隐式拟合在天然气热力性质计算中的应用

天然气物性计算的精度、速度和稳定性对天然气流程数值模拟效果影响很大。基于此，提出了天然气热力性质的隐式拟合模型，并给出了将该模型转化为显式计算的方法。该方法能够保证天然气热力性质计算的可逆性，同时由于不存在迭代，因而保证了热力性质计算的绝对稳定性。以国内某LNG接收站天然气组分为例，以HYSYS计算结果作为数据源，对上述模型进行验证。结果表明：该模型在拟合范围内最大计算偏差小于1％，且计算速度远快于LKP状态方程。该方法因模拟结果精确、计算效率高，在天然气工业领域的流程模拟中，具有较好的推广应用前景。（表6，参11）

Application of implicit curve-fitting in the calculation of thermodynamic property of natural gas

The precision, velocity and stability for the calculation of property of natural gas have great impact on the numerical simulation of natural gas process. Therefore, the paper puts forward the implicit curve-fitting model of the thermodynamic property of natural gas, and gives the method of transforming from this model into explicit calculation. This method can ensure the reversibility of the calculation of thermodynamic property of natural gas, and meanwhile, because there is no iteration, it also ensures the absolute stability of the calculation of thermodynamic property. Taking the natural gas component of a domestic LNG terminal as an example, and the HYSYS calculation result as the data source, the model above is verified. The results show that the maximum relative deviation of this model in the fitting range is less than 1%, and the calculation speed is much faster than the LKP state equation. Since this method is accurate and highly efficient in simulation, it has a good prospect of widespread application in the process simulation of natural gas industry. （6 Tables, 11 References）