Refrigerated trucks are used to transport frozen or closed-Frontal fresh goods, is equipped with refrigeration unit refrigeration equipment and polyurethane insulated compartment refrigerated transport vehicle, commonly used to transport frozen foods (refrigerated trucks), dairy products (milk truck), fruits and vegetables (fresh produce truck), vaccines medicines (vaccines truck) and so on. Refrigerated trucks by walking part of the special vehicle chassis, with the insulation envelope (typically made of polyurethane materials, glass and steel composition, color steel, stainless steel, etc.), refrigeration units, the inside temperature loggers and other components for the special requirements of the vehicle, such as meat hooks car, the installation of the meat hook, down the middle, aluminum rails, ventilation slots and other attachments. Refrigeration unit is divided into non-independent refrigeration units and a separate refrigeration unit. Domestic and imported units, and other units. General models are used external cooler, a few mini-refrigerator car with built-in cooler. For lower temperature requirements refrigerated trucks, may take the built-in cold envelope (functionally equivalent to the evaporator). Sealing containers refrigerated trucks need to ensure strict sealing to reduce heat exchange with the outside world, in order to ensure refrigerated cabinet to maintain a lower temperature. Cooling of the installation of refrigeration equipment and containers connectivity and provide a steady stream of cooling, the temperature of the container to ensure that within the allowable range of goods. Portability general cargo transported by refrigerated trucks are not long-term storage of goods, although refrigeration equipment, still need to reach their destination faster. Refrigerated trucks insulation container similar to the container, but by better insulation material, reducing the heat exchange. Refrigerated truck refrigeration unit: provide a steady flow of containers for refrigerated trucks "cold" important equipment, usually at the top of the front of the container installation, air conditioning-like shape, but lower than the same volume of air conditioning has more cooling capacity. Refrigeration units are generally divided into two types, freestanding units and non-independent units, except that the unit is completely independent of one another through the power supply unit to maintain the work of non-independent unit is entirely driven by the engine power take off units of the vehicle Refrigeration is generally based on the volume of cargo and transport refrigerated envelope of temperature requirements to select different power cooling capacity of the refrigeration unit. Refrigerated truck refrigeration unit for temperature-controlled, and the role is to keep the envelope for temperature. If the refrigeration unit is energy provider, the envelope is the energy stored by. In the three major components of refrigerated trucks, refrigeration units and heat envelope is the most important, the removal of the chassis can be used as a small insulation, cold storage.