Effects of the real-gas characteristics of carbon dioxide with impurities on the dry gas seal performance

doi:10.11949/0438-1157.20191556

Abstract

Abstract:

Based on the EOS-CG model and GERG-2008 model, the density of the mixed carbon dioxide gas containing impurities is calculated, and the viscosity of the mixed gas is calculated based on the CO₂-Pedersen model. The relationship between density, viscosity and pressure of pure carbon dioxide and mixed gas are obtained by fitting the calculated data of these models to describe the real gas behavior and the law of viscosity changing with pressure of pure carbon dioxide and mixed gas. The steady-state Reynolds equation is solved by using the finite difference method, and the opening force, leakage rate and film stiffness of the dry gas seal lubricated by pure carbon dioxide or carbon dioxide with impurities are obtained, and the influence of impurities on the performance (opening force, leakage rate, film stiffness) is also analyzed. The variables considered include the average linear velocity of the end face, film thickness, inlet temperature, and inlet pressure. The results show that when inlet pressure is 15.26 MPa, and inlet temperature is 363.15 K, and linear velocity of the end face is 74.030 m/s, and film thickness is 3.05 μm, both the opening force and leakage rate of the dry gas seal lubricated by carbon dioxide with impurities are lower than those of pure carbon dioxide dry gas seal. The more impurities content, the more obvious the difference. The effect of impurities on the opening force, leakage rate, and film stiffness of the carbon dioxide dry gas seal increases with the increasing of the averaged linear velocity of the end face. The effect on the leakage rate and film stiffness decreases with the increasing of the film thickness. The effect on the opening force, leakage rate, and film stiffness decreases with the increasing inlet temperature. The influence on the opening force of carbon dioxide dry gas seal decreases firstly, then increases, and finally decreases with the increasing of the inlet pressure, and the influence on the leakage rate of carbon dioxide dry gas seal increases firstly and then decreases with the increasing of the inlet pressure, and the influence on the film stiffness decreases firstly and then increases with the increasing of the inlet pressure.

Key words: impurity, carbon dioxide, real gas, dry gas seal, viscosity, numerical analysis

摘要：

基于EOS-CG模型和GERG-2008模型计算含杂质二氧化碳混合气体的密度，基于CO₂-Pedersen模型计算混合气体的黏度。利用模型计算数据拟合获得含杂质二氧化碳混合气体密度、黏度与压力的关系式，用以描述混合气体的实际行为以及黏度随压力变化的规律。采用有限差分法求解稳态雷诺方程，得到了纯二氧化碳和含杂质二氧化碳干气密封开启力、泄漏率以及气膜刚度，并分析了杂质对二氧化碳干气密封性能(开启力、泄漏率、气膜刚度)的影响。考虑的变量有端面平均线速度、气膜厚度、进口温度以及进口压力等。结果表明：当进口压力为15.26 MPa，进口温度为363.15 K，线速度为74.030 m/s，气膜厚度为3.05 μm时，含杂质二氧化碳干气密封开启力和泄漏率都小于纯二氧化碳干气密封开启力和泄漏率，且杂质含量越多，差别越明显；杂质对二氧化碳干气密封开启力、泄漏率、气膜刚度的影响随端面平均线速度的增大而增大；对泄漏率、气膜刚度的影响随气膜厚度的增加而减小；对开启力、泄漏率、气膜刚度的影响随进口温度的增大而减小；对开启力的影响随进口压力的增大先减小，再增大，最后减小，对泄漏率的影响随进口压力的增大先增大后减小，对气膜刚度的影响随进口压力的增大先减小后增大。

关键词: 杂质, 二氧化碳, 实际气体, 干气密封, 黏度, 数值分析

CLC Number:

TH 117

Wei CHEN, Pengyun SONG, Hengjie XU, Xuejian SUN. Effects of the real-gas characteristics of carbon dioxide with impurities on the dry gas seal performance[J]. CIESC Journal, 2020, 71(5): 2215-2229.

陈维, 宋鹏云, 许恒杰, 孙雪剑. 含杂质二氧化碳实际气体干气密封性能研究[J]. 化工学报, 2020, 71(5): 2215-2229.

Figures/Tables 21

References 33

1	郑荣伟, 冯晓娟, 伍肆, 等. 近临界区二氧化碳声速的精密测量研究[J]. 计量学报, 2017, 38(1): 1-6.
	Zheng R W, Feng X J, Wu S, et al. Sound speed measurement for carbon dioxide near the critical region [J]. Acta Metrologica Sinica, 2017, 38(1): 1-6.
2	康丽娜, 尚会建, 郑学明. CO₂的捕集封存技术进展及在我国的应用前景[J]. 化工进展, 2010, 29: 24-27.
	Kang L N, Shang H J, Zheng X M. Progress of CO₂capture and storage and its application prospects in China[J]. Chem. Ind. & Eng. Prog., 2010, 29: 24-27.
3	刘嘉, 李永, 刘德顺. 碳封存技术的现状及在中国应用的研究意义[J]. 环境与可持续发展, 2009, (2): 33-35.
	Liu J, Li Y, Liu D S. Status of technology on carbon capture and storage and significance of research on its application in China[J]. Environment and Sustainable Development, 2009, (2): 33-35.
4	张振冬, 杨正先, 张永华, 等. CO₂捕集与封存研究进展及其在我国的发展前景[J]. 海洋环境科学, 2012, 31(3): 456-459.
	Zhang Z D, Yang Z X, Zhang Y H, et al. Study progress on CO₂ capture and storage and development prospect in China[J]. Marine Environmental Science, 2012, 31(3): 456-459.
5	张卫东, 张栋, 田克忠．碳捕集与封存技术的现状与未来[J]. 中外能源, 2009, 14(11): 7-14.
	Zhang W D, Zhang D, Tian K Z. Carbon capture and sequestration technology[J]. Sino-Global Energy, 2009, 14(11): 7-14.
6	Forbes S M, Verma P, Curry T E, et al. Guidelines for Carbon Dioxide Capture, Transport and Storage[M]. World Resources Institute, 2008.
7	王宝群, 李会泉, 包炜军. 燃煤电厂CO₂捕集与咸水层封存全过程经济性模型[J]. 化工学报, 2012, 63(3): 894-903.
	Wang B Q, Li H Q, Bao W J. A model of economy for overall process of CO₂ capture and saline storage[J]. CIESC Journal, 2012, 63(3): 894-903.
8	翟明洋, 林千果, 马丽, 等. 电力行业碳捕集现状和发展趋势[J]. 环境科技, 2014, 27(2): 65-69.
	Zhai M Y, Lin Q G, Ma L, et al. Current status and development of carbon capture in power generation industry[J]. Environmental Science and Technology, 2014, 27(2): 65-69.
9	Peletiri S P, Rahmanian N, Mujtaba I M. Effects of impurities on CO₂ pipeline performance[J]. Chem. Eng. Trans., 2017, 57: 355-360.
10	Li H, Jakobsen J P, Ø Wilhelmsen, et al. PVTxy properties of CO₂ mixtures relevant for CO₂capture, transport and storage: review of available experimental data and theoretical models[J]. Applied Energy, 2011, 88(11): 3567-3579.
11	Zhao Q, Li Y X. The influence of impurities on the transportation safety of an anthropogenic CO₂ pipeline[J]. Process Safety and Environmental Protection, 2014, 92(1): 80-92.
12	许恒杰, 宋鹏云, 毛文元, 等. 层流状态下高压高转速二氧化碳干气密封的惯性效应分析[J]. 化工学报, 2018, 69(10): 4311-4323.
	Xu H J, Song P Y, Mao W Y, et al. Analysis on inertia effect of carbon dioxide dry gas seal at high speed and pressure under laminar condition[J]. CIESC Journal, 2018, 69(10): 4311-4323.
13	沈伟, 彭旭东, 江锦波, 等. 高速超临界二氧化碳干气密封实际效应影响分析[J]. 化工学报, 2019, 70(7): 2645-2659.
	Shen W, Peng X D, Jiang J B, et al. Analysis on real effect of supercritical carbon dioxide dry gas seal at high speed[J]. CIESC Journal, 2019, 70(7): 2645-2659.
14	孙雪剑, 宋鹏云, 毛文元, 等. 考虑实际气体效应双列螺旋槽干气密封反转性能分析[J]. 工程科学与技术, 2019, 51(4): 1-9.
	Sun X J, Song P Y, Mao W Y, et al. Analysis on the performance of the reverse rotation of double spiral groove dry gas seal considered effect of real gas behavior[J]. Advanced Engineering Sciences, 2019, 51(4): 1-9.
15	Du Q W, Gao K K, Zhang D, et al. Effects of grooved ring rotation and working fluid on the performance of dry gas seal[J]. International Journal of Heat and Mass Transfer, 2018, 126: 1323-1332.
16	Zakariya M F, Jahn I H J. Performance of supercritical CO₂ dry gas seals near the critical point[C]//ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016.
17	Fairuz Z M, Jahn I. The influence of real gas effects on the performance of supercritical CO₂ dry gas seals[J]. Tribology International, 2016, 102: 333-347.
18	王珺瑶, 张月, 邓帅, 等. CO₂混合物热物性在CCS研究中的作用: 实验数据、理论模型和典型应用[J]. 化工进展, 2019, 38(3): 1244-1258.
	Wang J Y, Zhang Y, Deng S, et al. Role of thermodynamic properties of CO₂ mixtures in CCS: data, models and typical applications[J]. Chemical Industry and Engineering Progress, 2019, 38(3): 1244-1258.
19	宋鹏云, 胡晓鹏, 许恒杰. 实际气体对T槽干气密封动态特性的影响[J]. 化工学报, 2014, 65(4): 1344-1352.
	Song P Y, Hu X P, Xu H J. Effect of real gas on dynamic performance of T-groove dry gas seal [J].CIESC Journal, 2014, 65(4): 1344-1352.
20	Span R, Wagner W. A new equation of state for carbon dioxide covering the fluid region from the triple-point temperature to 1100K at pressures up to 800MPa[J]. J. Phys. Chem. Ref. Data, 1996, 25(6): 1509-1596.
21	Fenghour A, Wakeham W A, Vesovic V. The viscosity of carbon dioxide[J]. Journal of Physical and Chemical Reference Data, 1998, 27(1): 31-44.
22	Nazeri M, Chapoy A, Burgass R, et al. Viscosity of CO₂-rich mixtures from 243 K to 423 K at pressures up to 155MPa: new experimental viscosity data and modelling[J]. J. Chem. Thermodynamics, 2018, 118: 100-114.
23	IEA GHG. Oxy-combustion processes for CO₂capture from power plant[R]. IEA Greenhouse Gas R&D Programme, Cheltenham, GL52 7RZ, UK, 2005.
24	Gernert J, Span R. EOS-CG: a Helmholtz energy mixture model for humid gases and CCS mixtures [J]. J. Chem. Thermodynamics, 2016, 93: 274-293.
25	Kunz O, Wagner W. The GERG-2008 wide-range equation of state for natural gases and other mixtures: an expansion of GERG-2004[J]. J. Chem. Eng. Data, 2012, 57(11): 3032-3091.
26	Span R, Lemmon E W, Jacobsen R T, et al. A reference equation of state for the thermodynamic properties of nitrogen for temperatures from 63.151 to 1000 K and pressures to 2200 MPa[J]. Journal of Physical and Chemical Reference Data, 2000, 29(6): 1361-1433.
27	Schmidt R, Wagner W. A new form of the equation of state for pure substances and its application to oxygen[J]. Fluid Phase Equilibria, 1985, 19: 175-200.
28	Tegeler C, Span R, Wagner W. A new equation of state for argon covering the fluid region for temperatures from the melting line to 700 K at pressures up to 1000 MPa[J]. J. Phys. Chem. Ref. Data, 1999, 28(3): 779-850.
29	Lemmon E W, Span R. Short fundamental equations of state for 20 industrial fluids[J]. J. Chem. Eng. Data, 2006, 51: 785-850.
30	Chapoy A, Nazeri M, Kapateh M, et al. Effect of impurities on thermophysical properties and phase behaviour of a CO₂-rich system in CCS[J]. International Journal of Greenhouse Gas Control, 2013, 19(2): 92-100.
31	Rusin A. Advances in Carbon Dioxide Compression and Pipeline Transportation Processes[M]. Berlin: Springer International Publishing, 2015.
32	Gabriel R P. Fundamentals of spiral groove noncontacting face seals[J]. Lubrication Engineering, 1994, 50(3): 215-224.
33	宋鹏云. 螺旋槽干气密封端面气膜压力计算方法讨论[J]. 润滑与密封, 2009, 34(7): 7-9.
	Song P Y. Discussion about the calculation methods of the gas film pressure of the spiral groove dry gas seals[J]. Lubrication Engineering, 2009, 34(7): 7-9.

Case	CO₂	CH₄	N₂	O₂	Ar	CO	H₂
case 1^[22]	0.94923	0.006261	0.0141	0.008007	0.0121	0.002127	0.008175
case 2^[18]	0.85	0	0.058	0.0473	0.0447	0	0
case 3^[23]	0.7567	0	0.1563	0.0625	0.0245	0	0

Case	CO₂	CH₄	N₂	O₂	Ar	CO	H₂
case 1^[22]	0.94923	0.006261	0.0141	0.008007	0.0121	0.002127	0.008175
case 2^[18]	0.85	0	0.058	0.0473	0.0447	0	0
case 3^[23]	0.7567	0	0.1563	0.0625	0.0245	0	0

介质	a₁	a₂	a₃	a₄×10⁴	a₅×10⁴	a₆×10⁶	a₇×10⁷
CO₂	-0.03954	14.7126	0.25240	559.570	-68.1477	624.333	-196.379
case1	-0.00445	14.2896	0.31808	197.799	-15.2426	195.270	-76.3254
case2	0.00545	14.0039	0.29880	33.9825	5.17511	-9.69194	-10.3480
case3	0.00391	13.4536	0.24557	1.16314	5.29879	-34.0508	2.60187

介质	a₁	a₂	a₃	a₄×10⁴	a₅×10⁴	a₆×10⁶	a₇×10⁷
CO₂	-0.03954	14.7126	0.25240	559.570	-68.1477	624.333	-196.379
case1	-0.00445	14.2896	0.31808	197.799	-15.2426	195.270	-76.3254
case2	0.00545	14.0039	0.29880	33.9825	5.17511	-9.69194	-10.3480
case3	0.00391	13.4536	0.24557	1.16314	5.29879	-34.0508	2.60187

介质	b₁	b₂×10²	b₃×10³	b₄×10⁴	b₅×10⁶
CO₂	17.9820	9.71547	5.24826	17.3632	60.0045
case1	18.1875	7.81223	9.01788	14.5182	23.5871
case2	18.7157	6.68971	10.1825	12.0689	-5.21244
case3	18.9892	5.92823	10.6680	8.99668	-13.7208