Experimental Research Of Heat Conduction In Second Cooling Of Continuous Casting

Continuous casting process plays an important role in the steel works, with the improverequirements of the quality, diversification of varieties, production efficiency, saveing energyand reduceing consumption, we need to optimize the continuous casting process. when thecontinuous casting equipment and operation process are sure, the most controllable processis secondary cooling process. spray cooling is the main way to refrigeration the casting blank,we can avoid some defects such as surface crack, deformation, etc through good coolingeffect.in this context,we organized the aerosol jet cooling static heat transfer experiments,studied the essential feature of the heat conduction process, analysised varying pattern of thetemperture and the heat flux on the surface.In this paper we desired and builded an experimental facility for the experimentalresearch of heat conduction in second cooling of continuous casting, the experimentalfacility includes aerosol jet system, heating system, furnace bottom drive system, blockwater system and data collection and disposal system. It can imitate the second cooling ofcontinuous casting in the laboratory. analysis the temperature measurement veracity of theembedding and arrangement for the thermocouple using the ansys software.An inverse problem calculation method was established for the measurement of thesurface temperature,the surface heat transfer coefficient and the surface heat flux by thetemperature measured by the internal thermocouple during a one-dimensional unsteady heatconduction process, using thermal equilibrium method to establish the difference equationfor each node, introducing functional and sensitivity coefficient, optimize the initialboundary conditions through the Newton iterative method, realize the calculation processusing Matlab programming, and verify the accuracy of the algorithm for the inverse heatconduction problem, the calculate relative error is9.03×10-12.We described the essential feature of the heat conduction process in spray coolingprocess, the experimental results showed that the heat flux on the surface changed with thetime, the trend was increase-decrease-increase-decrease, in the jet impact zone widthdirection it increased on the first, then decreased. There was an black region after the coolingstarting, when the temperature of surface was about960℃,the region was covered with theblack region, the cooling process got into the fast cooling phase; Along with the increase offlow density, Leidenfrost temperature increased obviously, as the water density increasedfrom3.9to6.3, Leidenfrost temperature increased from797℃to921℃; Stable state film boiling stage in the jet impact area appeared before the qmax, and it appeared after the qmaxoutof the jet impact area.