Design Methodology of Supercritical CO2 Brayton Cycle Turbomachineries

Lee, Jekyoung; Lee, Jeong Ik; Ahn, Yoonhan; Yoon, Ho-Joon

doi:10.1115/gt2012-68933

Cited by 37 publications

(17 citation statements)

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“…Zhang et al [17] achieved the non-design effect of S-CO 2 radial turbine by changing the diameter of the leading edge of the nozzle, and carried out comprehensive numerical analysis to obtain the non-design performance of the radial turbine. J. Lee et al [18] proposed an improved method for mechanical design of S-CO 2 turbines using programming methods, and compared the thermal performance of axial turbines and radial turbines under the same conditions. Hiroshi Hasuike et al [19] designed an S-CO 2 gas turbine with a net output power of 10 kW and a working fluid recirculation flow rate of 1.2 kg/s, and conducted a principle and demonstration test.…”

Section: Introductionmentioning

confidence: 99%

Aerodynamic Design and Off-design Performance Analysis of a Multi-Stage S-CO2 Axial Turbine Based on Solar Power Generation System

et al. 2019

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Solar energy is an inexhaustible source of clean energy. Meanwhile, supercritical carbon dioxide has excellent characteristics such as easy access to critical conditions, high density, and low viscosity, making it one of the most popular circulating working fluids in solar power generation technology. However, solar power generation systems are severely affected by geographical distribution, seasonal variations and day-night cycles. Therefore, efficient and adaptable turbine design is the key to realize supercritical carbon dioxide solar power generation technology. In this paper, the initial thermodynamic design of 10 MW S-CO2 three-stage axial turbine is completed by self-developed thermodynamic design software, and the key thermodynamic and structural parameters are obtained. The optimal design of turbine and its aerodynamic performance at rated operating conditions are obtained by using a three-dimensional aerodynamic numerical analysis and optimization method. At last, nine off-design conditions are analyzed in detail. The results show that the designed turbine output power is 10.37 MW and the total-total efficiency is 91.60%. It can operate efficiently and steadily in the range of output power from 16.2% to 155.9%. It can adapt to the variable operating conditions of solar power generation system and meet the design requirements.

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Section: Introductionmentioning

confidence: 99%

Aerodynamic Design and Off-design Performance Analysis of a Multi-Stage S-CO2 Axial Turbine Based on Solar Power Generation System

et al. 2019

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“…But neither of them did a 3D calculation for their design results. There are also many other universities and research institutes that have carried out relevant research on the design strategy of SCO 2 compressors [7][8][9][10][11][12] and some research institutes have carried out experiments [13][14][15]. More recently, Rinaldi (2014) and colleagues utilized an in-house fluid dynamic solver and simulated the test compressor of Sandia National Laboratories (SNL) based on the steady state method [16].…”

Section: Introductionmentioning

confidence: 99%

Preliminary Design and Model Assessment of a Supercritical CO2 Compressor

et al. 2018

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Abstract:The compressor is a key component in the supercritical carbon dioxide (SCO 2 ) Brayton cycle. In this paper, the authors designed a series of supercritical CO 2 compressors with different parameters. These compressors are designed for 100 MWe, 10 MWe and 1 MWe scale power systems, respectively. For the 100 MWe SCO 2 Brayton cycle, an axial compressor has been designed by the Smith chart to test whether an axial compressor is suitable for the SCO 2 Brayton cycle. Using a specific speed and a specific diameter, the remaining two compressors were designed as centrifugal compressors with different pressure ratios to examine whether models used for air in the past are applicable to SCO 2 . All compressors were generated and analyzed with internal MATLAB programs coupled with the NIST REFPROP database. Finally, the design results are all checked by numerical simulations due to the lack of reliable experimental data. Research has found that in order to meet the de Haller stall criterion, axial compressors require a considerable number of stages, which introduces many additional problems. Thus, a centrifugal compressor is more suitable for the SCO 2 Brayton cycle, even for a 100 MWe scale system. For the performance prediction model of a centrifugal compressor, the stall predictions are compared with steady numerical calculation, which indicates that past stall criteria may also be suitable for SCO 2 compressors, but more validations are needed. However, the accuracy of original loss models is found to be inadequate, particularly for lower flow and higher pressure ratio cases. Deviations may be attributed to the underestimation of clearance loss according to the result of steady simulation. A modified model is adopted which can improve the precision to a certain extent, but more general and reasonable loss models are needed to improve design accuracy in the future.

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“…Jekyoung Lee [95] has attempted to combine and integrate the methods of axial and radial turbomachinery design together into one code, and to account for the non ideal nature of the supercritical CO 2 around the critical point. Ventura et al [15] create an automatic preliminary radial inflow turbine design code (TOPGEN) based on these well-developed correlations.…”

Section: Preliminary Design For Sco 2 Radial Inflow Turbinesmentioning

confidence: 99%

Development and application of simulation tools for supercritical carbon dioxide radial inflow turbine

Qi¹

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Supercritical CO 2 (sCO 2) cycles are considered a promising technology for next generation concentrated solar thermal, waste heat recovery and nuclear applications. Particularly at small to medium scale, where radial inflow turbines can be employed, using sCO 2 results in both system advantages and simplifications of the turbine design, leading to improved performance and cost reductions. Using CO 2 as operating fluid for a radial inflow turbine creates new design, new operating and new modelling challenges. These include mean-line design with enhancing loss models suitable for large dense gas, non-ideal gas behaviour within the blade channel and blade geometry optimisations. Since the supercritical CO 2 has a larger density than the steam or air at the same condition, it might not be adequate to use the well developed loss model to conduct the mean-line design of the whole stage. Since the flow phenomena within the blade channels are complex, involving fluid flow, shock wave position, boundary layer separation, use of the ideal gas model to predict the performance of the turbine might not be adequate. To address these issues, the enhanced one-dimensional loss models, a non-ideal compressible fluid dynamics Riemann solver, and a stator geometry optimiser are developed to create insight on the flow dynamics of supercritical CO 2 radial inflow turbines. The mean-line design results, nonideal compressible fluid dynamics Riemann solver development and stator geometry optimisation are described in details next. The first part aims to provide new insight towards the design of radial turbines for operation with sCO 2 in the 100 kW to 200 kW range. The quasi one-dimensional (1D) mean-line design code TOP-GEN is enhanced to explore and map the radial turbine design space. This mapping process over a state space defined by Head and Flow coefficients allows the selection of an optimum turbine design, while balancing performance and geometrical constraints. By considering three operating points with varying power levels and rotor speeds the effect of these on feasible design space and performance is explored. This provides new insight towards the key geometric features and operational constraints that limit the design space as well as scaling effects. Finally review of the loss breakdown of the designs elucidates the importance of the respective loss mechanisms. Similarly it allows the identification of a design directions that lead to improved performance. Overall this work shows that turbine design with efficiencies in the range 78 % to 82 % are possible in this power range and provides insight into the design space that allows the selection of optimum designs. Next, a new solver for OpenFOAM for non-ideal compressible fluid dynamics is developed. The new solver uses a real-gas Riemann solver, which is based on look-up tables to capture real gas properties. This is achieved by the addition of a new thermodynamic library tightly coupled with the OpenFOAM library. For the solver, the HLLC ALE flux calculator has been modifi...

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Design Methodology of Supercritical CO2 Brayton Cycle Turbomachineries

Cited by 37 publications

References 0 publications

Aerodynamic Design and Off-design Performance Analysis of a Multi-Stage S-CO2 Axial Turbine Based on Solar Power Generation System

Aerodynamic Design and Off-design Performance Analysis of a Multi-Stage S-CO2 Axial Turbine Based on Solar Power Generation System

Preliminary Design and Model Assessment of a Supercritical CO2 Compressor

Development and application of simulation tools for supercritical carbon dioxide radial inflow turbine

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