The effect of different regeneration temperature and input exhaust flow rate on particulate emissions from a diesel particulate filter(DPF) were studied using an externally heated regeneration performance test bench. The test results showed that when the amount of particle loaded for the bench test was 2.5g/L

the number of particle concentration at the DPF outlet appeared one peak

and when the particle loading was 5.0g/L

two peaks appeared. At the same input exhaust flow rate

the regeneration efficiency and the total particle mass concentration increased with the rise of regeneration temperature. At this time

the outlet particles at the heating stage were mainly in the nucleation mode

and during the regeneration stage

a temperature peak appeared in the DPF

and the particles from the DPF outlet were mainly in the accumulation mode with a diameter of 50nm or more. At the same regeneration temperature

when the particle loading was 2.5g/L

the regeneration efficiency and the total particle mass concentration increased with the rise of input exhaust flow rate. At this time

the outlet particles at the heating and regeneration stages were mainly in the nucleation mode. When the particle loading was 5.0g/L

the regeneration efficiency and the total particle mass concentration tended to increase first and then decrease as the input exhaust flow rate increased. At this time

the outlet particles at the heating stage were mainly in the nucleation mode

while at the regeneration stage

some accumulative particles were discharged at high exhaust flow rate.