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Steam Networks

worksinprogress.co

141–150 of 161 posts

Re: Steam Networks

#141

Earlier quoted context omitted.

A LOT of universities have a central heat plant that pumps hot water to all the other buildings. I think steam has been phases out because it is so much more dangerous and electric pumps make it unnecessary.

Yeah, a lot of institutions are removing steam for heating and replacing it with glycol loops.

Must be a lot lower maintenance.

Re: Steam Networks

#142

> The last total system failure was in 2007, when an 82-year-old pipe at 41st and Lexington exploded, showering Midtown in debris. Heavy rainfall had cooled the pipes, producing large amounts of condensate quickly, and a clogged steam trap meant that the system was unable to expel the water. When this build-up hit a critical level, the internal pressure shot up, causing the explosion. Almost fifty people were injured…

I happened to be walking a few blocks north and one east of this when it happened. I saw dozens of people running up the street in a panic. Office ladies running barefoot with their heels in hand. I asked what had happened and they said there was a giant explosion that could only have been terrorism.

The wikipedia article has a few more photos: https://en.wikipedia.org/wiki/2007_New_York_City_steam_explo...

The aftermath photo gives you a good sense of it: https://www.nbcnews.com/id/wbna20184563

Re: Steam Networks

#143
post #90

Earlier quoted context omitted.

Those electrical systems are about 85% efficient once the chemical energy in the coal has been converted to kinetic energy in the turbine. Losses in the generators themselves and in voltage loss through transformers and wires add up to about 15%. But they're only about 33% (old tech) to 45% (best-case new tech) efficient when it comes to thermal potential. Burning coal or natural gas produces lots of heat, and while…

Random thought: could you insulate high voltage wires in pipes and blow cold air through those? Any loss would become “free” heating for homes nearby.

I suppose, but (off the top of my head):

- insulating high voltage lines isn't trivial

- the conductor will be hot inside the insulation...

- service cost of either system will be increased (by rather a lot, I'd guess)

Re: Steam Networks

#144
post #136
post #101

Earlier quoted context omitted.

I feel like this could be a nice high school physics test question. Realistically, I don't think HV lines have much energy loss, owing to the use of high voltage in the first place as a means of minimizing loss. Then there are considerations for air resistance in the tubes, an almost 100% effective insulator, and all those real world issues of gnarly general maintenance. Almost all electricity run through computers a…

Could not find the answer, kept getting general pages about how much current a wire can pass (without the result even containing the keyword I looked for, like temperature or heat or warm). To still have some indication of whether this is an interesting thing to keep looking into, ChatGPT says: > Typically, high-voltage transmission lines are designed to operate at temperatures of around 75 to 100°C (167 to 212°F). H…

It's entirely possible the wires would get hot enough to get useful heat, but I think the much more practical challenge is moving the air and insulating it from the outside.

Beyond that, you're likely also decreasing the maximal electrical current the wires can carry, as they won't be able to dissipate the heat as effectively with the additionally insulation.

Re: Steam Networks

#145
post #95

Earlier quoted context omitted.

You have to go quite far north for -20F to become frequent.

If it EVER gets to -20 that is what matters. You need to prepare for the worst case weather, not the common ones.

Fortunately resistive heating is just about the cheapest possible heating in capital costs and trivial to retrofit as a backup.

Re: Steam Networks

#146
post #95

Earlier quoted context omitted.

You have to go quite far north for -20F to become frequent.

If it EVER gets to -20 that is what matters. You need to prepare for the worst case weather, not the common ones.

It will still work, just not as efficently as in normal temperatures. So you're using 50kWh for the 3 days a year it's that cold and 10kWh for the other 362 - better than using 20kW every day.

Re: Steam Networks

#147
post #146
post #95

Earlier quoted context omitted.

If it EVER gets to -20 that is what matters. You need to prepare for the worst case weather, not the common ones.

It will still work, just not as efficently as in normal temperatures. So you're using 50kWh for the 3 days a year it's that cold and 10kWh for the other 362 - better than using 20kW every day.

Only if there is enough power generation

Re: Steam Networks

#148
An incredibly interesting piece. I live in NY, but didn't know the history.

This did make me chuckle

> reduces your lifespan by about 18 minutes

As George Carlin said, "yeah, but it's the last 18 minutes".

Re: Steam Networks

#149
> Traditional fireplaces are immensely inefficient, drawing in 300 cubic feet of air per minute for combustion and expelling up to 85 percent – along with the heat – up the chimney.

So the other 45 cubic feet exhaust per minute go where? Into the rooms to suffocate the people there?

Re: Steam Networks

#150

> Traditional fireplaces are immensely inefficient, drawing in 300 cubic feet of air per minute for combustion and expelling up to 85 percent – along with the heat – up the chimney. So the other 45 cubic feet exhaust per minute go where? Into the rooms to suffocate the people there?

Also, isn't that heat only convection? This doesn't seem to take into account the fact that brick or stone fireplaces absorb heat and then radiate it back into the room. It's not all about moving hot air. The fireplace itself gets hot and that feeds back into the room through radiative heat.
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