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Offshore wind power is an important development trend in the field of renewable energy in China in the future. Firstly, this paper summarized the current development of domestic offshore wind power industry, analyzed the development trend of domestic offshore wind power industry chain, and then introduced the current cutting-edge technology of offshore wind power industry from the subdivided technical field. It mainly covers unit technology, including blade design and pitch control, transmission chain, motor, converter, main control system, etc; networking transmission technology, including AC, DC and low-frequency transmission technology, as well as compact and lightweight offshore platform design technology; engineering construction technology, mainly including offshore engineering, wind farm construction and submarine cable technology; offshore wind power operation and maintenance technologies, mainly including offshore wind power prediction, wake prediction, optimal dispatching, monitoring and maintenance, etc. The research results can provide the reference for the development of offshore wind power in China.

In order to optimize the application effect of induction heating (IH) tundishes, a four-channel IH tundish is taken as the research object. Based on numerical simulation methods, the influence of different relative placement angles of induction heaters and channels on the electromagnetic field, flow field and temperature field of the tundish is investigated. We focus on comparing the magnetic flux density (B) and electromagnetic force (EMF) distribution of the channel. The results show that regardless of the relative placement angle between the heater and the channel, the distribution of B in the central circular cross-section of the channel is eccentric. When the heater rotates around channel 1 towards the bottom of the tundish, the distribution of B in the central circular cross-section of the channel changes from a horizontal eccentricity to a vertical one. Through the analysis of the B contour in the longitudinal section of the channel, the difference in effective magnetic flux density area (ΔAB) between the upper and lower parts of the channel can be obtained, thereby quantitatively analyzing the distribution of B in this section. The distribution pattern of ΔAB is consistent with the distribution pattern of the electromagnetic force in the vertical direction (FZ) of the channel centerline. The ΔAB and FZ of channel 1 gradually increase as the heater rotates downwards, while those of channel 2 reach their maximum value at a rotation angle of 60°. Compared to the conventional placement, when the heater rotation angle is 60°, the outlet flow velocities at channel 1 and channel 2 decrease by 15% and 12%, respectively. However, the outlet temperature at channel 2 increases by 1.96 K, and the molten steel flow at the outlet of channel 1 and channel 2 no longer exhibits significant downward flow. This shows that when the heater rotation angle is 60°, it has a dual advantage. On the one hand, it is helpful to reduce the erosion of the molten steel on the channel and the bottom of the discharging chamber, and on the other hand, it can more effectively exert the heating effect of the induction heater on the molten steel in the channel. This presents a new approach to enhance the application effectiveness of IH tundish. [ABSTRACT FROM AUTHOR]

The effect of a dissipative ladle shroud (DLS) on mixing in tundish was investigated, compared with that of a conventional ladle shroud (CLS) using mathematical and physical modelling. The tracer profiles of mathematical results, achieved using large eddy simulation, were validated by physical observations employing high-speed cinephotography. The design of a DLS dramatically changed the flow patterns and contributed the intermixing of fluid elements inside the ladle shroud. The vortex flow encouraged the turbulent mixing and was verified by tracking of physical tracer dispersion inside the DLS. Residence Time Distribution (RTD) curves were obtained in two different sized tundishes to examine the mixing behaviours. The findings indicated that the DLS benefited the tundish mixing in terms of increasing active volume. The effect seemed to be more remarkable in the smaller tundish. The DLS gave rise to a more plug-like flow pattern inside the tundish, showing potential to shorten the transition length during grade change.

Slag eyes are the upper exposed areas of molten steel in a refining ladle that are formed due to excessive bottom argon bubbling. This phenomenon frequently occurs in the steel-refining process and can lead to slag entrapment and re-oxidation of molten steel. Taking a 150-t industrial steel ladle as the research object, the effects of a dual-plug gas-blown process on the slag-eye size were studied using hydraulic modeling and large-eddy simulations. The experimental results showed that at higher gas flow rates such as 9.1 and 11.7 normal liters/min (Nl/min), the relative central angle of the two porous plugs had a significant effect on the slag-eye size; conversely, at lower gas flow rates, its influence could be ignored. Due to the tendency of the two small slag eyes to merge, the 0.6R–45° (R being the bottom radius of the ladle) case resulted in a larger total slag-eye area compared to the cases with other angles. The 0.6R–135° case showed the most beneficial results for reducing the slag-eye size. Additionally, the numerical simulations helped us to visualize the bubble-uplifting and slag-eye formation processes, and they allowed an exploration of the slag-entrapment mechanism. The simulation results showed that the symmetric gas-blown mode can reduce slag entrapment when compared with the asymmetric mode for the 135°–11.7 Nl/min case; this will be favorable to control the cleanliness of the molten steel. Additionally, analysis of both liquid-level fluctuations and turbulent-kinetic-energy distributions further confirmed the advantages of the symmetric gas-blown mode for suppressing slag entrapment. [ABSTRACT FROM AUTHOR]