Task 1A: Transport Property Measurements of Pressurized Liquid Oxygen and Liquid Hydrogen

Transcription

1 Task 1A: Transport Property Measurements of Pressurized Liquid Oxygen and Liquid Hydrogen Steven W. Van Sciver - PI Scientific Staff: Dogan Celik, David Hilton (postdoc) Technical Staff: Scott Maier Undergraduate students: Steve Lydzinski, Ali Hemmati Cryogenics Group Mechanical Engineering Department National High Magnetic Field Laboratory Florida State University Start Date = 6/2002 Planned Completion Date = 12/2006

2 Research Goals and Objectives Establish the capability to perform precision (accuracy < 1%) measurements of the transport properties (thermal conductivity & viscosity) and density of cryogenic liquids. Conduct transport property measurements on LO 2 and LH 2 in the subcooled liquid regime where the data are sparse or non-existent (T tp < T < T NBP and pressure up to ~ 1 MPa). Compare results with existing property data bases (REFPROP) Where appropriate, develop improved correlations to describe fluid properties Investigate related physical conditions that can affect transport properties

3 Relevance to Current State-of-the-Art Transport property data on LO 2 and LH 2 in the literature are quite old (1960s and 1970s) FSU program is the only current effort on measuring cryogen transport properties Higher precision in the data sets through improved instrumentation and measurement techniques Relevance to NASA NASA uses LO 2 and LH 2 for propulsion systems for which transport properties are of critical importance Many systems use subcooled liquid to increase density, but available data are very limited FSU measurement capability could be used for property measurements of other fluids of interest to NASA and other groups

4 Budget, Schedule and Deliverables Milestones: (Bold tasks are complete) Complete LH 2 density measurements 3/31/05 Attend NASA Review 5/10/05 Presented paper at the Space Cryogenics Workshop 8/25/05 Complete LO 2 viscosity measurements 10/30/05 Attend NASA Review 11/1-4/05 Modify viscosity apparatus for LH 2 measurements 12/1/05 Complete LH 2 thermal conductivity measurements 12/1/05 Preliminary LH 2 viscosity data 12/31/05 Complete LH 2 viscosity data mid-2006 Final report 12/31/06 Deliverables: Report containing data and analysis of transport properties of subcooled LH 2 & LO 2. Description of test apparatus and computational tools developed. Copies of all resulting publications. Budget: $270,000 for 1/1/05 to 12/31/05 to cover staff salaries, equipment and travel.

5 Accomplishments and Results LO 2 Measurements Density measurements completed. Achieved 0.028% precision in dielectric coefficient (κ) measurements and corresponding liquid density (ρ) Thermal conductivity (k) measurements completed to 0.24% precision Kinematic viscosity (ν) measurements complete with an error of < 1% LH 2 Measurements Ortho-para H 2 converter apparatus completed and tested LH 2 density (ρ) measurements complete to 0.11% precision (He solubility in LH 2 ) Preliminary thermal conductivity (k) measurements Kinematic viscosity (ν) experiment currently being modified for LH 2 measurements Other Hydrogen Experiments Performed literature search on He solubility in LH 2 (PVT mass gauging) Prototype Acoustic Hydrogen Detector (AHD) developed

6 Thermal Conductivity/Density Measurement Apparatus Instrumentation: A/C Resistance bridge Capacitance meter Pressure gage Temperature controller Labview Cold trap Pressure gage Valve O 2 He Vacuum pump Cryocooler Thermal link Vacuum/heat exchange gas Experimental cell Vacuum can Liquid oxygen/hydrogen Capacitor/Guarded Hot- Cold Plate assembly Cryostat

7 κ Florida Universities Hydrogen Review 2005 LO 2 Dielectric Coefficient (κ) /Density (ρ) MPa MPa MPa MPa T(K) Co-axial cable (shield and core) Shield Capacitor plate Spacer Insulator (κ-1)/(κ+2)ρ -1 (cm 3 /g) New Correlation: 1 κ 1 = C 1 + C 2 ρ+c 3 ρ 2 + C 4 ρ 3 ρ κ ρ (g/cm 3 ) Predicts density of oxygen to better than: 0.005% for compressed liquid 0.08% for compressed gas 0.03% for saturated liquid (except near critical point) Ref. [3] Ref. [2] This research Fit to all

8 p-h 2 Dielectric Coefficient (κ) Measurement κ Y X ρ (g/cm 3 ) Stewart This Research Measurement Uncertainties δp < MPa δt < K δκ < (0.025%) δρ < 0.11% Stewart, J.W., J. Chem. Phy. 1964;40:3297. T: K, P: MPa This Research: T: K, P: MPa These results are still being analyzed in terms of Clausius-Mossatti relation vs density

9 LO 2 Thermal Conductivity (k) Measurements MPa MPa MPa MPa k(w/m-k) k(w/m-k) K 70 K 80 K Refprop, 60K Refprop, 70K Refprop, 80K Laesecke, 70K Laesecke, 80K Exp. 70K (1+1%) Exp. 70K(1-1%) T(K) P(MPa) Measurement Uncertainties: δp < MPa; δt < K; δk < W/m-K (0.24%)

10 Viscosity Measurement Apparatus Log z Cell attached to cryocooler Capillary viscometer cell g z 1 z 0 t R R p 0 p 0 z 2 p 1 p 2 L 4 gr ν = 2 4R L τ ν ρ, µ r

11 LO 2 Dynamic Viscosity (µ) Results Subcooled Liquid Oxygen Dynamic Viscosity vs. Pressure Pressure Coefficients 60 K µ [µpa.s] NHMFL NIST 600 T = 60.0 K Sl ope: µ [µpa.s] K µ [µpa.s] P [kpa] P [kpa] 185 NIST NHMFL P [kpa] Comparison to NIST REFPROP

12 Ortho/Para Conversion of H 2 n-h 2 (75% ortho +25% para) Catalyst p-h 2 Vacuum/Exch. gas LHe Vacuum/Exch. gas Thermometer Heater Vapor Pressure (torr) Souers, P.C., Hydrogen Properties for Fusion Energy, U of California Press, 1986 This research p-h2 (Souers) n-h2 (Souers) Uses hydrous ferric oxide (Fe(OH) 3 ) catalyst Ortho/para ratio determined based on ~3% difference in vapor pressures of p-h 2 and n-h 2 (75% ortho + 25% para) T(K)

13 Vapor-Liquid Equilibria in Para-H 2 -He System Helium-hydrogen vapor mixture Dielectric measurement Valves T P He H 2 Calibrated volume Liquid level gauge Thermal conductivity measurement Vital for the accuracy of PVT mass gauging technique. Data does not exist below 20.4 K Dielectric coefficient and thermal conductivity measurements both in liquid and vapor Precise measurement of helium gas amount in the experiment Combined with appropriate mixing rules give the amount of helium dissolved Liquid parahydrogen with dissolved helium

14 Helium Solubility Case Study: Resolution of the current apparatus: κ to +/ ; k to +/ W/m-K This resolution should be sufficient to determine the He in LH 2 kmix. (He+Liquid H2), W/m-K % He Mole Fraction in Liquid H2 kmix. (He+Liquid H2) % He Mole Fraction in Liquid H2 Dielectric Coeff. (He+Liquid H2) % He Mole Fraction in Liquid H2 Dielectric Coeff. (He+Liquid H2) % He Mole Fraction in Liquid H P(He, psia) P(He, psia) Change in the thermal conductivity and dielectric coefficient as a function of pressure (n-h 2, T=15.50 K, 10<P he <150 psi)

15 Acoustic Hydrogen Detector (AHD) Development 40 khz Detector 1 Acoustic Generator Air + H 2 Detector 2 Air out Electronics box that detects the phase shift between the two resonances Matching Resonator Resonator with bell jar Air in Air + H 2 Hydrogen Leak Hydrogen gas or liquid line

16 1.2 Acoustic Hydrogen Detector (Test Results) Hydro g e n Gas De te c tio n (T = 20 C, P = 1 atm) 1.0 Hydro g e n Gas De te c tio n (T = 20 C, P = 1 atm) Normalized Signal [-] ml 2 ml 3 ml 4 ml Peak Signal [-] Time [s ] Gas Volume [ml] Response of the AHD to a small quantity of H 2 gas being injected under the collection cone. Peak signal from the AHD versus H 2 gas injected. Note that the range of sensitivity can be adjusted by collecting the H 2 in the detector

17 Future Plans (2006) 1. Complete the measurements of the transport properties of LH 2 as originally proposed. Compare results to database codes (REFPROP). Publish results in the literature. 2. Develop capability to measure He solubility in LH 2 using both dielectric constant measurements and thermal conductivity measurements. Compare to PVT measurement of gas injected. 3. Complete development of the Acoustic Hydrogen Detector. Quantify performance for varying leak rates. 4. Seek additional funding to support transport property experiments

18 Publication & Presentations Thermal Conductivity Measurements of Subcooled Oxygen below 80 K T. Kucukomeroglu, D. Celik and S.W.Van Sciver. Advances in Cryogenic Engineering, ed. by Waynert, J., et. al, Vol. 49, pp , Dielectric Coefficient and Density of Subcooled Liquid Oxygen, Celik, D., Van Sciver, S.W., Cryogenics Vol. 45, (2005) Thermal Conductivity of Subcooled Liquid Oxygen, D. Celik and S.W. Van Sciver, Cryogenics Vol. 45, (2005) "Pressurized Rankine Viscometer for Kinematic Viscosity Measurements from 0.1 to 1.0 MPa of Liquefied Gases, D. K Hilton and S. W. Van Sciver, APS Division of Fluid Dynamics 57th Annual Meeting, Nov. 2004, Seattle, WA Ortho and Para Hydrogen Concentration Determination Based on Vapor Pressure, S.R. Lydzinski, D. Celik, A. Hemmati and S.W. Van Sciver, Advances in Cryogenic Engineering, Vol 51A (to be published) High Precision Transport Properties Measurements of Liquid Propellants, D. Celik, D.K. Hilton and S.W. Van Sciver, 2005 Space Cryogenics Workshop, Colorado Springs, CO, August 24-26, 2005.