The performance characteristics of single-stage and multistage regenerative flow compressors for natural gas compression application

Abstract

The compact size, high reliability and low maintenance required by regenerative flow compressors (RFCs) have made them very useful for low-pressure (0.2–15 lb/in2 gauge) natural gas compression required by microturbine systems. Very limited test data are available in the literature on gases as working fluids in regenerative turbomachines, resulting in a scarcity of design information. Most of the testing conducted in the past was on single-stage RFCs and no evidence of experimental data on multistage RFCs is available in the literature. This paper presents a large amount of single-stage test data along with an investigation for the first time of performance characteristics of a four-stage RFC. Testing is carried out over a wide range of speeds using natural gas and air as working fluids. Experimental data are presented in terms of various non-dimensional performance parameters. Several correlations are developed between these non-dimensional performance parameters and RFC geometry. Single-stage test data are used to study the effect of blade geometry, channel geometry, channel area ratio and pitch-cord ratio on performance. A few important sources of losses in RFCs are identified. Moreover, through the presented non-dimensional test data and available test data in the literature, a generalized design procedure is proposed, which can be very useful for designers and engineers working in regenerative turbomachinery.