Abstract: Combining with the trend of large-scale development of domestic cryogenic tank projects, this paper points out the development direction of the gradual upsizing of BOG compressor which is the key equipment for BOG processing. Starting with analyzing the using conditions, the paper analyzes the necessity of low temperature reciprocating structure as the first choice for BOG compressor. It also compares and analyzes the horizontal balance type and vertical labyrinth type reciprocating compressor from many aspects and makes further discussion on type selection and optimization. Finally, combining with the start-up process and flow regulation scheme of BOG compressor, type selection of the compressor is further optimized from the perspective of process operation, which provides strong support for the smooth start-up and stable and reliable operation of the compressor unit.

Key words: BOG compressor, low temperature, reciprocating, type selection, optimization