company news about The refrigeration principle and method of refrigerated truck

1, water ice and salt ice refrigeration:
Water ice refrigeration equipment less investment, low operating costs, but ordinary water (salt) ice per unit mass of heat absorption is small, the temperature in the carriage is limited, and salt ice melting will pollute the environment, food, corrosion of the carriage and value of goods damp, so water (salt) ice refrigeration is mainly in fish and other aquatic products refrigerated transport.

2. Dry ice refrigeration:
The device is simple, the investment and operation cost is low, the use is convenient, the goods will not be damp. The CO2 gas produced by the sublimation of dry ice can inhibit microbial reproduction, slow fat oxidation, and impair the respiration of fruits and vegetables. However, dry ice sublimation is easy to cause frost, and too much CO2 gas will lead to breathing difficulties and necrosis of fruits, vegetables and other refrigerated objects. Moreover, the temperature in the chamber is difficult to adjust, the cost of dry ice is high, and the consumption is large, so the practical application is less.

3. Cold plate refrigeration:
The device itself is heavy and large, occupying a certain volume of the carriage, and the cold plate can only work for 8~15H at a time. Therefore, cold plate refrigeration is suitable for medium and short distance transportation of medium and light refrigerated vehicles. In recent years, with the increasing prominence of energy and environmental pollution, the application of cold plate refrigeration has developed rapidly, and it has become second only to mechanical refrigeration.

4. Liquid nitrogen refrigeration:
The device has simple structure, reliable operation, no noise and pollution; Liquid nitrogen refrigeration capacity, rapid refrigeration, suitable for quick freezing. The vaporization of liquid nitrogen will not cause moisture in the chamber, and nitrogen is good for food preservation and preventing dry consumption. In addition, liquid nitrogen refrigeration temperature control is accurate (plus or minus two degrees). However, the high cost of liquid nitrogen requires frequent filling, so the promotion is limited. Similarly, other low-temperature vaporized liquid gases can also be used as refrigerants, such as liquid carbon nitride.

5. Mechanical refrigeration:
Mechanical refrigeration methods include steam compression, absorption, steam injection and so on. At present, vapor compression is the most widely used. Compressor refrigeration unit is mainly composed of compressor, condenser, throttle valve (or expansion valve) and evaporator.