GB2530018A

GB2530018A - Catalytic exhaust gas recirculation cooler

Info

Publication number: GB2530018A
Application number: GB1415240.9A
Authority: GB
Inventors: Xu Chen; Ashok Kumar; Neal W Currier; Randall J Stafford; Ying Yuan; Changsheng Su
Original assignee: Cummins Inc
Current assignee: Cummins Inc
Priority date: 2014-08-28
Filing date: 2014-08-28
Publication date: 2016-03-16
Also published as: GB201415240D0

Abstract

A potassium glass coating 52 on the internal surfaces of the fluid passages 50 of an i.c. engine EGR cooler 40 comes into contact with the exhaust gas stream from the engine to enhance or catalyse soot oxidation thus preventing or lessening of exhaust gas cooler fouling and loss of heat transfer efficiency due to carbonaceous deposits. The potassium glass may be composed such that conversion of carbon monoxide to carbon dioxide, and of nitrogen oxide to nitrogen dioxide, is insignificant. The potassium glass may be potassium calcium silicate (K2CaSiO4, KCS, K-Ca-Silicate) which releases K+ ions in the presence of the exhaust gas stream. The potassium glass may be applied over a length D that is less than 50% of the length of the internal walls 54 of the cooler, nearer the inlet 42.

Description

CATALYTIC EXHAUST GAS RECIRCULATION COOLER

Field of the Invention:

[0001] The present disclosure generally relates to an exhaust gas cooler, and more particularly to an exhaust gas recircifiation cooler with an internal potassium glass coating that enables lower temperature soot oxidation on the internal surfaces of the cooler.

BACKGROUND

[0002] Exhaust gas recirculation (EGR) systems recirculate a portion of exhaust gas from an engine exhaust system to an engine intake system, lowering engine combustion chamber temperatures and control emissions. EGR systems typically employ an EGR cooler to lower the temperature of the recirculated exhaust gas before it is provided to the intake system. Carbonaceous deposits on the wall of the EGR cooler reduce its capacity and the efficiency of the EUR system. For example, carbonaceous deposits can restrict flow through the EGR system, preventing the desired amount of EGR being provided to the intake. These deposits can also act as insulation, preventing efficient heat transfer from the exhaust gas to the cooling mediLim in the EGR cooler, which increases the temperature of the EGR flow that is provided to the intake system. Fouling of the EGR cooler may also hinder compliance with NOx emissions standards, and negatively impacts EGR cooler sizing and engine performance. Therefore, further improvements in this technology area are needed.

SUMMARY

[0003] Unique systems, methods, and apparatus relating to a catalytic exhaust gas recirculation cooler are disclosed. A potassium glass coating on the internal surfaces of the EGR cooler comes into contact with a recirculated portion of the exhaust gas stream from an internal combustion engine to enhance soot oxidation by oxygen. The systems, methods and apparatus mitigates fouling of the EGR cooler with carbonaceous deposits on the walls of the EGR cooler, minimizing the impact of EGR cooler fouling on NOx emissions and the potential failure of the EUR cooler due to loss of heat transfer efficiency.

[0004] This summary is provided to introduce a selection of concepts that are further described herein in the illustrative embodiments. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the

following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1 is a schematic of an exemplary internal combustion engine system that includes a catalytic EGR coo'er in a high pressure EUR system.

[0006] FIG. 2 is schematic of an exemplary internal combustion engine system that inchades a cata'ytic EGR cooler in a low pressure EGR system.

[0007] FIG. 3 is a schematic of a cross section of the catalytic EGR cooler of FIGS. 1 and 2.

[0008] FIG. 4 is a graphical representation of the lower temperature soot conversion on the EGR cooler that is enabled through the use of a potassium glass coating.

DESCRIPTTON OF THE ILLUSTRATTVE EMBODIMENTS

[0009] For the purposes of promoting an understanding of the principles of the invention, reference wifi now be made to the embodiments illustrated in the drawings and specific language will he used to describe the same. It will nevertheless he understood that no limitation of the scope of the invention is thereby intended, any alterations and further modifications in the illustrated embodiments, and any further applications of the principles of the invention as illustrated therein as would normally occur to one skilled in the art to which the invention relates are contemplated herein.

[0010] One aspect of the present disclosure is directed to an apparatus such as a heat exchange vessel for an EGR cooler that includes internal surfaces defining flow passages for the recirculated exhaust gas with a potassium glass coating on the internal surfaces that comes into contact with the portion of the recirculated exhaust gas that passes through the heat exchange vessel. Another aspect of this disclosure describes a method for reducing fouling of an EGR cooler by operating an internal combustion engine including an EGR system with an EGR cooler including a coating of potassium glass on the internal surfaces of the EGR cooler that come into contact with the portion of the recirculation exhaust gas that passes through the EGR cooler. A further aspect of the present disclosure describes an engine system including an EGR system with an EGR cooler configured according to the apparatus and operable according to the methods disclosed herein.

[0011] With reference to FIG. 1, an exemplary internal combustion engine system lois shown with in internal combustion engine 12. The exemplary internal combustion engine system 10 may be provided on a vehicle powered by engine 12, which may be any type of engine understood in the art that could make use of recirculated exhaust gas in its air intake system, such as a dies& or gasoline internal combustion engine. In addition, internal combustion engine system 10 may be provided either as a stand-alone power source, ill combination with other engines, or part of a hybrid power train including an internal combustion engine for at least one of the power sources. The internal combustion engine system tO can he used for mobile applications including, hut not limited to, a vehicle, locomotive, or marine application, or for stationary applications, such as a power generation or a pumping system, for example.

[0012] Engine 12 may include a plurafity of cylinders i 4 and an intake manifold i 6 through which charge air (i.e., pressurized intake air and recirculated exhaust gas) enters the plurality of cylinders I 4from an intake system 33 and an exhaust manifokl i 8 through which exhaust gas resulting from combustion in the plurality of cylinders exits the engine to an exhaust system 39. Intake air enters internal combustion engine system 10 through turbocharger compressor 34 and may then flow through charge air cooler 32. Charge air then flows into engine 12 through the intake manifold 16. Intake valves (not shown) control the admission of charge air into cylinders 14 of the engine 12, and exhaust valves (not shown) control the outflow of exhaust gas through the exhaust manifold 18 and ultimately to the atmosphere, it being understood that not afi details of these systems that are typically present are shown. The system 10 may also include an intake throttle valve (not shown) to regulate the charge air flow to the cylinders 14 of the engine 12.

[0013] Internal combustion engine 12 produces exhaust gas from combustion which flows out of the exhaust manifold 18 to exhaust system 3, which may include a turbocharger turbine 36 and aftertreatment system 38 downstream of turbine 36. Afiertreatment system 38 may include aftertreatment devices such as one or more selective catalytic reduction (SCR) catalysts, dies& oxidation catalysts (DOC), diesel particulate filters (DPF), and/or ammonia oxidation catalysts (AMOX). in certain embodiments, one or more of the exhaust aftertreatment devices may not be present, may be provided at multiple locations andlor may he commingled. Further, any of these components may he catalyzed or not catalyzed, maybe arranged in alternate order, and/or may he provided in the same of separate housings.

[00141 The system 10 further includes a turbocharger 35 with compressor 34 operable to compress ambient air before the ambient air enters tile intake manifold lb of the engine 12 at illcreased pressure. The turbocharger 35 further illcludes turbine 36 in the exhaust system 39 and the compressor 34 in the intake system 33. A mixture of compressed air from the compressor 34 and exhaust gas from the EGR system 20 is pumped through the intake system 33, to the intake manifold 16, and finally to the cylinders 14 of the engine 12. The internal combustioll engine system 10 additionally includes a charge air cooler 32 disposed downstream of the compressor 34 in the intake system 33. The charge air cooler 32 may be an air-to-air heat exchanger, an air-to-liquid heat exchanger, or a combination of both to facilitate the transfer of thermal energy to or from the compressed air directed into the engine 12.

[0015] In certain embodiments, a wastegate (not shown) may be provided at the turbine 36 to provide an exhaust flow path that bypasses the turbine 36 in response to certain operating conditions. it is contemplated that in certain embodiments, the turbocharger 35 may not he present. It is further contemplated that in an embodiment induding the turbocharger 35, the turbocharger 35 may include a variable geometry turbine (VGT), a fixed geometry turbine, twin-turhochargers, and/or series or parallel configurations of multiple turbochargers.

[00161 The engine system further includes an EGR system 20. EUR system 20 includes an EGR conduit 28 that fluidly connects exhaust system 39 with intake system 33. The EUR system 20 also includes an EUR cooler 40 and, in certain embodiments, also may include an EGR cooler bypass line 24. When provided, an EGR cooler bypass valve 22 may be used to control how much of the recirculated exhaust gas exiting engine 12 enters the EUR cooler 40 or flows through EUR bypass line 24. Valves or other controls located in various positions may achieve the same function of controlling the portion of exhaust gas entering EUR cooler 40 or EGR bypass line 24. The EUR bypass valve 22 and its actuator, as well as many other parts of the engine system 10, may be controlled by a controller or other electronic unit (not shown.) In the illustrated embodiment. EUR bypass valve 22 is a two-way valve located in EGR cooler bypass line 24. In another embodiment, EUR cooler bypass valve 22 is located in EGR conduit 28 upstream of EUR cooler 40. In still other embodiments, EGR cooler bypass valve 22 is a three-way valve located at the junction of EGR conduit 28 and EUR cooler bypass line 24.

[0017] Additionally or alternatively, EUR system 20 may further include an EUR flow control valve 26 that may be used to control the flow of exhaust gas through the EGR conduit 28 to intake system 33. EGR flow control valve 26 is located downstream of EUR cooler 40 and upstream of intake system 33. The cooled exhaust gas exiting EGR cooler may then he combined with the cooled charge air exiting the charge air cooler 32 before the combined stream of air and exhaust gas enters engine 12 through intake manifold 16. a

[0018] Tn the embodiment shown in Fig. I, EGR system is a high pressure EGR system that connects exhaust system 39 upstream of turbine 36 to intake system 33 downstream of compressor 34. In the embodiment of Fig. 2, the EUR system 20' is a low pressure EGR system where exhaust gas to he recirculated is drawn from the exhaust gas line downstream of the turbine 36. The recirculated exhaust gas is directed through EGR cooler 40 and it joins the intake system 33 upstream of the compressor 34. In the embodiment of Fig. 2, an EGR flow control valve 21 is provided at the junction of EGR conduit 28 with exhaust system 39. FOR system intake valve 21 maybe Lised to control how much of the exhaust gas is directed into exhaust gas recirculation system 20 from exhaust system 39. It should he understood, however, that the low pressure FOR system 20' may include a bypass and/or valving arrangement such as discussed above with respect to Fig. T, and that high pressure EGR system 20 of Fig. T may include the valving arrangement discussed with respect to Fig. 2. Tn still other embodiments, a system 10 is contemplated with both high pressure and low pressure EGR systems.

[0019] The exhaust gas produce by combustion operations of engine 12 may carry different quantities of soot or carbonaceous material as it exits exhaust manifold 18.

Incomplete combustion or other factors ma)' cause soot formation during combustion of diesel or gasoline fuel in the cylinders 14 of the engine 12. Soot particles are mostly comprised of carbon, and are also referred to herein as "carbonaceous" material. Soot particles may be small initially, but they tend to clump together and adhere to various exhaust components.

[0020] Tn particular, carbonaceous material in the exhaust gases may adhere to the inner surfaces of EUR cooler 40 that define flow passages for the recirculated portion of the exhaust gas. The formation of carbonaceous deposits on the inner walls of EUR cooler 40 cause a coilditioll called "fouling" of the EGR cooler. These soot deposits and their accumulation over time reduce the capacity and efficiency of the EUR system by restricting the flow of the recircLllated exhaust gas through EGR cooler 40. This condition hinders the ahifity to provide a desired amount of EUR flow to intake system 33.

Carbonaceous deposits can also act as insulation alofig the inner walls of EGR cooler 40, preventing efficient heat transfer from the exhaust gas to the cooling medium in the EUR cooler 40. This insulation effect increases the temperature of the recirculated exhaust gas mixing with the intake air, decreasing the efficiency of combustion in the engine 12. In order to account for sLich effects, a negative impact on EUR cooler sizing and engine performance results.

[00211 In order to mitigate the build-up of carbonaceous deposits in EGR cooler 40, EGR cooler 40 includes internal surfaces that define exhaust gas flow passages that include a coating of with potassium glass material 52, as shown in Fig. 3. Potassium glass material 52 provides for oxidation of the soot or carbonaceous material by oxygen. A coating of potassium glass material is effective in enhancing the rate of soot oxidation by oxygen and in lowering the temperature at which soot oxidation by oxygen occurs since the temperature required to oxidize soot deposits is normally higher than the temperature of the exhaust gas flowing through the EUR cooler 40. The graph in Fig. 4 illustrates that lower temperatures are required for soot conversion by oxygen in the presence of potassium glass material than are required in the absence of a potassium glass coating.

[00221 As used herein, the term potassium glass includes glass and glass type materials with potassium included in the glass composition. One example of a potassium glass is potassium calcium silicate (K2CaSiO4 or K-Ca-Silicate or "KCS"). Potassium glass such as KCS is capable of slowly releasing potassium K ions at the surface of the glass which interfaces with the carbonaceous deposits to enhance the soot oxidation rate by oxygen and minimize formation of a thick soot layer on the inner walls of EUR coo'er 40.

[0023] Tf any potassium W ions are lost overtime, they can he replaced by additional ion exchange interactions with the potassium glass. in this way, the use of potassium glass is advantageous over systems using K2C03 or KNO3 for soot oxidation promotion because these catalysts degrade after repeated thermal cycles due to the loss of potassium. in addition, potassium glass material has an insignificant effect on oxidation of nitrogen oxide (NO) and carbon monoxide (CO) in the exhaust gas passing through EGR cooler 40.

Potassium glass coating 52 functions to release potassium ions to the interface of the glass and the carbonaceous deposits, but does not function as an oxidation catalyst.

[0024] Fig. 3 shows the EGR cooler 40 in a schematic cross-sectional view, it being understood that any suitable EUR cooler with a potassium glass coating on the walls defining the exhaust flow passages therechrough are contemplated. The EGR cooler 40 includes a heat exchange vessel 51 with an inlet 42 for receiving exhaust gas from exhaust system 39 and an outlet 44 fluidly connected to the inlet 42 by one or more fluid passages 50. The heat exchange vessel 51 also contains a flow path 45 for a cooling medium that extends between a cooling medium inlet 46 fluidly connected to a cooling medium outlet 48. The cooling medium flow path 45 is configured around the one or more fluid passages to facilitate heat transfer between the cooling medium and the recirculated exhaust gas flowing through flow passages 50 within the EGR cooler 40.

[0025] OuUet 44 of heat exchange vessel Si is connected to intake system 33 to provide cooled recirculated exhaust gas thereto for mixing with the intake air flow to provide a charge flow to engine 12. The one or more fluid passages 50 defines a flow path for the recirculated exhaust gas to pass between inlet 42 and ouUet 44. Fhuid passages 50 are hounded by internal walls 54 of the heat exchange vessel SI. Tnternal walls 54 define one or more flow paths for the recirculated exhaust gas to pass through EGR cooler 40. Fluid passages 50 may be circular, rectangular, square, oval, or irregular in cross-sectional shape.

In addition, fluid passages 50 can he linear, wave-like, andlor change in cross-sectional dimension or direction along their length. Internal walls may be formed from a metal material or any material suitable for transmission of exhaust gas at the required temperatures and pressures therethrough.

[0026] The internal walls 54 of the fluid passages 50 include a potassium glass coating that contacts the recirculated portion of the exhaust gas stream flowing through the fluid passages 50 from the inlet 42 to the outlet 44. The internal walls 54 may be entirely coated or partially coated with potassium glass coating 52. For example, a potassium glass coating 52 may be applied to portions of the internal walls 54 that are adiacent the exhaust or hot side of the heat exchange vesse' 5! adjacent to inlet 42. In this arrangement, accumulation of carbonaceous deposits in the higher temperature regions of heat exchange vessel 51 are minimized where carbonaceous deposit formation potential is highest. In one embodiment, a potassium glass coating is applied on a length D that is less than 50% of an overall length of internal walls 54 between inlet 42 and ouUet 44. In another embodiment, the potassium glass coating is applied on a length D that is less than 25% of the overall length of internal walls 54. In still other embodiments, where the fluid passage 50 is completely circumscribed by an internal wall 54, the entirety of the internal wall 54 around the fluid passage 50 is coated with a potassium glass coating along all or a portion of the length of the fluid passage 50. In other embodiments, a selected portion or selected portions of the internal wall 54 around fluid passage 50 are coated along all or a portion of the length of the fluid passage 50.

[0027] Various aspects of the systems, apparatus, and methods are disclosed herein. As is evident from the figures and text presented above, a variety of embodiments according to the present invention are contemplated.

[0028] According to one aspect, an apparatus includes a heat exchange vessel comprising an inlet for receiving a stream of exhaust gas produced by an engine to he cooled by the heat exchange vessel, an outlet fluidly connected to the inlet for providing the cooled exhaust gas to an air intake of the engine, and at least one fluid passage between the inlet and the outlet that is defined by an internal surface. The internal surface is coated with a potassium glass material configured to contact the exhaust gas stream flowing through the at least one fluid passage.

[0029] In one embodiment, the potassium glass material is composed to release potassium in the presence of the exhaust gas stream to enhance an oxidation rate of soot deposits by oxygen on the internal surface of the heat exchange vessel. In another embodiment, the potassium glass material is composed so that conversion of CO to carbon dioxide CO2 in the exhaust gas passing through the fluid passage is insignificant, in yet another embodiment, the potassium glass material is composed so that conversion of NO to NO2 in the exhaust gas passing through the at least one fluid passage is insignificant.

[0039] Tn another embodiment, the potassium glass material is KCS. Tn yet another embodiment, the potassium glass material is applied only on a portion of the at least one fluid passage that is adjacent the inlet, where the portion is less than 50% of a length of the at least one fluid passage between the inlet and the outlet of the heat exchange vessel.

[0031] Tn another aspect, a method for reducing fouUng of an exhaust gas recirculation cooler is provided. The method includes operating an internal combustion engine system to produce an exhaust gas flow, the internal combustion engine system having an EGR system connecting an exhaust to an intake to provide exhaust gas flow to the intake, the EGR system including an EGR cooler between the exhaust and the intake; and contacting the exhaust gas flow through the EGR cooler with a potassium containing glass material applied as a coating on internal surfaces of the EGR cooler.

[00321 Tn one embodiment, the potassium containing glass material on the internal surfaces of the EGR cooler contains a potassium level sufficient to release potassium in the presence of the exhaust gas to increase an oxidization rate by oxygen of carbonaceous deposits on the internal surfaces of the EGR cooler. in another embodiment, the potassium containing glass material is composed so that conversion of CO to carbon dioxide CO2 in the exhaust gas flow passing through the EUR cooler is insignificant, in yet another embodiment, the potassium containing glass material is composed so that conversion of NO to NO2 in the exhaust gas flow passing through the EUR cooler is insignificant.

[00331 Tn a further embodiment, the potassium containing glass material is K2CaSiO4 (KCS). In another embodiment, the method includes increasing an oxidation rate by oxygen of carbonaceous deposits on the internal surfaces of the EGR cooler with the potassium released from the potassium glass coating without oxidation of CO and NO passing through tile EUR cooler. In yet another embodiment, the coating of potassium glass material is applied only on a portion of the internal surfaces adjacent an inlet to the EGR cooler.

[0034] According to another aspect, an engine system includes an internal combustion engine including a pluraUty of cylinders, an intake system configured to direct a charge flow to the plurality of cylinders and including a charge air cooler upstream of the plurality of cylinders, and an exhaust system configured to receive an exhaust gas from the plurality of cylinders. The system further includes an EGR system connecting the exhaust system with the intake system, the exhaust gas recircitlation system including an EGR cooler with an inlet and an outlet. The EGR cooler includes an internal surface defining at least one fluid passage between the inlet and the outlet, and the internal surface including a coating of potassium glass material that is configured to contact an exhaust gas flow passing through the at least one fluid passage.

[0035] Tn one embodiment, the engine system includes a turbocharger with a compressor upstream of the charge air cooler and a turbine in the exhaust system. In a refinement of this embodiment, the exhaust gas recirculation system inlet is fluidly connected to the exhaust system downstream of the turbine and to the intake system upstream of the compressor. In another refinement of this embodiment, the exhaust gas recirculation system inlet is fluidly connected to the exhaust system upstream of the turbine and to the intake system downstream of the compressor.

[0036] Tn another embodiment, the potassium glass material contains a potassium level sufficient to allow a release of potassium into the exhaust gas flow passing through the fluid passage of the EUR cooler that increases an oxidation rate by oxygen of soot deposits on the internal surface of the EGR cooler. In a further embodiment, the potassium glass material is composed so that conversion of CO to CO2 in the exhaust gas flow passing through the fluid passage of the exhaust gas cooler is insignificant. In still another embodiment, the potassium glass material is Composed SO that conversion of NO to NO2 in the exhaust gas flow passing through the fluid passage of the exhaust gas cooler is insignificant.

F00371 In another embodiment, the potassium glass material is KCS. In yet another embodiment, the potassium glass material is applied only on a portion of the at least one fluid passage that is adjacent the inlet, and the portion is less than 50% of a length of the at least one fluid passage between the inlet and the outlet of the EGR cooler.

[0038] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain exemplary embodiments have been shown and described and that all changes and modifications that come within the spirit of the inventions are desired to be protected.

F00391 It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow, in reading the claims, it is intended that when words such as "a," "an," "at least one," or "at least one portion" are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the daim. When the language "at east a portion' and/or "a portion" iS Lised the item can include a portion and/or the entire item unless specifically stated to the contrary.

Claims

WHAT IS CLAIMED IS: 1. All apparatus, comprising: a heat exchange vessel comprising an inlet for receiving a stream of exhaust gas produced by an engine to he cooled by the heat exchange vessel, an outlet fluidly connected to the inlet for providing the cooled exhaust gas to an air intake of the engine, at least one fluid passage between the inlet and the outlet that is defined by an internal surface, wherein the internal surface is coated with a potassium glass material configured to contact the exhaust gas stream flowing through the at least one fluid passage.
2. The apparatus of claim i, wherein the potassiLim glass material is composed to release potassium in the presence of the exhaust gas sneam to enhance an oxidation rate of soot deposits by oxygen on the internal surface of the heat exchange vessel.
3. The apparatus of claim 1, wherein the potassium glass material is composed so that conversion of carbon monoxide (CO) to carbon dioxide (C02) in the exhaust gas passing through the fluid passage is insignificant.
4. The apparatus of claim 1, wherein the potassium glass material is composed so that conversion of nitric oxide (NO) to nitrogen dioxide (NO2) in the exhaust gas passing through the at least one fluid passage is insignificant.
5. The apparatus of claim 1, wherein the potassium glass material is K2CaSiO4 (KCS).
6. The apparatus of claim i, wherein the potassiLim glass material is applied only on a portion of the at least one fluid passage that is adjacent the inlet, wherein the portion is less than 50% of a length of the at least one fluid passage between the inlet and the outlet of the heat exchange vessel.
7. A method for reducing fouling of an exhaust gas recirculation cooler, comprising: operating an internal combustion engine system to produce an exhaust gas flow, the internal combustion engine system having an exhaust gas recirculation (EGR) system connecting an exhaust to an intake to provide exhaust gas flow to the intake, the EGR system including an EGR cooler between the exhaList and the intake; and contacting the exhaust gas flow through the EGR cooler with a potassium containing glass material applied as a coating on internal surfaces of the EGR cooler.
8. The method of claim 7, wherein the potassium containing glass material on the internal surfaces of the EGR cooler contains a potassium level sufficient to release potassium in the presence of the exhaust gas to increase an oxidization rate by oxygen of carbonaceous deposits on the internal surfaces of the EGIR cooler.
9. The method of claim 7, wherein the potassium containing glass material is composed so that conversion of carbon monoxide (CO) to carbon dioxide (C02) in the exhaust gas flow passing through the EUR cooler is insignificant.
10. The method of daim 7, wherein the potassium containing &ass material is composed so that conversion of nitric oxide (NO) to nitrogen dioxide (NO2) in the exhaust gas flow passing through the EGR cooler is insignificant.
I. The method of daim 7, wherein the potassium containing g'ass material is KnCaSiO4 (KCS).
12. The method of daim 7, further comprising increasing an oxidation rate by oxygen of carbonaceous deposits on the illternal surfaces of the EGR cooler with the potassium r&eased from the potassium glass coating withoLit oxidation of CO and NO passing through the EGR cooler.
13. The method of claim 7, wherein the coating of potassium glass material is applied only on a portion of the internal surfaces adjacent an inlet to the EGR cooler.
14. An engine system, comprising: an internal combustion engine induding a plurality of cylinders; an intake system configured to direct a charge flow to the plurality of cylinders and including a charge air cooler upstream of the plurality of cylinders; an exhaust system configured to receive an exhaust gas from the plurality of cylinders; and an exhaust gas recirculation (EGR) system collecting the exhaust system with the intake system, the exhaust gas recirculation system including an EUR cooler with an inlet and an outlet, the EGR cooler including an internal surface defining at least one fiLlid passage between the inlet and the outlet, the internal surface including a coating of potassium glass material that is configured to contact an exhaust gas flow passing through the at least one fluid passage.
15. The system of claim 14, wherein the engine system includes a turbocharger with a compressor upstream of the charge air cooler, the turbocharger further including a turbine in the exhaList system.lb. The system of claim IS, wherein the exhaList gas recirculatiori system inlet is fluidly connected to the exhaust system downstream of the turbine and to the intake system upstream of the compressor.17. The system of claim 15, wherein the exhaust gas recirculation system inlet is fluidly connected to the exhaust system upstream of the turbine and to the intake system downstream of the compressor.18. The system of claim 14, wherein the potassium glass material contains a potassium level sufficient to allow a release of potassium into the exhaust gas flow passing through the fluid passage of the EGR cooler to increase an oxidation rate by oxygen of soot deposits on the intemal surface of the EUR cooler.19. The system of claim 14, wherein tile potassium g'ass material is composed so that conversion of carbon monoxide (CO) to carbon dioxide (C02) in the exhaust gas flow passing through the fluid passage of the exhaust gas cooler is insignificant.20. The system of claim 14, wherein the potassium &ass material is composed so that conversion of nitric oxide (NO) to rntrogen dioxide (NO2) in the exhaust gas flow passing through the fluid passage of the exhaust gas cooler is insignificant.21. The system of claim 14, wherein the potassium glass material is K2CaSiO4 (KCS).22. The system of claim 14, wherein the potassium glass material is applied only on a portion of the at least one fluid passage that is adjacent the inlet, wherein the portion is less than 50% of a length of the at least one fluid passage between the inlet and the outlet of the EGR cooler.