Supercritical CO2 (SCO2) centrifugal compressors are pivotal components in next-generation high-efficiency power cycles (e.g., Brayton cycles), enabling greater than 50% thermal efficiency and compact power block designs essential for sustainable energy systems. This study addresses a critical reliability challenge by optimizing dry gas seal (DGS) groove designs for these compressors. Using validated 3D CFD simulations, incorporating k-ω SST turbulence model and Redlich-Kwong real gas equation of state, the performance of four industrial groove geometries (spiral, oval, fish-tail, and tree-type) are evaluated. Results demonstrate that the tree groove minimizes leakage (29.7% reduction vs. spiral) through tortuous flow paths, directly supporting emissions control and operational economy in power cycles. Conversely, spiral grooves maximize opening force and gas film stiffness (6.2% higher stiffness vs. tree), ensuring stable non-contact operation crucial for compressor reliability at extreme pressures. Oval and fish-tail grooves offer intermediate trade-offs. Thermal analysis reveals considerable localized high temperature zones due to viscous dissipation and adiabatic compression, a key consideration for material longevity. This work establishes that groove selection fundamentally balances leakage rate (optimized by tree grooves) against hydrodynamic stability (maximized by spiral grooves). These findings provide practical guidelines for enhancing DGS performance in SCO2 compressors, directly contributing to the viability of high-efficiency, low-emission power generation.
LiRXuCDaiT, et al.Thermodynamic analysis and optimization of a novel semi-closed supercritical CO2 power cycle integrated with an air separation unit incorporating LNG cold energy utilization. Energy2025; 332: 137183. https://doi.org/10.1016/j.energy.2025.137183
2.
CaoRLiZDengQ, et al.Effect of the hub cavity leakage on the aerodynamic performance and strength characteristics of the 150 kW SCO2 centrifugal compressor. Proc Inst Mech Eng Part A J. Power Energy2022; 236: 1472–1488. https://doi.org/10.1177/09576509221098867
3.
HeZYangJLiA, et al.Life cycle greenhouse gas emission assessment of solar power tower plant based on supercritical CO2 cycle operating at peak-shaving scenarios. Energy2025; 332: 137151. https://doi.org/10.1016/j.energy.2025.137151
SuomilammiAOyG. Vent gas collection from gas compressor dry gas seals. In: Proc. ASME Turbo Expo, 2004, Vienna, Austria, June 14-17, 2004, pp. 777–782. https://doi.org/10.1115/gt2004-53154
6.
LeongCGoyalS. Process-design considerations for a compressor dry-gas seal-system interface. Oil Gas Facil2015; 4: 72–76. https://doi.org/10.2118/178912-pa
7.
DayMAllisonT. Analysis of historical dry gas seal failure data. In: Proc. ASME Turbo Expo, 2016, Seoul, South Korea, June 13–17, 2016, pp. 1–10. https://doi.org/10.1115/GT2016-57076
RuanB. Finite element analysis of the spiral groove gas face seal at the slow speed and the low pressure conditions — slip flow consideration. Tribol Trans2000; 43: 411–418. https://doi.org/10.1080/10402000008982357
HeshunWCichangC. Numerical simulation on the geometric parameters of spiral grooved dry gas seals. In: 2009 ISECS Int. Colloq. Comput. Commun. Control. Manag. IEEE, 2009, pp. 5–8. https://doi.org/10.1109/CCCM.2009.5268008
13.
HeshunWWeibingZQiangW, et al.Numerical simulation on flow field of spiral grooved dry gas seals. 2010 int. Conf. Comput. Des. Appl. IEEE, 2010, pp. 227–230. https://doi.org/10.1109/ICCDA.2010.5541299
14.
WangBZhangH. Numerical analysis of a spiral-groove dry-gas seal considering micro-scale effects. Chinese J. Mech. Eng. English Ed2011; 24: 146–153. https://doi.org/10.3901/CJME.2011.01.146
15.
JingXXudongPShaoxianB, et al.CFD simulation of microscale flow field in spiral groove dry gas seal. In: Proc. 2012 IEEE/ASME 8th IEEE/ASME Int. Conf. Mechatron. Embed. Syst. Appl., 2012, pp. 211–217. https://doi.org/10.1109/MESA.2012.6275564
16.
HongWBaoshanZJianshuL, et al.A thermohydrodynamic analysis of dry gas seals for high-temperature gas-cooled reactor. J Tribol2012; 135: 021701. https://doi.org/10.1115/1.4007807
DingXLuJ. Theoretical analysis and experiment on gas film temperature in a spiral groove dry gas seal under high speed and pressure. Int J Heat Mass Tran2016; 96: 438–450. https://doi.org/10.1016/j.ijheatmasstransfer.2016.01.045
19.
SuHRahmaniRRahnejatH. Performance evaluation of bidirectional dry gas seals with special groove geometry. Tribol Trans2017; 60: 58–69. https://doi.org/10.1080/10402004.2016.1146380
20.
YanWJianjunSQiongH, et al.Orientation effect of orderly roughness microstructure on spiral groove dry gas seal. Tribol Int2018; 126: 97–105. https://doi.org/10.1016/j.triboint.2018.05.009
21.
FairuzZMJahnIAbdul-RahmanR. The effect of convection area on the deformation of dry gas seal operating with supercritical CO2. Tribol Int2019; 137: 349–365. https://doi.org/10.1016/j.triboint.2019.04.043
22.
YanWQiongHJianjunS, et al.Numerical analysis of T-groove dry gas seal with orientation texture at the groove bottom. Adv Mech Eng2019; 11: 1687814018821775. https://doi.org/10.1177/1687814018821775
23.
LiSQianCZhaoJ, et al.Dry gas seal performance analysis using a hydrodynamic and hydrostatic pressure decoupling method: part 1, seal. Tech2020; 2020: 4–9. https://doi.org/10.1016/S1350-4789(20)30291-9
24.
KouGLiXWangY, et al.Steady performance and dynamic characteristics of a superellipse groove dry gas seal at a high-speed condition. Ind Lubric Tribol2020; 72: 789–796. https://doi.org/10.1108/ILT-05-2019-0171
25.
YanRChenHZhangW, et al.Calculation and verification of flow field in supercritical carbon dioxide dry gas seal based on turbulent adiabatic flow model. Tribol Int2022; 165: 107275. https://doi.org/10.1016/j.triboint.2021.107275
26.
ChenYPengXJiangJ, et al.Experimental and theoretical studies of the dynamic behavior of a spiral-groove dry gas seal at high-speeds. Tribol Int2018; 125: 17–26. https://doi.org/10.1016/j.triboint.2018.04.005
27.
ChenYZhuoZLiY, et al.Prediction of spiral groove dry gas seal performance and intelligent optimization of structural parameters. Tribol Int2024; 193: 109439. https://doi.org/10.1016/j.triboint.2024.109439
28.
LuQJiangJMengX, et al.Effect of the 3D layered flow channels within the rotating ring on the steady-state performance of dry gas seals. Tribol Int2025; 208: 110651. https://doi.org/10.1016/j.triboint.2025.110651
29.
ZhangCJiangJPengX, et al.The influence and a direct judgement method of the flow state in supercritical CO2 dry gas seal. J. Brazilian Soc. Mech. Sci. Eng2021; 43: 486. https://doi.org/10.1007/s40430-021-03211-1
30.
ZhangLDingXWangS, et al.Research progress on the dynamic stability of dry gas seals. Processes2024; 12: 575. https://doi.org/10.3390/pr12030575
31.
GabrielRP. Fundamentals of spiral groove noncontacting face seals. Lubr Eng1994; 5: 215–224.
32.
BrunetièreN. A modified turbulence model for low reynolds numbers: application to hydrostatic seals. J Tribol2005; 127: 130–140. https://doi.org/10.1115/1.1829721
33.
CaiRYangMZhugeW, et al.Influence of real gas properties on aerodynamic stability of a SCO2 centrifugal compressor. Proc Inst Mech Eng Part A J. Power Energy2024; 238: 969–984. https://doi.org/10.1177/09576509241248885
AnbarsoozMNiazmandH. Heat transfer characteristics of slip flow over solid spheres. Proc Inst Mech Eng Part C J. Mech. Eng. Sci2016; 230: 3431–3441. https://doi.org/10.1177/0954406215612829
36.
NiazmandHAnbarsoozM. Slip flow over micron-sized spherical particles at intermediate reynolds numbers. J Mech Sci Technol2012; 26: 2741–2749. https://doi.org/10.1007/s12206-012-0723-x
