关键词: 正癸烷；裂解；广义对应态法则；物性；快速计算

Abstract: In order to study the calculation methods in the mild cracking of decane，three calculation methods of density，viscosity，thermal conductivity and specific heat at constant pressure in the cracking of decane by extended corresponding state law were conducted，including direct computation，interpolation computation by physical properties library and mixing computation by physical properties sublibrary. On the basis of the accuracy of direct computation，via contrasting computation accuracy，computation memory and computation time with each other，the performances of three methods were assessed comprehensively，and the effects of the cracking degree on the physical properties at high temperature were investigated. In the computation，the temperature，pressure and cracking degree ranged from 300K to 1020K，from 1MPa to 15MPa，from 0 to 0.25，respectively. The results indicate that all computation methods could qualitatively reproduce fancy variation of physical property. Relative to the direct computation，interpolation computation by physical properties library could obtain improved computation accuracy and that the error received by mixing computation by physical properties sublibrary is proportional with the cracking degree. Provided that the computation memory，interpolation computation by physical properties library could accelerate computation without precision loss. Under mildly cracking it is advisable to use mixing computation by physical properties sublibrary for fast engineering calculation. The significant influence on the physical properties at high temperature by the cracking degree could not be neglected.

Key words: Decane；Cracking；Extended-corresponding-state law；Physical property；Fast calculation