Development of Molten Salt Electric Heating Control System Based on Monitor and Control Generated System and Programmable Logic Controller

Abstract

Molten salt has important applications in renewable energy power generation and energy storage heating system as the heat transfer and storage working fluid. As the constant power heating can easily lead to the burning of electric heater and the decomposition of molten salt, a constant temperature electric heating system is needed for melting and anti-freezing of molten salt system. We used monitor and control generated system (MCGS) configuration software and SIEMENS S7-200PLC, combined with solid-state relay (SSR), thermal resistance and electric heater, to design a closed-loop electric heater temperature PI control system. According to different PI tuning methods for experimental comparison, the contradiction problems of the PI controller over-tuning and anti-interference were solved by adding anti-integral saturation and two-degrees-of-freedom control. While the over-tuning was greatly reduced, the anti-interference function of the temperature of molten salt heat storage system under the interference condition was realized, and the temperature control of molten salt heat storage electric heater was carried out.

Keywords

• solar energy utilization
• heat storage of molten salt
• monitor and control generated system (mcgs)
• programmable logic controller (plc)
• temperature control
• pi control