Designing a Linear Motor Recip Compressor to Achieve 12,700 psi Outlet Pressure
The Department of Energy (DOE) has a goal of increasing the compression efficiency and reducing the cost of forecourt hydrogen compression. Southwest Research Institute (SwRI) and ACI Services, Inc. (ACI) are developing the Linear Motor Reciprocating Compressor (LMRC) to meet those goals. The proposed advanced compression system utilizes a novel and patented concept of driving a permanent magnet piston assembly inside a hermetically sealed compressor cylinder through electromagnetic windings. The LMRC design minimizes the mechanical part count and has no process gas leakage to atmosphere. The LMRC has no rod, rod packing, crankshaft, coupling, or separate motor/driver. In addition, the LMRC is able to improve the compression efficiency of the hydrogen compression process by eliminating bearing losses and minimizing piston speed, which minimizes aerodynamic losses. High pressures, electromagnetic fields, and a hydrogen environment are the main design obstacles that are being overcome to design a linear motor reciprocating compressor that can achieve a 12,700 psia discharge pressure. Some of the associated technology developments may be applicable to high-pressure natural gas and process compressors in the future.