An efficient integrated power generation system of solid waste coupled with anaerobic fermentation and incineration is proposed. Solid waste anaerobic fermentation is adopted to generate biogas, which enters the biogas burner to burn and generates high-temperature flue gas, and the flue gas heats the steam-water system and the primary and secondary air through the heater and air preheater in the unit. Under the condition that the heat generated by solid waste incineration in the boiler is not changed, the energy entering the steam turbine to do work is increased, thus the power generation efficiency of the whole unit increases. At the same time, according to the first law of thermodynamics and the second law of thermodynamics, the reasons for power generation efficiency and exergy efficiency improvement are analyzed. The results show that, compared with the case unit, the proposed high-temperature flue gas system with biogas combustion can increase the net power generation by 8.69 MW. In addition, the power generation efficiency and power generation exergy efficiency of the new system has increased by 3.56 percentage points and 9.74 percentage points, respectively. Economic analysis shows that the proposed coupling system is equipped with an anaerobic fermentation biogas combustion system, and the dynamic recovery period is 3.78 years, which has obvious economic advantages.

In order to study the corrosion behaviors of candidate materials for superheater of supercritical boilers in high-temperature flue gas environment, three austenitic heat-resistant steels including S31042, S31035 and C-HRA-5 were exposed to laboratorial simulated coal-fired flue gas for hot corrosion tests. The tests were carried out at 650, 675, 700 and 725 ℃. On the sample surface, there were three conditions including no coating, coating with real coal ash, and coating with corrosive simulated coal ash. The test duration was 500 h. The corrosion kinetic curves of the three materials were obtained through experimental research, and corrosion behaviors of the material were analyzed by XRD, SEM and EDS. Moreover, corrosion resistance of the three materials was compared. The results indicated that, the three materials had excellent resistance to oxidation and corrosion under the conditions of no coating and coating with real coal ash. Under the condition of coating with corrosive simulated coal ash, the material corrosion intensifies and the corrosion products are layered. The temperature effect was different under different coating conditions. S31042 had the best corrosion resistance, and the corrosion resistance of S31035 and C-HRA-5 materials was comparable.

Voltage transformer (TV) interturn short circuit at generator outlet will cause unbalanced voltage in system, resulting in zero sequence stator ground fault protection of generator fundamental. The external characteristics of TV fault are of great significance to stable operation of the unit. In order to understand the external characteristics of TV fault, based on Maxwell and Simplorer software, a field circuit direct coupling finite element model for the electromagnetic conversion process of single-phase voltage transformer is established, which can realize data exchange between field circuits at each calculation step. In view of the large number of turns of TV primary winding, which is difficult to model directly, winding grouping technology is proposed. An experimental platform is designed and built to verify the accuracy of the simulation model. Based on the calculation results of finite element eigenvalues, the electrical and magnetic eigenvalues of TV in different operating states are analyzed, and the analytical model of TV inter turn fault based on winding grouping technology is further given. The simulation results show that, the TV turn-to-turn fault model is accurate and effective in analyzing the primary current, circulating current and other fault characteristic quantities.

In the point cloud splicing of underground pipe gallery in power plants, an improved algorithm with 3D-Harris operator about corner detection is proposed. In this algorithm, firstly, taking multiple sets of massive point cloud data of the underground pipe gallery as analysis object, the normal information of the target detection point on the adjacent point cloud microtangent plane is obtained through principal component analysis method, thus the boundary points of the point cloud are extracted. Secondly, the covariance matrix is constructed according to the normal information of the target detection point, then the corner response intensity function is calculated and compared, and some points are selected as calculation objects to judge whether they are true corner. Thirdly, the pseudo angles are filtered out and the true angles are selected by using a pseudoangle detection method based on Gaussian curvature extreme points. At last, the fast point feature histogram method is used to match similar corners between each group, and the nearest point search point cloud registration algorithm is used to realize the splicing of multiple points and cloud in the underground pipe gallery. The results are compared with that of the conventional 3D-Harris angular point detection algorithm. It is proved that the method in paper takes less time to calculate and has a higher corner-point extraction accuracy, which can realize accurate splicing of massive point cloud of underground pipe gallery.

The high-temperature and high-pressure (300 ℃/10 MPa) corrosion electrochemical behavior and oxide film microscopic features of Incoloy 800H alloy aged at 675 ℃ for 0~10 000 h in alkaline environament were investigated systematically. By means of electrochemical test, long-term immersion test, scanning electron microscope/transmission electron microscope observation, Raman spectroscopy/fast Fourier transform analysis and other methods, the electrochemical activity, evolution of oxide film morphology and composition characteristics of the 800H alloy with extension of aging time were systematically studied. The results show that, the value of open circuit potential and self-corrosion potential E_corr of the 800H alloy in high-temperature and high-pressure water can be slightly increased by aging treatment, but the effect of aging time extension on the electrochemical behavior was not significant. A passive to trans-passive process was depicted. The oxide film of the 800H alloy formed in high-temperature and high-pressure water had a multilayer structure: the most outer layer was the dispersed large particle oxides composed of Fe₂O₃ or NiFe₂O₄; the middle layer was relatively compact small size oxides, mostly NiFe₂O₄ or FeCr₂O₄; while the inner layer was dense and continuous oxides, amorphous or nanocrystalline oxide containing Cr and a small amount of Fe. The 800H alloy has good corrosion resistance and surface stability in alkaline high temperature and high pressure water of 300 ℃/10 MPa.

In order to build a new power system with new energy as the main body, thermal power unit should undertake the new task of flexible operation and deep peak-regulating while maintaining power and heating supply. However, the conventional detection and communication technology is limited by the problems of poor real-time performance, slow transmission and high investment, which is difficult to support the new demand of thermal power units. Advanced detection technology and communication technology represented by 5G provide solid technical support for the state research, judgment and operation adjustment of thermal power units represented by boiler system by building a complete perceptual transmission chain, but they also face problems such as high construction investment, lack of professionals and standards. Only by setting out from the actual production, perfecting the mechanism and changing the concept, can the application effect of advanced detection and communication technology be realized. As an important part of smart power plant, the advanced detection and 5G technology will provide a solid foundation for improving the overall intelligent level of thermal power generation.