The Optimization Research Of Gas Jet Impact Disc Process Based On Predictive Control

With the development of aerospace and aviation in our country,the heat treatment process of alloy materials has become particularly important.In the quenching process,traditional oil quenching,water quenching and other methods have the disadvantages of uneven cooling,uncontrollable local cooling rate,and large residual stress.Gas quenching,with its many advantages,provides an effective quenching method.In order to guarantee the control of the metallurgical structure during the cooling process of the blanks.It is also necessary to avoid inaccurate temperature field control leading to scrapped parts.The temperature control process of the blank cooling process is particularly important.This topic is based on the principle of gas impingement heat transfer.For the distributed parameter system with the temperature field of variable thickness disc blanks,the following research was conducted on the temperature field control of the cooling process:First,based on the principle of impinging jet heat transfer,a simulation model for the blank billet quenching process was established.The variation of the billet temperature under the conditions of constant flow velocity,jet gas temperature,nozzle structure,and plate blank stationary and rotating conditions was investigated.The quenching and cooling process of the disc blank is optimized.Then,in order to achieve the temperature distribution of the cooling process of the disk and the controllable cooling rate of the key points.The inverse of the boundary conditions of the gas jet heat transfer is solved.A wavelet neural network is used to identify the jet cooling system.The genetic algorithm was used to optimize the initial value of the weights of the wavelet neural network.As a predictive model,a neural network PID controller is used as the rolling optimization scheme to design an optimized predictive control strategy for the temperature field of the heat transfer process of the disk impingement jet.With FLUENT and Simulink co-simulation,compared with the traditional PID control program.The superiority of the designed control method was verified.Finally,based on the RS-485 bus control,a control system that can change the nozzle flow rate in real time according to the set change curve is designed.And verified its reliability.Constant flow rate and variable flow rate controlled quenching experiments were performed.The key monitoring point data obtained from gas quenching experiments were analyzed.The temperature drop inside the blank was obtained.Analyze the error by comparing the simulated and measured values of the monitoring points.The maximum error in constant flow gas quenching experiments is less than 5%.The rate of temperature drop of the variable flow gas quenching experiment was eventually maintained at 1.37 K/s.The numerical simulation of the gas cooling quenching process for variable thickness billet and the reliability of the model predictive control strategy were verified.