Numerical Analysis of Real Fluid Behavior Effects on a Sliding-Vane Compressor Comprehensive Model

This work presents a simulation model on a sliding vane compressor based on a lumped parameter model. The model is capable of predicting the performance of sliding-vane compressors. The model is divided into different sub-sections to evaluate the compressor's geometry, kinetics, thermodynamics, and rotor dynamics. The output of the tool includes the compressor unit's performance, such as volumetric flow rate, mechanical power, and process efficiency. The study examines the tool's ability to perform quick and efficient analyses using using either ideal or real fluid characterization, based on the REFPROP code. The code is validated against one experimental point. Simulations were conducted on a mid-size sliding-vane rotary compressor operating with three different types of working fluids from 20 °C and 1 bar (absolute) to 11 bar at 1500 rpm. In the ideal fluid case, simulations took 10–27 s, while real fluid assumptions took 1038–4329 s. The volumetric flow rate was influenced by the gas used, but changes among fluid models were not substantial, with a mean absolute percent difference of 0.5%. Mechanical power consumption was affected by the fluid choice and gas model, leading to a mechanical power difference between 0.4 and 1.1% in the ideal gas case. The specific mechanical work showed greater deviations among the fluids, with methane molar mass coherently increasing its value. Results show that the model developed is able to assess the major phenomena of sliding-vane compressors, and the ideal fluid model should be preferred when possible since computational times are significantly reduced with comparable results.