The intermittency and volatility of renewable energy generation poses significant challenges to grid integration. A waste heat-coupled Carnot battery system, based on heat pumps and organic Rankine cycles, is considered a potential solution. However, the system’s power-to-power efficiency is greatly affected by waste heat temperature. To address this issue, a novel high-efficiency Carnot battery system is proposed, utilizing vapor injection and regeneration technologies in the charging and discharging modules, respectively. A thermodynamic model is developed to investigate the cycle performance of the system under various operating conditions. Additionally, the energy consumption and economic viability of the system are analyzed in three representative cities: Guangzhou, Nanjing, and Harbin. The results indicate that, the power-to-power efficiency increases with higher heat source temperatures and lower ambient temperatures. Moreover, the new system features an optimal intermediate pressure during both the charging and discharging processes, maximizing efficiency. Compared with the conventional Carnot battery systems, the new system demonstrates a 21.8%, 22.5%, and 23.6% increase in daily average power to power efficiency in Guangzhou, Nanjing, and Harbin, respectively. Furthermore, the annual net income increases by 45.6%, 52.8%, and 50.2% in these cities, respectively. This study provides theoretical guidance for enhancing the efficiency of Carnot battery systems.

The growing share of renewable energy leads to increased load volatility and uncertainty in power system, necessitating greater flexibility in cogeneration systems. The utilization of molten salt thermal storage equipment can enhance the performance of cogeneration systems. Against the main-pipeline cogeneration system consisting of four boilers and two steam turbines which is integrated with a coupled molten salt thermal storage equipment, the EBSILON simulation software is used to establish mechanism model for power supply and heating. The influence of molten salt heat storage equipment on combined heat and power system performance is analyzed, and the optimization scheduling methods for coupled systems are also investigated. The results show that, the coupling of molten salt thermal storage equipment in cogeneration systems can increase the system’s peak shaving capacity, expand the system’s operating range, and broaden the unit’s operating area. After estimation, the amount of coal saved in one day can be about 4.16 tons, the carbon emissions can be reduced by about 8.25 tons, and the pollutant emissions can be decreased by about 1.76 kg. The molten salt thermal storage equipment has improved the system’s economy and environmental friendliness.

To investigate the effect of blending ratio on co-combustion characteristics of sludge hydrothermal carbon and municipal solid waste, and reveal the interaction between the two materials, thermogravimetric analyzer is used to test the combustion characteristics of sludge hydrothermal carbon, municipal solid waste and mixed samples. The combustion kinetics of the samples were analyzed by Coats-Redfern method. Based on the difference between the experimental combustion characteristics and the theoretical combustion characteristics of the mixed samples, the interactions between the two materials was revealed. The results showed that, the ignition temperatures and burnout temperatures of the mixed samples decreased with the increase of sludge hydrothermal carbon blending ratio, but the combustion rate also decreased, resulting in a decrease of the comprehensive combustion characteristic index. As the blending ratio of sludge hydrothermal carbon increased from 0% to 80%, the comprehensive combustion characteristic index of mixed sample decreased by 71.8%. With the increase of sludge hydrothermal carbon blending ratio, the activation energy of volatile combustion stage decreased, while the activation energy of char combustion stage increased. There was a significant interaction between sludge hydrothermal carbon and municipal solid waste, which can inhibit the combustion of volatiles. In the blending ratio range of 20%~80%, the comprehensive combustion characteristic index of the mixture decreased by 12.9% on average. The research results can provide data reference and theoretical basis for the control of the working condition and the design of ACC automatic control system in the municipal solid waste incineration plant.

Overdue service of thermal power units has become a trend, but fatigue crack of turbine rotor steel seriously affects the operation safety of steam turbine units. Due to the lack of the fatigue crack growth (FCG) test data of rotor steel, and large computation cost for stochastic model modeling and solution, the estimation of fatigue crack remaining useful life (RUL) is currently insufficient. On the basis of fatigue crack growth tests and analysis on its random models, a modified Gaussian membership information expanded (GMIE) sample domain method is proposed to generate virtual samples based on mega trend diffusion (MTD). Meanwhile, an extreme machine learning (ELM) neural network combined with the expective regression (ER) model is used to predict the RUL of fatigue crack propagation. The RUL of fatigue crack propagation under a specific cycle is calculated. By comparing the results with the RUL probability density function (PDF) curve and fatigue crack propagation curve of the existing numerical analysis methods, it shows that mean absolute percentage error (δ_MAPE) is 2.78%, which verifies the effectiveness of the proposed method and provides robust support for safe operation of the turbine rotor systems.

As a key component of air source heat pump, the thermodynamic performance of scroll compressor has an important influence on the heat pump system. A three-dimensional transient simulation model of the scroll compressor is established, and the accuracy of the model is verified through experiments. Based on computational fluid dynamics method, the non-uniformly distributed flow characteristics of internal flow field of the scroll compressor under the influence of tangential leakage flow are investigated. The influence of different operating conditions on thermodynamic performance of the scroll compressor is explored. The sensitivity analysis method is used to discuss the sensitivity of thermodynamic performance of the scroll compressor under different operating conditions. The results show that, with the increase of pressure ratio, the isentropic efficiency increases at first and then decreases, the heat production decreases, the maximum increase in time-averaged exhaust temperature is 11.26 K. When the suction temperature increases to 311.65 K, the isentropic efficiency grows by 16.72 percentage points. The increase of rotational speed will weaken the phenomenon of reflux and reduce the exhaust temperature, when the rotational speed rises to 4 500 r/min, the volumetric and isentropic efficiencies increase to 86.61% and 46.86%, respectively.

The recent advancements in key materials including reactants and catalysts employed in solid-gas, gas-gas, and liquid-gas solar thermochemical energy storage (TCES) systems are reviewed. The thermochemical properties of reactants such as carbonates, hydroxides, metal hydrides, metal oxides, organics, and ammonia are examined. The research status of the modification of these reactants, new material development, and catalyst improvement are also discussed. At present, the reactant materials suitable for solar TCES exhibit various deficiencies in terms of cyclic stability, reactivity, conversion rate, energy storage density, cost or safety, which hinder the commercial viability of solar TCES technology. To further enhance the maturity of solar TCES technology, it is imperative to develop advanced composite materials on the basis of known thermochemical reaction systems, improve novel efficient catalysts, and broaden demonstration application scenarios and scales in the future. The key materials should endow TCES systems with high energy storage density, more robust cyclic stability, and rapider reaction kinetics. It is preferred that they are readily available, non-corrosive, and non-toxic and more cost-effective.

To address issues such as data information security and difficulty in centralized management and control of data assets, a prototype system for data lifecycle security protection in power plant scenarios is designed. Firstly, the particularity and existing problems of the current field of power plant data protection scenarios are analyzed in detailed. Secondly, in response to the pain point of the lack of industry standards for data classification and grading in power plants, an automated classification and grading method is proposed to standardize the grading and classification of power plant data. Finally, in terms of system development, based on the analysis of the scope of power plant data protection and functional requirements, the functional architecture design and technical architecture design of the prototype system are completed. This system provides specific work steps from data asset sorting, automated classification and grading, full lifecycle management, security assessment, and other aspects, providing a complete solution for data security protection in power plants, and providing a basis for effectively achieving full lifecycle security of power plant data in the future.

The oxy-fuel combustion technology and natural gas blending with hydrogen technology have good engineering application prospects in reducing system carbon emissions and promoting the integration of new energy sources. In response to the low efficiency of post combustion capture mode in integrated energy systems containing a high proportion of renewable energy, as well as the underutilization of oxygen and reaction heat generated during the electric to gas conversion process, a comprehensive energy system is established by supplying products from different stages of the electric to gas conversion process to oxy-fuel combustion power plants and gas turbines, and jointly operating oxy-fuel combustion power plants and hydrogen doped gas equipment. Based on the introduction of a reward-penalty carbon trading mechanism, a low-carbon economic dispatch model for comprehensive energy systems is established with the goal of minimizing comprehensive costs such as carbon trading costs, gas purchase costs, and coal consumption costs. Simulation analysis of case studies shows that, the proposed model can effectively reduce operating costs and system carbon emissions. The research provides a reference for the development of integrated energy systems.

Three-dimensional numerical models of solar enhanced indirect air-cooling tower are established, and the effect of apex angle of radiators on thermo-flow performance of the tower and the varying mechanisms caused by environmental crosswind are evaluated. The distributions of air inflow and temperature fields inside and outside the tower, as well as the airflow rate and heat transfer in different cooling sectors are analyzed. The performance comparison is carried out between scenarios with and without solar radiation. The results show that, under crosswind, the flow characteristics and heat transfer properties of the tower improve with the increasing apex angle of the radiators, and the enhancement effect of solar radiation on tower performance also increases. Crosswinds enhance the performance of the radiators in the windward sector while weakening the performance of the radiators in the crosswind sector and leeward sector. Additionally, solar radiation improves the performance of the radiators in each sector, but if secondary heat transfer rate occurs in the sector, solar radiation may instead weaken the heat transfer rate performance of the radiators in that sector. When the apex angle of the radiators increases from 60° to 120°, solar radiation enhances the increase rate of the average air inflow rate of the tower at various wind speeds increase from 0.66% to 3.18%. Concurrently, the increase rate of the average heat transfer rate increase from virtually unchanged to 3.12%. The enhancement effect of solar radiation on the tower increases with apex angle of the radiators. Therefore, the tower with radiators apex angle of 120° has the optimum thermo-flow performance.

To meet the urgent need for enhanced grid regulation capabilities due to the high penetration of renewable energy and to resolve load-source imbalances, the optimization configuration method for a wind-solar-hydrogen gas turbine complementary system is investigated. The data-driven model for a gas turbine combined cycle unit that considering start-stop dynamics and hydrogen-blending combustion is developed, along with theoretical models for photovoltaic arrays, wind turbines, and electrolyzers. An energy distribution strategy for the system is proposed, and the system capacity configuration optimization model based on MOPSO algorithm is established. With the objectives of minimizing the levelized cost of electricity, load-source deviation and annual carbon emissions, the capacity configuration of the complementary system is optimized. The results demonstrate that, using selected meteorological and load data, the system equipped with 85.28 MW wind turbines, 108.69 MW photovoltaic arrays, 78.02 MW electrolyzers, and a 139 302 m³ hydrogen storage tank can achieve up to a 6% reduction in annual carbon emissions and a load-source deviation of only 0.02%. This validates that the system architecture integrating electrolyzer-gas turbine can effectively mitigate load-source deviation issues in power grid.