| Large-scale vertical quench furnace is critical equipment for thermal treatment of aluminum alloy components what widely used in aerospace industry. such as the end collar of rocket、missile landing chassis、torpedo shell and so on.The required temperature of high-performance aluminum alloy is very harsh in quench insulation stage, which should control temperature of aluminum alloy in a specific range and keep aluminum alloy in high homogeneity. The structure of large-scale vertical quench furnace is very complex. Many different types of heat transfer are combined and temperature distribution is parameter characteristically. Thus, it is difficult to get the homogeneity of quench temperature precisely.To solve the above problem, the specific work of this paper is constructed as follows:(1) The feature of quench furnace in quench insulation stage is analyzed and the temperature is estimated based on the principles of the heat balance. Then, the gridding order thermal radiation between workroom and forgings is built as boundary conditions. The temperature of aluminum alloy forgings can be estimated according to different thermal conductivity and radius.(2) Reasonable assumptions are utilized to simplify the model of the furnace. Then wavelet is used to transfer the partial differential equation describing distributed parameter system control model to matrix algebra equation based on establishing large vertical quench furnace temperature dynamic model of Second-order distributed parameter systems. Experiment data prove that it acquired accurate identification effect by the method.(3) Simulation experiments are carried on by MATLAB based on wavelet transform parameter identification. Through simulation results, characteristic of influence on parameter identification is analyzed by space step and noise, which proves that the method is effective and exact. Thus, it can be applied to the large-scale vertical quench furnace parameter Identification. |
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