Onboard Compressed Hydrogen Storage: fast filling

Transcription

1 IA HySafe and JRC IET Workshop Research Priorities and Knowledge Gaps in Hydrogen Safety October 212, Berlin, Germany. Onboard Compressed Hydrogen Storage: fast filling P. Moretto, B. Acosta-Iborra, D. Baraldi M.C. Galassi, N. De Miguel, R. Ortiz Cebolla Institute for Energy and Transport, JRC/EC, Netherlands

2 Storage Technology Volumetric Density [kg Hydrogen /m 3 ] system Theoretical cylindrical tanks (increasing pressure) Steel tank Type IV tank Target Liquid H commercial tanks Gravimetric density [1*kg Hydrogen /kg system ] [%]

3 The RCS Status Requirements to qualify hydrogen storage systems for on-road passenger vehicles International standards SAE-J2579 Technical Information Report for Fuel Systems in Fuel Cell and Other Hydrogen Vehicles ISO/TS 15869:29 Gaseous hydrogen and hydrogen blends -- Land vehicle fuel tanks Regulations Commission Regulation (EU) No 46/21 JARI is updating the Japanese regulation International effort for regulations (UN-ECE) Global Technical Regulation for Hydrogen Fuelled Vehicles (GTR HFV) 212 under approval

4 Car Refuelling Stations Interface SAE protocol J261: Fueling Protocols for Light Duty gaseous Hydrogen surface Vehicles, March 21 It considers different types of refuelling stations: Type A - Station has -4 C pre-cooling Type B - Station has -2 C pre-cooling Type C - Station has C pre-cooling Type D - Station has no pre-cooling and 2 different type of re-fuelling protocols: Non-communication between the vehicle and the refuelling station (only pressure and ambient/external T) Communication e.g. including also T inside the tank

5 Fast Filling The refuelling of a hydrogen car/bus with compressed hydrogen tank has to take place in approximately 3 minutes 5 to 2 g/s! This industrial requirement has been defined by comparison with fillings times for other fuels. (In other words, on assumption on the average patience of a driver at a filling station). From material and safety considerations point of view however, the maximal temperature in the tank cannot exceed 85 C, so that pre-cooling of hydrogen is required in many cases.

6 Fast Filling Refuelling: technological fundamental questions to improve process How to measure the mass flow rate with the required accuracy in the re-fuelling station? (metering issue: the bill for consumers!) The requirement to pre-cool hydrogen is lowering process efficiency and it increases system costs: are there alternatives? The criterion of < 85 C: is it valid for local, short time events? How is the degradation of the properties material under these conditions? How conservative is the criterion?

7 Pneumatic test Pressure Holding time typically - 3 min P max Typically nominal pressure P min Gap between cycles Typically 2 bars Fuelling time max 3 or 5 minutes Defuelling time typically.5 1 hr Time

8 Experiments Full cycle Pressure Internal T5 8 6 Bar 4 4 C 3 T Boss T Bottom Time (min) -2

9 Experiments The filling phase with and without pre-cooling (Hydrogen) T gas without pre-cooling (pos 5) 8 5 Pressure 6 Bar 4 4 C T gas with pre-cooling (pos 5) Time (min) -2

10 CFD Validation Experiment: bar filling time 245s and 33 s Tgas=Tamb=294K (21ºC) TEXT 1 TC5 TC3 TC3 TC6 TC6 TC1 TC1 TEXT 2 TEXT 3 1s

11 CFD Validation Comparison between simulation and experiment TEXT 1 Temperature Distribution - top 4 TC5 TC3 TC3 39 TC6 TC6 TEXT 2 TC1 TC1 37 TEXT 3 35 Temperature Distribution - bottom T [K] exp T [K] 33 t [s] exp t [s]

12 CFD Validation Results: Maximum temperatures at the end of the filling procedure Test H Maximum Temperature 1. T [C] TC1 Maximum Temperature TC3 TC5 TC6 TCs Position TCEXT1 TCEXT2 Test H TCEXT err [% exp calc err T [C] T [C] TC1 Pos1 Pos1 TC3 TC5 Maximum TCs Position Temperature TC exp calc err err [% err [% 2 2. TC1 TC3 TCs Position TC5 TC6. exp calc err

13 Simulations Mass flow rate effect Calculation with pre-cooling

14 Some Fast Filling Gaps CFD validation with broader range of conditions e.g. initial conditions, pre-cooling, different tank size and geometry. Development and validation of accurate engineering correlations that can be applied in re-fuelling stations. Accurate measurement of mass flow rate. Filling strategy that can work without pre-cooling or with minimum use of pre-cooling. Are 85 C too conservative?

15 References 1. SAE J2579 Technical Information Report for Fuel Systems in Fuel Cell and other Hydrogen Vehicles, SAE International, Issue ISO/CD Gaseous hydrogen and hydrogen blends Land vehicle fuel tanks, ISO Commission Regulation (EU) No 46/21 of 26 April 21 implementing regulation (EC) No 79/29 on type-approval of hydrogen-powered motor vehicles. Off J Eur Union L 122/1e UN ECE WP.29 GRSP, Informal Group on Hydrogen and Fuel Cell Vehicles - Sub group safety (HFCV-SGS), Draft GTR on Hydrogen Fuelled Vehicles, February Acosta B., Moretto P., Frischauf N., Harskamp F., GASTEF: The JRC-IE Compressed Hydrogen Gas Tanks Testing Facility, Proceedings of the Eighteenth World Hydrogen Energy Conference, May 21, Essen. 2. Acosta B., Moretto P., Frischauf N., Harskamp F., Bonato C., Fast Filling and Permeation Experiments at the JRC-IE GasTeF Facility, Proceedings of the Fourth International Conference on Hydrogen Safety, September 211, San Francisco. 3. Galassi M.C., et al., Validation of CFD Models for Hydrogen Fast Filling Simulations, Proceedings of the Fourth International Conference on Hydrogen Safety, September 211, San Francisco. 4. Galassi M.C. et al., CFD analysis of fast filling scenarios for 7 MPa hydrogen type IV tanks, International Journal of Hydrogen Energy, 37 (212),