When using the transport refrigeration unit, because the vehicle is parked in an open space, the transport refrigeration unit must first pre-cool or preheat the workshop when loading. The usual workshop temperature is the ambient temperature. If the temperature of the goods being transported is not the ambient temperature, the workshop will be installed, and the ambient temperature will affect the temperature of the goods being transported, resulting in a change in the quality of the goods transported by the transport refrigeration unit. Because the transport chiller must pre-cool the workshop to the required temperature before assembling the cargo. However, when loading (unloading the same), you must turn off the refrigeration unit. Many people do not close the refrigeration unit when loading and unloading the goods. Originally this was a rather erroneous operation.
The reason is that when we pre-cool the transport refrigeration unit, if it is not shut down, when opening the shop door, because the fan of the evaporator of the refrigeration unit of the transport refrigeration unit is working, the opposite side of the fan is positive pressure, and the opposite side is negative pressure. Therefore, the cool air is blown out from the upper part of the workshop, and the lower part will quickly suck in the outside hot air, which causes the temperature in the workshop to rise rapidly. If the goods are loaded and unloaded after shutdown, the air flow stops due to the fan disposal stop mode, and the wind pressure inside and outside the workshop As a result, the speed at which external hot air is transferred into the workshop is relatively slow.
