Numerical and Experimental Analysis of an Elastohydrdynamic Seal For Gases
Location
Poster Session 1 (Henderson Library)
Session Format
Poster Presentation
Your Campus
Statesboro Campus- Henderson Library, April 20th
Academic Unit
Department of Mechanical Engineering
Research Area Topic:
Engineering and Material Sciences - Mechanical
Co-Presenters and Faculty Mentors or Advisors
1st Co Presenter: Jonah Henry
2nd Co Presenter: Joshua Bunting
Faculty Advisor: Sevki Cesmeci, PhD
Abstract
Supercritical CO2 (sCO2) power cycles are superior to traditional water-based, air-breathing, direct-fired, open Brayton cycles; or indirect-fired, closed Rankine cycles in terms of efficiency and equipment footprint. They hold great potential in nuclear power production, fossil fuel power plants, concentrated solar power, geothermal power, and ship propulsion. To unlock the potential of sCO2 power cycles, technology readiness must be demonstrated on the scale of 10 – 600 MWe and at the sCO2 temperatures and pressures of 350 – 700 ºC and 20 – 35 MPa for nuclear industries. The lack of suitable shaft seals at sCO2 operating conditions is one of the main challenges at the component level. So far, conventional seals are all incapable of handling sCO2 pressure and temperature in one way or another. In this study, we propose a novel Elasto-Hydrodynamic (EHD) high-pressure, high temperature, and scalable shaft seal for sCO2 turbomachinery that offers low leakage, minimal wear, low cost, and no stress concentration. The focus in this paper was to conduct a proof-of-concept study with the help of computer simulations. To this end, a fully coupled Fluid-Structure Interaction (FSI) modeling approach was adopted, and the simulations were carried out in COMSOL Multiphysics software. The modeling approached was presented thoroughly, the results were discussed, and the next research steps were highlighted. Under the EHD mechanism: the higher the pressures are, the tighter the sealing becomes, while still sustaining a continuous sCO2 film. For proof-of-concept purposes, a 2” diameter shaft static test rig was designed at Georgia Southern University before the actual dynamic testing at Sandia National Laboratories. For the sake of simplicity, the working fluid was chosen to be Nitrogen, and the tests were conducted at room temperature. The test rig consisted of a 16.5 MPA N2 tank, steel tubing with compression type fittings, an OMEGA – PX1009L0-5KSV pressure sensor to measure the pressure of the N2 after the pressure regulator from the tank, a chamber housing the 2” steel shaft and EHD seal (two prototype steel seals with seal clearances of 25 µm and 50 µm), a CONAX – K-INC12-U-T3(5FT)-7.5" temperature sensor to collect temperature data in the chamber, and an OMEGA – FMA-1601A mass flow meter with temperature and pressure measurement capability to evaluate conditions after the test chamber. The pressure, temperature, and mass flow rate data were collected via a National Instruments DAQ – Module NI-9205 and a LabVIEW program. The tests were conducted for an inlet pressure of 0.1 ~ 15 MPa and at two different clearances of 25 µm and 50 µm. The mass flow rate exhibited a quadratic trend with increased pressure, which proved the hypothesis.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Presentation Type and Release Option
Presentation (File Not Available for Download)
Start Date
4-20-2022 10:00 AM
End Date
4-20-2022 11:30 AM
Recommended Citation
Hassan, Mohammad Fuad, "Numerical and Experimental Analysis of an Elastohydrdynamic Seal For Gases" (2022). GS4 Georgia Southern Student Scholars Symposium. 24.
https://digitalcommons.georgiasouthern.edu/research_symposium/2022/2022/24
Numerical and Experimental Analysis of an Elastohydrdynamic Seal For Gases
Poster Session 1 (Henderson Library)
Supercritical CO2 (sCO2) power cycles are superior to traditional water-based, air-breathing, direct-fired, open Brayton cycles; or indirect-fired, closed Rankine cycles in terms of efficiency and equipment footprint. They hold great potential in nuclear power production, fossil fuel power plants, concentrated solar power, geothermal power, and ship propulsion. To unlock the potential of sCO2 power cycles, technology readiness must be demonstrated on the scale of 10 – 600 MWe and at the sCO2 temperatures and pressures of 350 – 700 ºC and 20 – 35 MPa for nuclear industries. The lack of suitable shaft seals at sCO2 operating conditions is one of the main challenges at the component level. So far, conventional seals are all incapable of handling sCO2 pressure and temperature in one way or another. In this study, we propose a novel Elasto-Hydrodynamic (EHD) high-pressure, high temperature, and scalable shaft seal for sCO2 turbomachinery that offers low leakage, minimal wear, low cost, and no stress concentration. The focus in this paper was to conduct a proof-of-concept study with the help of computer simulations. To this end, a fully coupled Fluid-Structure Interaction (FSI) modeling approach was adopted, and the simulations were carried out in COMSOL Multiphysics software. The modeling approached was presented thoroughly, the results were discussed, and the next research steps were highlighted. Under the EHD mechanism: the higher the pressures are, the tighter the sealing becomes, while still sustaining a continuous sCO2 film. For proof-of-concept purposes, a 2” diameter shaft static test rig was designed at Georgia Southern University before the actual dynamic testing at Sandia National Laboratories. For the sake of simplicity, the working fluid was chosen to be Nitrogen, and the tests were conducted at room temperature. The test rig consisted of a 16.5 MPA N2 tank, steel tubing with compression type fittings, an OMEGA – PX1009L0-5KSV pressure sensor to measure the pressure of the N2 after the pressure regulator from the tank, a chamber housing the 2” steel shaft and EHD seal (two prototype steel seals with seal clearances of 25 µm and 50 µm), a CONAX – K-INC12-U-T3(5FT)-7.5" temperature sensor to collect temperature data in the chamber, and an OMEGA – FMA-1601A mass flow meter with temperature and pressure measurement capability to evaluate conditions after the test chamber. The pressure, temperature, and mass flow rate data were collected via a National Instruments DAQ – Module NI-9205 and a LabVIEW program. The tests were conducted for an inlet pressure of 0.1 ~ 15 MPa and at two different clearances of 25 µm and 50 µm. The mass flow rate exhibited a quadratic trend with increased pressure, which proved the hypothesis.
