Three Cooling Methods Of Cooler Cart

    There are three cooling methods for cooler carts. The actual working methods and advantages and disadvantages of these three methods will be briefly explained, which can help you understand the cooling principle of refrigerated vehicles.

    Water Ice and Salt Ice Refrigeration

    At atmospheric pressure, the melting point of ice is 0°C. The endotherm of ice melting is 334.8kJ/kg. Adding salts to water ice can lower its melting point. Within a certain range, the more salt in the water ice, the lower the melting point. Salt ice of different compositions is usually selected according to the suitable temperature for the transportation of refrigerated goods. The water ice refrigeration device has less investment and low operating cost, but the heat absorption per unit mass of ordinary water (salt) ice is small, and the cooling in the car is limited. In addition, after the salt ice melts, it will pollute the environment, and food, corrode the carriage and get wet. Therefore, water (salt) ice refrigeration is mainly used in the refrigerated transportation of fish and other aquatic products.

     Dry Ice Refrigeration

    Under one atmospheric pressure, the sublimation temperature of dry ice (solid carbon dioxide) is low (-78.9°C), and the sublimation heat absorption is large (573.5kJ/kg). at -20°C), and a larger cooling capacity can be obtained. Therefore, this refrigeration method is suitable for the transportation of frozen food.

    A dry ice refrigeration device is simple, has low investment and operating costs, is easy to use, and the goods will not be affected by moisture. The carbon dioxide gas produced by the sublimation of dry ice can inhibit the reproduction of microorganisms, slow down fat oxidation and impair the respiration of fruits and vegetables. However, the sublimation of dry ice is easy to cause frost; too much carbon dioxide gas will lead to breathing difficulties and necrosis of refrigerated objects such as fruits and vegetables; the temperature in the compartment is difficult to adjust; the cost of dry ice is high, and the consumption is large, so the practical application is less.

     Cold Plate Refrigeration

     The principle of cold plate refrigeration is to use the cold energy stored by the cold storage agent (refrigerant) for refrigeration. Before transportation, "charge and cool" the refrigerating agent in the cold plate in the compartment to make it cool and freeze, and then use the refrigerating agent in the cold plate to melt and absorb heat during transportation to keep the temperature in the compartment within the suitable temperature range of the transported goods. Therefore, the cold plate is also called the "cold storage plate".