Carbon dioxide liquefaction device and process

The invention discloses a carbon dioxide liquefaction device and a process. The carbon dioxide liquefaction device includes a carbon dioxide all-in-one liquefaction device, the carbon dioxide all-in-one liquefaction device comprises a liquid collecting tube box, a one-section cooler, a tube intermediate tube box and a two-section cooler in sequence from bottom to top; the one-section cooler and the two-section cooler are each of a tubular heat exchanger structure, the tubes in the one-section cooler and the two-section cooler communicate with each other through the tube intermediate tube box,and the tube of the one-section cooler communicates with the liquid collecting tube box; and the shells of the one-section cooler and the two-section cooler communicate with each other through a U-shaped tube, a carbon dioxide gas inlet is formed in tube intermediate tube box and connected with a three-section outlet of a carbon dioxide compressor through a carbon dioxide gas inlet tube line, a shell inlet is formed in th