Dynamic Modeling and Predictive Control of a Steam–Molten Salt Heat Exchanger

To enhance the flexibility of coal-fired power plants (CFPPs) integrated with molten salt heat storage systems (MSHS), this study develops a dynamic modeling and predictive control framework for a steam–molten salt heat exchanger (SMSHE). A coupled dynamic model is established, capturing the heat transfer interactions among the steam side, molten salt side, and tube wall. Based on this model, a model predictive control (MPC) strategy is designed to achieve coordinated and stable regulation of both outlet temperatures. Simulation results demonstrate that the proposed MPC strategy substantially outperforms conventional proportional–integral–derivative (PID) control under various operating scenarios. The MPC strategy shortens the regulation time by 66.6% under the step change of the molten salt output temperature setpoint and reduces the rise time by 79.1% under the steam output temperature setpoint change scenario. Under the steam inlet temperature disturbance, the proposed strategy suppresses the resulting molten salt temperature deviation and accelerates its recovery by approximately 390 s. These results highlight the strategy’s effectiveness in improving temperature tracking accuracy, dynamic response, and robustness, providing theoretical and practical guidance for precise temperature control and enhanced flexibility of CFPP–MSHS integrated systems under dynamic operating conditions.