What is a refrigerated truck?
The refrigerated truck is a special refrigerated transport vehicle equipped with a refrigeration device and a polyurethane insulation compartment. It is often used to transport frozen food (freezer truck), dairy products (dairy truck), vegetables and fruits (fresh goods truck), vaccine drugs ( Vaccine transporter) etc.
What is the composition of refrigerated trucks?
The refrigerated truck is composed of the walking part of the special car chassis, the body part (composed of glass fiber reinforced plastic, color steel plate, aluminum alloy, stainless steel and other materials), heat insulation layer part (usually polyurethane), refrigeration unit part, temperature recorder, etc.
For vehicles with special requirements such as meat hook trucks, meat hooks, aluminum alloy guide rails, ventilation slots and other supporting equipment can be installed.
Manufacturing technology of refrigerated car body
Most of the large domestic refrigerated truck manufacturers adopt the “sandwich” board bonding technology of piece-by-piece assembly, and the inner and outer skins are made of composite materials, such as glass steel plate, color steel plate, aluminum alloy and other materials.
The material of the inner plate should be different for different goods. The most expensive inner plate should be stainless steel. The middle interlayer is made of thermal insulation material, mainly using polyurethane foam material.
The four sides use high-strength glue to glue the glass steel plate and the polyurethane foam material together to form a closed plate; there are also injection foaming type and integral frame injection foaming type assembled.
Different goods have different requirements for the body. For example, refrigerated trucks for transporting fresh meat need to be customized with hooks on the body; refrigerated trucks for distribution to stores require multi-temperature refrigerated trucks due to the small batch of goods and the variety of goods; for goods with different temperature requirements and frequent loading and unloading, You need to open more refrigerated trucks.
Refrigerator truck refrigeration unit and power source
The refrigerating unit of the refrigerated truck is generally installed on the top of the front of the container.
It has an air-conditioning-like appearance, but has a stronger cooling capacity than an air conditioner of the same volume. General models use external coolers, and a few miniature refrigerated vehicles use built-in coolers.
For refrigerated trucks with lower temperature requirements, a built-in cold plate can be used. Generally, refrigeration units with different power refrigeration capacities are selected according to the volume of the refrigerated compartment and the temperature requirements of the goods being transported.
The power source from the refrigeration unit can be divided into independent and non-independent units. The independent unit has a separate power source.
The difference is that the independent unit is completely powered by another unit to maintain its work; the non-independent unit is completely driven by the engine working power of the vehicle to drive the cooling work of the motor unit.
The use of refrigerated trucks
The use of refrigerated trucks should pay attention to the following points:
1. Before loading, the carriage must be pre-cooled or pre-heated for about 1.5 hours. Because the vehicle is parked in the open air, usually the temperature of the compartment is the temperature of the outside environment. After the goods are loaded into the compartment, the ambient temperature in the compartment will affect the temperature of the goods to be transported, which will lead to changes in the quality of the goods. Therefore, the compartment must be pre-loaded before loading. Cool to the necessary temperature.
2. The refrigeration unit must be turned off during loading and unloading. Many people do not turn off the refrigeration unit when loading and unloading goods. This is a very wrong operation. The principle is: when the car is pre-cooled, if the car is not shut down and the car door is opened, because the fan of the refrigeration unit evaporator is working, The front of the fan is positive pressure, and the back is negative pressure, so the cold air is blown out from the upper part of the car, and the lower part will quickly suck in the hot air from outside, which will cause the temperature in the car to rise rapidly; if you load and unload goods after shutting down, because the fan is in In the stopped state, the air flow stops, and the wind pressure inside and outside the cabin is the same, so that the speed of the external hot air passing into the cabin is relatively slow.
3. When using refrigerated trucks, keep the floor of the truck clean. Due to the action of the evaporator fan, air will circulate in the compartment, causing debris or dirt on the ground to be sucked in by the evaporator fan. Long-term action will cause a large amount of impurities to be sucked into the evaporator coil, thereby affecting the cooling effect of the refrigeration unit.
4. Appropriate packaging is essential to protect the goods. For frozen goods, non-ventilated packaging boxes should be used. Because the wind blows over the surface of the frozen goods, the moisture in the goods will be lost and the quality of the goods will decrease.
my country’s regulations on bulk quick-frozen foods are not allowed to be sold, and this is the reason why they must be sold in packaging; for fresh goods, packaging boxes with ventilated side walls must be used.
Due to its own characteristics, fresh goods are still breathing during storage and transportation. If they are not well ventilated, the goods will deteriorate and become damaged.
5. When loading, do not stack the goods too high, and make sure that the height of the loading is not higher than the plane height of the air outlet.
If the front of the air outlet is blocked by the cargo or too close to the cargo, it will not only affect the storage and transportation temperature of the cargo, but also affect the normal operation of the refrigeration unit.
Because if the air outlet is blocked by the cargo, the cold air cannot circulate normally in the compartment, which will increase the local temperature of the cargo.
On the other hand, some of the defrosting designs of refrigeration units use air induction defrosting, blocking the air outlet, which will greatly reduce the defrosting effect.
6. Double-sided pallets must be used for loading to ensure the circulation of cold air on the ground. It is strictly forbidden to stack goods directly on the flat floor; plastic film cannot be wrapped on the fresh-keeping pallet, which will block the circulating cold air flow to the goods.
How to maintain and repair the refrigerated truck?
The maintenance of refrigerated trucks is very important. Only the correct maintenance of the equipment on time can ensure the normal use of the equipment and prolong the service life of the equipment.
1. Generally, the refrigeration unit is maintained every 500h～700h, and the oil filter element, fuel filter element, and air filter element need to be replaced; and pay attention to check the tightness of the belt and whether there is leakage in the refrigeration system.
2. Daily maintenance of the refrigerated vehicle insulation compartment: inspection of the outer surface of the compartment, inspection of the inner surface of the compartment, inspection of the inner and outer edges of the compartment, inspection of the inner floor of the compartment, and inspection of the internal lighting and cooling air outlets.
3. Do not scratch the outer surface of the refrigerated car. On the one hand, it will reduce the ability of FRP to withstand pressure and be more prone to aging and deformation. On the other hand, it will leak the polyurethane filled inside and affect the insulation performance of the car.
4. The maintenance of the inner surface of the refrigerated truck should be adjusted by temperature control. Do not freeze the inner surface of the compartment.
If the air humidity is relatively high, try to pack the refrigerated products, especially if the aquatic product is packaged and sealed, it can reduce moisture to the compartment. Evaporates inside the body, reducing the possibility of icing inside the refrigerated truck.
