Flow simulation and verification of HFC-125 in recirculation zone.

The fire extinguishing agent particles absorb heat and evaporate into gas. Based on the HFC-125 injection experiment, the HFC-125 injection simulation model is established. Comparing the simulated values with the experimental values, simulated extinguishing agent flow pattern is consistent with the experiment. The errors between the simulated and experimental values of the free flow and the recirculation zone are within ±30 % and ±15 %, respectively. With the increase of wind speed, the simulated value of residence time is approximately equal to the experimental value. The error of the simulated characteristic mixing time is within ±30 %, and the error after the calculation of the modified model is within ±10 %. The corrected simulated characteristic mixing coefficient is 34.84, which is close to the experimental value. The reliability of the model is proved. The model is used to simulate the effect of different obstruction types on extinguishing agent flow. The results show that the semi-circular obstruction has the least influence on the flow of fire extinguishing agent, which is more conducive to extinguishing the fire in the recirculation zone.