advanced refrigeration technology

Search google for "advanced refrigeration technology" and find an article ,copy it below for there “thermo-acoustic" and "magnetic refrigerator " interest me much. Who're familiar with this topic may teach me more:):confused:

Some cool ideas
From The Economist print edition

Traditional refrigeration may be eased out by new technologies

THE basic technology of refrigeration has not changed much since the 19th century. Refrigerators (and their cousins, air conditioners) work by compressing a fluid and then allowing it to expand. Compression heats the fluid up, thus heating its surroundings. Expanding it cools it down, thus cooling its surroundings. Arrange for the compression to happen in one place and the expansion in another, and heat will be pumped from the latter to the former. Pick the right fluid and you can move a lot of heat.

Early refrigerators used ammonia, which is poisonous. Then chlorofluorocarbons (CFCs) were discovered. They are not poisonous, and quickly displaced ammonia. But CFCs were implicated in the destruction of the ozone layer that protects the Earth from ultraviolet light, and were banned. So ammonia came back into fashion. Now, technologists are working on several completely different ways of cooling things.

Pumped up
The least different way is called closed-cycle air refrigeration. Instead of employing special fluids such as CFCs or ammonia, it uses air itself as the working fluid.

Open-cycle air refrigeration, in which air is compressed, allowed to shed the heat this generates, and then blown into the space to be cooled, is already used in some sorts of air conditioning—for example, on aircraft. It is safe, since the pressures involved are low, but it is inefficient, because the cooled air is lost to the system.

A closed cycle (ie, a sealed system similar to a traditional refrigerator) can be more efficient than an open one, but that efficiency requires the air to be pressurised to a much higher level. Indeed, the reason why CFCs and ammonia were used in the first place is that they are more compressible than air, and thus deliver more refrigeration for a given pressure. The trick, therefore, is to generate and contain the extra pressure safely.

A collaboration between America's National Institute of Standards (NIST) and several American refrigeration companies has overcome these problems. To generate the 82 atmospheres of pressure needed requires a pump shaft that can rotate 30,000 times a minute, and can do so at temperatures between -50°C and -100°C. That, in turn, required the development of new seals between the shaft and its housing. These have specially designed spiral grooves that eliminate the need for lubricants, since those can fail at such high pressures and low temperatures.

Besides getting rid of expensive and potentially dangerous coolants, closed-cycle refrigeration chills things faster than conventional refrigeration. That should improve food safety, as packaged frozen foods will spend less time in the temperature range conducive to bacterial growth. Foods frozen using this technique should taste better, too, as faster cooling means less dehydration. All told, NIST says, these benefits should be worth hundreds of millions of dollars a year, even if only a handful of large industrial refrigeration plants switch over.

Sounds good
Closed-cycle air refrigeration still uses the compression and decompression of a circulating fluid. Another new technique abandons even that. Sound is normally thought of as a pressure wave. But, like any other pressure change, it also brings a change in temperature. In an ordinary conversation, that temperature change is a mere ten-thousandth of a degree. But a loud sound in a pressurised gas can cause significant temperature changes. Such sounds can be made without any moving parts by the use of a resonating cavity. The lack of moving parts means that devices depending on “thermo-acoustic” effects can be made to be much more efficient than conventional refrigerators.

A collaboration between America's Los Alamos National Laboratory and Praxair, an industrial-gas company based in Connecticut, is in the process of commercialising this idea. Praxair is interested in using it to liquefy natural gas.

The trick in building thermo-acoustic refrigerators lies in synchronising the pulses of sound in such a way that little packets of cold fluid are pushed one way, while little packets of heated fluid move in the opposite direction. In this case, pressurised helium is used to conduct heat away from the natural gas. The helium is pushed through a thin mesh of steel wires to break it up into packets. By adjusting the size of the resonating cavity, and of the mesh, the sound waves can be made to cool the helium, which in turn cools the natural gas.

An attractive alternative
A third new refrigeration technology may see use not just in industrial plants, but also in the air-conditioning systems of cars, and perhaps even in household refrigerators. It has been known for a long time that certain substances heat up when placed in a magnetic field, and cool down when the field is removed. Unfortunately, this effect is large enough to be useful only in a handful of rather exotic materials, most notably alloys of gadolinium. And the magnetic fields involved need to be very powerful.

Until 2001, superconducting magnets had to be used to produce strong enough magnetic fields. However, in that year Karl Gschneidner, a researcher at Ames, a Department of Energy research lab in Iowa, succeeded in making a magnetic refrigerator using strong permanent magnets. This magnetic refrigerator work by using a rotating wheel containing gadolinium alloy. The rotation takes the alloy in and out of the magnetic field, alternately heating and cooling it. Water cooled by the cold alloy is then circulated through coils like those found in a regular refrigerator. A cool idea indeed.

this i think is trane's new approach to high efficiency systems and technology development too, it is indeed a fascinating realm of science.

thanks for the info!

Hi Lc shi
Thank you for this interesting post - of which I've been awaiting. So just to get you a little more enthused here is more interesting info. The magnetic and aucustic technology is fairly old hack, for more on magnetic search or read a book called THE QUEST FOR ABSOLUTE ZERO circa 1976ish. Also THERMAL SUPERCONDUCTORS on the net. I believe water may be the best refrigerant. I think it all started with a guy who saw condensation when a glass jar ruptured full of accetalyne which condensated then the dewer thermal vessal. David Hatcher childress wrote a book about free energy technologies including magnetic motors which provide cooling, ie they get cold instead of hot.
Other technologies to check out would be Vicktor Schouburger fluid flow technologies used for liquid line flow improvements. Electromagnetic and compressed air bearings have been around for decades.
So we have touched on mechanical, aucustic and magnetic cooling proccesses but I know the future is in LIGHT cooling technologies - just check out what temperature is in the core of a lightning bolt! I have over fifty inovative ideas for R&D but who has the money and who can you trust, just look at what happened to Nikola Tesla, Vicktor Schouburger, William Rieght, John Hutchison, and many others. Most of these technologies are kept for millitary black governments for fifty years or so then leaked if they think it's OK.
Mr frostedflake I work for Dalkia/Trane (Australia) and will be checking out what you posted - would you post a little more on these technology developements please.
Thanks

Thanks for the ideas.Indirect Direct Evaporative Cooling(IDEC) systems have very good scope in Climate zones are dry with high dry bulb temperature and low wet bulb temperature ,where you get good wet bulb depression for Cooling.
Places like Nashik, New Delhi and Nagpur such systems are used and it is effective and 100% fresh air, with excellent IAQ.
Dry bulb is 42 degree C and wet Bulb is 19 degree C with indirect cooling outside air is cooled to 30 to 32 degree C without adding moisture and then the air at 30 -32 degree C is passed over CELL DECK Pad for adiabatic cooling and thus you get close to 17 degree C which is distributed in the room / space. 80% of the air exhausted and balance 20 % through the door opening and closing as well as to keep pressurized.
with the above IDEC you save 60 to 70% compared to conventional Air conditioning

hie
i have just finished my advanced level 3 diploma in refrigeration heating and air conditioning,do you think i have a chance in getting a job in this industry

Quote:

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Originally Posted by simbarashe

hie
i have just finished my advanced level 3 diploma in refrigeration heating and air conditioning,do you think i have a chance in getting a job in this industry

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If you learn to ask the question in the right place then maybe.

I want to know out side design condition for NASHIk for all the season say summer, monsoon and Winter
for designing Aircondtioning system

Ronak, you better read first the Forum rules because nobody will response to your question.

Tesla please do go on about your theories on using light to cool. I have done a little bit of research on plasma and am now extremely intrigued in how to harness this energy.

Hi Koopy and thanks for asking the question.
There are 5 states of mater which only 3 were taught to me for my apprenticeship. Einstein/Bose condensate, solid, liquid, gas and plasma. The first and last are relatively new in development a good book of reference is The Quest for Absolute Zero (Mendelssohn). We first used solid to liquid phase change for cooling then liquid to vapor so it is only fair to assume that gas to plasma or plasma differential will be the next progression. There is a phenomena associated with lightning which is not well known. That is the center of the arc is something like over 50,000 Volts (commonly known) but what happens is the arc sucks energy from the surrounding air and cools even freezing it. I will try to find a reference on this http://www.climatechangematters.net....rms/storms.htm at the bottom under thunder. Not the best description of how it works but just an example, I initially read about it in a lightning book in 1994. Basically when the arc strikes a high pressure forms in the center and a low pressure on the outside - as we know about the pressure/temperature relationship when we reduce the pressure there is a cooling effect.
There are many areas of energy which we just don't know about and some that are kept secret like one of John Bedine Motors which cools instead of heating - down load Energy From The Vacuum (about 18GB) for a real insight or there's a few examples on utube (mxtube for iphones).
Then there are many areas which we know well about but haven't applied to refrigeration such as acoustic or ultrasonic to assist the evaporation process. Another example is Viktor Schauburger's fluid flow experiments which by the way someone else stole his ideas and patented it with a device used to reduce friction in the liquid line by creating a spinning vortex. We could apply this spinning vortex technology to other fluids we use such as air but we don't and why do we build square coils - there are no square fluid systems in nature, should we not build round coils in round ducts?
If you research you might even find our so called Laws of Thermodynamics don't hold true under certain conditions. In today's world with the internet a lot of the old ways of trying to keep us in the dark by silencing inventors and knocking them off just wont work. And just look at what wikileaks justice is doing for us. Please feel free to ask more.

Further on using light to cool.
If I quote from Roy J Dossat under Radiation pg 21 - "Light waves are radiant energy waves of such lengths as to be visible to the human eye. Thus light waves are visible heat waves." I have read that Tesla (the real one) could create a light with no source which could heat or cool a room but I can't remember where maybe a book by Margaret Cheney or David Childress. So the effect of using light for cooling is in nature and has been done before by man it just a mater of making a machine to efficiently do the job. I think the scientist in the lab will find it differcult to create such a device as they hold too strongly to classical physics, are brainwashed by their schooling and bound by their secret society groups. There is another phenomena where a lightning strike will prefer to track a low frequency laser pointed into the sky (so be careful pointing those green lasers into the sky) - Tesla Death Ray or Star Wars Project. There are also some who are working on controlling the plasma with vortex spin.
Some have created machines which are suspected of using zero point energy where cold is generated. I myself have seen on the protective glass on my little TV a large area of condensation during the first five minutes of switching it on however this may be a magnetic radiation cooling effect.
I imagine there are three way of progression 1, The scientist or inventor with funds plays with plasma, 2, The inventor plays with the Zero Point Energy technologies, 3, some other way I have not thought of or it could already be done but kept secret.
I think Buda says something like "An idea that is developed and put into action is more important than an idea that exists only as an idea." I hope to have started an action of this idea to be developed. But like many ideas not many make it, thankfully the turbo cor compressor made it even though it thought only half developed.