Design And Test Of Regenerative Control Strategy For Diesel Particulate Filters

The problems of vehicle emissions influence environmental quality was widely focused on by many countries in the world day and day.Our countries lay down increasingly stringent emission regulation in recent years.It is difficult to make the exhaust emissions of vehicles to achieve the latest emissions regulations only by purifying the engine machine,as after-treatment technology is needed.Diesel Particulate Filter(DPF)are considered to be the most effective means of reducing particulate matter emissions from modern diesel engines.Particulate matter collected in the trap needs to be regularly removed from the porous wall by means of oxidation,so as to avoid excessive exhaust back pressure and negative effects of the engine and turbocharger resulting in excessive fuel consumption.Diesel Oxidation Catalyst(DOC)can effectively reduce hydrocarbon emissions and provide a suitable combustion environment for DPF to increase particle regeneration rates.The work of this paper comes from the engineering needs of Chongqing CVS Environmental Protection Technology Co.Ltd.On the basis of DOC and DPF after-treatment system,study on a full set of control strategy for the DPF can be safe and effective regeneration.In this paper,the author analyses mainstream technology of regeneration control at home and abroad based on the current domestic fuel condition and technical level of the diesel engine,we ultimately chose the way of fuel injection assisted-regeneration.For the general structure of after-treatment regeneration control system provided by CVS,designed a complete regeneration control strategy by after-treatment system performance simulation of key components in use of AVL BOOST.Designed electronic control unit,including hardware circuit、lower computer software and upper computer software,based on the system structure and control strategy of regenerative.In order to verify whether the control strategy can be safe and effective regeneration,we built a bench test system in the Emission Testing Center of China Automotive Engineering Research Institute and used the electronic control system to make the after-treatment regeneration control system and diesel engine work together.The test shows that the temperature rise characteristic of DOC and the DPF regeneration temperature control was pretty much in line with expectations.At last,we calculate the regeneration rate is 94% by removing DPF carrier measurement comparison.The paper mainly completed the following work.Firstly,according to the general structure of DPF control system provided by CVS,a technical solution was developed,key parameters were obtained through simulation,and a complete regeneration control strategy was designed.Secondly,according to DPF regeneration control unit hardware design scheme,DPF regeneration control unit software design scheme and regeneration control strategy,hardware design,lower computer software design and upper computer software design are completed.Thirdly,on the diesel engine test bench system,the electronic control unit has been used to control the DPF after-treatment system to work cooperatively with the diesel engine to complete the entire regeneration control process.