Modelling and study of efficiency of compressor C-661 of Abadan oil refining company

Numerous factors such as duct fouling, corrosion and wear of blades and internal return currents affect the performance quality and efficiency of the centrifugal compressor and can change vital variables such as pressure ratio, mass flow rate and energy consumption of the device that in turn affect the profitability and safety of the operating unit. In this study, the performance of compressor C-661 of Abadan Oil Refining Company, which is of centrifugal type with two operational stages and an intermediate cooling, has been investigated with the aim of evaluating its deviation from the manufacturer’s predicted conditions. Components that indicate the quality of compressor performance such as pressure ratio, mass flow rate, efficiency and power consumption have been measured. The results showed that this compressor after eight years of continuous operation, had a decrease of less than 1% of polytrophic efficiency in the first stage and a decrease of nearly 4% of polytrophic efficiency in the second stage. The average pressure ratio of the device has decreased by about 9% and the average mass flow rate has decreased by about 14% compared to the design point. The main cause of this decrease is the fouling of the device. The mechanical efficiency drop was close to 25%, which could be due to the decrease in steam turbine efficiency. Therefore, by using health coefficients, the performance diagram of this compressor was modified to show the current operating conditions and the overall equipment Effectiveness of the compressor was calculated with a new method. The economic survey also showed an 18% drop in productivity for the device.