Surfactant Based Boiling System For Zero Gravity Applications Md. Qaisar Raza, Nirbhay Kumar, Rishi Raj Thermal and Fluid Transport Laboratory Department of Mechanical Engineering, IIT Patna ABSTRACT METHODOLOGY CONCLUSIONS REFERENCES MOTIVATION Boiling is widely used in earth gravity • in various energy systems • for heating and cooling Comparison of HTC (Mudawar 2001) Thermal management is becoming a challenge in electronics and energy systems POOL BOILING Heated surface is completely submerged in a pool of liquid Utilizes latent heat of vaporization to dissipate large heat flux within small temperature difference INTRODUCTION WHY BOILING IN ZERO-G? Thermal management of space-based infrastructure for longer duration microgravity and planetary missions • space station, astronaut’s suit • rocket, satellite • cryogenic fuel storage etc. At zero-g buoyancy becomes less dominant Bubbles coalesce together → large dry out area → low CHF and HTC External stimuli for bubble removal makes the system bulky and energy intensive CHALLENGES BUBBLE BEHAVIOR Surfactants DTAB SDS Formulae CH 3 (CH 2 ) 11 N(CH 3 ) 3 Br C 12 H 25 SO 4 Na Ionic Nature Cationic Anionic Form White powder White powder MW 308.34 288.3 CMC ~ 4600 ppm ~ 2500 ppm Surfactants Triton-X100 Tween 80 Formulae C 4 H 21 (OCH 2 CH 2 ) 9-10 OH C 64 H 124 O 26 Ionic Nature Non-ionic Non-ionic Form Clear Liquid Liquid MW 624 1310 CMC ~ 200 ppm ~ 15 ppm RESULTS Present Work Downward heater Microgravity h max ~ 36 kW/m 2 -K ~ 19 kW/m 2 -K (Guo et al. 1992) ~ 7 kW/m 2 -K (Zell et al. 1989) CHF ~ 500 kW/m 2 ~ 340 kW/m 2 (Su et al. 2008) ~ 229 kW/m 2 (FC72) (Kim et al. 2002) ~ 125 kW/m 2 (Water) (Oka et al. 1995) More than 6000 fps images are acquired to elucidate the bubble departure HTC and CHF enhancement are ~2.4 and ~2.5 times, respectively, compared to pure water Great potential for zero gravity applications Preparing to perform experiment in zero gravity condition EXPERIMENTAL SETUP Mudawar I. Components and Packaging Technologies, IEEE Transactions, 2001, 24, 122-141 Raj, R; Kim. J; Mc Quillen, J. Journal of Heat Transfer, 2009, 131, 091502-1. Guo, Z; El-Genk, M. S. International Journal of Heat and Mass Transfer,1992, 35(9), 2109-2117. Zell, M; Straub, J; Weinzierl A. Physico Chemical Hydrodynamics, 1989, 11, 813-823. Su, G. H; Wu, Y. W; Sugiyama, K. International Journal of Multiphase Flow, 2008, 34(11), 1058-1066. Kim, J; Benton, J. F. International Journal of Heat and Fluid Flow, 23, 2002, 497–508. Oka, T; Abe, Y; Mori, Y. H; Nagashima, A. Transactions of the ASME, 1995, 117, 408-417. Boiling heat transfer is very efficient mode of heat transfer • Primarily governed by bubble departure which relies on buoyancy/gravity Advantage of boiling is lost in space • No buoyancy → bubble departure absent → heat transfer deteriorates Zero gravity experiments are rare and expensive Inverted heater configuration to mimic zero gravity like situation • Bubble do not depart like zero gravity A novel surfactant induced bubble departure is demonstrated against the buoyancy Bubble departure frequency of the order of ~15Hz under inverted heater is obtained More than 100% enhancement in heat transfer performance Bubble under downward facing heater behave similar to zero gravity Aqueous surfactant solution with concentration at CMC is used Triton X-100 DTAB SDS Tween-80 DI Water Triton X-100 DTAB SDS Tween-80 f (Hz) 18 12 6 0 100 200 300 400 500 q” (kW/m 2 ) q” (kW/m 2 ) 600 500 400 300 200 100 0 0 4 8 12 16 20 ΔT sup (°C) ΔT sub = 50°C ΔT sub = 50°C Steam power plant Courtesy: TEPCO, LENOVO AC Systems Lenovo laptop Sony Xperia Z5 Heat Pipe ACKNOWLEDGEMENT Dr. V. S. Jasvanth, Dr. Amrit Ambirajan and Dr. Abhijit A. Adoni, ISAC ISRO (Project No. ISRO/RES/3/674/2014-15) 400 300 200 100 4 10 -2 10 -1 10 0 10 1 q” (kW/m 2 ) Surface tension dominated regime Buoyancy dominated regime a/g Raj et al. (2009) Bottom View Time lapse Image Triton X-100 DTAB SDS Tween-80 DI Water ~ 110 kW/m 2 ~ 200 kW/m 2 ~ 380 kW/m 2 ~ 500 kW/m 2 Sideways departed bubble (ΔT sub = 50°C) DTAB ~ 200 kW/m 2 0ms 20ms 48ms 64ms 82ms Wet patches HEAT TRANSFER PERFORMANCE Insulation Dry Patch Heater Vapor A TF