What is the cooling principle of refrigerated truck?
the cooling principle of refrigerated truck
refrigerated truck are a special vehicle, also known as food preservation truck, which are mainly used to transport various foods, fruits, meat,refrigerated truck and so on. The refrigerator is based on the refrigerated insulation box installed on the chassis of the vehicle and the refrigeration unit is installed to achieve refrigerated and freezing transportation vehicles. So what is the cooling principle of refrigerated truck?
There are many ways to refrigerate the refrigerator. The following 5 are commonly used cooling methods:
1.Water ice and salt ice refrigeration: Water ice refrigeration device has less investment and low operating costs, but the quality of ordinary water (salt) ice units is small, and the cooling in the carriage is limited. Foods, corrosive compartments and value goods are moisture, so water (salt) ice cooling is mainly used for refrigerated transportation of aquatic products such as fish.
2.Dry ice refrigeration: simple installation, low investment and operating costs, convenient use, and not moisture.
The CO2 gas generated by dry ice can inhibit microbial reproduction, slow down fat oxidation, and weaken the breathing of fruits and vegetables. However, dry ice is easy to cause frost. Too much CO2 gas will cause refrigerated objects such as fruits and vegetables to breathe difficulty and necrotic. In addition, the temperature in the compartment is difficult to adjust, the cost of dry ice is higher, and the consumption is large, so the actual application is less.
3.Cold plate refrigeration: The device itself is heavier and large,refrigerated truck occupying a certain volume of the carriage, and the cold board is over 8~15h. Therefore, refrigerated truck cold board refrigeration is suitable for medium and short distance transportation of medium and light refrigerated truck. In recent years, with the increasingly prominent problems between energy and environmental pollution, the application of cold plate refrigeration has developed rapidly, and it has become a refrigeration that is second only to mechanical refrigerated truck after mechanical refrigeration. Way.
4, liquid hydrogen cooling: simple device structure, reliable work, no noise and pollution; large liquid nitrogen refrigeration volume, rapid refrigeration,refrigerated truck suitable for quick freezing. The vaporization of liquid nitrogen will not cause the tank to moisture, and hydrogen is good for food preservation and preventing dry consumption. In addition, liquid hydrogen cooling control is accurate (two degrees of positive and negative). However, the cost of liquid nitrogen is high, and it needs to be charged frequently, so promotion is limited. Similarly, other low -temperature vaporized liquid gases can also be used as refrigerants,
such as liquid dihydrogenated carbon.
5.Mechanical refrigeration: Mechanical refrigeration methods include steam compression, absorption, steam injection, etc. At present, refrigerated truck steam compression applications are the most widely used. The compressed refrigeration unit is mainly composed of compressors, condenser, throwing valve (or expansion valve) and evaporator.
Note: The inside of the refrigerator must be kept clean. Show properly. The correct operation can ensure that the goods are stored and transported in a good state. Preventive maintenance can minimize maintenance and operation costs.refrigerated truck Appropriate packaging is essential for protecting goods. Set the temperature controller on the required temperature, and the refrigerated truck is 1.5 hours to discharge the heat to stay in the box; turn off the freezing unit when loading, and quickly load the goods. The goods must be cold to the required temperature, check the temperature of the goods when loading; the freezing unit is used to maintain the temperature of the goods, not to reduce the temperature of the goods. Even if the unit capacity exceeds actual needs, insufficient air circulation will be the main cause of the deterioration of the items.