Solutions of supercritical CO2 flow through a convergent-divergent nozzle with real gas effects

2018 ◽  
Vol 116 ◽  
pp. 127-135 ◽  
Author(s):  
S.K. Raman ◽  
H.D. Kim
Keyword(s):  
Supercritical Co2 ◽  
Real Gas ◽  
Real Gas Effects ◽  
Flow Through ◽  
Co2 Flow

Investigations on Transonic Flow of Super-Critical CO2 Through Carbon Ring Seals

2015 ◽  
Author(s):  
Eike Hylla ◽  
Markus Schildhauer ◽  
Richard Büssow ◽  
Kolja Metz ◽  
Robert Klawes
Keyword(s):  
Test Procedure ◽  
Measured Data ◽  
Temperature Deformation ◽  
Experimental Investigations ◽  
Real Gas ◽  
Real Gas Effect ◽  
Flow Through ◽  
Co2 Flow ◽  
Gas Effect ◽  
Good Agreement

This paper gives an overview of numerical and experimental investigations on super-critical CO2 flow through carbon floating ring seals (CRS). The established simulation model considers the real gas effect, temperature deformation and the shaft rotation. For validation extensive measurements of the leakage rates, pressures and temperatures at various positions within the seal were conducted on a compressor prototype. Details of the measurement setup and the test procedure are given. The experimental results are discussed. A comparison of the measured data to the model prediction shows an overall good agreement.

Calculations of Real-Gas Effects in Flow Through Critical-Flow Nozzles

1964 ◽  
Vol 86 (3) ◽  
pp. 519-525 ◽  
Author(s):  
Robert C. Johnson
Keyword(s):  
Mass Flow ◽  
Room Temperature ◽  
The Other ◽  
Critical Flow ◽  
Real Gas ◽  
One Dimensional ◽  
Real Gas Effects ◽  
Computer Calculations ◽  
Flow Through

Computer calculations have been made of how real-gas effects modify the conventional one-dimensional equations for mass flow of air, nitrogen, oxygen, hydrogen, argon, helium, and steam through a nozzle. The results indicate that for critical flow of air, at room temperature and 100 atmospheres pressure, real-gas effects of 3 1/2 percent exist. Similar magnitudes are found for the other gases.

scholarly journals An Investigation of Real Gas Effects in Supercritical CO2 Centrifugal Compressors

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Nikola D. Baltadjiev ◽  
Claudio Lettieri ◽  
Zoltán S. Spakovszky
Keyword(s):  
Critical Point ◽  
Supercritical Co2 ◽  
Pressure Curve ◽  
Compressor Stage ◽  
Local Flow ◽  
Real Gas ◽  
Flow Acceleration ◽  
Vapor Pressure Curve ◽  
Thermodynamic Conditions ◽  
Real Gas Effects

This paper presents a comprehensive assessment of real gas effects on the performance and matching of centrifugal compressors operating in supercritical CO2. The analytical framework combines first principles based modeling with targeted numerical simulations to characterize the internal flow behavior of supercritical fluids with implications for radial turbomachinery design and analysis. Trends in gas dynamic behavior, not observed for ideal fluids, are investigated using influence coefficients for compressible channel flow derived for real gas. The variation in the properties of CO2 and the expansion through the vapor-pressure curve due to local flow acceleration are identified as possible mechanisms for performance and operability issues observed near the critical point. The performance of a centrifugal compressor stage is assessed at different thermodynamic conditions relative to the critical point using computational fluid dynamics (CFD) calculations. The results indicate a reduction of 9% in the choke margin of the stage compared to its performance at ideal gas conditions due to variations in real gas properties. Compressor stage matching is also impacted by real gas effects as the excursion in corrected mass flow per unit area from inlet to outlet increases by 5%. Investigation of the flow field near the impeller leading edge at high flow coefficients shows that local flow acceleration causes the thermodynamic conditions to reach the vapor-pressure curve. The significance of two-phase flow effects is determined through a nondimensional parameter that relates the time required for liquid droplet formation to the residence time of the flow under saturation conditions. Applying this criterion to the candidate compressor stage shows that condensation is not a concern at the investigated operating conditions. In the immediate vicinity of the critical point however, this effect is expected to become more prominent. While the focus of this analysis is on supercritical CO2 compressors for carbon capture and sequestration (CCS), the methodology is directly applicable to other nonconventional fluids and applications.

An Investigation of Real Gas Effects in Supercritical CO2 Centrifugal Compressors

2014 ◽  
Author(s):  
N. Baltadjiev ◽  
C. Lettieri ◽  
Z. Spakovszky
Keyword(s):  
Critical Point ◽  
Supercritical Co2 ◽  
Pressure Curve ◽  
Compressor Stage ◽  
Local Flow ◽  
Real Gas ◽  
Flow Acceleration ◽  
Vapor Pressure Curve ◽  
Thermodynamic Conditions ◽  
Real Gas Effects

This paper presents a comprehensive assessment of real gas effects on the performance and matching of centrifugal compressors operating in supercritical CO2. The analytical framework combines first principles based modeling with targeted numerical simulations to characterize the internal flow behavior of supercritical fluids with implications for radial turbomachinery design and analysis. Trends in gas dynamic behavior, not observed for ideal fluids, are investigated using influence coefficients for compressible channel flow derived for real gas. The variation in the properties of CO2 and the expansion through the vapor-pressure curve due to local flow acceleration are identified as possible mechanisms for performance and operability issues observed near the critical point. The performance of a centrifugal compressor stage is assessed at different thermodynamic conditions relative to the critical point using CFD calculations. The results indicate a reduction of 9% in the choke margin of the stage compared to its performance at ideal gas conditions due to variations in real gas properties. Compressor stage matching is also impacted by real gas effects as the excursion in corrected mass flow per unit area from inlet to outlet increases by 5%. Investigation of the flow field near the impeller leading edge at high flow coefficients shows that local flow acceleration causes the thermodynamic conditions to reach the vapor-pressure curve. The significance of two-phase flow effects is determined through a non-dimensional parameter that relates the time required for liquid droplet formation to the residence time of the flow under saturation conditions. Applying this criterion to the candidate compressor stage shows that condensation is not a concern at the investigated operating conditions. In the immediate vicinity of the critical point however, this effect is expected to become more prominent. While the focus of this analysis is on supercritical CO2 compressors for carbon capture and sequestration, the methodology is directly applicable to other non-conventional fluids and applications.

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