Nitrogen as an Energy Store …

[duncan webster 1Participant @duncanwebster1]

Posted by Vic on 12/01/2021 11:35:37:

Gravity storage.

**LINK**

so we've got 35 te of concrete being lifted through 33 stories, say 100m. That's a potential energy of 35*9.81*100 = 34.335MJ. Sounds a lot, but allowing 300 cc of water per brew, heated through 90C with a specific heat of 4.19 KJ/Kg.K it takes 113 KJ to heat the water to make a cup of tea, so the energy stored is enough for 304 cups of tea. Not near enough for one cup per resident of a 33 storey block. For reference Dinorwig has a storage capacity of 33 terraJoules, that's near enough 1 million of these crane affairs

It would make a lot more sense to me to have a big tank of water on the roof and use Magic Mountain technology. Or even a big tank of water in the basement, use it for space heating the flats, heat it up when excess power available. Even better use wax, which has a phase change so can absorb/give out a lot of heat without changing temperature

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Andy Stopford on 12/01/2021 11:50:25:

There was a more expansive discussion on this on Radio 4 yesterday:

https://www.bbc.co.uk/programmes/m000r368

[…]

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Perhaps unsurprising, as the originally linked page was effectively an advert for that programme

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JA on 12/01/2021 11:42:31:

[…]

I think the idea that started this thread (and the similar one a few months ago) considered Nitrogen as a compressed gas, not a liquid.

JA

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Sorry, JA … as the originator of this thread, I must dispute that. ^^^

MichaelG..

[JAParticipant @ja]

MichaelG

Apologies.

JA

[Michael GilliganParticipant @michaelgilligan61133]

Thanks, JA … no offence taken, I just wanted to set the record straight.

MichaelG.

[Andy StopfordParticipant @andystopford50521]

It would seem that Sainsbury's trialled it in 2016:

https://www.coolingpost.com/uk-news/sainburys-to-trial-dearman-engine/

No details as to how the trial went, unfortunately.

Most of the descriptions of how it works are mangled by journalistic Chinese whispers; it appears to be a piston engine which uses a warm water/glycol mixture to flash liquid nitrogen to gas, i.e. the water/glycol provides the 'hot' part of the thermodynamic cycle and I'm guessing that it's in the form of steam, since there are mentions of it being compressed prior to N2 injection, and that's suggested by this diagram;

https://revolution-green.com/piston-engine-driven-expansion-liquid-nitrogen-liquid-air/

[Michael GilliganParticipant @michaelgilligan61133]

More about the engine, here: **LINK**

https://www.apcuk.co.uk/news/cool-clean-seen-dearman-engine/

MichaelG.

[pgk pgkParticipant @pgkpgk17461]

This Link

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjtyeiZ2ZbuAhUX3IUKHVMiCNgQFjADegQIBRAC&url=https%3A%2F%2Ffuturepowertrains.co.uk%2F2015%2Fassets%2Fdownloads%2Fpresentations%2Fnick-owen.pdf&usg=AOvVaw0er1ilgXRsi-TPtDWd99c9

Gives detais on how it works and this statement:
Predicted performance (2ndgeneration)>140Wh chilling per kg LiNin a frozen TRU application –payback vs competition, zero emissions

pgk

[Michael GilliganParticipant @michaelgilligan61133]

Clean Cool Energy

https://youtu.be/BnvZuOK1McU

**LINK**

MichaelG.

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… Sorry, can’t work out how to do the embedding thing on the iPad

… I have no menu for selecting frame width

[Peter SansomParticipant @petersansom44767]

In the late 70's early 80's I worked on a on an Oxygen plant, Air Separation Unit on a steel works. The steel making process use 750t of gaseous oxygen per day and about 300t of gaseous nitrogen. Yes some liquid Oxygen and Nitrogen was produced, stored for when demand could not be met by gas production, or sold to Linde Gas.

Liquid Nitrogen is not free, there is a cost. The bulk of the liquid Oxygen and Nitrogen after being separated products is returned to gas and in this part of the process is used to cool the incoming air. Storing higher levels of liquid causes increased liquification costs.

These plants are installed in which there is a high demand for the gaseous product, Steel works, petrochemical plants etc. Liquid is not the primary product, it is the method of separating the products. Liquid is used for long term storage and for easy transport unless you are in the rocket business.

[Author]

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