A fuzzy coordination control of a water membrane evaporator cooling system for aerospace electronics

Abstract

A safe and reliable thermal control strategy is of great significance for the cooling of aerospace electronics in deep space exploration. How to run efficiently and reliably when a thermal control system is faced with increasingly complex thermal conditions and limited cooling capacity makes the optimization of control strategy more and more important. This paper presents a new fuzzy coordination control (FCC) strategy for the water membrane evaporator (WME) cooling system composed of the liquid cooling and ventilation garment (LCVG), the cold plate, and the WME. A 3-node thermodynamic model of the WME cooling system was established, in which the WME thermal model considered heat and mass transfer across the membrane. The FCC is proposed to coordinate two separate controllers to balance the two inputs, one regulating the flow of the pump and the other regulating the opening of the three-way valve. Numerical results suggest that the FCC can avoid the reliability reduction caused by only using valve control, due to the limited valve opening range. When the step of the cold plate thermal load increases by 40%, the FCC's setting time is 75.4% of the control pump alone, but the FCC only needs 92.2% of the pump flow; The FCC's overshoot is 50% of the control valve alone, but the FCC only needs 76% of the valve opening. Thus, the FCC has the advantages of less overshoot, less oscillation period, and save energy.