Patent attributes
In an exhaust gas purifying technique in which discharge is utilized, the invention provides a technique in which purification efficiency can be enhanced while an increase in electric power consumption is suppressed. A discharge mode including a discharge period and an undischarged period is adopted in a configuration in which a plasma process is performed to exhaust gas from a Diesel engine by generating the discharge in a plasma generator. A basic waveform periodically exists in a repeated manner in the discharge period, and the discharge is not performed in the undischarged period. An amplitude and/or a period of the basic waveform is controlled according to a load on the Diesel engine, a continuous iteration count of the basic waveform is controlled according to purification reaction efficiency in the plasma process, and the burst period is controlled according to an exhaust gas flow rate.
