CHARACTERISTICS OF A WATER SPRINKLER SYSTEM WITH VARIABLE FLOW RATES TO MELT SNOW ON RAILWAY TRACKS

Abstract

This chapter discusses the construction, experiments, and the characteristics of a water sprinkler system with variable flow rates in response to weather conditions for snow-melting in railway tracks. It is indispensable for high-speed railway lines running through snowy areas to eliminate the snow deposit from railway tracks. It is important from a standpoint of system performance and economy to provide a variable sprinkling water flow in response to snowfall intensity and atmospheric temperature. To construct such a system, two things must be done: one is to develop a sprinkler that maintains a constant water droplet flying distance even in variable water flow and the other is to develop a variable-flow water sprinkling model to be controlled by water pressure. The chapter describes an experiment that was done to study the sprinkled water distribution and the heat loss of sprinkled water. The sprinkled water distribution and the heat loss of sprinkled water were measured by a conventional method, and photographic method was used to measure the diameter and the velocity of water droplets flying through the air. Unsteady state analysis was carried out by a numerical technique for both motion loss and heat loss in flying water droplets. A performance test following the construction of an experimental model was carried out by inverter pump-controlled operation. The sprinkling distances of flying water droplets after leaving the sprinkler nozzle were affected by sprinkling water pressure, levitation angle, sprinkled from nozzle, diameter of flying water droplet, and wind velocity.