US-12618354-B2 - Method and system for detecting and quantifying regeneration events in a diesel particulate filter

US12618354B2US 12618354 B2US12618354 B2US 12618354B2US-12618354-B2

Abstract

Methods and Systems are provided for detecting and quantifying regeneration events for diesel particulate filters in diesel engines. Parameters such as exhaust temperature, DPF differential pressure, and mass flow rates received from an engine management system are checked to determine if a regeneration is detected. If a regeneration event is detected, DPF differential pressures are logged and identified as pre-event differential pressures or post-event differential pressures. A soot burn quality value is determined using the pre-event and post-event differential pressures. The soot burn quality is used to score the soot burn and to generate alerts.

Inventors

Harleen Kaur Bagga
Bhushan Dayaram Patil
Abhijit Vishwas Patil
Hariharan Ravishankar
Vikram Reddy Melapudi
Nikhil Gore
Nishant Srivastava
Ruchika Sharma
Aman Singh

Assignees

INTANGLES LAB PVT. LTD.

Dates

Publication Date: 20260505
Application Date: 20240228

Claims (20)

1 . A system for detecting and quantifying regeneration in a diesel particulate filter configured to trap particulates in engine exhaust gas, the system comprising: a data interface configured to receive engine data from an engine management system configured to receive a plurality of parameters from sensors that monitor the parameters indicative of engine operation, where the parameters include differential pressure across the diesel particulate filter (“DPF”), exhaust temperature, and mass flow rate; a diesel particulate filter diagnostic system (“DPF diagnostic system”) stored as computer programs in a memory system; and a processor configured to execute the computer programs of the DPF diagnostic system, where when executed the DPF diagnostic system: receives and stores a plurality of DPF differential pressure measurements, engine speed, and engine load read by the engine management system periodically at predetermined sampling intervals during engine operation; detects a regeneration event by continuously monitoring when the exhaust temperature exceeds a regeneration temperature threshold of 500° C. and the mass flow rate exceeds a regeneration gas flow threshold of 300 kg/hr, where at least one DPF differential pressure measurement stored before detection of the regeneration event is stored as a pre-event differential pressure; stores at least one DPF differential pressure measurement received after completion of the regeneration event as a post-event differential pressure; calculates a soot burn quality=[(pre-event differential pressure−post-event differential pressure)/pre-event differential pressure]×100% to quantify actual soot removal efficiency during the regeneration event; scores the soot burn quality based on predetermined threshold levels where a bad soot burn is less than 33%, a medium soot burn is 33% to 66%, and a good soot burn is greater than 66%; and automatically controls engine operating parameters by outputting a DPF status based on the score to the engine management system to trigger corrective actions including initiating addition regenerating cycles when the soot burn quality indicates poor DPF performance.
2 . The system of claim 1 where the scoring of the soot burn quality includes determining: a bad soot burn for a soot burn quality <33%, a medium soot burn for a soot burn quality >=33% and <66%, AND a good soot burn for a soot burn quality >=66%.
3 . The system of claim 1 where the DPF diagnostic system: generates an alert indicative of the soot burn quality, and where the soot burn quality and post-event differential pressure are evaluated to generate an alert as a major or a minor issue.
4 . The system of claim 2 where: when the bad soot burn quality is bad soot burn or medium soot burn, a major issue alert is generated when the post-event differential pressure is greater than a HIGH POST-EVENT DIFFERENTIAL PRESSURE THRESHOLD; and when the soot burn quality is bad soot burn, and the post-event differential pressure is between a LOW POST-EVENT DIFFERENTIAL PRESSURE THRESHOLD and the HIGH POST-EVENT DIFFERENTIAL PRESSURE THRESHOLD, a minor issue alert is generated.
5 . The system of claim 1 where in detecting the regeneration event, the DPF diagnostic system: determines a passive event time during which the regeneration temperature exceeds 500° C. and mass flow rate exceeds 300 kg/hr, which are indicative of the regeneration event; and stores the pre-event differential pressure and the post-event differential pressure for the regeneration event when the passive event time is greater than a predetermined regeneration event threshold time.
6 . The system of claim 1 where the DPF diagnostic system: stores for each regeneration event a regeneration event data set comprising: the differential pressure, the soot burn quality, the soot burn score, and the exhaust temperature during the regeneration event; stores a regeneration event sequence comprising the regeneration event data sets for each regeneration event in a time period, where each regeneration event data set is time-stamped.
7 . The system of claim 1 where the DPF diagnostic system: stores a clean state differential pressure determined in a clean regeneration event when the DPF is in a known clean state; and calculating a soot burn load for each regeneration event by subtracting the differential pressure calculated at each regeneration event from the clean state differential pressure.
8 . The system of claim 1 where the DPF diagnostic system: compares the pre-event differential pressure−the post-event differential pressure to a VALID EVENT THRESHOLD; and indicates a failed regeneration when the pre-event differential pressure−the post-event differential pressure is less than the VALID EVENT THRESHOLD.
9 . The system of claim 1 where the DPF diagnostic system: calculates a pre-event fuel consumption before the regeneration event; calculates a fuel consumption during the regeneration event; and indicates the fuel consumption during regeneration as a fuel loss when the DPF diagnostic system indicates a failed regeneration, or indicates the fuel consumption as a fuel efficiency improvement when the DPF diagnostic system does not indicate a failed regeneration.
10 . A method of detecting and quantifying regeneration in a diesel particulate filter comprising: receiving from an engine management system over a data interface a plurality of DPF differential pressure measurements, engine speed, and engine load read by the engine management system periodically at predetermined sampling intervals during engine operation, and storing the plurality of DPF differential pressure measurements, engine speed, and engine load in a data storage; detecting, using a processor, a regeneration event by continuously monitoring when the exhaust temperature exceeds a regeneration temperature of 500° C. and the mass flow rate exceeds a regeneration gas flow threshold of 300 kg/hr, where at least one DPF differential pressure measurement stored before detection of the regeneration event is stored as a pre-event differential pressure; storing, in the data storage system, at least one DPF differential pressure measurement received after completion of the regeneration event as a post-event differential pressure; calculating, using the processor, a differential pressure by subtracting the post-event differential pressure from the pre-event differential pressure; calculating a soot burn quality=[(pre-event differential pressure−post-event differential pressure)/pre-event differential pressure]×100% to quantify actual soot removal efficiency during the regeneration event; scoring the soot burn quality based on predetermined threshold levels where a bad soot burn is less than 33%, a medium soot burn is 33% to 66% od soot burn is greater than 66%; and automatically controlling engine operating parameters by outputting a DPF status based on the score to the engine management system to trigger corrective actions including initiating additional regeneration cycles when the soot burn quality indicates poor DPF performance.
11 . The method of claim 10 where the scoring of the soot burn quality includes determining: scoring a bad soot burn for a soot burn quality <33%, scoring a medium soot burn for a soot burn quality >=33% and <66%, AND scoring a good soot burn for a soot burn quality >=66%.
12 . The method of claim 10 where the step of outputting the DPF status includes: generating an alert indicative of the soot burn quality.
13 . The method of claim 11 further comprising: evaluating the soot burn quality and post-event differential pressure to generate an alert as a major or a minor issue.
14 . The method of claim 13 further comprising: generating a major issue alert when the bad soot burn quality is bad soot burn or medium soot burn, and when the post-event differential pressure is greater than a HIGH POST-EVENT DIFFERENTIAL PRESSURE THRESHOLD; and generating a minor issue alert when the soot burn quality is bad soot burn, and the post-event differential pressure is between a LOW POST-EVENT DIFFERENTIAL PRESSURE THRESHOLD and the HIGH POST-EVENT DIFFERENTIAL PRESSURE THRESHOLD.
15 . The method of claim 10 where in detecting the regeneration event, the DPF diagnostic system: determines a passive event time during which the regeneration temperature exceeds 500° C. and mass flow rate exceeds 300 kg/hr are indicative of the regeneration event; and stores the pre-event differential pressure and the post-event differential pressure for the regeneration event when the passive event time is greater than a predetermined regeneration event threshold time.
16 . The method of claim 10 comprising: storing for each regeneration event a regeneration event data set comprising: the differential pressure, the soot burn quality, the soot burn score, and the exhaust temperature during the regeneration event; storing a regeneration event sequence comprising the regeneration event data sets for each regeneration event in a time period, where each regeneration event data set is time-stamped.
17 . The method of claim 10 comprising: storing a clean state differential pressure determined in a clean regeneration event when the DPF is in a known clean state; and calculating a soot burn load for each regeneration event by subtracting the differential pressure calculated at each regeneration event from the clean state differential pressure.
18 . The method of claim 10 comprising: comparing the pre-event differential pressure−the post-event differential pressure to a VALID EVENT THRESHOLD; and indicating a failed regeneration when the pre-event differential pressure−the post-event differential pressure is less than the VALID EVENT THRESHOLD.
19 . The method of claim 18 comprising: calculating a pre-event fuel consumption before the regeneration event; calculating a fuel consumption during the regeneration event; and indicating the fuel consumption during regeneration as a fuel loss when the DPF diagnostic system indicates a failed regeneration, or indicating the fuel consumption as a fuel efficiency improvement when the DPF diagnostic system does not indicate a failed regeneration.
20 . The method of claim 10 comprising: quantifying a quality measure of the regeneration quantification by evaluating the differential pressure pre-regeneration and the differential pressure post-regeneration, where a larger drop in differential pressure is indicated as good regeneration and a smaller drop in differential pressure is indicated as a bad regeneration; identifying a failed regeneration event when an insignificant drop in differential pressure is measured and other parameters indicate a regeneration event where the exhaust temperature exceeds 500° C. and the mass flow rate exceeds 300 kg/hr; evaluating fuel efficiency after the regeneration event by: reporting a fuel efficiency loss when the regeneration event is identified as failed regeneration event with soot bum quality smaller than 33%; reporting a fuel efficiency improvement when a good regeneration event is identified with soot burn quality greater than 66%; mapping the sequence of regeneration quantification and change in the fuel efficiency to a DTC event relating to the DPF indicated by the engine management system; anticipating a DPF clogging before the DTC event is generated by analyzing the mapping of the sequence of regeneration quantification and change in fuel efficiency and automatically triggering corrective engine control actions to prevent DPF failure; indicating an alert before the DPF clogging; displaying at least one suggested action to avoid the DPF clogging; and simultaneously providing a fuel efficiency reduction due to a current clogging state of the DPF.

Description

BACKGROUND This disclosure relates generally to diesel engines and more particularly to diesel particulate filter regeneration analysis. Diesel engines are typically equipped with a diesel particulate filter (DPF) in the exhaust systems. The DPF is a filter that captures and stores exhaust soot in order to reduce harmful emissions from diesel vehicles. DPFs are disposed in line with the exhaust path of the diesel engine to trap al of the soot from the engine. DPFs have a finite capacity for the volume of soot that can it can trap. A process called regeneration or soot oxidation or soot burn can be performed to burn-off or empty the trapped soot. A regeneration generally entails running the engine at a high load in order to increase the engine temperature enough to burn off the excess soot trapped in the DPF. A regeneration may be performed in the following ways: Passive Regeneration: Soot is burned off from the DPF without engine control unit (“ECU”) intervention, typically occurring at higher engine loads. Active Regeneration: When the ECU actively increases exhaust temperature (500-650° C.) to burn off soot. Active regeneration may be viewed as a process initiated by the engine to ensure that the DPF is cleaned. Regeneration may be initiated based on a threshold differential pressure, a threshold soot load, or periodically. Parked Regeneration: Drivers can initiate parked regeneration by parking the vehicle and engaging a switch, causing the engine to rev up and increase exhaust temperature to burn off soot. Forced Regeneration: Technicians at a shop can perform forced regeneration by connecting to the vehicle via a laptop/diagnostic tool. Forced, active and parked regenerations may be initiated by the ECU by controlling engine parameters expected to increase the engine temperature. Such parameters include, for example, engine speed or engine load. In some cases, the ECU may initiate a process in which fuel is injected into the DPF structure to increase the burn temperature. Regeneration is most efficiently performed at temperatures between about 500° and 650° C. Passive regenerations and even active regenerations may not always achieve the right temperature and other factors may affect the quality of soot burns. This can result in uncertainty in the remaining effectiveness of the DPF in any given diesel engine. As diesel engines age, the regeneration process becomes less and less effective. It may not be possible to completely burn off all of the soot in any given regeneration either because it has accumulated over time, or because the quality of individual soot burns are not consistently good, which may be due to an inability to consistently reach a sufficiently high engine temperature. An aging DPF may result in a loss of fuel efficiency, engine power, and overall engine performance as the DPF becomes more and more clogged. While regeneration events may extend the life of the DPF, there is currently no way to monitor the effectiveness of the regeneration process over the life of the engine. SUMMARY In example implementations described in this disclosure, systems and methods are provided for detecting and quantifying regeneration in a diesel particulate filter configured to trap particulates in engine exhaust gas. In example implementations, the system includes a data interface configured to receive engine data from an engine management system configured to receive a plurality of parameters from sensors that monitor the parameters indicative of engine operation. The parameters include differential pressure across the diesel particulate filter (DPF differential pressure), exhaust temperature, and mass flow rate. A diesel particulate filter diagnostic system (“DPF diagnostic system”) is included and stored as computer programs in a memory system. A processor executes the computer programs of the DPF diagnostic system, where when executed the DPF diagnostic system: receives and stores a plurality of DPF differential pressure measurements, engine speed, and engine load read by the engine management system periodically;detects a regeneration event when the exhaust temperature is greater than a regeneration temperature threshold and the mass flow rate is greater than a regeneration gas flow, where at least one DPF differential pressure measurement stored before detection of the regeneration event is stored as a pre-event differential pressure;stores at least one DPF differential pressure measurement received after completion of the regeneration event as a post-event differential pressure;calculates a differential pressure by subtracting the post-event differential pressure from the pre-event differential pressure;calculates a soot burn quality=[(pre-event differential pressure−post-event differential pressure)/pre-event differential pressure]×100%;scores the soot burn quality based on predetermined threshold levels; andoutputs a DPF status based on the score. In one aspect, the scoring of the soot burn qualit