Abstract: A fire engine including a vehicle frame, a liquid nitrogen storage tank, a liquid nitrogen conveying pipeline, a gasification device, a plurality of electric valves, a water pipe adapter, a liquid nitrogen spray gun, and a mixed spray gun. The liquid nitrogen conveying pipeline includes a first pipeline and a second pipeline. The first pipeline connects the lower part of the liquid nitrogen storage tank, the gasification device, and the upper part of the liquid nitrogen storage tank sequentially in that order. The second pipeline connects the liquid nitrogen storage tank, an input end of the liquid nitrogen spray gun, and a first input end of the mixed spray gun. The mixed spray gun includes a first input end, a second input end, a liquid nitrogen nozzle, and a spray pipe. The spray pipe includes a contraction section, an expansion section, and an acceleration section.

Abstract: A fire engine including a vehicle frame, a liquid nitrogen storage tank, a liquid nitrogen conveying pipeline, a gasification device, a plurality of electric valves, a water pipe adapter, a liquid nitrogen spray gun, and a mixed spray gun. The liquid nitrogen conveying pipeline includes a first pipeline and a second pipeline. The first pipeline connects the lower part of the liquid nitrogen storage tank, the gasification device, and the upper part of the liquid nitrogen storage tank sequentially in that order. The second pipeline connects the liquid nitrogen storage tank, an input end of the liquid nitrogen spray gun, and a first input end of the mixed spray gun. The mixed spray gun includes a first input end, a second input end, a liquid nitrogen nozzle, and a spray pipe. The spray pipe includes a contraction section, an expansion section, and an acceleration section.

Abstract: The present disclosure provides a wireless terminal type identification method and system in a router bridge networking mode. The method includes: in the router bridge networking mode, capturing all communication data packets forwarded by a router and filtering all the communication data packets to obtain a DHCP request data packet of the communication between a wireless terminal and a DHCP server; parsing the DHCP request data packet to obtain a parsed value; and sending the obtained parsed value and a MAC address of the wireless terminal to a cloud-end server for a wireless terminal type query to obtain the type of the wireless terminal. Parsing parameter values of Option 12, Option 55 and Option 60 in the DHCP request data packet improves accuracy of terminal type identification. When being disconnected from the Internet, the router is capable of identifying the type of the terminal by querying a local database.