Multi-objective optimisation of ionic liquid parameters for hydrogen compressors by Taguchi and grey relational analysis methods

The ionic liquid compressor developed in recent decades possesses a prospective application for hydrogen storage. The design of this new compressor considering multiple design parameters and objectives is critical for product development. This study investigated the percentage contribution of four design parameters of the ionic liquid to compressor performance by Taguchi and ANOVA. A two-objective optimisation was conducted to identify the near-optimal setting of ionic liquid parameters combining the Taguchi and grey relational analysis (GRA) methods considering both the liquid mass taken off and the specific energy consumption. It was found that the liquid height was the most influential parameter with percentage contributions of 84.65 % and 90.08 % to the liquid mass taken off and specific energy consumption, respectively. The optimal setting is obtained as the liquid height of 15 mm, liquid density of 1600 kg/m³, liquid viscosity of 50 mPa∙s and surface tension of 0.052 N/m.