The signals of flame spontaneous emission (passive method) and absorption spectrum (active method) are two commonly used optical measurement methods for reconstructing the combustion physical field. Developing an active and passive combined method by combining the respective advantages of the two methods will provide a new means for combustion detection. By introducing a laser absorption optical path into the passive measurement system to simultaneously obtain the spontaneous emission and absorption spectral signals of the flame, the combustion temperature field and the initial component concentration field reconstructed by the passive method are introduced into the active method reconstruction. The active and passive combined method is developed by combining the double regularization constraints of smoothness and the prior concentration physical field. Simulation reconstructions are carried out for typical single-peak and double-peak axisymmetric flame sections. When the measurement error is 1.00%, the average errors of the single-peak and double-peak flame combustion temperature field reconstructions are 0.92% and 1.32% respectively, and the average errors of water vapor volume fraction are 3.05% and 3.31% respectively. The results show that under the double regularization constraints, the reconstruction accuracy of water vapor concentration by the active and passive combined method is significantly improved compared with the passive method, and the number of required laser optical paths is greatly reduced compared with that of the active method, achieving accurate measurement of the combustion temperature field and component concentration field using a simple measurement system.

The existing flame radiation image temperature measurement technology has measurement errors due to the coking problem of the detector lens. There is an urgent need for an online monitoring method that can intelligently eliminate the coking interference. An online monitoring method for the temperature field of power station boilers that integrates flame radiation images and convolutional neural network (CNN) is proposed. Firstly, the detector is calibrated via a blackbody furnace, and the relationship between the monochromatic radiation intensity of the detector and the image intensity is established. Secondly, a CNN model suitable for flame image processing is designed, and the training set is constructed by using the non-coking flame radiation intensity images of the boiler collected on-site to establish the flame radiation intensity image restoration model. Finally, the measurement accuracy of this method is verified by using the simulated coking flame images. The results show that the temperature measurement accuracy decreases with the reduction of the number of training sets. When the number of flame images in the learning set is 3 000, the relative error of temperature measurement is 1.4%. The temperature measurement accuracy decreases as the coking area increases. When the coking area is 30%, the maximum relative error of temperature measurement is 0.7%. Furthermore, studies show that when the model of the detector trained by the learning set calculates the coked images of other detectors, the temperature measurement error will increase, with the maximum relative error reaching 34.6%. This indicates that when applying this method, the detectors of each burner need to be trained separately. The proposed method can intelligently eliminate the interference of coking on the flame radiation image, achieve high-precision online monitoring of the temperature field, and provide reliable technical support for the safe operation and combustion optimization of power station boilers.

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 risk of system instability in conventional distributed control systems (DCS) in complex industrial settings which is caused by asynchronous evolution of control configuration data, a dynamic synchronization technology system covering the entire lifecycle of equipment is developed. It delves into the potential risk transmission mechanisms of DCS configuration data during conversion and synchronization, and presents a synchronization assurance mechanism based on dynamic verification and full-chain tracing. By creating a mirrored digital twin mapping model, it enables two-way mapping of configuration data between physical controllers and upper-computer systems. Together with a dual-state cooperative closed-loop synchronization protocol stack, this forms a triple-integrated architecture of “source-storage-operation”. Breaking through the limitations of conventional synchronization modes, this system ensures strong consistency of configuration data even under complex operating conditions. Verified in a thermal power plant’s DCS project, the proposed technical solution significantly improves the control system’s fault-tolerance under abnormal conditions, effectively ensuring safe and stable operation of power generation units. This offers key technological support for the independent and controllable upgrade of critical information infrastructure in the energy sector. The research holds great reference value for similar industrial control systems, and its design concept can be applied to various fields such as process industry and smart manufacturing.

Co-firing sludge is one of the important approaches to address the challenges of urban sludge accumulation. The field test of co-firing sludge dried by flue gas was conducted in a 350 MW supercritical coal-fired power unit to investigate the effects of blending amount and unit load on system operation and energy consumption. Wet sludge was dried using extracted boiler tail flue gas, with the dried sludge subsequently carried into the furnace for co-combustion. The results show that a positive correlation exists between the wet sludge amount and the temperature/flow rate of drying flue gas. Drying 11 t/h wet sludge required 71 t/h flue gas at 597 ℃. As the sludge blending ratio rose, the boiler thermal efficiency decreased, while the auxiliary power consumption ratio increased. The rise in sensible heat loss in exhaust gas mainly led to the decline in boiler thermal efficiency, and the rises in both unburned carbon heat loss in residue and sensible heat loss in residue were secondary factors. The rise in auxiliary power consumption ratio was primarily attributed to the high power consumption of the sludge drying system, with sludge co-combustion system dominating the rise in auxiliary power consumption ratio. The rise in net coal consumption rate was caused by the decline in boiler thermal efficiency and the rise in auxiliary power consumption ratio, and the rise in auxiliary power consumption ratio contributed more significantly. At 262 MW and with a sludge blending mass ratio of 8.76% (sludge moisture fraction: 83%), the boiler thermal efficiency decreased by 0.260%, the auxiliary power consumption ratio increased by 0.466%, and the net coal consumption rate increased by 2.38 g/(kW·h). The study provides a reference foundation for the energy consumption evaluation and optimization of co-firing sludge dried by flue gas in a coal-fired power unit.

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.

Improving the flexibility of coal-fired power generation units is of great significance for ensuring the reliable and stable operation of the power grid. The heat and mass transfer process in the CFB boiler furnace is investigated deeply. It is found that when the load changes, the air volume entering the furnace responds rapidly, driving the change of the particle suspension density in the dilute phase zone, thus triggers the rapid change of the convective heat transfer coefficient and the total heat flux. Different from pulverized coal-fired boilers, the average furnace temperature of the CFB boiler changes little with load. During the load change process, although the heat storage capacity is large, the thermal inertia is not fully manifested, and it does not have a negative impact on the load change rate. Therefore, the load adjustment process of the CFB boiler is based on the rapid response of the heat transfer coefficient under near constant temperature conditions, which is essentially different from the load-changing mechanism of the pulverized coal-fired boiler. In addition, a considerable amount of unburned carbon in the bed material can serve as a potential fuel supply source when the load increases. When the oxygen supply is increased, the combustion rate can be rapidly improved. Combined with the heat storage of bed materials and castable, the CFB boiler can be regarded as having a built-in “energy storage” function, providing long-term energy support for load adjustment. Measures such as reducing the average bed material size, decreasing the feeding coal size, and adding powdered-coal and circulating ash can further increase the load-changing rate of the CFB boiler. The test results on a 300 MW subcritical CFB boiler unit show that the load increasing and decreasing rate can reach 4%~9%Pe/min, approaching the load-changing capability of a gas turbine unit. The research demonstrates that the CFB boiler has the potential for rapid load change in principle and will play a more crucial role in the new power system dominated by renewable energy sources.

Supercritical water coal gasification for hydrogen production is a clean and efficient power generation technology. Based on entropy generation theory, numerical investigation on the non-equilibrium condensation flow of an H₂O/CO₂ mixed working fluid in the final-stage cascade is conducted. The losses are quantified by identifying regions within the cascade where different types of losses occur and calculating the entropy generation in each region. The mechanisms behind the impact of back pressure and CO₂ mass fraction in the mixed fluid changes on various losses and entropy generation sources are analyzed. The effects of these parameters on the loss distribution are explored, including a detailed description of how shock waves influence wake losses and the entropy generation distribution within the boundary layer. The results show that wall losses, wake losses, and boundary layer losses consistently account for over 90% of the total losses under different operating conditions. The main sources of entropy generation are wall dissipation, direct dissipation, and turbulence dissipation. When the back pressure increases by 5.03 kPa, the total loss decreases by 31.73%. However, when the CO₂ mass fraction in the mixed fluid increases by 40%, the total loss increases by 4.71%. The variation in turbulent dissipation entropy generation within the wake loss is the primary cause of the total loss change and is closely linked to the velocity gradients in the flow field. This study offers significant insights for the loss analysis of the wet steam region in mixed medium steam turbines and for aerodynamic optimization.

Carnot battery (CB) is an energy storage technology with the advantages of high energy storage density and low investment cost. The single-stage heat pump of basic Carnot battery have a low coefficient of performance (COP) under high energy storage density conditions, resulting in a phenomenon of high quality but low utilization of heat. In order to solve this problem, a CB using cascaded heat pump (CHP) and supercritical organic Rankine cycle (ORC) is proposed. Through modeling and analysis, the optimal combination of CHP-CB working fluids is obtained, and the effects of waste heat source temperature, high and low temperature heat storage tank temperature, CHP intermediate temperature on system COP, energy conversion efficiency, energy storage density (E_D) and system exergy loss are discussed. The results show that under high energy density conditions, the COP of the CHP-CB is about 23.5% and 26.9% higher than that of the basic CB when the temperature of the low-temperature storage tank is 50 ℃ and 32 ℃, respeetively. When the temperature of the low-temperature storage tank is 30 ℃, the energy conversion efficiency of the CHP-CB can reach 63.11%. The E_D can reach 13.9 kW·h/m³ when the temperature difference between the high- and low-temperature storage tank is 93 ℃, and cascade heating for the heat storage working fluid can be realized.

In order to solve the technical problem that the cooling margin of the cylindrical hole is insufficient at low blowing ratios and the cold flow is separated from the wall at high blowing ratios, based on the tip-covered vortex generator (TCVG), a new type of vortex generator (VG) is proposed, which is called tile-shaped vortex generator (TVG). The conventional cylindrical hole and the cylindrical hole with TVG are numerically simulated. The results show that the film cooling efficiency of the cylindrical hole with TVG is 200% higher than that of the conventional cylindrical hole. Moreover, it solves the problem that the cold flow of the conventional cylindrical film hole will separate from the wall at high blowing ratios. With the increase of TVG width, the film cooling efficiency increases, and tends to be stable when the width reaches twice the film hole diameter. With the increase of TVG height, the suppression effect of TVG on cold flow is weakened, and there is an uncooled gap in the near-field area at high blowing ratios, and the film cooling efficiency shows a downward trend. The expansion angle of TVG has little effect on the film cooling effect, and the optimal expansion angle is 7.5°.