Experimental Demonstration of a Novel Supercritical CO2 Seal Concept on a 2′′ Static Test Rig
Document Type
Conference Proceeding
Publication Date
2-2024
Publication Title
The 8th International Supercritical CO2 Power Cycles Symposium
Abstract
Supercritical carbon dioxide (sCO2) power cycles outperform conventional water-based/ airbreathing, direct-fired, open Brayton cycles or indirect-fired, closed Rankine cycles as far as the efficiency and equipment footprint are concerned. sCO2 power cycles have promising potential to be used in concentrated solar power, fossil fuel power plants, geothermal electricity, nuclear power, and ship propulsion. Technology readiness must be proven on a scale of 10 – 600 MWe and at temperatures and pressures of 350–700°C and 20 – 35 MPa for nuclear industries, respectively, to realize the full potential of sCO2 power cycles. One of the critical issues at the component level is the lack of effective shaft seals at sCO2 operation conditions. While conventional seals are currently limited in some way by their inability to handle such high pressure and temperature, only a few non-conventional ones can survive sCO2 conditions. To offer a potential solution, we propose an elastohydrodynamic (EHD) scalable high-temperature, high-pressure shaft end seal that leverages the proven elastohydrodynamic lubrication theory. The distinctive mechanism of such an EHD seal provides a self-regulated constriction effect to restrict the flow without significant material contact, thereby minimizing leakage and wear. One of the prominent features of the EHD seal is that it provides tighter sealing at increased pressures, sustaining a continuous fluid film between itself and the rotor. In this study, the working mechanism of the EHD seal was proven experimentally on a 2-in static rotor test rig. Tests were carried out using nitrogen as the working fluid at the room temperature to avoid complexity. The test seal was made of PEEK which had an elastic modulus of 3.65 GPa and a tensile strength of 96.53 MPa. The static shaft was made of stainless steel with a diameter of 2 in. The trials were run with a maximum inlet pressure of 15 MPa and an initial clearance of 41 µm. The throttling effect of the EHD seal was clearly demonstrated in these early trials. These preliminary findings suggest that the proposed EHD seal design can potentially be applied to sCO2 turbomachinery.
Recommended Citation
Hassan, Mohammad Fuad, Hanping Xu, Mohammad Towhidul Islam, Sevki Cesmeci, Shuangbiao Liu, Aaron Harcrow, Ali Akbor Topu, Md Wasif Hasan, Jonah Henry, Joshua Bunting, David Dewis, Jing Tang.
2024.
"Experimental Demonstration of a Novel Supercritical CO2 Seal Concept on a 2′′ Static Test Rig."
The 8th International Supercritical CO2 Power Cycles Symposium: 1-22.
https://digitalcommons.georgiasouthern.edu/mech-eng-facpubs/238
Comments
Georgia Southern University faculty member, Sevki Cesmeci co-authored Experimental Demonstration of a Novel Supercritical CO2 Seal Concept on a 2′′ Static Test Rig.