"Modelling and experimental verification of pressure wave following gaseous helium storage tank rupture"
M. Chorowski, M. Grabowski, A. Jedrusyna, J. Wach
ICEC 25 MCh, TE Seminar 12.11.09
ILC Helium Cryogenics in „Big Science”
FAIR XFEL
ITER LHC MCh, TE Seminar 12.11.09 Helium cryogenics in chosen projects Helium Installation, location, status Type inventory
LHC, CERN, Geneva, under operation pp collider 136 ton
FAIR, GSI, Darmstadt, early stage of ions accelerator 11 ton construction XFEL, DESY, Hamburg, advanced stage of free electron 5 ton construction laser W7-X, Max Planck Greifswald, fusion 2 ton commissioned in May 2014 stellarator ITER, Cadarache, advanced stage of fusion tokamak 24 ton construction ILC International Linear Collider, e+ e- lin. 100 ton conceptual design (Japan?) Collider
FCC Future Circular Collider, pp collider 500 ton first idea proposed (CERN?) MCh, TE Seminar 12.11.09 Medium pressure storage tanks at CERN site
Medium pressure gas storage tanks are significant energy containers.
3 Energy of 360 m gaseous helium container under pressure of 25 bar gives: Brode – 296 kg of TNT Baker – 216 kg of TNT Kinney – 597 kg of TNT. ITER Cryogenic System with GHe storage tanks
Gas storage tanks Cryodystribution lines and boxes in the tokamak building Main cryogenic transfer lines
Helium and nitrogen liquefiers in the cryoplant buildings MCh, TE Seminar 12.11.09
Energy storage in compressed gas:
Energy stored in 5 l tank pressurized to 4 bara V ⋅(p − p ) Brode E (p,V ) = amb E = 0.7029 grams of TNT Br κ −1
κ −1 p ⋅V p κ Baker amb E = 0.3236 grams of TNT EBa (p,V ) = ⋅ 1− (isentropic) κ −1 p
p Kinney = ⋅ ⋅ E = 0.5717 grams of TNT EKi (p,V ) p V ln (isothermal) pamb MCh, TE Seminar 12.11.09 TNT equivalent overpressure evaluation
The TNT-model proposed by Frazer-Nash for hydrogen explosion bases on the mTNT - mass of TNT energy equivalent in kg; r - distance in m, r 6,7 m ∆p (r,m ) = +1 Z(r,mTNT ) = s1 TNT 3 3 mTNT Z(r,mTNT )
∆ps1 (r,mTNT )⋅bar for ∆ps1 (r,mTNT ) >10 ∆pstat (r,mTNT ) = ∆ps2 (r,mTNT )⋅bar otherwise
2 5 ∆pstat (r,mTNT ) ∆pdyn (r,mTNT ) = ⋅ 2 ∆pstat (r,mTNT )+ 7⋅ pamb
pblast (r,mTNT ) = ∆pstat (r,mTNT )+ ∆pdyn (r,mTNT ) MCh, TE Seminar 12.11.09
Thermodynamic model pressure wave evaluation, comparison with TNT approach
Comparison of blast pressures Blast pressure at calculated by thermodynamic model – solid red line an TNT model – dashed the distance r blue line, 1 pressure tank 350 m3, 20 bar destroyed 5 5 .10 κ V He 5 ( ) = 4 .10 pTh r pHe Vsph (r) 5 3 .10 PTh(r)
PTNT(r) 5 The blast pressure is 2 .10 calculated on the
5 assumption of the gas 1 .10 sphere-like expansion
0 0 10 20 30 40 50 r Distance , m MCh, TE Seminar 12.11.09 Comparison of TNT equivalent and thermodynamic models estimations,3 x 360 m3 helium storage tanks simaltenous blast
Critical Distance in meters Criteria pressure TNT Thermodynamic 0.2 psi Debris and missile damage 195.0 13.7 0.014 bar 5 psi Eardrum rupture overpressure 29.5 12.6 0.345 bar 29 psi Lung damage overpressure 13.2 11.1 1.999 bar
TNT and thermodynamic model give similar results for short distances only, the models are in significant discrepancies for longer distances MCh, TE Seminar 12.11.09 Experimental test rig basic elements layout and general view MCh, TE Seminar 12.11.09 Location of the pressure sensors along the experimental test rig
The experimental tests were conducted for PET containers with a capacity of 2 and 5 liters. The containers have been pressurized with the nitrogen or helium in absolute pressure range from 4 bar to 10 bar. MCh, TE Seminar 12.11.09 The arrangement for the recording of the PET container bursting process MCh, TE Seminar 12.11.09 MCh, TE Seminar 12.11.09
Experimental results: 5 liters helium tank, 5,2 bara. MCh, TE Seminar 12.11.09 Comparison of TNT equivalent, thermodynamic model and experiment: 5 liters helium tank, 5,2 bara, non uniform tank rupture MCh, TE Seminar 12.11.09 Experimental results: 5 liters nitrogen tank, 6 bara. MCh, TE Seminar 12.11.09
Scaling of the test results for objects with higher pressures and larger volumes
Estimation of pressure increase profile caused by a single tank rupture or simultaneous rupture of 4 vertical tanks of 360 m3 volume and 25 bar is given as an example of the scaling method.
MCh, TE Seminar 12.11.09
The scaling results for 4 tanks of 360 m3, 25 bar, 300 K MCh, TE Seminar 12.11.09
Conclusions
• It is seen from the performed blast tests that thermodynamic model can be applied for calculation of pressure wave resulting from rupture of the tank filled with the compressed gas.
• Some discrepancies between thermodynamic model and experimental results are due to the fact that the measured pressure wave resulted from a jet like initial gas relieve from the container.
• In case of the uniform container blast thermodynamic model is in perfect agreement with the measurements.