Measuring the investment value and investment timing accurately is crucial for coal-fired power plants' carbon capture utilization and storage (CCUS) investment. Different from the existing studies on the CCUS decision making only considering the integration mode, this study establishes the decision-making model of the CCUS investment of coal-fired power plants under the integration mode and joint venture mode from the perspective of coal-fired power plants. The decision-making model is established based on the theory of real options, considering the uncertainties of carbon price and the decreasing CCUS investment cost, and the displayed solutions of the option value and investment timing of CCUS investment in coal-fired power plants under different modes are obtained by solving the model. Based on this model, the impact of different policy incentives such as additional power quota, electricity price subsidy, investment subsidy, and carbon price volatility on CCUS investment decisions are further analyzed through numerical examples. On this basis, some policy suggestions are provided finally.

Chemical absorption method is an effective way to capture CO₂ from flue gas of coal burning. Compared with conventional organic amine absorbents, two-phase absorbent can significantly reduce the regenerative energy consumption and the capture cost. A new type of two-phase sorbent is developed, which uses the physical solvent diethylene glycol dimethyl ether as split-phase agent, ethanolamine and hydroxyethyl ethylenediamine as the main agent, and its absorption regeneration performance, viscosity, water phase proportion and phase separation interval is tested. Moreover, nuclear magnetic resonance (NMR) spectroscopy is carried out for the two phases in the sorbent to determine the composition and phase splitting mechanism. The organic amine composition in the formulation is optimized, and the results show that, the absorption and regeneration performance of the optimized absorbent is better than that of the conventional 5 mol/L ethanolamine absorbent. The cyclic absorption capacity can reach 2.086 mol/kg, more than 99% of CO₂ is enriched in water phase, and the flow of the absorbent entering into the regenerator can be reduced by about 40%. The viscosity of the water-rich phase is lower than 10 mPa∙s, the theoretical regeneration energy consumption is 2.688 GJ/t (calculated in CO₂), indicating the new two-phase sorbent has a good industrial application prospect.

In order to effectively deal with the complex electricity and coal market, strengthening the smart fuel management has become an important part of thermal power plant management. Aiming at solving the problems that the coal yard of a coal-fired power station occupies small area, the types of incoming coal are complex, and the coal-fired coal stacking is chaotic, by extracting the coal quality information of historical incoming coal, K-means and DBSCAN clustering algorithms are used to analyze the low-level coal. The calorific value, volatile matter and sulfur content are clustered and analyzed, and the two clustering algorithms are compared from the perspective of silhouette coefficient, cluster stability and sample division fineness, and finally K-means with better clustering effect is selected as the calculation method for coal quality division. The K-means algorithm divides the selected historical coal quality information data set into four categories, the contour coefficient is 0.587, and the coal quality components in each category are similar. The incoming coal frequency and the incoming coal weight ratio under different cluster labels are counted, and the coal yard is divided into corresponding proportions. The incoming coal of the same classification is stacked in each partition, and on this basis, the incoming coal in the digital coal yard platform is designed. Coal stacking guidance and information storage process are of great significance to improving the utilization of storage yard space and the efficiency of coal yard management.

Control of main steam temperature (MST) is becoming more and more challenging because of unknown disturbances caused by frequent and extensive load changes and strict control requirements for the efficiency and safety. To this end, considering the sluggish responses to the disturbances caused by high order dynamics, an anti-disturbance control scheme with stair-like dynamic matrix control (SDMC) algorithm as the core is proposed to solve fundamentally the control problem of large delay, big inertia and multiple disturbances in MST. This study aims to provide technical support for the clean and efficient use of coal and the large-scale consumption of renewable energy sources in China. A simulation example shows that the proposed improved equivalent input disturbance observer (IEIDO) can realize real-time estimation and compensation of disturbances, while SDMC can not only ensure the rapidity and stability of the steam temperature control system, but also achieve disturbance suppression according to the introduction of measured disturbance feed-forward compensation technology. Therefore, the proposed scheme can guarantee the safety, stability, economy and flexibility of the unit operation, which has a promising application future in power industry.

The internal flow and temperature rise characteristics in the last stage of steam turbine low pressure cylinder under low flow rate condition is quite complex, which makes thermal power peak load regulation and cut-off transformation more challenging. By taking the low pressure cylinder of a steam turbine in a power plant as the research object, a five-stage cascade single-channel calculation model of the low pressure cylinder was established, and the working performance, flow structure and temperature rise characteristics of the low-pressure cylinder under different working conditions were numerically investigated. The research shows that, when the flow rate of the low-pressure cylinder decreases to 3.84% of the design condition, the low-pressure cylinder outputs no positive power. When the flow rate is quite low, the low pressure cylinder enters the windage condition, and the flow structures such as the hub endwall separation area, the vane separation area, the casing torus vortex, and the last stage bucket vortex appear in the last stage cascade, by concomitant of obvious windage heating effect at the tip position of rotor-stator clearance area of last stage cascade under low flow rate condition. When the flow rate decreases to 2.23% of the design condition, the average surface temperatures of the last stage vane and blade increase by 219.6 K and 243.7 K, respectively. The working performance and internal flow structure significantly change under windage condition. The temperature rise in the last stage cascade deteriorates the working environment of the blades, which needs to be taken into consideration when the steam turbine works under low flow rate condition.

In the context of Europe's vision of achieving carbon neutrality by 2050, carbon capture, utilization and storage (CCUS) technology, as an important means to achieve carbon emission reduction goals, has embraced a major development opportunity. This paper summarizes the development status of CCUS in Europe, including the financial incentive policies, carbon tax and policies, laws and regulations, and technology innovation policy for the development of CCUS technology in Europe, and the challenges in the process of developing CCUS technology in Europe, including the implementation of public funds, the comprehensive development of CCUS policies, and clear definition of responsibilities for CCUS projects. It points out that up to now, the development of CCUS technology in Europe is relatively mature. Relevant laws and regulations, financial incentives, tax support policies, and technology innovation policies have come into effect. Bioenergy with carbon capture and storage (BECCS) and direct air capture with carbon storage (DACCS) are important means to achieve negative emissions in the future. CO₂ industrial clusters and the development of transportation network can greatly reduce the transportation cost of CO₂, create profits at scale, and thus promote the application of CCUS. In 2020, China made the pledge to achieve carbon peaking by 2030 and achieve carbon neutrality by 2060. Combining the development status and relevant policies of European CCUS with basic national conditions of China, it puts forward the urgent need for current development of CCUS technology in China, and the problems that need to be solved.

A mathematical model of subcritical organic Rankine cycle (ORC) system is established for the flue gas waste heat of 120~150 ℃. Firstly, the thermal performance and economic performance of the system are analyzed at different heat source temperatures by taking R245fa as an example. Then, a multi-objective optimization study is conducted for six pure working fluids based on NSGA-Ⅱ algorithm. At last, working fluid selection and performance analysis of the ORC system with various heat source temperatures are carried out by TOPSIS method and gray correlation analysis. The results show that, in the temperature range of this study, the increase of superheat degree and evaporator pinch point temperature difference is not conducive to improve the system performance. The optimal working fluids are varied at different heat source temperatures, when the heat source temperature is 120 ℃, R601 has the best thermal performance, R245fa has the best economic performance and R1233zd has the best overall performance. The increase of heat source temperature is beneficial to improve the economic performance of the system. The optimal evaporation temperature of each working fluid increases with the heat source temperature. The gray correlation analysis indicates that the comprehensive performance of all six working fluids improves with the heat source temperature.

In recent years, the scale of wind power is growing rapidly, its economic analysis and cost modeling methods are also constantly improving. In order to summarize the existing methods and clarify the follow-up research ideas, the four stages of the whole life cycle of the wind power project are first explained. Then, the cost composition and modeling method of the whole life cycle of wind power projects are introduced, and the differences between onshore and offshore wind farms in this part are compared, and the relationship between life cycle and investment cost is discussed based on the above contents. In order to introduce the benefits of cost investment, the basic economic evaluation indexes and applicability of wind power projects are compared. On this basis, the future development trend is analyzed according to the existing problems, and some suggestions are put forward for the economic evaluation of wind power in different regions and environments. It is hoped that the work of this paper can provide reference for wind power cost modeling and economic evaluation under the new development trend.

This paper studies how to mitigate the blade root flap-wise moment of wind turbine under the influence of wind shear and tower shadow effect. An individual pitch control strategy based on simplex method is proposed to mitigate the blade root flap-wise moment and its 1p component load on the basis of ensuring the power control of the wind turbine. This method and the individual pitch control strategy of conventional PI control are applied to a 4.5 MW wind turbine model, and simulation is carried out under turbulent wind conditions to compare and analyze the blade root flap-wise moment, its power spectral density and the output power. The analysis of the simulation operation data of the 4.5 MW wind turbine model shows that, the individual pitch control strategy based on the simplex method can effectively mitigate the blade root flap-wise moment and its 1p component, and stabilize the output power.

The wake effect of wind farm is the main factor affecting the performance of wind turbines in the downstream wind farm. The wake effect, load characteristics and fatigue damage of wind turbines in front, middle and rear of an offshore wind farm were quantitatively assessed by FAST.Farm, which is the latest opensource multi-physical field coupling simulation software tool of National Renewable Energy Laboratory (NREL). The results show that, the wind speed decreases and the turbulence intensity increases in turn in the wind farm along the flow direction. The fatigue damage of front-row, middle-row and back-row wind turbines increases with the inflow wind speed. Especially, under the condition of high inflow wind speed, the fatigue damage of the middle-row wind turbines at the blade root and the tower base increases exponentially, and the increase range is obviously higher than that of the front and back row wind turbine. It suggests that the structural strength of wind turbines in the central area should be improved to some extent in wind power pre-development and post-operation and maintenance work.