Comparison of Evaporative Emissions of Hybrid Vehicles Equipped with NIRCO System Under National and European Standards (Euro 6D)

Abstract

In order to control the level of evaporative emissions, more and more hybrid vehicles are adopting the Non-Integrated Refueling Canister Only system (NIRCO). This paper compares and analyzes the evaporative emission regulations of the Sixth National Standard and the European Standard (Euro 6D), and obtains the similarities and differences in regulatory requirements and testing requirements. The main differences are the aging process of carbon canisters and the treatment methods of carbon canisters during vehicle testing. The evaporative emission tests were conducted using the same vehicle under the requirements of the National VI B and European Standard (Euro 6D) regulations. The results showed that after the carbon canister had undergone the aging required by the European VI D regulations, the degree of aging of the canister was greater and the working capacity decreased more severely. The final evaporative emission results of the vehicle under the European standard (Euro 6D) are slightly higher than the evaporative emission results of National VI B, which puts higher requirements on the fuel system and vehicle manufacturers.