Plate and shell heat exchangers and detachable plate heat exchangers are used in the modularization of 50,000 cubic meters of LNG skid-mounted devices, replacing the previous tube and tube heat exchangers. Plate and shell heat exchangers are high-pressure in the domestic LNG industry. The application of process section is the first case. A total of 3 plate and shell heat exchangers and 3 detachable plate heat exchangers were used. Plate and shell heat exchangers are used for regeneration gas heating, regeneration gas cooling and absorption tower top cooling, and detachable heat exchangers are used for lean and rich liquid heat exchange, lean liquid cooling and carbon dioxide cooling. Compared with the tube heat exchanger, this scheme has increased the investment cost of the plate heat exchanger, but because the plate heat exchanger has high heat transfer efficiency, small footprint, reliable performance, reduced operating costs and energy saving. We use detachable plate heat exchangers in the low-pressure process section of LNG purification, instead of traditional tubular heat exchangers.