Maximum size of DPF device?

[Tulse]

I ran across this statement at the talk-polywell forums:

Remember, this work is really not in competition with Poly. There’s an upper limit to how large a FF reactor can be built and it’s a very low limit. We’re talking about 10 MW reactor IIRC. Would make a decent thruster if ganged together, but not gonna ever be worth ganging them for GW power. This is really intended for micro-distribution, so it’s not in competition with the Poly.

How correct is this? What is the most reasonable maximum power for a single DPF device? And how practical would it be to use DPF for main grid power? Would this involve a more distributed power approach, or could one create large generating stations with DPF?

[zapkitty]

Tulse wrote: I ran across this statement at the talk-polywell forums:

Remember, this work is really not in competition with Poly. There’s an upper limit to how large a FF reactor can be built and it’s a very low limit. We’re talking about 10 MW reactor IIRC. Would make a decent thruster if ganged together, but not gonna ever be worth ganging them for GW power. This is really intended for micro-distribution, so it’s not in competition with the Poly.

How correct is this? What is the most reasonable maximum power for a single DPF device? And how practical would it be to use DPF for main grid power? Would this involve a more distributed power approach, or could one create large generating stations with DPF?

From what I’ve read FF units were proposed in the 25 MWE range but the initial units have been scaled back to 5 MWe because of cooling concerns.

The FF core is small and if it’s generating 8 MWt then heat rejection is not so easy when you have to move a large amount of coolant through a small volume.

Though it’s true that 10 MWe units would be better and 25 MWe units better still….

If cooling is dealt with then at least the original 25 MWe FFs become feasible.

As for ganging mass quantities of FFs together for GWe power levels… at the currently proposed installation and overhead costs of FF units a gigawatt-class fossil fuel utility could replace all of its steam turbines with an equivalent wattage in 5 MWe FF boxes and still come out ahead… so that ‘s simply not an issue.

And 5 MWe designs can cut their teeth by providing peak power units on an as-needed basis so utilities won’t have to take an all-out plunge into fusion… they can test the waters first and make a profit in doing so.

[Tulse]

So is the scaling of individual units primarily limited by heat? I presume there must be some limits beyond that relating to the plasmoid formation and/or other basic aspects of DPF.

[Aeronaut]

Tulse wrote: So is the scaling of individual units primarily limited by heat? I presume there must be some limits beyond that relating to the plasmoid formation and/or other basic aspects of DPF.

First we need to remove excess heat. The higher the trigger pulse rate, the more electrical and thermal power generated. Next comes producing commercial amounts of electric energy. Beyond that come school/labs, theoreticians, and perhaps a somewhat larger version.

But in a multi-fusion world, FF will favor isolated and/ or stand-alone power plants which may or may not be grid-connected. Polywell favors centralized power generation, and boy are they going to have some cooling challenges! Anybody recall their target MWe and MWt figures?

[zapkitty]

Aeronaut wrote:

But in a multi-fusion world, FF will favor isolated and/ or stand-alone power plants which may or may not be grid-connected. Polywell favors centralized power generation, and boy are they going to have some cooling challenges! Anybody recall their target MWe and MWt figures?

Polywell initial target is 100 MWe at 80% efficiency, so that’s 120 MWt to deal with.

No mention of theoretical minimum or maximum MWe for Polywell that I can recall, with considerable speculation on 300+ GWe units etc…

[Aeronaut]

Thanx, Zap.Yep, plenty of speculation around that darkish project…

[Henning]

Polywell’s minimum power output is 100MWe. That’s because of its scaling law of size^5.

I’m not quite sure about FF’s limits itself, because DPFs scale linearly in respect to their size. So theoretically anything between beer-bottle-sized (for the whole device, but adding the cooling system) and big-factory-sized should be possible in maybe 30 years — if it’s possible at all.

[Henning]

That’s a range of maybe 1kW to 1GW. Yes, the engineering challenge is the heat transport, as mentioned earlier.

[Aeronaut]

As I understand it, powering a significantly larger DPF fusion reactor is going to take some serious power source engineering breakthroughs. Once the current generation goes into production we may be able to attract both the talent and other resources to tackle challenges like Cap 2.0, Switch 2.0, HV Buss 2.0, and so forth. The key thing here is that these are 2 entirely separate designs and technologies sharing the same theoretical underpinnings.

[zapkitty]

Smaller, as well… what would be the parameters and cost of a 25 kWe home unit?

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