Mains power voltage drop to reduce usage?

Oh dear.

I think John is mentally ill.

Not exactly true...depending on what you mean by 'current'

Not many coal are much different from nukes - all about 37% at full load

With nukes you can of course do better - gas or sodium cooled can go way hotter, but why bother? advanced tech is expensive, uranium is dirt cheap.

Look at 'Natrium' where the reactor is to be cooled by molten salt, which is stored in a heatbank to help the reactor respond to peak demands. Add more water, instant increase in steam

I think you are an amateur flamer who doesn't want to, probably can't, intelligently discuss electronics or thermals. Your prime motivation is to be nasty.

Imagine a boost converter.

Imagine a water heater that has exhaust flue gas temp of 100c and heats water to 200c. Try.

Actually, it doesn't even need a heat pump.

I'd need a charger for them*. And I only use them in low consumption devices like clocks. I've got rechargeable AAs and AAAs and a charger for them, but I don't use them in things like remote controls as the batteries last a year or more.

• I used to have a charger that charged a single NiCad button cell. It consisted of a resistor and a diode.

The cell fitted a Russian MW/LW personal radio that was 1"x3/4"x1/4"**. It used a thin-film integrated circuit with discreet transistors &c.

With a counter-flow heat exchanger, flue gasses could easily be colder than the hot water output.

Jeroen Belleman

Yes, that's one obvious way.

So obvious that in 200 years of steam engines no one has thought of it Wow! F****ng Genius!

I used to design control systems for steamships. Water temp was maybe

So I'm not mentally ill after all. What a relief.

There are lots of other examples of water hotter than flue gas. Your turn.

What are you dribbling on about?

Seeing if you can think. Seems not.

Bye.

This is obvious:

Start status:

Hot gasses flow: 200°C -->-->-->-->-->-->-->-->

Stable status:

Hot gasses: 200°C -->-->-->-->-->-->-->--> cold gases at almost 15°C Hot water at <--<--<--<--<--<--<--<-- cold water 15°C nearly 200°C

But the output gases can not get colder than 15°C in that example, without a heat pump.

And curiously, if you put in a heat pump, the heat pump will use more energy than the extra energy you will get out of your steam engine.

Which is why not one persons in over 200 years of steam engine design, has ever bothered to do it.

You can get much better from a cooling tower where the latent heat of evaporation pulls a few more degrees out of the typically 45 degree turbine exhaust temperature.

They didn't need a heat pump, as the superheaters (driven by flue gasses) were sufficient for their purposes.

The steam turbines on big ships had superheaters, preheaters, economizers, geared HP and LP turbines, steam powered electric generators, steam powered feedwater pumps, distillers, and domestic water heaters. And enormous sea-water condensers. They didn't waste any heat.

But the plants were so complex that owners couldn't find the crews to keep them running. They had a chemical lab for the feedwater.

Direct-drive reversing diesels are so much simpler.

Notice that the superheater is counter-current, so the flue gas will be closer to the temperature of the condensate that the combustion gasses from the flame.

Joe Gwinn

onsdag den 16. november 2022 kl. 01.16.01 UTC+1 skrev John Larkin:

and probably more efficient but requiring a bit more maintance