The external heat exchange system consists of the following systems.

1) Cold Chen water circulation system
The chilled water circulation system consists of a refrigerating pump and a chilled water pipe. The chilled water flowing out of the freezing main unit is pressurized and sent to the chilled water pipe by the refrigerating pump, and the heat in the room is taken away by the coil of each room, so that the temperature in the room is lowered. At the same time, the heat in the room is absorbed by the chilled water, causing the temperature of the chilled water to rise. The circulating water whose temperature has risen becomes frozen water after being frozen by the main engine, and this cycle is endless. The chilled water pipe that flows out of the freezing mainframe (into the room) is called “water outlet”, and the chilled water pipe that flows back to the freezing mainframe after passing through all the rooms is called “backwater”. Undoubtedly, the temperature of the return water will be higher than the temperature of the water, forming a temperature difference.

2) Cooling water circulation system
The cooling pump, the cooling water pipe and the cooling tower constitute a cooling water circulation system. The cooling main unit exchanges a large amount of heat while the water temperature is being cooled, and the heat is absorbed by the cooling water to raise the temperature of the cooling water. The cooling pump presses the warmed cooling water into the cooling tower to exchange heat with the atmosphere in the cooling tower, and then returns the cooled cooling water to the cooling unit. This cycle continues, taking away the heat released by the freezer.