I wanna steampunk society. Eco friendly and uber cool.

[Twilight Hue]

I'll start with a car.

What else should we add?

 

[The Hammer]

Zeppelins

 

[Stevicus]

 

[Twilight Hue]

Now we are gaining steam! *grin*

 

[JustGeorge]

https://www.foodnetwork.com/recipes/alton-brown/vegetarian-steamed-dumplings-recipe-1942919

Steam without dumplings would be a waste.

 

[Heyo]

I want a big Stanford torus space station. The most efficient method of power generation on such a station would be a steam engine.

 

[exchemist]

I want a big Stanford torus space station. The most efficient method of power generation on such a station would be a steam engine.

That's interesting. I had never thought of a steam engine in space but now that you mention it I can see that a closed cycle steam engine might work quite well - though I suppose one would need precautions against the radiator side freezing and splitting, if it were ever switched off.

 

[exchemist]

Zeppelins

View attachment 48119

Who is Airbus Dumbledore?

 

[Altfish]

I've accidently wandered into their conventions in Whitby and Haworth; great fun.

 

[Samael_Khan]

I'll start with a car.

What else should we add?

I am actually looking into WW1 vehicles at the moment. That era was very steampunk. Lots of experimental units even. Zeppelins, weird tanks etc.

 

[Subduction Zone]

Since this is an online forum we need a way to log on:

 

[exchemist]

I recommend the Kew Bridge steam museum (once we get out of lockdown) for anyone living in or visiting London. I was once able to arrange a joint birthday party for my son and some friends there, when they were little, but it is very interesting for adults with a technical interest in old steam machines:

 

[Heyo]

That's interesting. I had never thought of a steam engine in space but now that you mention it I can see that a closed cycle steam engine might work quite well - though I suppose one would need precautions against the radiator side freezing and splitting, if it were ever switched off.

Space is ideal for steam engines. You have a 6000 K source on one side and a 4 K sink on the other. With that gradient and the efficiency of a modern turbine you have near unlimited power. The radiation would have to be staggered anyway so freezing is less of a problem. The only reason the ISS relies on low efficiency photo voltaic is that turbines and water are heavy and therefore prohibitive expensive to bring into orbit.

 

[exchemist]

Space is ideal for steam engines. You have a 6000 K source on one side and a 4 K sink on the other. With that gradient and the efficiency of a modern turbine you have near unlimited power. The radiation would have to be staggered anyway so freezing is less of a problem. The only reason the ISS relies on low efficiency photo voltaic is that turbines and water are heavy and therefore prohibitive expensive to bring into orbit.

What do you mean by the radiation being "staggered" and how would you avoid freezing on the cold side?

 

[Heyo]

What do you mean by the radiation being "staggered" and how would you avoid freezing on the cold side?

You need multiple stages of heat exchange with liquids ranging from helium to water or maybe even sodium to use the full temperature gradient.

 

[Subduction Zone]

Space is ideal for steam engines. You have a 6000 K source on one side and a 4 K sink on the other. With that gradient and the efficiency of a modern turbine you have near unlimited power. The radiation would have to be staggered anyway so freezing is less of a problem. The only reason the ISS relies on low efficiency photo voltaic is that turbines and water are heavy and therefore prohibitive expensive to bring into orbit.

Radiating heat might be a big problem. In space radiation is the only reasonable way to get rid of heat. One could vent steam, but that is incredibly expensive since one has to bring water up to the station. And the temperature differences are not that great. Temperature in direct sunlight is about 300 C and just 4 K in the shade. A difference of about 560 degrees (C or K). The problem is that the shaded side radiates directly tied to the object's temperature. How hot is your steam going to be? It will be quite a bit cooler than the 565K direct Sunlight temperature to start with and in doing work will lose quite a bit more heat. You would need a huge surface area to radiate off the heat and keeping that in the shade would be troublesome.

 

[Heyo]

Radiating heat might be a big problem. In space radiation is the only reasonable way to get rid of heat. One could vent steam, but that is incredibly expensive since one has to bring water up to the station. And the temperature differences are not that great. Temperature in direct sunlight is about 300 C and just 4 K in the shade. A difference of about 560 degrees (C or K). The problem is that the shaded side radiates directly tied to the object's temperature. How hot is your steam going to be? It will be quite a bit cooler than the 565K direct Sunlight temperature to start with and in doing work will lose quite a bit more heat. You would need a huge surface area to radiate off the heat and keeping that in the shade would be troublesome.

The sun is about 6000 K, not 600. When you have mirrors on the sunlit side focussing on a point on the axis, you can harvest those 6000 K. At the same time you keep the "south" side of the axis in constant shade.

 

[exchemist]

You need multiple stages of heat exchange with liquids ranging from helium to water or maybe even sodium to use the full temperature gradient.

But you can't use most of these as viable working fluids in a heat engine, can you? Has anyone built a sodium vapour engine? A helium engine?

I assume by a steam engine you mean water/steam is the working fluid. You can certainly superheat the steam, to supercritical temperatures if you want, though the pressures will necessitate a lot of heavy metal. That gives you a T1 of 600C or so. T2 will also need to be high enough to get an acceptable rate of heat rejection from the radiator, as @Subduction Zone points out.

Has anyone done the sums on all this?

 

[Heyo]

But you can't use most of these as viable working fluids in a heat engine, can you? Has anyone built a sodium vapour engine? A helium engine?

I assume by a steam engine you mean water/steam is the working fluid. You can certainly superheat the steam, to supercritical temperatures if you want, though the pressures will necessitate a lot of heavy metal. That gives you a T1 of 600C or so. T2 will also need to be high enough to get an acceptable rate of heat rejection from the radiator, as @Subduction Zone points out.

Has anyone done the sums on all this?

I have done some back-of-the-envelope calculation when I first thought about it and even in the simplest form (water-steam, 0 to 200 C) it is still more effective than the best photo diodes that were available at that time.

 

[Subduction Zone]

The sun is about 6000 K, not 600. When you have mirrors on the sunlit side focussing on a point on the axis, you can harvest those 6000 K. At the same time you keep the "south" side of the axis in constant shade.

You misunderstood. Yes, the Sun is about 6,000 K, at the surface. The temperature of its radiation by the time it gets to Earth is far less. Mirrors can concentrate some of that heat, but radiating it is going to be an engineering nightmare.