SPACE SUIT THERMAL CONTROL USING NON-TOXIC MICROENCAPSULATEDPCM TWO-PHASE FLUID

A TWO-COMPONENT HEAT TRANSFER FLUID WHICH CONSISTS OF CAPSULES OF MICROENCAPSULATED PHASE-CHANGE MATERIAL (PCM) SUSPENDED IN WATER IS TO BE DEVELOPED FOR APPLICATION TO CLOSED SYSTEM LIQUID-COUPLED HEAT EXCHANGE WITHIN A SPACE SUIT (EMU). THE TWO-COMPONENT FLUID (SLURRY) WILL CONSIST OF APPROXIMATELY 30% BY WEIGHT OF PCM CAPSULES OF APPROXIMATELY 25 MICRONS IN DIAMETER. THE PCM WILL PROBABLYBE EITHER TETRADECANE (5.9 DEGREE(C) MELTING TEMPERATURE), OR HEXADECANE (18.2 DEGREE(") MELTING TEMPERATURE), MICROENCAPSULATED IN A POLYMER SHELL OF APPROXIMATELY 1 MICRON WALL THICKNESS. SUCH A TWO-COMPONENT FLUID HAS BEEN SHOWN TO HAVE TWICE THE HEAT TRANSFER COEFFICIENT OF WATER AND FIVE TO SIX TIMES THE THERMAL CAPACITANCE. A PCM STORAGE MODULE IS ALSO TO BE DESIGNED FOR INTEGRATING WITH THE PCM FLUID, TO FORM AN INTEGRAL PCM FLUID/STORAGE SYSTEM WHICH POTENTIALLY CAN BE USED AS A NON-TOXIC AND NONEXPENDABLE TEMPERATURE CONTROL SYSTEM FOR AN EMU (SPACE SUIT). A COMPUTER MODEL AND LABORATORY SIMULATION OFSUCH A SYSTEM IS TO BE DEVELOPED. SUCH A SYSTEM IS POTENTIALLY CAPABLE OF IMPROVING EFFECTIVENESS AND CAPACITY OF AN EMU WHILE MINIMIZING SPACE RADIATOR SIZE AND PUMPING REQUIREMENTS.