亚临界和超临界压力下液态正癸烷比定压热容实验研究

为了准确测量液态正癸烷的比定压热容，采用流动型绝热量热法,搭建了一套适用于亚临界和超临界压力下的流体比定压热容测量系统。对温度为311~570 K、压力为0.12~6.02 MPa的正癸烷比定压热容进行测量，结果表明比定压热容随温度的升高而增加，但压力对正癸烷的比定压热容影响较小，并将实验值与文献值进行对比，结果表明两者的最大相对偏差在5.0%以内，平均相对偏差在1.39%以内。将实验值与Guseinov模型和Garg模型两种经验模型进行对比，并在两种经验模型的基础上，提出改进后的比定压热容模型。改进后的模型精度较高，其最大绝对偏差为1.32%，平均相对偏差为0.53%,可为其他碳氢燃料的比定压热容的推算提供基础和参考依据。

Experimental study on isobaric specific heat capacity of liquid n-decane at subcritical and supercritical pressures

In order to accurately measure the isobaric specific heat capacity of liquid n-decane, a flow adiabatic calorimeter was constructed for subcritical pressure and supercritical pressure. The isobaric specific heat capacity of n-decane was measured at temperatures ranging from 311 K to 570 K and pressures ranging from 0.12 MPa to 6.02 MPa. The results show that the isobaric specific heat capacity of n-decane increases as the temperatures rise. And the system pressures have little effects on the isobaric specific heat capacity of n-decane. The experimental results were compared with the reference data. The results show that the maximum absolute deviation (MAD) is within 5.0%, and the average absolute deviation (AAD) is below 1.39%. Meanwhile, the experimental results were compared with Guseinov and Garg models. Based on the two empirical models, the improved isobaric specific heat capacity model was proposed. The improved model has higher fitting accuracy, showing that the MAD is 1.32%, and the AAD is 0.53%, which provides a basis and reference for the calculation of isobaric specific heat capacity of other hydrocarbon fuels.