Heat or cold? Choosing an ideal refrigerator

25.06.2015

Usually people don’t think about how products, flowers and medicaments and others get the counters. But suppliers and entrepreneurs make lots of efforts to transport goods with particular temperature conditions of storage to their destination in ideal conditions. To transport these products they use trucks-refrigerators.

The word “refrigerator” comes from refrigero — «cool» or refrigeratus — «cooled» and in general means a vehicle for transporting perishable foodstuffs and other cargo requiring a special temperature mode. It concerns flowers, medicaments, household chemicals, vegetables, meat, dairy, fish, and confectionary and so on.

In the narrow sense a refrigerator is a refrigeration and heating unit (RHU), installed in the isothermal truck with the volume from 2 m3 to 120m3 and operating for keeping necessary temperature from -30 °С to +12 °С.

A lorry-refrigerator consists of chassis, an insulated body and a refrigeration unit. Technical characteristics of chassis determine carrying capacity. So for transporting in a city the carrying capacity can be up to 8 tons. If the transportation is not only in a city but also in a region, it’s necessary to choose chassis which provides goods transportation from 5 tons. However for international transportation they need tonnage refrigerators with the carrying capacity of 10 tons and even more. Nowadays a lot of big companies produce chassis for special vehicles. We are going to speak about the main marks of these technics and their advantages further.

An insulated body consists of inner and outer walls, there is some insulation between them. Nowadays insulated bodies are produced according the technology “sandwich”, that means that the insulation is glued between walls, that avoids heat bridge. The thicker the layer of insulation the better the truck keeps cold or heat. Besides the thickness of the insulation the material which is used for production of insulation is also important. Producers of insulated bodies usually use extruded polystyrene, polyurethane foam, styrofoam. It’s necessary to remark that the first two materials have a lower thermal conductivity and it means they are more suitable for insulation. From the way how the truck is insulated the guaranty period and the quality depend, because a refrigeration unit will just idle in a badly insulated truck.

What is a refrigeration unit like?

Then pay attention to a refrigeration unit, i.e. a refrigerator. A refrigeration unit consists of a compressor, a condenser, an evaporator and a control panel. The compressor is needed to compress refrigerant as in usual fridges.

Compressor can operate:

  • – from engine;
  • – from independent power source;
  • – from generator;
  • – from electricity.

At the time of switching on the temperature inside a refrigeration unit falls to -30 °C, and during all day the temperature keeps the same although rises a little, such a system is called eutectic. There are systems which work from a compressor, ran by an engine, and keep the set temperature up to -20 °С.

A condenser is necessary to remove the heat which is produced in the process of compressing of refrigerant.

An evaporator is a radiator which transforms liquid refrigerant into gas, taking heat from the ambience and cooling the space of the truck.

A control panel is to control and set a temperature mode and also for diagnostics and defrosting of the truck.

Depending on technical characteristics of a refrigeration unit and particular temperature conditions of storage and transporting of cargo there are 6 classes of refrigeration units:

  • Class А — the temperature mode in the truck is kept from 0 °C to +12 °C.
  • Class В — in the truck of this class the temperature is kept from -10 °C to +12 °C.
  • Class С – from -20 °C to +12 °C.
  • Class D — temperature is not more than 0 °C.
  • Class E — temperature is less or is -10 °C.
  • Class F — is not more than -20 °C.

Remark that for cargo transporting which requires a refrigeration unit, it’s necessary to take in consideration the coefficient of heat conductivity. (Coefficient К)

Coefficient K is an index which determines thermal insulation of an isothermal truck. According to international requirements the truck has an upgraded heat isolation, if coefficient K not higher than 0,4 Wt/m2* °С. Trucks with this index are recommended to use for transporting of frozen goods, i.e. with a refrigeration unit of class С. In this case if coefficient К is more than 0,4 Wt/m2*°С, but less 0,7 Wt/m2*°С, then this truck refers to class А and is for transporting of frozen goods. The trucks having the coefficient of heat conductivity more than 0,7 Wt/m2*°С, are not isothermal according to international standards that means there is no sense in installation of a refrigeration unit. Nowadays many companies producing lorries-refrigerators and components for refrigeration units are presented in Russian and International markets. But before we need to see in details producers of refrigeration units and their base models, learn some history.

The History of refrigeration units.

Our ancestors quickly understood that the products are kept better and stay fresh at low temperatures. That’s why our ancestors kept food in basements, cellars, glaciers. The problem of storage was solved quickly, but the problem of transportation was more difficult. American milkmen faced a very serious problem of turning milk sore quickly when the weather is hot. Their clients complained and refused paying money for this product.

Then drivers of milk trucks gave an idea to create a special small unit which can be transported or a portable fridge. It needed just to make a system of power supply for this unit and to create a truck, which can protect from influence of environment. American scientists started creating such a unit, that can be powered from a rechargeable battery of the vehicle, but also takes a little place in the truck. And in a few years the first refrigeration units for vehicles appeared. They quickly became popular and soon entered the international market. There appeared producers specialized in production of refrigerators of different models, which were focused on separate kinds of products and goods. Today there is a huge quantity of models of refrigerators. Then it’s necessary to remember lorry chassis, which are responsible for carrying capacity of a refrigerator.

Characteristics of lorry chassis and trucks for refrigerators.

Nowadays there are many companies producing chassis and isothermal trucks. In this article we won’t see in details chassis and trucks, we are going just to remain the most popular companies which produce them and have a good reputation in the market of specialized technics. The company HINO Motors is a part of the famous corporation Toyota Motor Corporation. This company is specialized in production of lorries and trucks, it also tries to combine quality and a good price on its product. The company HINO is widely presented in Russian market with a big quantity of lorry models. To 2013 the most popular model was HINO 300, the carrying capacity of the chassis is 7,5 tons. In 2013 the company HINO presents a new model of the truck HINO 500 with the carrying capacity from 12 to 17,5 tons, which has a rear air suspension. The company Hyundai is one of the most required automotive companies in Russian market of commercial technic, that produces a small isothermal truck and a refrigerator of high quality on a good price. This truck is quite comfortable for urban and suburban transport, has a powerful diesel engine, a power steering, fog lights and heated mirrors. The company Iveco is one of the leaders in the international market for design and production of commercial vehicles. The company produces high quality trucks and takes care of environment. And any truck of the company has a comfortable design of the van. The German company MAN Truck & Bus produces a truck-refrigerator with a high carrying capacity and maneuverability, that is especially convenient for cities. The vehicle has a low fuel consumption and a high driving performance. The concern Mercedes-Benz produces not only cars and heavy trucks, but also lorries with small carrying capacity. Today the company Mercedes-Benz has a wide range of models of trucks which meet all the needs. The Russian automobile corporation КАМАZ as a chassis producer for trucks, including refrigerators is also popular among Russian and foreign consumers. The technical characteristics of trucks КАМAZ meet the international standards and are quite competitive with foreign producers in the market of commercial vehicles. КАМАZ produces trucks with the carrying capacity 8 to 16 tons, and also more than 16 tons. Of course, these are not all the companies producing chassis and isothermal trucks which are presented in the Russian and foreign market, but only the most famous of them. If you are going to buy technic of this kind, you just need to pay attention to different models of refrigerators, compare their characteristics and make the best choice.

Choose a refrigeration unit

Today this market segment includes many companies that produce different kinds of refrigeration units and components. We are going to talk about three Russian companies — «Elinje», TerraFrigo and Global Freeze, which produce refrigerators. Each company offers a very wide range of models of refrigeration units. In this article we are going to compare refrigeration units for average tonnage trucks.

Let’s start with the Russian-South Korean production company Global Freeze, that is one of leading scientific-production plants that develops and produces refrigeration units in Russia and CIS countries. The company Global Freeze started production of refrigeration units in 2000. Since then the company has been constantly developing and upgrading produced equipment and its technical characteristics. Doing this the company tries to pay attention to all the needs of the clients and finally meets them. The refrigeration unit Global Freeze GF35 operates in the temperature mode “heat-cold” and is designed for transporting products as eggs, potatoes, sausage, dairy products, fish and canned goods, frozen goods, flowers. This model has modifications: Stand-by — driven from electromotor, a compressor is charged from outer electricity chain 220V/380V and truck heating up to +12 °С, an evaporator is flat and can be fixed to the front wall of the truck.

The production holding «Elinje» operates since 1993. Since 1996 the holding has started production refrigeration automotive equipment. The company «Elinje» produces refrigerator series «Elinje-С», «Elinje-Сt» «Heat-cold» and a range of multi-temperature refrigeration units. «Elinje» stands out among others similar companies in the market because it provides a wide choice of goods and services. It also has a wide chain of partners, about 100 companies in Russia and abroad, which provide services for company products. The company always develops its quality products and technologies.

The holding «Elinje» produces refrigeration units of class C, which keeps temperature mode from -20 °C to +12 °C. Company «Elinje» doesn’t recommend to install refrigeration units to isothermal trucks which have coefficient K not higher than 0,5 Wt/m2•°С. The refrigeration unit «Elinje С4» is designed for transporting cooled goods and deeply-frozen products in the cars of an average carrying capacity. A refrigeration unit consists of 2 systems: the first one is an operation system, the second one is a controlling system, both are connected in 4 blocks. Blocks of the refrigeration system are installed in different parts of the truck and are connected with electrical cables and Freon hoses. Model С4 can be freely installed on chassis of the following cars: МАZ, КАМАZ and HYUNDAI.

The factory TerraFrigo is a modern Russian company with the total area more than 7.000 m2, with own powerful production base – more than 80 machines of different specialization. Since 2004 the company has been developing and producing refrigeration units for commercial vehicles and refrigeration and heating units, automobile air conditioning systems and conditioning systems for special technics under the brand of TerraFrigo. The factory has the highest level of localization of production among Russian producers of refrigeration and heating units for commercial vehicles. The factory produces a wide model range of refrigeration equipment for keeping different temperature modes all year round.

The refrigeration unit S–30 is designed for transporting cooled and frozen goods, fruit and vegetables. This model has a flat evaporator that allows to keep constant volume of air flow in the truck even with maximum loading. S–30 can be installed on trucks Hyundai, Ford, Isuzu and so on. The refrigeration unit S–30 is designed taking in consideration the conditions of Russian roads and is highly durable. Most of components of refrigeration equipment is produced by the factory TerraFrigo, that provides a coordinated operation of all the components and proves high quality and long life service of a refrigeration unit.

Conclusion

All the models of refrigeration units mentioned above are designed for installation on average tonnage trucks, which are focused on transporting cargo in a city and in a region.

The presented models Global Freeze GF35, «Elinje С4» and TerraFrigo S–30 have similar characteristics. So buying one of them the client won’t lose. There are some differences concerning the mode of defrosting, the location of condenser, the volume of the truck- the comparative table can help to choose the best variant taking in consideration their technical characteristics. The cost of any of these models is not higher than 160 thousand rubles including packing. The other refers to customer personal preferences and his awareness of the mentioned marks; any of the 3 companies-producers of refrigeration units are well established in the market and offer a wide range of models of refrigeration units and services for them.

Source: ugspectehnika.ru