Considering the characteristics of high efficiency and zero carbon emissions of the semi-closed CO₂ cycle, and based on the semi-closed CO₂ power generation system integrated with liquefied natural gas (LNG) cold energy at present, an efficient utilization way of LNG cold energy was proposed. Results show that, for the base case, the energy consumptions of the air separation and compression processes are reduced by 70.4 and 75 MW, respectively, and with a net system efficiency of 63.76%, which is 9.48 percentage points higher than the conventional cycle. Furthermore, with optimization measures such as improving the system parameters and matching the heat capacities of regenerators, the net efficiency of the optimized case is further increased to 72.22%, and the exergy efficiency is 51.27%. Compared with the reference system Ⅱ of only integrating LNG cold energy within the power cycle, the exergy efficiency of cold energy utilization is improved by 28 percentage points.

Heavy-duty gas turbine is a kind of efficient thermo-mechanical conversion equipment so far, with the combined cycle efficiency higher than 60%. As gas turbines have excellent peak shaving capability, they will play an increasingly important role in the new power network based on new energy. An overview of the working characteristics, the structural features and main technical parameters of heavy-duty gas turbine compressors were introduced. The development and technical progress of typical gas turbine compressors from major international original equipment manufacturers were reviewed. The research progress of compressor design system was summarized. Considering the development of advanced heavy-duty gas turbine technology, key technology development directions were proposed, including aerodynamic layout optimization, high performance airfoil, full 3D design of transonic stages and highly integrated design system, based on the development status of heavy-duty gas turbines in China.

By dividing the incident solar spectrum into bands, an integrated photovoltaic (PV) and photothermal (PT) driven organic Rankine cycle (ORC) was established. Thermodynamic analysis of the system was conducted under the temperature limit of 100 ℃ for the cooling panel, to identify suitable working fluids for the ORC system and optimize the evaporation temperature. Results show that isobutene as the cooling fluid for the photovoltaic system and the working fluid for the ORC system, the highest system efficiency can be achieved. Frequency division technology transfers the heat dissipation load of the cooling panel to the collector, which can reduce the cooling demand of the photovoltaic panel and thus reduce the mass flow rate of the working fluid. It has a positive effect on improving the system's power generation capacity, and can enhance the efficiency of pure photovoltaic electricity generation by 9%. Additionally, frequency division efficiency and the absorption band of solar cells significantly impact the overall efficiency of the integrated power supply system.

The prospective demand for carbon reduction requires gas turbine combustion chambers to control NO_x emissions, improve power regulation range and fuel adaptability while outlet temperatures are continuously increasing. To address the above challenges, gas turbine manufacturers are developing axial staged combustion technology. This paper firstly introduced the principle of axial staged combustion and analyzed the effects of axial staged parameters, jet-in-crossflow flame morphology, nozzle geometry and fuel type on pollutant emissions and combustion instability. Existing studies show that reducing the equivalence ratio of the primary combustion chamber and enhancing the mixing uniformity of the secondary stage primary combustion chamber can reduce pollutant emissions. The thermoacoustic oscillation of axial staged combustion chambers is complex, and could be inhibited by a reasonable selection of stage parameters. The emission reduction benefits and part-load flexibility of axial staged combustion chambers have been verified in commercial operation. Based on the current research status, key issues and future research directions of axial staged combustion technology are proposed.

Due to the complexity of turbulent flow problems for film cooling, the traditional Reynolds average Navier-Stokes (RANS) method tends to underestimate the intensity of turbulent thermal diffusion, leading to inaccurate prediction of cooling effectiveness. A framework based on physics-informed neural network (PINN) was therefore proposed, and a data-driven neural network model of turbulent Prandtl number was built based on RANS flow data and large eddy simulation(LES) temperature data. After implementing this model into a RANS solver, the intensity of turbulent thermal diffusion could be adjusted dynamically and a temperature distribution highly consistent with LES results was obtained. Results show that PINN is an effective method to build a data-driven turbulence model and modeling of turbulent Prandtl number can effectively improve the accuracy of RANS temperature prediction.

In order to realize stable, efficient and environmentally friendly coordination of waste incinerator power generation units, multi-objective optimization was conducted for combustion process of the incinerator. A dynamic modeling method combining extreme learning machine (ELM) and nonlinear autoregressive moving average model with exogenous inputs (NARMAX) was proposed, and the parameters of the model are optimized by improved sparrow algorithm (ISSA). The dynamic models of steam flow, boiler efficiency and first flue temperature of the incinerator were established respectively. The ISSA-ELM-NARMAX model was compared with the traditional BP neural network model, ELM-NARMAX model and SSA-ELM-NARMAX model. Finally, multi-objective optimization of the combustion process was carried out to find the optimal operating parameters of the incinerator based on the improved non-dominated sorting genetic algorithm (NSGA-II). Results show that the dynamic model of combustion process of the incinerator based on ISSA-ELM-NARMAX is more accurate and effective, and the proposed control strategy can provide operational guidance for the incinerator operators.

To explore the deep peak shaving capacity of coal-fired boilers, the hydrodynamic force and wall temperature characteristics of the water-cooled wall of a supercritical 630 MW boiler were studied. Mathematical models of the hydrodynamic force and wall temperature characteristics were established, and water-cooled wall pressure drop, flow distribution, outlet working substance temperature and wall temperature distribution along the furnace height between 20% and 30% boiler maximum continuous rating (BMCR) loads were analyzed. Results show that, the helical tube sections of the water-cooled wall exhibit small thermal deviation and uniform heat load distribution under 20% and 30% BMCR loads. The outlet steam temperature deviation of the vertical tube sections of the water-cooled wall is large, and the over-temperature is more likely to occur in this area. Under 30% BMCR load, the boiler could operate safely in dry state condition. Under 28.8% BMCR load, the inlet water temperature of the water-cooled wall is 280.0 ℃, and the maximum wall temperature of the water-cooled wall in dry state condition exceeds 450.0 ℃. Under 27.3% BMCR load, the maximum wall temperature of the water-cooled wall in dry state condition exceeds 500.0 ℃, and the boiler should operate in wet state condition or the wall temperature should be reduced by adjusting the inlet water temperature.

Vacuum gas nitriding process was applied to strengthen the surface of the SP-700 titanium alloy at different temperatures. The surface morphology, cross-sectional morphology, hardness, abrasion resistance and electrochemical corrosion performance of the newly formed gas-nitrided layers were investigated using scanning electron microscope (SEM), optical microscope (OM), micro-Vickers hardness tester, reciprocating friction and warm damage tester, white light interference three-dimensional surface profiler and electrochemical workstation, respectively. The corrosion behavior of the gas-nitrided layers was determined by immersion corrosion method in HF solution. Results show that, the microstructural morphologies of the gas-nitrided layers are significantly influenced by the processing temperatures. With the increase of temperature, the amount of nitride increases and the nitride layer becomes denser. The hardness of the high-temperature gas-nitrided layer was about 1.9 times higher than that of the matrix, and the relative abrasion resistance can reach 51.34. All samples can be passivated spontaneously in 3.5% NaCl solution, indicating their good electrochemical corrosion resistance. The samples with gas-nitrided layer perform better in HF corrosion solution, and the higher the processing temperature, the better the corrosion resistance of the samples.

In order to optimize the overall power output and fatigue load of the wind farm, an optimization method of wind turbine yaw angle group was proposed. A neural network judgment model for wind turbine wake interference was established, and the relative coordinates of the wind turbine and the incoming wind speed were taken as characteristic values, to determine whether there was wake interference between the fans. The connected component decomposition algorithm was introduced to divide the wind farm into multiple aerodynamic decoupling groups without wake interference. With the goal of increasing power and suppressing load, the improved adaptive evaluation particle swarm algorithm was used to optimize all swarms in parallel. Results show that compared with the greedy algorithm and the overall optimization method, the group optimization method has better effects on power improvement and load suppression, and its stability is better.

A power generation system with pre-combustion CO₂ capture based on staged coal gasification and chemical recuperation was proposed to achieve high-efficiency and low-carbon power generation from coal. The system decoupled the coal gasification process into two stages: a pyrolysis stage at 600 ℃ and a gasification stage producing syngas at 1 400 ℃. The exhaust heat from gas turbines was used to drive pyrolysis, and in addition, the sensible heat of syngas was used to drive pyrolysis gas reforming. The thermodynamic performance of the present system was compared with the reference system, and the effect of different key parameters on the system performance was analyzed. Results show that at the carbon capture ratio of 90%, the net power generation efficiency, exergy efficiency and CO₂ emissions per kW·h of the present system are 39.97%, 38.94% and 85.27 g/(kW·h), respectively, which are 2.33%, 2.34% higher and 5.27 g/(kW·h) lower than the reference system. The superior performance of the present system comes mainly from the significant reduction in the irreversible losses of its gasification process, which is 62.13% of the reference system. The analysis further indicates that the system net power generation efficiency reaches an optimal 41.3% under the steam-to-carbon ratio of 1.4 and the carbon capture ratio of 80% at the gasification temperature of 1 200 ℃. As the carbon capture ratio increases, the net power generation efficiency and CO₂ emissions per kW·h both decrease, the latter with a minimum of 51.1 g/(kW·h).

An integrated energy system using solid oxide fuel cell (SOFC)/gas turbine (GT) as power generation device and hydrogen-doped natural gas as the fuel was proposed. The mathematical models of various types of energy utilization equipment, such as wind power generation, solar power generation, hydrogen production equipment, SOFC/GT system, energy conversion and storage equipment for electricity, heat, and cooling, carbon capture equipment, etc, were established. The performance and economy of the integrated energy system were studied considering various load balance constraints, equipment operation constraints and aiding in achieving the "dual carbon" targets. Results show that the power generation efficiency of SOFC/GT system increases from 60.36% to 64.79%, and the comprehensive energy utilization rate increases from 87.80% to 90.80% with the increase of fuel hydrogen blending ratio. When the system used renewable energy sources to produce hydrogen, the carbon emissions are the lowest, although carbon trading gains are considered, the high cost of hydrogen production leads to the highest operating costs.

Due to the uneven distribution of combustion temperature field in the operation processes of thermal power plants, issues such as over-temperature, tube explosion and flue gas corridor of the furnace heating surfaces may occur. By evaluating the temperature field distribution of the boiler during operation processes, the combustion adjustment can be made to improve the safety, stability and economy of the boiler operation when the operation status can be examined timely. With the boiler of a 660 MW ultra-supercritical power plant as an example, the combustion optimization adjustment test and simulation were carried out. Temperature of heating surfaces and the wall temperature change at the burner were analyzed, and the wind speed and pulverized coal concentration deviations of powder pipes in the pulverizing system, internal and external secondary air volume and intensity of the burner, the adjustment of the direct current air volume, and the wall air in the furnace were measured. Results show that the factors, such as the combination operation modes of different coal mills and the modes of secondary air distribution have a great impact on the boiler operation. In particular, the wall over-temperature, the burner temperature and reducing atmosphere on the heating surface are influenced, which will affect the boiler economic operation. After adjustment, the wall over-temperature phenomenon of the screen superheater, high temperature superheater and high temperature reheater disappears, there is no burnout of burners, and the amount of NO_x generation is also within a reasonable range.

To explore the application potential of sound-assisted combustion technology in W-shaped flame boilers, the combustion characteristics of a W-shaped flame boiler with real-time load of 315 MW under acoustic excitation were experimentally studied. Twelve and four acoustic excitation devices were staggered in the main combustion area and the burning area of the boiler, respectively, and they were put into operation in a group of three devices in a circular manner. The frequency of the motor driving the acoustic excitation device was 35 Hz, and the corresponding intake pressure was maintained at 0.35-0.47 MPa. In the test, the changes of the NO_x mass concentration at the inlet of the A and B sides of the denitration tower, the SO_x mass concentration at the inlet of the desulfurization unit, and the coal consumption of the unit were recorded through the distributed control system (DCS) of the centralized control room of the power plant. Results showed that, after the acoustic excitation was put into the denitrification tower, the mass concentration of NO_x at the inlet of the A and B sides of the denitration tower is decreased by 6.08% and 5.47%, respectively, the SO_x mass concentration is decreased by 1.24%, and the average coal consumption of the unit is decreased by 1.5 g/(kW·h). In addition, based on the ash sampling analysis of the economizer and air preheater outlet, it is found that the carbon mass fraction of fly ash is decreased by 1.64% and 1.70% respectively, compared with the case without acoustic excitation. Sound-assisted combustion technology can effectively improve the thermal efficiency of W-shaped flame boilers and reduce pollutant emissions.

This paper proposed an integrated system which includes a tower-type solar thermal power system and energy storage system, employing S-CO₂ and quartz as the storage media and a re-compressed S-CO₂ Brayton cycle as the power cycle. Based on the Gensystem platform, mathematical models of the power cycle, solar heat collection system, and S-CO₂ thermocline storage tank were developed to investigate the performance of the heat collection system and the dynamic characteristics of heat storage and release in the S-CO₂ thermocline storage tank. This foundation facilitated an analysis of the integrated system's thermodynamic and economic performance. Results show that after 13 cycles of heat storage and release, the temperature at the outlet of the thermocline storage tank tends to be stable. At the conclusion of heat release, the temperature of the thermal fluid exiting the tank is decreased by 63 K, while at the end of heat storage, the temperature of the cold fluid exiting is increased by 46 K. Compared with a dual storage tank tower solar thermal power system, the average daily power generation efficiency on the summer solstice and winter solstice is enhanced by 1.8% and 1.7%, respectively. The total system investment is reduced by 9.46%, the levelized cost of electricity is reduced by 9.45%, and the investment payback period is shortened by 1.8 years.

As the heart of the gas turbine, the central rod-fastened rotor operates under harsh conditions with frequent incidents, necessitating a rigorous exploration of its strength under complex contact states across multiple scales and loads to ensure the safe functioning of the disc structure. Employing a rough surface contact model and three-dimensional finite element methods, a thermo-mechanical coupling analysis model for the gas turbine disc's Hirth tooth contact interface was developed, incorporating microscale interface dimensions and surface roughness. Results show that the maximum equivalent stress of the end face teeth decreases with the increase of the root fillet radius and the decrease of the pressure angle; the maximum equivalent stress and average contact pressure of the end face teeth decrease with the increase of surface roughness.

Influence of hole configuration including cylindrical, fan-shaped and laidback fan-shaped holes on effusion cooling performance under different pressure drops of cooling air was examined using infrared thermal imaging technology. Results show that due to the vortex impact effect, low local cooling efficiency areas appear on the wall surface, which are independent of the hole type. The change in hole type only affects the cooling effect of the wall surface. Increasing the pressure drop of the cooling air can improve the cooling effect, and the area of the low cooling effect zone also decreases accordingly. The difference between the cooling hole shape and the pressure drop of the cooling air causes the movement of the lowest cooling effectiveness position on the wall. As the velocity of cooling air increases, this point moves upstream. In terms of the uniformity, the minimum effectiveness of cylindrical holes is lower by 14.3% to 27.5% than the area-averaged one. The difference between the minimum cooling efficiency of the fan-shaped hole, the expansion hole and the average level is greater, and the uniformity of the cooling effect is worse. The comprehensive cooling efficiency of the expansion hole is the highest, but the uniformity is the worst.

For the supercritical carbon dioxide (S-CO₂) with heated flow in a horizontal tube, to research the influence of the buoyancy effect on flow and heat transfer characteristics, experiments were conducted on flowing and heating in optical and inner coiled wire tubes under the same condition. Investigations were carried out for the influence of the wall heat flux density and mass velocity on the buoyancy effect, while discussions were given for the influence of the inserted coiled wires on the wall temperature distribution, heat transfer mode, etc. Results show that the temperature stratification caused by the buoyancy effect occurs along the gravity direction during SO₂ horizontal flowing with heating, which leads to the severe wall temperature divergence at the top and bottom, with a maximum wall temperature difference of up to 48 K. The inserted coiled wires in tube can effectively inhibit the temperature stratification caused by the buoyancy effect, while the heat transfer coefficients at the bottom and top are increased by more than 60% and more than 140%, respectively. Based on the validation of experimental results with four heat transfer correlations, it is found that Bishop correlation has the best comprehensive performance.

Aiming to reduce carbon emissions for environmental sustainability, hydrogen-blended combustion has emerged as a pivotal advancement in gas turbine technology. Focusing on the hydrogen-blended natural gas combustion characteristics, comprehensive full-temperature, full-pressure, and full-scale combustion tests with a hydrogen-enriched ratio were conducted on an independently developed DeNO_x burner of F-class heavy-duty gas turbine. The burner's adaptability to hydrogen-blended combustion was analyzed based on performance parameters such as temperature, emissions, humming, and acceleration. Results show that within a hydrogen blending range of 30% to 40%, the NO_x emissions from this burner can be controlled below 30 mg/m³ across the base load range of 55% to 100%. As the hydrogen blending ratio increases, flame transition occurs at a lower load, which is conducive to stable load increases. Furthermore, the outlet temperature of the burner rises, but no flashback occurs.

In order to analyze the influence of inflow distortion on flutter characteristics of gas turbine compressors, an inlet total pressure model with radial distortion was established. Based on the influence coefficient method, the effects of radial inflow total pressure distortion with different phases and distortion intensities on the flow field characteristics and aeroelastic stability of compressors were studied. Results show that the radial inflow total pressure distortion with phase angles of 90° and 180° will increase the minimum value of aerodynamic damping under dangerous conditions, and the aeroelastic stability is improved. The radial inflow total pressure distortion with phase angle of 180° can improve the aeroelastic stability of the compressor at all inter blade phase angles. However, the radial inflow total pressure distortion with phase angles of 0° and 270° will increase the risk of compressor flutter,which should be avoided.

To improve the thermodynamic performance of the heavy duty gas turbine with bleed air, a novel gas turbine system with high effective utilization of bleed air energy was proposed, and the change of thermodynamic performance was researched. Taking the performance data of a traditional typical F-class gas turbine under different ambient temperature conditions as the comparison reference, for the novel gas turbine with high effective bleed air cooling, the changes of performance indicators of the total system were analyzed with different design parameters of cooling system by numerical simulation, while the thermodynamic performances under three operation modes were calculated and compared. Results show that the temperature of bleed air from compressor can be effectively decreased by adopting the novel gas turbine system with high effective utilization of bleed air cooling, and the thermodynamic performance of gas turbine is further improved. Under summer condition, when the inlet air temperature is cooled to 30, 20, and 15 ℃, respectively, the output power is increased by 25.92, 40.49, and 48.22 MW, and the efficiency of gas turbine is improved by 0.78, 1.19, and 1.40 percentage points.

A turbine with high cycle fatigue failure was used as the simulation model, the coupling method of three-dimensional unsteady flow field and solid vibration response analysis was adopted, the simulation of fault point was carried out. According to the different conditions of turbine expansion ratio and turbine reaction force, the law of aerodynamic load distribution and aerodynamic exciting force caused by aerodynamic state change was compared, at the same time, the relative variation trend of blade vibration stress was obtained. Results show that under unchanged intake conditions, the average exciting force, the amplitude of exciting force and the vibration stress of the blade increase obviously with the increase of the expansion ratio of the turbine. While the turbine reaction force increases, the average aerodynamic exciting force of the blade increases obviously, but the amplitude of the exciting force and the vibration stress have a downward trend.

Comprehensive analysis and research were carried out on the performance of large-scale steam ejectors for exhaust steam heat-supply. Based on the inherent characteristics of the steam injector, the performance of the ejector in the exhaust steam heat supply system of a 300 MW class unit under off-design conditions was experimentally studied. The performance curves of the steam ejector under different turbine back pressures, power steam pressures and outlet pressures were obtained. A solution method for full-operation-condition performance parameters of the steam ejector was established. Results show that the performance parameters are in good agreement with the experimental data.

Axial fuel staging (AFS) combustion technology is an advanced low pollution combustion technology for heavy gas engines at present. In order to reveal the effects of H₂/CH₄ fuel species and jet angle on the re-combustion zone flow field and flame structure of axial staged combustion, high-frequency particle image velocimetry (PIV) and OH^*-based self luminescence techniques were used. The effects of 90° and 45° jet angles on the axial staged flow field and the flame structure of different fuels were investigated when the jet equivalence ratio was 0.6 and the momentum flux ratio was 6. Results show that when the jet angle is 90°, there will be an obvious recirculating zone at the root of the jet, and the jet flames have periodic pulsations. When the jet angle is 45°, the shear layer will not produce a significant recirculating zone at the root of the jet, the jet flame burn is more stable, and the chemical residence time of the fuel in the low-speed zone is shorter, which has better adaptability for hydrogen fuel with fast flame propagation speed and easy tempering. The doping of methane fuel with hydrogen increases the propagation speed of the jet flame. With the increase of hydrogen doping ratio, the jet flame gradually changes from a detached flame to a continuous flame, the jet flame branch appears on the windward side, the length of the reaction zone is shortened and smaller, the flame intensity is enhanced, and the flame root moves to the nozzle outlet and finally attaches to the jet nozzle outlet.

The flow heat transfer and cooling characteristics of hydrogen-fired gas turbine were analyzed under coupled action of heat conduction/convection/radiation. A weighted sum of gray gases (WSGG) model was developed to calculate the high ratio of water vapor and carbon dioxide partial pressure. Results show that the increase of water vapor content in the working fluid of hydrogen-fired gas turbine leads to the increase of metal wall temperature. After adding the influence of radiation, the effect of water vapor and carbon dioxide contents on heat transfer is opposite, which is mainly due to the fact that carbon dioxide has a stronger convective heat transfer capacity than water vapor, while water vapor has a stronger radiative capacity than carbon dioxide. Meanwhile, in the hydrogen-fired turbine cooling coupled system with three heat transfer modes of convection-conduction-radiation, the film cooling velocity field is almost unaffected, while the temperature field is deeply affected by coupling effect and radiation. The gas film cooling efficiency under coupled condition defined in this paper can characterize the gas film cooling performance under the condition of hydrogen combustion. Therefore, in the design of hydrogen combustion turbine cooling, the thermal load deterioration caused by hydrogen combustion should be included in the design variables.

In order to improve the efficiency and performance of radial-inflow turbines with organic working medium, one-dimensional aerodynamic design for 400 kW radial-inflow turbine with organic working medium was carried out.Radial-inflow turbine was modeled based on one-dimensional design results,and its performance under designed working conditions was predicted by combining with three-dimensional numerical simulation.Taking isentropic entropy efficiency of radial-inflow turbine as the target,the meridional flow path of impeller was optimized and designed by uniform test method.Results show that the optimized radial-inflow turbine has a more distinct pressure distribution hierarchy than that of the original one,and overall entropy increment, generating friction loss and trailing loss are obviously reduced.Work capacity of the blades increases,and flow inside radial-inflow turbine is improved. Isentropic efficiency of the optimized radial-inflow turbine is increased from 82.33% to 85.92%,and output power is increased by 18.04 kW.

A combined cooling, heating, power and hydrogen poly-generation system with photovoltaic and grid complementary for the chlor-alkali chemical industry was proposed. By establishing the thermodynamic model, the influence of different key parameters on the performance of each unit of the system was explored, and the operation strategy of the system was analyzed. Results show that compared with the conventional chlor-alkali system, the energy utilization efficiency of the poly-generation system is improved by 14.65%, annual carbon emission is reduced by 31%, and daily power purchase costs are reduced by 25.4%-51.1%.

This study focuses on the squealer tip film cooling design of turbine blades, presenting three layouts: two with full ribs, one with a full rib and a half-rib on the pressure side, and one with a half-rib on the suction side. Using numerical simulations through three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations and a standard k-ω turbulence model,the heat transfer and cooling performance of grooved blade tips with two full rib layouts were studied under four different blowing ratios.The aerodynamic and heat transfer performance, as well as film cooling effectiveness of blade squealer tip with different rib layouts and typical squealer tip without rib layout were compared and analyzed at blow ratio 1.0 condition. Results show that the distribution of heat transfer coefficient at the blade tip predicted by numerical methods is in good agreement with the experimental measurement results, which verifies the reliability of the numerical method; at a blowing ratio of 1.0, the squealer tip with full ribs exhibits the highest average film cooling effectiveness, surpassing the typical groove design by 2.2% in effectiveness. The layout with half ribs on the pressure side shows the lowest average heat transfer coefficient and total pressure loss. Rib configurations markedly alters the flow structure over the leaf top, thereby affecting its aerothermal performance and film cooling effectiveness, with the full rib layout displaying optimal overall aerothermal performance and cooling effectiveness.

In order to investigate the impact of key parameters on the thermodynamic performance of both the overall and critical components of a hydrogen-blended heavy-duty gas turbine, a thermodynamic performance calculation model was established,and the definitions and settings of the key parameters in the moldel were explained. By examining different hydrogen blending ratios, turbine inlet temperatures, compressor pressure ratios, and cooling air volumes, the study assessed their influences on the power output and thermal efficiency of gas turbine. Additionally, changes in turbine aerodynamic parameters under different hydrogen blending ratios were analyzed, and the mechanisms behind the impact of hydrogen blending on gas turbine performance were further revealed. The results show that the mixing ratio of hydrogen, turbine inlet temperature, pressure ratio and cooling air quantity are the key parameters that affect the performance of heavy duty hydrogen blended gas turbine; and the changes in aerodynamic parameters of the turbine such as turbine flow angle and outlet Mach number caused by the hydrogen blending ratio changing will affect the aerodynamic performance of the turbine and the thermodynamic performance of the gas turbine.

Experimental studies were conducted on two types of micro-mixing diffusion combustors, one with a swirl number of 0.62 and another one without swirl, under the equivalence ratio from 0.3 to 0.5. The influences of swirl on the flow field distribution, flame structure, NO_x concentration, and combustion instability of micro-mixing diffusion combustion were investigated experimentally. The methods of OH^* chemiluminescence and particle image velocimetry (PIV) were used to capture flames and flow structures. Results show that adding swirl can reduce the flame height by 44% and shorten the residence time by changing the flow field structure, ultimately achieving a 63.4% reduction in NO_x emissions. Without swirl, the main driving factor of micro-mixed diffusion flame pulsation is the formation of radial expansion zone under high equivalent ratios, while swirling flow can inhibit the formation of radial expansion zone, so as to achieve the effect of suppressing combustion oscillation in a wide load range.

Based on Bezier curve, a parameterized configuration method for outlet shape of film cooling hole was proposed. Outlet shape of film cooling hole could be changed by adjusting control points of Bezier curve. Latin hypercube sampling (LHS) and numerical simulation methods were used to obtain a large number of film cooling effects with different outlet shape of film cooling hole. Radial basis function neural network (RBF-NN) prediction model and genetic algorithm (GA) were used to optimize outlet shape of film cooling hole. Results show that the optimized cooling holes can effectively inhibit strength and size of counter-rotating vortex pair (CVP), and reduce the mixing loss between cooling flow and hot main stream; at the same time, the optimized outlet shape of film cooling hole has an expansive channel, which weakens upward momentum of cooling flow at the outlet of film cooling hole, effectively inhibits penetration of cooling flow to hot main stream, and enhances film cooling efficiency. Under the blowing ratio (M) of 0.91, the film cooling efficiency of the optimized film cooling hole is improved by 40.48% and 17.82%, respectively, compared to that of circular hole and fan-shaped hole.

Existing methods for evaluating yaw error of wind turbine often rely on lidar or long-term (more than three months) operating data. A yaw error algorithm based on actual power curve threshold screening was proposed for calculation of short-term operating data yaw error before the first maintenance of new units. Firstly, the Bin method was used to solve the actual power curve of unit, and the threshold method of the actual power curve was used to eliminate data that may reduce calculation accuracy with no need for nacelle transfer function (NTF). Then, the selected dataset was divided into wind speed compartments, and interval mean method was used to solve the representative yaw error of each wind compartment. Finally, wind speed weighting method was used to solve the yaw error. Through practical application in an onshore wind farm in Jiangsu, it shows that the proposed algorithm can obtain effective yaw error calculation results for both short-term and long-term operating data.

To solve the problem of ANSYS-Fluent software being unable to provide both high-precision and high-efficiency radiation spectrum models, secondary development was carried out for the full-spectrum correlated-k distribution (FSCK) model based on look-up table method and machine learning method, and the model was embeded into Fluent and coupled with built-in radiative transfer equation (RTE) solvers for radiation heat transfer calculation for mintures of common combustion gases and soots. Radiation heat transfer results of one-dimensional slabs and two group of flames were calculated by the model, and using the line by line (LBL) model as a benchmark, which were compared with the results calculated by gray gas weighted sum (WSGG) model in Fluent. Results show that the FSCK model yields more accurate solutions than the built-in WSGG model in Fluent, regardless of the presence of soot.

The flow field near the endwall of gas turbine cascade presents extremely complicated three-dimensional characteristics, and the endwall cooling design needs to consider not only the effects of the strong secondary flow of the endwall on the cooling performance, but also the effects of the cooling layout on the flow and heat transfer characteristics of the proximal endwall. In view of the cooling demand for the gas turbine cascade endwall, a combination of numerical simulation and experimental test were used to systematically investigate the effects of discrete air film holes, leakage flow and endwall modification on the endwall surface film cooling, heat transfer, flow and cascade aerodynamic characteristics under different mass flow ratios. The results show that, the film cooling effectiveness of the endwall can be effectively improved by the appropriate injection angle and layout of the film holes, the geometric structure of the leakage flow cooling unit and the addition of micro-scaled ribs on the endwall surface. The leakage flow from upstream slot and rim seal can provide cooling protection for the upstream and the area near the suction surface of the upper half of the endwall, while the leakage flow from mid-passage gap will protect the rear half endwall near suction side well. The arrangement of fan-shaped air film holes and the curved assembly gap can not only improve the effectiveness of film cooling, but also effectively control the aerodynamic losses.

Taking the F-class gas turbine compressor as the research object, the performance degradation mechanism of multi-stage axial compressor at different states of corrosion/ware was studied by three-dimensional numerical simulation, considering the changes in blade tip clearance caused by corrosion and wear during actual operation of gas turbine. The influence of tip clearance on the performance of multi-stage axial compressor was analyzed. Results show that the increase of tip clearance causes the characteristic curves of the compressor to move towards the direction of mass flow reduction as a whole, resulting in certain degree of decline of mass flow, efficiency and pressure ratio. With the increase of tip clearance, the compressor maximum efficiency decreases gradually, and the surge margin decreases obviously. The increase of tip clearance also results in intensified flow separation inside the compressor, and the change of tip clearance of rotors has more serious impact on flow separation inside the compressor. The flow separation near the trailing edge of the suction surface of stators leads to the formation of a low Mach number region, and the loss near the stator root increases obviously due to the countercurrent low-speed vortices, resulting in the decline of compressor performance.

From the perspective of gas turbine blade cooling design, the study and application progresses of data-driven methods of domestic and foreign researchers in recent years was summarized. Three types of data-driven methods including mathematical statistics, machine learing and deep learning were introduced. The advantages of data-driven methods over experimental and numerical simulations were expounded. And the application of data-driven methods was emphatically summarized, mainly including predicition and uncertainty quantification of turbine blade cooling characteristics, improvement of turbulence models in numerical simulation, and data fusion of existing data and knowledge. Based on the current research hotspots and development tendency, further studies focus on data-driven methods in gas turbine blade cooling design were proposed, including exploring the potential of data fusion approches, improving generalization ability, reducing data cost, studying data processing methods, comparing the advantages and disadvantages of different data-driven methods, and developing data-driven approaches for complex cooling designs.

To address the response issues caused by time lag and load fluctuations in NO_<i>x emission control of SCR denitrification system, reinforcement learning was employed to adjust the proportional-integral-derivative (PID) parameters. The loss function of Critic network was redesigned according to the deep deterministic policy gradient (DDPG) algorithm, and a delay queue was introduced to simulate system latency. The proposed control strategy has been applied to a 660 MW ultra-supercritical coal-fired power unit in China. Results show that the reinforcement learning control method is superior to traditional PID control in terms of adjustment time, overshoot, and stability. The proposed strategy overcomes the time lag and load fluctuations that traditional PID control cannot resolve, demonstrating the significant theoretical and practical values.

Under the "dual carbon" goal of China, to further reduce the carbon emissions of the integrated energy system (IES) and enhance the accommodation capacity of renewable energy, a low-carbon economic operation optimization strategy for IES was proposed. Firstly, a stair-like carbon trading mechanism was introduced to constrain the carbon emissions of IES; Then the coupled power to gas (P2G) and carbon capture system (CCS) model was established, and the two-stage operation of P2G was refined; Next, the Karina cycle and electric boiler were introduced to operate jointly in traditional combined heat and power (CHP) units, and a CHP model with flexible heating and power outputs was constructed; Finally, with the optimization goal of minimizing the sum of system operation and maintenance costs, carbon trading costs, energy purchase costs, and wind and solar abandonment costs, an IES low-carbon economy scheduling model was constructed, and different operating scenarios were set for comparative analysis. Results show that the carbon emissions of IES are reduced by 38.45%, and the total operating cost is reduced by 10.37%, verifying the low-carbon and economic performance of the established model.

The axial staged combustion chamber of the self-developed F-class gas turbine was studied under full temperature and full pressure condition. In order to explore the combustion performance of the combustion chamber under the working conditions of the design point, such as pressure loss, outlet temperature distribution, wall temperature, pollutant discharge, combustion efficiency and thermoacoustic stability,etc. Results show that, the total pressure loss coefficient of the combustion chamber is 5.4% at the design point. The outlet temperature distribution factor and radial temperature distribution factor are 0.06 and 0.03, respectively. And the wall temperature of the flame barrel in the combustion chamber is below 850 ℃. The mole fraction of NO_x is maintained 1.9×10^-5, while the emissions of CO and unburned hydrocarbon(UHC) are basically zero. The combustion efficiency is maintained above 99.99%. The amplitude of dynamic pressure spectrum is below 3 kPa, which indicates the thermoacoustic state of the combustor is stable.

Taking the combustor liner of F-class gas turbine as the research object, analysis was carried out on the internal flow field, temperature field and stress field of the combustor liner under rating operation conditions based on fluid-thermal-solid coupling method, considering the effect of thermal barrier coatings and cooling structures on the aerodynamic heat transfer of the combustor liner. The results of numerical analysis were compared with the actual damage situation of the combustor liner. Results show that the high stress areas are basically consistent with the actual damaged regions of the combustor liner, thus the fluid-thermal-solid coupling method can be used to predict the damage situation of the combustor liner. The ceramic layers of the thermal barrier coatings at different locations have similar insulation effect. Both the substrate and the ceramic layers of the thermal barrier coatings in the vicinity of the cooling structures are areas of high stress.