For Chongqing refrigerated truck owners, understanding how to choose, use, and maintain refrigerated trucks is crucial. This article points out the key points of choosing a refrigerated truck and introduces how to perform daily maintenance on the key components of the refrigerated truck - chassis, refrigeration unit, and compartment, which can help car owners reduce unnecessary troubles in the selection and daily maintenance of refrigerated trucks.

1、 Key points for choosing refrigerated trucks

Refrigerated trucks mainly come in two forms: bicycles and trailers. For vehicles used for short distance delivery or loading of goods between urban areas and districts, refrigerated trucks with medium and light truck chassis can be selected.

When engaged in long-distance transportation, if the transportation volume is large, medium and heavy-duty vehicles or refrigerated trucks in the form of semi trailers need to be selected. The main components that affect the performance of refrigerated trucks are the chassis, insulated compartment, and refrigeration unit. Only when the quality of these three parts is up to standard can the refrigerated truck reliably and stably perform during transportation.

Compared with ordinary truck chassis, choosing a refrigerated truck requires careful consideration of the stability of the chassis. The goods transported by refrigerated trucks are usually items that cannot be stored for a long time and need to be delivered to the destination in a shorter period of time.

Refrigerated goods have higher requirements for transportation environment. If there is a malfunction during transportation, the delay time will cause the goods to deteriorate and result in losses. Therefore, when choosing a refrigerated truck, a light truck chassis can be chosen for short distance transportation, and a medium to heavy truck chassis or a tractor semi-trailer chassis should be chosen for medium to long distance transportation or large transportation volume.

At the same time, the advantages of imported car chassis are low maintenance rate, good handling, and fuel efficiency, but the price is high. The advantage of domestic car chassis is that it is cheap, but there are more minor problems. Therefore, when selecting a car chassis, users need to comprehensively consider the structure and load-bearing capacity of the chassis based on factors such as cargo tonnage, road conditions, and personal strength

The body of a refrigerated truck is different from that of a regular box truck, requiring good insulation and sealing performance to ensure that the refrigerated goods are in a stable temperature environment during transportation.

The choice of compartment is related to the specific goods being transported, for example, refrigerated trucks transporting fresh meat need to customize hooks on the compartment; When delivering goods to stores, small batches and a variety of goods require refrigerated trucks with multiple temperature layers.

When temperature requirements vary and loading and unloading are frequent, refrigerated trucks with multiple doors are needed. Users can customize the cabin manufacturing factory according to their specific needs. Of course, the cargo box of a regular box truck can also be converted into a refrigerated container, but it is not recommended to use a regular cargo box to convert into a refrigerated container.

In fact, using a refrigerated compartment directly is cost-effective because the cargo compartment is usually made of iron or steel, which has poor insulation effect and is prone to rusting. If seafood products are pulled, seawater will corrode the compartment. But regular refrigerated carriages have air tightness and insulation, usually using a three-layer structure, with composite materials such as fiberglass, color steel plates, aluminum alloys, etc. for the inner and outer skin.

The material of the inner plate varies depending on the transported goods, usually stainless steel plate; The intermediate layer is made of insulation material, mainly polyurethane foam material; High strength adhesive is used on the four sides to bond the glass plate with polyurethane foam material, which is not easy to rust.

In the selection of refrigeration units, non independent refrigeration units are cheap and easy to maintain, but they do not have a power unit and rely on the car engine to drive the compressor. Due to the influence of the working condition of the car engine, their performance is not as good as independent units.

The independent refrigeration unit itself has an engine and generator device that can provide power and electrical energy for the refrigeration system. It can work independently and is not limited by the working state of the car engine. The performance is relatively stable, but the price is high and the accessories are expensive.

Therefore, when selecting a unit, the length of transportation distance should be considered comprehensively. For short distance delivery within the city or between districts and counties, and if the carriage is less than 7 meters, it is recommended to use non independent units. When conducting long-distance transportation and the carriage is over 7 meters long, it is recommended to use an independent refrigeration unit. This way, even if the car engine stops working during transportation, the refrigeration unit can still cool normally, reducing the quality loss of the transported goods.

2、 How to use refrigerated trucks correctly

Only by using and operating refrigerated trucks correctly can the goods be transported and stored in good condition. A qualified refrigerated truck should ensure good ventilation conditions on all six sides of the compartment and no obstacles.

Because good air circulation is a key element in ensuring the appropriate temperature of goods. The quality of goods can only be protected when the cold (hot) gas blown out by the freezer isolates the external cold (hot) source entering the carriage from the goods.

If there is a blockage in a certain position inside the compartment, the cold (hot) source of that part will directly enter the goods, causing a change in the temperature of the goods. At the same time, it is necessary to ensure that the return air shutter is in good condition and not blocking the inlet of the evaporator (return air). Insufficient return air can cause irregular circulation of cold air, resulting in inconsistent temperature inside the compartment and freezing of the top cargo

When loading the refrigerated truck, the goods should not be stacked too high, and the loading height should not be higher than the plane height of the air outlet. Because if the air outlet is blocked by goods or too close to the goods, it will not only affect the storage and transportation temperature of the goods, but also affect the normal operation of the freezer.

Due to the blockage of the air outlet by goods, the cold air (or hot air) cannot circulate normally in the carriage, resulting in a local increase in temperature of the goods. On the other hand, due to the defrosting design of the freezer using air induction defrosting.

When the goods are too close to the air outlet, the coils inside the evaporator of the unit will quickly frost (or ice), and the air sensing switch will immediately operate. The unit will quickly enter the defrosting state, and when the temperature rises to 9 ℃, defrosting will immediately end. This cyclic defrosting operation will cause the temperature inside the compartment to not drop, increasing equipment wear and tear.