Based on the application of micro-channel printed circuit heat exchangers in fields such as thermoelectric power generation and aerospace, a high-efficiency, low-resistance, and easy-to-manufacture transverse slotted channel is proposed using the theory of boundary layer re-development, and the heat transfer is enhanced. Numerical simulations are employed to study the flow and heat transfer characteristics of both straight and slotted channels. The mechanisms of heat transfer enhancement and flow resistance reduction in the transverse slotted channel are investigated. The results show that the entrance effect can significantly enhance heat transfer with a minimal increase in flow resistance. The transverse slotted channel creates multiple entrance effects in the slotted regions by inducing flow separation, which leads to periodic boundary layer redevelopment, thereby greatly enhancing local convective heat transfer. Additionally, due to the relatively small velocity gradient in the slotted regions, local resistance is effectively reduced. As a result, the proposed transverse slotted channel improves the heat transfer capability of the channel by 2.24%~2.59%, reduces the resistance by 6.66%~7.91%, and increases the overall heat transfer performance by 9.87%~11.02%.

Computational fluid dynamics-chemical reactor network (CFD-CRN) simulation is a suitable method for predicting NO_x emissions from gas turbines. A universal CRN automatic partitioning/solving program was developed and then applied and verified on a natural gas micro-mixing combustor. Through analysis of flow and combustion characteristics in the micro-mixing combustor based on CFD simulation, CRN partitioning criteria are established: firstly, the air and fuel zones are extracted, then major zones along the axial direction are divided, and further the zones are subdivided radially/circumferentially according to fuel-staging locations. The results indicate that, the CRN automatic partitioning/solving program enhances generality by using an XML standardized information interface and is suitable for complex combustor structures. The relative error between the predicted and experimental NO_x emissions under different operating conditions of the micro-mixing combustor is less than 11%, and the influence of CFD grid number on the NO_x prediction by CRN is relatively small. The effect of fuel distribution ratio on NO_x emissions from micro-mixing combustor is analyzed, and a suitable adjustment range is given. The proposed CRN automatic partitioning/solving algorithm has potential applications in predicting NO_x emissions from gas turbines.

A resin-based solid amine adsorbent was prepared based on in-situ synthesis technology. The effects of air humidity (30%~90%), adsorption temperature (30~90 ℃) and adsorption time on the adsorption performance of CO₂ were investigated. Moreover, the adsorption kinetic characteristics of the adsorbents at different air humidities were studied. The results showed that, the maximum CO₂ adsorption capacity of the resin-based solid amine adsorbents in the air reached 2.38 mmol/g, and the air humidity and adsorption temperature had significant effects on the adsorption rate. The optimal adsorption efficiency was obtained when the air humidity was higher than 50% and the adsorption temperature was 25~50 ℃. The adsorbent exhibits very good cycle stability due to its excellent high temperature resistance.

Constructing a large-scale virtual power plant (L-VPP) based on coal-fired units is a vital strategy for achieving “dual-carbon” goals by enabling renewable energy integration and supporting the transition of coal-fired power generation. A dynamic simulation model of the L-VPP and a source-storage frequency regulation control system model are established, which include a 350 MW coal-fired unit, a 100 MW photovoltaic unit, a 90 MW·h battery energy storage system, and internal loads. The frequency response characteristics of the L-VPP are analyzed for various control systems and at different load ramp rates of the coal-fired unit. The results reveal that, the load ramp rate of the coal-fired unit is a critical constraint on frequency response capability when storage capacity is limited. The complementary frequency response characteristics between the source and storage are obtained, leading to a coordinated control strategy that incorporates auxiliary power commands and cyclic determination mechanisms. Simulations demonstrate that the proposed strategy lowers the frequency nadir by 0.06 Hz and shortens the steady-state recovery time by 18.6%. Furthermore, to achieve a steady-state error within the frequency dead band, the load ramp rate of the coal-fired unit is increased from below 3.50 MW/min to 7.00 MW/min. This strategy offers technical guidance for the safe and efficient operation of large-scale virtual power plants.

In order to effectively improve the energy efficiency and operational flexibility of solar power generation, an integrated system coupling solar photovoltaic, solar thermal and compressed air energy storage is proposed. During the day, the compressed air energy storage system will store the photovoltaic abandoned power, and transfer the compression heat to the photothermal power station. At night, the compressed air energy storage system releases air and uses water supply of the photothermal power station to heat up, thereby increasing the power generation load of the unit. Based on the system simulation, the coupling scheme is analyzed thermodynamically and economically. The overall generation efficiency of the coupled system is 41.24%, while the overall exergy efficiency is 66.79%. The round-trip efficiency of the compressed air energy storage system is 72.14%, while the exergy efficiency of the compressed air system is 84.30%, both of which have increased significantly. The peaking depth of the coupled system is 7.02% in the daytime and 19.69% in the evening. In addition, the dynamic recovery cycle of the coupling scheme is 3.10 years, and the net present value is 41.350 6 million yuan.

With the rapid development of energy storage industry and the continuous increase in the installed capacity of energy storage power stations, safety accidents in electrochemical energy-storage power stations have become increasingly frequent, and safety issues have gradually become a key factor restricting the large-scale development of the industry. Therefore, the current policies and standards related to safety risk assessment of electrochemical energy storage power stations at home and abroad are systematically reviewed at first. Then, by analyzing typical safety incidents of electrochemical energy storage power stations, the safety risk points of such power stations are summarized. Based on this, the research progress of the theory and evaluation methods of safety risk assessment of electrochemical energy storage power stations is summarized, from the aspects of battery body, power station working environment, external stimulation and human factors. Finally, the safety development of energy storage power stations in the future is discussed from improving the safety evaluation policies and standards of energy storage power stations, enhancing the construction of the safety assessment system for energy storage power stations, improving the safety and operation management system of energy storage power stations, and strengthening the cultivation of professionals in the energy storage field. It is hoped that this will provide some references for subsequent related researches.

In light of the intricate nature of surface defects in wind turbine blades, conventional convolutional neural networks face problems such as threshold screening and non-maximum suppression processes, which increase computational complexity and are not conducive to model deployment. A novel defect detection model that integrates real-time-detection transformer (RT-DETR) with YOLOv5 algorithm is proposed. Firstly, the backbone network of YOLOv5 is redesigned based on RepVGG and FasterNet to reduce the computational complexity of the model. Recognizing the presence of small-sized targets within the detection tasks, an efficient channel attention (ECA) mechanism is integrated into the neck network’s feature fusion component, thereby augmenting the expressiveness of the output features. Finally, the detection head of original network is reconstructed with the Decoder from RT-DETR, minimizing the effect of non-maximum suppression on the model’s performance. The experimental results show that, the average detection accuracy and accuracy of YOLO-RT are 87.2% and 92.7%, respectively, on a self-constructed dataset of wind turbine blade surface defects, reflecting improvements of 4.4 and 8.0 percentage points over the original YOLOv5 model. The detection rate reaches 118.3 frames per second, surpassing that of alternative detection models. The enhancements introduced in this algorithm significantly improve both detection accuracy and speed, making it highly suitable for practical applications in detecting surface defects on wind turbine blades.

Effective monitoring of chloride ion indicators in precision treated effluent plays a crucial role in ensuring the quality of the effluent, adjusting operational processes, and extending operating cycles. According to the theory of ion exchange equilibrium, the operating characteristics, effluent quality, and resin regeneration requirements of hydrogen type and ammonium type operation modes for precision treatment were analyzed and compared. Through laboratory simulation experiments and tracking experiments of the operating cycle of a precision treated mixed bed in a certain power plant, the migration characteristics of chloride ions in the effluent of precision treatment were mainly studied. The results show that, the requirement for regeneration degree of resin in the hydrogen stage is low, and the main focus of this stage is desalination, which is not prone to chlorine leakage. As the pH value of the effluent increases during the conversion stage, the requirement for resin regeneration also increases. When the condensate contains chloride ions, chloride ion displacement is prone to occur. During ammonium type operation, the mixed bed no longer focuses on desalination, and the mass concentration of chloride ions in the effluent is equivalent to that in the condensate. Therefore, effective monitoring of chloride ions is necessary for ensuring the quality of effluent water, especially during ammonium type operation. At the same time, using chloride ions as one of the monitoring indicators can not only ensure the quality of effluent water effectively, but also guide the adjustment of precision treatment operation process, and significantly extend the precision treatment operation cycle while ensuring the safe operation of the unit.

An analytical model for a combined heat and power (CHP) system driven by deep geothermal energy based on heat pipes was developed. The dynamic heat extraction characteristics of the heat pipes are obtained through numerical calculations based on the heat pipe-geothermal rock layer model. By analyzing the thermodynamic and thermo-economic performance of the direct expansion CHP system, the effects of heat pipe structure (heat pipe diameter, length, and insulation layer length), operating time, and geothermal temperature gradient on the performance of the system are investigated. The results show that, lower steam condensation temperature of the heat pipes leads to greater heat extraction, which helps shorten the investment recovery of the system. However, reducing the condensation temperature also decreases thermal efficiency of the CHP system. Moreover, there exists an optimal steam condensation temperature that minimizes the system’s levelized cost of electricity (LCOE). The heat extraction rate from the heat pipes declines rapidly in the first five years, and then gradually stabilizes. To maintain stable heat extraction over long term (30 years) and avoid interference between adjacent heat pipes, the center distance between any two heat pipes should be kept above 80 meters. The economic performance of the CHP system is closely related to the structural parameters of the heat pipes. At an optimal steam condensation temperature, increasing the heat pipe diameter and length, and selecting target zones with higher geothermal gradients can effectively reduce both the investment payback period and the LCOE.

The dynamic models of steam generation system and power generation system are developed to study the dynamic characteristics of power-to-heat molten salt heat storage and power generation system, and the reliability of the models is validated. The dynamic characteristics of the system are analyzed for the disturbance of molten salt work temperature, flowrate and steam valve opening. Moreover, the performance of the system in the load reduction transient process is investigated in the 100%THA~50%THA load interval. The results show that, the main steam temperature and reheat steam temperature respond quickly to the molten salt temperature disturbance, and their response is obviously faster than that of the unit load and main steam pressure. The molten salt flowrate disturbance has a significant effect on the unit load and main steam pressure, and the unit load increases by 12.44% and the main steam pressure increases by 1.18 MPa with 15% increase in molten salt flowrate. The main steam valve opening controls the main steam pressure and load fluctuation. With the addition of the control system, the maximum load reduction rate of the unit in the 100%THA~50%THA load interval is 14%Pe/min with the limiting condition of temperature deviation.