Systematic extension of a force field for fluorinated propenes to HCFO and longer-chained HFO compounds, and its application for studies on new working fluids

该项目的目的是系统地将氟化丙烯的力场扩展到基于氟化丁烯的氢氯氟烯烃(HCFO)和氢氟烯烃(HFO)。因此，它侧重于研究氟和氯原子的Lennard-Jones(LJ)参数的可转移性，以得出一组一致的LJ参数，从而能够研究具有任意数量的成键卤素原子的不同HFO/HCFO化合物。此外，氟化丁烯中的二面体的旋转导致了复杂的扭转轮廓。这需要对可能的函数形式进行详细分析，以再现扭矩分布，以及它对液体粘度模拟研究的影响。这项分析还必须考虑到扭转参数的可转移性。这些研究将基于不同的HCFO化合物和氟化丁烯进行，这些化合物和氟丁烯目前被建议作为各种应用的新工作介质。然后将扩展力场用于分子模拟研究纯化合物和不同二元混合物的汽液相平衡以及液体密度和粘度。分子模拟结果将被合作伙伴用于开发这些体系的状态方程(EOS)模型。然后，EOS模型将被用于对选定的二元混合物的热系统的系统模拟研究，以说明使用来自分子模拟的信息来评估新的工作流体。

The aim of this project is the systematic extension of a force field for fluorinated propenes to hydrochlorofluoroolefines (HCFO) and hydrofluoroolefines (HFO) based on fluorinated butenes. It thereby emphasis on investigating the transferability of the Lennard-Jones (LJ) parameters for fluorine and chlorine atoms to derive a consistent set of LJ parameters that enables studies on different HFO/HCFO compounds with any number of bonded halogen atoms. Furthermore, the rotations about dihedrals in fluorinated butenes result in complex torsion profiles. This requires a detailed analysis on possible functional forms to reproduce the torsion profiles, and its influence on simulation studies on liquid viscosities. This analysis has also to be performed with regard to the transferability of the torsion parameters.The studies will be carried out on the basis of different HCFO compounds and fluorinated butenes that are currently proposed as new working fluids for various applications. The extended force field will then be employed for molecular simulation studies on the vapor-liquid phase equilibria and liquid phase densities and viscosities of the pure compounds and different binary mixtures. The molecular simulation results will be used by cooperation partner to develop equation of state (EOS) models for these systems. The EOS models will then be employed in system simulation studies on thermal systems for selected binary mixtures to illustrate the use of information from molecular simulations to evaluate new working fluids.