Modular double brazed phase-change material heat exchanger
A phase change material (PCM) heat exchanger system for a rocket or other spacecraft is described. The PCM heat exchanger utilizes phase-change material to store heat absorbed from a hot working fluid. The PCM heat exchanger may be configured as an integrated modular double brazed layout that includes folded fins to distribute heat from a working fluid (e.g., hydraulic fluid) to PCM. A modular configuration may enable a heat exchanger system to be scaled up or down by adding or removing modules to meet cooling requirements for particular rockets and their flights.
1 . A heat exchanger system for a rocket, the heat exchanger system comprising:
a heat exchange component configured to carry a working fluid;
a first phase change material (PCM) component comprising PCM, wherein the first PCM component is in thermal contact with a first side of the heat exchange component;
a second PCM component comprising PCM, wherein the second PCM component is in thermal contact with a second side, opposite the first side, of the heat exchange component, and wherein the first PCM component, the heat exchange component, and the second PCM component are mutually interconnected by double brazing; and
a working-fluid supply system configured to selectively provide the working fluid to the heat exchange component to alternately heat and cool the first and the second PCM components depending on an operating state of the rocket, such that the working fluid is i) hotter than the melting temperature of the PCM during flight of the rocket and ii) colder than the melting temperature of the PCM when the rocket is stationary on a launch pad for the rocket.
2 . The heat exchanger system of claim 1 , wherein the PCM component comprises a support matrix having a network of cavities at least partially filled with the PCM.
3 . The heat exchanger system of claim 2 , wherein the support matrix has a honeycomb structure.
4 . The heat exchanger system of claim 2 , wherein the support matrix is a lanced offset fin structure.
5 . The heat exchanger system of claim 1 , wherein the working fluid is a hydraulic oil.
6 . The heat exchanger system of claim 1 , wherein the working fluid sup-ply system comprises valves that operate to select either the working fluid that is hotter than the melting temperature of the PCM or the working fluid that is colder than the melting temperature of the PCM.
7 . The heat exchanger system of claim 6 , wherein the selection by the valves is based, at least in part, on a determination of location of the rocket.
8 . The heat exchanger system of claim 1 , further comprising lanced offset heat fins between the heat exchange component and the PCM component.
9 . The heat exchanger system of claim 1 , wherein the heat exchange com-ponent comprises serpentine-shaped chambers to carry the working fluid.
10 . A method of operating a heat exchanger in a rocket, the method comprising:
conveying working fluid through a heat exchange component that is in thermal contact with a phase change material (PCM) component comprising PCM; and
selectively providing the working fluid to the heat exchange component to alternately heat and cool the PCM component depending on an operating state of the rocket, such that the working fluid is i) hotter than the melting temperature of the PCM during flight of the rocket and ii) colder than the melting temperature of the PCM when the rocket is stationary on a launch pad for the rocket, wherein the working fluid supply system comprises valves that are configured to operate to select either the working fluid that is hotter than the melting temperature of the PCM or the working fluid that is colder than the melting temperature of the PCM, and wherein the selection by the valves is based, at least in part, on a determination of location of the rocket and a determined phase of the PCM.
11 . The method of claim 10 , wherein the PCM component comprises a lanced offset fin structure having a network of cavities at least partially filled with the PCM.
12 . The method of claim 10 , further comprising:
measuring a temperature difference between the working fluid entering the heat exchange component and the working fluid exiting the heat exchange component; and
determining, based on the measured temperature difference, a phase of the PCM.
13 . The method of claim 12 , further comprising selecting, based at least in part on the determined phase, either the working fluid that is hotter than the melting temperature of the PCM or the working fluid that is colder than the melting temperature of the PCM.