METHOD FOR THE LIQUEFACTION OF A HYDROCARBON-RICH FLOW

摘要

Disclosed is a method for liquefying a hydrocarbon-rich flow, particularly a natural gas flow, by indirectly exchanging heat with a nitrogen refrigeration cycle. The nitrogen circulating in the nitrogen refrigeration cycle is compressed in several stages, is cooled, and is subdivided into at least two partial flows, and said at least two partial flows are subjected to a refrigerating expansion process at different temperature levels. According to the invention, the partial nitrogen flow (15, 16) expanded (X') at the higher temperature level is fed to the multi-stage compression (V1, V2,...) at an average pressure level, and at least some of the partial nitrogen flow (12, 13) expanded at the colder or coldest temperature level is liquid after being expanded (X, v').