JP4667344B2 - PM generator - Google Patents

Description

  The present invention relates to a PM generator that generates particulate matter (PM) in a gas and a PM generation method in order to evaluate an exhaust gas purification device that includes 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. Particularly the particulate matter (Particulate Matter, PM) discharged from a diesel engine or a NO _X (nitrogen oxides) and the like are enormous influence, regulations on which are strengthened worldwide. Therefore, research and development of exhaust gas purifiers equipped with a filter (Diesel Particulate Filter, DPF) for removing PM and a catalyst useful for reducing NO _X to nitrogen and water, etc. have been advanced. Purification devices are now available on the market.

  However, the present situation is that no means has been proposed for testing the exhaust gas purification device and evaluating its performance and durability with high accuracy. There are not many related literatures, and an evaluation gas supply device (Patent Literature 1), a vaporized gas supply device (Patent Literature 2), and a gas analysis test device (Patent Literature 3) are known. (See Patent Document 1), or specific means for exhaust gas generation have not been clarified (see Patent Documents 2 and 3). .

  Hereinafter, the prior art will be described. As a means for evaluating the performance and the like of the exhaust gas purification device, first, there is a method of supplying exhaust gas from an actual automobile engine or the like to the exhaust gas purification device and analyzing the processing gas. Also, using PM collected from carbon powder and actual exhaust gas, this is mixed into the gas to produce exhaust gas that simulates the exhaust gas from an actual automobile engine and supplied to the exhaust gas purification device A method for analyzing the processing gas is known (see Patent Document 1). Furthermore, a method of generating exhaust gas containing PM by burning light oil or hydrocarbon and a method of generating exhaust gas containing PM by sparking a graphite electrode are known, and the exhaust gas obtained by using these is used. Thus, it is possible to evaluate the performance and the like of the exhaust gas purification device (see Patent Document 1).

JP-A-2005-214742 Japanese Patent Laid-Open No. 10-318888 JP-A-10-319006

  However, the method of using exhaust gas from an actual automobile engine has a problem that the equipment becomes large and expensive. In addition, in the method of manufacturing exhaust gas that simulates exhaust gas from an automobile engine (see Patent Document 1), it is different from the fuel that is actually used, or because PM that has been once collected is used, As mentioned above, there was a problem that it could not be said that the actual exhaust gas was sufficiently simulated. Further, the method of generating exhaust gas containing PM by burning light oil or hydrocarbon is difficult to control the amount of PM generated and easily misfires, and a method of generating exhaust gas containing PM by sparking a graphite electrode Then, there was a problem that the amount of PM generated was small and a large amount of PM could not be generated in a short time (see Patent Document 1). That is, in any case, there is a problem in the means for generating the exhaust gas for evaluation supplied to the exhaust gas purification device.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is a suitable means for stably producing and supplying an evaluation exhaust gas to be supplied to an exhaust gas purification device. And providing means for accurately evaluating the performance and durability of the exhaust gas purification device with high accuracy. Another object is to provide a means for evaluating the exhaust gas purification device in a short time by generating a large amount of PM in a short time. As a result of repeated studies, it has been found that the above object can be achieved by the following means.

  That is, first, according to the present invention, an apparatus for burning liquid and / or gaseous fuel in a combustion chamber to generate PM in the gas, the combustion chamber and combustion air being supplied to the combustion chamber. Provided is a PM generator (Particulate Matter Generator) having combustion air supply means for supplying and intermittent fuel injection means capable of intermittently injecting fuel into the combustion air supplied to the combustion chamber The The PM generator according to the present invention is a device that generates PM in a gas. In other words, the PM generator according to the present invention manufactures and supplies a gas that generates PM (PM-containing gas). It can be called a device.

  In the PM generator according to the present invention, it is preferable that the intermittent fuel injection means includes an electric valve, and the fuel is intermittently injected by controlling the valve opening time and / or the valve opening interval.

  The PM generator according to the present invention preferably includes a fuel injection pressure adjusting means capable of changing the fuel injection pressure. In this case, the fuel injection pressure adjusting means is preferably a means capable of changing the injection pressure once or twice or more during the fuel injection.

  In the PM generator according to the present invention, the fuel injection pressure is preferably 0.1 MPa or more and 1.0 MPa or less.

  Furthermore, the PM generator according to the present invention comprises a fuel mixing means for obtaining a mixed fuel by previously mixing the liquid fuel and the gaseous fuel before injection when the liquid fuel and the gaseous fuel are used in combination. Is also preferable.

  Still further, the PM generator according to the present invention preferably includes a gas mixing means capable of previously mixing a gas other than the fuel with the fuel before the fuel is injected. In this case, the gas other than the fuel is preferably air.

  In the PM generator according to the present invention, it is preferable that the injection angle of the fuel injected from the intermittent fuel injection means is 5 ° or more and 120 ° or less.

  In the PM generator according to the present invention, the liquid fuel among the fuels is preferably light oil or heavy oil.

  In the PM generator according to the present invention, the valve opening cycle of the intermittent fuel injection means is 10 to 300 msec. It is preferable that

  In the PM generator according to the present invention, the ratio of the valve opening time and the valve opening cycle of the intermittent fuel injection means (duty ratio = valve opening time / valve opening cycle) is 0.05 to 0.6. preferable.

  In the PM generator according to the present invention, the supply destination of the gas (PM-containing gas) that generates PM is an exhaust gas purification device, and is preferably used for evaluating the exhaust gas purification device. In the present specification, the evaluation of the exhaust gas purification device means, for example, the evaluation of the performance and / or durability of the exhaust gas purification device. Further, in the present specification, examples of the exhaust gas purification device to be evaluated include those equipped with a filter for removing particulates in the exhaust gas and / or a catalyst for decomposing harmful substances in the exhaust gas. It is done.

Next, according to the present invention, a plurality of the PM generators described above are provided, and the plurality of PM generators are operated under the same conditions, or at least one PM generator is replaced with another one. Control means that can be operated under conditions different from those of the PM generator, and a PM-containing gas mixing means that obtains a mixed PM-containing gas by mixing the gases generated by the PM generators to obtain a mixed PM-containing gas, By supplying the mixed PM-containing gas to the exhaust gas purification device, an exhaust gas purification device evaluation device for evaluating the exhaust gas purification device is provided.

  Next, according to the present invention, a method of burning liquid and / or gaseous fuel to generate PM in the gas, comprising the step of intermittently mixing and burning the fuel in the combustion air. A PM generation method is provided.

  The PM generator according to the present invention includes intermittent fuel injection means and can intermittently inject fuel into combustion air, so that a large amount of PM is generated in the gas and the PM containing the large amount of PM. The contained gas can be supplied safely and stably. Problems such as misfiring are unlikely to occur even during continuous operation. When fuel is continuously injected into the combustion air, misfire is likely to occur when the amount of PM generated increases, and continuous operation becomes impossible. However, according to the present invention, such a problem can be avoided.

  Since the PM generator according to the present invention does not use exhaust gas from an actual automobile engine or the like, the facility can be further downsized and the cost can be suppressed. Further, since the PM once collected is not used, it is possible to arbitrarily select the fuel, and therefore, it is possible to sufficiently simulate the exhaust gas from the actual automobile engine. Therefore, it is suitable as a means for producing and supplying an exhaust gas for evaluation to be supplied to the exhaust gas purification device.

  According to a preferred embodiment of the PM generator of the present invention, the fuel intermittent injection means includes an electric valve, and the fuel is intermittently injected by controlling the valve opening time and / or the valve opening interval. The time for continuously injecting fuel, the time for stopping (not injecting) the fuel, the interval for injecting or stopping the fuel, the pattern thereof, etc. can be freely set. Therefore, it is easy to change the generation amount and / or properties of PM.

  Since the PM generator according to the present invention is provided with the fuel injection pressure adjusting means according to its preferred mode, the PM generation amount and / or properties can be easily changed by changing the fuel injection pressure. .

  The PM generator according to the present invention includes a fuel mixing means that premixes liquid fuel and gaseous fuel to obtain a mixed fuel according to its preferred mode, so that a wide range of fuels can be selected in accordance with actual usage conditions. It is. In addition, it becomes easier to generate an arbitrary amount and / or property of PM by combining liquid fuel and gaseous fuel.

  Since the PM generator according to the present invention includes gas mixing means that can premix gas other than fuel with fuel according to a preferred aspect thereof, even if the fuel is highly viscous and difficult to inject, such as heavy oil. In addition to facilitating injection, it is possible not only to expand the choice of fuel to be used, but also to select an arbitrary fuel so that PM having a wider range of arbitrary properties can be generated.

  According to the preferred embodiment of the PM generator according to the present invention, since the fuel injection angle is 5 ° or more and 120 ° or less, the diffusion of the fuel is improved, so that the combustion is more stable and the occurrence of misfire can be prevented. .

An exhaust gas purifying apparatus evaluation apparatus according to the present invention includes a plurality of PM generators according to the present invention, and operates the plurality of PM generators under the same conditions or generates at least one PM. A control means capable of operating the apparatus under conditions different from those of other PM generators, and a PM-containing gas mixing means for obtaining a mixed PM-containing gas by mixing PM-containing gases obtained by a plurality of PM generators. Therefore, the PM-containing gas containing a large amount of PM can be produced safely and stably in a short time without misfire and supplied to the exhaust gas purification device. Further, in each PM generator, the properties of the mixed PM-containing gas can be finely adjusted by changing the fuel to be used, the interval at which the fuel is injected or stopped, the fuel injection pressure, and the like. Therefore, it is suitable as means for accurately evaluating the performance and durability of the exhaust gas purifying apparatus with high accuracy.

  Since the PM generation method according to the present invention includes a step of intermittently mixing and burning fuel in combustion air, a large amount of PM is generated in the gas, and the PM-containing gas containing the large amount of PM is misfired. It is possible to manufacture safely and stably without doing. When fuel is continuously mixed in combustion air and burned, it is easy to misfire and continuous operation becomes impossible, and the amount of PM that can be produced is limited. The problem can be avoided.

  Hereinafter, embodiments of the present invention will be described with appropriate reference to the drawings, 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, the PM generator according to the present invention will be described. FIG. 1 is a block diagram showing an embodiment of a PM generator according to the present invention, and FIG. 5 is a perspective view (cross-sectional view) showing the inside of the PM generator shown in FIG. In FIG. 1, the combustion chamber 1 has a side surface drawn, and FIG. 5 shows a state in which the inside is seen through from the side surface side. A PM generator 10 shown in FIGS. 1 and 5 includes a combustion chamber 1, an intermittent fuel injection means 3 attached to the combustion chamber 1, and a combustion air supply means 4 composed of a compressor. Device.

  In the PM generator 10, the combustion air 132 is supplied into the combustion chamber 1 from the combustion air inlet 151 provided on the side surface of the combustion chamber 1 by the combustion air supply means 4 via the flow path 14. Is done. The combustion air 132 supplied into the combustion chamber 1 is heated in the air preheating chamber 5 in the combustion chamber 1. On the other hand, liquid and / or gaseous fuel 131 is intermittently supplied into the combustion air 132 heated in the combustion chamber 1 (air preheating chamber 5) by the fuel intermittent injection means 3 via the flow path 13. Injected at. Here, the baffle plate 6 is provided in the combustion chamber 1, and the fuel 131 is injected in a direction toward the combustion cylinder 7.

  The fuel 131 is diluted with the combustion air 132 in the combustion chamber 1. The fuel 131 diluted with the combustion air 132 is ignited by the pilot burner 2 and then combusted in the combustion cylinder 7 to generate PM. The PM-containing gas (PM-containing gas 133) is sent from the gas outlet 152 of the combustion chamber 1 (to the left in FIG. 1) and supplied to, for example, an exhaust gas purification device for evaluation.

  The combustion chamber 1 is configured as a box whose internal space has a cylindrical space and a mortar-like space that gradually narrows in the gas flow direction (see FIG. 5). The pilot burner 2, the intermittent fuel injection means 3, and the flame detector 11 are disposed on the end surface (the right end surface in FIG. 1) opposite to the end surface on the gas outlet 152 side where the PM-containing gas 133 is delivered. Is attached. The PM generator 10 is an apparatus capable of intermittently injecting fuel. Even when producing a PM-containing gas containing a large amount of PM, misfire is unlikely to occur. However, in order to ensure safety, a flame detector is used. 11 is provided. The fuel flow path 13 and the combustion air 132 flow path 14 are constituted by pipes. The pilot burner 2 is used when first ignited at the start of use. Except for the first ignition at the start of use, fuel and air are not supplied, and the combustion of the fuel injected from the intermittent fuel injection means 3 is continued by the residual heat in the combustion chamber 1. It goes without saying that fuel and air may be supplied to the pilot burner 2 and combustion of the pilot burner 2 may be continued as necessary. The fuel used for the pilot burner 2 may be of any kind, but gaseous fuel such as propane is preferable in handling.

  The intermittent fuel injection means 3 is composed of an injector having an electric valve function. Therefore, by controlling the intermittent fuel injection means 3 itself by the control device of the PM generator 10 not shown in FIG. 1, the injection time (valve opening time), the stop time, their interval (cycle), or injection / stop The pattern etc. can be set freely. Of course, the PM generator according to the present invention comprises an injection nozzle and a motorized valve provided independently in the fuel flow path (corresponding to the flow path 13), and the valve opening time and / or opening of the motorized valve. The intermittent fuel injection means may be realized by controlling the valve interval (valve opening period).

  The intermittent fuel injection means 3 (injector) further has a fuel injection pressure adjustment function. Therefore, by controlling the intermittent fuel injection means 3 itself with the control device, the fuel injection pressure can be freely changed even in the middle of the injection. Of course, the PM generator according to the present invention includes an injection nozzle and an independent (automatic or manual) pressure adjusting mechanism provided in the fuel flow path (corresponding to the flow path 13). The fuel injection pressure may be changed by automatic control, manual adjustment, or switching between a plurality of pressure adjustment mechanisms.

  Although not shown in FIG. 1, the PM generator 10 is provided with a fuel mixing means. When liquid fuel and gaseous fuel are used in combination, the liquid fuel and gaseous fuel are separately supplied to the intermittent fuel injection means 3 (injector). By supplying and mixing inside the intermittent fuel injection means 3 (injector), a mixed fuel previously mixed before injection can be obtained. Similarly, although not shown in FIG. 1, the PM generator 10 is provided with a gas mixing means, and before the fuel is injected, a gas other than the fuel, such as air, can be mixed in advance.

  In the PM generator 10, the injection angle of the fuel injected from the intermittent fuel injection means 3 is approximately 60 °. FIG. 2 is an enlarged cross-sectional view showing a mounting portion of the intermittent fuel injection means 3 in the combustion chamber 1 of the PM generator 10 shown in FIG. In FIG. 2, the injection angle θ of the fuel injected from the tip of the intermittent fuel injection means 3 inserted into the combustion chamber 1 into the combustion chamber 1 (into the combustion air supplied to the combustion chamber 1). Is shown to be approximately 60 °.

  Next, an evaluation apparatus for an exhaust gas purification apparatus according to the present invention will be described. FIG. 3 is a configuration diagram showing an embodiment of an exhaust gas purifying apparatus evaluation apparatus (also simply referred to as an evaluation apparatus) according to the present invention. The evaluation apparatus 20 shown in FIG. 3 includes the four PM generators 10 (Nos. 1, 2, 3, and 4) described above, and the PM-containing gas produced by them is mixed by the PM-containing gas mixing means. Then, by supplying the obtained mixed PM-containing gas to the exhaust gas purification device 32, the exhaust gas purification device 32 can be evaluated. Whether the mixed PM-containing gas is supplied to the exhaust gas purification device 32 by the switching valves 22 and 23 is selected. Further, a temperature detector 33 constituted by, for example, a thermocouple is attached downstream of the switching valves 22 and 23, and detects the temperature of the obtained mixed PM-containing gas. In FIG. 3, detailed portions such as intermittent fuel injection means of each PM generator 10 are omitted and not drawn.

  The PM-containing gas mixing means is No. A secondary air supply unit 31 for adjusting the temperature and / or flow rate of the PM-containing gas produced by the PM generator 10 of Nos. 1, 2, 3 and 4; This is realized by the main header portion 21 that joins and mixes the PM-containing gases produced by the PM generators 1 to 4. That is, in the evaluation device 20, four PM generators 10 are connected in parallel, and finally the mixed PM-containing gas that has joined and mixed with the main header portion 21 is supplied to the exhaust gas purification device 32. In the exhaust gas purifying apparatus evaluation apparatus according to the present invention, the PM-containing gas mixing means is not limited to four, but a plurality of and not the same PM generators having different specifications, and part or all of them are arranged in parallel. This can be realized by the configuration connected to the main header and the main header.

  In the evaluation device 20, the secondary air supply unit 31 is attached to each PM generator 10 on the gas outlet 152 side where the PM-containing gas is delivered. In each secondary air supply unit 31, the secondary air supplied from the flow path 15 by the secondary air supply means such as a compressor (not shown) is mixed and mixed with the PM-containing gas produced by each PM generator 10. By adjusting the flow rate of the secondary air, the PM-containing gas is prepared so as to have a predetermined temperature and flow rate for each PM generator 10. The flow rate of the secondary air is adjusted by the flow meter 28 and the control valve 29. That is, the flow path 15 of the secondary air sent to the secondary air supply unit 31 provided for each PM generator 10 is provided with a flow meter 28 and a control valve 29 for each system, The flow rate of each secondary air can be adjusted. The control valve 29 may be one that can be manually adjusted independently of the flow meter 28, but one that can be automatically controlled based on the detected flow rate of the flow meter 28 is particularly preferable.

  In the evaluation device 20, the four PM generators 10 can be operated under the same conditions, or at least one PM generator 10 can be operated under different conditions from the other three PM generators 10. Control means are provided. This control means is realized by an intermittent fuel injection means (not shown in FIG. 3) having both an electric valve function and a fuel injection pressure adjustment function, and a combustion air flow rate adjustment means respectively provided in the four PM generators 10. The The motor-operated valve can be any of an electromagnetic valve using an electromagnet, a valve that opens and closes by rotation of a motor, a valve that uses piezoelectric ceramics, and the like.

  The combustion air flow rate adjusting means is a means for adjusting the flow rate of the combustion air, and includes a flow meter 24 and a control valve 25. That is, the flow path 14 of combustion air sent to the combustion chamber of each PM generator 10 is provided with a flow meter 24 and a control valve 25 for each system, and the flow rate of each combustion air is controlled. It can be adjusted. The control valve 25 may be one that can be manually adjusted independently of the flow meter 24, but it is preferable that the control valve 25 can be automatically controlled based on the detected flow rate of the flow meter 24.

  By the control device of the evaluation device 20 not shown in FIG. 3, in each of the four PM generators 10, the fuel injection pressure and the injection time and stop time, or their interval, or injection / stop by the fuel intermittent injection means The flow rate of the mixed PM-containing gas finally obtained in the main header portion 21 by adjusting the flow rate of the combustion air, and further adjusting the flow rate of the secondary air described above, It is possible to freely change the temperature, the PM content, the properties of the contained PM, and the like.

In FIG. 3, the side of the exhaust gas purifying device 32 is drawn, and the exhaust gas purifying device 32 that is the object of evaluating performance and / or durability is gradually in the cylindrical space and at both ends. A narrow mortar-shaped box, and a cylindrical space, for example, a filter having a honeycomb structure that removes particulates in exhaust gas, or a catalyst having a honeycomb structure (for example, a honeycomb structure). Catalyst body), which contains a catalyst such as an oxidation catalyst or a three-way catalyst for decomposing harmful substances in the exhaust gas. Although not shown, it is preferable to provide an analysis means for analyzing CO, HC, NO _X , SO _{X and the} like in the gas on the downstream side (exhaust gas outlet side) of the exhaust gas purification device 32.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to a following example.

  (Example 1) Using the PM generator 10 shown in FIG. 1, light oil is used as the fuel, fuel injection pressure by the intermittent fuel injection means using the motor operated valve provided in the PM generator 10, the valve opening time ( Fuel injection time), valve opening cycle (fuel injection cycle), duty ratio, and excess air ratio λ in the PM generator 10 were changed as shown in Table 1 and burned to produce a PM-containing gas. In addition, the time until the occurrence of misfire was measured. And secondary air was mixed with the PM containing gas, and PM containing gas (evaluation gas) used as evaluation object was obtained. Then, the PM-containing gas (evaluation gas) was sucked to measure the amount of PM generated per unit time. The results are shown in Table 1 together with the amount of fuel used.

  [PM Generation Amount] A PM-containing gas (evaluation gas) is sucked and passed through a filter paper (Millipore Corporation glass fiber filter, product number: AP2005500, 55 mm) for a predetermined time (30 seconds to 5 minutes). And the mass of PM adhering to the filter paper was measured with a micro balance (ME-5F manufactured by SARTORUS, 0.001 mg), the flow rate of PM-containing gas (evaluation gas) after mixing secondary air, and then sucked From the gas flow rate and the suction time, the amount of PM generated per unit time (g / Hr) was determined.

  [Excess air ratio λ] The amount of fuel supplied to the combustion chamber and the flow rate of combustion air at a fixed time (for example, 1 second or 1 minute) (if air is mixed with the fuel in advance, the amount of the mixed air) Calculated from the above). In general, when the fuel is rich (λ is small), the amount of PM generated increases. However, when the fuel is thick, misfire tends to occur.

  [Duty ratio] This is the ratio between the valve opening time and the valve opening cycle, and is expressed by valve opening time Ton / valve opening cycle Ttotal as shown in FIG. In FIG. 4, fuel is injected when the valve opening is 100%, and fuel injection is stopped (not injected) when the valve opening is 0%.

  (Examples 2 to 18) A PM-containing gas was produced in the same manner as in Example 1 except that the fuel injection pressure, the valve opening time and the valve opening period (duty ratio), and the excess air ratio λ were changed. And the time until misfire occurrence was measured and PM generation amount per unit time was measured. In particular, in Examples 17 and 18, the fuel injection pressure was changed in two stages. The results are shown in Table 1 together with the amount of fuel used.

  (Comparative Examples 1 to 5) The same apparatus as that used in Example 1 is used except that the fuel injection means that cannot perform intermittent injection is used, and a predetermined excess air ratio λ is set at a predetermined injection pressure. Then, fuel was continuously injected into the combustion air, mixed and burned to produce a PM-containing gas. Other than that was carried out similarly to Example 1, measured the time until misfire generation | occurrence | production, and measured PM generation amount per unit time. The results are shown in Table 1 together with the fuel injection pressure, the excess air ratio λ, and the amount of fuel used. When fuel is continuously injected, the valve opening time and the valve opening cycle are equal, and the duty ratio is 1.

  (Examples 19 and 20) As in Example 1, except that heavy oil is used as the fuel, and the fuel injection pressure, valve opening time and valve opening period (duty ratio), and excess air ratio λ are set to predetermined values. PM-containing gas was produced. And the time until misfire occurrence was measured and PM generation amount per unit time was measured. The results are shown in Table 2 together with the fuel injection pressure, the excess air ratio λ, and the amount of fuel used.

  (Comparative Examples 6-7) The same apparatus as that used in Example 1 is used except that fuel injection means that cannot perform intermittent injection is used, heavy oil is used as fuel, and at a predetermined injection pressure. Then, fuel was continuously injected into the combustion air so as to have a predetermined excess air ratio λ, mixed, and burned to produce a PM-containing gas. Other than that was carried out similarly to Example 1, measured the time until misfire generation | occurrence | production, and measured PM generation amount per unit time. The results are shown in Table 2 together with the fuel injection pressure, the excess air ratio λ, and the amount of fuel used.

  (Example 21) The same apparatus as that used in Example 1 was used except that a fuel injection means for propane was provided. Then, using propane as the fuel, the PM-containing gas was changed in the same manner as in Example 1 except that the fuel injection pressure, the valve opening time and the valve opening period (duty ratio), and the excess air ratio λ were set to predetermined values. Manufactured. Then, the time until misfire was measured, and the amount of PM generated per unit time was measured. The results are shown in Table 3 together with the fuel injection pressure, the excess air ratio λ, and the amount of fuel used.

  (Comparative Example 8) The same apparatus as that used in Example 1 was used except that fuel injection means that cannot perform intermittent injection was used, propane was used as fuel, and predetermined injection pressure was used. The PM-containing gas was produced by continuously injecting and mixing fuel into the combustion air so that the excess air ratio λ was. Other than that was carried out similarly to Example 1, measured the time to misfire, and measured PM generation amount per unit time. The results are shown in Table 3 together with the fuel injection pressure, the excess air ratio λ, and the amount of fuel used.

  (Examples 22 to 25) As fuel, those obtained by previously mixing light oil with air, those obtained by previously mixing light oil and propane, respectively, fuel injection pressure, valve opening time and valve opening cycle (duty ratio), excess air A PM-containing gas was produced in the same manner as in Example 1 except that the rate λ was set to a predetermined value. Then, the time until misfire was measured, and the amount of PM generated per unit time was measured. The results are shown in Table 4 together with the fuel injection pressure, the excess air ratio λ, and the amount of fuel used.

  (Embodiment 26) The evaluation apparatus 20 shown in FIG. 3 was constructed using four PM generators 10 shown in FIG. In the evaluation apparatus 20, four PM generators 10 are operated under the conditions shown in Examples 1 to 25, respectively, and secondary air is added to the PM-containing gas produced by each PM generator 10 in an amount thereof. Were appropriately changed and mixed. As a result, it was confirmed that a mixed PM-containing gas having an arbitrary flow rate, temperature, PM content, and property of (containing) PM was obtained. Then, using a mixed PM-containing gas that is a desired flow rate, temperature, PM content, and PM properties (containing), a DPF having an outer diameter of 100 mm to 380 mm is converted into an exhaust gas purification device, and an outer diameter of 100 mm to 380 mm. Evaluation of an exhaust gas purifying apparatus equipped with the above catalyst was successful.

  (Consideration) From the results of Tables 1 to 4, as shown in Examples 1 to 25, when PM is generated by intermittently injecting and mixing fuel in combustion air to generate PM, it depends on the fuel used. Furthermore, even when the PM generation amount is 10 g / Hr or more, misfire does not occur, and continuous operation for 30 hours or more is possible. In addition, the maximum PM generation amount is as high as 115 g / Hr and can be stably operated. Further, the valve opening cycle of the intermittent fuel injection means is 10 to 300 msec. The operation state was stable under a wide range of conditions with a duty ratio of 0.05 to 0.6.

  On the other hand, as shown in Comparative Examples 1 to 8, when fuel is continuously injected to generate PM, PM is stably burned under a very small amount of PM, but the amount of PM generated is further increased. Attempting to do so makes the combustion unstable. If the PM generation amount is 10 g / Hr or more, misfire is likely to occur, and continuous operation for 1 hour or more cannot be performed. Further, the PM generation amount is limited to 10 g / Hr. By the above Example, the outstanding effect by injecting intermittently has been confirmed.

  Further, from Example 26, it was confirmed that the property of the mixed PM-containing gas can be finely adjusted by the exhaust gas purifying apparatus evaluation apparatus according to the present invention. Since a mixed PM-containing gas having a desired property can be obtained, it is possible to evaluate an exhaust gas purifying apparatus including a DPF or a catalyst having an outer diameter exceeding 380 mm.

  The PM generator and the exhaust gas purification apparatus evaluation apparatus and PM generation method of the present invention are an exhaust gas comprising a filter for removing particulates in exhaust gas and / or a catalyst for decomposing harmful substances in exhaust gas. It is used to evaluate the performance and / or durability of the purification device.

It is a lineblock diagram showing one embodiment of a PM generator concerning the present invention. It is sectional drawing which expands and shows the attachment part of the fuel intermittent injection means of the combustion chamber of PM generator shown by FIG. It is a block diagram which shows one Embodiment of the evaluation apparatus of the exhaust-gas purification apparatus which concerns on this invention. It is explanatory drawing of valve opening time, a valve opening period, and duty ratio. It is a perspective view which shows the inside of PM generator shown by FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Combustion chamber 2 Pilot burner 3 Fuel intermittent injection means 4 Combustion air supply means 5 Air preheating chamber 6 Baffle plate 7 Combustion cylinder 10 PM generator 11 Flame detector 13 Flow path 14 Flow path 15 Flow path 20 Evaluation device 21 Main header parts 22 and 23 Switching valve 24 Flow meter 25 Control valve 28 Flow meter 29 Control valve 31 Secondary air supply unit 32 Exhaust gas purification device 33 Temperature detector 131 Fuel 132 Combustion air 133 PM containing gas 151 Combustion Air inlet 152 Gas outlet

Claims (14)

An apparatus for burning particulate and / or gaseous fuel in a combustion chamber to generate particulate matter (PM) in the gas,
The combustion chamber, combustion air supply means for supplying combustion air to the combustion chamber, and intermittent fuel injection capable of intermittently injecting the fuel into the combustion air supplied to the combustion chamber And a pilot burner for igniting the fuel intermittently injected into the combustion air .   The PM generator according to claim 1, wherein the intermittent fuel injection means includes an electric valve, and the fuel is intermittently injected by controlling a valve opening time and / or a valve opening interval of the electric valve.   The PM generator according to claim 1, further comprising a fuel injection pressure adjusting unit capable of changing the fuel injection pressure.   The PM generator according to claim 3, wherein the fuel injection pressure adjusting means is a means capable of changing the injection pressure once or twice or more in the middle of the fuel injection.   The PM generator according to any one of claims 1 to 4, wherein an injection pressure of the fuel is 0.1 MPa or more and 1.0 MPa or less.   The PM generation according to any one of claims 1 to 5, further comprising a fuel mixing means for mixing the liquid fuel and the gaseous fuel in advance before injection to obtain a mixed fuel when the liquid fuel and the gaseous fuel are used together. apparatus.   The PM generator according to any one of claims 1 to 6, further comprising a gas mixing unit capable of previously mixing a gas other than the fuel with the fuel before the fuel is injected.   The PM generator according to claim 7, wherein the gas other than the fuel is air.   The PM generator according to any one of claims 1 to 8, wherein a liquid fuel among the fuels is light oil or heavy oil.   The valve opening cycle of the intermittent fuel injection means is 10 to 300 msec. The PM generator according to any one of claims 1 to 9.   The ratio of the valve opening time and the valve opening cycle of the intermittent fuel injection means (duty ratio = valve opening time / valve opening cycle) is 0.05 to 0.6. PM generator.   The PM generation device according to any one of claims 1 to 11, wherein the supply destination of the gas that has generated PM is an exhaust gas purification device, and is used for evaluating the exhaust gas purification device. While comprising a plurality of PM generators according to any one of claims 1 to 12,
Control means for operating the plurality of PM generators under the same conditions, or for operating at least one PM generator under conditions different from those of other PM generators;
PM-containing gas mixing means that obtains a mixed PM-containing gas by mixing the gas that generates PM obtained by a plurality of PM generators,
An evaluation apparatus for an exhaust gas purification apparatus that evaluates the exhaust gas purification apparatus by supplying the mixed PM-containing gas to the exhaust gas purification apparatus. A method of generating PM in a gas by burning a liquid and / or gaseous fuel,
A PM generation method comprising a step of intermittently mixing the fuel into combustion air and igniting and burning with a pilot burner .

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