超临界汽油燃料及其替代混合物的物性

Thermophysical Properties of Gasoline and Surrogates Under Supercritical Conditions

汽油机超临界/跨临界喷射燃烧的研究离不开可靠的燃油物理性质,在较大温度范围内评估了12种汽油替代混合物在预测汽油的临界温度、临界压力、密度、动力黏度和定压比热方面的能力.采用8种关联式估算出汽油的临界温度和临界压力,平均值分别为550.4,K和3.092,MPa.替代混合物临界温度估算值为538.9,K(Sur,4)到586,K(Sur,5)之间,临界压力估算值在2.57,MPa(Sur,1)到3.244,MPa(Sur,10)之间,其中Sur,8的临界参数与汽油最接近.通过美国国家标准与技术研究院开发的物性计算软件SUPERTRAPP计算汽油替代混合物的密度、动力黏度和定压比热值并与测试结果对比,结果显示:预测密度、比热和黏度准确性最高的分别是Sur,8(平均绝对偏差A_(AAD)为7.292%,)、Sur,2(A_(AAD)为8.929%,)和Sur,10(A_(AAD)为10.976%,),综合平均绝对偏差最小的为Sur,4(13.149%,).

Research on the surpercritical and transcritical combustion of gasoline engine requires reliable data on gasoline properties.Twelve gasoline surrogates for predicting gasoline properties under a wild temperature range,including critical temperature,critical pressure,density,heat capacity and viscosity were evaluated.The estimated average critical temperature and pressure of gasoline are 550.4,K and 3.092,MPa respectively,while those of surrogates varies from 538,K（Sur,4）to 586,K（Sur,5）and 2.57,MPa（Sur,1）to 3.244,MPa（Sur,10）.More reliable prediction of density, heat capacity and viscosity of gasoline were achieved by Sur,8（A_（AAD）=7.292%）,Sur,2（A_（AAD）=8.929%）and Sur,10（A_（AAD）=10.976%）,respectively.Sur,4 was the most reliable surrogate on predicting the three parameters with an A_（AAD）=13.149%,.