The decision on whether, and if so when, regeneration has to take place must be made by two different software applications:
• Supervisor software
• Manager software
1. Supervisor software
2. Manager software
4. Regeneration is to take place
5. Monitoring of the regeneration
The Supervisor software decides on the basis of the following parameters whether regeneration should be carried out:
• Soot load of the diesel particulate filter (value of the
DPF differential pressure sensor),
• Distance travelled
• Operating conditions
• Favourable conditions for regeneration
• Probability of improved conditions in the near future.
By taking these parameters into account, it is possible to achieve minimum fuel consumption levels, minimum oil dilution and optimum performance whilst the vehicle is being driven.
If the supervisor software makes the decision that regeneration should be carried out, the manager software is informed.
The Manager software monitors the regeneration process and constantly interrogates the following inputs:
• Coolant Temperature
• Fuel Temperature
• Exhaust Gas Temperature
• Manifold Absolute Pressure.
After the supervisor software has enabled regeneration, the following actuations occur in two stages:
• Shut-off of the EGR system
• Actuation of the turbocharger guide vanes to deliver maximum boost pressure
• Closing of the throttle intake valve
• Advanced post-injection
• Retarded post-injection.
If regeneration has commenced it will be completed, regardless of the operating condition of the engine. Regeneration can only be stopped by shutting off the engine. Regeneration is started again once acceptable operating conditions are detected by the system.
Regeneration takes a maximum of 20 minutes"-
The post-injections result in high oil dilution and must therefore be kept within limits.
To avoid excessively high oil dilution, a minimum driving distance has to be maintained between two regeneration cycles approx. 217 miles (350 km).
Note: Increased oil consumption and reduced fuel quality (high sulfur content), as well as high fuel consumption accelerate the build-up of ash in the DPF, shortening regeneration intervals more quickly.
If the minimum distance between regeneration cycles, currently 217 miles (350 km), cannot be adhered to, this is detected by the diesel particulate differential pressure sensor, and the DPF warning is switched on. The DPF will require a drive cycle forced by the WDS.