1. The Spread of Fire from Adjoining Vehicles to a Hydrogen Fuel Cell Vehicle Japan Automobile Research Institute Yohsuke Tamura, Masaru Takabayashi, Masayuki Takeuchi and Mitsuishi Hiroyuki.

2. 2 Thermal PRDs are safety devices intended to avoid rupture of the vessels by releasing the fuel. Fire phenomenon of HFCV is different from gasoline vehicle. Hydrogen flame In the process of HFCV widespread, HFCV will cause a fire with other fuel vehicles. Example: Crash fire between HFCV and Gasoline vehicle Hydrogen vessel for Vehicle

5. Just before TPRD activation 1second after TPRD activation

6.  It is necessary to examine the spread of fire with adjoined vehicles including FCV for safety design against fire of parking, tunnels, ferries and car carriers.  As the first step, we implemented two fire tests.

7. 1) Fire test on juxtaposed gasoline vehicle and HFCV 2) Multiple-HFCV fire test assuming a car carrier － Direct cause of fire spread from fire origin vehicle to adjacent vehicle － Fire spread behaviour 7

8. 1) Fire test on juxtaposed gasoline vehicle and HFCV 2) Multiple-HFCV fire test assuming a car carrier Contents 8

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11. 11 When the gasoline vehicle caught fire at 58 min., HFCV had already been burned down. The adjoining gasoline vehicle was not ignited by the hydrogen flames generated through TPRD activation but by flames from the exterior and interior fittings of the fire origin vehicle.

12. 12. PRD activation The hydrogen flames curled up on both sides of the HFCV’s body.

13. 1) Fire test on juxtaposed gasoline vehicle and HFCV 2) Multiple-HFCV fire test assuming a car carrier Contents 13

14. 14 Fire scenario  The transportation of vehicles in a car carrier ship is simulated with regard to vehicle placement and keeping all the vehicle windows shut.  A fire accident occurs involving only the vehicles parked on one floor of a car carrier ship.

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17. 17 The cause of fire spread from fire origin vehicle to adjacent vehicle is the flames spreading from the interior and exterior fittings of the fire origin vehicle – not the hydrogen flames from TPRD activation. However, after TPRD activation, the FCV’s fire spread rapidly.

18. The direct cause of fire spread from fire origin vehicle to adjacent vehicle is the flames spreading from the interior and exterior fittings of the fire origin vehicle – not the hydrogen flames from TPRD activation. However, hydrogen flame by TPRD of a HFCV, in turn may activate the TPRD of adjoining HFCV. 18 1)Fire test on juxtaposed gasoline vehicle and HFCV 2) Multiple-HFCV fire test assuming a car carrier  To minimize damage by HFCV fire, therefore, it is important to realize early detection and extinguishing of fire before the TPRD activates

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22. 22 Time(min:sec)Fire Spread Process 0:00:00 Test start (HFCV-A’s rear bumper ignited by burner.) 0:44:35 Explosion noise in HFCV-A (“A”) cabin; the rear bumper burning down. 98:36 Flames visible in “A” cabin. 99:31 “A” rear window begins to crack. 99:49 Flames spout from “A” rear tire. 102:10 “A” rear windows crack. RaginHFCV-B ignition g flames arise. 105:24 “A” right rear window breaks. 107:58 “A” left rear window breaks. 109:09 “A” left center window breaks. “B” ignited at its right rear panel. 111:56 Raging flames arise from “A” right rear window. 112:36 Raging flames arise from “A” right rear tire. 114:22 Explosion noise in “A” cabin. “C” ignited at its front bumper and engine hood. 115:59 “B” left rear window breaks; right rear tire bursts. 116:53 Raging flames arise from “B” rear window. 117:15 “A” rear TPRD is activated; start of hydrogen gas release. Hydrogen flames reach “C” front body and “B” rear tire. 117:49 “B” right center window breaks. 117:52 Explosion noise in “A” cabin. 118:46 Hydrogen release from “A” ends. “B” body burns down. “C” front body burns; its front tire bursts. 119:42 “A” right rear tire bursts. 119:47 “B” rear TPRD is activated (2 min. 32 sec. after activation of “A” rear TPRD). 120:43 “B” front window breaks. 122:14 “A” front TPRD is activated (4 min. 59 sec. after activation of “A” rear TPRD). Start of hydrogen gas release from “A” front TPRD. 124:14 Hydrogen gas release ends.

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24. 24 After the ignition of HFCV-B, temperature at its rear tank’s end plug (BTR_END) gradually increased.about 117 min. later the temperatures all over the rear tank climbed rapidly, following the activation of HFCV-A’s rear TPRD. About 3 min. after this temperature climb, the rear TPRD of HFCV-B activated; however, HFCV-B’s front tank was hardly affected by the TPRD activation in HFCV-A..

25. 25 Although temperatures on the front tank did not change for some time after HFCV-C’s ignition, the temperatures suddenly climbed after the activation of HFCV-A’s rear TPRD.