Search

The large-scale training of artificial intelligence （AI） has led to a significant surge in computational resource demands， energy consumption， and carbon emissions， which not only poses severe challenges to the realization of carbon peaking and neutrality goals by AI technology itself， but also impedes the application of AI in edge devices such as power inspection robots and UAVs. During the digital transformation of power grids under carbon peaking and neutrality goals， study of green AI for energy saving and carbon reduction is of great significance to the construction of new power systems and the advancement of AI. Firstly， the origin and definition of green AI and the key factors affecting the energy consumption of the model are introduced； then the current development status， key issues， improvement methods and effects of green AI model technology are discussed. Afterwards， the energy-saving and carbon reduction measures of high-efficiency physical infrastructures are discussed. Finally， the relevant suggestions and outlooks for the future development of green AI are presented.

BackgroundWith the development of human aerospace industry, it is necessary to develop propulsion systems suitable for different space mission scenarios. MegnetoPlasmaDynamic thruster (MPDT), which is similar to the principle of magnetic confinement fusion, is a typical representative of electromagnetic thruster, which stands out among many electric thrusters because of its superior performance in thrust power ratio and specific impulse. Anode power deposition is the result of the interaction between plasma and wall during MPDT operation. It is one of the main mechanisms of power loss of this type of thruster, accounting for 40%~90% of the total power, which seriously reduces the efficiency of thruster.PurposeThis study aims to solve the problem of low efficiency of thruster by investigating the influence of anode radius on the efficiency of thruster from the perspective of anode power deposition.MethodsFirst of all, based on MagnetoHydroDynamic (MHD) equations, numerical models for radial discharge parameters and physical model for anode power deposition were established. Then, the influences of anode radius on discharge parameters, anode power deposition and anode power deposition fraction were studied on the basis of these models by numerical calculation method. Finally, a water-cooled structure anode was designed, and the effectiveness of its heat dissipation structure was verified by thermal simulation.ResultsThe results show that with the increase of anode radius, the electron density and ion velocity are increased, the anode power deposition fraction is decreased whilst the anode power deposition is increased. The thruster efficiency is improved by increasing the anode radius. The thermal simulation results show that when the input power deposition of the water-cooled structure anode is about 3 kW, the corresponding temperature difference of the anode cooling water is 5 K.ConclusionsThis study verifies the reliability of the physical model of anode power deposition, indicating that increasing the anode radius is an effective means to improve the efficiency of the thruster.

BackgroundElectric propulsion systems, compared to traditional chemical propulsion, offer longer operational lifespans and lower fuel consumption in space missions, garnering significant attention in recent years. However, for high-power Hall effect electric thrusters developed based on controlled fusion concepts, measuring thrust proves challenging due to the high-temperature environments required for ionizing propellants in electric thruster, resulting in the generation of hot plasma plumes during operation. As a result, traditional thrust measurement methods are unable to accurately measure the thrust.PurposeThis study aims to accurately measure thrust during ground testing of electric thrusters for precise control of the spacecraft's attitude and orbit maintenance.MethodsFirstly, a thrust measurement platform based on flexible beam structure was designed and implemented with capability of measuring the thrust generated by electric thrusters in high-temperature. Simultaneously, a calibration system was built to verify the stability and repeatability of the thrust measurement results. Then, simulation analysis was conducted on the structural mechanics and thermal coupling field of the thrust measurement system under different operating conditions. Finally, the variable specific impulse magnetoplasma rocket (VASIMR) was taken for experimental thrust measurement of its electric propulsion system.ResultsThe experimental results of VASIMR indicate the thrust is 266.5 mN measured in real time at the central magnetic field intensity of 0.2 T with a mass flow rate of 20 mg∙s-1.ConclusionsThe thrust measurement platform based on the bending beam structure can meet the measurement requirements of VASIMR, providing valuable references for subsequent experiments.

BackgroundFusion reactor engineering models are extremely complex, which makes the modeling of the neutronics analysis rather tedious and time consuming. The open-source Monte Carlo code OpenMC can directly perform particle transport simulation on CAD models by integrating DAGMC (Direct Accelerated Geometry Monte Carlo), which can significantly improve the modeling and analysis efficiency of complex engineering models.PurposeThis study aims to carry out the application research of OpenMC in fusion neutronics analysis for China Fusion Engineering Test Reactor (CFETR).MethodsBased on the CFETR 1D cylindrical shell model, the consistency of tallies of OpenMC and MCNP was verified. According to the characteristics of plasma spatial distribution, source class and source function were customized on base of the source extension interface to accurately describe the complex fusion neutron source. The 3D model of complex CFETR engineering was successfully established by using CAD geometry function of DAG-OpenMC, and the neutron wall load distribution, tritium breeding ratio (TBR) and heat were obtained.ResultsThe calculation results of DAG-OpenMC and MCNP have excellent consistency. The neutron wall load peak of CFETR appears at the mid plane, and the tritium breeding ratio of helium cooled ceramic breeder blanket is 1.141. When the fusion neutron power is 160 MW, the total nuclear heat generated is 211.73 MW, and the global energy multiplication factor is 1.32, in which the total nuclear heat generated by the blanket is 185.64 MW, accounting for 87.68% of the total nuclear heat.ConclusionsThe CAD-based geometry capabilities greatly improve the modeling efficiency of building complex fusion reactor engineering models. Verification of the key issues of DAG-OpenMC in fusion neutronics applications by this study, indicates its feasibility in dealing with fusion neutronics problems under complex engineering structural conditions.