Looking for small refrigeration technology

[okweplay]

I am looking for any type of refrigeration that might be used to
keep half of a little lunch box cool. Something that would be able to work off batteries. I don't know if this exists but it seemed that this would be the right place to find out.
I am not looking for refrigeration for 12 volt use in a car a I am trying to see if there is any technology for small type portable that can convet a regular size portable lunch box and refrigerate like half of it.

Thanking You In Advance For Your Help

Jerry
okweplay@aol.com
954-394-6309

[botrous]

okweplay , there is refrigerators that works with car battery , here it costs about 30 USD , just check for that at a car accesory shop and i'm sure you'll find what you are looking for

[wesmax]

okweplay , there is refrigerators that works with car battery , here it costs about 30 USD , just check for that at a car accesory shop and i'm sure you'll find what you are looking for

these are thermo electric friges

[Deejey]

Do I understand that you want to convert your lunch box into a fridge that runs on 12 volts?

[okweplay]

Not 12 Volt but more portable that can be carried to the job or beach that runs on regular batteries or some kind of rechargable
battery
Thank You
Jerry

[frank]

have a look here. this explains what you are after http://home.howstuffworks.com/refrigerator6.htm

[eggs]

I have the answer !
It's not 12v, so is very, very cheap to run
It is VERY portable.
A few of the lads, carry them to work everyday.
I always carry one to the beach.
It is fully rechargable, without capacity loss or false memory problems.

You can get them free at Shell petrol stations when you fill your van up.

Cue drum roll........................ ........................... ..................... ....................... ............................


Da Dahhhhhh

A cooler bag.

Cheers

Eggs

[Peter_1]

Not 12 Volt but more portable that can be carried to the job or beach that runs on regular batteries or some kind of rechargable
battery
Thank You
Jerry

With an eutectical plate in it.

[bersaga]

Thermoelectrics are the solution for you - there many module sizes available complete with fans. But they are very expensive. I worked on a project where we planned to use this on telecom mini cabinets i.e. get power from the sun to keep the cabinet cool inside ( opposite of what you're planning to do ) - but it was to damn expensive!

[Abe]

Eggs found your solution.................Cooler Bag
BP do a good deal

[botrous]

Nice idea , petrol stations are doing the job

[smileypete]

Hi,

Freeze a can of beer and put it with your lunch, at least you can then drink it and save the effort of lugging it home!

Might be best to put the can in a bag when freezing in case it splits, but I've never had that problem.

Or freeze a 500ml plastic bottle of water but leave 1/11th for expansion of the ice.

I've also found that a fleece and a layer of mylar (aluminised plastic) wrapped around and around foodstuffs will keep some meat frozen solid for a couple of hours.

(coolie bags... sheesh! )

cheers,
Pete.

[botrous]

smileypete , you posted the same article twice , try to erase one . . . . . . .

[ksvinod]

oh dear, i think you may go for thermoelectric refrigeration system??///////

that will help U

regards

vinod

[neil sailes]

I found a good link for a company in China that even cater for a cup size cooler. http://www.jingeao.com/products.php?p=4

Neil

[bersaga]

Anyone looking to purchase Chinese A/C Split Units ( 1- 5 hp - Heating/Cooling ) ? I have a supplier coming to see me in Kuala Lumpur this Thursday- direct from the Plant. And I will also be visiting the Plant early October. Perhaps, if the collective order is huge and then I can get in a couple of containers worth of shipment and get a better price. Also may be able to get a better price if I say that the consignment is for SEA rather than for US/Europe.

[frank]

Anyone looking to purchase Chinese A/C Split Units ( 1- 5 hp - Heating/Cooling ) ? I have a supplier coming to see me in Kuala Lumpur this Thursday- direct from the Plant. And I will also be visiting the Plant early October. Perhaps, if the collective order is huge and then I can get in a couple of containers worth of shipment and get a better price. Also may be able to get a better price if I say that the consignment is for SEA rather than for US/Europe.

Can you also get spares and backup in the containers?

[US Iceman]

Here is something that may be of interest to you.

Sterling Cycles for Refrigeration Purposes

http://www.sesusa.org/

This seems to be getting more mainstream and commercially viable.

Regards,
US Iceman

[neil sailes]

Hi Iceman.

On the Sterling Engine design does this mean you need a big 'engine' to produce a low level of cooling ?

Neil

[US Iceman]

Hi Neil,

That's a very good question.

I have only looked at this technology briefly. More out of curiosity, than for any serious venture.

I remember there were several manufacturers that made small systems. I think some were for small marine applications (pleasure boats, etc.).

I'll try to do some more research and report back any findings.

Since these are heat driven machines there should be some viable commercial application... if the system does not cost too much.

Regards,
US Iceman

[US Iceman]

Here is a quick list of references found:

http://www.sunpower.com/

http://www.stirlingengine.com/

http://www.infiniacorp.com/main.htm

Here is a link that has a decent explanation:

http://www.stirlingenergy.com/whatisastirlingengine.htm

Does anyone on this forum have experience with this?

US Iceman

[neil sailes]

Iceman.

Reading up on what you posted, I am starting to get an idea of how it works, it still works on the Carnot cycle using expansion and compression. But it does it silently and effieciently, plus it has no ODP potential. If you can get this working on a large scale, you will have to let me know how it goes.

Neil

[US Iceman]

Hi Neil,

One of the links posted was for power generation using solar energy. They had systems up to 1 Megawatt I think.

In any regard, this is very interesting and I would like to see how this could be used for large scale refrigeration systems.

US Iceman

[frank]

I am starting to get an idea of how it works, it still works on the Carnot cycle using expansion and compression.

Hi Neil

The Carnot Heat Engine is a theoretical cycle that has the ultimate efficiencies that all other cycles strive to achieve. The closer you can get your "real" cycle to emulate the Carnot Cycle the more efficient the system will be. The Carnot Cycle does not exist in real life.

All irreversible (actual) heat engines operating between two temperature limits will have lower efficiencies.
Have a look here http://hyperphysics.phy-astr.gsu.edu...mo/carnot.html

The Carnot Cycle has a zero % loss or change of entropy (non useful energy) and all real life engine cycles have at least some entropy. Look at all the links in the web site - very useful.

[neil sailes]

Thanks Frank.
So the carnot cycle is just an ideal model of true effeciency. What I should of put in is reverse-Carnot cycle.

Neil

[neil sailes]

Hi Iceman.
I was looking up more information on the Sterling engine and found a company that makes 55kw generators that will run of any flammable gas (methane,propane etc) the site I was looking at was http://www.stmpower.com/Technology/B...HighEfficiency

Neil

[slingblade]

LOL there is no such thing as a battery powered lunch box cooler, why dont you try ebay.

[wesmax]

Yes their is a lunch box cooler it is thermoelectric and available here in canada

wesmax

[JimmyMurphy]

Thermo electric refrigeration is way too expensive and way too inefficient for any "lunchbox" use that you would want to tryout. Id reccomend buying dry ice and puting a little bit in your lunchbox, but be careful not to put it directly in contact with foods such as fruits as they may get freezer burn. ORRRR put some water with lots of salt in it and fill with ice.. this will give you water 2-3 degrees colder then freezing.