Monthly Archives: September 2015

Beer Cooler – Thermoelectric

Whether in Summer or the other seasons, a drink of beer is really refreshing .You might enjoy it at home or on the go hijacking ,camping ,after sport event , after a hard day of mountaineering or when you  have to go to work on a job in remote sites, any where a bottle or can of  cool beer is soothing and relaxing.

Have you ever met any body that enjoy a drink of beer warm! well I haven’t for the past sixty years of my life.

It is time to get to our main subject! The modern beer coolers. So what is a thermoelectric or some like to call it thermal beer cooler, it is a refrigerator (non freezing) constructed using the Peltier effect which state that when two pieces of metal wires connected from one end supplied with electrical source, one side becomes hot and the other cold. Developments and research added to that principles by using solid state semiconductor materials to replace the wires, then fabricated into single module called TEC (thermoelectric cooler) module. Since the module which is the heart of the cooler (refrigerator) is small , the overall size and weight of the beer cooler is usually small and light weight compared with the same capacity conventional refrigerator which use compressor.

Advantages of Thermoelectric Beer Cooler

  1. completely quite since it has no moving part.
  2. small and light weight and some easily fit into back -bag.
  3. Very durable since it uses solid state module.
  4. Works indoor and outdoor using battery supply such as car cigarette lighter socket and with adapter indoor from 110/220 volts mains supply.
  5. Keep beer and wine as cool as desired to a temperature adjustable down to about 5 degree Celsius.
  6. Needs none or little maintenance.
  7. Prices are reasonable depending on capacity and compared to conventional coolers.

How to Select the Right Beer Cooler

Big variety of suppliers and capacities are available in the market online and in stores.     So it might be a difficult choice to make, given that there are many beer coolers out there. But, there are a few things you need to consider before you make a decision, like the size and shape? Think about  the purchase of a beer cooler that is a little bigger than you require, as sometimes you won’t know exactly when more people will attend a gathering or invitation that you made which could be an embarrassing situation not to have enough beer for everybody.

Also decide whether you need a bottle or can beer cooler and where you need it, out door such as camping ,while travelling , when fishing or only for indoor use. Also decide the size and capacity.

A good variety of makes, sizes and capacities are listed in a priced list in our Store page.

If interested for more information, please check each to read detailed reviews of many people that purchased some of them. Most of coolers listed are suitable as beer and wine coolers. also available are can beer and draft beer coolers.

 

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Environmentally Friendly Thermoelectric Power Generators

Electricity generation in most countries depend mainly on turbine driving combustion engines and account for about 90% of the generated  electricity world wide.

These systems operate at an efficiency of around 35% so the rest of the input energy is lost as waste heat. Progress in using thermoelectric high power generators was very slow in the past due to poor electrical and thermal properties of the materials used to produce the TG modules which are the main part of thermoelectric generator, this situation continued to be true for many decades . Luckily the situation has changed since the start of this century as researchers in universities and industry started to experiment with many materials that has more suitable properties and some research results indicate that figure of merit of about 2.0 has been achieved (figure of merit determine the usability of the material to produce the modules)  leading to the production of thermoelectric modules having an efficiency of over 10%.

It is well known for decades that  thermoelectric devices are superior in many respects , so with the improvement in efficiency, they are getting now more popular as power generators.

Some companies has actually started producing thermoelectric power generator with an out put electrical power of 25 KW, this can be used in manufacturing plants, oil and pipeline sites, electrical power plants and in marine vessels to convert waste heat power to useful electrical power which could account to extra power of about 20% that was other wise wasted. I consider this as a substantial improvement .

In automobile industry, many car companies has actually started few years ago experimenting to use the wasted fumes out of the exhaust pipe in their vehicles to convert into useful electrical power in order to increase the fuel efficiency of their automobiles , some of these companies has in fact succeeded in doing so by feeding the fumes to thermoelectric solid state module which convert input heat into useful electrical power. Some claim that they managed to decrease fuel consumption of their vehicles by about 15%. In this way wasted heat has added extra useful power and helps to protect the environment in the same time. Perhaps these high power generators with no moving parts , highly reliable and mostly free of faults will help to reduce electrical power shortage in underdeveloped countries especially in remote locations.

 

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Efficiency of Thermoelectric Devices

Nowadays there are many alternative power sources and for thermoelectric generators and coolers to be competitive , their efficiency has to increase from the value which is attainable now (about 10%) .

Efficiency of thermoelectric devices is mainly determined by the properties of the semiconductor materials used to manufacture the modules called in abbreviation-TE- modules. One module is used to produce low power devices while many connected in series is needed to produce high power devices. The properties of these semiconductor materials determine how effective they are to produce poor or good efficiency, the effectiveness is called figure of merits (Z) which depend on Seebeck coefficient (s), electrical conductivity (σ), and thermal conductivity (k) according to the formula

                   Z = σS2
                           
  k

The formula indicates that a good thermoelectric module should have a high electrical conductivity and Seebeck coefficient as (electric crystal) and low thermal conductivity as a (phonon glass).

Figure of merit Z has only increased from 0.6 to about 1.0 over the last five decades and research indicate that for thermoelectric devices to be competitive for high power applications, the figure of merit need to be about 3.0.

The variables in the above formula which are mainly the electrical and thermal conductivity interact with each other in reality and so it is very challenging to produce a module that has a high electrical conductivity and in the same time low thermal conductivity .

Latest laboratory research is concentrating on experimenting with many different materials to reduce the thermal conductivity and reports indicate that it is possible now to get figure of merit of about 2.0 .

Some manufacturers specialize in production of thermoelectric devices claim that they have produced new generation of these devices using newly developed materials with comparatively high Z.

In conclusion it is quite clear that efficiency of thermoelectric devices is not expected to be any where near that of mechanical compressors or pumps (40% to 50%) in the near future but continuous improvement is expected.

It is worth noting that efficiency is not the only important factor in determining the use of thermoelectric generators and coolers but one needs to take into consideration the many advantages of thermoelectric devices in such location as for example using coolers by trucks and automobile users where portable devices are necessary and also while in a picnic or in  remote locations that require only low power devices and when reliability is a priority.

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