Freeze of Nozzle/Receptacle during Hydrogen Fueling Wataru Hiraki1, Hiroyuki Mitsuishi1 1Japan Automobile Research Institute

Hydrogen station Compressor Pressure vessel Dispenser FCV http://hysut.or.jp/ Overpressure Pressure [MPa] Overheat Temperature [°C] Overfill 85 70 15 SOC 100% 87.5 -40 use Pre-cool Hydrogen station is possible about fast-fueling safely, using pre-cool

Issue of nozzle/receptacle freeze lock Disconnection Freeze lock Ice forms during fueling which causes the nozzle and receptacle to freeze together. This phenomenon is not specific to a single nozzle/receptacle design.

Object Safety evaluation of the nozzle/receptacle freeze lock Confirmation of a water amount to cause the freeze lock

Test condition & Experiment setup Fueling gas: Hydrogen, 35 MPa Nozzle Receptacle Thermocouple T Gas Sensor Incubator N2 Nitrogen Gas temperature: -40°C Ambient temperature: 30°C Hydrogen Ambient humidity: 95 %RH Flow rate: 650 g/min Fueling time: 3 min Test interval: 10 min Nozzle: A, B(Two types) Water added : Nozzle, Receptacle Condition for the end of the test: Freeze lock occured or pass for 5 times

Experiment setup Receptacle Incubator Nozzle connected nozzle

Disconnect procedure Procedure for identification of freeze lock (1) Slidable locking sleeve is released (2) Draw out the nozzle 　⇒ 　disconnect Receptacle Nozzle Chuck Sleeve Receptacle Nozzle Chuck Sleeve (1') Chuck goes up Receptacle Nozzle Chuck Sleeve (※Shape of the sleeve and inner chuck are estimated) Procedure for identification of freeze lock Check immediately after the fueling Action for the disconnection; Revolve → Release the locking mechanism → Draw out Identify as freeze lock if the nozzle is not disconnected in the above condition

Water Spraying Position Nozzle Receptacle Chuck Sleeve Hydrogen Gas Line Pin Cover spray Nozzle Receptacle Fitting part Fitting part

Release the Locking mechanism Freeze lock Nozzle Water added Results Freeze lock Revolve Release the Locking mechanism Darw out A Receptacle 2nd fueling possible impossible

Release the Locking mechanism Freeze lock Nozzle Water added Results Freeze lock Revolve Release the Locking mechanism Darw out A Nozzle, Receptacle 1st fueling possible impossible

Release the Locking mechanism Freeze lock Nozzle Water added Results Freeze lock Revolve Release the Locking mechanism Darw out B Receptacle 5th fueling possible impossible

Release the Locking mechanism Freeze lock Nozzle Water added Results Freeze lock Revolve Release the Locking mechanism Darw out B 1st fueling possible impossible

Result Freeze lock is caused by water inside the nozzle. Hydrogen does not leak from the nozzle/receptacle even if the nozzle/receptacle were freeze lock. Freeze lock does not cause any damage of the equipment.

Estimation of freezing part Result Incidence Revolve Release the Locking mechanism Draw out possible impossible 14/16 (Nozzle A) 13/14 (Nozzle B) Clearance of sleeve Chuck part Fitting part Receptacle Nozzle Chuck Sleeve Estimated freezing part：Clearance of sleeve, Chuck part

Water injection method Effect of a water amount on freeze lock Water injection method Micropipette Nozzle head Water is injected to the nozzle inside before fueling. Connect to receptacle and flow -40°C gas Freeze lock?

Test condition & Experiment setup Nozzle Receptacle Thermocouple T Gas Sensor Incubator N2 Nitrogen Fueling gas: Hydrogen, 35 MPa Gas temperature: -40°C Ambient temperature: 30°C Hydrogen Ambient humidity: 60 %RH Flow rate: 650 g/min Fueling time: 3 min Nozzle: A Water added : injection the Nozzle

Release the loking mechanism Result of Quantification Water injection [μL] Results Revolve Release the loking mechanism Draw out 500 possible 750 1000 impossible After fueling Freeze lock

Conclusions ・ The nozzle and the receptacle are safely, even if the freeze lock occurred ・ The freeze lock is caused by the water freezing in the locking mechanism of the nozzle ・ The freeze lock occurred after fueling when water of 1000 μL over 750 μL injected to the nozzle A

Next step Experiment of the freeze lock Investigation of the freeze lock with other nozzles. Investigation of ambient condition when the freeze lock occurs. Investigation of a technique that protect the freeze lock. Proposition of the freeze lock testing condition and procedure

Thank you for your attention ACKNOWLEDGEMENTS This study is a summary of the “Hydrogen Using Technology Research and Development Project”, and the "Hydrogen production, transportation and storage system technology development" under consignment by the New Energy and Industrial Technology Development Organization (NEDO). Thank you for your attention