Method and apparatus for controlling a refrigerant compressor, and use thereof in a method of cooling a hydrocarbon stream

摘要

A method of controlling one or more refrigerant compressors (12) for one or more gaseous streams (10) at a normal operating temperature. At least one refrigerant compressor (12) has a vapour recirculation line (30). A compressor feed stream (10a) is provided from a combination of a vapour recirculation stream (30) from the vapour recirculation line (30) and an at least partly evaporated refrigerant stream (8). The compressor feed stream (10a) is passed through a suction drum (11) to provide a compressor gaseous stream (10), which is passed through the refrigerant compressor (s) (12). The inlet temperature T1 of the compressor gaseous stream (10) is determined, and cooling of a refrigerant stream is controlled in response to temperature T1 to provide the compressor gaseous stream (10) at the normal operating temperature of at least one refrigerant compressor (12).