Session: 15-01-01: ASME International Undergraduate Research and Design Exposition

Paper Number: 150580

150580 - Bench-Scale Heat Pipe and Vapor Chamber Testing for Space Applications 

NASA’s space missions demand better and more efficient life support systems, particularly involving the removal of carbon dioxide from air. The current state-of-the-art carbon dioxide removal systems use pellet adsorption beds; however, in improving this design, two challenges present themselves: power minimization and uniform heating for carbon dioxide desorption. As a result, heat pipes and vapor chambers were found to be a good candidate for solving both of these problems because of their passive heating nature and capability of direct implementation into these adsorbent beds. The state-of-the-art heat pipes used terrestrially are copper-water heat pipes for various applications, such as computer heat management. However, these can only operate up to 60 degrees Celsius, which does not meet our demands, as adsorbent beds regenerate at 200 degrees Celsius. Therefore, to reduce mass, titanium heat pipes and vapor chambers were considered because of their ability to withstand the high pressures of vaporized water while also reaching the required temperatures for bed desorption. This research work compares different titanium heat pipes and vapor chambers. Our focus was on thermal conductivity measurement, where a copper bar was used as a baseline. With the linear heat conduction equation derived from Fourier’s Law, each system measured the heat energy input into one end of the copper and measured the temperature gradient across the bar. Boiling water was used as the heat input on the first setup, where the bar was partially inserted into the water and measured for the rise in temperature across the length. The second setup used an electric fabric heater to produce a temperature gradient across the bar while connected to a power meter to measure its power input. Lastly, we used heated air from a heat gun to warm up one end of the bar with the other end submerged in water, measuring heat input with the change in the temperature of the water. The results from the testing of the copper bar were used to determine which test apparatus was the most accurate and efficient at finding the thermal conductivity constants. Looking forward, the titanium heat pipes and vapor chambers will be tested with the best setup to approximate their thermal conductance. We expect the thermal conductivity constants of the titanium heat pipes and vapor chambers to be significantly larger than that of copper. The findings of this research will contribute to the continuous development of efficient heating methods for carbon dioxide adsorption beds used in space applications.

Presenting Author: Jorge Pombo Florida International University

Presenting Author Biography: My name is Jorge Pombo and I am currently a rising junior undergraduate student at Florida International University. Born and raised in Miami, Florida, space exploration has been the one passion I've consistently had from a very young age. That dream of becoming an astronaut as a kid is still stuck with me today as an adult because of my fascination for the unknown above us. My academic pursuits have been molded around this passion of mine, where I aspire to work in the aerospace field down the line. My current research interests include robotics, combustion and propulsion systems, thermal analysis and heat transfer, and astrodynamics.

Authors:

Jorge Pombo Florida International University
Tra-My Justine Richardson NASA Ames Research Center