Key Technologies for Maintaining Low Temperatures in Refrigerated Trucks

The key technology for maintaining low temperatures in refrigerated trucks is to keep the temperature inside the compartment within a reasonable range, usually between -18°C and 5°C. The core technology lies in the refrigeration system. There are two main types of refrigeration systems: mechanical compression refrigeration and absorption refrigeration. Mechanical compression refrigeration is common in most refrigerated trucks because it is more efficient and can quickly lower the temperature inside the compartment. Some cold chain logistics companies have refrigerated trucks that can reduce the temperature from room temperature to -20°C within 30 minutes.

Refrigerated trucks are equipped with high-precision temperature sensors that can monitor temperature changes inside the compartment in real-time. The accuracy of the sensors is crucial; if the accuracy is not high, the temperature may fluctuate, leading to damage to the quality of the goods. The sealing of the compartment is equally important. Those "thick" refrigerated truck compartments use double-layer insulation materials, some of which are also equipped with polyurethane foam with a thickness of about 100mm. Heat is kept out, and cold air is not easily leaked, improving the refrigeration effect by at least 15%.

The refrigeration system must also remain continuously operational; if it stops, temperature fluctuations may occur. Some refrigerated trucks are equipped with dual power systems; if the main power fails, the backup power will take over immediately. This process may take only a few seconds, but it ensures that the refrigerated truck can maintain low temperatures at all times.

Impact of External Environment on Refrigeration

When the external environment temperature is high and the internal temperature of the compartment rises rapidly, loss of control can easily occur. Drivers must take emergency measures, including increasing the power of the refrigeration equipment or even parking the truck in a shady area to reduce the impact of direct sunlight. Adding an additional layer of 50mm thick polyurethane foam insulation on the outer layer of the compartment can reduce temperature fluctuations by 15%.

When the external temperature drops below -10°C, the internal temperature of the compartment may become too low, especially when transporting refrigerated foods. Drivers must reduce the power of the refrigeration equipment or even temporarily shut down the refrigeration system to prevent the internal temperature from dropping too low. When the refrigerated truck is in motion, the increased air circulation helps to maintain low temperatures inside the compartment.

However, once the truck stops, the temperature rises rapidly, especially in high-temperature environments. Parking in a shady spot can reduce a lot of trouble. Some companies have also used reflective coatings, which can reflect more than 90% of solar radiation, effectively reducing the absorption of external heat.

How Regular Maintenance Ensures Refrigeration Performance

Without regular maintenance, the refrigeration system will quickly develop problems, especially for refrigerated trucks that are constantly on the road. A comprehensive inspection of the refrigeration system every few months can ensure that the temperature inside the compartment remains within the set range.

If the condenser accumulates dust and dirt, the heat dissipation effect will be greatly reduced, leading to lower refrigeration efficiency. If the amount of refrigerant is insufficient, the refrigeration effect will undoubtedly suffer. Causes of insufficient refrigerant may include leakage, evaporation, and so on. Checking the amount of refrigerant every three months is essential, and if a shortage is detected, it must be replenished promptly.

If the seals are aged or damaged, cold air will escape directly. Replacing the seals is not costly but can reduce cold air loss by 20%. Regularly check the operation of the compressor, listen to the sounds, measure the temperature, and repair any issues.

Emergency Handling of Abnormal Temperature Situations

The temperature control system monitors temperature changes inside the compartment in real-time. If the temperature starts to deviate, the sensors will issue an alarm. Sometimes, the problem lies with the compressor. The compressor is the core part of the refrigeration system; if it fails, the temperature will undoubtedly be affected.

The solution is to stop the truck, shut down the compressor, and switch to the backup power system. This emergency operation may take only a few minutes, but it can buy valuable time for repairs. Suppose the entire refrigeration system suddenly fails, and the internal temperature of the compartment begins to rise rapidly. In that case, drivers will manually adjust the system, switching the refrigeration equipment from energy-saving mode to full-power mode.

Experienced drivers will use dry ice stored in the truck to buy more time for repairing the refrigeration system. In case of abnormal temperature situations, park the truck in a shady area to avoid direct sunlight. Some companies have also installed sunshades on the roof, which can effectively reduce the temperature inside the compartment.

Suggestions for Improving Compartment Insulation

Insulation materials for the compartment are crucial. The most common is polyurethane foam, which, when 50mm thick, can reduce heat transmission by 15% to 20%. Applying a reflective coating on the outer layer of the compartment can reflect more than 90% of solar radiation.

The door seals of the compartment are also critical. If the seals are aged or damaged, cold air will escape directly. To enhance insulation, some manufacturers have installed insulation curtains inside the compartment. These can divide the compartment into multiple temperature zones, especially when the doors are opened and closed multiple times, effectively reducing cold air loss.

Maintaining cleanliness inside and outside the compartment is also an important factor in improving insulation. Excessive dust accumulation can affect the effectiveness of insulation materials. Regular cleaning and inspection of the insulation layer for damage can help identify and repair issues promptly.