Dynamic flow optimization for a three-loop fluid heat dissipation system in spacecraft

Abstract

Dynamic optimization of the fluid loop is critical for the active thermal control system (ATCS) for future spacecraft. In this paper, the dynamic heat transfer model of a three-loop fluid heat dissipation system is constructed by the transient heat current modeling method to analyze the optimal control problem of dynamic flow allocation. A sequential quadratic programming (SQP) algorithm combined with the exact external penalty function method is designed to solve the difficulty of temperature path constraints. Simulation results show that the proposed method effectively improves the optimization effect of temperature path constraints and significantly reduces the computational time. Compared with the results of mean allocation flow (unoptimized) and steady flow optimization, the dynamic flow allocation reduced the residual heat by 6.9% and 21.5%, respectively, while meeting all the temperature constraints. In addition, the total flow rate needs to be increased at least by 48% to meet all temperature constraints and achieve similar heat dissipation capacity, when the flow allocation was designed as steady variables. The comparison results indicate that the dynamic flow allocation effectively improves the heat dissipation efficiency of the parallel fluid loop system and ensures the payload temperatures within the constraints.