Research on the performance of liquid ring compressors under high compression ratios

Abstract

This paper investigates the performance degradation of liquid ring compressors under high compression ratio conditions. The study focuses on the single-stage, single-acting 2BE1-153 liquid ring compressor, with the double-acting second stage of the 2BE1-S202 liquid ring compressor serving as a control to validate the universality of the findings. A gas–liquid two-phase flow model was established through numerical simulation to reflect the operational process. Combining experimental testing with numerical simulation, this study analyzes the mechanisms of performance deterioration in liquid ring compressors under high compression ratios. Research findings indicate that as the compression ratio increases from 2 to 3: the thinning of the liquid ring exacerbates gas leakage, causing a significant reduction in intake volume from 0.178 m³·s⁻¹ to 0.067 m³ s⁻¹. When the compression ratio exceeds the critical value, further increases in compression ratio result in reduced isothermal compression work due to diminished intake volume. Concurrently, increased hydraulic losses lead to higher shaft power consumption. This ultimately causes a further decline in isothermal efficiency from 45.2% to 23.7%. Insufficient compression energy at high compression ratios triggers gas recirculation. Increasing the impeller peripheral speed is crucial for enhancing the critical compression ratio and boosting compression capacity. Furthermore, the discharge port structure (including its initial angle and area) significantly impacts performance. Analysis of the pressure gradient in the discharge port area at different compression ratios indicates that optimizing the discharge port configuration can reduce energy losses and improve efficiency.