Abstract: In order to avoid fire accidents in underground coal mine effectively, a piece of the mobile fire extinguishing equipment of liquid carbon dioxide for use in disaster areas was developed. An insulated storage tank embed in the equipment can reduce the influence of environment temperature on the low gas temperature condition. A self-pressure control system in the equipment can fill the equipment with the gas automatically or manually according to the under-pressure level during the drainage process. The characteristics of effective storage and large flow delivery of carbon dioxide, physical state transition in and out the pipeline, and the performance of covering and extinguishing the fire source were studied experimentally. The results show that for a vacuum degree of storage tank of 1.6 Pa, the effective volume of the liquid inside the 2 m³ tank is not less than 1.6 m³ after 48 days and the time of liquid discharge for a single tank is about 10.5 min, and that continuous gasification jet without ice blocking after a 100 m liquid horizontal delivery can be realized by using the nitrogen self-compensating pressurization technology.

Key words: underground disaster area, liquid carbon dioxide fire extinguishing, vacuum insulation, anti-ice block of self-pressurization, gasification jet