cylinder part 6 and the inner cylinder part 7 through the through hole 61 of the outer cylinder part 6 while going around the peripheral surface of the outer cylinder part 6. (See FIG. 7).

  The light oil combustion air 132 continuously supplied from the air inlet 113 to the space 101 between the casing 5 and the outer cylinder 6 travels around the peripheral surface of the outer cylinder 6 and passes through the through hole 61 of the outer cylinder 6. Is introduced into the space 102 between the outer cylinder part 6 and the inner cylinder part 7 (see FIG. 7). The light oil 131 intermittently injected into the space 101 between the casing 5 and the outer cylinder 6 passes through the through hole 61 of the outer cylinder 6 while rotating around the outer surface of the outer cylinder 6. The gas oil introduced into the space 102 between the outer cylinder portion 6 and the inner cylinder portion 7 is in contact with the light oil combustion air 132 (outer side), and the non-contact side (inner side) light oil is cut off from the air, It becomes steamed by the heat of combustion, PM is generated, becomes PM-containing gas 133, and is supplied from the gas outlet 52 to an exhaust gas purification device or the like. In the PM generator 10, the outer cylinder portion 6, the inner cylinder portion 7, the front plate portion 8, and the rear plate portion 9 are all formed of Inconel material, and the incomplete combustion that generates the PM is all It occurs in a space surrounded by a member made of Inconel material. The air inlet 113 is provided in the vicinity of the light oil injection means 3 and has a structure that is convenient from the viewpoint of compactness of the apparatus and improvement of maintenance.

  PM generator 10 shall be formed with ceramic material (silicon nitride) instead of forming all of outer cylinder part 6, inner cylinder part 7, front board part 8, and rear board part 9 with inconel material. You can also. When the ceramic material (silicon nitride) is used in this way, the durability performance of the PM generator 10 is improved. Furthermore, since the ceramic material is less susceptible to thermal deformation than the metal material, there is an advantage that it is possible to prevent a decrease in the amount of PM generated due to the thermal deformation.

  Here, using the coordinate axes shown in FIG. 7, the position of the light oil injection means 3 and the through hole 61 in the PM generator 10, and the direction in which the central axis of the inner cylindrical portion 7 deviates from the central axis of the outer cylindrical portion 6. Will be described. The coordinate axes in FIG. 7 are made up of an X axis and a Y axis set so as to pass through the central axis and make a right angle to each other in a cross section perpendicular to the central axis direction of the cylindrical portion of the casing 5.

  In the PM generator 10, when the inner wall of the cylindrical portion of the casing 5 is located at Y = + 100 on the coordinate axis, the light oil injection means 3 is in the position of Y = + 60 and the light oil is injected. The casing 5 is provided so that the direction is parallel to the X axis. The position where the through hole 61a which is one of the through holes 61 of the outer cylinder part 6 is provided is a position of Y = + 70. As described above, the outer cylinder part 6 and the inner cylinder part 7 are eccentric, but this is realized by the center axis of the inner cylinder part 7 being shifted from the center axis of the outer cylinder part 6 to the -Y side. Yes. That is, the light oil injection means 3 is provided on the + Y side on the coordinate axis, and the outer cylinder portion 6 and the inner cylinder portion 7 are decentered on the opposite -Y side. In the PM generator 10, the angle θ formed by the through hole 61 a that is one of the through holes 61 of the outer cylinder portion 6, the origin O of the coordinate axis, and the light oil injection means 3 is 27 °. .

  Next, the filter (PF) evaluation method according to the present invention will be described by taking the case of using the filter evaluation system 100 as an example. When evaluating the PF, PFm (filter, which is a measurement filter) is stored in the storage chamber 90. Then, in the PM generator 10, the light oil 131 is injected intermittently into the light oil combustion air 132 by specifying the excess air ratio λ, and preferably burned at a temperature of 750 ° C. or higher and 1050 ° C. or lower. In the gas, PM having a specific particle size distribution is generated, and the gas in which the PM is generated is supplied to PFm.

  Light oil injection pressure, light valve opening time (light oil injection time), valve opening period (light oil injection period), duty ratio (Duty ratio), and light oil combustion air flow rate by the light oil injection means 3 provided in the PM generator 10 , The excess air ratio λ can be specified or changed. The duty ratio is a ratio between the valve opening time and the valve opening cycle, and is expressed by valve opening time / valve opening cycle. When the valve is opened, the light oil is injected, and when the valve is closed, the injection of the light oil is stopped (not injected). For example, the excess air ratio λ can be adjusted by fixing the valve opening cycle and changing the valve opening time. However, the adjustment amount of the excess air ratio λ according to the valve opening time is small, and it is easier to adjust the opening period when specifying or changing the excess air ratio λ.

  When the excess air ratio λ is changed, the particle size distribution of the PM generated in the gas changes. Therefore, if the excess air ratio λ is adjusted, the exhaust gas discharged from the automobile after driving in the NEDC mode is changed. It is possible to immediately generate a PM-containing gas having a particle size distribution equivalent to the particle size distribution.

  The excess air ratio λ (lambda) is a ratio indicating how far the actual air-fuel ratio is away from the theoretical value, and the excess air ratio λ is (the amount of air supplied (for light oil combustion)) / ( The amount of air theoretically required (for light oil combustion). If λ <1, the air is insufficient (although it is referred to as excess air ratio λ in the present specification as described above), and the mixture is rich. On the other hand, if λ> 1, the air is excessive and the mixture is lean. The excess air ratio λ can also be calculated based on the amount of light oil supplied to the light oil combustion chamber and the flow rate of the light oil combustion air for a certain time (for example, 1 minute).

  If the particle size distribution of the PM in each gas (PN for each particle size) in the gas before passing through PFm and the gas passing through PFm is measured by the particle size distribution measuring devices 93 and 94, PFm PN removal ability can be confirmed (for each particle size).

  That is, measuring the particle size distribution of PM in the gas includes measuring the PN for each particle size (range). When the filter evaluation system has a diluter (91, 92) as in the filter evaluation system 100, the gas can be diluted before measurement by the particle size distribution measuring device (93, 94). By diluting, for example, when the amount of PM generated by the PM generator is large, it is possible to avoid the measurement range over in the particle size distribution measuring apparatus. In addition, when the filter evaluation system has a soluble organic component removing device, the soluble organic component in the gas can be removed before measurement by the particle size distribution measuring device.

  Also, the PN of the particle size excluding the extremely small particle size (20 nm or less) is obtained in the gas before passing through PFm and the gas passing through PFm, and is divided by the PN in the gas before passing through PN in the passed gas. Then, the PN ratio (number ratio of particulate matter, which will be described later) in the PFm is obtained. This is process A. The PN of the particle size excluding the minimum particle size (20 nm or less) can be summed by excluding the minimum particle size (20 nm or less) range from the PN of each particle size range measured by the particle size distribution measuring device. Calculated as PN per unit time.

  Based on the obtained PN ratio, the number of particulate matter per unit travel distance (PN emission, which will be described later) of exhaust gas exhausted from an actual vehicle equipped with PFm is estimated. This is process B. As described above, PFm (filter, measurement filter) can be evaluated.

  In order to evaluate PF more accurately and accurately, correction is performed as follows. PFs (filter, which is a standard filter) is stored in the storage chamber 90 under the same conditions as in the above process A, and the gas generated by the PM generator 10 is supplied to the PFs and before passing through the PFs. PN is obtained from the gas and the gas that has passed through the PFs, and is divided by the PN in the gas that has not passed through the PN in the gas that has passed through to obtain the PN ratio (number ratio of particulate matter) in the PFs. This is process C.

  At the same time, the same PFs are mounted on an actual vehicle, and the PN emission of the exhaust gas discharged from the vehicle (passed through the PFs) is measured. This is process D. That is, in the process C, data is obtained using a filter evaluation system (PM generator), whereas in the process D, data is obtained using an actual vehicle in conformity with PMP.

  Then, the above processes C and D are performed for a plurality of PFs, an approximate expression is obtained from the relationship between the PN ratio obtained in process C and the PN emission obtained in process D, and the above process is performed based on the approximate expression. The PN emission of PFm estimated by B may be compensated.

  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 Examples 1 to 3) Using the filter evaluation system 100, a PM-containing gas is produced and supplied to the storage chamber 90 containing the DPF, and the inlet side of the storage chamber 90 (before being processed with the DPF) The PM-containing gas is diluted with the diluter 91 and introduced into the particle size distribution measuring device 93, and after 60 seconds (Reference Example 1), 250 seconds (Reference Example 2), and 500 seconds (Reference) from the start of measurement. The results of the particle size distribution of each PM in Example 3) are shown in FIG. In addition, model number MD19-2E manufactured by Matter was used as the diluter 91, and the dilution factor was 200 times. As the particle size distribution measuring device 93, model number 3091 (FMPS) manufactured by TSI was used. The light oil injection pressure by the light oil injection means 3 provided in the PM generator 10 is 0.25 MPa, and the valve opening time (light oil injection time) is 2.8 msec. (Milliseconds), valve opening cycle (light oil injection cycle) is 58 msec. (Milliseconds), the duty ratio is 4.8%, and the flow rate of the light oil combustion air sent to the light oil combustion chamber 1 is 0.30 Nm ³ / min. (Min), and secondary air is applied to the downstream side of the light oil combustion chamber 1 (of the PM generator 10 not shown in FIG. 1) so that the excess air ratio λ becomes 1.2, and the total air The flow rate was 1.9 Nm ³ / min. (Minutes). The temperature on the inlet side of the storage chamber 90 was 186 ° C.

  Reference Example 4 A 2.0 L (Euro 4 compliant) diesel engine vehicle equipped with a DPF was operated in NEDC mode compliant with PMP, and exhaust gas was collected on the DPF inlet side. And the particle size distribution of PM was measured using the same particle size distribution measuring apparatus as the reference example 1 by making the object into the exhaust gas. The results are shown in FIG. 9 so that they can be compared with Reference Example 1. However, in FIG. 9, the PM concentration on the vertical axis does not take into account the amount of dilution that occurs on the measurement system.

(Discussion 1) The particle size distribution is a PM concentration for each particle size, and this PM concentration [pieces / cm ³ ] is a PN per unit volume. From the result shown in FIG. 9, if the PM generator 10 is operated under a specific condition (excess air ratio λ) using the filter evaluation system 100 according to the present invention, the PM-containing gas supplied from the PM generator 10 The particle size distribution of PM (PN for each particle size) is roughly equivalent to the PM particle size distribution (PN for each particle size) in exhaust gas obtained by operating a diesel engine vehicle in NEDC mode compliant with PMP It can be seen that The particle size distribution of PM obtained using the filter evaluation system 100 according to the present invention after 60 seconds, 250 seconds, and 500 seconds is determined by operating a diesel engine vehicle in NEDC mode compliant with PMP. It almost coincides with the particle size distribution of PM in the obtained exhaust gas. In the present specification (including figures and tables), a conventional display for a computer may be used as an index display. For example, 1.0 × 10 ⁵ is represented as 1.0E + 5, and both are 100,000.

  [PM Concentration Behavior] FIG. 10 shows an example of changes in PM concentration at the entrance and exit sides of the DPF over time. This is an example of data using the filter evaluation system 100 that records changes in PM concentration over time on the DPF inlet side and outlet side from the initial stage of use in a new (or after regeneration) DPF. . As shown in FIG. 10, the PM concentration on the inlet side of the DPF is substantially constant, but the PM concentration on the outlet side of the DPF is initially high and gradually decreases. As shown in FIG. 10, in the (new) DPF, pores having a size exceeding the size of PM are formed, and at the initial stage, PM leaks from the pores and gradually becomes finer due to PM. The pores are filled and PM is supplemented by pores having a size smaller than that of PM.

[PN Ratio] A value obtained by dividing the PM concentration per predetermined time on the outlet side of a PF (filter, eg, DPF or GPF) by the PM concentration per same time on the inlet side of the PF is referred to as a PN ratio. This is the ratio of the outlet side to the inlet side of the PF with respect to the number per unit volume (PM concentration). The PN can be calculated by multiplying the PM concentration per unit time by a predetermined time and the suction flow rate of the particle size distribution measuring device. Here, since the suction flow rates of the particle size distribution measuring apparatuses on the inlet side and the outlet side are set to be the same, the term of the suction flow rate can be substantially deleted when obtaining the PN. Therefore, in this specification, it will be called a PN ratio, not a PM concentration ratio. The PM concentration per predetermined time is obtained by PM concentration [piece / cm ³ ] × time [second (sec.)]. Based on FIG. 10, for example, the PM concentration on the outlet side of the DPF is divided by the PM concentration on the inlet side of the DPF in the interval of 40 to 120 [sec.] After 40 seconds from the actual start of measurement. Then, the PN ratio in the section of 40 to 120 [seconds (sec.)] Is obtained. Note that the rise of the PM concentration in FIG. 10 is from 40 seconds after the start of measurement. In addition, in the PN emission conforming to PMP, the number of PM particles of 20 nm or less is not counted, so the PM concentration here is also calculated without counting the particle size of 20 nm or less on both the inlet side and the outlet side. . When a diluter is used, the magnification is corrected at this calculation stage.

  [PN Emission] The PN per unit mileage of exhaust gas discharged from an actual diesel engine vehicle equipped with a DPF, measured by a PN measurement method compliant with PMP, is referred to as PN emission [# / km]. # Is the number of PMs. PMP is a means for evaluating DPF, but in this specification, GPF is also handled in the same manner. That is, the PN per unit mileage of exhaust gas discharged from an actual gasoline engine vehicle equipped with GPF, measured by a PN measurement method compliant with PMP, is also referred to as PN emission [# / km]. The PN measuring method based on PMP in this specification is a measuring method using a particle number measuring device sold by Tokyo Direc Co., Ltd. This particle number measuring apparatus includes a sample gas suction classifier PCF2.5 (CY2.5-1) manufactured by Matter, a diluter MD19-3E manufactured by Matter, a volatile component removing apparatus ASET15-1 manufactured by Matter, and TSI. It consists of an agglomerated particle counter CPC3790 made by the company and an interface CU-1ET made by Matter.

  (Example 1) [Measurement of PN emission (actual measurement)] A 2.0 L (Euro 4 compliant) diesel engine vehicle equipped with DPF (Sample A) is operated in NEDC mode compliant with PMP, and processed with DPF. The PN emission [# / km] of the exhaust gas was measured. Further, the DPF was changed to samples B, C, and D, and PN emission [# / km] was measured in the same manner. The results are shown in Table 1 together with the specifications of the DPF used.

  [Calculation of PN ratio (first time)] The filter evaluation system 100 was used to store DPF (sample A) in the storage chamber 90. Then, a PM-containing gas is produced by the filter evaluation system 100, supplied to the storage chamber 90, and the PM-containing gas on the inlet side of the storage chamber 90 (before being processed by the DPF) is diluted by the diluter 91 to obtain a particle size. Introduced into the distribution measuring device 93, the particle size distribution of PM was measured, and the PM concentration was obtained every time. At the same time, the PM-containing gas on the outlet side of the storage chamber 90 (after being treated with the DPF) is diluted by the diluter 92 and introduced into the particle size distribution measuring device 94 to measure the particle size distribution of PM, and PM The concentration was determined every time. Then, the first PN ratio [%] in the section of 0 to 180 seconds (sec.) Was obtained with 0 as the time when the measurement was actually started. In addition, the DPF was changed to Samples B, C, and D, and the first PN ratio [%] was obtained in the same manner. The conditions of the individual devices constituting the filter evaluation system 100 and the PM generator 10 for generating PM are the same as those in the first reference example.

[Calculation of correlation coefficient (first time)] The measured PN emission [# / km] and the first PN ratio [%] of samples A, B, and D were correlated and plotted in FIG. 11A. Then, a correlation coefficient R ² between these PN emissions and the first PN ratio was obtained. The results are shown in Table 2.

[Estimation of PN emission in sample C (first time)] Based on plots of samples A, B, and D other than sample C (estimated from samples A, B, and D), a power approximation formula (Y = aX ^b ) PN emission [# / km] of sample C was estimated based on the power approximation formula and the first PN ratio [%] of sample C. The results are shown in Table 2 and FIG. 11A. As for the power approximation formula, Table 2 shows only a and b.

[2nd to 5th times] Similar to the 1st time, the PN ratios for the 2nd time to the 5th time are calculated, and the correlation coefficients R2 for the ^2nd time to the 5th time are calculated for each day. It was. Similarly to the first time, the measured PN emission [# / km] and the obtained first PN ratio [%] were plotted in FIG. 11A in each of the second to fifth times. . Then, based on the plots of samples A, B, and D other than sample C (estimated from samples A, B, and D), a power approximation formula (Y = aX ^b ) is obtained in each of the second to fifth times, Based on the power approximation formula and the PN ratio [%] of the sample C, the PN emission [# / km] in the second to fifth samples C was estimated. The results are shown in Table 2. When each embodiment is performed on another day, the filter evaluation system (PM generator) is started up each time.

  [Average value and (maximum value-minimum value)] The average value and (maximum value-minimum value) of the first to fifth PN emissions in the estimated sample C were determined. Note that (maximum value−minimum value) is a difference between the maximum value and the minimum value. The results are shown in Table 2.

(Comparative Example 1) Based on the first power approximation formula (Y = aX ^b ) of Example 1 and the PN ratio [%] of each of the second to fifth samples C, the second to The PN emission [# / km] of each sample C for the fifth time was estimated. Further, the same value as in Example 1 was used as the PN emission [# / km] of the first sample C, and the average value of the first to fifth PN emissions in the sample C and (maximum value−minimum value) Asked. The results are shown in Table 2.

(Example 2, Comparative Example 2) The interval for obtaining the PN ratio [%] was changed to 0 to 240 seconds (sec.). Otherwise, the test was performed in the same manner as in Example 1 and Comparative Example 1. That is, the first to fifth PN ratio calculation, the measured PN emission [# / km] and the obtained first to fifth PN ratio [%] are related to the plot, the first to the fifth Calculation of correlation coefficient R ² Estimation of PN emission [# / km] in first to fifth samples C (Example 2) Estimation of PN emission [# / km] in second to fifth samples C (Comparative Example 2), calculation of average value and (maximum value-minimum value) were performed. The results are shown in Table 3 and FIG. 11B.

(Example 3, Comparative Example 3) The interval for obtaining the PN ratio [%] was changed to 0 to 300 seconds (sec.). Otherwise, the test was performed in the same manner as in Example 1 and Comparative Example 1. That is, the first to fifth PN ratio calculation, the measured PN emission [# / km] and the obtained first to fifth PN ratio [%] are related to the plot, the first to the fifth Calculation of correlation coefficient R ² Estimation of PN emission [# / km] in first to fifth samples C (Example 3) Estimation of PN emission [# / km] in second to fifth samples C (Comparative Example 3), calculation of average value and (maximum value-minimum value) were performed. The results are shown in Table 4 and FIG. 11C.

(Discussion 2) In Examples 1 to 3, when estimating the PN emission [# / km] of the sample C from the PN ratio [%] of the sample C, each time (in each of the first to fifth times), the sample C A power approximation formula (Y = aX ^b ) is obtained based on plots of samples A, B, and D other than the above. Then, the PN emission [# / km] of the sample C is corrected by the power approximation formula. Since the value of the PN ratio of the sample C is an intermediate value of the PN ratios of the samples B and D, this correction corresponds to interpolation (interpolation). On the other hand, in Comparative Examples 1 to 3, when estimating the PN emission [# / km] of the sample C from the PN ratio [%] of the sample C, the first power approximation formula is used even if it is the second to fifth times. We are using. There is a clear correlation between the PN ratio and the PN emission, and in Comparative Examples 1 to 3, an actual vehicle equipped with a DPF is operated in the NEDC mode compliant with PMP and the PN emission is measured. However, it is possible to estimate the PN emission from the PN ratio. However, it can be seen that PN emissions can be estimated more accurately and accurately than those of Comparative Examples 1 to 3 as in Examples 1 to 3 (see Table 1).

  (Example 4) [Calculation of PN ratio (first time)] The filter evaluation system 100 was used to store DPF (sample A) in the storage chamber 90. Then, the PM-containing gas is produced by the filter evaluation system 100 and supplied to the storage chamber 90. The PM-containing gas on the inlet side of the storage chamber 90 (before being processed by the DPF) is diluted by the diluter 91, Introduced into the distribution measuring device 93, the particle size distribution of PM was measured, and the PM concentration was obtained every time. At the same time, the PM-containing gas on the outlet side of the storage chamber 90 (after being treated with the DPF) is diluted by the diluter 92 and introduced into the particle size distribution measuring device 94 to measure the particle size distribution of PM, and PM The concentration was determined every time. And a section of 0 to 30 seconds (sec.), A section of 0 to 60 seconds (sec.), A section of 0 to 120 seconds (sec.), A section of 0 to 180 seconds (sec.), And 0 to 240 seconds. (Sec.), 0-300 seconds (sec.), 0-360 seconds (sec.), 0-420 seconds (sec.), 0-480 seconds (sec.) The first PN ratio [%] was determined. Also, without stopping the PM generator 10, the DPF was changed to the samples B and D, and similarly, the first PN ratio [%] was obtained for each section. The conditions of the individual devices constituting the filter evaluation system 100 and the PM generator 10 for generating PM are the same as those in the first reference example.

[Calculation of correlation coefficient (first time)] The measured PN emission [# / km] is correlated with the first PN ratio [%] for each section in samples A, B, and D, and plotted in the figure and, a correlation coefficient R ² between the PN emissions and first PN ratio, for each section was determined. The results are shown in Table 5.

[2nd to 5th] In the same way as the 1st, change the day, calculate the PN ratio for each section for the 2nd to 5th, and calculate the correlation coefficient R2 for the ^{2nd to} 5th. Calculation was performed for each section. The results are shown in Table 5.

[Average value, maximum value, minimum value] Mean value of the correlation coefficient R ² of each interval, maximum value, minimum value, shown in FIG. 12.

  (Discussion 3) From the results shown in FIG. 12, measurement (actual measurement) was performed in a section of 0 to 120 seconds (sec.), A section of 0 to 180 seconds (sec.), And a section of 0 to 240 seconds (sec.). It can be seen that the correlation between the generated PN emission [# / km] and the PN ratio [%] is high.

  The filter evaluation method according to the present invention can be used as a DPF PN removal capability evaluation means under the same conditions as in the case of using the NEDC mode and the PMP PN measurement method. In other words, the filter evaluation method according to the present invention is suitably used as a DPF development tool for automobiles for Europe. The filter evaluation method according to the present invention can also be suitably used as a PN removal capability evaluation means of GPF.

1: combustion chamber, 2: pilot burner, 3: light oil injection means, 4: ring, 5: casing, 5a: cylindrical part (of casing), 6: outer cylinder, 7: inner cylinder, 8: Front plate portion, 9: Rear plate portion, 10: PM generator, 11: Flame detector, 23: Temperature measuring device, 51: Flame inlet, 52: Gas outlet (generating PM), 53: Division Surface, 61, 61a: through hole, 71: through hole, 81: opening, 89: opening, 90: storage chamber, 91, 92: diluter, 93, 94: particle size distribution measuring device, 95, 96: sample system 97: piping, 100: filter evaluation system, 101: space, 102: space, 113: air inlet, 131: light oil, 132: air for light oil combustion, 133: gas containing PM, 144: blow valve, 301: gasket.

Claims (5)

Supply the gas in which the particulate matter is generated using the PM generator to the measurement filter, determine the number of each particulate matter in the gas before passing through the measurement filter and the passed gas, Dividing the number of particulate matter by the number of particulate matter in the gas before passing through to obtain the number ratio of particulate matter in the measurement filter;
A process B for estimating the number of particulate matter per unit mileage of exhaust gas exhausted from an actual vehicle equipped with the measurement filter, based on the obtained number ratio of particulate matter,
Supply the gas in which the particulate matter is generated using the PM generator to the standard filter, obtain the number of the particulate matter in the gas before passing through the standard filter and the passed gas, Dividing the number of particulate matter by the number of particulate matter in the gas before passing through to determine the number ratio of particulate matter in the standard filter;
A process D of measuring the number of particulate matter per unit mileage of exhaust gas exhausted from an actual automobile equipped with the standard filter, and
Steps C and D are performed on a plurality of standard filters, and an approximation obtained from the relationship between the number ratio of particulate matter obtained in Step C and the number of particulate matter per unit mileage obtained in Step D. A filter evaluation method that compensates for the number of particulate matter per unit mileage applied to the measurement filter estimated in the process B based on an equation . The filter evaluation method according to claim 1 , wherein the number of the plurality of standard filters performing the process C and the process D is three or more. The number ratio of the particulate matter in the measurement filter in the process A is
The number ratio of the particulate matter in the standard filter in the process C is smaller than the maximum value and larger than the minimum value.
Evaluation method of filter according to claim 1 or 2 wherein the plurality of standard filter is selected. The PM generator can mix fuel and fuel combustion air, and can inject the fuel intermittently into the fuel combustion chamber that generates combustion of the mixed fuel mixture. And a fuel pilot burner for igniting the fuel mixture,
The method for evaluating a filter according to any one of claims 1 to 3 , wherein the particulate matter is generated in the gas due to incomplete combustion of the fuel mixture. In the PM generator, the fuel is injected into the fuel combustion air with an excess air ratio λ, intermittently injected, burned, and the gas has a particulate size distribution having a specific particle size distribution. The method for evaluating a filter according to any one of claims 1 to 4 , wherein a substance is generated.

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