In order to realize compressor blade fouling and surge faults early warning, a typical fault warning method of gas turbine compressor combining thermodynamic model with artificial neural network was proposed. The simulation model of gas turbine thermodynamic performance was built according to the modularization idea, and the dynamic calibration of the model was completed by using the actual operation data of the gas turbine to form a high-precision gas turbine performance analysis model, and the key indicators such as exhaust flow rate, turbine front temperature and heat consumption can be calculated. Based on the thermal performance simulation model and combined with the compressor typical faults expert experience and professional knowledge, the main characteristic parameters affecting compressor faults were determined, and the compressor blade fouling and surge warning models were abstracted. The historical health data were selected to train the models using the artificial neural network algorithm to obtain the deviation curve, and the early warning of typical compressor faults can be realized by monitoring the deviation changes between the predicted value and the measured value of the early warning model, the example to verify the validity of the measured data of a GE 9F gas turbine compressor was given. The results showed that the method can accurately capture the compressor blade fouling and surge faults, and improve the warning time window compared with the traditional threshold alarm method. The research achievement can be directly deployed in the gas turbine power plant and provide real-time guidance for operation and maintenance personnel to make overhaul and maintenance decisions

The large-scale integration of new energy into the grid has caused increased frequency fluctuations in the grid, making the frequency modulation task of thermal power units heavy and frequent, exacerbating the aging of the unit, flywheel energy storage assisted thermal power unit frequency modulation can improve the frequency modulation performance of the unit. The principle of primary frequency modulation of flywheel energy storage auxiliary unit is discussed, and the flywheel energy storage’s frequency modulation characteristics are analyzed. Combining with the world’s largest capacity flywheel energy storage, the full power control strategy for primary frequency modulation of flywheel energy storage auxiliary units is proposed, and applied to the shakedown test of China’s first set of flywheel energy storage auxiliary thermal power unit’s primary frequency modulation to verify the effectiveness of the control strategy. The field test results show that, the primary frequency modulation performance of the flywheel energy storage auxiliary thermal power unit is good. After the proposed primary frequency modulation strategy is adopted, the qualification rate of the primary frequency modulation action of the unit increases by 21.26%, and the integral electricity contribution index of the primary frequency modulation increases by 3.45 times. The primary frequency modulation mode of flywheel energy storage auxiliary thermal power unit has certain guiding significance to solve such problems.

For the wind-solar-thermal-storage complementary power generation system without conventional power supply support, coordinated planning of installed capacity is of great significance to improve the operation economy and utilization rate of the power generation system. A two-layer optimal configuration method is proposed. The upper layer determines the installed capacity of the system with the minimum levelized cost of energy and the abandonment rate as the goal. The lower layer aims to maximize the consumption of new energy power generation and solve the problem of power distribution. The system capacity configuration is obtained by iterative optimization. Then, the optimization results are selected through Nash negotiation. Finally, the simulation analysis is carried out with the data of Hexi area in Gansu Province. The results show that, the levelized cost of energy is 0.306 4 yuan under the optimal capacity configuration of the wind-solar-thermal-storage complementary power generation system. The optimal ratio of the installed capacity of the wind farm plus photovoltaic power station to the installed capacity of the photothermal power station is 6:1. Compared with the wind-solar hybrid power generation system with the same installed capacity, the wind-solar-thermal-storage complementary power generation system has higher stability.

The fouling of heat exchangers and cooling tower fill surfaces in the external cooling water system of synchronous condenser can significantly impede the heat transfer efficiency of cooling towers, posing a serious threat to the safe operation of synchronous condenser. In order to propose more effective anti-fouling measures and elucidate the causes of fouling, this study employed characterization techniques such as SEM-EDS, XRD, FTIR, etc., to analyze the microscopic morphology and chemical composition of fouling samples. Additionally, chemical analysis methods and ICP-MS were used to analyze the makeup of makeup water and circulating water in the system. The test results revealed that the primary components of fouling in the external cooling system are CaCO₃, SiO₂and CaSiO₃. The fouling in the cooling system is closely related to the absence of wastewater discharge measures in the system, high concentration ratios during operation, and the infiltration of regional windblown sand. This research contributes to proposing targeted anti-fouling measures for on-site operation of such cooling systems, ensuring the economic and operational safety of synchronous condenser.

A feedback control strategy based on Kalman filter was proposed to quantitatively study the drive train torsional vibration mitigation of doubly-fed wind turbine, and the control effect of drive train torsional vibration was compared through simulation calculation. Taking the drive train of 7.0 MW doubly-fed wind turbine as the research object, the Kalman filter was used to estimate the twist angle of the drive train, and an additional electromagnetic torque of the generator was designed for torque control based on the estimated torsional speed of low-speed shaft. The load and power generation calculations were compared with virtual damping control and no-damping control over 20 years full life cycle. The results show that, the correlation between the twist angle of the low-speed shaft estimated by the Kalman filter and the actual value can reach 0.99. The key differences between the feedback control based on the Kalman filter, the virtual damping control and the non-damping control are as follows. The equivalent fatigue load of the low-speed shaft of the drive train reduces by 2.11% and 4.89%, respectively. The equivalent fatigue load of the high-speed shaft of the drive train reduces by 1.99% and 4.78%, respectively. The power generation reduces by 200 kW·h and 700 kW·h, respectively. It can be concluded that the Kalman filter has a good estimating effect on the twist angle of drive train, and the designed additional electromagnetic torque based on the estimated torsional speed of low-speed shaft obtained by Kalman filtering has a very good suppression effect on the torsional vibration of the drive train.

A method was proposed to solve the problem of oil sludge treatment environmentally by sending the pretreated oil sludge into a 330 MW pulverized coal boiler co-firing with coal. The combustion characteristics of the oil sludge were studied by thermogravimetric analysis, and it was proved to be easy to ignite with a high calorific value close to coal, which could improve the boiler’s low-load stable combustion ability. Numerical simulation results showed that the combustion center shifted downward slightly after the oil sludge was sent into the boiler, while the NO_x content decreased. The experimental results proved that the minimum stable combustion load rate can be 20.00% by the benefit of oil sludge co-firing. The temperature at the coal-burner layer increased by 30~50 ℃ and the carbon content of the fly ash decreased from 4.79% to 3.80%. The fire detection analog signal of the coal burner was found to be more stable which validated the positive effect of the oil sludge co-firing at low load condition. The boiler efficiency increased by 0.23 percentage point which reduced the net coal consumption rate by 0.7 g/(kW·h). Moreover, about 3.7 t/h coal was saved at 120 MW load. The method was verified to have a significant energy-saving effect.

High temperature steam pipe is an important part of the power plant. In order to coordinate the pipeline thermal expansion and reduce the pipeline thermal expansion stress caused by the higher altitude difference and larger horizontal span, a lot of constant supports and hangers are designed in pipeline. But because friction moment exists on the rotating shafts, constant supports and hangers are not a constant force, the load deviation will make the pipeline deviate from the designed cold and hot line, and the pipeline stress will increase. For controlling the quality of constant supports and hangers, there are two quality performance control indexes among the relevant domestic standards, namely the constant degree and the load deviation degree. This article focuses on the load deviation degree. It finds out that, the load of putting out pin measured by different loading directions is different, resulting in a large difference in load deviation degree due to friction moment of the rotating shaft of the constant supports and hangers. So the load of putting out pin shall not be used as a representative parameter. The study proposes that the average load shall represent the position of the displacement-load curve, which is a representative parameter of constant supports and hangers. A new formula for calculating the average load deviation degree is proposed. It is suggested to modify the related standards to improve the quality of the constant supports and hangers.

The efficient drying pre-treatment and gasification resource utilization of sewage sludge is one of the important ways to realize green and sustainable city development. Firstly, the thermogravimetric reactor was used to study the drying kinetics of sludge. Then, the influence of high temperature-low speed flue gas and low temperature-high speed flue gas on the sludge drying process was clarified based on Fluent numerical simulation. Finally, a new type of sludge and biomass co-gasification co-generation system was established by Aspen Plus, and the thermodynamic performance of the system was discussed. The results show that, the drying process of sludge in thermogravimetric reactor can be divided into the ascending stage, the first decreasing stage and the second decreasing stage, and the decreasing stage is the main stage. The water diffusion coefficients of SW-60 and SW-80 ranged from 6.34×10–6 to 3.72×10–5 m²/s and 3.69×10–5 to 2.60×10–4 m²/s, respectively. The drying activation energy of SW-60 and SW-80 was 9.55 kJ/mol and 28.25 kJ/mol, respectively, with the increase of initial moisture content. In the drying bed, the drying efficiency of high temperature-low speed flue gas is about 2.67 times that of low temperature-high speed flue gas. In the co-generation system, as the biomass blending ratio increases, the input heat, air flow, low heating value of syngas, yield of syngas and potential of co-generation all increase. However, the electrical efficiency, thermal efficiency and system efficiency will decrease slowly. When the biomass blending ratio is 20%, the blend of 30% moisture dry sludge and biomass can produce electrical energy potential and thermal energy potential of 0.61 kW·h and 4.212 MJ per kg, respectively.

Aiming at the lack of quantitative standards and assessment methods in the current comprehensive assessment of wind turbine control performance, a quantitative assessment method of control performance based on subspace linear quadratic Gaussian (LQG) is proposed. The subspace matrix method is used to solve the assessment trade-off curve, and the benchmark and assessment index of LQG control performance of wind turbines are established. By taking the turbine retrofitted by adding tower damping and load shedding control as an example of the assessment, the multivariate comprehensive quantitative assessment of pitch control performance before and after retrofitting is carried out by using two kinds of data processing strategies. The results show that, both data processing strategies can obtain accurate and effective quantitative evaluation results, and the proposed evaluation method can realize the comprehensive quantitative evaluation of the optimization effect of control strategies.

A comprehensive evaluation model for the start-up and shutdown decision-making of the milling system, taking into account the energy consumption and tracking performance of the unit load, has been proposed to address issues such as subjective decision-making based on manual experience, high labor intensity in operation, and difficulty in exploring energy-saving optimization potential. This model safely incorporates the grid load scheduling command signal as input. Furthermore, a milling system start-stop intelligent decision-making method based on deep reinforcement learning has been studied, and a closed-loop control system for the automatic start-stop of the milling system has been developed. The research results have been verified through simulation and successfully applied to a commonly used coal milling system in a certain ultra-supercritical 1 000 MW unit, achieving energy savings. The findings of this study can provide effective reference for the development of unmanned or minimally manned operation techniques for thermal power units.