The dissertation describes the development of an integrated nuclear electromagnetic pump for the liquid metal cooled microreactor. The characteristics of the design variables around ALIP, which provide the optimized geometrical and electromagnetic parameters of the integrated nuclear electromagnetic pump, are analyzed. The Integrated Electromagnetic Nuclear Pump is designed to double the thermal output of the Small Modular Eutectic Fast Cooled Bismuth Lead Reactor (SMLFR) from 30 MWt to 60 MWt.
Introduction
In the introductory part, the electromagnetic and geometric design variables of ALIP are discussed. Detailed ALIP design specifications including developed pressure and efficiency were formulated based on the relevant equations. As part of the program, a conceptual design of an integrated nuclear electromagnetic pump was developed.
Literature survey
Electromagnetic pump development history
The first experimental electromagnetic pumps with alternating current conduction were developed in 1948 and electromagnetic pumps for transporting aluminum were used commercially by Ajax Engineering Company. In addition, the development of induction electromagnetic pumps was initiated and in 1950, 400 gpm (gallons per minute) spiral linear induction electromagnetic pumps and 1200 gpm (gallons per minute) planar linear induction electromagnetic pumps (FLIPs) were developed and tested. To solve this problem, many studies were conducted. carried out using permanent magnets to increase their efficiency, forming strong magnetic fields or by driving thermoelectric electromagnetic pumps in combination with thermoelectric generators [14–15].
Types of electromagnetic pump
Subsequently, various technologies such as moving magnet electromagnetic pump, spiral linear induction electromagnetic pump, ALIP, FLIP and thermoelectric electromagnetic pump (TEMP) have been developed based on the need and usage. In the case of FLIP, a transverse edge effect, caused by the geometric structure, is noticed; however, in the case of the ALIP, the electromagnetic core material is placed on the periphery, and the reduction in the performance is relatively small [24]. For this reason, the focus is on the analysis of the ALIP, which is more highly valued in the large flow rate liquid metal thermofluidic environments [25].
State-of-the-art in international and domestic technology
- International status
- Domestic status
A package of research and development activities was carried out to validate the operation of the electromagnetic pump for the cold trap. ANSYS FLUENT software was used in the numerical analysis of the effects of vibration on liquid metal flow. The amplitude of the vibrations was measured with a vibration instrument directly connected to the flow path of the electromagnetic pump.
Methods
Basic principles of electromagnetic pump
- Conduction electromagnetic pump
- Induction electromagnetic pump
Development and analysis of electromagnetic pump design program
- Development
- P-Q characteristics analysis with change in electrical input
- Evaluation of the design program
What is the size and power of the electromagnetic pump (a small conduction electromagnetic pump for a laboratory or a large induction electromagnetic pump in a nuclear reactor). In addition, the analysis of the characteristics such as the developed pressure and flow rate of the electromagnetic pump is carried out using the electromagnetic pump design program [72-75]. However, in the case of electrical equivalent circuit analysis, there is a partial simplification of the pressure relationship equation developed.
In this case, the equation for the pressure developed by the electromagnetic pump is calculated as shown in equation (3.2.5), which corresponds to equation (3.1.13). This is applied to the magnetic reactance of the developed pressure ratio in the ALIP design program. Therefore, it is necessary to consider additional pressure losses in the developed pressure equation for the electromagnetic pump.
In other words, a characteristic analysis is performed of the developed pressure and flow rate of the electromagnetic pump only (i.e. excluding the loop). Therefore, it is important to reduce the error in the results by taking into account the major and minor losses when performing an analysis of the developed pressure and flow rate of an electromagnetic pump. Developed pressure and flow rate characteristics of the ALIP corresponding to changes in input power (600 °C, 60 Hz).
Developed pressure and flow rate characteristics of center return type spiral induction electromagnetic pump under different frequencies (input voltage: 160 V). Developed pressure and flow rate characteristics of centerless-return type helical induction electromagnetic pump under different frequencies (input voltage: 140 V). The developed pressure and flow rate characteristic distributions were compared at 200 and 600 °C by entering the design specifications of the IA 501 model into the electromagnetic pump design program.
Design of the integrated nuclear electromagnetic pump
- Conceptual design
- Analysis
The stator coils are connected to a three-phase power supply to create a magnetic field along the length of the coolant channel. Consequently, the LBE coolant is transported by the Lorentz force generated in the passage of the vector product of the electric current and the magnetic field (J×B). The current in the current gap is induced by Faraday's law in the circumferential direction from the sinusoidal time-varying magnetic field of the axial direction in the inner core.
Consequently, the electromagnetic force in the axial direction of the electromagnetic pump is produced from the vector product of the induced current in the circumferential direction and the magnetic field in the radial direction perpendicular to it. The normal component of the magnetic flux density in Equation (3.3.17) is continuous at the interface between different media. Equation (3.3.18) indicates that the tangential component of the magnetic field intensity is continuous at the interface between the two media.
The magnetic permeability of the material used in the B/H electromagnetic pump is shown in Figure 3.3.4. The design variables of the electromagnetic pump integrated in the reactor can be optimized based on the analysis of the developed pressure and the input flow. The properties of the materials used in the design of the electromagnetic pump integrated into the reactor are summarized in table 3.3.2.
In addition, the electromagnetic characteristics of the reactor-integrated electromagnetic pump were analyzed using a commercial software ANSYS Maxwell.
Results and discussion
Design optimization analysis of the electromagnetic pump
- Design variables of the small electromagnetic pump
- Design variables analysis of the large electromagnetic pump
Estimation of the performance and measurement of electromagnetic field
- Fabrication of the electromagnetic pump and test bed
- Comparison of performance results between the experiments and program
The experimental loop was designed and constructed as shown in the figures for testing the preliminary characteristics of the ALIP. In that case, the amount of distorted magnetic field was reduced, causing a decrease or elimination of the Lorenz electromagnetic force in the reverse direction. The theoretical and experimental values of Lorenz electromagnetic force distribution around the ALIP were compared and analyzed, as shown in the figures.
The theoretical calculation confirmed that the electromagnetic Lorentz force was about 30% stronger near the tooth of the outer core due to an increase in the local magnetic field. However, the magnitude of the Lorentz force near the tooth of the outer core did not appear clearly through the experimental measurement results. The distortion of the magnetic field near both ends of ALIP caused a significant decrease in the electromagnetic Lorentz force, especially near the entrance.
With the final effect of the ALIP, a theoretical and experimental comparative analysis of the magnetic field strength was carried out and summarized as shown in the figures. It can be confirmed that the magnetic field strength of the internal current path of the ALIP was 50%. In addition, within the range of the magnetic field, not exceeding 0.02 T outside the input and output, the error was about 8% or less.
Therefore, it is possible to verify that the reduction and distortion of the magnetic field outside the entrance to ALIP was caused by the magnetic field distortion in the experimental and theoretical calculations.
Development of the integrated nuclear electromagnetic pump
- Design variables
- Performance and electromagnetic field analyses
It can be explained that too small an internal core diameter would cause a saturation of the magnetic flux in the core. The developed pressure and efficiency at 0.007 m from the opening had the maximum value in Figure 4.3.3. The design specifications of the small integrated nuclear electromagnetic pump model for characteristic analysis are summarized in Table 4.3.2.
Specifications of the small integrated nuclear electromagnetic pump model Design variable Unit value Design variable Unit value. Radial component of the magnetic field distribution along the electromagnetic pump as a function of time. The lines in Figure 4.3.8 represent the Lorentz force distributions of the integrated nuclear electromagnetic pump model with two, three and four pole pairs, and the corresponding average Lorentz forces were found to be 3146 N/m3 respectively for the same input power.
In Figure 4.3.9, the lines show the Lorentz force distributions of the integrated nuclear electromagnetic pump model, when the current gap width was about 45.6 mm and the corresponding average Lorentz force was 2497 N/m3, respectively. for the same input power. Therefore, reducing the coolant passage width obviously increased the efficiency of the integrated nuclear electromagnetic pump model. From an analysis of the design variables of the coolant circulation system, the design specifications and conceptual design of the integrated nuclear electromagnetic pump for the SMLFR, which is necessary to transport larger quantities of LBE coolant, were selected. These are shown in Table 4.3.3 and Figure 4.3.10. .
The temperature range of 300 to 450 °C is acceptable for the safe operation of the integrated nuclear electromagnetic pump for the SMLFR, considering the structural materials used, such as silicon steel, SUS 316 and copper.
Conclusions
34;Giant Electromagnetic Pump for Sodium Cooled Reactor Applications." IEEE International Electric Machines and Drives Conference, 2003. 34;MHD Design Analysis of a Linear Ring Induction Electromagnetic Pump for SFR Thermal Hydraulic Experimental Loop." Annals of Nuclear Energy. 34; Design Analysis of DC Electromagnetic Pump for Experimental Characterization of Liquid Sodium-CO2 Reaction.” Annals of Nuclear Energy.
34; Analyzes of Annular Linear Induction Pump Characteristics Using a Time-Harmonic Finite Difference Analysis." Nuclear Engineering and Technology. 34;Multiphysics Analysis of Liquid Metal Annular Linear Induction Pumps: A Project Overview." Proceedings of the Nuclear and Emerging Technologies for Space Conference 2016. 34;Two-dimensional model for analysis of cylindrical linear induction pump characteristics: model description and numerical analysis.” Energy Conversion and Management.
34;Dual Feed Frequency Pressure Pulsation in Annular Linear Induction Pump: Part I: Measurement and Numerical Analysis." Nuclear Engineering and Design. 34;Design Optimization Analysis of a Large Electromagnetic Pump for Sodium Refrigerant Transport in PGSFR." Annals of Nuclear Energy. 34; Performance Analysis of Magnetohydrodynamic Pump for Sodium-Cooled Fast Reactor Thermal Hydraulic Experiment.” Annals of Nuclear Energy.
34;Optimization of the outer core to reduce the end effect of the annular linear induction electromagnetic pump in the prototype sodium-cooled generation IV fast reactor.
