Occurrence of the error of P2002, which indicates the low efficiency of FAP/DPF, as well as indication on the instrument panel. In case of FAP/DPF filter breakdown the power reduces, instability of engine running appears, fuel consumption increases and smoke increases.
The following sign of malfunction is increase of oil level. If the particulate filteris dirty, the control unit tends to turn the regeneration mode on. In this case more fuel run into engine in order to hit higher temperature of exhaust gases, which results in partial combustion of soot accumulated on theparticulate filter. However, increased pressure also promotes fuel to run into the crankcase. It may result in engine breakdown, therefore we don’t recommend to operate the car in such situation!
Originally diesel particulate filtersand catalyst were designed for Europe countries, in which there are strict standards for fuel. We often pay no regard for them. Low-quality fuel accelerates process of contamination and depreciation of theparticulate filter.
Cleaning of the particulate filters(repair) provides short-term results.
Melted particulate filter.
Principle of operation of the particulate filter (FAP / DPF)
Particulate filter is a matrix structure of ceramics (silicon carbide), enclosed in metal casing. All matrix cells are parallel located channels which are alternately opened and closed on the one side (inlet and outlet), separated by filter walls, which are covered by zirconium and aluminum oxides. These filter walls act as a catalyst support, which promotes reaction chemical behavior, but thus does not form new compounds and does not change itself. As the filter has porous structure with alternately closed channels, waste gases pass through porous walls and soot particles in inlet valves.
Diesel particulate filter (DPF) is enclosed-type filter. When exhaust gases pass through it, small soot particles (0,1-1 microns) are retained. As these filters have no automatic regeneration system, it is necessary to periodically clean the particulate filter. Otherwise, error P2002 with all consequences may occur.
Particulate filter with automatic regeneration (FAP) in exhaust system is installed behind the catalyst converter. Regeneration occurs due to injection of special additive in the fuel, which increases the temperature of exhaust gases. When filling the particulate filter the control unit sends a signal to inject the additive containing zirconium, thanks to which the temperature of waste gases increases and the filter is heated to required temperatures. Under the influence of such temperature the soot burns down.
The majority of modern diesel cars have diesel particulate filter, combined with an oxidizing catalyst, which is located in front part of the filter. He performs the functions of filter FAP/DPF and catalyst.
For provision of ceaseless mode of particulate filter operation many sensors are used in control system, which are absent in a gasoline engine.
- Instrument panel
- Electrical control unit
- Mass airflow sensor (MAF)
- Diesel engine
- Temperature sensor in front of the turbine
- Turbine
- Temperature sensor in front of the particulate filter
- Oxygen sensor
- Particulate filter (FAP / DPF)
- Pressure differential sensor on the particulate filter
- Temperature sensor behind the particulate filter
FAP / DPF particulate filter behind the turbine is installed in immediate proximity of the motor.
Regeneration
The soot is accumulated in the filter during operation of the car, it adversely affects the engine running. The excessive quantity of the soot in the filter promotes high pressure in the system and prevents waste gas exhaust.
Therefore, the process of regeneration is necessary.
There are passive and active regeneration.
Types of regeneration, depending on the filling degree of the FAP / DPF filter
Passive regeneration
Passive regeneration occurs without any intervention in the control system. It is possible, if load on the engine is sufficient (above average), at this conditions more fuel is injected to the engine, thus waste gas temperature increases. The temperature increase promotes partial combustion of soot. The process of the passive regeneration is affected by catalyst which promotes reaction chemical behavior – conversion of soot to carbon dioxide.
In urban mode and especially in long traffic jams, passive regeneration is practically reduced to «0», resulting particulate filter quickly become unusable. The removal of particulate filter (FAP / DPF) is the right decision in such a situation.
Active regeneration
Active regeneration is created with the use of the task-oriented control of diesel engine, at which the temperature of 600-650 Cis achieved. In order to raise the temperature up to this limit control system performs the following actions:
- Waste gas recirculation is stopped, thereby the temperature of fuel combustion increases
- Additional portion of the fuel is injected in the engine at fuel injection stroke
- Air supply to the engine is reduced;
- Additional injection of fuel is made on waste gas exhaust stroke, at this fuel and exhaust gases pass to FAP / DPF particulate filter and combust in it;
- Charging pressure is changed and maintained at such level at which the driver do not notice transition to the regeneration mode.
Emulator SK 05 – function principle
Emulator of particulate filter precisely repeats all sensor signals that are received in working mode of the device. With the help of a three-dimensional model, SK-05 recreates all physical and chemical processes that occur in the filter.
Signals of pressure and temperature differential sensors are formed. At this the following factors are considered:
- Waste gas temperature;
- Air flow in the system;
- Heat capacity of the particulate filter;
- Thermodynamics of the original exhaust system of waste gas;
- The effect of chemical processes occurring in the particulate filter on the readings of the sensors;
- Monitoring of the regeneration beginning;
- The behavior of the filter during regeneration is emulated and the degree of filling is increased.
Emulator particulate filter is completely ready for operation upon delivery.
We provide our dealers and representatives with software that allows you to create a behavioral model for any car brand. To simplify this task there is a self-learning function, due to which the emulator can partially configure for this model itself.
The software allows you to copy and transfer developed behavioral models for any car, record and store all parameters related with FAP / DPF filter in real-time mode.