1. The refrigerator can reduce the temperature of the goods to the minimum temperature of the refrigerator.
The function of the refrigerated truck box is to keep warm, and the function of the refrigerator is to ensure that the temperature of the goods in the box remains unchanged, and the temperature of the goods cannot be guaranteed to decrease.
For example, some customers who pull meat directly put the meat of the animal that has just been slaughtered into the box, and the temperature of the refrigerator cannot be lowered.
The refrigerator can easily cool down the temperature of the air, but it is difficult to cool down the temperature of the cargo, because the specific heat value of the cargo is close to 1000 times that of the air.
2. Goods with low temperature are difficult to cool down, while goods with high temperature are easy to cool down?
The temperature of the ice cream is controlled at -18 degrees, and this temperature is easy to drop. On the contrary, Mengniu's probiotic milk, as well as fruits, vegetables, and yeast, it is difficult to cool down the temperature of items that produce heat by themselves. When the temperature of the box is lowered, the temperature of the goods does not necessarily drop. For Mengniu's probiotic milk, the temperature in the probiotic cup can be controlled at about 4 degrees only when the temperature of the box is controlled at about -4 degrees.
3. The less the goods, the better the temperature to cool down?
The less the cargo, the larger the air volume in the box, which is one of the reasons why the temperature of the general probiotic milk is difficult to cool down.
a. Half-cargo, the volume of air is too large.
b. The goods themselves fermented to produce heat.
4. The temperature on the display of the refrigerator does not reach the temperature required by the goods, and the refrigerator is playing a negative role.
When the ice cream leaves the warehouse, the temperature is -18 degrees. After packing, the refrigerator is turned on, and the display temperature is 2-3 degrees, or even 7-8 degrees, which is the temperature of the air in the cargo box. As the cooling continues, the temperature of the display is also decreasing. Some refrigerators can reach -18 degrees, and some refrigerators can not reach -18 degrees, such as -13 degrees, and there is no problem with the quality of the goods.
5. The temperature of the refrigerator display is rising, which proves that the temperature of the goods is rising.
The temperature of the display only represents the temperature of the air between the packages in the box, not the temperature of the goods. The specific heat value of the air is very low, which can easily cause the temperature to rise, but does not mean that the temperature of the goods increases.
6. The larger the cooling capacity of the refrigerator, the better.
The advantage of a large cooling capacity is that the cooling rate of the box is fast, the pressure in the compressor system drops quickly, and the horsepower of the engine is consumed less.
However, the disadvantage is that the power consumption of the battery is relatively large, and the battery often loses power and cannot start a fire, especially for diesel vehicles. Therefore, the best principle for installing a refrigerator in a refrigerated truck is to match the appropriate cooling capacity.