Model free control law in the production of chemical fertilizer

The pH value control of neutrality process of ammonium nitrate product has a great influence on the quality of the production.But it is always difficult to control the pH value in producing ammonium nitrate,because it is a strong non-linear and large-scale time-delay process.In the process of synthetic ammonia production,nearly all the synthetic ammonia equipments have got the problem with the control of the ratio between hydrogen and nitrogen.The system of ratio for hydrogen and nitrogen is a super large-scale time-delay system,it is impossible for PID controller to make this closed-loop control process stable.But by the model free control law's powerful controlled function,the above two processes can be stably closed-loop controlled.The paper analyzes and introduces its successful applications to the two processes.