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.

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 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.

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.

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.

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.

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.

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.

Aiming to the performance analysis of boiler with supercritical carbon dioxide (S-CO₂) cycle, the boiler performance evaluation index system is built by taking the gas-fired boiler used in the 5 MW S-CO₂ Brayton cycle pilot unit at Xi'an Thermal Power Research Institute Co., Ltd. as the research object. The core performance indexes of S-CO₂ boiler include the fuel efficiency of boiler, the ratio of heat absorption over the input heat for each heat exchanger, the performance of air preheater, the pressure drop of working fluid system, the NO_x emission concentration, and others. The fuel consumption and excess air coefficient are calculated via the measurement of oxygen concentration. Meanwhile, the calculation method of heat loss due to exhaust gas is improved. The ratio of heat absorption over the input heat for each heat exchanger is introduced, which shows the contribution of each heat exchanger on heat absorption process. Finally, the calculation process is integrated becoming to an executable program, and it is applied in the running and monitoring procedures. An operating case showed that, for the research object, the actual condition is basically the same as that of the design parameters. The finally calculated boiler fuel efficiency is 92.05% without correction and 93.79% with correction, the later is similar as the designed value (93.53%).