油罐车的非稳定传热计算

油罐车冬季卸油困难的主要原因是行程远，罐体散热快，致使原油温度低于凝点。通过建立油罐车稳定传热学模型，分析传热过程，得到罐内油品温度时间变化的计算公式。以“斯太尔”车原油制度为例，计算出温度与时间的对应值，并绘制出了温度与时间的变化曲线。

The Calculation on Non-Stable Heat Transfer for Road Tanker

The major cause which exists a troublesome problem in unloading the road tanker in winter is the long travel and fast heat transfer of tank,which makes the temperature of crude oil loaded decreased below the condensation point. The equations that the oil temperature whthin the tanker is changed with time are derived by means of establishing the model for non-stable heat transfer and analyzing the process of heat transfer. Taking the tank of Steyr road tanker as an example,the corresponding values of temperature versus time and the curve of temperature versus time are obtained. By comparing the calculated values with measured values,the maximum relative error is only 3. 5% ,which shows that the equations and the calculation method are practical and suitable for the design.