The Temperature Profile of Rectangular Fuel Source Jet Fire with Different Aspect Ratio

With more and more natural gas has been transported by pipelines, the possibility of natural gas jet fire caused by inner or outer factors is increased gradually. That will result in casualties and domino effect to make further disaster and serious loss of property. It is imperative to study jet fire and prevent jet fire happening. This paper investigates the temperature profile for square and rectangular fuel nozzle (long side sets along transverse) horizontal jet fires. The numerical simulation code was carried out to simulate jet fires with different jet velocity varied from 27.5 m/s to 205.8 m/s. The fuel leak area for square and rectangular was same (400 mm2), but the aspect ratio (width / length, W/L) were 1:1 and 1:4, respectively. Results show that the temperature increase with the jet velocity, and the relationship between maximum temperature along centreline and jet velocity is closed to line which slope is 1.82. The simple function for this connection was established. The maximum temperature of vertical direction locates at 1m from centreline, and the maximum temperature increase with jet velocity. The temperature along centreline for rectangular flame is less than square flame at same point and the high temperature area along horizontal direction is less. It is deduced the rectangular nozzle results in flame shorter and more width due to larger relative surface area and air entrainment. The high temperature area in transverse direction for rectangular nozzle is greater than square.