Volumetric efficiency and pressure pulsations of a triplex reciprocating supercritical CO2 pump

• Published in: The Journal of supercritical fluids Vol. 168; p. 105072
• Main Authors: Aakre, Shaun R., Anderson, Mark H., Brooks, Paul W.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-02-2021
• Subjects: CO2 power cycle; CO2 utilization; Compact heat exchanger; Natural oil extraction; Reciprocating compressor; Reciprocating compressor; Compact heat exchanger; CO2 power cycle; Natural oil extraction; CO2 utilization
• ISSN: 0896-8446; 1872-8162
• DOI: 10.1016/j.supflu.2020.105072

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•Measured the volumetric efficiency with inlet pressures between 60 and 160 bar.•Calculated mechanical efficiency with sub- and super-critical inlet conditions.•Measured pressure pulsations in the discharge piping over the full speed range.•Examined use of the buffer tank near the discharge port as a pulsation dampener.•Incorporated the pump into a loop for testing of compact heat exchangers.
A reciprocating triplex pump has been integrated into a closed-loop supercritical carbon dioxide test facility. The pump is designed to compress liquid or supercritical carbon dioxide and has a maximum volumetric flow rate of 51 L/min. A sweep across the pump’s speed range of 100–1000 rev/min was performed with inlet conditions between 60 and 160 bar. The volumetric efficiency was found to increase as pump speed increased from 10 to 40 % before it plateaued at higher pump speeds. The mechanical efficiency increased linearly with pump speed and was not affected by system pressure. Pressure pulsations caused by the plungers and valves were also measured at each speed. A 35-liter buffer volume, connected near the pump’s discharge was isolated at each speed to determine its effectiveness as a pulsation dampener. Overall the reciprocating pump was shown to perform exceptionally with liquid or supercritical inlet conditions applicable to many supercritical fluid applications.