Technology Readiness of 5 th and 6 th Generation Compliant Foil Bearing for 10 MWE S CO 2 Turbomachinery Systems

Transcription

1 Technology Readiness of 5 th and 6 th Generation Compliant Foil Bearing for 10 MWE S CO 2 Turbomachinery Systems H. Heshmat, J. F. Walton and J. L. Cordova The 6 th International Supercritical CO 2 Power Cycles Symposium March 27 29, 2018, Pittsburgh, Pennsylvania Presenting Author Copyright MiTi 1

2 Overview Objectives Background Technology Summary and Conclusions Copyright MiTi 2

3 MITI Oil Free Turbomachinery Compressors Hydrogen Blower Fuel Cell Compressor Air Cycle Machine Hydrogen Pipeline Compressor 1 kw 12 kw 30 kw 200 kw 360,000 rpm 120,000 rpm 120,000 rpm 60,000 rpm 3

4 MITI Oil Free Turbomachinery Energy Gas Turbine Generator Flywheel Electromechanical Battery ORC Turbogenerator 8 kwe 60 kwe 65 kwe 180,000 rpm 60,000 rpm 30,000 rpm 4

5 Objectives Identify Turbomachinery Concepts Capable Of Operating Efficiently With s CO2 Identify Key Enabling Bearing Technology Oil Free Compliant Foil Bearings Use s CO2 Process Fluid for Hydrodynamics and Thermal Management Scalable For Multi Megawatt Turbomachinery Applications from kw to 100s of MW Copyright MiTi 5

6 Preliminary Cycle Analysis for Net 10 MW System Sink 7.9 MPa 8.0 MPa Source 18.1 MPa 750 C 128 kg/s Main Compressor Re Compressor 18.4 MPa 18.3 MPa 60 krpm P = 11 MW e Low T Recuperator High T Recuperator Copyright MiTi 6

7 Preliminary 1 st Order Aero Analysis Copyright MiTi 7

8 Turbine Rotor Concept 35.6 cm (14 inch) 53.3 cm (21 inch) Copyright MiTi 8

9 5 MW Turbo Compressor (2x) Compressor Discharge Turbine Inlet Compressor Inlet Thrust Bearings Turbine Discharge Journal Bearings krpm Copyright MiTi 9

10 General Bearing Characteristics Incompressible Fluid Compressible Fluid/Gas Compressible Fluid Film Bearing Compliant Foil Active Magnetic Rolling Element Rigid Incompressible Fluid Film Bearing Rolling Element Bearing Fluid Film 20 Speed 0 0 Speed or Reynolds No. Copyright MiTi 10

11 Foil Bearing Fundamental Mechanisms Coating K Hydro B Hydro B Struct K Struct Copyright MiTi 11

12 MiTi Korolon Coated Foil Bearings Demonstrated with Different Process Fluids Air, H2, He (H2+H2O) R134a, 245fa, R1233zd & R1234yf, s-co2 2-Phase Flow Copyright MiTi 12

13 Complexities of Mechanisms Copyright MiTi 13

14 Normalized Foil Compliancy Matrix 10 (leading edge) Extent of Bearing pad surface compliancy 350 (trailing end) Copyright MiTi 14

15 Foil Bearing Film Pressure and Height.... Copyright MiTi 15

16 Comparison of Rigid vs Compliant Bearings at 60,000 rpm 2,000 1,750 1,500 Foil Bearing Compressible Maximum Load (lbs) 1,250 1, Rigid Bearing Compressilbe Eccentricity Ratio Copyright MiTi 16

17 s CO2 Foil Bearing Characteristics Dynamic Characteristics Load Performance Min Film (mils) & Power (HP) Inch Diameter Foil Bearing Performance vs Eccentricity ratio at 60 krpm Power Loss Stiffness 1.20E E E E E E E E+06 Stiffness (lb/in) Film Pressure, Load and Stiffness With Turbulence 4.00E+06 Min. Film Height E Eccentricity Ratio HN (mils) P (HP) KXX KXY KYX KYY Copyright MiTi 17

18 Foil Bearing for 100 MW Scale 3150 lb Turbine Speed Dependent SCO2 Foil Bearing Stiffness 1.50E E+07 Stiffness (lb/in) 5.00E E E ,000 4,000 6,000 8,000 10,000 Speed (rpm) KXX KXY KYX KYY Copyright MiTi 18

19 Scalability of Foil Bearings from 1 to 100s MWe Copyright MiTi 19

20 Bend Testing After 815 C Thermal Cycling Korolon TM 1350A coated foil after 50 thermal cycles and bend testing 815 C Korolon Representative sets of thermal cycles for thin foils 95 C YSZ YSZ coated foil fractured after thermal cycling and bend testing Copyright MiTi 20

21 MiTi Bomb Setup to Expose Korolon Coated Foils to SCO2 at >675 o C and >80 Bar Copyright MiTi 21

22 Korolon Coated Bearing Foil Before & After Exposure to SCO2 Pretest Bend Posttest Bend Copyright MiTi 22

23 Post Exposure Tribological Test Copyright MiTi 23

24 MiTi Korolon Coated Foil Sample After Exposure to 650 C SCO2 and 500 Start/Stop Cycles Copyright MiTi 24

25 Measured High Temperature Foil Bearing Performance Copyright MiTi 25

26 Thermal Performance of Foil Bearing Gen IV Bearing Len x Diam = 100 x 75 mm 2 Copyright MiTi 26

27 5+ Hour Elevated Temperature Test Bearing Inboard Bearing Free End Bearing Chamber Temperature (C) Speed Speed (krpm) Time (Minutes) T16R3ABCD Copyright MiTi 27

28 High Temperature Foil Bearing 870 C 815 C Copyright MiTi 28

29 Bearing Housing and Foil Temperatures Bearing Shell Temperatures Bearing Foil Temperatures Copyright MiTi 29

30 Foil Bearing Generations/Classes Copyright MiTi 30

31 Summary & Conclusions s CO2 Turbomachinery is Compact and Operates at High Speed High Temperature s CO2 Environment Restricts Use of Conventional Bearing Technologies and Lubricant Systems Compliant Foil Gas Bearings Are an Enabling Technology Preliminary Testing Shows Korolon Coated 6 th Generation Foil Bearings Have Capabilities to Meet Needs for s CO2 Systems From kw to 300 MW High Temperature Testing to 870 C High Load Capacity High Speed with Low Power Loss Further Verification and Demonstration of Korolon Coated Foil Bearing Performance and Durability in High Temperature s CO2 is Underway Copyright MiTi 31

32 Acknowledgements U. S. Department of Energy under Award No. DE SC The authors particularly acknowledge the support of Mr. Brian K. Robinson at DOE. Thank you! Copyright MiTi 32

33 Backup Copyright MiTi 33

34 Compressibility of s CO2 Compressibility of Gas 10 Λ 6 Bearing Number/Compressibility MPa ~15 MPa Supercritical CO2 Compressible Incompressible Ambient Pressure (psia) Air_72F CO2_90F CO2_800F CO2_1200F Threshold P Threshold L 7.9 MPa Copyright MiTi 34

35 Copyright MiTi 35

36 Bearing Requirements/Environment Scaling Power Pressure Temperature Weight Speed (MW) (MPa) ( C) (kg) (rpm) , , , >5,000 5,400 Copyright MiTi 36

37 MITI Oil Free Bearings and Seals Journal Foil Bearing Thrust Foil Bearing Foil Face Seal Foil Radial Seal mm mm mm mm 100 psi / 870 C 80 psi / 650 C >80 psid / 650 C >100 psid / 870 C Copyright MiTi 37

38 Korolon Coated Foil Bearing Life Test Coefficient of Friction Friction During Shutdown Friction During Operation Running Coefficient of Friction Startup/Shutdown Cycles Copyright MiTi 38