Refrigeration trucks are designed to carry various types of perishables, such as fruit, meat, pharmaceuticals, art, wine and even organs at specific temperatures. Most trucks or vans are fitted with special cooling systems and apparatus that allow for refrigerated transport of most goods.
The main goal of refrigeration systems is to remove heat and maintain a constant, pre-determined temperature. Most of these are closed systems and require three major parts to ensure that the correct temperature is kept.
The compressor is normally driven by a very small engine that helps it draw gaseous refrigerant in. The gas is then liquefied and begins to give off heat. This heat is responsible for warming up the compressor which in turn warms the air.
The condenser is a heat exchanger that works by transferring the warmth from the condensed liquid gas to the walls or fins of the tubing. The fins help by presenting more surface area for cooling. Air is brought into the condenser through a fan.
The evaporator is normally located inside the trailer. The main component of the evaporator is the metering valve. The cool compressed liquid flows through the valve, which controls the amount of refrigerant that is discharged into the evaporator.
The refrigerant expands in the evaporator and quickly turns back into gas. The result of this is that this now draws heat from the fins. The fins help transfer heat from the flowing air over the refrigerant and then the air from inside the truck is blown back over the evaporator. The gas is then pulled back into the compressor and starts the entire process again.
Maintaining the trucks to the highest standard is critical. Regular checks and testing to ensure that the cooling system is fully functional must be undertaken to avoid any costly disasters.