A theoretical simulation model for optimization of fins on the shell of a hermetic reciprocating compressor

The cost of a hermetic reciprocating compressor is quite dependent on the electric motor employed to drive it. Usually, the higher the motor efficiency, the higher the costs. Therefore, some compressors are designed to operate with low-efficiency electric motors. The main difficulty in such a case is to ensure that the motor operates at a temperature below the upper threshold. This paper presents a simulation model for optimization of fins on the shell of a hermetic reciprocating compressor which operates with a low-efficiency motor. The objective of the simulation is to obtain a set of fins with minimum volume that allows the compressor to operate under a critical operating condition without overheating the electric motor. The simulation model is implemented by coupling a lumped-parameter thermal simulation model of the reciprocating compressor with an optimization algorithm. The results of the thermal simulation are validated with experimental data. Different fin profiles are considered in the analysis. It is concluded that the optimum heat sink solution is conditioned to the minimum fin thickness or to the minimum fin diameter allowed, which are dependent on other compressor design constraints. (paper)