Abstract: MAFI-TRENCH frame expander 2.0 is turbine expander which is applicable to the working conditions of medium and high pressure, large flow, and low initial temperature. Compared with piston expander, turbine expander has many advantages, such as small size, light weight, simple structure, less vulnerable parts, small manufacturing and maintenance workload, long continuous working cycle, good regulation performance, high efficiency, convenient operation and maintenance, etc.. So it's widely used in practical engineering. As the core equipment of natural gas deep processing equipment, the key parameters of the expander should be adjusted in time to ensure that the expander always operates in the optimal efficiency range. According to different process conditions in the operation process of the expander, corresponding operation modes are adopted, and the related process optimization measures are put forward in combination with the actual situation to ensure the efficient and smooth operation of the cryogenic refrigeration unit.

Key words: expander, operational efficiency, process optimization