An emission reduction system that uses secondary air injection and a catalyst was developed to meet emission standards for domestic gasoline engine generators enacted by India in 2014.Gasoline engine generators require a compact size and high portability, so there are many restrictions on the exhaust system layout, and it has been a challenge to realize secondary air injection using the exhaust pulsation effect.This development discovered the proper exhaust pipe and secondary air pipe lengths that increase the pulsation effect of the secondary air pipe, and realized a compact system that complies with both emission and generator noise standards and fits within the mass-production generator chassis.In addition, regarding emission measurement methods, the raw gas measurement method and dilute gas measurement method were compared and verified, and a measurement method that does not influence the secondary air quantity was found.
Article of Honda R&D Technical Review Vol.27 No.2 (30 - 36)