Influence of Supercritical Carbon Dioxide Condensation on Flow and Performance

2020 ◽  
pp. 1-7
Author(s):  
Violetta Bushanova ◽  
Zheng Ping Zou ◽  
Maxim Ovchinnikov
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
And Performance ◽  
Supercritical Carbon

Effect of Turbulence and Flow Distortion on the Performance of Conical Diffusers Operating on Supercritical Carbon Dioxide

2013 ◽  
Author(s):  
A. López ◽  
B. Monje ◽  
D. Sánchez ◽  
R. Chacartegui ◽  
T. Sánchez
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Static Pressure ◽  
Pressure Rise ◽  
Working Fluid ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Conical Diffuser ◽  
And Performance ◽  
Supercritical Carbon

A rapidly growing interest in the supercritical carbon dioxide power cycle has been observed in the last years due to the superb performance of this system in concentrated solar and nuclear applications; a sample of this interest is the number of technical publications submitted to Turbo Expo in the last couple of years. As active members of the supercritical carbon dioxide (SCO2) community, the authors of this work have lately studied the fundamentals of SCO2 flows. The approach followed has nevertheless been different to that of most researchers since it has concentrated on simple devices rather than on an entire turbomachinery. Thus, recent contributions by the authors have shown that major differences are to be expected when air and SCO2 diffuse through simple conical divergent ducts at subsonic speeds, most of which derive from the very different characteristics and performance of the boundary layer when adverse pressure gradients are faced. In particular, the effects of geometry (i.e. divergence angle) and aerodynamic blockage on the static pressure rise coefficient of such a conical diffuser have been reported by the authors in recent technical works. This work presents the effects of other aerodynamic features of the inlet flow to a conical diffuser on the capacity to convert kinetic energy into static pressure. Two flow features are studied: (i) the distortion of the inlet velocity distribution and (ii) the turbulence intensity of the inlet flow. A parallel analysis is developed for air and SCO2 showing that the effects of both distortion and turbulence on diffuser performance are sensitive to the working fluid of choice.

Selecting the Optimum Supercritical CO2 Cycle for Indirect-Fired Applications

2019 ◽  
Author(s):  
Brittany Tom ◽  
January Smith ◽  
Aaron M. McClung
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Supercritical Co2 ◽  
Operating Conditions ◽  
Working Fluid ◽  
Performance Goals ◽  
Brayton Cycle ◽  
Power Cycle ◽  
And Performance ◽  
Supercritical Carbon

Abstract Existing research has demonstrated the viability of supercritical carbon dioxide as an efficient working fluid with numerous advantages over steam in power cycle applications. Selecting the appropriate power cycle configuration for a given application depends on expected operating conditions and performance goals. This paper presents a comparison for three indirect fired sCO2 cycles: recompression closed Brayton cycle, dual loop cascaded cycle, and partial condensation cycle. Each cycle was modeled in NPSS with an air side heater, given the same baseline assumptions and optimized over a range of conditions. Additionally, limitations on the heater system are discussed.

scholarly journals Preparation and Performance of Supercritical Carbon Dioxide Thickener

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 78
Author(s):  
Bin Liu ◽  
Yanling Wang ◽  
Lei Liang
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Molecular Design ◽  
Simulation Method ◽  
Capillary Viscometer ◽  
Low Viscosity ◽  
New Ideas ◽  
And Performance ◽  
Core Displacement ◽  
Supercritical Carbon

The low sand-carrying problem caused by the low viscosity of supercritical carbon dioxide (SC–CO2) limits the development of supercritical CO2 fracturing technology. In this study, a molecular simulation method was used to design a fluorine-free solvent-free SC–CO2 thickener 1,3,5,7-tetramethylcyclotetrasiloxane (HBD). Simulations and experiments mutually confirm that HBD-1 and HBD-2 have excellent solubility in SC–CO2. The apparent viscosity of SC–CO2 after thickening was evaluated with a self-designed and assembled capillary viscometer. The results show that when the concentration of HBD-2 is 5 wt.% (305.15 K, 10 MPa), the viscosity of SC–CO2 increases to 4.48 mPa·s. Combined with the capillary viscometer and core displacement device, the low damage of SC–CO2 fracturing fluid to the formation was studied. This work solves the pollution problems of fluoropolymers and co-solvents to organisms and the environment and provides new ideas for the molecular design and research of SC–CO2 thickeners.

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