Thermodynamic analysis and optimization of the combined supercritical carbon dioxide Brayton cycle and organic Rankine cycle‐based nuclear hydrogen production system

2021 ◽  
Author(s):  
Qi Wang ◽  
Chunyu Liu ◽  
Run Luo ◽  
Dantong Li ◽  
Rafael Macián‐Juan
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Production ◽  
Supercritical Carbon Dioxide ◽  
Thermodynamic Analysis ◽  
Production System ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Brayton Cycle ◽  
Supercritical Carbon

Hybrid System of Supercritical Carbon Dioxide Brayton Cycle and Carbon Dioxide Rankine Cycle Combined Fuel Cell

2014 ◽  
Author(s):  
Seong Jun Bae ◽  
Yoonhan Ahn ◽  
Jekyoung Lee ◽  
Jeong Ik Lee
Keyword(s):  
Carbon Dioxide ◽  
Fuel Cell ◽  
Supercritical Carbon Dioxide ◽  
Hybrid System ◽  
Thermal Efficiency ◽  
Rankine Cycle ◽  
High Mass ◽  
Brayton Cycle ◽  
Heat Sources ◽  
Supercritical Carbon

The Supercritical Carbon Dioxide (S-CO2) Brayton cycle has been receiving a lot of attention because it can achieve compact configuration and high thermal efficiency at relatively low temperature (450∼750 °C). However, to achieve high thermal efficiency of S-CO2 Brayton cycle, it requires a highly effective recuperator. Moreover, the temperature difference in the heat receiving section is limited for the S-CO2 Brayton cycle to achieve high thermal efficiency results in high mass flow rate and potentially high pressure drop in the cycle. Thus, to resolve these problems while providing flexibility to match with various heat sources, authors suggest a hybrid system of S-CO2 Brayton and Rankine cycle. This hybrid system utilizes the waste heat of the S-CO2 Brayton cycle as the heat input to the Carbon Dioxide (CO2) Rankine cycle. Thus, the recuperator effectiveness does not always have to be high to achieve high efficiency, which results in reduction of the recuperator volume reduction. By controlling amount of the heat transfer from the cooler of the S-CO2 Brayton cycle to the Rankine cycle, the total system can be compact and can achieve wider operating range. Thus, the hybrid system of S-CO2 Brayton cycle and CO2 Rankine cycle can be coupled to various heat sources with more flexibility without trading off the performance. In this paper, Molten Carbonate Fuel Cell (MCFC) system is selected to demonstrate the feasibility of the proposed hybrid cycle system while comparing the proposed system’s performance to that of other cycle layouts as well.

Computational Fluid Dynamics of Supercritical Carbon Dioxide Turbine for Brayton Thermodynamic Cycle

2008 ◽  
Author(s):  
Wi S. Jeong ◽  
Tae W. Kim ◽  
Kune Y. Suh
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Liquid Metal ◽  
Gas Turbine ◽  
High Efficiency ◽  
Thermodynamic Cycle ◽  
Rankine Cycle ◽  
Energy Conversion Efficiency ◽  
Brayton Cycle ◽  
Supercritical Carbon

The supercritical gas turbine Brayton cycle has been adopted in the secondary loop of the Generation IV Nuclear Energy Systems, and also planned to be installed in power conversion cycles of the nuclear fusion reactors. Supercritical carbon dioxide (SCO2) is one of widely considered fluids for this application. The potential beneficiaries include the Secure Transportable Autonomous Reactor - Liquid Metal (STAR-LM), the Korea Advanced Liquid Metal Reactor (KALIMER), and the Battery Omnibus Reactor Integral System (BORIS) which is being developed at the Seoul National University. The reason for these welcomed applications is that the SCO2 Brayton cycle can possibly achieve higher energy conversion efficiency than the steam turbine Rankine cycle. Gas turbine design is crucial part in achieving this high efficiency. In this paper, a one-dimensional gas turbine analysis methodology is applied for optimal design of the component. Case study result shows that the entire turbine efficiency is increased as hub radius is increased for a same number of stage conditions. Comparing the efficiency which is applied the boundary condition, 4 stage turbines have optimal efficiency.

Numerical Simulation of the Performance of an Axial Compressor Operating With Supercritical Carbon Dioxide

2018 ◽  
Author(s):  
Jinlan Gou ◽  
Wei Wang ◽  
Can Ma ◽  
Yong Li ◽  
Yuansheng Lin ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Numerical Simulation ◽  
Supercritical Carbon Dioxide ◽  
Critical Point ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Axial Compressor ◽  
Brayton Cycle ◽  
Supercritical Carbon

Using supercritical carbon dioxide (SCO2) as the working fluid of a closed Brayton cycle gas turbine is widely recognized nowadays, because of its compact layout and high efficiency for modest turbine inlet temperature. It is an attractive option for geothermal, nuclear and solar energy conversion. Compressor is one of the key components for the supercritical carbon dioxide Brayton cycle. With established or developing small power supercritical carbon dioxide test loop, centrifugal compressor with small mass flow rate is mainly investigated and manufactured in the literature; however, nuclear energy conversion contains more power, and axial compressor is preferred to provide SCO2 compression with larger mass flow rate which is less studied in the literature. The performance of the axial supercritical carbon dioxide compressor is investigated in the current work. An axial supercritical carbon dioxide compressor with mass flow rate of 1000kg/s is designed. The thermodynamic region of the carbon dioxide is slightly above the vapor-liquid critical point with inlet total temperature 310K and total pressure 9MPa. Numerical simulation is then conducted to assess this axial compressor with look-up table adopted to handle the nonlinear variation property of supercritical carbon dioxide near the critical point. The results show that the performance of the design point of the designed axial compressor matches the primary target. Small corner separation occurs near the hub, and the flow motion of the tip leakage fluid is similar with the well-studied air compressor. Violent property variation near the critical point creates troubles for convergence near the stall condition, and the stall mechanism predictions are more difficult for the axial supercritical carbon dioxide compressor.

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