Turbine Flow Research Articles

LOSS BREAKDOWN IN AXIAL TURBINES: A NEW METHOD FOR VORTEX LOSS AND WAKE DETECTION FROM 3D RANS SIMULATIONS

Abstract To enhance turbine efficiency, it is essential to mitigate the losses generated by irreversible phenomena in turbine flows, including boundary layers, shock waves, vortices, and trailing edge wakes. Fast and accurate detection of losses is crucial from the earliest design stages, where reduced-order models based on oversimplified correlations are employed. This requires a deep understanding of the physics behind loss-generating mechanisms, attainable by examining the 3D flow. While existing criteria can identify various phenomena, accurately quantifying vortex-generated losses remains challenging, as these losses frequently extend beyond the vortical structure. This paper provides a straightforward and effective approach to localize and assess vortex-related losses. The method is grounded in Zlatinov's decomposition of the entropy generation rate into a streamwise and secondary flow component. A criterion based on vortex kinematics evaluates the vortex's strength, enabling the determination of its spatial influence and contribution to overall losses. To validate the method, a post-processing code is developed to perform loss breakdown, using existing identification criteria and new techniques introduced within this work, particularly for wake detection. 3D RANS simulations on various configurations, from simple curved ducts to nozzle guide vanes, allow to gradually test and validate the computational tool. Results confirm that the highest entropy generation rates occur outside the vortical structure and show good ability to identify both the vortex shape and its area of influence in terms of losses. A significant improvement in predicting vortex losses is observed, especially for turbine blades with leakage vortices.

Mathematical modeling for the efficiency function of the Retiro small hydroelectric power plant turbine-generator set

ABSTRACT Many authors use an efficiency constant for the turbine-generator set to calculate energy generation in hydroelectric projects. This often does not reflect reality because the efficiency of this system is relative and is related to the potential of the net head height and the flow of turbine discharge. The present work aims to perform a mathematical modeling for an analysis of the efficiency of the Turbine-Generator Small Hydroelectric Power Plant (SHPP) Retiro. To perform this analysis, a model based on a second-degree polynomial function was employed. A multivariate regression technique was applied by the Least Square Method (LSM) to obtain the coefficients of the function. To verify the behavior of the measured and adjusted data, the Determination Coefficient (R2) of Root Mean Square Error (RMSE) algorithm was applied. The RMSE Mean of 0.022 and the RMSE Std of 0.029 suggest that the second-degree polynomial function is more consistent and stable across different training and validation datasets. The R2 value of 0.993 indicates that 99.3% of the variability in the data is explained by the model. The Omnibus, Durbin-Watson, and Jarque-Bera tests were applied to diagnose potential issues related to normality, autocorrelation, and adequacy, thereby validating the accuracy and significance of the model. The Hessian matrix technique was also used to verify the critical points of the function. The critical point corresponding to a water head of 11.47 meters and a turbine flow of 145.1 m3/s presented the highest operational efficiency. This study allows presenting a turbine efficiency function, its Hill Curve and a generator efficiency function with its corresponding Efficiency Curve. For efficiency analysis in several flow, height and power settings. The technique has proved efficient and can be an applicable tool in energy parameter studies for other hydroelectric projects with the same characteristics as SHPP Retiro.

Understanding of the asymmetric twin-stroll radial turbine under steady and pulsating inlet conditions

Utilize asymmetrical twin-scroll turbines (ATSTs) to achieve high-pressure exhaust gas recirculation (EGR) with a single scroll while optimizing the other scroll’s design for engine scavenging optimization. ATST performance prediction relies heavily on understanding the turbine flow mechanism, which always faces the challenge posed by time-dependent non-uniform intake. This paper studied its performance and flow field under steady and unsteady intake conditions for a production ATST. Firstly, the steady performance of the ATST with different asymmetries (ASYs) under different scroll pressure ratios (SPRs) is investigated via the computational fluid dynamics (CFD) method. Results demonstrate that the distribution relationship between SPR and turbine flow parameter (MFP) has a certain symmetry based on SPR = 1. For efficiency, the imbalance of inlet conditions will lead to the reduction of turbine efficiency. Moreover, the ASY has little effect on the turbine’s efficiency under the condition of SPR = 1. Also, the unsteady CFD simulations are conducted under pulsating inlet conditions with different scroll averaged pressure ratios (SAPRs). The results show that the highest efficiency was achieved at an ASY of 0.5 under a SAPR of 1.2 conditions, and the maximum, minimum, and average efficiencies were 1.9%, 1.5%, and 0.9% higher than those at an ASY of 0.83. The turbine’s flow field at the optimal incidence angle point is analyzed. The secondary flow vortex in the volute of an ASY of 0.5 is more robust, and the volute outlet ‘s total pressure loss is more significant. However, a relatively good incidence angle is obtained at the rotor inlet, and the loss in the rotor flow field is more minor. Therefore, the turbine efficiency with an ASY of 0.5 is higher.

Effect of Different Nozzle Arrangements on Combustion Flow Characteristics in a Swirl Coupling Multiple Direct Injection Combustor

ABSTRACT The influence of multiple direct injection nozzle arrangements with hexagonal, rhombus, and circular shapes on the combustion flow in gas turbines was numerically studied, and the combustion flow characteristics of swirl combustion combined with multiple direct injection combustion were analyzed, such as velocity and temperature distribution, vortex structure, NOX (nitrogen oxides) emission, flame stretch rate, etc. The result shows that for these different nozzle arrangements, the difference in velocity and temperature distribution is not obvious, but the difference in vortex structure is large. The hexagonal arrangement can form several counter-rotating vortex pairs (CVP) near the side wall, the rhombus arrangement can form several deflection vortex structures outside the center swirl, and the circular arrangement forms the least vortex structure. Furthermore, the circular arrangement is most effective in reducing the non-uniformity of the outlet temperature, OTDF is 0.00548, and it has a higher flame stretch rate, which means that it has a higher combustion intensity. However, the hexagon arrangement has the higher NOX emission, reaching 3.16 ppm.

Numerical study on flow and heat transfer of combustion chamber and turbine under thermal shock test

In order to more accurately analyze the influence of the interaction between the aero-engine combustion chamber and the turbine, this paper establishes a combustion chamber-turbine cross-component model based on a high-pressure first-stage guide vane thermal shock test device for numerical research. The SST k-ω turbulence model, non-premixed combustion model and P1 radiation model are selected, and the test conditions are used as boundary conditions to carry out fluid-solid coupling unsteady calculation in ANSYS FLUENT. The numerical results are in good agreement with the experimental results. The complex flow field information between the combustion chamber and the turbine is obtained by analyzing the numerical results. It is found that there is an interaction between the combustion chamber and the turbine. The results show that the hot spot at the outlet of the combustion chamber will cause a stronger thermal shock to the downstream of the high-pressure first-stage guide vane during the migration process. The influence of the high-pressure first-stage guide vane on its upstream can be traced back to the position 0.3 times the chord length from the outlet of the combustion chamber.

Electricity Generation at Gas Distribution Stations from Gas Surplus Pressure Energy

At gas distribution stations (GDSs), the process of throttling (pressure reduction) of natural gas occurs on gas pressure regulators without generating useful energy. If the gas expansion process is created in a turbine, to the shaft where an electric generator is connected, then electricity can be obtained. At the same time, the recycling of secondary energy resources is provided, which is an important component in the efficient use of natural resources. The obtained electric power can be supplied to the external power grid and/or used for the GDS’s own needs. The process of generating electricity at the GDS from gas overpressure energy is an environmentally friendly, energy-saving technology that ensures an uninterrupted, autonomous operation of the GDS in the absence of an external energy supply. The power needs of a GDS with regard to electricity are relatively small (5 ÷ 20 kW). Expansion in throttling devices or turbine flow paths leads to gas cooling with a possible hydrate formation. It is prevented via gas preheating or vortex expansion equipment that keeps the further gas temperature at a necessary level. Turbogenerators can be created on the basis of vortex expansion turbomachines, which have many advantages compared to turbomachines of other types. This article studies how gas pressure (outlet: gas distribution station) and gas preheating (inlet: vortex expansion machine) influence turbogenerator parameters. Nine turbogenerator variants for the power needs of gas distribution stations have been assessed.

Effect of Atmospheric Stability on Meandering and Wake Characteristics in Wind Turbine Fluid Dynamics

This study investigates the impact of atmospheric stability on wind turbine flow dynamics, focusing on wake deflection and meandering. Using the high-fidelity large-eddy simulation coupled with the Actuator Line model, we explore three stability conditions for the Vestas V80 turbine, both with and without yaw. The results indicate that wake meandering occurs predominantly along the deflected wake axis. Despite varying wake deficits and meandering behaviors, neutral and stable conditions exhibit similar wake deflection trajectories during yawed turbine operations. Spectral analysis of meandering reveals comparable cutoff and peak frequencies between neutral and stable cases, with a consistent Strouhal number (St=0.16). The unstable condition shows significant deviations, albeit with associated uncertainties. Overall, increased stability decreases both oscillation amplitude and frequency, highlighting the complex interplay between atmospheric stability and wind turbine wake dynamics.

Effect of hills on wind turbine flow and power efficiency: A large-eddy simulation study

This study investigates the influence of topography on wind turbine flow and power efficiency. Specifically, a standalone wind turbine is positioned at the top of idealized two-dimensional hills, and the effects of hill geometry and turbine position are systematically investigated. Various parameters are studied, including hill slope, distance between the leeward side of the hill and the turbine, turbine hub height, and hill size. Overall, it is observed that the turbine wake is consistently stronger in the hill cases compared to the flat case. This is attributed to two characteristics of hill flows: (1) the negative streamwise velocity gradients on the leeward side of the hills and (2) the reduced turbulence above the hilltops and hill wake regions. In addition, it is observed that the turbine induction factor is consistently increased in the hill cases compared to the flat case, while the turbine power and thrust coefficients are reduced. In practice, this means that turbines on the hills produce less power output than those on flat terrain for an equivalent wind potential, with the potential decrease in power output reaching more than 20% for certain cases. Altogether, the results offer new insights into the effect of topography on turbine power efficiency. In addition, the study identifies clear relationships between the turbine power coefficient, the induction factor, the overall maximum deficit, and the base flow pressure gradient. These relationships could potentially be used to predict the change in power efficiency based on the wake flow or the base flow. Overall, the results show a clear connection between the turbine power efficiency and the turbine wake development.

Operation Scheme analysis of a multipurpose small modular reactor under cogeneration condition based on a once-through steam generator dynamic model

Highly flexible load requirements and cogeneration economy need to challenge the operation of a multipurpose small modular reactor cogeneration plant with once-through steam generators. Therefore, the present study develops a once-through steam generator dynamic model to analyze the multipurpose small modular reactor operation scheme under cogeneration conditions at different power levels. The once-through steam generator dynamic model is derived based on conversation equations using the moving boundary method. It is verified with RELAP5 results and open literature and the maximum relative error is 3.21 %. Three operation schemes are proposed for multipurpose small modular reactor cogeneration operation: Scheme 1 with constant steam pressure and average coolant temperature, Scheme 2 with constant steam temperature and pressure, and Scheme 3 with constant steam temperature and pure sliding steam pressure. Steady-state and dynamic characteristics with three operation schemes are simulated and investigated at three power levels: 100 %, 70 % and 30 %. The steady-state results show that Scheme 1 is more favorable for the primary loop, while Scheme 2 is beneficial to the secondary loop, and Scheme 3 can improve the thermal efficiency at low power level. The transient findings indicate that disturbances from the reactor side have a significant impact on the once-through steam generator and the minimum settling time is 3.3 s. Consequently, steam temperature control of once-through steam generator is achieved by regulating the control rods for Schemes 2 and 3, while steam pressure is suggested to be controlled by the feedwater valve for Scheme 1. For cogeneration conditions at 70 % power level, Scheme 2 can achieve the highest steam flow of turbine, the highest steam flow of steam extraction and the smallest steam specific volume, which are 87.88 kg·s−1, 28.96 kg·s−1, and 0.0503 m3·kg−1, respectively. Scheme 2 is recommended for high power levels under cogeneration operation. In contrast, Scheme 1 is more suitable for the condensing unit operation for low power levels.

Synchronous PIV measurements of a self-powered blood turbine and pump couple for right ventricle support

A blood turbine-pump system (iATVA), resembling a turbocharger was proposed as a mechanical right-heart assist device without external drive power. In this study, the iATVA system is investigated with particular emphasis on the blood turbine flow dynamics. A time-resolved 2D particle image velocimetry (PIV) set-up equipped with a beam splitter and two high speed cameras, allowed simultaneous recordings from both the turbine and pump impellers at 7 different phased-locked instances. The iATVA prototype is 3D printed using an optically clear resin following our earlier PIV protocols. Results showed that magnetically coupled impellers operated synchronously. As the turbine flow rate increased from 1.6 to 2.4 LPM, the rotational speed and relative inlet flow angle increase from 630 to 900 rpm, and 38 to 55% respectively. At the trailing edges, backflow region spanned 3/5 of the total passage outlet flow, and an extra leakage flow was observed at the leading edge. For this early turbine design, approximately, 75% of the turbine blade passage was not contributing to the impulse operation mode. The maximum non-wall shear rate was ~ 2288 s−1 near to the inlet exit, which is significantly lower than the commercial blood pumps, encouraging further research and blood experiments of this novel concept. Experimental results will improve the hydrodynamic design of the turbine impeller and volute regions and will be useful in computational fluid dynamics validation studies of similar passive devices.

A Comparative Study between Theoretical and Measured Performance of Standard Centrifugal Pumps Running as Turbines

High cost of custom-made conventional turbines and the lack of local manufacturing facilities have created significant obstacles to the development of Pico/micro hydroelectric schemes in the country. In this context it has been identified pump as turbine (PAT) electric schemes can have distinct advantages over conventional turbines because pumps are manufactured locally at mass scale and available in various sizes. But not all pumps are suitable for use as PAT because they have different design details and manufacturing qualities. The performance of a pump used as a turbine is assessed based on two primary parameters: turbine mode head and flow at the Best Efficiency Point (BEP). There are various methods available in the literature for predicting PAT theoretical head and flow at BEP. These methods aim to estimate how the pump will perform when used as a turbine. Despite these prediction methods, there is a consistent deviation of approximately ±20% between the theoretical estimates and the actual measured performance. This indicates that real-world conditions and factors not accounted for in theoretical models can significantly affect the performance of PAT systems. The primary objective of the present study was to measure the deviation between the actual performance and the predicted performance of two PAT systems in terms of head and flow at BEP. This deviation was then compared to the commonly mentioned figure of ±20% in the literature. The study focused on using what it considered to be the most accurate prediction method among those presented in the literature to estimate PAT head and flow at BEP and involved running reverse, 1.1 kW, and 1.6 kW direct-drive standard centrifugal type water pumps in a test rig to measure the actual performance of the two PATs. The results of the study showed a deviation of +27% and -22% between the actual measured head and flow at BEP, and the values predicted by the theoretical method. This deviation is slightly outside the commonly mentioned range of ±20% found in the literature, but this is not expected to have a detrimental effect on the generation of electric power. This implies that, even with the observed slight deviation, the prediction method used in this study can be satisfactorily employed to estimate PAT head and flow at BEP.

Hydrodynamic performance analysis of dual vertical axis turbine

Abstract This article adopts a biomimetic approach and uses the profile of the fastest sailfish in the ocean as the airfoil profile of a water turbine. Integrating centrifugal and axial flow turbines on one drive shaft can effectively integrate wave and current energy (wave current integration). The wake of a centrifugal turbine flows into the flow field of an axial flow turbine, and based on the Kantar effect, the energy harvesting coefficient of the axial flow turbine is improved. The five blades of the axial flow turbine and centrifugal turbine are subjected to uneven forces, resulting in torsional and radial forces on the drive shaft, causing periodic series motion of the turbine and reducing the overall lifespan of the machine.

Analysis of Micro Hydro Potential as A New Renewable Energy Source

Electricity demand in Indonesia is currently increasing along with population growth, economic growth, and development. This increase can lead to an energy crisis if it is not accompanied by the provision of additional power plants. This study aims to analyze the micro-hydro potential located at Bangkong Waterfall, Kuningan Regency. The research uses a quantitative approach that begins with field surveys and data collection from relevant agencies. Next, the dependable discharge analysis uses the Thiessen polygon method based on rainfall data and watershed area, as well as flow discharge analysis using the rational method. The results of calculations using the Thiessen polygon method and the rational method yield Q80 with a minimum discharge of 0.009 m³/d and a maximum discharge of 1.160 m³/d. For direct discharge analysis, the Float method is used to calibrate the calculation results with field conditions. The direct discharge analysis using the Float method yields 0.32 m³/d. Based on the efficiency considerations of the micro-hydro power plant (MHPP) components such as a head of 20 meters, turbine type efficiency, water density, gravity factor, and flow discharge in the pipe of 0.109 m³/d, the potential power that can be generated at the Bangkong Waterfall micro-hydro power plant is 16,097.23 Watts or 16.097 Kilowatts.

An Investigation on Exhaust Pulse Characteristics of Asymmetric Twin-Scroll Turbocharged Heavy-Duty Diesel Engine

<div>The shape and energy distribution characteristics of exhaust pulse of an asymmetric twin-scroll turbocharged engine have a significant impact on the matching between asymmetric twin-scroll turbines and engines, as well as the matching between asymmetric twin scrolls and turbine wheels. In this article, the exhaust pulse characteristics of an asymmetric twin-scroll turbocharged engine was studied. Experiments were conducted on a turbine test rig and an engine performance stand to determine the operation rules of exhaust pulse strength, turbine flow parameters, turbine isentropic energy, and turbine efficiency. The results showed that the exhaust pulse strength at the inlets of both the small and large scrolls continuously decreased with the increase of engine speed. And the flow parameters at the inlets of the small and large scrolls exhibited a “ring” or “butterfly” shape with the change of expansion ratio depending on the pressure deviation of the extreme points at the troughs on both sides of the “secondary peak” of the exhaust pressure pulse, respectively. Besides, the distribution trend of turbine isentropic power was consistent with the trend of exhaust pressure pulse at the inlets of the small and large scrolls. Furthermore, when opening the balance valve, it caused the appearance of “concave” and “convex” features near the “main peak” and “secondary peak” of the turbine isentropic power pulses, respectively. Finally, as the engine speed increased, the fluctuation of turbine instantaneous efficiency gradually decreased. When calculating the instantaneous efficiency of the turbine, the influence of the rotor’s rotational inertia needs to be considered, otherwise, there may be a false phenomenon of exceeding 100% efficiency.</div>

Numerical Investigation on the Influence of Continuous Rotating Backpropagation Pressure Wave on Turbine Performance

Abstract Researches have shown that the use of a continuous detonation afterburner can improve the propulsion performance of aero engine. However, backpropagation pressure waves (BPW) generated by the pressure gain of detonation will affect the internal flow and performance of turbine. This article simulates BPW through a custom function, and investigates the effects of BPW amplitude, rotation frequency, and propagation mode on turbine performance through three-dimensional simulation. The results show that as the pressure amplitude of the BPW increases, the pressure oscillation at each section of the turbine increases and a local subcritical flow state will appear, leading to the decrease of turbine flowrate and turbine power, as well as an intensification of instantaneous turbine power fluctuations. As the rotation frequency of the BPW increases, the pressure oscillation at each section of the turbine gradually decreases. The flowrate and power of the turbine do not change much, but turbine efficiency gradually decreases. Compared to the aligned mode, the turbine performs better under the influence of BPW in misaligned mode. Compared to the single-wave mode, the fluctuation of transient turbine power is lower under the influence of BPW in the multiwave mode excluding collision mode. Finally, the constraints of equal flowrate region and equal turbine power line on the peak-to-peak value of the BPW were analyzed when the joint operation of the turbine and compressor was not affected. The rotation frequency and mode of BPW will affect the flowrate region and power line.

A Numerical Study on Effects of Ice Formation on Vertical-axis Wind Turbine Performance and Flow Field at Optimal Tip Speed Ratio

A Numerical Study on Effects of Ice Formation on Vertical-axis Wind Turbine Performance and Flow Field at Optimal Tip Speed Ratio

Design, optimization, and performance analysis of a subsonic high-through flow turbine

This paper presents the design method and numerical analysis results of a two-stage high-through flow (HTF) high-pressure turbine. Compared to conventional design principles, the HTF turbine proposed in this study is a kind of high flow coefficient turbine. This design scheme enables the turbine to effectively increase the output power and thrust while maintaining the same windward area. At the design speed, the pressure ratio of the HTF turbine is 3.8, with an adiabatic efficiency of 91.46%. The flow coefficients of the first and second stage are 0.76 and 0.86, respectively, and the loading coefficients are 2.55 and 1.47. Detailed design parameters, flow characteristics, and aerodynamic performance are presented in this paper. Based on the preliminary design result, the second stage turbine was optimized for a wide range of operating conditions. The computational fluid dynamics simulation results show that compared with the traditional turbine, the loading form of the HTF turbine changes from aft-loaded to front-loaded. In addition, there is a certain increase in tip leakage of the turbine. This study achieves high efficiency, while increasing the turbine flow rate, and provides a corresponding reference for the design method of improving turbine flow capacity.

Sensitivity analysis of turbine stage aerothermal characteristics and blade cooling performance considering combustor swirl and hot spot

This paper investigates the global sensitivity of high-pressure-turbine (HPT) first stage cascades aerothermal characteristics and blade cooling performance under the influence of combustor swirl and hot spot. The combustor outflow conditions impact on turbine working performance and robustness. This paper is focused on the influence of uncertain combustor swirling flow and hot spot, rather than deterministic working conditions. A simplified combustor outflow simulation method is firstly proposed, and the effects of combustor outflow are quantified by combining chaos polynomial expansion with Sobol’ decomposition method. The results show that different rotating directions of the swirl lead to restricted influences on the averaged aerothermal performance of the turbine stage, but significantly affects its robustness. The positive swirl increases the total pressure loss generated by the lower passage vortex of the stator cascade, and the high uncertainty region of the stator cascade total pressure loss profile is the combined products of the residual swirl and the interaction between the passage vortex and mainstream. The total pressure loss of the rotor cascade due to leakage vortex has low sensitivity to the hot spot and swirl strength, while the total pressure loss generated by the passage vortex is affected by hot spot temperature. Temperature distribution affected by the passage vortex is sensitive to swirl strength. Generally, uncertainty variance of stage aerothermal parameters with positive swirl is about 30% larger than that of the negative case, since the positive swirl has stronger interactions with the blades, leading to more significant uncertainty. However, the averaged heat transfer coefficients with positive swirl are 37% less sensitive, compared to the negative swirl case. The results give better understanding on the influence mechanisms of turbine inflow conditions, emphasize the meaning of investigating uncertain characteristics of the turbine cascades. Investigations of this article provide reference for robust turbine blade cooling design.

Development of numerical and experimental performance evaluation techniques for high-reliability turbine flow meters of ice-making water-dispenser

A turbine flowmeter for sensing the water supply in an ice-making system of a refrigerator requires high sensitivity to the flow rate. This research aims to develop a comprehensive performance evaluation technique by constructing an experimental setup and establishing a numerical technique to simulate the rotational motion of the impeller in response to the injection of water into the flowmeter. An experimental rig was built to secure the measurement accuracy according to the fluid temperature and pressure changes and verify the reliability under various flow conditions from low to high. A numerical method based on the six-degree of freedom method was used to confirm its validity, which is different from a moving reference frame, which numerically analyzes the rotational speed of the turbine by backtracking the rotational speed to correspond to the flow conditions by giving it a constant rotational speed. By simulating water injection into the flowmeter, generating kinetic energy in the impeller according to the flow rate, and subsequently rotating the impeller due to the generated torque, the numerical analysis cost was reduced, allowing direct numerical analysis of the impeller’s acceleration motion. The results were evaluated in terms of angular velocity and pulse signal, and the applicability and reliability of the numerical technique were verified by comparing the numerical results with experimental results. The aerodynamic performance of the impeller was analyzed to understand the phenomena as the impeller rotates. The results of this study can be utilized to conduct future research to improve the performance of flow meters, thus proving its value as a preliminary study.

Comprehensive analysis of carbon emission reduction technologies (CRTs) in China's coal-fired power sector: A bottom-up approach

Carbon dioxide (CO2) reduction technologies (CRTs) in the coal-fired power sector play an imperative role in the mitigation of environmental challenges and reducing CO2 emissions to help achieve the 2 °C target. However, a compelling necessity persists for a unified framework that can effectively and accurately estimate the costs and potentials associated with CRTs, arising from the diversity of technologies and unit types. Therefore, this study employs a bottom-up approach to analyze the costs and potential of 25 advanced CRTs in the coal-fired power sector, excluding CO2 capture, utilization and storage (CCUS), across 19 types of coal-fired power units. This analysis amalgamates the CO2 reduction supply curve (CRSC) approach with levelized cost of CO2 reduction (LCOC) and a broken-even analysis which could reflect the sector's average carbon reduction cost. The outcomes reveal the following key insights: (1) These technologies collectively harbor a substantial CO2 conservation potential amounting to 925.61 Mt CO2, with a broken-even price of CNY 410.1/tCO2. This reduction could potentially lower 20%–25 % of CO2 emissions in China's power system in 2022, highlighting the crucial role of CRTs in achieving a low-carbon transition and national climate targets; (2)Steam turbine flow path retrofit (T8) not only offers a relatively high CO2 reduction potential (>60 Mt CO2), but also features a low cost (<CNY 150/tCO2) and high profit (>CNY 0.85/MWh). Prioritizing the development of this technology can significantly accelerate the low-carbon transition of coal power; (3) Carbon price have a paramount influence on the cost-effectiveness of CRTs and driving their adoption.