[0001] The present disclosure, in general, relates to exhaust emissions control systems for internal combustion engines. In particular, the present disclosure relates to method and system for detecting the condition of the diesel particulate filter (DPF) that is installed for the removal of soot from the exhaust gas in a diesel engine exhaust system; and most particularly, to a method and system for safeguarding the DPF and other components of the EGR system (Exhaust Gas Recirculation system).
BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Internal combustion engine exhaust emissions, and especially diesel engine exhaust emissions, have recently come under scrutiny with the advent of stricter regulations, both in India and abroad. While diesel engines are known to be more economical to run than spark-ignited engines, diesel engines inherently suffer disadvantages in the area of emissions because fuel is injected during the compression stroke as opposed to during the intake stroke in a spark-ignited engine. As a result, a diesel engine has less time for the thorough mixing of the air and fuel before ignition occurs. For this and other reasons, diesel engine exhaust typically contains incompletely burned fuel known as particulate matter, or “soot”.
[0004] It is known to use a diesel particulate filter (DPF) to trap soot particulates in diesel exhaust gas. During such use, a DPF progressively loads up with accumulated soot and therefore must be regenerated at operating intervals by burning off the trapped particulates, typically on a fixed schedule and by oxygen and fuel enrichment of the exhaust stream entering the DPF.
[0005] In a typical prior art single-phase regeneration scheme, the inlet temperature to the DPF is targeted to a certain predetermined value, for example, 600° C. The initial process may involve ramping of the DPF temperature at various rates to prevent excessive combustion of wet soot (soot impregnated with unburned hydrocarbons) which is highly flammable and can cause uncontrolled combustion that can damage a DPF. Once the target temperature at the DPF inlet is reached, that target temperature is maintained until the end of the allowed regeneration (single-phase regeneration).
[0006] A well-known problem with such a prior art single-phase regeneration scheme is that significant amounts of soot may remain near the front and at the sides of the DPF. Soot located at the front end tends to burn slowly during regeneration because of relatively low exhaust gas temperature at the DPF inlet. On the other hand, soot farther along in the DPF burns faster because of cumulative heat generated upstream. By the end of the designated regeneration period, the front and side portions of a DPF typically are still covered in soot. This incomplete regeneration reduces the useful size and therefore the overall effectiveness of a DPF.
[0007] Due to the regeneration of DPF again and again, there are great probabilities of distortion of DPF. Moreover, the soot that is remained in the DPF will pass through the other components installed in the circuit of EGR (exhaust gas recirculation system) that results in the failure of various components.
OBJECTS OF THE DISCLOSURE
[0008] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed hereinbelow.
[0009] It is a general or primary object of the present disclosure is to provide the system that detects the condition of the DPF present inside the vehicle.
[0010] It is another object of the present disclosure is to identify the condition of the DPF by determining the pressure of the gas entering the inlet side of the compressor and the pressure of the gas exiting from the outlet of the DPF.
[0011] It is another object of the system to replace the DPF within the time period.
[0012] It is a further object of the present disclosure is to provide a low cost and efficient system that helps in detecting the condition of the DPF within a short span of time.
[0013] These and other objects and advantages will become more apparent when reference is made to the following description and accompanying drawings.
SUMMARY
[0014] This summary is provided to introduce concepts related to method and system for identification of a condition of a DPF installed in the vehicle. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0015] In an embodiment, the present disclosure relates to a diesel particulate filter safeguard system comprising an engine control unit (ECU) to retrieve from a data storage a first pressure sensor value measured by a first pressure sensor; periodically receive a pressure sensor value measured by a second pressure sensor mounted at or downstream an outlet of a diesel particulate filter (DPF); compare the second pressure sensor value with the first pressure sensor value; and ascertain the damage of the DPF when the second pressure sensor value is less than the first pressure sensor value.
[0016] In first implementation, the first pressure sensor and the second pressure sensor are a delta pressure sensor mounted at the outlet of the DPF. In this implementation, the ECU stores a reference value as the first pressure value based on previous measurements of a delta pressure sensor.
[0017] In second implementation, the first pressure sensor is mounted at one of an air inlet or an air outlet of an air compressor, while the second pressure sensor is mounted on an exhaust gas recirculation (EGR) pipe between the DPF and a filter mesh.
[0018] In an aspect of the second implementation, the present disclosure provides the system in which the filter mesh is of size equal to that of the DPF.
[0019] In an aspect of the second implementation, the present disclosure provides the system in which the filter mesh is positioned in between the DPF and EGR cooler.
[0020] In an aspect of the second implementation, the present disclosure provides the system in which the filter mesh is integrated with the EGR pipe.
[0021] In an aspect of the second implementation, the present disclosure provides the system in which the ECU provides an indication in a vehicle infotainment system about the damage of the DPF.
[0022] In an aspect of the second implementation, the present disclosure provides the system in which the ECU provides a damage indication about the damage of the DPF when the pressure difference between the second pressure sensor and the first pressure sensor value reaches a predefined value.
[0023] In another embodiment, the present disclosure further provides a method for safeguarding a diesel particulate filter. The method comprising the steps of retrieving, from a data storage of an engine control unit (ECU), a first pressure sensor value measured by a first pressure sensor; receiving periodically, at the ECU, a pressure sensor value measured by a second pressure sensor () mounted at or downstream an outlet of a diesel particulate filter (DPF); comparing the second pressure sensor value with the first pressure sensor value; and ascertaining the damage of the DPF when the second pressure sensor is less than the first pressure sensor value.
[0024] In a first implementation, the first pressure sensor and the second pressure sensor are a delta pressure sensor mounted at the outlet of the DPF. In this implementation, the ECU stores a reference value as the first pressure value based on previous measurements of a delta pressure sensor.
[0025] In a second implementation, the first pressure sensor is mounted at one of an air inlet or an air outlet of an air compressor, while the second pressure sensor is mounted on an exhaust gas recirculation (EGR) pipe between the DPF and a filter mesh.
[0026] In an aspect of the second implementation, the present disclosure provides a method used for installing the filter mesh of size equal to that of the DPF.
[0027] In an aspect of the second implementation, the present disclosure provides a method in which the filter mesh is positioned between the DPF and EGR cooler.
[0028] In an aspect of the second implementation, the present disclosure provides a method in which the filter mesh is integrated with the EGR pipe.
[0029] In an aspect of the second implementation, the present disclosure provides a method in which damage of the DPF is indicated to a vehicle infotainment system by the ECU.
[0030] In an aspect of the second implementation, the present disclosure provides a method in which the ECU defines the damage of the DPF when the pressure difference between the second pressure sensor and the first pressure sensor value reaches a predefined value.
[0031] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and methods that are consistent with the subject matter as claimed herein, wherein:
[0033] FIG.1 illustrates a circuit diagram of the EGR system of the diesel vehicle and the flow of gas through the various components present inside the EGR system in accordance with an embodiment of the prior art disclosure;
[0034] FIG.2 illustrates a circuit diagram of the EGR system of the diesel vehicle along with the DPF safeguard system used to detect the condition of DPF in accordance with an embodiment of the present disclosure;
[0035] FIG. 3 illustrates a block diagram of the diesel particulate filter safeguard system in accordance with an embodiment of the present disclosure; and
[0036] FIG. 4 illustrates a graph that shows the level of damage that happened inside the diesel particulate filter.
DETAILED DESCRIPTION
[0037] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0038] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0039] As per the conventional system, the user relies on their own judgment to decide when to change the DPF.
[0040] To overcome the issues related to the existing system, the present disclosure herein provides a system and a method that is used for detecting the condition of the DPF present inside the vehicle.
[0041] The present disclosure aims to solve a technical problem of detecting the condition of the DPF by placing the pressure sensor 1 before the compressor and the pressure sensor 2 after the DPF. If there is any pressure difference between the pressures measured by pressure sensor 1 and pressure sensor 2 then there are chances of DPF damage.
[0042] FIG.1 illustrates a circuit diagram of an EGR system 100 of the diesel vehicle and the flow of gas through the various components present inside the EGR system 100 in accordance with the prior art disclosure.
[0043] In the conventional EGR system 100 of the vehicle or the system disclosed in the prior art, the exhaust air enters through an air intake filter 102. After entering through the air intake filter 102, the exhaust air enters a compressor 104 that increases the pressure of the exhaust air and then half of the pressurized air enters an air charge cooler 106 that is cooled and further used as an intake air inside an engine 108. The remaining air is passed through a turbine 110 that reduces the pressure of the exhaust air. Nearly half of the exhaust air coming out of the engine 108 is recirculated by High Pressure (HP) EGR cooler 112 and HP EGR valve 124 and re-enter the engine 108. The exhaust air coming out of the turbine 110 is passed through a DPF 114, and a diesel oxidation catalyst (DOC), along with the exhaust air coming out of the engine 108. After that, all the soot particles present inside the exhaust air is absorbed by the DPF 114 and half of the exhaust air coming out of the DPF 114 is further passed through the exhaust or tailpipe 116, and the remaining exhaust air is further passed through a Low Pressure (LP) EGR cooler 118 and then to an LP EGR valve 120 that can be further used inside the EGR system 100.
[0044] However, as mentioned above, due to the regeneration of DPF again and again, there are great probabilities of distortion of DPF. Moreover, the soot that is remained in the DPF will pass through the other components installed in the circuit of EGR (exhaust gas recirculation system) that results in the failure of various components
[0045] To address this issue, a circuit diagram of an EGR system 200 of a diesel vehicle along with a DPF safeguard system used to detect the condition of the DPF in accordance with an embodiment of the present disclosure is shown in FIG. 2.
[0046] In a first embodiment of the EGR system 200 present in the present disclosure, the new components are introduced along with the already existing components that are the part of the DPF safeguard system used to check the condition of the DPF 114 is a first pressure sensor 204, 206 that is placed either at the air inlet or the air outlet of the compressor 104 to measure the pressure of the exhaust air entering the compressor 104 or going out of the compressor 104 and a second pressure sensor 208 placed at the outlet of the DPF 114 to measure the pressure of the exhaust air coming out of the DPF 114. If there is any difference in pressure, then the condition of DPF 114 is not good.
[0047] In a second embodiment of the EGR system 200 present in the present disclosure, the ECR system 200 includes a delta pressure sensor 207 mounted at the outlet of the DPF 114. The delta pressure sensor 207 keeps on monitoring the pressure of the exhaust air coming out of the DPF 114. Based on the previous measurements of the delta pressure sensor (207), the ECU 202 stores, in a data storage, one of the measured pressure values as a reference value in the form of the first pressure value. In one example, the data storage can be a part of ECU 202, or can be an independent unit connected though a communication network (not shown here). Once the first pressure value is retrieved by the ECU 202 as a reference value, the ECU 202 then receives the second pressure sensor value measured in real-time by the delta pressure sensor (207). Thereafter, the ECU 202 compares the second pressure sensor value with the first pressure sensor value, and ascertains the damage of the DPF (114) when the second pressure sensor value is found deviating from the first pressure sensor value.
[0048] All the pressure sensors 204, 206, 207, 208 are connected to an Engine Control Unit (ECU) 202 which receives the pressure values, compares these values, determines the condition of DPF 114 based on the comparison, and finally shows the condition of the DPF 114 on a vehicle infotainment system.
[0049] Moreover, in accordance with an implementation of the present disclosure, a filter mesh 210 of equal size to that of the DPF 114 is installed in the EGR pipe 122. Half of the exhaust air coming out of the DPF 114 is passed through the exhaust or the tailpipe 116 and the remaining exhaust air passing through the filter mesh 210 that cleans the soot that is remained in the exhaust air.
[0050] The filter mesh 210 is placed near the outlet of the DPF 114. Because of such placement of the filter mesh 210, self-cleaning of soot in the filter mesh 210 is performed due to the temperature raise in the DPF 114 for burning of soot. In this way, a user of the vehicle will safely increase the life of the DPF 114 by installing the filter mesh 210. Moreover, the user of the vehicle has to change only the DPF 114, not the filter mesh 210 as the filter mesh 210 is getting cleaned on its own.
[0051] FIG. 3 illustrates a block diagram of the diesel particulate filter (DPF) safeguard system in accordance with an embodiment of the present disclosure. In the DPF safeguard system, new components are introduced to check the condition of the DPF 114 that is the first pressure sensor 204, 206 which is placed either at the air inlet or the air outlet of the compressor 104 to measure the pressure of the exhaust air from the exhaust manifold entering the compressor 104 or going out of the compressor 104 (in FIG. 2, the first pressure sensor 204, 206 is placed at the inlet of the compressor 104) and the second pressure sensor 208 placed at the outlet of the DPF 114 to measure the pressure of the exhaust air coming out of the DPF 114. In an example, the first and second pressure sensors can be differential pressure sensors.
[0052] The pressures sensed by the first and second pressure sensors 204, 206, 208, are periodically communicated to the ECU 202. Based on the difference in pressure determined by the first and second pressure sensors 204, 206, 208, the ECU 202 ascertains the damage of the DPF 114 when the pressure sensor value of the second pressure 208 is found less than the pressure sensor value of the first pressure sensor 204, 206.
[0053] Further, as can be seen from FIG. 3, the filter mesh 210 of equal size of the DPF 114 is installed. Half of the exhaust air coming out of the DPF 114 is passed through the exhaust or the tailpipe 116 and the remaining exhaust air passing through the filter mesh 210 that cleans the soot that is remained in the exhaust air. The filter mesh 210 is placed near to DPF 114. So, during the regeneration of DPF 114 that is used to burn the soot accumulated inside the DPF 114, the soot inside the filter mesh 210 will be burnt successfully. After that, half of the exhaust gas released is passed through the exhaust or the tailpipe 116, and the remaining half is recirculated inside the EGR system through the LP EGR cooler 118 and LP EGR valve 120.
[0054] FIG. 4 illustrates a graph that shows a level of damage that could happen inside the diesel particulate filter (DPF) 114. In the Graph, X-axis shows a change in pressure difference determined by the ECU 202 by measuring the difference in pressure of the exhaust air entering inside the DPF 114 and exiting the DPF 114. This determines the condition of the DPF 114 and then a corresponding signal will be sent to the vehicle infotainment system by the ECU 202. For instance, when there is no damage in the DPF 114 as there is no change in pressure, the vehicle infotainment system shows no indication. Thereafter, when the pressure reaches a predefined value, the vehicle infotainment system shows a coloured light to indicate the damage in the DPF 114. Accordingly, the coloured light indication may be implement in the vehicle infotainment system to define the condition of the DPF 114.
[0055] Thus, with the system and the method described herein the present disclosure, various technical problems of the state of the art are resolved. Also, although a number of exemplary method options are described herein, those skilled in the art can appreciate that the system and the method that helps in detecting the condition of the DPF, without deviating from the scope of the subject matter of the present disclosure.
[0056] Further, it will be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the invention and are included within its scope.
[0057] Furthermore, all examples recited herein are principally intended expressly to be only for pedagogical purposes to aid the reader in understanding the principles of the invention and the concepts contributed by the inventor(s) to furthering the art and are to be construed as being without limitation to such specifically recited examples and conditions. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments.
[0058] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

Claims:1. A diesel particulate filter safeguard system comprising:
an engine control unit (ECU) (202) to:
retrieve from a data storage a first pressure sensor value measured by a first pressure sensor (204, 205; 207);
periodically receive a pressure sensor value measured by a second pressure sensor (208; 207) mounted at or downstream an outlet of a diesel particulate filter (DPF) (114);
compare the second pressure sensor value with the first pressure sensor value; and
ascertain the damage of the DPF (114) when the second pressure sensor value is less than the first pressure sensor value.
2. The system as claimed in claim 1, wherein the first pressure sensor (207) and the second pressure sensor (207) being a delta pressure sensor (207) mounted at the outlet of the DPF (114).

3. The system as claimed in claim 2, wherein ECU (202) stores a reference value as the first pressure value based on previous measurements of the delta pressure sensor (207).

4. The system as claimed in claim 1, wherein the first pressure sensor (204, 206) is mounted at one of an air inlet or an air outlet of an air compressor (104).

5. The system as claimed in claim 4, wherein the second pressure sensor (208) is mounted on an exhaust gas recirculation (EGR) pipe (122) between diesel particulate filter (DPF) (114) and a filter mesh (210).
6. The system as claimed in claim 5, wherein the filter mesh (210) is of size equal to that of the DPF (114).

7. The system as claimed in claim 5, wherein the filter mesh (210) is positioned between the DPF (114) and EGR system components.
8. The system as claimed in claim 5, wherein the filter mesh (210) is integrated with the EGR pipe (122).

9. The system as claimed in claim 1, wherein the ECU (202) provides an indication at a vehicle infotainment system about the damage of the DPF (114).

10. The system as claimed in claim 9, wherein the ECU (202) provides an indication about the damage of the DPF (114) when the pressure difference between the second pressure sensor and the first pressure sensor value reaches a predefined value.

11. A method for safeguarding a diesel particulate filter (114), the method comprising
retrieving, from a data storage, a first pressure sensor value measured by a first pressure sensor (204, 206; 207);
receiving periodically a pressure sensor value measured by a second pressure sensor (208; 207) mounted at or downstream an outlet of a diesel particulate filter (DPF) (114);
comparing the second pressure sensor value with the first pressure sensor value; and
ascertaining the damage of the DPF (114) when the second pressure sensor is less than the first pressure sensor value.
12. The method as claimed in claim 11, comprising storing, in the data storage, a reference value as the first pressure value based on previous measurements of the first pressure sensor (207), the first pressure sensor and the second sensor being a delta pressure sensor (207) mounted at the outlet of the DPF (114).

13. The method as claimed in claim 11, wherein the first pressure sensor (204, 206) is mounted at one of an air inlet or an air outlet of an air compressor (104).

14. The method as claimed in claim 13, wherein the second pressure sensor (208) is mounted on an exhaust gas recirculation (EGR) pipe (122) between diesel particulate filter (DPF) (114) and a filter mesh (210).

15. The method as claimed in claim 14, wherein the filter mesh (210) of size equal to that of the DPF (114).

16. The method as claimed in claim 14, wherein the filter mesh (210) is positioned between the DPF (114) and EGR cooler (118).
17. The method as claimed in claim 14, wherein the filter mesh (210) is integrated with the EGR pipe (122).

18. The method as claimed in claim 8, comprising indicating damage of the DPF (114) to a vehicle infotainment system when the pressure difference between the second pressure sensor and the first pressure sensor value reaches a predefined value.