| Summary: | 碩士 === 國立中興大學 === 機械工程學系 === 88 === The main function of remote sensing devices is to screen highly emitted vehicles, and thus reduces the testing cost and time. Since 1996, the ROCEPA started the remote sensing program in Taiwan. A total of 1.8 millions data have been collected in the 1999 remote sensing program. The objective of this study was to analyze these data to find out the characteristics of vehicle emissions in Taiwan.
Only a very small portion of the original data were screened out using the criteria based on combustion principles. The emission data can be described statistically with a gamma distribution. Vehicles less than 7 years old constituted 75% of the vehicle population, and the 1995 model year vehicles were ranked as the most popular model year. Results of analysis showed that old vehicles had higher emission concentrations than the new vehicles. However, the emitting ratio of new vehicles was higher than the old, because the new vehicles had more mileage and population. The emitting ratio of 4~7 years old vehicles was up to 40% of the total emissions. Besides, the vehicles in the top 10% of emitting rates contributed about 49.2% of the total emissions. As for the contributions from the automobile manufacturers, the TOYOTA was ranked as the lowest, and the FORD was ranked as the highest. However, discrepancies in emission concentrations between different manufactures became insignificant after 1993.
The location of testing could affect the results of measuring. Besides, the reproduction of data were not good no matter these data were collected at the same location or at different locations. It is recommended that in order to find out the high emission vehicles, at least two measured data were required in the screening process.
The emission characteristics of LPG vehicles were also investigated in this study. Results of comparisons between emissions of LPG vehicles and that of gasoline vehicles showed that LPG vehicles emitted more pollutants than the gasoline vehicles.
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