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Essentially, I am trying to design a heat exchanger for a space suit traveling to mars. From my understanding, I assumed that the energy generated from the space suit relates to the astronaut as well as the electrical components. In addition, by comparing the atmosphere of mars to earth, I considered convection to be negligible. As well as the radiation that would be absorbed from the sun since the suit is white and reflective.

And that the only way energy is leaving the suit is by radiation emitted from the heat exchanger. In order to improve the current system, my aim is to make the cooling system lighter and more compact. I chose to design a cross-flow heat exchanger for this reason. From my understanding, it is important to choose a material with high thermal conductivity for efficient heat transfer. I was thinking of aluminum alloys due to its properties, along with water as the coolant.

Now if I want to maintain the inside of the suit as body temperature, I am sort of lost as to what my conditions would be. I know I want to maintain body temperature within the suit, but I am not too sure about my inlet/outlet temperatures, and flow. Should I consider other parameters or heat exchangers as well, and if so, why?

peterh
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Rye
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    Related https://space.stackexchange.com/questions/16901/will-suits-worn-on-mars-lose-kilograms-of-expendable-water-each-time-they-are – Steve Linton Dec 03 '19 at 09:23
  • Your clarification in comments are excellent! I've moved them back to your original question and you can probably just delete them (I've deleted mine). Please feel free to edit further, or you can even roll back, but I think it looks much better now! – uhoh Dec 03 '19 at 12:58
  • If you are neglecting any heat transfer due to the Martian atmosphere, you are essentially designing a suit for vacuum. In that case, it is unlikely that you wll be able to design a radiator small enough to be practical for a suit. You will need a sublimator or boiler. As the designers of current vacuum suits did. – Organic Marble Dec 03 '19 at 13:46
  • I wouldn't write off convection completely. The atmosphere may be very thin but it's also cold. A high-surface area heat sink and some fans would have a non-negligible impact – Dragongeek Dec 03 '19 at 13:46
  • I wouldn't either but that is "given" in the problem. – Organic Marble Dec 03 '19 at 14:05
  • I have considered that as well. However, would that change my heat exchanger choice significantly? I have considered other heat exchangers as well, from what i have found concentric tube, shell and tube heat exchangers are usually utilized usually on a large scale. So based on this, cross-flow and compact heat exchangers seemed to be most optimal for the design goals. Any advice on possibly scrapping the current suit design and using heat transfer relations to create a new heat exchange system? Looking for articles/links too, information is sort of tedious to find. Thanks in advance. – Rye Dec 03 '19 at 14:56
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    Sounds like you are looking for a tutorial on how to set up coolant loops and heat exchangers which is really too broad of a question. If you can show what calcs you have done so far I could retract vote. – Organic Marble Dec 03 '19 at 16:13
  • "And that the only way energy is leaving the suit is by radiation emitted from the heat exchanger." No, there is another way, the evaporation of water. The suits used on the Moon were cooled by evaporation of water using a sublimation plate. – Uwe Dec 03 '19 at 21:51
  • There's 3 close votes (not sure you can see at the moment). The category reads: "Too broad Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question." You can ask many question in Stack Exchange and in this case it's probably a good idea to break this one up into two or three that can be answered independently. Perhaps narrow this one down and put the remainder in 1 or 2 others. – uhoh Dec 04 '19 at 04:31
  • The fact that you have both 4 up votes and 3 close votes suggests that the type of the question and subject matter is welcomed, but as currently written it's too broad to cover with a single Stack Exchange answer. – uhoh Dec 04 '19 at 04:32
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    I understand. Thank you to everyone who took time out of their days to take a look. I really appreciate it. This is my first time using this website, and I will definitely consider the way I word my questions in the future. I am a student and I'm stressed out, and I can't seem to get past this question. Hopefully I get around to understanding it. Thanks again. – Rye Dec 04 '19 at 07:14

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