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.

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 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.

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.

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.

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.

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.

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.

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 combination of supercritical carbon dioxide Brayton cycle and lead cooled fast reactor is considered as one of the most ideal power cycles. The system transfers heat through the intermediate heat exchanger, and its performance affects the efficient and safe operation of the whole power generation system. Due to the significant differences in physical properties and heat mass transport properties between supercritical carbon dioxide and liquid lead bismuth eutectic, the symmetrical structure cannot match the heat transfer requirements of the working fluids on both sides. In this study, an asymmetric compact coupled heat exchanger was constructed, and the coupled heat transfer characteristics of supercritical carbon dioxide and liquid lead bismuth eutectic were studied by numerical simulation. Increasing the inlet velocity of the cold side fluid will significantly enhance the heat transfer; When the inlet velocity of LBE at the hot side is increased, the total heat transfer coefficient first decreases and then increases; When the inlet temperature of the cold and hot fluid of the heat exchanger is increased, the heat transfer coefficient of the heat exchanger first decreases and then increases, and there is an optimal value; Due to the high proportion of thermal resistance in the cold side, the similarities and differences of heat transfer characteristics of cold side supercritical carbon dioxide under buoyancy and thermal acceleration under different operating parameters are compared; It is found that in the quasi critical region, the strong buoyancy will greatly enhance the cold side heat transfer, while the acceleration effect will inhibit the heat transfer.