Design And Realization Of Automatic Control System For Helium Circuit Pressure In Large-Scale Commercial Hydrogen Liquefaction Plant

In order to solve the problems of high complexity in operation of the helium compressor in the hydrogen liquefaction system during the startup phase, response delay in variable condition control, and poor system stability, an automatic helium circuit pressure control system for large-scale commercial hydrogen liquefaction plant was designed. The fuzzy self-tuning PID with split-range control algorithm is used to realize automatic pressure adjustment of the high and low pressure sides of the compressor. The adaptive adjustment mechanism of the valve switching rate based on the deviation change rate is introduced to achieve stable control of the pressure during system loading, cooling and shutdown processes. The application results show that the system is simple to handle and effectively reduces the dependence on personnel operating experience. The system pressure regulation is real-time and stable, and proves to be of significant value in engineering practice.