Temperature and humidity decoupling control based on diagonal matrix and information entropy for spinning air-conditioning

• Mathematical models of the spinning air-conditioning system incorporating spray chamber. • Decoupling control of the temperature and humidity based on information entropy. • Implementation of the dedicated control strategy using dual-loop PI controllers. • An entropy index for quantitative evaluation of the control performance. Spray chambers are widely used in spinning air-conditioning systems to humidify air. However, the cooling and humidification air treatment leads to the mutual interference between the temperature and humidity control. Moreover, the traditional PI control based on passive set-point tracking tends to cause oscillations in both variables. Therefore, based on mathematical models of the spinning air-conditioning system, decouplers for temperature and humidity control loops are designed using the diagonal matrix decoupling method. This decoupling method incorporates information entropy theory to enhance the performance of the temperature and humidity control. An entropy index-based evaluation method is proposed to assess the control performance of the air-conditioning temperature and humidity. Simulation studies on the decoupling control algorithm, integrated with the proposed automatic control strategy, are conducted using the operational data from a spinning workshop. The results indicate that compared to the conventional proportional-integral control (CPIC) method, the diagonal matrix decoupling control with information entropy (DMDCIE) completely eliminates the coupling of the temperature and humidity. It can keep the workshop temperature consistently stable at the set-point. The entropy indices of the temperature and humidity under DMDCIE are approximately 50% lower than those under CPIC, indicating that DMDCIE can significantly improve the robustness of the temperature and humidity control.