Mars colony: water piping

[Dominatus]

There are many plans for colonizing Mars, by many different groups. I can't help but wonder how water would be piped between different modules. Is there some way to insulate the pipes enough so that the extremely cold winter conditions wouldn't freeze the liquid water in the pipes? I think burying the piping would be the best plan, since that's what we do on earth. Permafrost would make it difficult, so let's say that option is out. How might this work?

[Brotoro]

Burying is good. And if you will not allow digging in the ground to do so, then just lay the pipes on the ground and cover them with dirt when we cover all the habitat modules with dirt. But mainly, constantly circulate hot water through the pipe loop, from the nuclear reactor to all the hab modules and back as the basic heating system. Tap water out of the loop at each module as needed for use.

[Ralathon]

Defrosting pipes is childs play compared to actually setting up a mars base

Anyway, you have to realize there is very little atmosphere on Mars, so you'd lose very little heat to convection etc. So your water will cool very slowly. You could just slowly circulate it around the base and use it as coolant for other systems and that should keep it liquid.

[Nuke]

i live in alaska (which seems to be the tropics lately) and wherever you have an exposed pipe you usually have to put a heat tape on it. which is just a small low power heater that has one job, keep the pipe from freezing. combined with insulation they are super effective. but given the thin atmosphere the heat transfer characteristics (and correct me if im wrong) would probibly make it hard to disperse waste heat into the atmosphere. so you could probibly just have a heat exchanger on the pipes to dump the waste heat into whatever you are moving over the pipe. this would serve double duty of getting rid of waste heat and keeping pipes from freezing.

[lajoswinkler]

Coolants eventually get contaminated by bacteria like iron bacteria and fungi.

What you need is good insulation (not a problem) and countercurrent exchange of heat. It's really not a big deal. Setting up a base in the first place... That is.

http://en.wikipedia.org/wiki/Countercurrent_exchange

[Raven.]

As people have already mentioned, if you have a base set up on Mars, then preventing a pipe from freezing is child's play. We already have the technology in use in various parts of the world. We would just need to pack it, fly it, and land it (easier said than done). Also, with very little magnetosphere and no UV protection, I imagine that you can use the solar radiation to heat the pipes and to provide heat for your base occupants.

[CougarMagnum]

It wouldn't be quite as much of a problem as you might originally think. Mars is frigid, but the atmosphere is quite thin (less than 1% Earth's), which means that very little heat would be lost through conduction and convection. Most of the heat transfer would occur through radiation. As has been suggested, heat tape would probably do the trick anyway. No biggie.

[Scotius]

If you have nuclear reactor installed, keeping things warm stops being a problem.

[Raven.]

If you have nuclear reactor installed, keeping things warm stops being a problem.

In my opinion, this is probably not a good idea. Real world nuclear reactors are typically located very close to a body of water for the purposes of cooling (Fukishima for example). These reactors will pump water in from a nearby body of water of which they will then superheat; the water is instantly turned to very hot steam. If you put a reactor on Mars, you would have to have a way to cool it. There's no fluid water on Mars, meaning that you would have to mine ice in order to feed your reactor or use a much different cooling system, such as a gas system using either helium or CO2. Another thing to consider is that a cooling system merely relocates the heat. You still have to have a way to get rid of it. On earth, that means dumping water from your secondary coolant loop into a body of water. On Mars, this means radiating the heat, which not as effective.

Basically, you're right. Keeping things warm stops being a problem. But things getting way too warm becomes your new problem; it would be a martian bar-b-Que. The reactor would very quickly melt down I would imagine. The good news is that Mars is a dead planet, so if your reactor melts down and radiates the landscape you're not killing anything except yourself.

[SargeRho]

You can use large radiators on Mars, and/or use the waste heat to melt water.

[DonLorenzo]

What is perhaps an interesting question is whether burying is actually better than suspending them in the thin air, here on earth burying is a no-brainer, but perhaps the thin air changes that. I don't know.

[DerekL1963]

If you have nuclear reactor installed, keeping things warm stops being a problem.

Instead, keeping the reactor the cool becomes a problem - because the same the same thin atmosphere that slows down convection from your water pipe *also* slows down convention from any radiator system for the reactor. It's a nice problem to have, but it is a problem.

[Brotoro]

Being that nuclear reactors have been designed for use in space (where you don't have a source of cooling water available), they could also work on Mars. You just need a proper radiator system.

[Nuke]

yea, dont let the fact that we are still using first and second generation pressurized water reactors be an indication of the state of the art in nuclear technology (perhaps circa 1970, and thats being generous). were probibly going to use a liquid metal cooled reactor with radiators (like the ones flown in space by the soviets, us), and thats assuming we haven't cracked fusion before we get to mars (neither one seems to be happening any time soon).

[lajoswinkler]

In my opinion, this is probably not a good idea. Real world nuclear reactors are typically located very close to a body of water for the purposes of cooling (Fukishima for example). These reactors will pump water in from a nearby body of water of which they will then superheat; the water is instantly turned to very hot steam. If you put a reactor on Mars, you would have to have a way to cool it. There's no fluid water on Mars, meaning that you would have to mine ice in order to feed your reactor or use a much different cooling system, such as a gas system using either helium or CO2. Another thing to consider is that a cooling system merely relocates the heat. You still have to have a way to get rid of it. On earth, that means dumping water from your secondary coolant loop into a body of water. On Mars, this means radiating the heat, which not as effective.

Basically, you're right. Keeping things warm stops being a problem. But things getting way too warm becomes your new problem; it would be a martian bar-b-Que. The reactor would very quickly melt down I would imagine. The good news is that Mars is a dead planet, so if your reactor melts down and radiates the landscape you're not killing anything except yourself.

Commercial nuclear power plants usually use pressurized water reactors (PWR). That's not the stuff you'd be using in space. It's huge.

You'd use a compact reactor with highly enriched uranium, liquid alkali metal alloy coolant and radiators for cooling.

It can be done, and it was actually done. As you can see, the energy is not very high, but sufficient for a small base.

Such reactors would obviously have lots of automatic protection systems and would not be prone to steam bubbles, water attacking zirconium, hydrogen explosions and other typical stuff.

There is one problem - radiation. Such reactors aren't shielded. Lots of neutron and gamma radiation would be shining in all directions. The reactor would have to be in a hole or behind a regolith mound.

[MBobrik]

Basically, you're right. Keeping things warm stops being a problem. But things getting way too warm becomes your new problem; it would be a martian bar-b-Que. The reactor would very quickly melt down I would imagine. The good news is that Mars is a dead planet, so if your reactor melts down and radiates the landscape you're not killing anything except yourself.

Well, obviously, a reactor used to provide heating and electricity for a martian colony would be small enough to be effectively cooled by dumping the waste heat into the colony as heating. So nothing would melt down.

[Nuke]

you could also potentially use waste heat for extracting water from martian soil. you could actually dump a lot of waste heat into the ground. dig a hole and bury a cooling loop. then have a sub surface membrane capture any moisture liberated in the process.