Patent Application
20070000242
The present disclosure is directed to a regeneration assembly and, more particularly, to a regeneration assembly configured to increase the temperature of exhaust gases directed to a particulate trap.
Engines, including diesel engines, gasoline engines, natural gas engines, and other engines known in the art, may exhaust a complex mixture of air pollutants. The air pollutants may be composed of both gaseous and solid material, such as, for example, particulate matter. Particulate matter may include ash and unburned carbon particles called soot.
Due to increased environmental concerns, some engine manufacturers have developed systems to treat engine exhaust after it leaves the engine. Some of these systems employ exhaust treatment devices such as particulate traps to remove particulate matter from the exhaust flow. A particulate traps may include filter material designed to capture particulate matter. After an extended period of use, however, the filter material may become partially saturated with particulate matter, thereby hindering the particulate trap's ability to capture particulates.
The collected particulate matter may be removed from the filter material through a process called regeneration. A particulate trap may be regenerated by increasing the temperature of the filter material and the trapped particulate matter above the combustion temperature of the particulate matter, thereby burning away the collected particulate matter. This increase in temperature may be effectuated by various means. For example, some systems may employ a heating element to directly heat one or more portions of the particulate trap (e.g., the filter material or the external housing). Other systems have been configured to heat exhaust gases upstream of the particulate trap. The heated gases then flow through the particulate trap and transfer heat to the filter material and captured particulate matter. Such systems may alter one or more engine operating parameters, such as the ratio of air to fuel in the combustion chambers, to produce exhaust gases with an elevated temperature. Alternatively, such systems may heat the exhaust gases upstream of the particulate trap with, for example, a burner disposed within an exhaust conduit leading to the particulate trap.
One such system is disclosed by U.S. Pat. No. 4,651,524, issued to Brighton on Mar. 24, 1987 (“the '524 patent”). The '524 patent discloses an exhaust treatment system configured to increase the temperature of exhaust gases with a burner.
While the system of the '524 patent may increase the temperature of the particulate trap, the regeneration device of the '524 patent is not configured such that a portion of the device may be useable with other engine specific portions of the device having different sizes and shapes. Moreover, the regeneration device described therein may be too large to be installed as part of an engine package. As a result, it may be difficult to accurately calibrate the regeneration device and the engine system together as a unit.
The disclosed regeneration assembly is directed toward overcoming one or more of the problems set forth above.
In one exemplary embodiment of the present disclosure, a regeneration assembly includes a first portion having a combustion chamber connected to a combustor head. The regeneration assembly also includes a second portion including a housing. The first portion is removably connectable to the second portion.
In another exemplary embodiment of the present disclosure, a regeneration assembly includes a universal first portion including a combustion chamber connected to a combustor head. The combustion chamber defines a first combustion zone. The regeneration assembly also includes a second portion having a housing defining a second combustion zone. The combustion chamber of the universal first portion is disposed substantially within the housing. The first combustion zone is substantially isolated from the second combustion zone by a stabilizer connected to the combustion chamber.
In still another exemplary embodiment of the present disclosure, a method of regenerating a filter using a regeneration assembly includes injecting a flow of a combustible substance into a first combustion zone of the regeneration assembly, directing a flow of oxygen to the first combustion zone of the regeneration assembly, and partially combusting the combustible substance in the first combustion zone. The method also includes directing a flow of exhaust to a second combustion zone of the regeneration assembly and substantially completely combusting a remainder of the injected flow of the combustible substance in the second combustion zone.
As shown in
The combustor head 16 may be, for example, a manifold, a cap, and/or any other structure capable of supporting components of a regeneration assembly. As shown in
As shown in
The combustion chamber 18 may be connected to the combustor head 16 and may be fluidly connected to any fluid passages or channels (not shown) of the combustor head 16 such that a gas entering the gas inlet 28 of the combustor head 16 may be directed to the combustion chamber 18. The combustion chamber 18 may be made of any high temperature corrosion resistant alloy known in the art such as, for example, Hastelloy®. Alternatively, the combustion chamber may be made of any of the metals and/or alloys mentioned above with respect to the combustor head 16. The combustion chamber 18 may be any size, shape, and/or configuration known in the art. As shown in
The igniter 20 may be any device capable of igniting a combustible substance. In an exemplary embodiment of the present disclosure, the igniter 20 may include, for example, a spark plug, glow plug, plasma igniter, surface-type igniter, and/or any other ignition device known in the art. The type of igniter 20 used may depend on a variety of factors, including, for example, the desired speed and/or reliability with which the igniter 20 may ignite a combustible substance during use, the duration of ignitor firing, and the space limitations of the combustor head 16. The igniter 20 may be formed from materials resistant to, for example, fouling due to carbon deposits being formed on an electrode (not shown) of the igniter 20. The igniter 20 may be configured to ignite a combustible substance proximate the combustion chamber 18. The igniter 20 may also be configured to fire periodically to ignite the combustible substance being delivered to the combustion chamber 18 and may be configured to fire substantially continuously to assist in stabilizing the combustion process. It is understood that assisting in stabilizing the combustion process may include keeping a combustion flame burning with a substantially consistent intensity.
The injector 22 may be disposed within the combustor head 16 and may be configured to deliver a combustible substance to the combustion chamber 18. The injector 22 may be, for example, a pressure swirl, air assist, air blast, dual orifice, and/or any other type of injector known in the art. The injector 22 may include, for example, a nozzle, a fluid atomization device, and/or any other device capable of injecting and/or atomizing an injected fluid. In an exemplary embodiment, an end of the injector 22 may define a plurality of holes sized, positioned, and/or otherwise configured to facilitate the formation of a relatively fine mist and/or spray of injected fluid. The injector 22 may be configured to substantially evenly distribute the combustible substance within the combustion chamber 18. The injector 22 may also be configured to distribute the combustible substance at a desired angle within the combustion chamber 18.
In an exemplary embodiment, the injector 22 may be a dual orifice nozzle configured to controllably deliver two separate flows of fluid. As illustrated in
The combustor head 16 may also include a coolant inlet 60 and a coolant outlet 68 proximate the injector 22. As illustrated in
As illustrated in
Referring again to
It is understood that the circular motion of gas created by the swirler 24 may assist in mixing a combustible substance with a flow of gas. It is also understood that the swirling motion of the gas created by the swirler 24 may assist in directing a portion of the combustible substance delivered by the injector 22 to a wall of the combustion chamber 18. This motion may assist in accelerating the evaporation of fuel collected at the combustion chamber wall. Thus, the swirler 24 may assist in maintaining the temperature of the combustion chamber wall within desired limits. Such desired limits may correspond to the melting point of the combustion chamber wall. The motion of gas created by the swirler 24 may also result in a recirculation of hot combustion products back into a first combustion zone 40 defined by the combustion chamber 18. Recirculating products of the combustion process may assist in sustaining and/or stabilizing the combustion process.
As shown in
As discussed above, the housing 30 may be connected to the combustor head 16 such that the combustion chamber 18 may be disposed substantially within, and fluidly connected to, the housing 30. The housing 30 may be formed of any of the materials discussed above. The housing 30 may also be formed from, for example, a high silicone steel casting or other conventional high temperature material useful in combustion environments. The housing 30 may have any shape and/or configuration useful in minimizing restrictions on a flow of fluid through the housing 30, and/or minimizing the pressure drop experienced by the flow as it passes therethru.
The housing 30 may be long enough to substantially completely contain a flame created by the ignitor 20 and the injector 22 during a combustion reaction. As shown in
As mentioned above, the first portion 12 may be a universal component of the regeneration assembly 10. In an exemplary embodiment, a single combustor head 16/combustion chamber 18 assembly of the present disclosure may be sized and/or otherwise configured to connect to different housings 30 having different sizes, shapes and other configurations. In such an embodiment, each different housing 30 may be particularly fitted to conform to the power source 44 to which it is connected based on size and/or space constraints. It is understood that a portion of each different housing 30 may have substantially similar dimensions such that the universal combustor head 16 may connect thereto and the universal combustion chamber 18 may be disposed therein when the combustor head 16 is connected to the housing 30.
As discussed above, the housing 30 may assist in defining the second combustion zone 38 downstream of the combustion chamber 18. The housing 30 may also include the exhaust inlet 32 and an outlet 34. A portion of a diagnostic device 36 may be disposed within the housing 30 and configured to sense characteristics of a flow passing therethru. In an exemplary embodiment, the diagnostic device 36 may be disposed proximate the outlet 34 and/or the exhaust inlet 32 of the housing 30. The diagnostic device 36 may be, for example, a temperature, flow sensor, particulate sensor, and/or any other conventional sensor known in the art. The diagnostic device 36 may also be electrically connected to the controller (
The disclosed regeneration assembly 10 may be used to assist in purging contaminants collected within filters through regeneration. Such filters may include any type of filters known in the art such as, for example, particulate filters useful in extracting pollutants from a flow of liquid. Such filters, and thus, the regeneration assembly 10, may be fluidly connected to an exhaust outlet of, for example, a diesel engine or other power source 44 known in the art. The power source 44 may be used in any conventional application where a supply of power is required. For example, the power source 44 may be used to supply power to stationary equipment such as power generators, or other mobile equipment, such as vehicles. Such vehicles may include, for example, automobiles, work machines (including those for on-road, as well as off-road use), and other heavy equipment.
The regeneration assembly 10 may be configured to raise the temperature of a flow of exhaust passing through it without undesirably restricting the flow. With minimal flow restriction, the regeneration assembly 10 may avoid creating backpressure within an exhaust conduit upstream of the regeneration assembly 10 and/or otherwise inhibiting power source performance. Further, the regeneration assembly 10 may be configured to generate an output flow at the outlet 34 with a desired elevated temperature. The regeneration assembly 10 may also be small enough to be packaged on the power source 44. As a result, the regeneration assembly 10 may be easily calibrated with the power source 44 by the power source manufacturer. The operation of the regeneration assembly 10 will now be described in detail with respect to
A flow of exhaust produced by the power source 44 may pass from the power source 44, through the energy extraction assembly 42, and into the regeneration device 10 through the exhaust inlet 32. It is understood that in an exemplary embodiment of the present disclosure, the energy extraction assembly may be omitted. Under normal power source operating conditions, the regeneration assembly 10 may be deactivated and the flow of exhaust may pass through the outlet 34 and through a particulate filter 50 where a portion of the pollutants carried by the exhaust may be captured. Over time, however, the filter 50 may become saturated with collected pollutants, thereby hindering its ability to remove pollutants from the flow of exhaust. A diagnostic device 48 configured to sense characteristics of the filtered flow and/or the filter 50 may be fluidly connected to the filter 50 and may be electrically connected to the controller 46. The diagnostic device 48 may detect, for example, filter temperature, flow rate, flow temperature, filtered flow particulate content, and/or other characteristics of the filter 50 and/or the flow. The diagnostic device 48 may send this information to the controller 46 and the controller 46 may use the information to determine when the filter 50 requires regeneration. As illustrated by the dashed lines in
To begin operating the regeneration assembly 10, the controller 46 may at least partially open a mixing valve 58 to permit a small amount of additional gas into the regeneration assembly 10 through the gas inlet 28. The gas may be a flow of ambient air 54 containing, among other things, oxygen. The gas may also include a flow of filtered exhaust 56 extracted from downstream of the filter 50 and directed through the mixing valve 58. The gas may further include a flow of compressed air 55 directed to the regeneration assembly 10 from, for example, a compressor assembly (not shown) or the intake manifold 74 of the power source 44. The controller 46 may also activate the ignitor to create, for example, a spark proximate the combustion chamber 18. The controller 46 may at least partially open the supply valve 21, thereby directing a flow of a combustible substance from the combustible substance source 62 to the injector 22. As discussed above, in an embodiment of the present disclosure, the controller 46 may also at least partially open the pilot control valve 13 and/or the secondary control valve 11 to assist in controlling the flow of the combustible substance. It is understood that the combustible substance may be, for example, gasoline, diesel fuel, reformate, or any other conventional combustible fluid. Hereinafter, the combustible substance will be referred to as fuel.
The swirler 24 (
The controller 46 may control the amount of fuel injected based on the desired temperature required for regeneration. It is understood that as more fuel is injected, the temperature of the flow exiting the outlet 34 will increase. The controller 46 may also control the relative amount of gas supplied to the gas inlet 28 based on the amount of fuel injected and the desired temperature. The desired temperature may be, for example, the temperature of the exhaust flow at the outlet 34 of the regeneration assembly 10 causing the filter 50 to regenerate at a desired rate or within a desired time. It is understood that such desired temperatures may be greater than approximately 500° Celsius.
Once the desired temperature has been reached, the filter 50 may begin to regenerate and the materials collected therein may begin to burn away. The regeneration assembly 10 may continue to combust fuel until the filter 50 has been satisfactorily regenerated. During regeneration, coolant may be supplied to the combustor head 16 to cool a portion of the combustor head 16 proximate the injector 22.
After the controller 46 determines regeneration is complete, the supply of fuel and gas to the regeneration assembly 10 may cease, and the ignitor 20 may be deactivated. The controller 46 may also direct a flow of purge gas from the intake manifold 74 of the power source 44 to the injector 22. This flow of purge gas may purge the injector 22 of any remaining fuel contained therein and may assist in minimizing, for example, the amount of carbon build-up in the injector 22 resulting therefrom.
It will be apparent to those having ordinary skill in the art that various modifications and variations can be made to the disclosed regeneration assembly 10 without departing from the scope of the invention. Other embodiments of the invention will be apparent to those having ordinary skill in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the invention being indicated by the following claims and their equivalents.
