Abstract: In order to clarify the reliability of the extra-high voltage transformer station lifting fire robot to transport a variety of fire-fighting agents, Fluent was used for water, foam and compressed air foam in the pipeline with long-distance transport, height changes in the pressure drop numerical simulation study. The results of the study show that: in the range of supply flow 2 000~4 000 L/min, the pressure drop of the three extinguishing agents fluids in the hard pipe increases with the increase of flow rate, and the supply flow 4 000 L/min of each extinguishing agents pressure drop can be up to 3.4 times that of 2 000 L/min. At the same flow rate, the difference in pressure drop between foam and water is small, while the pressure drop of compressed air foam is much greater than that of water and foam. Affected by frictional resistance and local resistance, there is a large pressure drop at the hard hose connection port; changes in the height of the pipe nozzle have a significant effect on the rising section, the higher the height, the faster the pressure drop, the pressure drop coefficient of the pipe at a height of 15 m can reach 1.9 times that of the 6 m pipe.

Key words: multi-media flow, pipeline parameter, altitude change, numerical simulation, pressure drop