MULTI-FUNCTIONAL FIRE ENGINE USING LIQUID NITROGEN AS JET POWER AND MIXING JETTING GUN

A multi-functional fire engine using liquid nitrogen as jet power, comprising a vehicle body (1), a liquid nitrogen storage tank (2), a liquid nitrogen conveying pipeline (9), a gasification device (15), a liquid nitrogen jetting gun (13), a water supply joint (12), and a mixing jetting gun (8); liquid nitrogen is mixed with water in the mixing jetting gun (8) and the liquid nitrogen quickly absorbs the heat of the water and rapidly gasifies, the volume thereof expanding hundreds of times while simultaneously generating thrust; thus the water is ejected at a high speed in the form of atomized fluid, and the atomized fluid increases the contact area of a fire extinguishing agent to a flame, thereby improving the efficiency of fire rescue; and further provided is a mixing jetting gun (8), comprising a first input terminal, a second input terminal, a liquid nitrogen nozzle (8-4), and a jetting pipe, wherein a contraction section (8-1), an expansion section (8-2) and a speed increase section (8-3) are split and connected in an inner cavity of the jetting pipe according to the flow direction of a "gas-liquid" mixture; the liquid nitrogen nozzle (8-4) is connected to the first input terminal, and an outlet of the liquid nitrogen nozzle is at the same level as an outlet of the contraction section (8-1); an end of the second input terminal is connected to the contraction section (8-1), and the other end is connected to the water supply joint (12); by means of the mixing jetting gun (8), kinetic energy generated from a phase change of heat absorption when liquid nitrogen is mixed with water may be utilized, and the water may be ejected at a high speed in the form of atomized fluid, and may simultaneously prevent an "air block" phenomenon from occurring due to a sharp increase in volume when the liquid nitrogen gasifies in the mixing jetting gun (8).