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RSS2022 Vol. 9, No. 2
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2022, 9(2): 1-1.
Abstract:
2022, 9(2): 1-18.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.001
Abstract:
Introduction Tokamak is recognized as the most feasible program for fusion power source, however various physical and engineering technology problems should be overcome before being power source. Error field, as inevitable non-axisymmetric perturbation magnetic field, can induce locked mode and degrade plasma stored energy, and further degrade the fusion reaction rate, or even resulting in disruption and damaging first wall of the device, threatening the safety and economy of fusion reactors. Therefore, it has been considered to be one of the most concerned problems in tokamaks over 30 years. Method To clarify the progress of error field investigation, we reviewed the history of error field investigation, summarized the research achievements over 40 years from the aspects of experiment, theoretical analysis and numerical simulation. Result On the basis of error field progress, we list the most concerned and unresolved problems in error field investigation in the world. Conclusion We expect that this paper will provide some guidance for further investigations on frontier problems of error field, and help to contribute our strength to the knowledge of magnetically confined fusion physics.
2022, 9(2): 19-25.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.002
Abstract:
Introduction In order to realize controlled nuclear fusion and solve the future energy problems of mankind, International Thermonuclear Experimental Reactor (ITER) is planning to build a superconducting tokamak device for fusion reaction. Method This paper briefly described the significance and development of ITER program and introduced the composition and function of its power supply system, as well as the structure and technical parameters of converter power supply of main coils. Result Finally, the optimization design of ITER magnet power supply in China and related procurement task for magnet power supply that have been completed are proposed. Conclusion By participating in ITER research projects, China has made important contributions to the development of international fusion engineering technology.
2022, 9(2): 26-32.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.003
Abstract:
Introduction To ensure the safe and stable operation of the equipment, the power electronic equipment regulated by the International Thermonuclear Experimental Reactor (ITER) organization must pass the relevant magnetic field immunity test. Method Based on ITER requirements, the parameter requirements of the required test system were defined. Square solenoid coil and square three coil were selected as the research objects. The structural parameters of the optimal performance were calculated by numerical calculation method, and the correctness of the calculation was verified by finite element method. Result Compared with the two coil types, the solenoid with low power consumption is selected as the final structure. Then, based on this parameter, the power topology of DC transient is analyzed, the relevant parameters are calculated, and the performance data required by the final power supply is determined. Conclusion The research of this paper provides a detailed calculation process and design reference for the design of induction coil and its power supply of ITER high-power magnetic field immunity test system.
2022, 9(2): 33-38.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.004
Abstract:
Introduction The huge energy stored in the superconducting magnet in quench state is transferred and consumed by China Fusion Engineering Experimental Reactor (CFETR) quench protection system to prevent it from damage. In order to meet the design requirements of CFETR quench protection system, the overall design of the system is carried out in this paper. Method The basic principle and action logic of quench protection system were introduced, and the system design parameters of toroidal field coil (TF) quench protection unit and poloidal field / central solenoid coil (PF/CS) quench protection unit were described respectively. Result The two different schemes currently designed are analyzed. The topological structure and the switching logic of the quench protection switch, and the design requirements of other components are mainly introduced. Conclusion For the overall design scheme of the system, due to low cost, less land occupation, relatively mature technology and high feasibility, the mechanical DC switch with artificial current zero-crossing is the preferred scheme. Taking into account good prospects for development, hybrid DC switch with mechanical switch and solid-state switch is chosen as alternative.
2022, 9(2): 39-44.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.005
Abstract:
Introduction China Fusion Engineering Experimental Reactror （CFETR） aims to demonstrate the engineering feasibility of steady-state combustion plasma. The 110 kV high-voltage power supply and distribution system supplies the superconducting magnet and the reactive power system through cables and other equipment. Therefore, the stable work of the high-voltage cable is very important to the development of the experiment. Method The normal operation of the cable needed to consider the induced potential and circulating current of the metal sheath. In this paper, after fully investigating and calculating the metal sheathing method, it was determined that the 110 kV high-voltage XLPE cable was cross-connected and grounded. Use ANSYS Maxwell to model the three-phase cable, simulate the sheath induced voltage, and finally substitute the simulation results into the equivalent circuit constructed by Simplorer. Result The simulation results show that the induced electric potential and circulating current of the sheath meet the requirements of national standards. Conclusion The cross interconnection grounding scheme designed in this paper for the 110 kV cable sheath is safe and reliable, which can ensure the long-term stable operation of the cable.
2022, 9(2): 45-52.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.006
Abstract:
Introduction Based on the power output characteristics of China Fusion Engineering Experimental Reactor(CFETR) and under the condition of the maximum thermal power 1.25 GW, this paper aims to provide a conceptual design scheme of CFETR fusion power plant. Method To resolve the confliction between the periodic long pulse output characteristics of CFETR fusion reactor and the continuous stable input requirements of conventional island equipment, the energy storage technology scheme was adopted to realize the safe and stable operation of CFETR fusion power generation in the way of “peak cutting and valley filling” .We discussed energy storage under two different cladding schemes of CFETR fusion water cooling and helium cooling, as well as the combination scheme of coupling and decoupling operation modes between primary and secondary circuits. Through scheme comparison, the optimal energy storage operation combination corresponding to different cladding of CFETR fusion reactor was given. Result The results show that the best combination scheme of water-cooled cladding and helium cooled cladding fusion reactor is heat transfer oil + decoupled heat storage scheme and molten salt + coupled heat storage scheme. Conclusion From the conventional island side, compared with the water-cooled cladding scheme, the technical economy of CFETR fusion power plant with the helium cooled cladding scheme is better. The conceptual design scheme of CFETR fusion power plant has high reference value for the subsequent fusion power generation technology research and engineering design.
2022, 9(2): 53-62.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.007
Abstract:
Introduction The power output of China Fusion Engineering Test Reactor (CFETR) is periodic, which can not directly meet the stable and continuous input requirements of conventional power generation equipment. CFETR fusion power plant needs to integrate a specific process system between nuclear island and conventional island. Method By investigating the application of concentrating solar power plants and the literature research of fusion power plants, this paper presented a discussion based on the preliminary performance of CFETR about the comparison between energy storage and energy supplement, energy storage techniques, thermal storage mediums and thermal storage system schemes. Result For fusion reactors with water-cooled blanket and helium cooled blanket, it is proposed to integrate an indirect double-tanks sensible thermal storage system with hydrogenated triphenyl heat transfer oil and solar salt molten salt as thermal storage medium respectively, so as to ensure the stable and continuous operation of the power generation system. Conclusion The proposed energy storage scheme meets the conditions of large-scale commercial applications and supports the overall design of CFETR fusion power plant.
2022, 9(2): 63-69.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.008
Abstract:
Introduction The general layout of the plant has great significance for the conceptual design process of the China Fusion Engineering Test Reactor (CFETR). Herein, preliminary exploration of the fusion power plant general layout has been conducted by comparing various energy storage system selection and planning energy storage area layout. Method This research analyzed the energy flow characters of the fusion power plant, energy storage technology route and the characteristics of heat storage materials. Techno-economic comparisons have also been given among four plans of various combination of heat storage methods and their layouts. Result We find that the molten salt storage solution has outstanding economic strengths, but its high temperature corrosion has a greater impact on the safety operation and maintenance of nuclear power plants, while the heat transfer oil solution is just the opposite. Therefore, the results show that triangular arrangement or tandem arrangement of energy storage areas with nuclear islands and conventional islands can well meet the thermal system of the whole plant and the thermal operation flow direction of the energy storage system, which is in line with the general layout requirements. Conclusion In conclusion, the energy storage technology route and the arrangement of the storage area are key factors affecting the layout of fusion power plants. The layout presented in this paper are all well adapted to the thermal operation of the newly added energy storage system that may be applied in the fusion power plant general layout.
2022, 9(2): 70-76.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.009
Abstract:
Introduction The paper aims to effectively suppress the disturbance of non characteristic harmonics to the power grid in the tokamak power supply system, the paper studies the mechanism of low-frequency harmonics in the tokamak power supply system. Method By introducing an improved switching function model, selected ITER fusion device as an example and established its corresponding AC/DC equivalent circuit model combined with its corresponding parameters, the corresponding output second harmonic was obtained through calculation and simulation. Result The ratio of output to input is calculated, and the stability factor value almost tends to zero. Conclusion It is determined that the DC bias of rectifier transformer do not cause harmonic instability of the system.
2022, 9(2): 77-81.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.010
Abstract:
Introduction In order to realize the real-time reconstruction of plasma shape and position in tokamak, a visible light edge reconstruction algorithm based on fully connected neural network is proposed based on the analysis of camera calibration algorithm. Method The function of the algorithm was to establish the corresponding relationship between the pixel coordinate system and the tokamak coordinate system, and then realize the plasma visible light edge reconstruction. Result On the basis of the algorithm, few-shot learning is added to further improve the reconstruction algorithm of fully connected neural network. Conclusion Experimental results show that the algorithm can accurately reconstruct the plasma visible light edge, and also meet the real-time requirements of the system.
2022, 9(2): 82-89.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.011
Abstract:
Introduction To evaluate the anti magnetic interference ability of electrical and electronic devices, it is necessary to carry out the corresponding magnetic field immunity test, in which the high uniformity steady-state magnetic field generator is the core component of a steady-state test device. Method Taking the conventional Helmholtz and Maxwell square coil as the research object, the parameters were optimized through numerical calculation, and the coil structure that can produce high-performance magnetic field was obtained analytically. The finite element method was used to establish a model for calculation, and the correctness of the results was verified. Result The general calculation formula of coil parameters is obtained through numerical analysis, and the two coil types are compared. The optimized Maxwell square coil with small size and power consumption is selected as the final structure. Conclusion The research of this paper provides a detailed calculation process and design reference for the high uniformity steady-state magnetic field generator, and can provide a theoretical basis for the design of corresponding equipment in the electrical industry.
2022, 9(2): 90-94.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.012
Abstract:
Introduction Using nuclear fusion to generate electricity is a promising way for nuclear energy in the future. In order to research the best civil structure design, it is necessary to discuss techniques from fossil fuel power plant and conventional island of other NPPs. Method Through comparation analysis, structure system of main building, roof structure, TG foundation and fire protection design were discussed. Result Conceptual design for civil structure and engineering advice are also given. Conclusion The research in this paper can provide reference for similar project.
2022, 9(2): 95-100.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.013
Abstract:
Introduction As an important design improvement to cope with the station black out (SBO) accident, the advanced secondary passive residual heat removal (ASP) system is based on the closed natural circulation of secondary side of the steam generator (SG), can effectively remove the residual heat of the reactor core in the case of total loss of feedwater. Method Based on full-scope simulator (FSS),the paper introduced the SBO superimposed SBO diesel engine failure and ASG pneumatic pump failure accident conditions on the simulator platform , and verified the influence of the ASP system for the primary and secondary loops of nuclear plants in accident conditions by using the simulation method. Result The simulation results we obtained demonstrate that after the ASP system was put into operation, the residual heat of the core was effectively removed. After 4 hours , the water level of the SG recover to 8.6 m, the pressure of the SG dropped to 1.2 MPa（a）, the core outlet temperature dropped to about 209 ℃, and the margin of core saturation temperature is greater than 20 ℃, there is no risk of meltdown of the core, and the accident is in a controllable state. Conclusion The ASP system meets the requirements of the design conditions, and can realize the long-term and effective removal of the residual heat of the reactor core.
2022, 9(2): 101-106.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.014
Abstract:
Introduction The RGL system (Rod Position Indication and Rod Control System) is one of the important control systems in nuclear power unit, its performance is directly related to the availability of nuclear power unit when the double-hold fault happen in the RGL system, the entire control rod group will be locked, and the control rods cannot move in time during the transient test, load reducing operation or load raising operation of the unit, which may lead to the shut down of the reactor. Method Based on the experience feedback of the double-hold fault of the RGL system in a CPR1000 unit, this paper analyzed and researched the cause of the double-hold fault from the perspective of design principles. Result The analysis results indicate that the moment controller in the controller software misjudges the state of the MG rack, and thus outputs the wrong signal, which leads to the triggering of the double-hold fault. Conclusion Software defect is an important factor causing double hold fault of RGL system.
2022, 9(2): 107-112.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.015
Abstract:
Introduction The pressure transmitter important to safety of nuclear power plant needs to pass the equipment qualification to confirm that it can perform the safety function under the accident condition. However, the current relevant standards do not explain the logic and mechanism of such equipment qualification, the rationality is not sufficient. Methods Based on the understanding of the identification system of electrical equipment important to safety at home and abroad, combined with the actual identification process of pressure transmitter important to safety of HPR1000, the identification theory of pressure transmitter important to safety was studied in detail. Results The important operating environment factors affecting its safety performance were analyzed, the significant aging mechanism was identified, the accelerated aging test was described based on the accelerated aging mathematical model, and the typical accelerated aging sequence and identification process of the safety-important pressure transmitter of HPR1000 was recommended. Conclusion The identification process can be used as a reference for the identification of safety-important pressure transmitters in China.
2022, 9(2): 113-119.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.016
Abstract:
Introduction With the promotion of the "going out" strategy of China's nuclear power industry, the ability of independent supply of nuclear power equipment is more important for export of NPP. Especially in the context of the current Sino-US trade friction, the localization of core equipment is more required. Method Based on the successful achievement of localization of RCP for an international NPP project exported by China, the route and method of localization of high-tech equipment was analyzed. Result As the most technically complicated main equipment of NI and also as export controlled dual-use item and replying on the rapid development of heavy equipment manufacturing in China, the localization of Reactor Coolant Pump (RCP) has been finally achieved for an international NPP project. Conclusion It broke down monopoly of the developed countries on supply of RCP, and solidified China's position as a great power of nuclear power equipment manufacturing. It also provided practical experience on design and production of high-tech equipment.
2022, 9(2): 120-124.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.017
Abstract:
Introduction The paper aims to research the technology feasibility of steam conversion system for industrial steam supply by pressurized water reactor (PWR) nuclear power. Method we took a 1 000 MW (PWR) nuclear power plant as an example, supplying industrial steam 300 t/h, 1.8 MPa and 250 ℃. This paper demonstrated the technical feasibility of a steam conversion system which could meet the industrial steam needs by using steam in the secondary loop of PWR nuclear power plant to heat industrial water, based on the first law and the second law of thermodynamics. This paper designed the process flow of the system, calculated the thermodynamic parameters of the key heat exchangers in the system. Result The reasonable value of the heat source drainage temperature was analyzed. Our data suggest heat source drainage temperature is 65 ℃ for the industrial steam supply of PWR nuclear power plants. The temperature of heat source would be lower than the industrial water if the drainage temperature was lower than 60 ℃ , which would violate the second law of thermodynamics. Conclusion The research results can provide technical reference for industrial steam supply of PWR nuclear power plant.
2022, 9(2): 125-130.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.018
Abstract:
Introduction The important value of equipment reliability data in nuclear power plant PSA, RCM, maintenance rules, reliability assurance program, risk guide management and other fields, puts forward the necessity of developing AP1000 equipment reliability database. Method Some important issues in the development process of AP1000 nuclear power plant specific database, such as independent failure analysis process, equipment and equipment category selection, reliability parameter estimation method, common cause failure analysis method and process, nuclear power plant specific data and general data. The collection and analysis of nuclear power plant specific data and general data collection and analysis, as well as the application of reliability data, etc. were discussed. Result The technical route for the development of AP1000 power plant specific equipment reliability database was proposed. Conclusion The establishment and application of AP1000 nuclear power plant equipment reliability database can accumulate valuable nuclear power plant specific operation, maintenance, failure, test and other data, provide reliability parameters for nuclear power plant operation PSA, provide an important reference for optimize operation and maintenance, safety management and other fields.
2022, 9(2): 131-136.
doi: 10.16516/j.gedi.issn2095-8676.2022.02.019
Abstract:
Introduction The paper aims to develop a corrosion resistant and wearable ultrahigh molecular weight polyethylene(UHMWPE) nozzle in order to solve the nozzle erosion and corrosion problems of circulating water filtration system(CFI) which is nuclear safety grade 3 system in nuclear power plant. Method Through the test of important processing parameters, the nozzle manufacturing process was confirmed. In order to verify the wear resistance and hydraulic performance of the developed nozzle, the wear resistance test of the material was carried out and the scour test and hydraulic test using developed nozzles also have been done. Result Test results demonstrate that the UHMWPE nozzle has excellent wear resistance, which is much better than traditional materials. The UHMWPE nozzle can meet the needs of high-speed erosion of nuclear power plants, and its hydraulic performance can also meet the requirements of nuclear power plants. Conclusion The test results show that the performance of the UHMWPE nozzle is excellent. It has been used in the nuclear power plant for one and a half years, after continuous operation, no scour deformation and corrosion phenomena were found. Therefore, it is feasible to use it in the CFI system of nuclear power plant, which can replace the original imported nylon nozzle.
