Starship electrical system

[Drakon]

So I was thinking of the electrical system on a Beowulf, because I am weird like that, and a question occured to me.

What kind of electrical power does a ship's fusion plant produce?

I am thinking that at TL 12 to 14, fusion is acheived in a chamber, surrounded by an ultra high bandwidth "solar cell" analogous material/structure. Possibly some additional waist heat energy extraction (steam plant??).

Solar panels produce DC power, a DC current. Many of the computer systems, and electronics all run on DC. Any rotating machinery can use either AC or DC motors.

Is there a reason to include an AC power system aboard a starship?

 

[flykiller]

(steam plant??)

not on a traveller starship.

Is there a reason to include an AC power system aboard a starship?

rotary ac generation has fewer moving parts and is more reliable.

ac voltage can be stepped up/down to almost any value as needed.

ac can be three-phased, making it cheaper to build and install, and can operate with one phase grounded thus making it more robust in damage control situations.

ac is an inherent signal emitter.

if any of that is important to you/the game/something then it'll play a role. if not then not.

What kind of electrical power does a ship's fusion plant produce?

I just say dc and leave it at that. if the issue ever comes up in a game I'll know where to start winging it, but it hasn't yet.

http://www.travellerrpg.com/CotI/Discuss/showpost.php?p=517560&postcount=35

 

[aramis]

So I was thinking of the electrical system on a Beowulf, because I am weird like that, and a question occured to me.

What kind of electrical power does a ship's fusion plant produce?

I am thinking that at TL 12 to 14, fusion is acheived in a chamber, surrounded by an ultra high bandwidth "solar cell" analogous material/structure. Possibly some additional waist heat energy extraction (steam plant??).

Solar panels produce DC power, a DC current. Many of the computer systems, and electronics all run on DC. Any rotating machinery can use either AC or DC motors.

Is there a reason to include an AC power system aboard a starship?

Several reasons -

• AC suffers less distance loss (and resultant thermal addition)
• AC sets a steady unified timing signal
• AC is more easily rectified than DC inverted
• Ships are likely to be using dual nets... AC for system where it is beneficial, DC for others.

 

[Condottiere]

I've considered it, and I suspect that if an appliance can be battery powered or recharged, that's the most likely option.

Current ship design systems certainly allow options, depending on the size of the spacecraft.

The computers certainly don't need to be powered directly from the main power plant, whether or not you install surge protectors; in most cases, jump drives, manoeuvre drives, weapon systems, sensor suites, basic ship systems.

 

[The Oz]

Several reasons -

• AC suffers less distance loss (and resultant thermal addition)
• AC sets a steady unified timing signal
• AC is more easily rectified than DC inverted
• Ships are likely to be using dual nets... AC for system where it is beneficial, DC for others.

As a former Navy nuclear engineer, I can say that modern warships (and presumably commercial vessels too) use dual systems (AC and DC). The generators produce AC, and DC is rectified from it where needed.

I'm not sure about how fusion plants would create electricity. I'd probably just assumed there'd be some type of coolant that would be used in some kind of turbine generator, but I don't know.

A quick look at the ITER web site https://www.iter.org/sci/MakingitWork shows that I was right, at least for the ITER. Futuristic plants could do it differently, of course.

 

[whartung]

I would think that large ships especially would have an AC backbone, but DC "plugs".

Smaller ships may be pure DC. That is, an AC generator with DC rectified pretty much at the source and then distributed throughout the small ship.

That said, I think (I don't know) that AC is better for things like high wattage items (like ovens and the like).

There have already been musings about wiring houses with DC along with AC so we can get ride of the zillions of power supplies we all use.

I already have hard wired USB ports in my house for charging things, I can easily see the USB plug becoming a universal power connector.

Mind, my USB plugs are rectified at the plug. A DC wired house would have a central rectifier driving all of the plugs.

 

[Redcap]

My take is that a ships fusion plant produces DC which is them inverted into AC.

Here's why: At the most simple and tried (not necessarily trusted!) level, it's likely to be a PLR format of plant (Pressurised Liquid Reactor), with a turbine in the steam loop; the turbine will spin a generator col of some format, and hey presto, AC current.

In a more solid-state environment, it's much more likely that some kind of thermoelectric generation (TEG, or Seebeck) might be employed; this would be the most reliable and safe manner of power generation on board a starship, as it would not require pressurised liquids to be present on the vessel. However, a TEG produces DC, not AC, so this would have to be passed through an inverter of some form to produce AC, adding to the mass of the system.

FWIW, IMTU, a ships power plant is a TEG system.

 

[The Oz]

I would think an all-solid-state system would be more reliable and resistant to damage, but perhaps a different type of system (sodium-cooled, anyone) might be more efficient?

I've never given it much thought, but I would be inclined to handwave some high-tech solid-state system, if I needed that much detail. And a solid-state system would produce DC, I think.

 

[Redcap]

A bit OT, but related:

One of the more glaring omissions from the rules is reactor cooling components, be it massive heat sinks, radiator fins, coolant exhaust ports (and the means to refill them), and so on. Heat build up is an issue, after all.

Space Shuttles dealt with it, in major part, by opening the cargo doors towards Earth, and radiating the heat away from the shuttle.

So, I wonder, how do Traveller starships deal with it?

 

[mike wightman]

Magic heat sinks based on an application of gravitics technology is how I explain it.

 

[The Oz]

Magic heat sinks based on an application of gravitics technology is how I explain it.

Good enough for me; I can't explain it, either.

 

[MThompson016]

Hmm. Thinking back to the Ustafish, I'm thinking for power generation and distribution:
-Main generation from the powerplant as AC.
-Motor generators AC to DC for a storage battery and any DC tasks
-Motor generators for standard (50-60 Hz) AC to higher frequency AC for radars
-Selective tripping so a middle passenger plugging in his alarm clock doesn't shut down all the power on the ship.
-Offboard connection to standardized power mains when at a starport for both the standard AC and DC buses

If there's demand, I can sketch out the mimic bus, as an idea.

 

[Drakon]

Hmm. Thinking back to the Ustafish, I'm thinking for power generation and distribution:
-Main generation from the powerplant as AC.

This is what started this for me. I started thinking that if the fusion plants puts out DC instead, and most of your systems, like electronics, computers, sensors etc. are DC anyway, each with it's own AC to DC converter built in, why do you need an AC system anyway?

A Beowulf is less than 50 meters long. Is it small enough to make the need for an AC set up superfluous?

<much good stuff snipped for space.>

-Offboard connection to standardized power mains when at a starport for both the standard AC and DC buses

So, one motor generator for the shore power connection.

If there's demand, I can sketch out the mimic bus, as an idea.

 

[Ulsyus]

So I was thinking of the electrical system on a Beowulf, because I am weird like that, and a question occured to me.

What kind of electrical power does a ship's fusion plant produce?

Was there an in-game application to all this? Was it bought up by an engineer or such in your group, or did this just hit you out of the blue?

PS: The only engineer in our group is aeronautical, so this hasn't come up for me, just the occasional discussion about lifter bodies and hullframe stressors when they're scooping a gas giant so as to be able to refine fuel...

 

[Redcap]

Was there an in-game application to all this? Was it bought up by an engineer or such in your group, or did this just hit you out of the blue?

PS: The only engineer in our group is aeronautical, so this hasn't come up for me, just the occasional discussion about lifter bodies and hullframe stressors when they're scooping a gas giant so as to be able to refine fuel...

For me, a bit out of the blue, but in-game, I can see it useful in task failure situations :devil:

 

[Condottiere]

At the core of fusion science is plasma physics.

At extreme temperatures, electrons are separated from nuclei and a gas becomes a plasma—an ionized state of matter similar to a gas. Composed of charged particles (positive nuclei and negative electrons), plasmas are very tenuous environments, nearly one million times less dense than the air we breathe. Fusion plasmas provide the environment in which light elements can fuse and yield energy.

Three conditions must be fulfilled to achieve fusion in a laboratory: very high temperature (to provoke high-energy collisions); sufficient plasma particle density (to increase the likelihood that collisions do occur); and sufficient confinement time (to hold the plasma, which has a propensity to expand, within a defined volume).

In ITER, fusion will be achieved in a tokamak device that uses magnetic fields to contain and control the hot plasma. The plasma particles are heated—that is, sped up—by different types of auxiliary heating methods. The fusion between deuterium and tritium (DT) nuclei produces one helium nucleus, one neutron, and great amounts of energy.

CAPTURING THE ENERGY
More than 99% of the Universe exists as plasma, including interstellar matter, stars and the Sun. Examples of plasmas on Earth are: neon tubes, lightning, the northern lights (aurora borealis), and the glow of plasma televisions. (Click to view larger version...)

The helium nucleus carries an electric charge which will be subject to the magnetic fields of the tokamak and remain confined within the plasma, contributing to its continued heating. However, approximately 80 percent of the energy produced is carried away from the plasma by the neutron which has no electrical charge and is therefore unaffected by magnetic fields. The neutrons will be absorbed by the surrounding walls of the tokamak, where their kinetic energy will be transferred to the walls as heat.

In ITER, this heat will be captured by cooling water circulating in the vessel walls and eventually dispersed through cooling towers. In the type of fusion power plant envisaged for the second half of this century, the heat will be used to produce steam and—by way of turbines and alternators—electricity.

In terms of sheer scale, the energy potential of the fusion reaction is superior to all other energy sources that we know on Earth. Fusing atoms together in a controlled way releases nearly four million times more energy than a chemical reaction such as the burning of coal, oil or gas and four times more than nuclear fission.

https://www.iter.org/sci/MakingitWork

 

[Drakon]

Was there an in-game application to all this? Was it bought up by an engineer or such in your group, or did this just hit you out of the blue?

PS: The only engineer in our group is aeronautical, so this hasn't come up for me, just the occasional discussion about lifter bodies and hullframe stressors when they're scooping a gas giant so as to be able to refine fuel...

Where this is coming from: I play Traveller in Second Life, with some friends. I am in the process of building, in blender, a mesh version of the ship based on the deckplans and artwork in "Megatraveller Starship Operator's Manual" by Rob Coswell, et. al.

(We are playing a small planet, Fergus IV, during the year 1119. My character is a retired freetrader, hence the ship. At the moment, I have an unpainted "dummy" hull, and the captain's cabin, in world.)

This has been a slow process as I needed to learn how to operate blender prior to (and during) construction. Being able to utlize the class lessons on beds to work out the ship's furniture helped both endevours.

The eventual ship should allow one to live aboard, and hopefully fly, in game. I have the outer hull constructed, and the interior decking and bulkheads. The crew and passenger spaces are furnished. I have not started on the cockpit or the engine room, yet. What goes into a ship board engineroom depends on the type of equipment aboard. Whatever that equipment is, I need to build.

And well, to be honest, I am "that guy" the kind of guy who lays awake at night trying to answer such weird questions. It's a chronic condition that does not respond to treatment.

 

[Drakon]

At the core of fusion science is plasma physics.
...
CAPTURING THE ENERGY
...

In ITER, this heat will be captured by cooling water circulating in the vessel walls and eventually dispersed through cooling towers. In the type of fusion power plant envisaged for the second half of this century, the heat will be used to produce steam and—by way of turbines and alternators—electricity.

...

https://www.iter.org/sci/MakingitWork

Many many many years ago, I joined the naval nuclear power program because I figured that would as close to space travel as I could get in this lifetime. Never realized how close.

How tough would it be to build a steam plant that works in zero gravity?

 

[Grav_Moped]

Good enough for me; I can't explain it, either.

EOARN: Explain Only As Really Necessary. AKA Conservation of Handwavium.

There are at least two power systems: one for the "house" requirements (life support, electronics, and so on) and one for the "heavy" requirements (Drives, energy weapons, shields and so forth).

 

[flykiller]

in-game, I can see it useful in task failure situations

having some idea of where to start makes winging it easier.

A Beowulf is less than 50 meters long. Is it small enough to make the need for an AC set up superfluous?

yes.

How tough would it be to build a steam plant that works in zero gravity?

in zero grav a condenser won't work. but in traveller responsive internal gravitics are handwaved into existence, so there you go. but if your players ever ask what the heat sink is you'd better have an answer.