In order to use the market mechanism to reduce carbon dioxide emission and promote green low-carbon transition, countries around the world have successively built carbon emission trading markets. Carbon dioxide emission monitoring technology is the main technical method to achieve accurate carbon emission measurement. It is an important technical support to assist the carbon emission accounting system. This paper focuses on the analysis of the current situation of carbon dioxide emission monitoring and accounting in the power generation industry, and introduces the carbon dioxide emission monitoring methods in the power generation industry in detail, including emission factor based method, online monitoring method, carbon balance method, soft sensing method, and satellite monitoring method. In view of these monitoring methods, this paper systematically reviews the researches of carbon dioxide emission monitoring methods in the world, expounds the advantages and disadvantages of the monitoring methods, compares the methods from accuracy, timeliness, reliability and monitoring cost, and provides reliable technical solutions for carbon dioxide emission monitoring in the power generation industry. Finally, we make an outlook on future research directions and practical applications.

Chemical absorption method is an important way to apply and treat CO₂ from coal-fired power plants on a large scale, however, the traditional chemical absorption method with monoethanolamine as absorbent has been limited in its wide application because of the high energy consumption. In this paper, the research progress on the improvement of CO₂ capture process is reviewed with the new CO₂ capture solvents, the improvement of absorption process including intermediate cooling of absorber and solvent recirculation, Flash compression and regeneration process of steam/pentane direct purging are summarized, it was also pointed out that pilot-scale verification of new solvents based on the actual composition of flue gas, and the study of capture solvent degradation properties and volatile organic compound treatment processes were the research and development directions of carbon capture research, it points the way for future research on industrial carbon capture.

The proposal of the "dual carbon" has brought profound changes to the development of China's energy and power industry. As the leading enterprises in China's power industry, the five major power generation groups should play a demonstration and leading role, analyze and evaluate their low-carbon transformation achievements have important significance for the power generation industry to achieve the "dual carbon" goal as scheduled. This article uses the entropy weight TOPSIS method to conduct empirical research and analysis on the indicator data of the five major power generation groups in China from 2017 to 2021. The empirical results show that from a vertical dimension, it is found that the low-carbon transformation of the five power generation groups has achieved good results in 2017 to 2021, and the low-carbon transformation performance of each power generation group has shown an increasing trend year by year. This indicates the implementation of policies related to structural adjustment, emission reduction, and re transformation of the five power generation groups, achieved positive and significant results; from a horizontal perspective, the rankings of the five major power generation groups have been constantly changing from 2017 to 2021, indicating that each power generation group has made varying degrees of progress in low-carbon transformation.

In order to study the feasibility and economic benefits of implementing carbon capture, utilization and storage (CCUS) technology in coal-fired power plants, based on the thermal power installation planning and generation data provided by a northwestern province, three different CCUS transformation schemes in 2023, 2025 and 2030 were proposed, and their economic analysis was conducted. It is found that the first plan needs investment of 1 220.293 billion yuan, which translates into an increase of about 0.076 3 yuan /(kW·h); the second plan needs investment of 1 123.19 billion yuan, which translates into an increase of about 0.076 9 yuan /(kW·h); the third plan needs investment of 860.12 billion yuan, which translates into an increase of about 0.069 0 yuan /(kW·h). Aiming at the high cost of CCUS transformation scheme, a technical route combining CCUS and methane dry reforming was proposed, and the captured CO₂ was used to produce syngas. It was found that the expenditure and income of 1 t CO₂ due to the consumption of natural gas to produce syngas were 1 520.7 yuan and 3 247.2 yuan respectively. Comprehensive carbon capture system analysis options two and three can achieve zero-cost decarbonization.

Ammonia is a kind of zero-carbon fuel with mature technology and low storage and transportation cost. Partial replacement of coal with ammonia can become an effective way to reduce carbon at the front end of coal-fired units under the dual carbon target. Ammonia fuel is studied as an alternative fuel. The fuel characteristics of ammonia and its blended fuel with typical bituminous coal are studied by using one-dimensional flame furnace and ignition furnace. The ignition performance changes of ammonia/coal blended fuel, the enhanced combustion and pollutant control technology of different proportions of ammonia blended fuel are studied and analyzed in detail. It is found that the pre-blended combustion of ammonia/coal is not conducive to NO_x control. Through fuel grading, combustion excess air coefficient or oxygen control, and air staged combustion, lower NO_x generation concentration and better combustion effect can be achieved during ammonia blending. The operation control suggestions of 25%ammonia mixed with typical bituminous coal are obtained.

The power industry is the core of the energy system as well as a major carbon emitter. The zero-carbon development of it is the key to the process of carbon neutralization in China. From the perspective of carbon emission, energy resource endowment, industry status, existing problems and development trend, the general situation, low-carbon development path and effect of the electric power industry in the United States, Germany, France and Britain in the European Union was analyzed. Several enlightenments combined with the current situation of the electric power industry in China were summarized, hoping to provide reference for the low carbon development of Chinese electric power industry.

The combustion of biomass will not increase carbon dioxide emissions, and the development of biomass coal coupled power generation technology is a feasible way to accelerate the transformation and upgrading of electricity. The compressed biomass and coal powder are ground in different coal mills without mixing, and are fed into the furnace by different burners. This method does not require additional biomass treatment equipment or setting up a biomass fuel treatment workshop, which can greatly save investment and factory space. The key limiting technical factor is whether the pulverizer of the power plant can effectively grind biomass Pellet fuel, and how to evaluate the adaptability of the existing pulverizer to the new coupling fuel. To this end, a medium speed coal mill experimental platform was built to analyze the adaptability of the medium speed coal mill in grinding biomass particles. The results show that the grinding output of the medium speed coal mill decreases when grinding wood chip biomass particles, and the effective output correction coefficient is 0.65~0.70; When the ZGM medium speed coal mill grinds sawdust particles, the loading force characteristics and separator characteristics both vary significantly at the particle size boundary of 0.2 mm. Therefore, the screening fineness R₂₀₀ and R₅₀₀ can be considered as the measurement standards for the uniformity of biomass particle materials ground by the coal mill; Compared with pulverized coal, the increase of loading force of milled biomass particles or the increase of rotating speed of the current separator has a large difference in the influence of fineness distribution, which needs further in-depth research.

The carbon content of fly ash in boilers is one of the important indicators of combustion efficiency. This study employs machine learning models to accurately predict the carbon content of fly ash. Firstly, random forest is employed to adjust the frequency of fly ash carbon content data to once per minute, aligning it with the input features to address the issue of imbalanced data collection frequency. Then, a recursive feature elimination method based on random forest is used to extract nine important features out of the original 30 features, reducing feature correlation and improving model accuracy. Subsequently, six machine learning models (linear regression, decision tree, K-nearest neighbors (KNN), random forest, Catboost and XGBoost) are compared for prediction. The results indicate that decision tree, KNN, random forest and XGBoost models perform well, MSE of which on the test are 0.010, 0.009, 0.006 and 0.006, respectively, while linear regression exhibits the poorest performance. The prediction models remain robust under low, medium, and high boiler loads.

The intelligent retrofit of coal-fired power generation units is an inevitable choice for improving energy efficiency and promoting green industrial transformation. Based on practical requirements and engineering perspectives, this article designs the overall framework and key technologies for the intelligent retrofitting of wet flue gas desulfurization systems. First, the structural components of the intelligent control system (ICS) network framework are discussed. Next, based on the ICS framework, an optimized control strategy combining information-physical fusion models and advanced control algorithms is designed, as well as an optimized control strategy for the absorption tower pH value based on the direct energy balance (DEB) approach. Simultaneously, the information-physical fusion optimization results guide the analysis of the intelligent evaluation system. Using data twin technology and mechanism models, intelligent early warning and fault diagnosis for the system are achieved. By analyzing typical faults, an expert system is established, combined with data-driven techniques for real-time fault tracking. Finally, the article points out that a visualization-based human-machine interaction system is used for real-time display of desulfurization system indicators, constructing an integrated desulfurization system that combines ICS, digital twins, machine learning and visualization. This provides a basis for realizing a self-optimizing, self-learning, self-recovering, self-organizing and self-adaptive intelligent desulfurization system.

Conventional industrial steam turbines are usually equipped with quick-closing inlet valves to realize emergency shutdown of the turbine. In this paper, a negative pressure inlet condensing steam turbine was studied has low inlet parameters, large inlet steam volume flow and small pressure difference between inlet and exhaust steam ends. In order to reduce the intake pressure loss, the quick-closing inlet valves are not employed, but a redundant large-diameter rapid vacuum breaker valve is used at the exhaust end of the turbine. When the turbine needs emergency shutdown, open the quick vacuum breaker valve, so that the atmosphere quickly enters the exhaust end of the turbine, the pressure of the exhaust end of the turbine rapidly rises, In this paper, the steam turbine whose inlet and exhaust steam pressure difference is 40 kPa is studied, and the pressure difference between the inlet end and the exhaust end of the turbine could reach 0 within 4 seconds, so that the turbine is closed, and the purpose of emergency shutdown of the turbine is achieved.

Rapid and accurate measurement of the calorific value of incoming coal is the essential to provide guidance for the economic and safe operation of power plants. However, coal has complex components, and the calorific value is correlated with elemental composition and molecular structure, it is difficult to measure coal calorific value quickly and accurately by a single analytical technique. Based on laser-induced breakdown spectroscopy (LIBS) and near-infrared reflectance spectroscopy (NIRS), a method is proposed to detect the calorific value of incoming coal by combining two techniques. The LIBS and NIRS spectral signals of the coal on the conveyor belt are collected simultaneously. Fusion of two spectral information after data pre-processing, coupled with partial least squares (PLS) modeling method to quantify coal calorific value. This method is used in a coal sample measurement system built by lab, it is reached that the coefficient of determination of the calibration set was 0.98, and the root mean square error of the prediction set was 0.37 MJ/kg, with an average absolute error of 0.26 MJ/kg and an average relative error of 1.09%. The results show that the proposed method of simultaneous acquisition of LIBS and NIRS signals can measure coal calorific value rapidly and accurately.

The alkali metals released during combustion of high alkali coals can easily lead to fouling and slagging of the heated surfaces of the furnace, affecting the safety of boiler operation, and it is significant to carry out the research of the slagging trend prediction. In this paper, a system for dynamic prediction of slagging trends in the furnace was developed by combining the slagging trend discrimination method based on ash composition analysis with flame emission spectroscopy. Firstly, a flame emission spectroscopy system was installed on the boiler to measure the gas phase alkali metal concentration in the furnace, and then a slagging trends test was carried out in the furnace exit area to obtain the deposition trend of the ash samples. Finally, a dynamic predictive system for predicting slagging in the furnace was developed and applied to the boiler by combining the slagging discriminating trends based on ash composition analysis of different coal samples and online monitoring of gas-phase Na concentrations, which can reflect the monitoring results of each parameter under the current combustion conditions in real-time, indicate the slagging trend in the current combustion state, thus enabling combustion adjustment instructions to prevent severe slagging.

The overheating of boiler heating surface seriously affects the safe operation of the power plant. It is of great significance for the safety of boiler to predict the tube temperature of heating surface and to take appropriate preventative measures. A data driven-based model for tube temperature prediction is proposed in this study. Firstly, the key variables affecting the tube temperature are selected by grey correlation analysis that affect the wall temperature of the heating surface, and a wall temperature prediction model based on long short term memory (LSTM) neural network is constructed. Then, the correlation feature coefficients under similar historical operating conditions are defined, and the predicted wall temperature obtained by the LSTM neural network is corrected to improve the model's prediction accuracy. Finally, an on-duty supercritical boiler with 600 MW capacity is taken as the case study. Results showed that the relative error of the proposed prediction model is within (−2.5%, 2.5%). The average relative error is 0.40%, and the average tube temperature prediction error is 2.24 ℃. It indicates that the proposed model is helpful for the tube temperature prediction of the boiler under complex operating conditions.

Building a new power system focusing on new energy resources puts forward higher requirements for deep peak shaving of coal power unit. Through the requirement analysis of power grid and the comparison of various energy storage technologies, taking the system characteristics analysis of coal power unit as the starting point, a system and a operation mode were given which were based on molten salt thermal storage to assist deep peak shaving of coal power unit. Through theoretical analysis, the calculation methods of the main parameters of subsystems including the heating, heat storage and heat exchange of the molten salt system have been put forward.Taking a 660 MW coal-fired unit as an example, based on the analysis of the thermal boundary and peak shaving demand, the power and connection mode of the electric heating module of the molten salt system are calculated using the calculation method proposed in this article. The types of molten salt and the inlet and outlet parameters of the heat exchange system are selected. The capacity, salt consumption and tank volume of molten salt heat storage are determined. All the results provide reliable data support for accurate accounting of project investment and land occupation. This system and calculation method can provide reference for the preliminary design of similar projects.

The analysis of heat and mass transfer process has important guiding significance for the performance improvement of heat and mass transfer equipment. Through the analysis of the thermal resistance in the boundary layer, the author explores the development of the convective thermal resistance and thermal conduction thermal resistance in the laminar flow of the pipeline in the boundary layer, and establishes a mechanism model (R-P model) that conforms to the macroscopic characterization. The thermal resistance distribution law under the condition of Re and Pr, explored the internal mechanism of laminar flow enhanced heat transfer in the tube, and guided the optimal design of the flow-around structure. The results show that the heat conduction is absolutely dominant in the inlet stage, and the proportion of convection gradually increases after the full development. The mechanism of Re and Pr affecting heat transfer is different. When Re increases, the heat transfer must be strengthened. When Pr increases, it only increases the proportion of convection, and in the range of (Pr<1.8), thermal resistance always plays a major role. At the same time, it was found that adding a turbulent flow structure to the laminar flow in the pipeline would reduce the heat transfer effect.

Condensate downcomer vibration is a common phenomenon in the direct air cooling system, which endangers the safe operation of the air cooling system when the vibration is serious. The pipe vibration model is established based on the fluid solid coupling method. The two-phase flow characteristics of the condensate pipe are analyzed using the theory of flow induced vibration and fluid cavitation. The model analytical calculation and numerical simulation are carried out for the condensate pipe of a 660 MW ultra supercritical unit. The results show that saturated or nearly saturated condensate flows from the air cooling platform along the condensate downcomer to the hot well of the steam exhaust device by gravity flow. When the potential energy of water is released, two-phase flow excitation and cavitation phenomena occur. Based on this analysis, the causes of condensate vibration and cavitation noise are found, By using multi-stage Venturi tubes and porous orifice plates in the condensation water pipeline of the power plant to eliminate the condensate potential energy, avoid excessive pipeline vibration and noise, and eliminate the hidden danger of pipeline vibration.

Under the background of carbon peak and carbon neutralization, the importance of thermal power generation in northwest China has been further increased. Due to the high proportion of high alkali coal in this area, serious slagging and contamination come out easily in the process of burning high alkali coal in boiler. It's of vital importance to solve the problem of safe burning of high alkali coal ensuring the safety of electric power in China. The present situation of high-alkali coal combustion technology at home and abroad is introduced in this paper. With more than ten years' research, the high-alkali coal combustion technology in China has been improved remarkably, and the related achievements have been popularized and applied in the electric power industry. The blending ratio of high alkali coal in boiler has been increased from less than 60% to more than 90%, though the full burning of high alkali coal has not been realized yet. This paper introduces different technical routes to realize full burning of high alkali coal and analyzes the equipment parameters and operation of typical boilers burning high alkali coal. Generally speaking, pulverized coal boiler, fluidized bed boiler and liquid slag boiler have their own advantages and disadvantages in the adaptability to high alkali coal, with technical bottlenecks to be further studied and broken through. In order to ultimately solve the high alkali coal combustion problem, more new technologies need to be introduced.

Large proportion burning high-alkali coal will cause serious contamination to the heating surface of the boiler, and threat the device security and stable production of the power plant. The article compared flue gas temperature changes of three types of boilers burning Xinjiang Naomaohu high-alkali coal, XRD phase analysis and chemical composition analysis of ash slag was also performed. Analysis results indicate the composition of the ash block developed by short-term bonding is close to that of coal ash, and the texture is loose, and the heating surfaces can be kept clean by soot blowing optimization. The shell-like slag formed by long-term contamination is rich in SO₃ and Na₂O, the degree of sintering is high, and the texture is hard, controlling the flue gas temperature of the heating surface inlet can effectively reduce the fouling and slagging of the tube panel. The flue gas temperature at the convection heating surface inlet with tube panel gaps of about 50 mm should be controlled below 800 ℃, when the gaps are above 200 mm, the flue gas temperature should be controlled below 1 000 ℃. The results of the research can be used as a reference for the same type of boiler burning high-alkali coal.

In order to solve the safety and economic issues of mixed combustion of multiple fuels such as gas, lignite, and coal slurry in power plant boilers, an evaluation method for the blending of multiple fuels was proposed. Firstly the constraints on the moisture, volatile matter, calorific value, and sulfur content of the fuel entering the furnace under different loads are established, based on the fuel characteristics and various requirements for safe operation of the unit, and then the minimum comprehensive power supply cost and the optimal blending scheme for multiple fuels under different loads are determined through blending experiments. The experiments were conducted on a 300 MW power plant boiler, and the results showed that, on the premise of meeting the constraints of the incoming fuel, the fuel cost for power plants can be decreased by increasing the proportion of economic coal blending based on the principle of minimizing comprehensive power supply costs. This study will provide important reference for the study of multi fuel blending in power plant boilers.

Zhundong has large coal reserves and low mining costs, making it the most economical fuel in the Xinjiang Zhundong region. However, Zhundong coal has strong slagging and fouling properties, which seriously restricts the safe and stable operation of boilers. Boilers in the Zhundong region usually require burning at least 20% low alkali coal, the low reserves and high prices of low alkali coal seriously constrain the cost reduction of power plants. In order to promote cost reduction, an experimental study on burning high ratio of Zhundong high alkali coal was conducted on the 350 MW unit boiler of Wucaiwan Power Plant. A collaborative optimization strategy was adopted to prevent and control slag and contamination on the heating surface of the boiler. This included adding kaolin to coal to regulate the composition of coal ash, and deeply optimizing the operating parameters of the pulverization system, combustion system, and soot blowing system. The test results show that the collaborative optimization strategy has solved the long-standing problems of large-scale slag flow on the water-cooled wall, clogging of the burner nozzle, and severe fouling of the convective heating surface of this type of boiler. The safety and load capacity of the boiler operation have been greatly improved, and the coal structure can be lastingly maintained as 92.5% Zhundong high alkali coal and 7.5% kaolin, with significant safety and economic benefits.

In order to solve the problems of high pollutant emission mass concentration, low energy utilization rate and high initial investment cost of conventional waste disposal power station, combined with the green transformation development needs of coal-fired power station. This paper proposes the technical ideas of coal-fired boiler station coupled with waste. A 30 t/d coal-fired boiler station coupled waste was built to analyze and study the impact of system operation on the efficiency of coal-fired power station, pollutant emissions and energy efficiency of waste disposal. And this paper uses three coupling methods of hot air, flue gas and steam water to achieve efficient and clean disposal waste on large coal-fired power station. The results show the three coupling methods are completely feasible to achieve efficient and clean disposal waste. The coupling of hot air can improve the effect of disposal waste and reduce the carbon content of fly ash and slag; the coupling of flue gas can ensure conventional pollutants such as SO₂, NO_x and dust reach the emission level of coal-fired power station without increasing the emission of dioxins. The coupling of steam water can improve the energy efficiency of disposal waste. This technology provides new technical ideas for the disposal of organic solid waste and has a broad application prospect.

In order to explore the way of high efficiency and low nitrogen combustion in oxy-fuel combustion, the experimental study on oxy-fuel staged combustion characteristics of Shenfu bituminous coal and Yunnan inferior bituminous coal was carried out on the down-draft furnace of Dongfang Boiler Test Center, and the burnout characteristics and nitrogen oxide emission characteristics of two kinds of coal under oxy-fuel staged combustion conditions were explored. The experimental results show that under the condition of oxy-fuel combustion, the combustion efficiency of Shenfu bituminous coal can reach more than 99%, and the NO_x emission concentration in flue gas can be controlled within 19.10 mg/MJ by using over-fire air staged combustion and reasonable control of oxygen staged feeding. The combustion efficiency of Yunnan inferior bituminous coal is slightly lower due to the delay of ignition and the long enough residence time required for burnout. However, the combustion efficiency can reach more than 90 % with reasonable oxygen classification, and the NO_x emission concentration in flue gas can be controlled within 16.83 mg/MJ. The effect of furnace temperature of oxy-fuel combustion on the cumulative formation and release curve of NO_x is consistent with that of air combustion. The higher the furnace temperature, the faster the heating rate of pulverized coal particles. The higher combustion efficiency and lower NO_x emission concentration can be found by adopting oxy-fuel staged combustion and reasonably controlling the timing and position of oxygen staged injection, so as to achieve high efficiency and low NO_x emission of oxy-fuel combustion.

The failure of boiler tubes in thermal power units will cause non shutdown of units and greater economic losses. Deposits in boiler tubes are an important reason for their failure, and reducing deposits in boiler tubes is of great significance to the safe and stable operation of units. It is found that the formation of deposits is related to many factors, such as overheating of furnace tubes, high heat load, poor water vapor quality, water vapor phase transition, working medium disturbance and pipe surface defects. Combined with the flexibility of units, deep peak shaving operation, environmental protection reform and other conditions, the formation mechanism and influencing factors of various types of deposits are analyzed with actual accident case pictures. The effects of overheating, salt concentration and corrosion under scale caused by deposits in furnace tubes are further discussed. The countermeasures for feedwater quality, boiler shutdown protection, unit startup steam purification, unit peak shaving, boiler tube replacement, boiler transformation and maintenance are proposed, which can effectively reduce the generation of boiler heating surface deposits and reduce the risk of boiler tube failure.

To effectively alleviate the high-temperature corrosion of the water-cooled walls on both sides of the opposed wall combustion of a 660 MW unit's boiler and the erosion caused by coal particle impingement, a solution was proposed to deflect the swirl burners near the side walls by 3.5° towards the center of the furnace. This solution was based on an understanding of the causes and mechanisms of high-temperature corrosion and considering the on-site equipment conditions. Numerical simulations were conducted to analyze the combustion in the boiler before and after the burner deflection. A comparative analysis was performed on the changes in temperature distribution, velocity field, concentration field, and particle trajectories resulting from the burner angle deflection. The proposed solution was also implemented in practical engineering. The results of the numerical simulations and engineering application demonstrated that after deflecting the burner angles, the airflow inside the furnace concentrated towards the center, resulting in a reduction of coal particle impingement near the side walls and mitigating erosion. Additionally, the temperature near the side walls decreased, leading to a decrease in reducing atmosphere and a reduced risk of high-temperature corrosion. The combustion efficiency of the boiler remained unaffected. The findings of this study can serve as a reference for preventing and managing high-temperature corrosion and water-cooled wall erosion in boilers of similar types.