Summary: | 碩士 === 國立中興大學 === 機械工程學系 === 88 === Due to lower Exhaust Emission, the LPG vehicle is more helpful to improve the deteriorated air quality than gasoline vehicle, especially in the urban area. Recently, all LPG application was used in the automobile issue, not in motorbike. However, in the urban area, motorbike was more influential for air pollution than automobile.
The following article is mentioned about experiment of engine and test of altered motorbike. New fuel system will be designed in this article as well. The new fuel system will be tested on the dynamometer, firstly and then on the exhaust emission of LPG motorbike, which was included the controlled CO, HC, NOX and other harmful but uncontrolled gas. From the result, it will offer more effective standard for evaluating air quality in the urban area, where was replaced using LPG in motorbike.
The workings in this experiment are (1). Design of LPG fuel system. (2). Test of altered motorbike. (3). Measure of exhaust emission in LPG motorbike. Designs of fuel system are included: fuel tank, fuel wire system, LPG reduced pressure valve, evaporator, flow control valve, mixer design and fuel temperature control system. In the exhausted gas composition, HC was analyzed by GC/MS. The burned gasoline was with 21% of ethylene, 11% of 1-propene, 2-methyl, 8% of propene and 7% of ethane. The burned LPG was with 62% of propane, 11% of ethylene, 9% of n-butane and 6% of ethane. Therefore, the OFP (Ozone Forming Potential) of LPG engine was 20% lower than that of gasoline engine.
Results of experiments showed that there is no significant difference in torque and power between LPG engine and gasoline engine in low and medium RPM. But, in high RPM, the performance curve of LPG engine was 27% lower than that of gasoline engine. Furthermore, the CO and HC emission in the waste gas was not as good as gasoline engine. The main reasons were the effect of fuel property and that the fuel system and mixer did not function well.
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