Method and apparatus for improving the fractionation efficiency of diesel and gasoline particulate filters

Abstract

The present application relates to methods and apparatus for improving the fractionation efficiency of diesel and gasoline particulate filters. An exhaust aftertreatment system for improving the fractionation efficiency of a diesel or gasoline particulate filter includes a particulate filter including a housing and a filter substrate located in the housing. The filter substrate is pretreated with an aqueous solution or suspension configured to decompose or evaporate in response to exposure to heat to pretreat the filter substrate.

Description

[0001] This application is a divisional application of an application with an application date of February 15, 2019, application number 201980091675.2, and invention name “Method and device for improving the classification efficiency of diesel and gasoline particulate filters”. Technical Field

[0002] The present disclosure generally relates to aftertreatment systems for use with internal combustion ("IC") engines. Background Art

[0003] An exhaust aftertreatment system is used to receive and treat exhaust gas produced by an engine. An exhaust aftertreatment system utilizes any of a number of different components to reduce the level of harmful exhaust emissions present in the exhaust gas. For example, some exhaust aftertreatment systems for diesel-powered IC engines include a selective catalytic reduction ("SCR") system that includes a catalyst configured to reduce NO in the presence of ammonia (NH3). x The aftertreatment system may also include a filter, such as a particulate filter, which is configured to remove particulate matter ("PM"), such as soot, dust, inorganic particles, etc., from the exhaust gas. Summary of the invention

[0004] Embodiments described herein generally relate to systems and methods for improving the fractionation efficiency of a diesel or gasoline particulate filter. In one or more embodiments, an exemplary particulate filter includes a housing including an inlet cone. A filter substrate is located in the housing. A predetermined amount of ash is attached to the inlet cone and is configured to be released into exhaust gas flowing through the inlet cone to pre-treat the filter substrate.

[0005] In one or more embodiments, the particulate filter further includes a binder material combined with the predetermined amount of ash to facilitate attaching the predetermined amount of ash to the inlet cone.

[0006] In one or more embodiments, the predetermined amount of ash released into the exhaust gas is configured to pre-condition the filter substrate in order to achieve a target fractional efficiency of the particulate filter.

[0007] In one or more embodiments, the predetermined amount of ash is determined based on a difference between the target fractional efficiency and an initial fractional efficiency of the particulate filter, wherein the target fractional efficiency is the fractional efficiency required to cause the exhaust gas leaving the particulate filter to have a measured particulate matter emission level below a threshold particulate matter emission level.

[0008] In one or more embodiments, each of the measured particulate matter emission level and the threshold particulate matter emission level is defined relative to a number of particles.

[0009] In one or more embodiments, the predetermined amount of ash is configured to be released from the inlet cone during a break-in period of an engine operably coupled to the exhaust aftertreatment system.

[0010] In one or more embodiments, the particulate filter is a diesel particulate filter.

[0011] In one or more embodiments, the particulate filter is a gasoline particulate filter.

[0012] In one or more embodiments, an exemplary system is an exhaust aftertreatment system including a particulate filter and an ash distributor located upstream of the particulate filter. The ash distributor is configured to release ash into the exhaust gas upstream of the particulate filter to pre-treat the particulate filter.

[0013] In one or more embodiments, the ash distributor is configured to release a predetermined amount of ash into the exhaust gas for pre-treating the particulate filter to achieve a target fractional efficiency of the particulate filter.

[0014] In one or more embodiments, the predetermined amount of ash is determined based on a difference between the target fractional efficiency and an initial fractional efficiency of the particulate filter, wherein the target fractional efficiency is the fractional efficiency required to cause the exhaust gas leaving the particulate filter to have a measured particulate matter emission level below a threshold particulate matter emission level.

[0015] In one or more embodiments, each of the measured particulate matter emission level and the threshold particulate matter emission level is defined relative to a number of particles.

[0016] In one or more embodiments, the ash distributor is configured to release ash during a break-in period of an engine operably coupled to the exhaust aftertreatment system.

[0017] In one or more embodiments, the particulate filter is a diesel particulate filter.

[0018] In one or more embodiments, the particulate filter is a gasoline particulate filter.

[0019] In one or more embodiments, the particle filter further comprises:

[0020] an intermediate exhaust component coupled to the particulate filter; and

[0021] An adhesive material is coupled to at least one of the intermediate exhaust component or the particulate filter.

[0022] In one or more embodiments, an exemplary exhaust aftertreatment system includes a particulate filter and a filter located upstream of the particulate filter. The filter is configured to release an additive material that produces ash that pre-treats the particulate filter.

[0023] In one or more embodiments, the filter is a fuel filter.

[0024] In one or more embodiments, the fuel filter is configured to release the additive material into fuel flowing through the fuel filter.

[0025] In one or more embodiments, the filter is configured to release a first amount of additive material that will produce a predetermined amount of ash to pre-treat the particulate filter to achieve a target fractional efficiency of the particulate filter.

[0026] In one or more embodiments, the predetermined amount of ash is determined based on a difference between the target fractional efficiency and an initial fractional efficiency of the particulate filter, wherein the target fractional efficiency is the fractional efficiency required to cause the exhaust gas leaving the particulate filter to have a measured particulate matter emission level below a threshold particulate matter emission level.

[0027] In one or more embodiments, each of the measured particulate matter emission level and the threshold particulate matter emission level is defined relative to a number of particles.

[0028] In one or more embodiments, the filter is configured to release the additive material during a break-in period of an engine operably coupled to the exhaust aftertreatment system.

[0029] In one or more embodiments, the particulate filter is a diesel particulate filter.

[0030] In one or more embodiments, the particulate filter is a gasoline particulate filter.

[0031] In one or more embodiments, an exemplary particulate filter includes a housing in which a filter substrate is located. The filter substrate is pretreated with an aqueous solution or suspension configured to decompose or evaporate into a predetermined amount of ash in response to exposure to heat, thereby pretreating the filter substrate.

[0032] In one or more embodiments, the predetermined amount of ash is configured to pre-condition the filter substrate to achieve a target fractional efficiency of the particulate filter.

[0033] In one or more embodiments, the predetermined amount of ash is determined based on a difference between the target fractional efficiency and an initial fractional efficiency of the particulate filter, wherein the target fractional efficiency is the fractional efficiency required to cause the exhaust gas leaving the particulate filter to have a measured particulate matter emission level below a threshold particulate matter emission level.

[0034] In one or more embodiments, each of the measured particulate matter emission level and the threshold particulate matter emission level is defined relative to a number of particles.

[0035] In one or more embodiments, the aqueous solution or suspension is configured to decompose or evaporate into the predetermined amount of ash during a break-in period of an engine operably coupled to the exhaust aftertreatment system.

[0036] In one or more embodiments, the particulate filter is a diesel particulate filter.

[0037] In one or more embodiments, the particulate filter is a gasoline particulate filter.

[0038] It should be understood that all combinations of the aforementioned concepts and the additional concepts discussed in more detail below (assuming that these concepts are not mutually inconsistent) are contemplated as part of the subject matter disclosed herein. In particular, all combinations of the claimed subject matter appearing at the end of this disclosure are contemplated as part of the subject matter disclosed herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] According to the following description and the appended claims in conjunction with the accompanying drawings, the above-mentioned features and other features of the present disclosure will become more fully apparent. It should be understood that these drawings only depict several embodiments according to the present disclosure and therefore should not be considered as limiting its scope, and the present disclosure will be described in more detail and in detail by utilizing the accompanying drawings.

[0040] Figure 1 is a graph showing the normalized distribution of PM particle count and PM particle mass as a function of PM particle diameter for exhaust gas generated by a diesel (compression ignition) engine.

[0041] Figure 2 is a flow chart illustrating an exemplary method of pre-treating a particulate filter according to an exemplary embodiment.

[0042] Figure 3 is a block diagram of a system including an engine and an exhaust aftertreatment system fluidly coupled to the engine, according to an exemplary embodiment.

[0043] Reference is made to the accompanying drawings throughout the following detailed description. In the drawings, similar symbols generally represent similar parts unless the context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It should be readily understood that the aspects of the present disclosure generally described herein and shown in the drawings may be arranged, substituted, combined, and designed in a variety of different configurations, all of which are expressly contemplated and constitute a part of the present disclosure. DETAILED DESCRIPTION

[0044] Embodiments described herein relate to exhaust aftertreatment systems and particulate filter configurations that can be used, for example, to increase the fractional efficiency (e.g., particle number filtration efficiency, filtration efficiency, etc.) of a diesel or gasoline particulate filter. These embodiments can release ash or additive materials (from which the ash is generated) into the exhaust upstream of the particulate filter.

[0045] PM Emissions Overview

[0046] PM emissions can be characterized by either mass or particle number (“PN”). PM mass refers to the total mass of PM particles emitted. Particle number refers to the total number of individual PM particles emitted.

[0047] Figure 1 1 is a graph showing the normalized distribution of PM particle number 102 and PM particle mass 104 as a function of PM particle diameter 106 for exhaust gas generated by a diesel (compression ignition) engine. Figure 1 As shown, the variation in the size of diesel PM particles presents a bimodal distribution, including "nuclei mode" particles 108 and "accumulation mode" particles 110. Nuclei mode particles 108 have a relatively small diameter of approximately 3-30 nanometers (nm). Nuclei mode particles 108 account for a small portion of the total PM mass, but account for a large portion of the total particle number. Accumulation mode particles 110 have a relatively large diameter of approximately 30-500 nanometers. Accumulation mode particles 110 account for a large portion of the total PM mass, but account for a small portion of the total PM particle number. In other words, nuclei mode particles 108 have a high particle number and low mass, while accumulation mode particles 110 have a low particle number and high mass.

[0048] Unlike PM produced by compression ignition engines, PM produced by spark ignition engines, such as engines using gasoline or other fuels (e.g., ethanol, compressed natural gas, liquid petroleum gas, etc.), is mostly small in diameter (e.g., 60-80nm). In addition, some compression ignition engines, such as non-exhaust gas recirculation (non-EGR) engines used in off-road applications, typically have high operating temperatures and high engine output NO x , which reduces PM emissions. Therefore, spark-ignition engines have historically received less attention for reducing PM emissions than compression-ignition engines.

[0049] Emission regulations have historically defined diesel PM emission limits based on mass. However, there has been a growing focus on particle number in recent times, given studies showing adverse health effects from inhaling small PM particles that make up the majority of the particle number. In fact, emission regulations in some countries and regions (such as the European Union, China, and India) define PM limits for diesel and gasoline engines based on both PM mass and particle number. Similar regulations are also being considered in the United States. Therefore, exhaust aftertreatment systems need to be designed to minimize PM emissions in terms of both mass and particle number.

[0050] Diesel engine systems typically utilize particulate filters to capture PM in order to reduce PM emissions to acceptable levels. Particulate filters for diesel engines are often referred to as diesel particulate filters ("DPF"). DPFs typically utilize porous ceramic filter media that include a large number of parallel channels. Adjacent channels are closed at each end by plugs to force the exhaust gas to flow through the porous channel walls. PM in the exhaust gas accumulates within the pores (called deep filtration) and on the surfaces of the walls (called surface filtration). Over time, PM accumulates on the surfaces of the pores and channel walls to form a "soot cake". The soot cake improves the fractionation efficiency by acting as an additional filter medium. In fact, the DPF fractionation efficiency is most often determined by the soot cake.

[0051] Some spark-ignition engine systems also utilize particulate filters to capture PM in order to reduce PM emissions to acceptable levels. For example, gasoline direct injection ("GDI") engines produce large amounts of PM (e.g., during cold starts and high-load operation). In addition, increasingly stringent inspections and management of PM particle number emissions may require the use of particulate filters on more and more types of spark-ignition engine systems. Particulate filters constructed for gasoline engines are generally referred to as gasoline particulate filters ("GPF"). Similar to DPFs, GPFs typically utilize porous ceramic filter media that include a large number of parallel channels. However, because gasoline engines produce less particulate matter than diesel engines, GPFs are less likely to form soot cakes than DPFs. Therefore, GPFs exhibit lower fractional efficiency than DPFs, particularly for filtering small PM particles that are typically dominated by soot cakes.

[0052] The soot cake is formed by PM, which includes a combination of carbonaceous soot and metallic ash captured in the particle filter. Carbonaceous soot accounts for the vast majority of PM by mass. Ash, which accounts for a relatively small amount of PM by mass, may be composed of various metallic compounds derived from lubricant additives, trace elements in the fuel, and engine wear. Ash may include inorganic crystalline particles from degraded lubricant additives (e.g., detergents, antioxidants, anti-wear compounds, etc.). Ash may include, for example, CJ4 oil (e.g., oil containing calcium, magnesium, and zinc, etc.).

[0053] During operation, the amount of PM trapped in the particulate filter increases over time. Eventually, the PM trapped in the particulate filter accumulates to a level that causes exhaust backpressure to increase to a level that results in reduced engine performance. Soot must be periodically removed by regeneration to reduce backpressure to an acceptable level. However, after regeneration, the accumulated ash remains in the filter.

[0054] Ash accumulation in a particulate filter (such as a DPF) changes the geometry (e.g., microstructure, etc.) of the filter by accumulating in the pores of the filter media, effectively reducing the pore size. The accumulated ash thus acts as additional filter media, thereby increasing the overall fractionation efficiency of the particulate filter. It has been found that even relatively low levels of ash loading (e.g., less than 2 g / L) can sufficiently increase fractionation efficiency to meet PM emission requirements.

[0055] In conventional systems, ash accumulates in the particulate filter during initial use of the engine and aftertreatment system (e.g., the break-in period). During the initial break-in period of the engine, the machined cylinder surfaces and ring surfaces of the engine conform to each other. The resulting tight seal between the cylinder and ring surfaces prevents unburned fuel and pressurized gases from leaking into the crankcase, while also preventing crankcase oil from entering the combustion chamber. During the break-in process, metallic compounds from oil consumption and engine wear can cause ash formation and ash accumulation on the particulate filter.

[0056] One challenge associated with DPFs is the ability to meet PM emission requirements during the initial use of the DPF (e.g., in a newly manufactured engine system or a newly installed DPF). The fractionation efficiency of a clean, unused DPF is relatively low until the DPF accumulates a sufficient amount of PM to form a soot cake. During initial operation, ash accumulation on the walls can also affect the geometry of the DPF and increase the fractionation efficiency. Therefore, during initial operation of the DPF, it may be difficult to meet PM emission requirements.

[0057] Embodiments of systems and methods for pre-treating a particulate filter

[0058] Various embodiments of the present disclosure relate to systems and methods for pretreating a particulate filter using ash to improve the fractional efficiency of the particulate filter. The systems and methods are used for DPFs, GPFs, and particulate filters designed for other types of fuels. It should be understood that the systems and methods described herein provide various technical advantages over existing PM filtration systems. For example, compared with existing PM filters, pretreating a particulate filter using ash by the systems and methods described herein improves the fractional efficiency of the particulate filter, particularly for small diameter PM and for the initial operating cycle of the engine system. The pretreatment systems and methods described herein significantly reduce the time required to pretreat the particulate filter. For example, by actively or passively distributing ash to the particulate filter, the fractional efficiency of the particulate filter reaches a target fractional efficiency much faster than the speed that can be achieved using conventional running-in methods. The systems and methods described herein also improve the fractional efficiency of particulate filters for spark-ignition engines, which may not be able to achieve sufficient ash accumulation through conventional running-in methods.

[0059] The amount of preloaded ash and the duration that the ash is distributed to the particulate filter depends on engine and aftertreatment component characteristics (e.g., engine displacement, expected fuel, aftertreatment system architecture, particulate filter volume, etc.). According to various embodiments, the amount of preloaded ash is determined based on a difference between an initial fractional efficiency and a target fractional efficiency of the particulate filter to precondition the particulate filter with the amount of preloaded ash. The amount of preloaded ash is distributed to the particulate filter to precondition the particulate filter.

[0060] According to various embodiments, ash can be distributed to the particle filter in various ways. For example, in some embodiments, the system includes a chemically active filter medium that is configured to release a material that causes ash (which will preload the particle filter) to be produced. The amount of additive material released corresponds to the amount required to produce the amount of preloaded ash required to pretreat the particle filter to achieve a target classification efficiency. In some embodiments, the chemically active filter medium is included in a fuel filter. The chemically active filter medium is configured to controllably release the additive material into the fuel during initial engine operation. The additive material is configured to increase the amount of ash when the fuel is burned.

[0061] In other embodiments, the chemically active filter media is included in another type of filter, such as a lubricating oil filter. For example, in some embodiments, the system includes a lubricating oil filter having a chemically active filter media. The chemically active filter media of the lubricating oil filter is configured to controllably release additive material into the lubricating oil during initial engine operation. The additive material is configured to oxidize during engine operation to produce ash that is released into the exhaust gas. The amount of additive material added to the lubricating oil is related to the ash loading rate.

[0062] In some embodiments, the exhaust aftertreatment system includes an ash distributor located upstream of the particulate filter. The ash distributor is configured to distribute ash (e.g., ash powder) and / or additive material (the additive material is configured to generate ash once distributed into the exhaust gas) into the exhaust gas during the run-in period. The amount of ash and / or additive material released into the exhaust gas corresponds to the amount required to generate the amount of pre-loaded ash required to pre-treat the particulate filter to achieve a target classification efficiency.

[0063] In some embodiments, the dispensing device is an active device configured to dispense ash and / or additive material in response to receiving a control signal. In other embodiments, the dispensing device is a passive device configured to dispense ash and / or additive material in response to exposure to certain environmental conditions (e.g., exposure to heat) rather than in response to receiving a control signal. In each embodiment, the ash is dispensed into the particulate filter so as to form a uniform distribution on the filter media.

[0064] In some embodiments, an aqueous solution is pre-applied to the particulate filter, the aqueous solution being configured to decompose or evaporate into an ash layer in response to exposure to heat. The amount (e.g., volume or mass) and / or composition of the aqueous solution corresponds to the amount required to produce the amount of pre-loaded ash required to pre-treat the particulate filter to achieve a target fractionation efficiency.

[0065] In some embodiments, the ash is deposited (e.g., bonded, adhered, etc.) onto the exhaust components prior to the break-in period so as to be released from the exhaust components during the break-in period. For example, in some embodiments, the ash dispensed into the particulate filter further includes a binder material mixed with the ash powder to facilitate attachment of the ash to the exhaust components upstream of the particulate filter or to the inlet cone of the particulate filter.

[0066] In some embodiments, the filter substrate is pre-treated with an organometallic solution. The organometallic solution is configured to dispense a predetermined amount of ash forming material into a fuel of an engine or a lubricant used by the engine such that ash is formed during a break-in period.

[0067] Figure 2 is a flow chart illustrating an exemplary method 200 of pre-treating a particulate filter according to an exemplary embodiment.

[0068] At 202, an initial fractional efficiency of a particulate filter of an exhaust aftertreatment system is determined. The fractional efficiency of a filter is the ratio of the amount of particulate matter captured by the filter medium of the filter to the amount of particulate matter entering the particulate filter. The initial fractional efficiency can be determined in various ways, such as testing the filter according to the procedures specified in ISO 29463-1. In some embodiments, an empirical model developed by the inventors is used to determine the fractional efficiency. For example, in some embodiments, the fractional efficiency is determined based on the physical properties of the filter medium, such as porosity, pore size, and wall thickness.

[0069] At 204, a target fractional efficiency for the particulate filter is determined. The target fractional efficiency is the fractional efficiency required to cause the exhaust gas exiting the particulate filter to have a measured particulate matter emission level below a threshold particulate matter emission level. As described above, the fractional efficiency is the ratio of the amount of particulate matter captured by the filter media of the filter to the amount of particulate matter entering the particulate filter. The particulate matter emission level is the amount of particulate matter exiting the particulate filter, which is the difference between the amount of particulate matter entering the particulate filter and the amount of particulate matter captured by the filter media of the filter. Therefore, the target fractional efficiency is determined by dividing the difference between the amount of particulate matter entering the particulate filter and the threshold particulate matter level by the amount of particulate matter entering the particulate filter.

[0070] At 206, the amount of pre-loaded ash to be released onto the particulate filter is determined based on the difference between the target fractional efficiency and the initial fractional efficiency. The target fractional efficiency is a required minimum fractional efficiency (e.g., required by regulations, etc.). The target fractional efficiency may be a function of the engine, filter, and other requirements (e.g., certification requirements, local regulatory requirements, etc.). The amount of pre-loaded ash may be determined by measuring the particle number efficiency of the particulate filter with no ash (e.g., at 0 ash loading, etc.), an ash loading of 0.1 gm / L, an ash loading of 0.5 gm / L, and an ash loading of 1 gm / L, and determining the amount of pre-loaded ash using a correlation (e.g., a linear correlation, a best fit curve, etc.) between these measurements and the target fractional efficiency.

[0071] At 208 , the ash is distributed to the particulate filter to pre-treat the particulate filter.

[0072] At 210, it is determined whether the amount of ash dispensed into the particulate filter is less than the amount of pre-loaded ash determined at 206. If the result of 210 is "yes", dispensing of ash continues at 208. If the result of 210 is "no", meaning that the amount of pre-loaded ash has been dispensed into the particulate filter, dispensing of ash is stopped at 212.

[0073] Figure 3 is a block diagram of a system 300 according to an exemplary embodiment, the system 300 including an engine 302 and an exhaust aftertreatment system 304 fluidly coupled to an exhaust manifold (not shown) of the engine 302. The engine 302 may be a compression ignition or spark ignition engine, and may be powered by any of a variety of fuels (e.g., diesel, natural gas, gasoline, etc.). In one embodiment, the engine 302 is a diesel or lean burn gasoline engine. In operation, the engine 302 exhausts exhaust gas, which flows downstream from the engine 302 through the exhaust aftertreatment system 304. In general, the exhaust aftertreatment system 304 is configured to remove various chemical and particulate emissions present in the exhaust gas.

[0074] The exhaust aftertreatment system 304 includes an exhaust passage 306 and a particulate filter 308. The exhaust passage 306 is in fluid communication with the engine 302 to receive the exhaust gas. The particulate filter 308 is operably coupled to the exhaust passage 306 (e.g., positioned along the exhaust passage 306) so that the particulate filter 308 is in fluid communication with the engine 302 and will receive the exhaust gas via the exhaust passage 306. The particulate filter 308 is configured to remove PM (e.g., soot, dust, inorganic particles, etc.) from the exhaust gas (exhaust gas received from the engine 302).

[0075] The particulate filter 308 may include an inlet cone 310 and an outlet cone 312. The inlet cone 310 is located at the upstream end of the particulate filter 308, and the outlet cone 312 is located at the downstream end of the particulate filter 308. It should be understood that the terms "upstream" and "downstream" as used herein are defined relative to the flow direction of exhaust gas from the engine 302 and through the exhaust passage 306.

[0076] Various structures, devices, etc. may be provided to pre-treat the particulate filter 308 with ash in order to improve the fractionation efficiency of the particulate filter. It should be understood that according to various embodiments, the particulate filter 308 may be pre-treated with ash in various ways. The amount of pre-loaded ash and the duration for which the ash is distributed to the particulate filter 308 depend on the characteristics of the engine 302, the particulate filter 308, and the entire exhaust aftertreatment system 304 (e.g., engine displacement, expected fuel, aftertreatment system configuration, particulate filter volume, etc.). According to various embodiments, the amount of pre-loaded ash used to pre-treat the particulate filter 308 is determined based on the difference between the initial fractionation efficiency and the target fractionation efficiency of the particulate filter. For example, the amount of pre-loaded ash is determined by Figure 2 The amount of pre-loaded ash is distributed to the particulate filter 308 to pre-treat the particulate filter 308.

[0077] In one embodiment of the exhaust aftertreatment system 304, the particulate filter 308 can be pretreated with ash by an ash distributor 314 including an ash powder 316. The ash distributor 314 is configured to distribute the ash powder 316 into the exhaust gas upstream of the particulate filter 308. When distributed into the exhaust gas, the ash powder 316 is dispersed in the exhaust gas and flows into the particulate filter 308 so as to pretreat the particulate filter 308 with the evenly distributed ash powder 316. According to various embodiments, the ash distributor 314 includes a piezoelectric valve configured to controllably distribute the amount of the desired ash powder 316. In other embodiments, the ash distributor 314 includes another type of valve known to those skilled in the art for automotive exhaust aftertreatment systems. In some embodiments, the ash distributor 314 is an aerosol sprayer, and the ash powder 316 is an aerosol (e.g., a suspension of fine particles, etc.). The aerosol can be generated by sieving, and the size of the particles in the aerosol can be controlled by a screen used for sieving.

[0078] Ash powder 316 can be produced by a commercial process that does not involve the operation of an internal combustion engine (e.g., engine 302, etc.). For example, ash powder 316 can be produced by a combustion process. The combustion process can utilize burner equipment (e.g., diesel particulate generator (DPG), diesel particulate filter test system, diesel particulate filter cleaning system, etc.) to produce ash powder 316. The burner equipment can be large-scale so that ash powder 316 can be produced quickly and cheaply. In other examples, ash powder 316 can be produced by a chemical process. This chemical process may involve chemicals such as calcium sulfate (CaSO4) (such as calcium sulfate powder, etc.), oils (such as motor oil, lubricating oil, etc.), and / or solid media. Ash powder 316 can also be produced by an aging process (e.g., laboratory aging process, etc.).

[0079] In some embodiments where system 300 includes ash distributor 314, system 300 does not include filter 318 or additive material 320. Similarly, in some embodiments where system 300 includes filter 318, system 300 does not include ash distributor 314 or ash powder 316.

[0080] In some embodiments, the exhaust aftertreatment system 304 includes a controller 317, which is electrically or communicatively coupled to the ash distributor 314. The controller 317 is configured to control the ash distributor 314 to distribute the desired amount of ash powder 316 into the exhaust passage 306. The controller 317 may include a microprocessor, an application specific integrated circuit ("ASIC"), a field programmable gate array ("FPGA"), etc. or a combination thereof. The controller 317 may include a memory, which may include, but is not limited to, an electronic memory, an optical memory, a magnetic memory, or any other storage or transmission device capable of providing program instructions to a processor, an ASIC, an FPGA, etc. The memory may include a memory chip, an electrically erasable programmable read-only memory ("EEPROM"), an erasable programmable read-only memory ("EPROM"), a flash memory, or any other suitable memory from which the controller 317 can read instructions. The instructions may include code from any suitable programming language.

[0081] In one embodiment of the system 300, the particulate filter 308 can be pre-treated with ash via a filter 318 configured to release an additive material 320 that generates the ash to pre-load the particulate filter 308. The filter 318 includes a chemically active filter media configured to release the additive material 320 in response to exposure of the chemically active filter media to a fluid.

[0082] In some embodiments, filter 318 is a fuel filter located in the fuel used by engine 302. Filter 318 includes a housing containing a chemically active filter medium that is configured to controllably release additive material 320 into the fuel during initial operation of engine 302. Additive material 320 is configured to produce an increased amount of ash when the fuel is combusted in engine 302. Filter 318 is configured so that the amount of additive material 320 it releases into the fuel (e.g., the rate at which additive material 320 is metered into the fuel, etc.) corresponds to the amount of pre-loaded ash required to produce the pre-treatment particulate filter to achieve a target fractionation efficiency (e.g., the rate at which ash is loaded onto particulate filter 318, etc.). In some embodiments, filter 318 is another type of filter, such as a lubricating oil filter, a hydraulic oil filter, a coolant filter, a DPF filter, or another type of filter.

[0083] When ash is loaded onto the particulate filter 318 (e.g., when the ash distributor 314 distributes ash powder 316 into the exhaust gas upstream of the particulate filter 308, when the additive material 320 is dosed into the fuel and the fuel is directed through the engine 302, etc.), the operation of the engine 302 can be carefully controlled (e.g., changes in the output shaft speed of the engine 302 are minimized, changes in the fuel consumption of the engine 302 are minimized, changes in the throttle position of the engine 302 are minimized, etc.) to provide optimal distribution of ash loaded onto the particulate filter 318 (e.g., preventing uneven loading of ash onto the particulate filter 318, etc.).

[0084] In some embodiments of the exhaust aftertreatment system 304, the particulate filter 308 may be pre-treated with ash by an exhaust component 322 located upstream of the particulate filter 308. The exhaust component 322 includes a combination of ash and a binder material 324 attached to an inner surface of the exhaust component 322. The combined ash and binder material 324 is configured such that the binder material will release ash from the exhaust component 322 in response to exposure to exhaust gas above a predetermined temperature, thereby pre-loading the particulate filter 308 with a predetermined amount of ash.

[0085] In some embodiments, a combined ash and binder material 324 is attached to the inlet cone 310 of the particulate filter 308. In a similar manner as described above with respect to the exhaust component 322, the combined ash and binder material 324 is configured to be released from the inlet cone 310 in response to exposure to exhaust gases above a predetermined temperature so as to pre-load the particulate filter 308 with a predetermined amount of ash.

[0086] In some embodiments, the combined ash and binder material 324 is attached to an intermediate exhaust conduit 325. The intermediate exhaust conduit 325 is located between the exhaust component 322 and the particulate filter 308. The ash distributor 314 is coupled to the intermediate exhaust conduit 325. The combined ash and binder material 324 can be attached to the intermediate exhaust conduit 325 upstream and / or downstream of the ash distributor 314.

[0087] In some embodiments, the combined ash and binder material 324 is attached to an inner surface of an upstream exhaust component 326. The upstream exhaust component 326 may be part of an exhaust duct, an exhaust manifold, an exhaust port, or a turbocharger assembly (e.g., a turbine, etc.). In such embodiments, the combined ash and binder material 324 is configured to be released from the upstream exhaust component 326 in response to a temperature above a threshold. The combined ash and binder material 324 is heated by interaction with the engine 302 (e.g., by conduction, etc.) and by interaction with the exhaust gas (e.g., by convection, by conduction, etc.).

[0088] In some embodiments, the particle filter 308 includes an aqueous solution or suspension pre-applied thereto. The aqueous solution is configured to decompose or evaporate into a layer of ash in response to exposure to heat. The amount (e.g., volume or mass) and / or composition of the aqueous solution or suspension corresponds to the amount required to produce the amount of pre-loaded ash required to pre-treat the particle filter 308 to achieve a target fractionation efficiency.

[0089] Although the ash distributor 314, filter 318 and combined ash and binder material 324 are Figure 3 , but it should be understood that embodiments may be constructed in which only one or two of them may be included to produce ash for use in pretreatment.

[0090] The term "controller" includes all kinds of devices, equipment and machines for processing data, including, for example, a programmable processor, a computer, a system on a single chip or multiple chips, a portion of a programmable processor, or a combination of the above. The device may include a dedicated logic circuit (e.g., an FPGA or ASIC). In addition to hardware, the device may also include code that creates an execution environment for the computer program in question, for example, code that builds processor firmware, a protocol stack, a database management system, an operating system, a cross-platform operating environment, a virtual machine, or one or more combinations thereof. The device and the executed environment can implement the infrastructure of various different computing models, such as a distributed computing infrastructure and a grid computing infrastructure.

[0091] A computer program (also referred to as a program, software, software application, script, or code) may be written in any form of programming language, including compiled or interpreted languages, declarative or procedural languages, and it may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, object, or other unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program may be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files storing one or more modules, subroutines, or portions of code).

[0092] As used herein, the term "coupled" and similar terms refer to the direct or indirect joining of two components to one another. Such joining may be stationary (e.g., permanent) or movable (e.g., removable or releasable). Such joining may be achieved by the two components or the two components and any additional intermediate components being integrally formed as a single unitary body with one another, or by the two components being attached to one another or the two components and any additional intermediate components being attached to one another.

[0093] It is important to note that the construction and arrangement of the various exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in the present disclosure, those skilled in the art who review the present disclosure will readily recognize that many modifications (e.g., changes in the size, dimensions, structure, shape and proportion of various elements, the value of parameters, mounting arrangements, use of materials, colors, orientations, etc.) are possible without substantially departing from the novel teachings and advantages of the subject matter described herein. In addition, it should be understood that, as will be understood by those of ordinary skill in the art, features from one embodiment disclosed herein may be combined with features of other embodiments disclosed herein. Other substitutions, modifications, changes, and omissions may also be made in the design, operating conditions, and arrangement of the various exemplary embodiments without departing from the scope of the present invention.

[0094] Although this specification contains many specific implementation details, these should not be interpreted as limiting the scope of any invention or that can be claimed, but rather as a description of the features of a specific implementation for a specific invention. Certain features described in this specification in the context of separate embodiments may also be implemented in a single embodiment in combination. Conversely, the individual features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. In addition, although features may be described above as working in certain combinations and even initially claimed as such, one or more features from the claimed combination may be deleted from the combination in some cases, and the claimed combination may involve a sub-combination or a variation of the sub-combination.

Claims

1. An exhaust gas aftertreatment system for being operably connected to an engine, the exhaust gas aftertreatment system comprising: Particle filter; an ash distributor coupled to the exhaust conduit upstream of the particulate filter, the ash distributor being configured to release a predetermined amount of ash into exhaust gas generated by the engine in order to pre-treat the particulate filter; and A controller is configured to maintain an operating parameter of the engine constant while the ash dispenser releases the predetermined amount of ash.

2. The exhaust gas aftertreatment system according to claim 1, wherein: The predetermined amount of ash is sufficient to achieve a target classification efficiency of the particulate filter.

3. The exhaust gas aftertreatment system according to claim 2, wherein: The predetermined amount of ash is determined based on a difference between the target fractional efficiency required to cause exhaust gas exiting the particulate filter to have a measured particulate matter emission level below a threshold particulate matter emission level and an initial fractional efficiency of the particulate filter.

4. The exhaust gas aftertreatment system according to claim 3, wherein: The measured particulate matter emission level and the threshold particulate matter emission level are each defined relative to a particle number.

5. The exhaust gas aftertreatment system according to claim 1, wherein: The ash distributor releases the predetermined amount of ash during a break-in period of the engine.

6. The exhaust gas aftertreatment system according to claim 1, wherein: The particle filter is a diesel particle filter.

7. The exhaust gas aftertreatment system according to claim 1, wherein: The particle filter is a gasoline particle filter.

8. The exhaust gas aftertreatment system according to claim 1, further comprising: an intermediate exhaust component coupled to the exhaust conduit upstream of the particulate filter; and An adhesive material is coupled to at least one of the intermediate exhaust component or the particulate filter.

9. The exhaust gas aftertreatment system according to claim 1, wherein: The ash dispenser is an aerosol sprayer; and The ash is an aerosol.

10. The exhaust gas aftertreatment system according to claim 1, further comprising: an exhaust component positioned upstream of the particulate filter; and An ash binder material is attached to the inner surface of the exhaust component.

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