Abstract: The new-type dry water fire extinguishing agent has a good fire extinguishing effect due to its high water content and special core-shell structure. In order to explore the fire extinguishing effect of dry water on wood crib fires, the modified dry water was prepared by adding ammonium dihydrogen phosphate and carried out small-scale wood crib fire extinguishing experiments. The results show that the dry water fire extinguishing agent can extinguish the fire without re-ignition, the fire control time of the modified dry water is only 8 s, and the flame height continues to drop rapidly during the fire control process, while the fire control time of the dry powder is 20 s, and re-ignition occurred 39 s after spraying. The temperature suppression effect of the modified dry water on the flame area and the wood crib was better than that of the dry powder. The average temperature drop rate is as high as 17.00 ℃/s, which is 1.94 times the average temperature drop rate under the action of dry powderduring fire control time. The modified dry water can effectively reduce the internal temperature of the wood crib, the average temperature drop rate in the center of the wood crib is 8.78 ℃/s during within 50 s of spraying, while the dry powder lacks cooling effect, and the average temperature drop rate in the center of the wood crib is only 6.10 ℃/s, which cannot effectively suppress smoldering.

Key words: modified dry water, fire extinguishing agent, wood crib fire, fire control time, average temperature drop rate