Techno-economic Evaluation of Utility-Scale Power Plants Based on the Indirect sCO<sub>2</sub> Brayton Cycle - Report
6
Citation
0
Reference
10
Related Paper
Citation Trend
Abstract:
This report presents the results of a techno-economic analysis (TEA) of a coal-fired utility scale power plant based on the indirect supercritical carbon dioxide (sCO2) Brayton cycle using an oxy-fired circulating fluidized bed (CFB). A baseline plant configuration was examined as well as three variations to the sCO2 power cycle examining the impact of reheat (Rht), main compressor intercooling (IC), and a combination of reheat and main compressor intercooling (RhtIC). Each plant configuration was assessed at two turbine inlet temperatures of 620 °C and 760 °C.Keywords:
Brayton cycle
Cite
The aim of the work is to improve the quality with a decrease in the complexity of diagnosing an axial compressor
of a helicopter gas turbine engine with erosive-abrasive wear of its blades. Regularities of changes in the structural
and diagnostic parameters of the compressor depending on the operating time and the region of operation of the engine
are revealed. The values of the main gas-dynamic parameters and the wear of the compressor blades and the links
between them, which determine the limiting state of the TV3-117 type helicopter gas turbine engine, are substantiated.
A method for determining the residual life of the compressor is proposed, taking into account the region of operation
of the helicopter. The quality of compressor diagnostics was assessed using the gas-dynamic parameters of a helicopter
gas turbine engine in operation.
Axial Compressor
Cite
Citations (0)
Taking the gas turbine control system in a combined cycle power plant as the prototype,modeling as well as full scale simulation were carried out for the system with Matlab/Simulink.The simulation results match with the actual physical process well,and it notes that the model can be used for research on the gas turbine combined-cycle governing system.
Cite
Citations (0)
Abstract Supercritical carbon dioxide (sCO2) Brayton power cycles are typically designed to operate with compressor inlet conditions near the critical point to take advantage of the high density of the fluid at these conditions. While designing the cycle to operate here improves cycle efficiency, it also creates challenges for designing the compressor and predicting off-design compressor performance due to real gas fluid properties near the critical point. Multiple compressor performance map evaluation methodologies which incorporate real gas corrections have been proposed in literature with only limited evaluation of the accuracy of these methods compared to operational data from compressors designed for sCO2 power cycles. This paper evaluates compressor performance from the 100 kWe Integrated System Test (IST), which was operated at the Naval Nuclear Laboratory, over a range of compressor inlet conditions and rotational speeds relative to one real gas performance map correction methodology and assesses the impact of additional terms proposed in literature for improving the accuracy of off-design performance predictions.
Brayton cycle
Centrifugal compressor
Supercritical Carbon Dioxide
Cite
Citations (0)
Gas turbines in general and aircraft engines in particular undergo frequently dynamic operations.These operations include the routine start-up, load change and shut downs to cover their operation envelope.The frequency of the dynamic operation depends on the size of the engines and the field of application.Engines for commuter aircrafts and particularly helicopter engines operate more often in an off-design mode compared to large commercial aircraft engines and power generation gas turbines.During these routine operations, the compressor mass flow, the pressure ratio, the combustion chamber fuel and air mass flow as well as turbine mass flow change.These changes affect the engine aerodynamic performance and its efficiency.To avoid the inception of rotating stall and surge, high performance gas turbines are equipped with mechanisms that adjust the stator stagger angles thus aligning the stator exit flow angle to the rotor inlet angle, which reduces an excessive incidence.The reduction of incidence angle not only preserves the stable operation of the compressor, but it also prevents the compressor efficiency from deterioration.The existence of an inherent positive pressure gradient may cause the boundary layer separation on compressor blades leading to the rotating stall and surge.Such condition, however, does not exist in a turbine, and therefore, there has been no compelling reason to apply the blade adjusting method to the turbine component.For the first time, the impact of turbine blade stagger angle adjustment on the gas turbine efficiency during the operation is shown in this paper.Given a statistically distributed load condition, the extensive dynamic simulation reported in this paper shows how the efficiency can be positively affected through proper blade adjustment.For the time dependent operation, the code GETRAN developed by the author was enhanced to include the turbine blade adjustment as a function of time.To conduct the dynamic simulation with turbine stator stagger angle adjustment during a dynamic operation, the full geometry of the Brown Boveri GT-9 gas turbine was utilized.Starting from the reference stagger angle, it is varied within an incidence range of ± 3 degree.Detailed simulation results show the substantial efficiency improvement through stator stagger blade adjustment.
Cite
Citations (2)
Abstract The paper presents thermodynamic analysis of the gas-steam unit of the 65 MWe combined heat and power station. Numerical analyses of the station was performed for the nominal operation conditions determining the Brayton and combined cycle. Furthermore, steam utilization for the gas turbine propulsion in the Cheng cycle was analysed. In the considered modernization, steam generated in the heat recovery steam generator unit is directed into the gas turbine combustion chamber, resulting in the Brayton cycle power increase. Computational flow mechanics codes were used in the analysis of the thermodynamic and operational parameters of the unit.
Brayton cycle
Thermodynamic cycle
Rankine cycle
Cite
Citations (17)
The compressor is a key component in the supercritical carbon dioxide (SCO2) Brayton cycle. In this paper, the authors designed a series of supercritical CO2 compressors with different parameters. These compressors are designed for 100 MWe, 10 MWe and 1 MWe scale power systems, respectively. For the 100 MWe SCO2 Brayton cycle, an axial compressor has been designed by the Smith chart to test whether an axial compressor is suitable for the SCO2 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 SCO2. 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 SCO2 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 SCO2 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.
Brayton cycle
Centrifugal compressor
Axial Compressor
Stall (fluid mechanics)
Overall pressure ratio
Cite
Citations (32)
The paper introduces the development process of GE heavy gas turbine,existing problems of its F type compressor and the facility situation of domestic PG9351(FA+e) type gas turbines.Detailed analysis has been carried out on the existing problems.The improvement on each stage of compressor blades for the gas turbine is presented.
Industrial gas
Axial Compressor
Cite
Citations (0)
In this paper,differences between E class and F class gas turbines are presented,and a costeffectiveness comparison between combinedcycle plants respectively based on them are made. It is concluded that no matter in the performance of the turbine proper or in that of the combined cycle,F class gas turbines are superior to E class gas turbines;in the construction costs,power generation costs,operation and maintenance,the former are also superior to the latter. As a result,F class gas turbines are recommended for gas turbine power plants in preparation.
Cite
Citations (0)
In the paper,some questions about performance test of 9FA gas turbine combined cycle plant such as combined cycle equipment performance curves,performance test of HRSG,responsibility apportion have been analyzed,the author's opinion will provide the valuable information and ideas for those who engaged in performance test of gas turbine single shaft combined cycle plant.
Thermodynamic cycle
Cite
Citations (0)
In general, two approaches have been used in the gas turbine industry to improve Brayton cycle performance. One approach includes increasing Turbine Inlet Temperature (TIT) and cycle pressure ratio (β), but it is quite capital intensive requiring extensive research and development work, advancements in cooling (of turbine blades and hot gas path components) technologies, high temperature materials and NOx reducing methods. The second approach involves modifying the Brayton cycle. However, this approach did not become very popular because of the development of high efficiency gas turbine (GT) based combined cycle systems in spite of their high initial cost. This paper discusses another approach that has gained lot of momentum in recent years in which modified Brayton cycles are used with humidification or water/steam injection, termed “wet Cycles”, resulting in lower cost/kW power system, or with fuel cells, obtaining “hybrid Cycles”; the cycle efficiency can be comparable with a corresponding combined cycle system including better part-load operational characteristics. Such systems, that include advanced Steam Injected cycle and its variants (STIG, ISTIG, etc.), Recuperated Water Injection cycle (RWI), humidified air turbine cycle (HAT) and Cascaded Humidified Advanced Turbine (CHAT) cycle, Brayton cycle with high temperature fuel cell, Molten Carbonate Fuel Cell (MSFC) or Solid Oxide Fuel Cells (SOFC) and combinations of these with the modified Brayton cycles, have not yet become commercially available as more development work is required. The main objective of this paper is to provide a detailed parametric thermodynamic cycle analysis of the above mentioned cycles and discussion of their comparative performance including advantages and limitations.
Brayton cycle
Rankine cycle
Thermodynamic cycle
Ram air turbine
Overall pressure ratio
Cite
Citations (3)