Application and Study on Heat Transfer Model for Continuous 82B Billet Casting
The centerline segregation in the 82B steel billet reduces seriously the final product quality; it is closely related to the unreasonable secondary cooling water system. This paper has established a two-dimensional non-steady-state heat transfer model for the continuous 82B billet casting process, and optimized the existing secondary cooling water scheme, The results show that: the strand surface temperature falling rate is lower than the center temperature falling rate in the original cooling water scheme; it is necessary to add an additional cooling subzone after the fourth subzone for decreasing centerline segregation; the optimal cooling water scheme is that cooling intensity of the fifth subzone is increased by 150% compared with the original fourth subzone.
Study on Influences of Physical Property Parameters on Model Calculation Results of Heat Transfer in the Continuous Casting Mold
This research had developed a two-dimensional non-steady state heat transfer mode with the actual condition of a billet continuous caster.The influences of thermal conductivity coefficient,specific heat and density on the calculation results of the heat transfer model were studied.The calculation results showed that the billet surface center temperature increased with increasing of the thermal conductivity coefficient,while the billet center temperature decreased;the billet temperature increased with increasing of the specific heat and density,these were related to the influences of the thermal conductivity coefficient,specific heat and density on the accumulation and release of heat in the billet.In consideration of influence level of the thermal conductivity,density,specific heat on the model calculation results,the influence of thermal conductivity coefficient was the largest;the specific heat the second,the density relatively small.
ANALYSIS OF BOLT′S ANCHORING QUALITY BASED ON WAVELET NEURAL NETWORK
The dynamic response of bolt achieved by impact-echo method can be effected easily by some factors.It′s difficult to classify bolt′s anchoring quality according to the dynamic response of bolt.In this paper,a new analytical method of bolt′s dynamic response is put forward.The new analytical method combing with advantages of wavelet analysis and artificial neural network is presented.Firstly,the dynamic response of bolt by numerical simulation software FLAC3D is obtained.Secondlyt,he features are extracted from the dynamic response of bolt by wavelet analysis.Thirdlyt,hese features are fed into the artificial neural network for training.Finallyt,his artificial neural network to classify the bolt′s anchoring quality intelligent according to the dynamic response of bolt is employed.In order to validate this new analytical method,some practical signals of bolt′s dynamic response are used for the test.The results indicate that the new analytical method is practicable.