EFFECT OF DROPLETS CONVECTIVE HEATING AND THEIR EVAPORATION ON THE SHIELDING PROPERTIES OF FIRE-FIGHTING WATER CURTAIN

Abstract

Purpose. This work represents further development of earlier received results of simulation of water curtains used as fire protection walls. Subject of the theoretical analysis is the flat fan sprays which flow from the slot-hole sprinkler. The central objective of the study is theoretical research of processes of droplets convective heating and their evaporation in heated air near the fire seat and their influence on the shielding properties of a fire-fighting water curtain. Approach. In this study the earlier published literary data are applied to fulfill the calculations. The calculated formula allowed to have received numerical results for graphic dependence of droplet equilibrium temperature on air temperature. Other calculated formulae allowed to have executed calculations of the droplet evaporation time and of the time of droplet flight along an axis of a water curtain. According to the executed calculations, for typical parameters of water curtain the droplets heating and their evaporation owing to heat convection with hot air have no significant effect on the shielding properties of fire-fighting water curtain. Findings. Application of this formula to earlier developed mathematical model of thermal shielding allowed expanding its opportunities for practical use. This model can be used for designing of water curtains of fire-prevention appointment, and also for definition of optimum modes of their operation.