# Patent

## Title
System, method, and apparatus for determining aftertreatment fluid quality

## Abstract

A method includes determining a first NOx conversion efficiency (η) value and determining that a diesel exhaust fluid (DEF) level has increased a threshold amount. Further, the method includes determining a second NOx conversion η value and comparing the first NOx conversion η value and the second NOx conversion η value, determining a NOx conversion η change in response to comparing, and determining a DEF quality indicator in response to the NOx conversion η change.

## Background
CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/247,270 filed on Sep. 30, 2009, which is incorporated by reference herein in the entirety.


BACKGROUND
The technical field generally relates to monitoring fluid quality for aftertreatment systems, and more particularly but not exclusively relates to aftertreatment systems for internal combustion engines burning diesel fuel. Presently available internal combustion engines require aftertreatment systems in many cases to meet stringent emissions requirements. Some aftertreatment systems require specific fluids for operation. These fluids may require manual filling and due to their expense may be subject to bypass or manipulation, and/or subject to varying quality. One example of such a fluid is a mixture of water and urea called “diesel exhaust fluid”, which is utilized in selective catalytic reduction (SCR) aftertreatment systems. When the fluid is not present or has degraded quality, the system may need to adjust to meet emissions requirements, and further the fluid quality may need to be reported for maintenance or regulatory requirements. Direct measurements and verification of fluid quality are unavailable for most fluids. Therefore, further technological developments are desirable in this area.
SUMMARY
One embodiment of the present application includes a unique apparatus for determining aftertreatment fluid quality. Other embodiments include unique aftertreatment fluid quality determining apparatuses, systems, and methods. Further embodiments, inventions, forms, objects, features, advantages, aspects, and benefits of the present application are otherwise set forth or become apparent from the description and drawings included herein.



BRIEF DESCRIPTION OF THE DRAWINGS
The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
FIG. 1 is a schematic diagram of a system for determining an aftertreatment fluid quality.
FIG. 2 is a schematic diagram of an apparatus for determining an aftertreatment fluid quality.



DETAILED DESCRIPTION
For purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, any alterations and further modifications in the illustrated device, and any further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
FIG. 1 is a schematic diagram of a system 100 for determining an aftertreatment fluid quality. The system 100 includes an internal combustion engine 102 producing an exhaust stream 116, where the exhaust stream 116 includes an amount of NOx. The system 100 includes a NOx conversion catalyst 104 that reduces at least a portion of the amount of NOx, a reagent source 108 that stores an amount of a NOx reductant reagent 112, and a reagent injector 106 that receives the NOx reductant reagent 112 from the reagent source 108 and provides the NOx reductant reagent 112 to the exhaust stream 116 at a position upstream of the NOx conversion catalyst 104. The system 100 further includes at least one NOx sensor 110 operably coupled to the exhaust stream 116 at a position downstream of the NOx conversion catalyst 104.
The system 100 further includes a controller 114 that performs certain operations for determining an aftertreatment fluid quality, where the NOx reductant reagent 112 is the aftertreatment fluid. The NOx reductant reagent 112 may be ammonia, urea, urea with water, a diesel exhaust fluid, hydrogen, fuel, reformed fuel, or any other reducing agent understood in the art. In one embodiment, the NOx reductant reagent 112 is a urea-water mixture that is supposed to be a mixture having a specified urea concentration. The controller 114 includes modules structured to functionally execute operations to determine aftertreatment fluid quality. In certain embodiments, the controller 114 includes a NOx conversion efficiency (η) module 202, a NOx reductant reagent status module 204, and a NOx reductant reagent quality module 206. More specific descriptions of the operations of the controller 114 for exemplary embodiments are included in the section referencing FIG. 2. In certain embodiments, the controller 114 forms a portion of a processing subsystem including one or more computing devices, the devices having memory, processing, and communication hardware. The controller 114 may be a single device or a number of distributed devices, and the functions of the controller 114 may be performed by hardware or software.
FIG. 2 is a schematic diagram of an apparatus 200 for determining an aftertreatment fluid quality. The apparatus 200 includes a controller 114 having a NOx conversion module 202, a NOx reductant reagent status module 204, and a NOx reductant reagent quality module 206 structured to functionally execute the operations of the controller 114. The description herein, including modules, emphasizes the structural independence of the aspects of the controller 114, and illustrates one grouping of operations and responsibilities of the controller 114. Other groupings that execute similar overall operations are understood within the scope of the present application. Modules may be implemented in hardware and/or software on computer readable medium, and modules may be distributed across various hardware or software components.
The NOx conversion efficiency (η) module 202 determines a NOx conversion η value 208 for the NOx conversion catalyst 104. The NOx conversion η value 208 may be determined by any method understood in the art. Non-limiting examples include measuring or modeling a NOx amount in the exhaust stream 116 upstream of the NOx conversion catalyst 104 and measuring the NOx amount in the exhaust stream 116 downstream of the NOx conversion catalyst 104, for example with a NOx sensor 110. The NOx conversion η module 202 may receive the NOx conversion η value 208 as a datalink or network communication, and/or may read the NOx conversion η value 208 as a parameter stored on a computer readable medium.
The NOx reductant reagent status module 204 determines a NOx reductant reagent level 210 and/or a NOx reductant reagent fill indicator 212, and provides a NOx reductant reagent level increase event indication 214. The NOx reductant reagent status module 204 may determine the NOx reductant reagent level 210 and/or a NOx reductant reagent fill indicator 212 from a sensor level, from a fill indication value provided as a datalink or network communication, from reading a parameter stored on a computer readable medium, and/or from determining that a maintenance event of filling the reagent source 108 has occurred. For example, a maintenance parameter may be set by a computerized tool or a “pedal dance” after a filling of the reagent source 108 occurs. In other examples, a NOx reductant reagent level 210 may be tracked over time, and an increase amount greater than a nominal amount may be interpreted by the NOx reductant reagent status module 204 as a NOx reductant reagent level increase event indication 214.
The NOx reductant reagent quality module 206 compares a first NOx conversion η value 216, stored before the NOx reductant reagent level increase event 214, to a second NOx conversion η value 218, determined after the NOx reductant reagent level increase event 214, and determines a NOx conversion η change 220 in response to the first NOx conversion η value 216 and the second NOx conversion η value 218. The comparison of the first NOx conversion η value 216 and the second NOx conversion η value 218 may be an absolute comparison (e.g. 95%−90%=5% Δη), or a relative comparison (e.g. (90%/95%)=94.7% of prior η). The NOx reductant reagent quality module 206 determines a NOx reductant reagent quality indicator 222 in response to the NOx conversion η change 220.
In certain embodiments, the NOx reductant reagent quality module 206 determines the NOx reductant reagent quality indicator 222 regardless of the value of the first NOx conversion η value 216, for example even where the first NOx conversion η value 216 is a value below a design NOx conversion η value 226, or where the first NOx conversion η value 216 is below an emissions compliant NOx conversion η 228. In certain embodiments, the NOx conversion η module 202 determines whether the second NOx conversion η value 218 is at least equal to the emissions compliant NOx conversion η value 228, and the NOx reductant reagent quality module 206 further determines the NOx reductant reagent quality indicator 222 is “compliant degraded” in response to the NOx conversion η module 202 determining the second NOx conversion η value 218 is at least equal to the emissions compliant NOx conversion η value 228 and determining the NOx conversion η change 220 is greater than a NOx conversion η change threshold 224. The NOx conversion η change threshold 224 for comparing the NOx conversion η change 220 is based upon the accepted variability in the NOx reductant reagent 112 and/or the variability in the NOx reductant reagent 112 that is desired to be detected. For example, if the NOx reductant reagent 112 is a fluid that is 32.5% urea by weight, and a solution of 25% urea by weight is the accepted level of variability, the change for comparing the NOx conversion η change 220 is the amount of change in the NOx conversion η value 208 that is normally expected to occur from a 25% urea solution being utilized instead of a 32.5% urea solution. In another example, if the NOx reductant reagent 112 is a fluid that is 32.5% urea by weight, and it is desired to detect anything down to a 5% urea solution, the change for comparing the NOx conversion η change 220 is the amount of change in the NOx conversion η value 208 that is normally expected to occur from a 5% urea solution being utilized instead of a 32.5% urea solution. The NOx reductant reagent quality module 206 may utilize multiple comparison NOx conversion η change thresholds 224 for the NOx conversion η change 220 to distinguish between NOx reductant reagent 112 that are degraded versus failed or non-compliant.
In certain embodiments, the NOx reductant reagent quality module 206 further determines the NOx reductant reagent quality indicator 222 as “non-compliant degraded” in response to the NOx conversion η module 202 determining the second NOx conversion η value 218 is not at least equal to the emissions compliant NOx conversion η value 228 and further to determining the NOx conversion η change 220 is greater than a NOx conversion η change threshold 224. For example, if the NOx reduction catalyst 104 is not able to convert a compliant fraction of the NOx in the exhaust stream 116 (i.e. the NOx conversion η value 208 is lower than the emissions compliant NOx conversion η value 228), but there is not enough observed difference between the first NOx conversion η value 216 and the second NOx conversion η value 218, then the lack of compliance, in certain embodiments, is not attributed to the quality of the NOx reductant reagent 112.
In certain embodiments, the NOx conversion η module 202 further determines whether the first NOx conversion η value 216 is at least equal to the emissions compliant NOx conversion η value 228. The NOx reductant reagent quality module 206 further determines the NOx reductant reagent quality indicator 222 is “degraded causing non-compliance” in response to the NOx conversion η module 202 determining the second NOx conversion η value 218 is not at least equal to the emissions compliant NOx conversion η value 228, determining that the first NOx conversion η value 216 is at least equal to the emissions compliant NOx conversion η value 228, and determining the NOx conversion η change 220 is greater than a NOx conversion η change threshold 224. The NOx reductant reagent quality module 206 further determines the NOx reductant reagent quality indicator 222 is “compliant degraded” in response to the NOx conversion η module 202 determining the second NOx conversion η value 218 is at least equal to the emissions compliant NOx conversion η value 228, determining that the first NOx conversion η value 216 is at least equal to the emissions compliant NOx conversion η value 228, and determining the NOx conversion η change 220 is greater than a NOx conversion η change threshold 224.
The NOx reductant reagent quality module 206 further determines that the NOx reductant reagent quality indicator 222 is “enriched” in response to the NOx conversion η module 202 determining the second NOx conversion η value 218 is at least equal to the emissions compliant NOx conversion η value 228, determining that the first NOx conversion η value 216 is not at least equal to the emissions compliant NOx conversion η value 228, and determining the NOx conversion η change 220 is greater than a NOx conversion η change threshold 224. The NOx reductant reagent quality module 206 further determines the NOx reductant reagent quality indicator 222 is “enriched” in response to the NOx conversion η change 220 having a positive magnitude, and determines the NOx reductant reagent quality indicator 222 is “diluted” in response to the NOx conversion η change 220 having a negative magnitude.
The names described for the NOx reductant reagent quality indicator 222 are exemplary and non-limiting. Equivalent names, names conveying similar information, and numbers stored on computer readable medium that have a translatable meaning to similar information are contemplated herein. The sign conventions utilized, such as the NOx reductant reagent quality indicator 222 being “diluted” where the NOx conversion η change 220 has a negative magnitude, are of course reversible.
Table 1 illustrates certain non-limiting behaviors of the NOx reductant reagent quality module 206 in response to various parameters in the system 100. Within Table 1, the numbers refer to elements from FIG. 2, for example 220 represents the NOx conversion η change 220, and the indicator “- - -” illustrates that the parameter or value is not considered for the example situation.







TABLE 1







Exemplary behaviors of the NOx reductant reagent quality module 206.











216 > 228
218 > 228
220 > 224
Sign of 220
Value of 222





YES
YES
YES
NEG
Compliant degraded






(diluted)


YES
NO
YES
NEG
Degraded (diluted)






causing






non-compliance


NO
NO
YES
NEG
Non-compliant






degraded (diluted)


NO
YES
YES
POS
Enriched


—
—
YES
POS
Enriched


—
—
YES
NEG
Diluted


—
—
NO
—
Store current 208 as






next 216, exit









In the example provided in Table 1, where the magnitude of the NOx conversion η change 220 indicates that the fluid quality has not changed in response to the NOx reductant reagent level increase event 214, the NOx reductant reagent quality module 206 may store the present NOx conversion η value 208 as the first NOx conversion η value 216 and the controller 114 may allow the fluid quality algorithm to exit. The first NOx conversion η value 216 may be updated between NOx reductant reagent level increase events 214, for example with a filtered value of the observed NOx conversion H values 208, or the first NOx conversion η value 216 may be held constant until another NOx reductant reagent level increase event 214 is detected.
An exemplary procedure for determining an exhaust treatment fluid quality is described. The exemplary procedure includes an operation to determining a first parameter value corresponding to a first NOx conversion efficiency (η) value. The procedure further includes an operation to determine that an exhaust treatment fluid level has increased a threshold amount, and an operation to determine a second parameter value corresponding to a second NOx conversion η value. The procedure includes an operation to compare the first parameter value and the second parameter value, to determine a NOx conversion η change in response to comparing, and to determine an exhaust treatment fluid quality indicator in response to the NOx conversion η change.
The exemplary procedure includes an operation to determine the exhaust treatment fluid quality indicator as enriched in response to the NOx conversion η change having a positive magnitude, and to determine the exhaust treatment fluid quality indicator as diluted in response to the NOx conversion η change having a negative magnitude. In certain embodiments, the exhaust treatment fluid is a NOx reductant reagent. The NOx reductant reagent can include ammonia, urea, urea with water, a diesel exhaust fluid, hydrogen, fuel, and/or reformed fuel.
As is evident from the figures and text presented above, a variety of embodiments according to the present invention are contemplated.
One exemplary embodiment is a method including determining a first NOx conversion efficiency value, determining that a diesel exhaust fluid (DEF) level has increased a threshold amount, and determining a second NOx conversion efficiency value. The method further includes comparing the first NOx conversion efficiency value and the second NOx conversion efficiency value, determining a NOx conversion efficiency change in response to the comparing, and determining a DEF quality indicator in response to the NOx conversion efficiency change.
Certain embodiments of the method include one or more of the following described operations. Operations may be re-ordered, combined, split, omitted, or substituted. The method includes determining that the DEF level has increased the threshold amount by determining that a DEF tank has been filled. The first NOx conversion efficiency value may be a value that is below a design NOx conversion efficiency value.
In further embodiments, the method includes determining whether the second NOx conversion efficiency value is at least equal to an emissions compliant NOx conversion efficiency value. In response to determining the second NOx conversion efficiency value is at least equal to the emissions compliant NOx conversion efficiency value and determining the NOx conversion efficiency change is greater than a NOx conversion η change threshold, the method includes determining the DEF quality indicator is compliant degraded. In response to determining the second NOx conversion efficiency value is not at least equal to the emissions compliant NOx conversion efficiency value and determining the NOx conversion efficiency change is greater than a NOx conversion η change threshold, the method includes determining the DEF quality indicator is non-compliant degraded. The method further includes determining whether the first NOx conversion efficiency value is at least equal to the emissions compliant NOx conversion efficiency value.
In response to determining the second NOx conversion efficiency value is not at least equal to the emissions compliant NOx conversion efficiency value, determining that the first NOx conversion efficiency value is at least equal to the emissions compliant NOx conversion efficiency value, and determining the NOx conversion efficiency change is greater than a NOx conversion η change threshold, the method includes determining the DEF quality indicator is degraded causing non-compliance. In response to determining the second NOx conversion efficiency value is at least equal to the emissions compliant NOx conversion efficiency value, determining that the first NOx conversion efficiency value is at least equal to the emissions compliant NOx conversion efficiency value, and determining the NOx conversion efficiency change is greater than a NOx conversion η change threshold, the method includes determining the DEF quality indicator is compliant degraded. In response to determining the second NOx conversion efficiency value is at least equal to the emissions compliant NOx conversion efficiency value, determining that the first NOx conversion efficiency value is not at least equal to the emissions compliant NOx conversion efficiency value, and determining the NOx conversion efficiency change is greater than a NOx conversion η change threshold, the method includes determining the DEF quality indicator is enriched.
In certain embodiments, the method further includes determining the DEF quality indicator is enriched in response to the NOx conversion efficiency change having a positive magnitude, and determining the DEF quality indicator is diluted in response to the NOx conversion efficiency change having a negative magnitude.
Another exemplary embodiment is a system including an internal combustion engine producing an exhaust stream, wherein the exhaust stream includes an amount of NOx, a NOx conversion catalyst that reduces at least a portion of the amount of NOx, a reagent source that stores an amount of a NOx reductant reagent and a reagent injector that receives the NOx reductant reagent from the reagent source and provides the NOx reductant reagent to the exhaust stream at a position upstream of the NOx conversion catalyst. The system further includes at least one NOx sensor operably coupled to the exhaust stream at a position downstream of the NOx conversion catalyst, and a controller structured to perform certain operations for determining an aftertreatment fluid quality. The controller includes modules structured to functionally execute the operations, and in certain embodiments includes a NOx conversion efficiency module, a NOx reductant reagent status module, and a NOx reductant reagent quality module. The NOx conversion efficiency module determines a NOx conversion efficiency value for the NOx conversion catalyst. The NOx reductant reagent status module determines a NOx reductant reagent level and/or a NOx reductant reagent fill indicator, and provides a NOx reductant reagent level increase event indication. The NOx reductant reagent quality module compares a first NOx conversion efficiency value stored before the NOx reductant reagent level increase event to a second NOx conversion efficiency value determined after the NOx reductant reagent level increase event, determines a NOx conversion efficiency change in response to the first NOx conversion efficiency value and the second NOx conversion efficiency value, and determines a NOx reductant reagent quality indicator in response to the NOx conversion efficiency change. In certain embodiments, the NOx reductant reagent comprises a DEF.
Certain embodiments of the system include one or more of the following described features. Features may be combined, split, omitted, or substituted. The system includes the first NOx conversion efficiency value as a value that is below a design NOx conversion efficiency value. The NOx conversion efficiency module may further determine whether the second NOx conversion efficiency value is at least equal to an emissions compliant NOx conversion efficiency value. The NOx reductant reagent quality module further determines the NOx reductant reagent quality indicator is compliant degraded in response to the NOx conversion efficiency module determining the second NOx conversion efficiency value is at least equal to the emissions compliant NOx conversion efficiency value and determining the NOx conversion efficiency change is greater than a NOx conversion η change threshold.
The NOx reductant reagent quality module further determines the NOx reductant reagent quality indicator is non-compliant degraded in response to the NOx conversion efficiency module determining the second NOx conversion efficiency value is not at least equal to the emissions compliant NOx conversion efficiency value and determining the NOx conversion efficiency change is greater than a NOx conversion η change threshold. The NOx conversion efficiency module further determines whether the first NOx conversion efficiency value is at least equal to the emissions compliant NOx conversion efficiency value. The NOx reductant reagent quality module further determines the NOx reductant reagent quality indicator is degraded causing non-compliance in response to the NOx conversion efficiency module determining the second NOx conversion efficiency value is not at least equal to the emissions compliant NOx conversion efficiency value, determining that the first NOx conversion efficiency value is at least equal to the emissions compliant NOx conversion efficiency value, and determining the NOx conversion efficiency change is greater than a NOx conversion η change threshold.
The NOx reductant reagent quality module further determine the NOx reductant reagent quality indicator is compliant degraded in response to the NOx conversion efficiency module determining the second NOx conversion efficiency value is at least equal to the emissions compliant NOx conversion efficiency value, determining that the first NOx conversion efficiency value is at least equal to the emissions compliant NOx conversion efficiency value, and determining the NOx conversion efficiency change is greater than a NOx conversion η change threshold. The NOx reductant reagent quality module further determine the NOx reductant reagent quality indicator is enriched in response to the NOx conversion efficiency module determining the second NOx conversion efficiency value is at least equal to the emissions compliant NOx conversion efficiency value, determining that the first NOx conversion efficiency value is not at least equal to the emissions compliant NOx conversion efficiency value, and determining the NOx conversion efficiency change is greater than a NOx conversion η change threshold. The NOx reductant reagent quality module further determines the NOx reductant reagent quality indicator is enriched in response to the NOx conversion efficiency change having a positive magnitude, and determines the NOx reductant reagent quality indicator is diluted in response to the NOx conversion efficiency change having a negative magnitude.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment(s), but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as permitted under the law. Furthermore it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that feature so described may be more desirable, it nonetheless may not be necessary and any embodiment lacking the same may be contemplated as within the scope of the invention, that 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” and “at least a portion” are used, there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Further, when the language “at least a portion” and/or “a portion” is used the item may include a portion and/or the entire item unless specifically stated to the contrary.

## Claims

1. A method, comprising:
determining a first NOx conversion efficiency (η) value;
increasing a diesel exhaust fluid (DEF) level of a DEF in a DEF storage source a threshold amount;
determining a second NOx conversion η value when the DEF level has increased the threshold amount;
determining whether the second NOx conversion η value is at least equal to an emissions compliant NOx conversion η value; and
comparing the first NOx conversion η value and the second NOx conversion η value, determining a NOx conversion η change in response to comparing, and determining a DEF quality indicator associated with a NOx reduction capability of the DEF in the DEF storage source in response to the NOx conversion η change, wherein in response to determining the second NOx conversion value is at least equal to the emissions compliant NOx conversion η value and determining the NOx conversion η change is greater than a NOx conversion η change threshold, determining the DEF quality indicator is compliant degraded.

2. The method of claim 1, wherein determining that the DEF level has increased the threshold amount comprises determining that the DEF storage source has been filled.

3. The method of claim 1, wherein the first NOx conversion η value is a value that is below a design NOx conversion η value.

4. The method of claim 1, further comprising:
in response to determining the second NOx conversion η value is not at least equal to the emissions compliant NOx conversion η value and determining the NOx conversion η change is greater than the NOx conversion η change threshold;
determining the DEF quality indicator is non-compliant degraded.

5. The method of claim 1, further comprising determining whether the first NOx conversion η value is at least equal to the emissions compliant NOx conversion η value.

6. The method of claim 5, further comprising:
in response to determining the second NOx conversion η value is not at least equal to the emissions compliant NOx conversion η value, determining that the first NOx conversion η value is at least equal to the emissions compliant NOx conversion η value, and determining the NOx conversion η change is greater than the NOx conversion η change threshold;
determining the DEF quality indicator is degraded causing non-compliance.

7. The method of claim 5, further comprising:
in response to determining the second NOx conversion η value is at least equal to the emissions compliant NOx conversion η value, determining that the first NOx conversion η value is at least equal to the emissions compliant NOx conversion η value, and determining the NOx conversion η change is greater than the NOx conversion η change threshold;
determining the DEF quality indicator is compliant degraded.

8. The method of claim 5, further comprising:
in response to determining the second NOx conversion η value is at least equal to the emissions compliant NOx conversion η value, determining that the first NOx conversion η value is not at least equal to the emissions compliant NOx conversion η value, and determining the NOx conversion η change is greater than the NOx conversion η change threshold;
determining the DEF quality indicator is enriched.

9. The method of claim 5, further determining the DEF quality indicator as enriched in response to the NOx conversion η change having a positive magnitude and determining the DEF quality indicator as diluted in response to the NOx conversion η change having a negative magnitude.

10. A system, comprising:
an internal combustion engine producing an exhaust stream, the exhaust stream including an amount of NOx;
a NOx conversion catalyst that reduces at least a portion of the amount of NOx;
a reagent source that stores an amount of a NOx reductant reagent and a reagent injector that receives the NOx reductant reagent from the reagent source and provides the NOx reductant reagent to the exhaust stream at a position upstream of the NOx conversion catalyst;
at least one NOx sensor operably coupled to the exhaust stream at a position downstream of the NOx conversion catalyst; and
a controller, comprising:
a NOx conversion efficiency (η) module structured to determine a NOx conversion η value for the NOx conversion catalyst;
a NOx reductant reagent status module structured to determine one of a NOx reductant reagent level and a NOx reductant reagent fill indicator of the NOx reductant reagent in the reagent source, and to provide a NOx reductant reagent level increase event indication of the NOx reductant reagent in the reagent source;

a NOx reductant reagent quality module structured to compare a first NOx conversion η value stored before the NOx reductant reagent level increase event to a second NOx conversion η value determined after the NOx reductant reagent level increase event, to determine a NOx conversion η change in response to the first NOx conversion η value and the second NOx conversion η value, and to determine a NOx reductant reagent quality indicator associated with a NOx reduction capability of the NOx reductant reagent in the reagent source in response to the NOx conversion η change; and
wherein the NOx reductant reagent quality module is further structured to determine the NOx reductant reagent quality indicator as enriched in response to the NOx conversion η change having a positive magnitude and to determine the NOx reductant reagent quality indicator as diluted in response to the NOx conversion efficiency change having a negative magnitude.

11. The system of claim 10, wherein the NOx reductant reagent comprises a diesel exhaust fluid (DEF).

12. The system of claim 10, wherein the first NOx conversion η value is a value that is below a design NOx conversion η value.

13. The system of claim 10, wherein the NOx conversion η module is further structured to determine whether the second NOx conversion η value is at least equal to an emissions compliant NOx conversion η value.

14. The system of claim 13, wherein the NOx reductant reagent quality module is further structured to:
in response to the NOx conversion η module determining the second NOx conversion η value is at least equal to the emissions compliant NOx conversion η value and determining the NOx conversion η change is greater than a NOx conversion η change threshold;
determine the NOx reductant reagent quality indicator is compliant degraded.

15. The system of claim 13, wherein the NOx reductant reagent quality module is further structured to:
in response to the NOx conversion η module determining the second NOx conversion η value is not at least equal to the emissions compliant NOx conversion η value and determining the NOx conversion η change is greater than a NOx conversion η change threshold;
determine the NOx reductant reagent quality indicator is non-compliant degraded.

16. The system of claim 13, wherein the NOx conversion η module is further structured to determine whether the first NOx conversion η value is at least equal to the emissions compliant NOx conversion η value.

17. The system of claim 16, wherein the NOx reductant reagent quality module is further structured to:
in response to the NOx conversion η module determining the second NOx conversion η value is not at least equal to the emissions compliant NOx conversion η value, determining that the first NOx conversion η value is at least equal to the emissions compliant NOx conversion η value, and determining the NOx conversion η change is greater than a NOx conversion η change threshold;
determine the NOx reductant reagent quality indicator is degraded causing non-compliance.

18. The system of claim 16, wherein the NOx reductant reagent quality module is further structured to:
in response to the NOx conversion η module determining the second NOx conversion η value is at least equal to the emissions compliant NOx conversion η value, determining that the first NOx conversion η value is at least equal to the emissions compliant NOx conversion η value, and determining the NOx conversion η change is greater than a NOx conversion η change threshold;
determine the NOx reductant reagent quality indicator is compliant degraded.

19. A method, comprising:
determining a first parameter value corresponding to a first NOx conversion efficiency (η) value;
increasing an exhaust treatment fluid level in an exhaust treatment fluid storage source a threshold amount;
determining a second parameter value corresponding to a second NOx conversion η value when the exhaust treatment fluid level has increased the threshold amount; and
comparing the first parameter value and the second parameter value, determining a NOx conversion η change in response to comparing, and determining an exhaust treatment fluid quality indicator associated with a NOx reduction capability of the exhaust treatment fluid in the exhaust treatment fluid storage source in response to the NOx conversion η change, and further determining the exhaust treatment fluid quality indicator as enriched in response to the NOx conversion η change having a positive magnitude and determining the exhaust treatment fluid quality indicator as diluted in response to the NOx conversion η change having a magnitude.

20. The method of claim 19, wherein the exhaust treatment fluid comprises a NOx reductant reagent.

21. The method of claim 20, wherein the NOx reductant reagent comprises a reductant selected from the reductants consisting of: ammonia, urea, urea with water, a diesel exhaust fluid, hydrogen, fuel, and reformed fuel.

22. An apparatus, comprising:
a NOx conversion efficiency (η) module structured to determine a NOx conversion η value for a NOx conversion catalyst;
a NOx reductant reagent status module structured to determine one of a NOx reductant reagent level and a NOx reductant reagent fill indicator of a NOx reductant reagent in a storage source, and to provide a NOx reductant reagent level increase event indication of the NOx reductant reagent in the storage source; and
a NOx reductant reagent quality module structured to compare a first NOx conversion η value stored before the NOx reductant reagent level increase event to a second NOx conversion η value determined after the NOx reductant reagent level increase event, to determine a NOx conversion η change in response to the first NOx conversion η value and the second NOx conversion η value, and to determine a NOx reductant reagent quality indicator associated with a NOx reduction capability of the NOx reductant reagent in the storage source in response to the NOx conversion η change, wherein the NOx conversion η module is further structured to determine whether the second NOx conversion η value is at least equal to an emissions compliant NOx conversion η value, and in response to the NOx conversion η module determining the second NOx conversion η value is at least equal to the emissions compliant NOx conversion η value and determining the NOx conversion η change is greater than a NOx conversion η change threshold, determine the NOx reductant reagent quality indicator is compliant degraded.

23. The apparatus of claim 22, wherein the first NOx conversion η value is a value that is below a design NOx conversion η value.

24. The apparatus of claim 22, wherein the NOx reductant reagent quality module is further structured to:
in response to the NOx conversion η module determining the second NOx conversion η value is not at least equal to the emissions compliant NOx conversion η value and determining the NOx conversion η change is greater than the NOx conversion η change threshold;
determine the NOx reductant reagent quality indicator is non-compliant degraded.

25. The apparatus of claim 22, wherein the NOx conversion η module is further structured to determine whether the first NOx conversion η value is at least equal to the emissions compliant NOx conversion η value, and wherein the NOx reductant reagent quality module is further structured to:
in response to the NOx conversion η module determining the second NOx conversion η value is not at least equal to the emissions compliant NOx conversion η value, determining that the first NOx conversion η value is at least equal to the emissions compliant NOx conversion η value, and determining the NOx conversion η change is greater than the NOx conversion η change threshold;
determine the NOx reductant reagent quality indicator is degraded causing non-compliance.

26. The apparatus of claim 22, wherein the NOx conversion η module is further structured to determine whether the first NOx conversion η value is at least equal to the emissions compliant NOx conversion η value, and wherein the NOx reductant reagent quality module is further structured to:
in response to the NOx conversion η module determining the second NOx conversion η value is at least equal to the emissions compliant NOx conversion η value, determining that the first NOx conversion η value is at least equal to the emissions compliant NOx conversion η value, and determining the NOx conversion η change is greater than the NOx conversion η change threshold;
determine the NOx reductant reagent quality indicator is compliant degraded.

27. The apparatus of claim 22, wherein the NOx conversion η module is further structured to determine whether the first NOx conversion η value is at least equal to the emissions compliant NOx conversion η value, and wherein the NOx reductant reagent quality module is further structured to:
in response to the NOx conversion efficiency module determining the second NOx conversion efficiency value is at least equal to the emissions compliant NOx conversion efficiency value, determining that the first NOx conversion η value is not at least equal to the emissions compliant NOx conversion efficiency value, and determining the NOx conversion efficiency change is greater than the NOx conversion η change threshold;
determine the NOx reductant reagent quality indicator is enriched.