Design and FEA of tandem cylinder for reciprocating gas compressor

The compressor is an integral part of the mechanical process industry, widely used in the oil and gas sector. The tandem cylinder belongs to the class of small cylinders with a range of bore diameter from 1.8" to 1.25". Methane gas is compressed in a cylinder to transfer the gas from one place to another. In the three-stage reciprocating gas compressor, the tandem cylinder compresses the gas from 160 bar to 225 bar at an operating speed of 1800 rpm. The tandem cylinder is a single-acting cylinder connected to the three-stage compressor by a common connecting rod The present research work uses ASME codes and API 618 standards to design the tandem cylinder. The numerical investigation is carried out using a commercial tool to study the thermal stress concentration, total deformation, and modal analysis. In a tandem cylinder, the thermal stress ranges from 50 to 150 MPa, below the allowable stress, and the deformation all along the surface of the bore is 0.01 mm, below the maximum permissible deformation. The numerical investigation shows a frequency of 97 Hz, which is significantly higher than the natural frequency. Consequently, the tandem cylinder is stable under the specified operating conditions and won’t resonate.