混合物非平衡气液两相临界流动压力计算模型
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摘要
气液两相临界流动压力是气液两相输送系统中安全阀尺寸设计、孔口泄漏速率计算的关键参数,现有的临界流动压力计算方法主要是针对单组分流体建立的,对多组分混合物的适用性差。针对这一问题,基于现有的非平衡均相流动(HNE-DS)模型和适用于多组分混合物的Peng-Robinson状态方程,推导了新的非平衡压缩系数表达式;通过拟合实验数据,得到新的临界流动压力比和非平衡压缩系数关联式,建立了改进的HNE-DS模型。结果表明:对于单组分流体,改进HNE-DS模型计算的临界压力比与实验值之间的平均相对偏差为3.3%,较原模型减小了1.6%。对于多组分混合物,改进HNE-DS模型的计算值更接近实际情况。成果为准确计算多组分混合物的临界流动压力提供了依据。
The critical flow pressure is an essential parameter for sizing the safety valve design and computing leakage mass flow rate of vapor-liquid two-phase systems. The existing critical pressure calculation models are mainly developed for the single-component fluid, difficult to be applied to multi-component systems. In order to solve this problem, based on the Homogeneous Non-Equilibrium Diener-Schmidt(HNE-DS) model and Peng-Robinson equation of state designed for multi-component mixtures, a new non-equilibrium compression factor formula were proposed in this paper. Moreover, a new correlation that describes the relationship between the non-equilibrium compression factor and the critical flow pressure ration is built by fitting the experimental data, yielding an improved HNE-DS model. The results show that, for the single-component fluid and the improved HNE-DS model, the average relative error between the calculated critical pressure ratios and experimental data is 3.3%, which is reduced by 1.6% in comparison with the original HNE-DS model. For the multi-component mixtures, the results calculated forms are more likely to represent the actual values and provides an efficient way to accurately calculate the critical flow pressures for multi-component mixtures.
The critical flow pressure is an essential parameter for sizing the safety valve design and computing leakage mass flow rate of vapor-liquid two-phase systems. The existing critical pressure calculation models are mainly developed for the single-component fluid, difficult to be applied to multi-component systems. In order to solve this problem, based on the Homogeneous Non-Equilibrium Diener-Schmidt(HNE-DS) model and Peng-Robinson equation of state designed for multi-component mixtures, a new non-equilibrium compression factor formula were proposed in this paper. Moreover, a new correlation that describes the relationship between the non-equilibrium compression factor and the critical flow pressure ration is built by fitting the experimental data, yielding an improved HNE-DS model. The results show that, for the single-component fluid and the improved HNE-DS model, the average relative error between the calculated critical pressure ratios and experimental data is 3.3%, which is reduced by 1.6% in comparison with the original HNE-DS model. For the multi-component mixtures, the results calculated forms are more likely to represent the actual values and provides an efficient way to accurately calculate the critical flow pressures for multi-component mixtures.
引文
[1] 周雪.LNG储罐区泄漏扩散分析及后果评价技术研究[D].成都:西南石油大学,2017.
[2] 叶学礼.天然气放空管路水力计算[J].天然气工业,1999,19(3):90-94.
[3] FALETTI D W,MOULTON R W.Two‐phase critical flow of steam‐water mixtures[J].AIChE Journal,1963,9(2):247-253.
[4] LEUNG J C.Easily size relief devices and piping for two-phase flow[J].Chemical Engineering Progress,1996,92(12):28-50.
[5] LEUNG J C.Generalized correlation for one-component homogeneous equilibrium flashing choked flow[J].AlChE J,1986,32(10):1743-1746.
[6] AMERICAN PETROLEUM INSTITUTE.API STD520-1 sizing,selection,and installation of pressure-relieving devices part I-Sizing and selection [S].Washington DC:API Publishing,2014.
[7] HENRY R E,FAUSKE H K.The two-phase critical flow of one-component mixtures in nozzles,orifices,and short tubes[J].Journal of Heat Transfer,1971,93(2):179-187.
[8] SCHMIDT,J.Sizing of nozzles,venturis,orifices,control and safety valves for initially sub-cooled gas/liquidtwo-phase flow-The HNE-DS method[J].ForschungimIngenieurwesen,2007,71(1):47-58.
[9] SCHMIDT J.CLARAMUNT S.Sizing of rupture disks for two-phase gas/liquid flow according to HNE-CSEmodel[J].J Loss Prev Process Ind,2016,41:419-432.
[10] ISO.ISO4126-10 safety devices for protection against excessive pressure-Part 10:Sizing of safety valves for gas/liquid two-phase flow[S].Berlin:DeutschesInstitutfurNormung,2010.
[11] WU Xia,LI Changjun,HE Yufa,et al.Dynamic modeling of the two-phase leakage process of natural gas liquid storage tanks[J].Energies,2017,10(9):1399.
[12] GROLMES M A,LEUNG J C.Multi-phase flow and heat transfer Ⅲ,A:Fundamentals [M].Amsterdam:Elsevier,1984.
[13] CHIEN S F.Critical flow of wet steam through chokes[J].Journal of Petroleum Technology,1990,42(3):363-370.
[2] 叶学礼.天然气放空管路水力计算[J].天然气工业,1999,19(3):90-94.
[3] FALETTI D W,MOULTON R W.Two‐phase critical flow of steam‐water mixtures[J].AIChE Journal,1963,9(2):247-253.
[4] LEUNG J C.Easily size relief devices and piping for two-phase flow[J].Chemical Engineering Progress,1996,92(12):28-50.
[5] LEUNG J C.Generalized correlation for one-component homogeneous equilibrium flashing choked flow[J].AlChE J,1986,32(10):1743-1746.
[6] AMERICAN PETROLEUM INSTITUTE.API STD520-1 sizing,selection,and installation of pressure-relieving devices part I-Sizing and selection [S].Washington DC:API Publishing,2014.
[7] HENRY R E,FAUSKE H K.The two-phase critical flow of one-component mixtures in nozzles,orifices,and short tubes[J].Journal of Heat Transfer,1971,93(2):179-187.
[8] SCHMIDT,J.Sizing of nozzles,venturis,orifices,control and safety valves for initially sub-cooled gas/liquidtwo-phase flow-The HNE-DS method[J].ForschungimIngenieurwesen,2007,71(1):47-58.
[9] SCHMIDT J.CLARAMUNT S.Sizing of rupture disks for two-phase gas/liquid flow according to HNE-CSEmodel[J].J Loss Prev Process Ind,2016,41:419-432.
[10] ISO.ISO4126-10 safety devices for protection against excessive pressure-Part 10:Sizing of safety valves for gas/liquid two-phase flow[S].Berlin:DeutschesInstitutfurNormung,2010.
[11] WU Xia,LI Changjun,HE Yufa,et al.Dynamic modeling of the two-phase leakage process of natural gas liquid storage tanks[J].Energies,2017,10(9):1399.
[12] GROLMES M A,LEUNG J C.Multi-phase flow and heat transfer Ⅲ,A:Fundamentals [M].Amsterdam:Elsevier,1984.
[13] CHIEN S F.Critical flow of wet steam through chokes[J].Journal of Petroleum Technology,1990,42(3):363-370.