Pipe-in-pipe cooling system

The invention discloses a pipe-in-pipe cooling system. The pipe-in-pipe cooling system comprises a cooling unit, wherein the cooling unit comprises a water collection disc, a cyclone pump, an outer pipe, an inner pipe and an air cover; the outer pipe spirally ascends to form a cylindrical air pipe; the inner pipe spirally ascends to form a cylindrical cooling pipe; the air cover covers the water collection disc and then wraps the cyclone pump, the air pipe and the cooling pipe inside; the air outlet of the cyclone pump communicates with the air inlet of the air pipe; a plurality of nozzles are fully distributed in the cylindrical outer circumference of the air pipe; the cooling pipe is located in the air pipe; a heat exchange space is formed between the circumference of the outer cylindrical surface of the cooling pipe and the circumference of the inner cylindrical surface of the air pipe; and the two ends of the cooling pipe penetrate the air cover through a cooling inlet pipe and a cooling outlet pipe respe