Research on variable condition control of power systems with large delay characteristics

A variable operating condition control strategy based on a combination of open-loop and closed-loop is proposed to address the challenge of variable operating condition control for Li/SF6 closed cycle power systems containing immersed combustion boiler reactors with large delay characteristics. This article establishes dynamic models of submerged combustion boiler reactors, spiral tube evaporators, turbines, shell and tube condensers, and liquid collectors. The one-dimensional distributed parameter model of spiral tube evaporators and the concentrated parameter model of submerged combustion boiler reactors are respectively verified, and the accuracy of the models is verified. Two SF6 flow regulation methods were proposed, namely step regulation and slope regulation, and simulations were conducted to analyze the variation patterns of working fluid temperature, flow rate and pressure at the evaporator outlet, boiler reactor temperature, and pump water supply flow parameters during variable operating conditions. The results showed that during the variable operating conditions of the system, the changes in various parameters were stable; Under the same turbine speed regulation amplitude, slope regulation of SF6 flow rate reduces the time consumption of the variable operating condition process compared to step regulation. The research results can provide theoretical reference for the design of power systems for future underwater vehicles.