Habitation 2006 Thermal Textiles

Space Suit Applications of Thermally Conductive Textiles and Plastics : 

Space Suit Applications of Thermally Conductive Textiles and Plastics HABITATION 2006 February 5-8 Gregory Quinn, Hamilton Sundstrand Felipe Chibante, NanoTex Corp.

Overview: 

Overview State of development of carbon nanotube filled plastics & fibers LCVG thermal resistance network Benefits of thermally conductive plastics & fibers to the LCVG Benefits of thermally conductive fibers to an advanced suit concept

Plastic Tubing with Carbon Nanotubes: SEM Images: 

Plastic Tubing with Carbon Nanotubes: SEM Images Vapor grown carbon nanotube protruding out of the cut surface End-view of plastic tubing with carbon nanotubes

Plastic Tubing with Carbon Nanotubes: Conductivity: 

NanoTex can fill plastics with 20% vapor grown carbon nanotubes Bulk thermal conductivity of plastic is doubled 0.268 W/m*K vs 0.535 W/m*K Tests conducted with NanoTex tubing in an LCVG configuration show a 24% improvement in overall effectiveness of the LCVG vs. unfilled tubing Plastic Tubing with Carbon Nanotubes: Conductivity

Plastic Tubing with Carbon Nanotubes: Mechanical Properties: 

Nylon and Lycra fibers have been made using vapor grown carbon nanotubes Filled plastic and fibers are stiffer than unfilled materials Tensile Test of CNT filled tubing Tensile Test of unfilled tubing (Both graphs are at the same scale) Plastic Tubing with Carbon Nanotubes: Mechanical Properties

Slide6: 

Filled tubing with filled fabric Normal tubing with normal fabric Loop Pull of Carbon Nano Tube Filled Tubing Loop Pull of Unfilled Tubing CNT Composite Fibers and Plastics

LCVG Thermal Resistance Network: 

LCVG Thermal Resistance Network Tubing Comfort Layer Skin Water Water Temperature Tubing Temp. Comfort Layer Temp. Skin Temp. Comfort R. Tubing R. Convection Resistance Total Resistance = Rconvection+ Rtubing + Rcomfort

Slide8: 

Water Temperature Tubing Temp. Comfort Layer Temp. Skin Temp. Comfort R. Tubing R. Convection Resistance Benefits of Increased Tubing ‘k’ Tubing area could be decreased while keeping the total resistance constant Total resistance could be decreased Decreasing R allows A smaller DTlm A higher Tout A lower mass flow rate The end result is a larger design envelope for mass flow rate, tubing length and water temperatures R=L/(k*A) or R=ln(r2/r1)/(2pLk) Q=DTlm/R Q=m*Cp(Tin-Tout) Resistance Power transferred from skin Power gained by water

Slide9: 

Water Temperature Tubing Temp. Comfort Layer Temp. Skin Temp. Comfort R. Tubing R. Convection Resistance Increasing Comfort Layer ‘k’: Heat Spreading Also decreases total resistance Adds thermal paths to a larger skin area Decreased reliance on the body to spread heat resulting in decreased variations in local skin temperature End result is fewer cold spots and more comfortable, effective LCVG

Slide10: 

Increasing Fabric ‘k’: Distributed Thermoelectric Heat Pumps Thermoelectric heat pumps will eventually be small and efficient enough to act as distributed heat pumps in a spacesuit Heat spreading layers are needed to move heat to and from the small, point devices Heat pumped out of the suit Heat Spreading Layer Heat Spreading Layer

Slide11: 

Cascading Benefits Smaller radiator Smaller pump Less cold spots Fewer tubes in an LCVG Possibility of distributed heat pumps Overall larger design envelope for suit thermal management system