Thermoelectric refrigerator - a refrigeration device based on the use of the Peltier effect. The role of the working substance in heat transfer is played by direct electric current. Cold junctions of thermo-batteries are placed in a cooled environment, and hot outside.
The advantages of thermoelectric refrigerators are: the absence of liquid and gaseous refrigerants, moving and rubbing parts, quiet operation (not applicable to models with fans for dissipating heat from the thermopile), the ability to accurately control the temperature and heat capacity by varying the current value and reliability, stability under dynamic loads roll and vibration.
Thermoelectric refrigerators are widespread in vehicles.
What is a thermoelectric refrigerator?
There are three types of car refrigerators: compressor, thermoelectric and absorption. Each type is suitable for a specific situation and a car, but thermoelectric ones are universal, which deserve the trust of motorists.
The main principle of operation of a thermoelectric refrigerator is to pump heat energy from a refrigerator, isolated from the external environment. Thus, the temperature is lowered by the effect Peltier.
In such devices are present miniature metal modulesconsisting of cubes. They are interconnected by electricity and are located on the same physical level. Electricity passes through the modules, which displaces heat from one material and transfers it to another.
Solid state electrical modules may to transfer heat in large quantities. The principle itself is that heat is absorbed by a large cold metal plate. Energy moves from the material to the stabilizer, where it dissipates.
This design is located under the control panel of the refrigerator, where a small fan drives warm air, cooling it against the plate. The temperature when heated is 50 to 70 degrees, and a constant temperature in the summer about 10 degrees. After disconnecting the refrigerator from the mains, the temperature will be maintained about 10 hours.
Advantages of Thermoelectric Refrigerators
This type of refrigeration apparatus is widespread due to the advantages that its brothers do not have.
- Silent operation of the refrigerator. Typically, a device such as a refrigerator makes a lot of noise, causing discomfort. This type of refrigeration unit does not have this drawback and works silently. Taking it on a trip, you will not even notice that it is in your car.
- Lack of refrigerant. A refrigerant is a substance (liquid, gas, and even solid material) that is used to cool materials by boiling, evaporating, and circulating inside a cooling system. There is no refrigerant in thermoelectric refrigerators, which simplifies its operation.
- Low price. Refrigerators of this type have a low price in the market due to their simplicity and versatility. They are much cheaper than compressor ones, which makes them available to more customers.
- Shock and Shock Resistance. The design of such refrigerators allows safe transportation of food in the car. Shaking and hitting the device will not affect its work, which makes it indispensable for motorists.
- Reliability. Cooling units are complex structures. However, thermoelectric refrigerators are simple to install. They rarely fail, and if they fail, they are easy to repair and maintain. They have fewer parts that can be purchased in any city.
Disadvantages of Thermoelectric Refrigerators
Such devices also have disadvantages that affect operation.
- Weak cooling. Thermoelectric refrigeration units due to their device have such a disadvantage as poor cooling.
- Less food storage. Products in such refrigerators are kept fresh not so long as in other types of installations. That is why it is recommended to place already frozen or chilled food in thermoelectric refrigerators.
- Small volume. Typically, such refrigeration units have a small chamber size, which allows you to store not many products.
- Slow temperature set. Due to the unusual principle of cooling, such refrigerators gain operating temperature for a long time, which can be inconvenient.
- High power consumption. Refrigerators of this type have a low efficiency at a set temperature, which leads to a greater volume of electricity consumption. Due to the temperature difference inside and outside the unit, it is more difficult for her to gain a working norm.
How to choose a thermoelectric refrigerator?
Having decided to purchase this unit, you have a question “How to choose a thermoelectric refrigerator?”. Now we will give you the answer to this question.
You should choose a refrigerator according to three criteria:
- Temperature Range. Here it is worth choosing depending on operating conditions. You can purchase a freezer if you are in a hot climate.
- Travel duration. Depending on the length of your trips, you can choose small containers and bags for short movements, or buy larger and more powerful units if you plan to travel far.
- Volume. Here you already need to watch: you are traveling alone, or with family. If you drive alone, refrigerators with a capacity of 5 liters or more will suit you. You can put there food and drinks that you have enough for the trip. Or you can purchase containers with a capacity of 30-40 liters, if you are not alone.
Thus, we examined all the advantages and disadvantages of thermoelectric refrigerators. If you like long trips by car, then this type of refrigeration unit will be useful for you.
It is reliable, makes no noise, and is also convenient to use. We recommend putting already frozen and chilled food for a higher efficiency in the use of the refrigerator.
Despite its low volume, it is quite enough to preserve the freshness of food. It is easy to maintain and repair, since it has a minimum of parts, without refrigerant, and spare parts can be purchased in any city.
Advantages of car refrigerators
A big plus of thermoelectric refrigerators is a low noise level during operation. This is due to the lack of moving and shaking elements. Due to this feature, they are used not only for cars. Sometimes their installation is appropriate in an apartment, in the country, in a hospital ward. Compared to compressor and absorption devices, thermoelectric options consume much less electricity. Moreover, they rarely fail and are highly reliable, which means that you can avoid the additional cost of repairing them. Thermoelectric refrigerators are not afraid of shaking and vibration, which is why they are often used in cars.
Principle of operation
The principle of operation of devices of this type consists in pumping out thermal energy from a refrigerating chamber isolated from the external environment in order to lower the temperature in it. The process is based on the Peltier effect (pumping heat by electricity from a cooling device). The effect got its name thanks to the French scientist who made this discovery back in the 19th century. In devices of this type, modules are provided that consist of miniature metal cubes. The latter are interconnected by electricity and stored together on a physical level.
At the time the electric current passes through the cubes, heat is transferred from the source material to the new one. The solid state of the thermoelectric modules of the device is capable of transferring heat in a significant amount.
Temperature mode
The principle of operation of thermoelectric refrigerators is based on the fact that the absorption of heat from the products placed in it occurs due to a large cold plate. Thermoelectric modules move it into a heat-dissipating stabilizer. This component of the refrigerator is located under the control panel. In this area, a small fan dissipates heat from the cooling unit through the air.
The constant temperature of the refrigerator in hot weather ranges from 10 ° C. When heated, the temperature rises to + 54-70 ° C. After disconnecting from the mains, the temperature in the chamber may remain the same for 8-10 hours.
Usage Tips
The efficiency of such cooling is 16-17%, so thermoelectric refrigerators are not able to cool the products placed in them in a fast mode. The main function of this type of device is to keep food cool, rather than contribute to their cooling. If we compare them with isothermal containers, then the storage time of products in them is unlimited, since the device is continuously fed.
Before you start operating a thermoelectric refrigerator, you must first cool everything that will be stored in it. It is also necessary to allow the empty chamber to cool. Some models of car refrigerators have two operating modes. They can heat and cool foods. Due to the heating function, this refrigerator is the leader among compressor and absorption ones. If you know the device of thermoelectric refrigerators well, you can choose the most suitable model with a set of certain technical parameters.
When choosing an auto-refrigerator, you need to determine its location in the car and only then make a purchase. It is necessary to position the device in the car in such a way that direct sunlight does not fall on it. Since the thermoelectric refrigerator is slowly gaining temperature, it should be turned on before traveling in advance. You can go the other way - to cool the camera using cold accumulators. For this purpose, it is forbidden to use ice, because melt water will cause corrosion on the metal elements of the car refrigerator.
How to choose
As a rule, thermoelectric refrigerators for home and car cannot boast of a large capacity. Their volume is 0.5-50 liters. Budget models are able to function in cooling mode and exclusively from the on-board network. In expensive devices, a heating function and the ability to connect to a household network are provided.
When choosing a thermoelectric type refrigerator, it is important to determine the following parameters:
- Volume. An auto-refrigerator with a capacity of up to 5 liters is ideal for motorists who travel on their own. Such a device can accommodate a small number of products and bottles of drinks. If you intend to travel with the whole family or a large company, it is advisable to prefer a thermoelectric refrigerator, the volume of which will be 30-40 liters.
- Duration of travel. If the unit is needed for trips to the countryside or for movement at minimum distances, the best solution is to purchase an insulated bag or container.
- Temperature Range. If the refrigerator is to be operated in hot conditions and the temperature difference is significant, a freezer may be needed.
Reviews
If you refer to reviews of thermoelectric refrigerators, then the owners of such devices recommend that you follow these rules when choosing:
- To purchase a model with a protective device that will control the maximum permissible discharge of the vehicle’s battery.
- Give preference to refrigerators with a sufficient cord length (at least 2 m).
- Choose a device with a secure lid.
