Re: [FRIAM] new thermal tech

[Gary Schiltz]

Amusing indeed (the PV magazine article). The pump “reportedly
produces 3 kW to 4 kW of heat for every kilowatt of power it
consumes”. Say what?

On Fri, Jan 6, 2023 at 8:28 AM Roger Critchlow  wrote:
>
> I was amused to see an announcement of a thermoacoustic heat pump  the other 
> day:
>
>   
> https://www.pv-magazine.com/2023/01/02/residential-thermo-acoustic-heat-pump-produces-water-up-to-80-c/
>
> then an ionocaloric refrigerator announcement turns up this morning
>
>   https://newscenter.lbl.gov/2023/01/03/cool-new-method-of-refrigeration/
>
> It seems that you won't recognize your air conditioner in a few years.
>
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Re: [FRIAM] new thermal tech

[David Eric Smith]

I assume “delivers” would have been a better word choice than “produces”.  

After we create better schools to teach our kids government and citizenship, we 
should move on and teach them to understand thermodynamics.


> On Jan 6, 2023, at 12:27 PM, Gary Schiltz  wrote:
> 
> Amusing indeed (the PV magazine article). The pump “reportedly
> produces 3 kW to 4 kW of heat for every kilowatt of power it
> consumes”. Say what?
> 
> On Fri, Jan 6, 2023 at 8:28 AM Roger Critchlow  wrote:
>> 
>> I was amused to see an announcement of a thermoacoustic heat pump  the other 
>> day:
>> 
>>  
>> https://linkprotect.cudasvc.com/url?a=https%3a%2f%2fwww.pv-magazine.com%2f2023%2f01%2f02%2fresidential-thermo-acoustic-heat-pump-produces-water-up-to-80-c%2f&c=E,1,SIXaeD9pWPwQ9_a2yQcA2Mb6Oa19--caDioiCnI9tb9wHtj9F3T-fS0FbAdlNeoJjozEjvgRHvMxxDB874D65rIXmYYzllXMzQ-xbTUOen3OXZ0wb7n6ON_lX3U,&typo=1
>> 
>> then an ionocaloric refrigerator announcement turns up this morning
>> 
>>  
>> https://linkprotect.cudasvc.com/url?a=https%3a%2f%2fnewscenter.lbl.gov%2f2023%2f01%2f03%2fcool-new-method-of-refrigeration%2f&c=E,1,WtFGOsq-ZfdSeNDj-coqZXFEeJnYAea0pwlFL95XWPuzaTHMiuaDIsqM19iVS7Oaw1ElarAioZmixa4jBVRrZyrnp7sdhboRXZmwL4HYzjyNmyPqbA,,&typo=1
>> 
>> It seems that you won't recognize your air conditioner in a few years.
>> 
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Re: [FRIAM] new thermal tech

[Pieter Steenekamp]

I am somewhat puzzled by the discussion surrounding the efficiency of heat
pumps in relation to the laws of thermodynamics. If my understanding is
correct, the salient question being raised is whether it is possible for a
heat pump to transfer 3 to 4 kW of heat using only 1 kW of electricity,
which seems to contradict the laws of thermodynamics.

Allow me to clarify: a heat pump is not creating 3 to 4 kW of energy, but
rather transferring 3 to 4 kW of heat from a lower temperature to a higher
temperature using 1 kW of electrical energy. This is entirely within the
realm of thermodynamic principles, as I learned them in engineering school.
Heat pumps have been in use for some time, and it is not uncommon to find
off-the-shelf heat pumps capable of this task.

Pieter

On Fri, 6 Jan 2023 at 19:34, David Eric Smith  wrote:

> I assume “delivers” would have been a better word choice than “produces”.
>
> After we create better schools to teach our kids government and
> citizenship, we should move on and teach them to understand thermodynamics.
>
>
> > On Jan 6, 2023, at 12:27 PM, Gary Schiltz 
> wrote:
> >
> > Amusing indeed (the PV magazine article). The pump “reportedly
> > produces 3 kW to 4 kW of heat for every kilowatt of power it
> > consumes”. Say what?
> >
> > On Fri, Jan 6, 2023 at 8:28 AM Roger Critchlow  wrote:
> >>
> >> I was amused to see an announcement of a thermoacoustic heat pump  the
> other day:
> >>
> >>
> https://linkprotect.cudasvc.com/url?a=https%3a%2f%2fwww.pv-magazine.com%2f2023%2f01%2f02%2fresidential-thermo-acoustic-heat-pump-produces-water-up-to-80-c%2f&c=E,1,SIXaeD9pWPwQ9_a2yQcA2Mb6Oa19--caDioiCnI9tb9wHtj9F3T-fS0FbAdlNeoJjozEjvgRHvMxxDB874D65rIXmYYzllXMzQ-xbTUOen3OXZ0wb7n6ON_lX3U,&typo=1
> >>
> >> then an ionocaloric refrigerator announcement turns up this morning
> >>
> >>
> https://linkprotect.cudasvc.com/url?a=https%3a%2f%2fnewscenter.lbl.gov%2f2023%2f01%2f03%2fcool-new-method-of-refrigeration%2f&c=E,1,WtFGOsq-ZfdSeNDj-coqZXFEeJnYAea0pwlFL95XWPuzaTHMiuaDIsqM19iVS7Oaw1ElarAioZmixa4jBVRrZyrnp7sdhboRXZmwL4HYzjyNmyPqbA,,&typo=1
> >>
> >> It seems that you won't recognize your air conditioner in a few years.
> >>
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Re: [FRIAM] new thermal tech

[Steve Smith]

Gary Schiltz wrote:

Amusing indeed (the PV magazine article). The pump “reportedly
produces 3 kW to 4 kW of heat for every kilowatt of power it
consumes”. Say what?


this is just the typical way that a "heat pump" works, not by creating 
the energy in the power, just by concentrating it... ejecting 
warmer/cooler air/water on the opposite side of the system...


The wider range of air-source functioning: -15 to 50C  and being 
hydromechanically suitable for liquid-sourcing (e.g. run water through a 
pipe buried in the ground, or ground-water being pumped for irrigation) 
makes it yet more suitable.


First glance on the article suggests a better duty cycle with(out) the 
kinds of moving/friction parts compressors come with (conventional 
heat-pump)...


I don't know much about the environmental or practical implications of 
using Helium as a working fluid...  huge molecular size compared to H, 
but a fraction of most other working gasses?


The 3-4/1 coefficient of performance implied by the article numbers is 
roughly 10-14EER  or 12-17SEER  to compare with commercial 
HVAC/Mini-Split numbers...   so in the same general range?


I've never looked hard, but have been curious about an 
ammonia-working-fluid heat-source refrigeration system (usually used as 
an off-grid/RV Propane fridge).  Seems like concentrated solar-thermal 
driving refrigeration (or heat pumping in reverse?) would be pretty 
elegant?   Ammonia as a working fluid also seems lower-industrial and 
presumably more environmental than it's more industrial cousins?  I knew 
people growing up who lived without electric service who had these funny 
looking refrigerators which had a pilot-light-sized flame in the back 
that "made them cool"... from a propane tank... crazy talk I thought  then!




On Fri, Jan 6, 2023 at 8:28 AM Roger Critchlow  wrote:

I was amused to see an announcement of a thermoacoustic heat pump  the other 
day:

   
https://www.pv-magazine.com/2023/01/02/residential-thermo-acoustic-heat-pump-produces-water-up-to-80-c/

then an ionocaloric refrigerator announcement turns up this morning

   https://newscenter.lbl.gov/2023/01/03/cool-new-method-of-refrigeration/

It seems that you won't recognize your air conditioner in a few years.

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Re: [FRIAM] new thermal tech

[David Eric Smith]

The thermoacousktic one is interesting, and surprises me a bit.

I worked on these systems a bit in the mid-1990s, when in a kind of purgatory 
in a navy research lab that mostly did acoustics.

Broadly, there are two limiting cases for a thermoacoutic engine.  One uses a 
standing wave and is simple and robust to design and run.  The other uses a 
traveling wave and is much harder to tune and keep tuned.

A difference is that the SW version, which we might say runs on a 
“thermoacousktic cycle”, makes intrinsic use of the phase lag for diffusion of 
heat through a boundary layer.  As such, it has no nontrivial reversible limit, 
and has severe limits on the efficiency (or coefficient of performance, if you 
are running it as a refrigerator).  So hearing that they get COPs comparable to 
existing mechanical systems would make me suspicious of they were using SW.

The TW version runs on, effectively, the Stirling cycle, and in principle it 
does have a reversible, Carnot-efficient limit.  However, it has parasitic 
losses from viscous boundary layers.  The engineering limit you need to 
approach ideal thermal transfer efficiency is one that chokes off the flow of 
the working fluid, and makes the viscous drag explode.  Using an ideal gas like 
He reduces the viscosity, though also the heat capacity and diffusion rate 
through the fluid.

On their website, they have a little advertising graphic of a sound wave, which 
shows a traveling wave (or a mixed wave with large TW component).  It would be 
reasonable, if they are scientists or engineers, for them to make their public 
graphics true representations of at least qualitatively what their system does. 
 

In view of the fact that there is very little conceptual to do with a 
thermoacousktic engine, and it is all materials science and tweaking 
engineering details, I really wonder what would have taken 27 years to figure 
out, or to get around to doing.


For geeks who like this stuff, there is a fun continuum:

1. When I was a little kid, I got an ultra-simple Stirling engine from a mail 
advertisement (back when those weren’t all scams), and was delighted by it.

2. In reading more about Stirling cycles etc., I learned about “free-piston” 
Stirling engines, which have the same compartments and barriers, but use the 
compression-bounce of the gas to move the displacer piston rather than a 
mechanical linkage.

3. The TW thermoacousktic engine is just a free-piston Stirling without the 
piston: the shuttle of gas becomes the displacer.

4. Some years later, having been thrown out of String Theory for being too 
stupid to understand it, I was interested in the way adiabatic transformations 
look like mere coordinate deformations in state spaces, which means that one 
should be able to make Carnot-efficient reversible movement identical to 
equilibrium by use of a conformal field (the String Theorist’s universal 
symmetry transformation, back in those days).  So we can do thermoacousktic 
engines using String Theory (Horray!):
https://journals.aps.org/pre/abstract/10.1103/PhysRevE.58.2818 

http://www.santafe.edu/~desmith/PDF_pubs/Carnot_1.pdf 

and then 
https://journals.aps.org/pre/abstract/10.1103/PhysRevE.60.3633 

http://www.santafe.edu/~desmith/PDF_pubs/Carnot_2.pdf 

Papers I know no-one has ever had any interest in, and very possibly no-one has 
ever read.

I thought it was very fun to be able to derive Carnot’s theorem directly from a 
symmetry transformation, so entropy flux behaves like any other conserved 
quantity, rather than having to make arguments about limits to thermodynamic 
efficiency by daisy-chain proofs-by-contradiction (If you could do 
such-and-such, then by running an exemplar Carnot engine in reverse, you could 
make a perpetual-motion machine of type-XYZ).  But I never did anything with it 
that yielded a new calculation, as opposed to just a restatement of common 
knowledge.

Anyway…

Eric





> On Jan 6, 2023, at 8:27 AM, Roger Critchlow  wrote:
> 
> I was amused to see an announcement of a thermoacoustic heat pump  the other 
> day:
> 
>   
> https://www.pv-magazine.com/2023/01/02/residential-thermo-acoustic-heat-pump-produces-water-up-to-80-c/
>  
> 
> 
> then an ionocaloric refrigerator announcement turns up this morning
> 
>   https://newscenter.lbl.gov/2023/01/03/cool-new-method-of-refrigeration/ 
> 

Re: [FRIAM] new thermal tech

[Roger Critchlow]

I learned most everything I know about thermoacoustic heat engines while
trying to read those papers, then I went back to the day job hacking code.

-- rec --


On Sun, Jan 8, 2023 at 6:34 AM David Eric Smith  wrote:

> The thermoacousktic one is interesting, and surprises me a bit.
>
> I worked on these systems a bit in the mid-1990s, when in a kind of
> purgatory in a navy research lab that mostly did acoustics.
>
> Broadly, there are two limiting cases for a thermoacoutic engine.  One
> uses a standing wave and is simple and robust to design and run.  The other
> uses a traveling wave and is much harder to tune and keep tuned.
>
> A difference is that the SW version, which we might say runs on a
> “thermoacousktic cycle”, makes intrinsic use of the phase lag for diffusion
> of heat through a boundary layer.  As such, it has no nontrivial reversible
> limit, and has severe limits on the efficiency (or coefficient of
> performance, if you are running it as a refrigerator).  So hearing that
> they get COPs comparable to existing mechanical systems would make me
> suspicious of they were using SW.
>
> The TW version runs on, effectively, the Stirling cycle, and in principle
> it does have a reversible, Carnot-efficient limit.  However, it has
> parasitic losses from viscous boundary layers.  The engineering limit you
> need to approach ideal thermal transfer efficiency is one that chokes off
> the flow of the working fluid, and makes the viscous drag explode.  Using
> an ideal gas like He reduces the viscosity, though also the heat capacity
> and diffusion rate through the fluid.
>
> On their website, they have a little advertising graphic of a sound wave,
> which shows a traveling wave (or a mixed wave with large TW component).  It
> would be reasonable, if they are scientists or engineers, for them to make
> their public graphics true representations of at least qualitatively what
> their system does.
>
> In view of the fact that there is very little conceptual to do with a
> thermoacousktic engine, and it is all materials science and tweaking
> engineering details, I really wonder what would have taken 27 years to
> figure out, or to get around to doing.
>
>
> For geeks who like this stuff, there is a fun continuum:
>
> 1. When I was a little kid, I got an ultra-simple Stirling engine from a
> mail advertisement (back when those weren’t all scams), and was delighted
> by it.
>
> 2. In reading more about Stirling cycles etc., I learned about
> “free-piston” Stirling engines, which have the same compartments and
> barriers, but use the compression-bounce of the gas to move the displacer
> piston rather than a mechanical linkage.
>
> 3. The TW thermoacousktic engine is just a free-piston Stirling without
> the piston: the shuttle of gas becomes the displacer.
>
> 4. Some years later, having been thrown out of String Theory for being too
> stupid to understand it, I was interested in the way adiabatic
> transformations look like mere coordinate deformations in state spaces,
> which means that one should be able to make Carnot-efficient reversible
> movement identical to equilibrium by use of a conformal field (the String
> Theorist’s universal symmetry transformation, back in those days).  So we
> can do thermoacousktic engines using String Theory (Horray!):
> https://journals.aps.org/pre/abstract/10.1103/PhysRevE.58.2818
> http://www.santafe.edu/~desmith/PDF_pubs/Carnot_1.pdf
> and then
> https://journals.aps.org/pre/abstract/10.1103/PhysRevE.60.3633
> http://www.santafe.edu/~desmith/PDF_pubs/Carnot_2.pdf
> Papers I know no-one has ever had any interest in, and very possibly
> no-one has ever read.
>
> I thought it was very fun to be able to derive Carnot’s theorem directly
> from a symmetry transformation, so entropy flux behaves like any other
> conserved quantity, rather than having to make arguments about limits to
> thermodynamic efficiency by daisy-chain proofs-by-contradiction (If you
> could do such-and-such, then by running an exemplar Carnot engine in
> reverse, you could make a perpetual-motion machine of type-XYZ).  But I
> never did anything with it that yielded a new calculation, as opposed to
> just a restatement of common knowledge.
>
> Anyway…
>
> Eric
>
>
>
>
>
> On Jan 6, 2023, at 8:27 AM, Roger Critchlow  wrote:
>
> I was amused to see an announcement of a thermoacoustic heat pump  the
> other day:
>
>
> https://www.pv-magazine.com/2023/01/02/residential-thermo-acoustic-heat-pump-produces-water-up-to-80-c/
> 
>
> then an ionocaloric refrigerator announcement turns up this morning
>
>   https://newscenter.lbl.gov/2023/01/03/cool-new-method-of-refrigeration/
>