低温溢油异常蒸发行为的数学模型与模拟

The mathematical modeling and simulation on abnormal evaporation of spilled oil at low temperature

摘要:

为了考察低温环境下溢油蒸发行为,通过浅盘蒸发试验测定了0#柴油和大庆原油在温度分别处于各自凝点附近的"低温"环境下的蒸发量,结合混合液蒸发机理,引入衰减因子e-k/Δθ,建立低温溢油蒸发模型.研究表明:当环境与溢油凝点温差(Δθ)小于10℃时需采用改进模型预测蒸发过程,此时,油膜液相阻力增大,一定深度内(h)的挥发组分被蒸发掉,且h随Δθ减小而降低,柴油与大庆原油的液相阻力增加系数k分别为0.993和0.989.有冰水面溢油的蒸发过程受暴露于大气中的油膜面积(Af)与厚度(ho)影响较大,应采用(Afhoe-k/Δθ)/V为衰减系数的模型对其进行预测.改进后的模型可较好的预测低温条件下油品的蒸发过程.

Abstract:

In order to predict the evaporative amount of spilled oil at low temperature,the shallow dish test was conducted to investigate the evaporation of diesel and Daqing crude oil,respectively. On the basis of the mixed liquid evaporation mechanism,Fingas’evaporation models were ameliorated by adding a coefficient e-k/θ. The experimental results indicate that the ameliorated models are adopted when the difference between air temperature and the oil’s solidifying point (θ) is less than 10 ℃. The volatile components come into the air from the oil surface within a certain depth(h),which decreases as T decreases. The resistance coefficient k is 0. 993 and 0. 989 for the diesel and crude oil,respectively. The evaporation of oil on the water surface infested with ice is closely related to the exposed area (Af) and thickness (ho) of the oil slick,which can be simulated by the model appended with (Afhoe-k/θ) /V. The ameliorated models can simulate the oil evaporation very well at low temperature.