Theoretical study and optimization of a CNG fueling sub-station compressor driven by linear motor

As an important equipment in compressed natural gas fueling sub-station (CNG sub-station), the CNG sub-station compressor compresses natural gas from CNG tube trailer to cascade reservoirs or CNG vehicle. In this paper, a two stage CNG sub-station compressor driven by linear motor was presented. Based on theoretical analysis of the proposed compressor, a mathematical model was developed to optimize the key parameters, which involved four sub modules: piston motion module, two stage compress module, linear motor module, and CNG tube trailer module. Based on the numerical simulation of a CNG sub-station compression process with the presented compressor, an adaptive mechanism of compression ratio and a utilization mechanism of kinetic energy were proposed. Moreover, an improved particle swarm optimization (PSO) algorithm was introduced to minimize energy consumption and maximize the average capacity of the compressor. The diameters of piston and clump weights of the two stages were optimized by the proposed algorithm. Finally, the performance of conventional solution and optimal solution were compared by simulation.