scholarly journals The flow path characteristics analysis for supercritical carbon dioxide gas turbines

2019 ◽  
Vol 124 ◽  
pp. 01006
Author(s):  
A. N. Rogalev ◽  
N. D. Rogalev ◽  
V. O. Kindra ◽  
E. Y. Grigoriev ◽  
B. A. Makhmutov
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Gas Turbines ◽  
Velocity Ratio ◽  
Carbon Dioxide Concentration ◽  
Flow Path ◽  
Working Fluid ◽  
Carbon Dioxide Gas ◽  
Reaction Degree ◽  
Supercritical Carbon

Rising carbon dioxide concentration in the atmosphere is probably the main reason of global warming. The development of the oxy-fuel combustion cycles is a possible way to decrease the energy sector contribution in the emission process. However, an unusual composition and thermodynamic parameters of the working fluid cause the necessity of revision of the main equipment characteristics, especially for the supercritical carbon dioxide gas turbine. This study presents the method and the results of the flow path preliminary analysis for the new generation gas turbines working on carbon dioxide. The flow path shape with a constant root diameter of seven stages was chosen as the most reasonable due to cheap manufacturing. Influence of reaction degree of stages and velocity ratio on stage geometric parameters are revealed. It was found that the optimal reaction degree and velocity ratio are equal to 0.25 and 0.36 correspondingly. Thermal and constructive stages characteristics of the 350 MW turbine are determined.

scholarly journals DESIGN OF A 1 MWTH SUPERCRITICAL CARBON DIOXIDE PRIMARY HEAT EXCHANGER TEST SYSTEM

2020 ◽  
pp. 1-34
Author(s):  
Matthew Carlson ◽  
Francisco Alvarez
Keyword(s):  
Carbon Dioxide ◽  
Heat Exchanger ◽  
Supercritical Carbon Dioxide ◽  
Technology Development ◽  
Ambient Air ◽  
Test System ◽  
Department Of Energy ◽  
Working Fluid ◽  
Levelized Cost Of Electricity ◽  
Supercritical Carbon

Abstract A new generation of Concentrating Solar Power (CSP) technologies is under development to provide dispatchable renewable power generation and reduce the levelized cost of electricity (LCOE) to 6 cents/kWh by leveraging heat transfer fluids (HTF) capable of operation at higher temperatures and coupling with higher efficiency power conversion cycles. The U.S. Department of Energy (DOE) has funded three pathways for Generation 3 CSP (Gen3CSP) technology development to leverage solid, liquid, and gaseous HTFs to transfer heat to a supercritical carbon dioxide (sCO2) Brayton cycle. This paper presents the design and off-design capabilities of a 1 MWth sCO2 test system that can provide sCO2 coolant to the primary heat exchangers (PHX) coupling the high-temperature HTFs to the sCO2 working fluid of the power cycle. This system will demonstrate design, performance, lifetime, and operability at a scale relevant to commercial CSP. A dense-phase high pressure canned motor pump is used to supply up to 5.3 kg/s of sCO2 flow to the primary heat exchanger at pressures up to 250 bar and temperatures up to 715 °C with ambient air as the ultimate heat sink. Key component requirements for this system are presented in this paper.

Modeling Off-Design and Part-Load Performance of Supercritical Carbon Dioxide Power Cycles

2013 ◽  
Author(s):  
John J. Dyreby ◽  
Sanford A. Klein ◽  
Gregory F. Nellis ◽  
Douglas T. Reindl
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Ambient Air ◽  
Working Fluid ◽  
Brayton Cycle ◽  
Heat Rejection ◽  
Power Cycles ◽  
Part Load ◽  
Dry Cooling ◽  
Supercritical Carbon

Continuing efforts to increase the efficiency of utility-scale electricity generation has resulted in considerable interest in Brayton cycles operating with supercritical carbon dioxide (S-CO2). One of the advantages of S-CO2 Brayton cycles, compared to the more traditional steam Rankine cycle, is that equal or greater thermal efficiencies can be realized using significantly smaller turbomachinery. Another advantage is that heat rejection is not limited by the saturation temperature of the working fluid, facilitating dry cooling of the cycle (i.e., the use of ambient air as the sole heat rejection medium). While dry cooling is especially advantageous for power generation in arid climates, the reduction in water consumption at any location is of growing interest due to likely tighter environmental regulations being enacted in the future. Daily and seasonal weather variations coupled with electric load variations means the plant will operate away from its design point the majority of the year. Models capable of predicting the off-design and part-load performance of S-CO2 power cycles are necessary for evaluating cycle configurations and turbomachinery designs. This paper presents a flexible modeling methodology capable of predicting the steady state performance of various S-CO2 cycle configurations for both design and off-design ambient conditions, including part-load plant operation. The models assume supercritical CO2 as the working fluid for both a simple recuperated Brayton cycle and a more complex recompression Brayton cycle.

A Study of Supercritical Carbon Dioxide Power Cycle for Concentrating Solar Power Applications Using an Isothermal Compressor

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Jin Young Heo ◽  
Jinsu Kwon ◽  
Jeong Ik Lee
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Thermal Efficiency ◽  
Solar Power ◽  
Working Fluid ◽  
Brayton Cycle ◽  
Concentrating Solar Power ◽  
Power Cycle ◽  
Compressor Inlet ◽  
Supercritical Carbon

For the concentrating solar power (CSP) applications, the supercritical carbon dioxide (s-CO2) power cycle is beneficial in many aspects, including high cycle efficiencies, reduced component sizing, and potential for the dry cooling option. More research is involved in improving this technology to realize the s-CO2 cycle as a candidate to replace the conventional power conversion systems for CSP applications. In this study, an isothermal compressor, a turbomachine which undergoes the compression process at constant temperature to minimize compression work, is applied to the s-CO2 power cycle layout. To investigate the cycle performance changes of adopting the novel technology, a framework for defining the efficiency of the isothermal compressor is revised and suggested. This study demonstrates how the compression work for the isothermal compressor is reduced, up to 50%, compared to that of the conventional compressor under varying compressor inlet conditions. Furthermore, the simple recuperated and recompression Brayton cycle layouts using s-CO2 as a working fluid are evaluated for the CSP applications. Results show that for compressor inlet temperatures (CIT) near the critical point, the recompression Brayton cycle using an isothermal compressor has 0.2–1.0% point higher cycle thermal efficiency compared to its reference cycle. For higher CIT values, the recompression cycle using an isothermal compressor can perform above 50% in thermal efficiency for a wider range of CIT than the reference cycle. Adopting an isothermal compressor in the s-CO2 layout can imply larger heat exchange area for the compressor which requires further development.

Analysis of Advanced Supercritical Carbon Dioxide Power Cycles With a Bottoming Cycle for Concentrating Solar Power Applications

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Saeb M. Besarati ◽  
D. Yogi Goswami
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Solar Power ◽  
Waste Heat ◽  
Operating Conditions ◽  
Working Fluid ◽  
Brayton Cycle ◽  
Concentrating Solar Power ◽  
Working Fluids ◽  
Supercritical Carbon

A number of studies have been performed to assess the potential of using supercritical carbon dioxide (S-CO2) in closed-loop Brayton cycles for power generation. Different configurations have been examined among which recompression and partial cooling configurations have been found very promising, especially for concentrating solar power (CSP) applications. It has been demonstrated that the S-CO2 Brayton cycle using these configurations is capable of achieving more than 50% efficiency at operating conditions that could be achieved in central receiver tower type CSP systems. Although this efficiency is high, it might be further improved by considering an appropriate bottoming cycle utilizing waste heat from the top S-CO2 Brayton cycle. The organic Rankine cycle (ORC) is one alternative proposed for this purpose; however, its performance is substantially affected by the selection of the working fluid. In this paper, a simple S-CO2 Brayton cycle, a recompression S-CO2 Brayton cycle, and a partial cooling S-CO2 Brayton cycle are first simulated and compared with the available data in the literature. Then, an ORC is added to each configuration for utilizing the waste heat. Different working fluids are examined for the bottoming cycles and the operating conditions are optimized. The combined cycle efficiencies and turbine expansion ratios are compared to find the appropriate working fluids for each configuration. It is also shown that combined recompression-ORC cycle achieves higher efficiency compared with other configurations.

scholarly journals Impact of Fluid Substitution on the Performance of an Axial Compressor Blade Cascade Working with Supercritical Carbon Dioxide

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Carlos Tello ◽  
Alejandro Muñoz ◽  
David Sánchez ◽  
Timoleon Kipouros ◽  
Mark Savill
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Axial Compressor ◽  
Computational Design ◽  
Compressor Blade ◽  
Working Fluid ◽  
Local Flow ◽  
Variable Boundary ◽  
Turbomachinery Design ◽  
Supercritical Carbon

Abstract Recent research on turbomachinery design and analysis for supercritical carbon dioxide (sCO2) power cycles has relied on computational fluid dynamics. This has produced a large number of works whose approach is mostly case-specific, rather than of general application to sCO2 turbomachinery design. As opposed to such approach, this work explores the aerodynamic performance of compressor blade cascades operating on air and supercritical CO2 with the main objective to evaluate the usual aerodynamic parameters of the cascade for variable boundary conditions and geometries, enabling “full” or “partial” similarity. The results present both the global performance of the cascades and certain features of the local flow (trailing edge and wake). The discussion also highlights the mechanical limitations of the analysis (forces exerted on the blades), which is the main restriction for applying similarity laws to extrapolate the experience gained through decades of work on air turbomachinery to the new working fluid. This approach is a step toward the understanding and appropriate formulation of a multi-objective optimization problem for the design of such turbomachinery components where sCO2 is used as the operating fluid. With this objective, the paper aims to identify and analyze what would be expected if a common description of such computational design problems similar to those where air is the working fluid were used.

scholarly journals Impact of Fluid Substitution on the Performance of an Axial Compressor Blade Cascade Working With Supercritical Carbon Dioxide

2019 ◽  
Author(s):  
Alejandro Muñoz ◽  
David Sánchez ◽  
Mark Savill ◽  
Timoleon Kipouros ◽  
Carlos Tello-Castillo
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Axial Compressor ◽  
Computational Design ◽  
Compressor Blade ◽  
Working Fluid ◽  
Local Flow ◽  
Variable Boundary ◽  
Turbomachinery Design ◽  
Supercritical Carbon

Abstract Recent research on turbomachinery design and analysis for supercritical Carbon Dioxide (sCO2) power cycles has relied on Computational Fluid Dynamics. This has produced a large number of works whose approach is mostly case-specific, rather than of general application to sCO2 turbomachinery design. As opposed to such approach, this work explores the aerodynamic performance of compressor blade cascades operating on air and supercritical CO2 with the main objective to evaluate the usual aerodynamic parameters of the cascade for variable boundary conditions and geometries, enabling ‘full’ or ‘partial’ similarity. The results present both the global performance of the cascades and certain features of the local flow (trailing edge and wake). The discussion also highlights the mechanical limitations of the analysis (forces exerted on the blades), which is the main restriction to applying similarity laws to extrapolate the experience gained through decades of work on air turbomachinery to the new working fluid. This approach is a step towards the understanding and appropriate formulation of a multi-objective optimisation problem for the design of such turbomachinery components where sCO2 is used as the operating fluid. With this objective, the paper aims to identify and analyse what would be expected if a common description of such computational design problems similar to those where air is the working fluid were used.

Development of Turbine and Combustor for a Semi-Closed Recuperated Brayton Cycle of Supercritical Carbon Dioxide

2017 ◽  
Author(s):  
Takashi Sasaki ◽  
Masao Itoh ◽  
Hideyuki Maeda ◽  
Junichi Tominaga ◽  
Daizo Saito ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
New Technologies ◽  
Combined Cycle ◽  
Working Fluid ◽  
Brayton Cycle ◽  
The Usa ◽  
Demonstration Plant ◽  
Competitive Efficiency ◽  
Supercritical Carbon

Toshiba has been developing a turbine and a combustor for a semi-closed recuperated Brayton cycle of supercritical carbon dioxide called the Allam cycle, which is capable of both sequestrating 100% of carbon dioxide generated by combustion and providing electricity with competitive efficiency as the advanced combined cycle. The 25 MWe class demonstration plant with natural gas for this innovative cycle is being constructed in the USA by NET Power LLC and its operation is expected to be in 2017. Toshiba is going to provide the main components of its turbine and combustor. This paper describes the specification of the turbine and the combustor and consideration necessary to realize them in the first of a kind design condition of 30MPa with a supercritical carbon dioxide as its working fluid. This paper also describes some of the validation tests to realize new technologies before this turbine and combustor are installed and operated in the demonstration plant.

Off-Nominal Component Performance in a Supercritical Carbon Dioxide Brayton Cycle

2015 ◽  
Author(s):  
Eric M. Clementoni ◽  
Timothy L. Cox ◽  
Martha A. King
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Integrated System ◽  
Design System ◽  
Working Fluid ◽  
Brayton Cycle ◽  
Wide Range ◽  
Primary Driver ◽  
Atomic Power Laboratory ◽  
Supercritical Carbon

Bechtel Marine Propulsion Corporation (BMPC) is testing a supercritical carbon dioxide (S-CO2) Brayton system at the Bettis Atomic Power Laboratory. The Integrated System Test (IST) is a simple recuperated closed Brayton cycle with a variable-speed turbine-driven compressor and a constant-speed turbine-driven generator using S-CO2 as the working fluid designed to output 100 kWe. The main focus of the IST is to demonstrate operational, control, and performance characteristics of an S-CO2 Brayton power cycle over a wide range of conditions. Therefore, the IST was designed to operate in a configuration and at conditions that support demonstrating the controllability of the closed S-CO2 Brayton cycle. Operating at high system efficiency and meeting a specified efficiency target are not requirements of the IST. However, efficiency is a primary driver for many commercial applications of S-CO2 power cycles. This paper uses operational data to evaluate component off-nominal performance and predict that design system operation would be achievable.

An adaptive flow path regenerator used in supercritical carbon dioxide Brayton cycle

2018 ◽  
Vol 138 ◽  
pp. 513-522 ◽  
Author(s):  
Miao Ding ◽  
Jian Liu ◽  
Wen-Long Cheng ◽  
Wen-Xu Huang ◽  
Qi-Nie Liu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Flow Path ◽  
Brayton Cycle ◽  
Supercritical Carbon
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