The present disclosure relates generally to a system and method for cleaning the flow paths of a heat exchanger, and more particularly to a system and method for cleaning out the flow paths of an exhaust gas recirculation (EGR) cooler, wherein the method includes increasing the velocity of gas passing through the EGR cooler to shear hydrocarbons and soot off of the EGR cooler flow path surfaces.
NOx and O3 emissions are produced by excessively high temperatures that are present during combustion within diesel engines. Exhaust gas recirculation (EGR) systems reduce the production of NOx and O3 emissions at least in part by lowering the combustion temperature of the diesel fuel. This is accomplished at least in part by recirculating a portion of the exhaust gas from the engine back into the engine. The recirculated exhaust gas effectively dilutes the diesel/air mixture, which lowers the combustion temperature.
Heat exchangers include multiple internal flow paths for the passage of fluids, wherein the flow paths are arranged so that the fluids passing therethrough are in mutual thermal contact thereby allowing heat transfer between the fluids. Build-up of extraneous matter on any of the internal flow paths within a heat exchanger can reduce the rate of heat transfer. Build-up that is severe enough to form even a partial blockage within a flow path can further reduce the heat transfer rate or even render the heat exchanger effectively inoperable. In the case of a diesel engine, passing the recirculated exhaust gas through a heat exchanger, for example an exhaust gas recirculation (EGR) cooler, provides further lowering of the combustion temperature to further reduce the production of NOx and O3 emissions. Unfortunately, gas flow paths through such an EGR cooler are prone to a build-up of hydrocarbons and soot from the exhaust gas, to the point of causing a flow restriction through the EGR cooler that renders the EGR cooler effectively inoperable. A method for cleaning out build-up within a heat exchanger, for example hydrocarbon and soot buildup within an EGR cooler, is thus needed.
In one aspect of the invention, a heat exchanger cooling system comprises an engine, an engine intake conduit, an engine exhaust port, and an exhaust gas recirculation (EGR) cooler having a cooler inlet in fluid communication with the engine exhaust port, a cooler outlet in fluid communication with the engine intake conduit, and an EGR valve disposed in fluid communication with and between the engine exhaust port and the EGR cooler. A first pressure sensor is disposed in fluid communication with and between the engine exhaust port and the EGR valve, and a second pressure sensor is disposed in the engine intake conduit. A controller is in electrical communication with the EGR valve, the first pressure sensor, and the second pressure sensor, wherein the controller is configured to implement a predetermined set of operating parameters for the engine and/or the EGR valve, wherein implementation of the predetermined set of operating parameters causes an increased flow velocity of exhaust gas through the EGR cooler.
In another aspect of the invention, a heat exchanger cooling system comprises an engine, an engine intake conduit having an intake throttle valve disposed therein, an engine exhaust port, and an exhaust manifold having a single inlet conduit and two outlet paths, wherein the single inlet conduit connects to the engine exhaust port, wherein a first path of the two outlet paths includes a thermal management valve disposed therein, and wherein a second path of the two outlet paths includes an exhaust gas recirculation (EGR) valve disposed therein. An EGR cooler includes a cooler inlet in fluid communication with the EGR valve and a cooler outlet in fluid communication with the intake throttle valve. A first pressure sensor is disposed in the first path upstream of the thermal management valve, a second pressure sensor is disposed in the second path upstream of the EGR valve, and a third pressure sensor is disposed in the engine intake conduit upstream of the intake throttle valve. A controller is in electrical communication with the EGR valve, the thermal management valve, the intake throttle valve, the first pressure sensor, the second pressure sensor, and the third pressure sensor, wherein the controller is configured to implement a predetermined set of operating parameters for the engine, the EGR valve, the thermal management valve, and/or the intake throttle valve, wherein implementation of the predetermined set of operating parameters causes an increased flow velocity of exhaust gas through the EGR cooler.
In a further aspect of the invention, a heat exchanger cooling system comprises an engine, an engine intake conduit having an intake throttle valve disposed therein, an engine exhaust port, and an exhaust manifold having a single inlet conduit and two outlet paths, wherein the single inlet conduit connects to the engine exhaust port, wherein a first path of the two outlet paths includes a thermal management valve disposed therein, and wherein a second path of the two outlet paths includes an exhaust gas recirculation (EGR) valve disposed therein. An EGR cooler includes a cooler inlet in fluid communication with the EGR valve and a cooler outlet in fluid communication with the intake throttle valve. A variable geometry turbocharger is disposed within the HECS so that a compressor side of the turbocharger is disposed in the intake conduit upstream of the intake throttle valve and a turbine side of the turbocharger is disposed in the first path, wherein the turbine side of the turbocharger includes vanes that are adjustable to control the amount of exhaust gas that flows through the turbine side. A first pressure sensor is disposed in the first path upstream of the thermal management valve, a second pressure sensor is disposed in the second path upstream of the EGR valve, and a third pressure sensor is disposed in the engine intake conduit upstream of the intake throttle valve. A controller is in electrical communication with the EGR valve, the thermal management valve, the intake throttle valve, the first pressure sensor, the second pressure sensor, and the third pressure sensor, wherein the controller is configured to implement a predetermined set of operating parameters for the engine, the EGR valve, the thermal management valve, the vanes of the turbine side of the turbocharger, and/or the intake throttle valve, wherein implementation of the predetermined set of operating parameters causes an increased flow velocity of exhaust gas through the EGR cooler.
The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. These drawings depict only several embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope.
In the following detailed description, various embodiments are described with reference to the appended drawings. The skilled person will understand that the accompanying drawings are schematic and simplified for clarity. Like reference numerals refer to like elements or components throughout. Like elements or components will therefore not necessarily be described in detail with respect to each figure.
Modern diesel engines typically include some sort of diesel particulate filter (DPF) that is designed to capture and eliminate particulates resulting from diesel combustion before the particulates are exhausted to the environment. A DPF typically requires periodic cleaning to clear out the particulates and keep the DPF operating within normal parameters. Regeneration is a known process by which the DPF is cleaned, whereby exhaust gas temperatures are raised to burn off the particulate matter to eliminate it from the DPF. An exemplary regeneration cycle includes an injection of atomized fuel into the engine (known as in-cylinder dosing) or into the exhaust stream (known as down-stream injection) to increase exhaust gas temperatures to burn off and eliminate particulates from within the DPF.
An exhaust gas recirculation (EGR) cooler disposed downstream of the exhaust side of the engine can be used to cool and divert a portion of the exhaust gas back into the engine to inhibit the production of NOx and O3 emissions. However, because the EGR cooler is downstream of the engine exhaust, soot and hydrocarbons generated during a regeneration cycle can collect within the EGR cooler, which can become problematic in causing a lowered rate of heat transfer and/or restricting the flow paths through the EGR cooler. It should be noted that a particulate filter and/or EGR cooler can be useful for use with engines other than diesel engines, for example without limitation, engines powered by gasoline, propane, or any fuel that results in the generation of hydrocarbons and soot.
Referring to
In the embodiment of the HECS 100 shown in
In the embodiment of the HECS 100 shown in
The EGR cooler 130 operates by transferring heat to the engine cooling system, which is not shown in the figures, but which is well known in the art. For example, in an embodiment exhaust gas passes through the EGR cooler 130 in thermal contact with engine coolant so that the EGR cooler 130 effectively functions as a heat exchanger by cooling the exhaust gas with the engine coolant. The engine cooling system cools the engine and the EGR cooler and sheds heat to the environment, for example, via a radiator and fan as is known in the art. Referring to
Referring to
In addition to the valves 150, 180, 190 and the pressure sensors 192, 194, 196 as described hereinabove, in an embodiment the HECS 100 further includes a controller 250. In an embodiment the controller 250 is a standalone controller including one or more microprocessors, and for example, having dedicated memory and non-volatile storage for cleaning and/or calibration control programs and stored data logs. In another embodiment the controller 250 is part of a larger vehicle controller and may also include one or more microprocessors, for example, having dedicated memory and non-volatile storage for cleaning and/or calibration control programs and stored data logs. In an embodiment the controller 250 is in electrical communication with and can receive data from and/or send actuation signals and/or power to all of the valves 150, 180190 and pressure sensors 192, 194, 196 via hardwired connections as schematically indicated by the lines connecting the controller 250 to the valves 150, 180190 and the sensors 192, 194, 196. In addition to or instead of the hardwired connections shown in
Still referring to
Still referring to
In an exemplary EGR cooler cleaning process gas flow velocity through the EGR cooler 130 is increased to velocities sufficiently high that the gas flow shears any built up layers of hydrocarbons and soot off of internal EGR cooler 130 flow path surfaces. In an embodiment the increase in gas flow velocity is controlled through a cleaning process wherein the engine 110 and one or more of the valves 150, 180, 190 are commanded by the controller 250 to operate at predetermined set-points. In an embodiment such a cleaning process is incorporated into the engine 110 control software and calibration which is stored on the controller 250, or stored elsewhere and accessed by the controller 250, where the cleaning process can be triggered manually by a user via a user interface or switch, or triggered automatically by the controller 250 at predetermined points in time and/or based upon a sensed status of the EGR cooler 130, for example, as determined by sensed pressures at one or more of the pressure sensors 192, 194, 196 indicative of a flow restriction through the EGR cooler 130.
Referring now to
Referring to
Referring to
As noted hereinabove, the apparatus and method as described herein are not exclusive to any particular type of engine and can be applied to an engine used to power a vehicle or indeed to any sort of mobile or fixed installation utilizing the engine, for example without limitation, a generator, a locomotive, a tractor, or even a spaceship.
In an exemplary heat exchanger cleaning process 300 gas flow velocity through the heat exchanger, for example, the EGR cooler 130, is increased to velocities sufficiently high that the gas flow shears any built up layers of hydrocarbons and soot off of internal EGR cooler 130 flow path surfaces. In an embodiment the increase in gas flow velocity is controlled through a cleaning process 300 wherein the engine 110 and/or one or more of the valves 150, 180, 190 are commanded by the controller 250 to operate at specific predetermined set-points. In an embodiment such a cleaning process 300 is incorporated into the engine 110 control software and calibration which is stored on the controller 250, or stored elsewhere and accessed by the controller 250, where the cleaning process 300 can be triggered manually by a user via a user interface or switch, or triggered automatically by the controller 250 at predetermined points in time and/or based upon a sensed status of the EGR cooler 130, for example, as determined by sensed pressures at one or more of the pressure sensors 192, 194, 196 indicative of a flow restriction through the EGR cooler 130.
Referring to
With respect to the use of plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. Unless otherwise noted, the use of the words “approximate,” “about,” “around,” “substantially,” etc., mean plus or minus ten percent.
A heat exchanger cleaning system and method is presented that cleans out the flow paths of a heat exchanger by creating an increased flow velocity of exhaust gas passing through the heat exchanger, wherein the increased gas velocity effectively shears off hydrocarbons and soot from the flow path surfaces of the heat exchanger. The system can be manufactured in industry for consumers and the method can be executed by consumers.
Numerous modifications to the present invention will be apparent to those skilled in the art in view of the foregoing description. It is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. Accordingly, this description is to be construed as illustrative only of the principles of the invention and is presented for the purpose of enabling those skilled in the art to make and use the invention and to teach the best mode of carrying out same. The exclusive rights to all modifications which come within the scope of the appended claims are reserved. All patents, patent publications and applications, and other references cited herein are incorporated by reference herein in their entirety.
Number | Name | Date | Kind |
---|---|---|---|
6006733 | Oleksiewicz | Dec 1999 | A |
6698409 | Kennedy et al. | Mar 2004 | B1 |
6931837 | Verkiel et al. | Aug 2005 | B2 |
6934619 | Read et al. | Aug 2005 | B2 |
6947822 | Martinez, Jr. et al. | Sep 2005 | B2 |
6955162 | Larson et al. | Oct 2005 | B2 |
6973382 | Rodriguez et al. | Dec 2005 | B2 |
6985808 | Kennedy | Jan 2006 | B1 |
7047953 | Kennedy | May 2006 | B2 |
7124582 | Kennedy | Oct 2006 | B2 |
7461627 | Liu et al. | Dec 2008 | B2 |
8010276 | Oehlerking | Aug 2011 | B2 |
8205606 | Rodriguez et al. | Jun 2012 | B2 |
8267069 | Hsia et al. | Sep 2012 | B2 |
20080098999 | Melhem et al. | May 2008 | A1 |
20110036335 | Wood et al. | Feb 2011 | A1 |
20110041816 | Hsia et al. | Feb 2011 | A1 |
20110048389 | Hsia et al. | Mar 2011 | A1 |
20110083648 | Cattani et al. | Apr 2011 | A1 |
20110100343 | Liu et al. | May 2011 | A1 |
20120323470 | Klingbeil | Dec 2012 | A1 |
20200284217 | Hakeem | Sep 2020 | A1 |