天然气膨胀制冷工艺仿真优化

Simulation and optimization of natural gas expansion refrigeration process

基于Benedict-Webb-Rubin-Starling状态方程,建立等熵膨胀制冷模型。由于计算参数较多,涉及的多次迭代过程较复杂,在建立模型的过程中需设计多个子程序。其中较为特殊的是天然气混合物密度、压缩因子、气化率等的计算程序。针对各个子程序计算中存在的问题进行算法优化,解决了运算中的程序卡死、多解和运算效率低等问题;简化了运行步骤,提高了计算速度,使膨胀制冷模型准确高效地运行。实验结果表明,数据相对误差均小于0.02,计算结果真实可靠,可用于天然气等熵膨胀制冷计算,可为轻烃回收系统流程仿真模拟和优化奠定基础。

Based on Benedict-Webb-Rubin-Starling state equation,an isentropic expansion refrigeration model is established.Due to the large number of calculation parameters and the complex multi-iteration process involved,many subroutines are designed in the process of modeling.Among them,the special one is the calculation program of density,compression factor and vaporization rate of natural gas mixture.The algorithm is optimized to solve the problems existing in each subroutine calculation,such as program dead,multi-solution and low efficiency.At the same time,it can simplify the operation steps,improve the calculation speed and make the expansion refrigeration model run accurately and efficiently.The results show that the relative errors are all less than 0.02,the calculation results are true and reliable,which can be used to calculate the isentropic expansion refrigeration of natural gas,and can lay a foundation for simulation and optimization of the process of light hydrocarbon recovery system.