Designing And Modeling Of Onboard Refueling Vapor Recovery System & Experiment Research

It is well known that the amount of the vehicles is fast increasing and coming with the increasing gasoline consumption. Because of the gasoline vaporing characteristic, the amount of the gasoline vapor is enormously increasing. So the amount of the refueling vapor emissions of gasoline is also increasing. According to forecasting, the amount of the refueling vapor emission will increase from 105397.11 tons in 2008 to 616167.72 tons in 2025. It is very important to do some research of vapor emissions mechanism during refueling gasoline vehicles and design a system to effectively recovering refueling vapor emissions.Firstly, the rule of law and emission guideline of foreign has been analyzed. And the shortcoming of the domestic vapor recovery system has been analyzed, then according to solution to these shortcomings, measurements has been brought forward. At last the onboard refueling vapor recovery system (ORVR) has been introduced and the mechanism of recovering refueling emissions of ORVR has been introduced in detail. And then the designing scheme and the measurements of the main parts of ORVR have been listed in detail in this paper.In order to check if ORVR could reduce the refueling emission of gasoline vehicle effectively after installing ORVR, mathematical models of refueling vapor emissions have been modeled in the chapter 4 and chapter 5 respectively with only installing canister carbon and installing ORVR according to mass transfer principle. With these mathematical models, refueling vapor emissions have been predicted and compared with the experiment data and proofed that the experiment data and the predicted data of mathematical were fitted closely. According to analysis, following with higher average temperature of gasoline tank and fuel dispensing into gasoline tank, and bigger Reid vapor pressure of gasoline as well as more air entrained into oil tank etc, refueling emissions of automobile increased.At last, in order to proof the recovery efficiency of refueling vapor emissions with ORVR, experiment methods have been designed:one is canister carbon trap method, another is sealed housing for evaporative determinations method. And then three refueling conditions have been done with these two experiment methods: (1)Refueling emissions experiment of tank without installing carbon canister and ORVR; (2) Refueling emissions experiment of tank with only installing carbon canister but without installing ORVR; (3) Refueling emissions experiment of tank with both installing carbon canister and installing ORVR. The results of the experiments is indicated that refueling emissions can be reduced by about 15.7% with only installing carbon canister; and refueling emissions can be reduced by average above 94% with installing carbon canister and ORVR system.