不同海拔下柴油机燃用生物柴油的噪声频谱特性研究

Study on Characteristics of the Noise Spectrum of Diesel Engine Burning Biodiesel under Different Altitudes

在高原环境下,使用大气模拟试验台测试了4100QB-2柴油机在不同大气压下燃用不同体积掺混比生物柴油/柴油混合燃料的噪声,并进行了频谱特性分析。试验结果表明,使用相同燃油时,噪声的声功率级随负荷和转速的增加而增加,随大气压力的增加而减小;相同工况下,随燃油中生物柴油的掺混比增加,噪声的声功率级减小;从频谱上看,在不同的大气压力和燃用不同燃油时,各测试点的频谱曲线变化规律一致;该发动机测试点8的噪声声压级较其它测试点大,最大值达到103.1dB(A)。

This article studies the noise level of 4100QB-2 diesel engine under different altitudes using atmosphere simulation test when fueled with the different biodiesel /diesel blended fuel,and has carried on the frequency spectrum characteristic analysis.The result indicates that when use same fuel,the noise acoustical power rate level increases along with load and speed increasing,and decreases as the atmospheric pressure increases;Under the same operating mode,the noise acoustical power rate level reduces along with increasing biodiesel percent;for the frequency spectrum,under different atmospheric pressures and with different fuels,the variation law of different test points of the spectral curve is the same.The 8th point has the highest level with a maximum value of 103.1dB（A）.