Mixed refrigerant hydrogen liquefaction device and method of using same

A mixed refrigerant hydrogen liquefaction device, wherein the device comprises a refrigerant compression unit (I), a precooling cold box (II) and a cryogenic cold box (III) which are connected with each other through pipelines, wherein the refrigerant compression unit (I) is provided with a dehydration molecular sieve adsorber (S1), a hydrogen compressor unit (C1), a nitrogen compressor unit (C2) and a mixed refrigerant refrigeration unit (C3), the precooling cold box (II) is provided with a primary precooling heat exchanger (HX1), a secondary precooling heat exchanger (HX2) and a low-temperature molecular sieve adsorber (S2), and the cryogenic cold box (III) is provided with a cryogenic heat exchanger (HX3), an ejector (E1), a supercooling heat exchanger (HX4), a gas-liquid separator (D2), a primary hydrogen expander (X1), and a secondary hydrogen expander (X2);

• wherein the dehydration molecular sieve adsorber (S1) in the refrigerant compression unit (I) is connected with a raw material hydrogen channel of the primary precooling heat exchanger (HX1) and the secondary precooling heat exchanger (HX2) and the low-temperature molecular sieve adsorber (S2) in the precooling cold box (II) through a second pipeline (2), a third pipeline (3) and a fourth pipeline (4), and then is connected with a raw hydrogen channel of the cryogenic heat exchanger (HX3), the ejector (E1), and a raw hydrogen channel of the supercooling heat exchanger (HX4) in the cryogenic cold box (III) in sequence through a fifth pipeline (5), a sixth pipeline (6) and a seventh pipeline (7) to form a circulation channel in the whole process from | raw hydrogen to liquid hydrogen;
• and wherein the outlet of the hydrogen compressor unit (C1) in the refrigerant compression unit (1) is connected with the supercharging ends of the primary hydrogen expander (X1) and the secondary hydrogen expander (X2) and high-pressure circulating hydrogen channels of the primary precooling heat exchanger (HX1) and the secondary precooling heat exchanger (HX2) in the precooling cold box (II) in sequence through an eleventh pipeline (11), a twelfth pipeline (12) and a thirteenth pipeline (13), and then is connected with a high-pressure circulating hydrogen channel of the cryogenic heat exchanger (HX9) in the cryogenic cold box (III) through a fourteenth pipeline (14), and is connected with the primary hydrogen expander (X1), the secondary hydrogen expander (X2) and a throttle valve (V1) through a fifteenth pipeline (15), a seventeenth pipeline (17) and a nineteenth pipeline (19) among three branch pipelines, respectively, the throttle valve (V1) is connected with low-temperature circulating hydrogen channels of the gas-liquid separator (D2) and the supercooling heat exchanger (HX4) in sequence through a twentieth pipeline (20), a twenty-first pipeline (21) and a twenty-second pipeline (22), the gas-liquid separator (D2) is connected with a first low-pressure circulating hydrogen channel of the cryogenic heat exchanger (HX3), first low-pressure circulating hydrogen channels of the secondary precooling heat exchanger (HX2) and the primary precooling heat exchanger (HX1), and a low-pressure section of the hydrogen compressor unit (C1) in sequence through a twenty-third pipeline (23), a twenty-fourth pipeline (24), a twenty-fifth pipeline (25) and a twenty-sixth pipeline (26), the primary hydrogen expander (X1) and the secondary hydrogen expander (X2) are connected with a second low-pressure circulating hydrogen channel of the cryogenic heat exchanger (HX3) through a sixteenth pipeline (16) and an eighteenth pipeline (18), respectively, and then connected with second low-pressure circulating hydrogen channels of the secondary precooling heat exchanger (HX2) and the primary precooling heat exchanger (HX1), and a high-pressure section of the hydrogen compressor unit (C1) through a twenty-seventh pipeline (27), a twenty-eighth pipeline (28), and a twenty-ninth pipeline (29), so as to form a hydrogen refrigeration circulation channel.