Using energy analysis and exergy analysis methods, and considering the irreversible losses in the compression, expansion, and heat-exchange processes comprehensively, the performance indicators and irreversible loss distribution characteristics between a basic PTES (BC-PTES) system and an electric heater-integrated PTES (EH-PTES) system under defined operational conditions are compared, and the influence of key parameters on the EH-PTES system’s performance is investigated. The results indicate that both the BC-PTES and EH-PTES systems generate large exergy losses in the turbine during the discharge, with values of 456 kW and 455 kW respectively. The EH-PTES system demonstrates higher round-trip efficiency (41.50%) and energy storage density (54.1 kW·h/m³), with the exergy efficiency of the electric heater at 63%. Parameter analysis reveals that there exists an optimal discharge-phase compressor outlet pressure which can minimize the exergy loss and maximize system round-trip efficiency. For the EH-PTES system, at the optimal discharge pressure, the round-trip efficiency of the EH-PTES system initially decreases and then increases with the rising electric heater outlet temperature, and it increases with the compressor outlet temperature. For example, when the compressor outlet temperature is 550 ℃ and the electric heater outlet temperature increases from 600 ℃ to 1 000 ℃, the EH-PTES system round-trip efficiency decreases from 45.03% to 44.81% at first, and subsequently increases to 45.75%. When the electric heater outlet temperature is 850 ℃ and the compressor outlet temperature increases from 400 ℃ to 550 ℃, the system round-trip efficiency increases from 39.17% to 45.14%. Notably, the round-trip efficiency is less sensitive to the electric heater outlet temperature than to the compressor outlet temperature. By integrating electric heaters, the energy storage density can be substantially enhanced, reaching 113.9 kW·h/m³ at an electric heater outlet temperature of 1 000 ℃. These findings provide critical insights for optimizing the PTES system design.

Current researches on advanced adiabatic compressed air energy storage (AA-CAES) systems primarily focus on optimizing designs and analyzing performance under off-design conditions based on fixed system structures, with limited attention to system-level optimization involving predefined operational modes. By taking a 300 MW-class asymmetric AA-CAES system featuring four-stage compression and three-stage expansion as the object, a novel variable-pressure (sliding-pressure) operation strategy is proposed, along with a matching design between compression and expansion stages. A quasi-dynamic thermodynamic model is developed to analyze and optimize the full charge-discharge cycle performance under fixed time constraints with sliding-pressure control. The results show that the optimized sliding-pressure mode improves the system’s round-trip efficiency to 73.32%, increases the energy density to 3.404 kW·h/m³, and reduces the required air storage volume to 440 000 m³ (only one-fourth of that under constant-pressure operation). Exergy losses are mainly concentrated in the compressors and turbines, accounting for 40.7% and 29.3% respectively. The isentropic efficiency and heat recovery capability of these components has significant influence on overall performance of the system.

As the power supply structure gradually shifts toward a diversified pattern, the risk of regional renewable energy consumption increases. In order to maximize the utilization of the existing adjustment capacity of hydropower and thermal power and improve the consumption level of wind power and photovoltaic power, a multi-energy complementary energy base including wind power, photovoltaic power, hydropower, thermal power and energy storage is constructed, and the advantages of complementary power generation among wind power, photovoltaic power, hydropower, thermal power and energy storage compared to other power generation modes are analyzed. Based on 8 760 time series points throughout the year, a multi-objective power generation capacity planning model that takes into account system reliability, economic benefits, environmental benefits, and the consumption level of renewable energy is constructed, and multi-objective optimization is achieved through the linear weighting method of unit standardization of the objective function. Finally, the annual historical wind and solar data of a certain place are selected for simulation experiments. The results show that, compared with single-objective optimization, multi-objective optimization can effectively balance the equilibrium points among different optimization objectives, avoid the limitations of single-objective optimization, and by rationally adjusting the output of hydropower, thermal power and energy storage, the complementary coordination of wind power, photovoltaic power, hydropower, thermal power and energy storage on multi-time scales can be achieved.

A Carnot battery system based on coal-fired power units can efficiently absorb curtailed power of new energy while utilizing the existing infrastructure of coal-fired plants for energy release, thereby addressing the challenges posed by high-penetration renewable energy on the power supply-side flexibility. A novel supercritical carbon dioxide reverse Brayton-Rankine cycle Carnot battery system is proposed based on the concept of split-flow expansion, and a comprehensive investigation is conducted through thermodynamic modeling in EBSILON Professional, parameter sensitivity analysis, and multi-objective optimization using genetic algorithms. The results indicate that under design conditions, the turbine power output and waste heat recovery of the novel system are improved by 59.84% and 43.23%, respectively, compared to the reference system. The energy storage cycle achieves a coefficient of performance (COP) of 1.32 and a round-trip efficiency (RTE) of 57.68%, representing an increase of 0.10 in COP and 4.37 percentage points in RTE over the reference system. Both COP and RTE increase with higher pressure ratios, higher flow split ratios, and lower top-end temperature differences in recuperator 2. When the flow split ratio is 0.23, the pressure ratio is 3.09, and the top-end temperature difference in recuperator 2 is 12.60 ℃, the COP of the Carnot battery storage cycle reaches a maximum of 1.37, with a corresponding RTE of 59.87%. The study provides a technical reference for enhancing the operational flexibility of coal-fired power plants and optimizing renewable energy integration through advanced thermal storage technologies.

In the new power system, due to the constantly rising proportion of new energy generation and its own uncertainty, anti-disturbance has become the core task of power control of thermal power units. At present, the power control system of thermal power plants continues to use PID controllers, making it challenging to accommodate the needs for deep, continuous, and frequent peak shaving and frequency regulation in thermal power units. The advanced control theory has an outstanding contradiction between theoretical rigor and industrial practicability, in order to make it better applied in power control of thermal power units, the smooth application of linear active disturbance rejection control (LADRC) is realized by using the engineering basis of PID control. By analyzing the structure of LADRC and the transfer function of the feedback loop, the PID realization form of LADRC is defined and verified by Simulink simulation. The simulation and engineering application tests show that the PID implementation of LADRC inherits the outstanding disturbance rejection ability of ADRC. Under the same PID and related parameters, the PID implementation of LADRC shows outstanding suppression ability to all kinds of disturbance signals, and the third-order LADRC has the strongest disturbance rejection ability and the fastest adjustment speed. The PID implementation of LADRC can meet the requirements of power control system of thermal power units, and the control quality is better than that of conventional PID control. The PID implementation of LADRC expands the engineering application space of LADRC.

To address the intermittent and unstable power output issues in hydrogen production from renewable energy sources such as wind and solar power, it is crucial to achieve the optimal configuration of green power hydrogen production equipment. The discrete combinatorial optimization algorithms and multi-objective shuffled frog leaping algorithms are study introduced to conduct optimization research on the planning of parks with pure photovoltaic, pure wind power, and photovoltaic-wind power hybrid systems for renewable energy generation. Models of electrolyzer system efficiency, operating power, cost, and capacity are constructed. The results show that in a hybrid system with a photovoltaic capacity of 2.60 MW and a wind power capacity of 3.80 MW, the lowest hydrogen levelized cost is 17.83 yuan/kg, and the full-load operating hours of the electrolyzer are approximately 3 400 hours. After optimization by the multi-objective shuffled frog leaping algorithm, the optimal configuration is a photovoltaic capacity of 1.50 MW and a wind power capacity of 0.55 MW, with a maximum hydrogen production of 2 949.62 kg. The photovoltaic-wind power hybrid system can not only reduce the hydrogen levelized cost but also increase the full-load operating time, providing a theoretical reference for the scientific planning of hydrogen production from renewable energy in the future.

With the continuous expansion of the scale of urban heating network systems and the sustained growth of intelligent demands, the conventional centralized control systems based on the single-controller mode have gradually exposed technical bottlenecks in terms of computing power support, system fault tolerance, equipment compatibility, and deployment costs, and have been unable to meet the application requirements of multi-domain collaboration and intelligent optimization control. To this end, a new type of redundant computing engine for multi-domain collaborative control of the heat network is proposed. A hierarchical architecture is adopted and the computing engine is decoupled into two major modules: the management program and the kernel program, achieving the separation of overall management and core computing functions. Through the task hierarchical management and coordination scheduling mechanism, the efficient collaboration of periodic and aperiodic mixed computing tasks has been achieved, improving the operational efficiency and real-time response capability of the system. Adding a redundancy mechanism and proposing a hot standby redundancy synchronization scheme have improved the reliability and stability of the system in high-load scenarios. A unified system supporting the flexible access of multi-language heterogeneous intelligent algorithms has been constructed. Through the dynamic loading and interface mapping mechanism, the two-way interaction between graphical configuration and the underlying algorithm code has been achieved. This computing engine effectively enhances the deployment flexibility and execution efficiency of intelligent algorithms, improves the stability and reliability of system operation. In actual deployment, the loading success rate of intelligent algorithms is 100%, the primary and backup switching time is ≤200 ms, and at the same time the conventional hardware deployment cost is reduced, providing a high-performance and low-cost solution for the intelligent transformation of industrial control systems. Furthermore, it has the potential to be promoted in multiple fields such as energy and transportation.

The resource-recycling of retired crystalline-silicon photovoltaic cells is of great significance for the recycling of materials and the green and healthy development of renewable energy. Currently, most recyclers of decommissioned photovoltaic modules mainly focus on the recycling of aluminium frames, while aluminium resources in crystalline-silicon solar cells have not been effectively recycled, leaving valuable silver within the cells. Therefore, a wet-recycling process for preparing silver powder was proposed, which involves leaching aluminum with liquid alkali, leaching silver with nitric acid, and liquid-phase reduction. By optimizing the experimental parameters, under the conditions of a sodium-hydroxide concentration of 1.0 mol/L, a temperature of 20 ℃, a liquid-to-solid ratio of 10:1 (mL/g), and a reaction time of 40 min, the leaching rate of aluminum from the retired crystalline-silicon photovoltaic cells reached 98.88%, and the leaching-loss rate of silicon was only 0.46%. Under the conditions of a nitric-acid concentration of 4.0 mol/L, a temperature of 70 ℃, a liquid-to-solid ratio of 5:1 (mL/g), and a reaction time of 60 min, the leaching rate of silver reached 98.00%. Using ascorbic acid as a reducing agent, silver powder with a purity of over 99.9% was successfully prepared under the conditions of a molar ratio of ascorbic acid to silver ions of 1.25:1.00, a temperature of 30 ℃, and a stirring speed of 250 r/min. This process achieves high recovery rates and product purity, offering a practical pathway for crystalline silicon solar cell wafers recycling.

The Brayton cycle-based tower solar thermal power system features a flexible layout and operates at high receiver temperatures. However, fluctuations in solar irradiance can lead to thermal fatigue of receiver materials or excessive surface temperatures, necessitating effective strategies to mitigate temperature fluctuations. This study develops a manganese-based thermochemical thermal protection coating utilizing a reversible redox reaction. When solar radiation intensifies and the temperature exceeds 978 ℃, the coating undergoes a reduction endothermic reaction, reducing the heating rate. Conversely, when solar radiation decreases and the temperature drops below 878 ℃, an oxidation exothermic reaction occurs, slowing the cooling rate, thereby stabilizing receiver surface temperature fluctuations. Experimental results indicate that when the mass ratio of the coating material to the binder is 4:3, the adhesion strength reaches the highest national standard level, and the solar weighed average absorptivity achieves 94.93%. After undergoing 500 hours of thermal aging at 950 ℃, 100 cycles of thermal cycling, and 200 cycles of redox reaction tests, the coating’s weighed average absorptivity decreased by only 0.82, 0.98, and 2.61 percentage points, respectively, while maintaining the highest adhesion strength. Under a sudden change in concentrated solar radiation flux of ±9.7 kW/m², the heating and cooling rates in the first 100 seconds were reduced by 59.66% and 67.09%, respectively. Additionally, the time required for a 20 ℃ increase and decrease was extended by 182.50% and 438.60%, respectively. The manganese-based thermochemical coating demonstrates excellent aging resistance and effectively suppresses absorber temperature fluctuations, making it highly promising for applications in Brayton cycle-based tower solar thermal power systems.