https://orcid.org/0000-0002-0689-3546
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Abstract
A submersible annular linear induction pump (ALIP) design with an outer diameter of 66.8 mm with appropriate materials is developed for circulating molten lead and alkali liquid metals of sodium and sodium-potassium-78 (NaK-78) alloy in test loops at temperatures up to 500°C. These loops investigate the compatibility of these liquid coolants with nuclear fuel and structure materials to support the development of advanced, Generation IV nuclear reactors. The present ALIP, which employs high-temperature ceramic-insulated coil wires and Hiperco-50 center core and stators, fits in Type 316 stainless steel, 2.5-in. standard schedule 5 pipe. This pipe, considered for the riser tube of the Versatile Test Reactor (VTR) in-pile test cartridge loop, has an inner diameter of 68.8 mm permitting 1.0-mm radial clearance for the present ALIP. An improved equivalent circuit model (ECM) is developed to analyze the performance of the present ALIP design. The accuracy of the model predictions is successfully validated using reported experimental measurements by other investigators for a low liquid sodium flow ALIP at 200°C and 330°C. The improved ECM calculates the performance characteristics of the present ALIP design and investigates the effects of varying the terminal voltage, current frequency, winding wire diameter, center core length, width of the liquid flow annulus, and working fluid properties and temperature on the pump operation. For circulating molten lead, the calculated peak efficiency of the present ALIP design of 6.7% occurs at a flow rate of 9.5 kg/s and pumping pressure of 263 kPa. The calculated peak efficiency for circulating liquid sodium is much higher, 26.3%, and occurs at a lower flow rate of 2.2 kg/s but a higher pumping pressure of 364 kPa. The calculated peak efficiency for circulating NaK-78 (23%) is lower than for sodium and occurs at a lower flow rate and pumping pressure of 1.9 kg/s and 310 kPa, respectively.
Acronyms
| AC: | = | alternating current |
| ALIP: | = | annular linear induction pump |
| AWG: | = | American Wire Gauge |
| ECM: | = | equivalent circuit model |
| FBR: | = | Fast Breeder Reactor |
| GEN-IV: | = | Generation IV |
| NaK-78: | = | sodium and sodium-potassium-78 |
| VAC: | = | volts alternating current |
| VTR: | = | Versatile Test Reactor |
| 316 SS: | = | Type 316 stainless steel |
Nomenclature
| = | = cross-section area of flow annulus (m2) | |
| = | = ratio of inner to outer annular flow channel diameters | |
| = | = cross-section area of winding conductor (m) | |
| = | = induced magnetic field flux density (T) | |
| = | = radial magnetic field flux density (T) | |
| = | = saturation magnetic field flux density (T) | |
| = | = mean diameter of flow annulus (m) | |
| = | = equivalent hydraulic diameter (m) | |
| = | = inner diameter of inner duct wall = center core diameter (m) | |
| = | = ALIP outer diameter (m) | |
| = | = inner diameter of outer duct wall (m) | |
| = | = stator inner diameter (m) | |
| = | = air gap induced voltage (V) | |
| = | = pump terminal voltage (V) | |
| = | = Lorentz force (N) | |
| = | = electrical current frequency (Hz) | |
| = | = friction factor | |
| = | = electrical current (A) | |
| = | = induced electric current (A) | |
| = | = induced electric current in the nonmagnetic gap (A) | |
| = | = phase electrical current (A) | |
| = | = winding distribution factor | |
| = | = multiplier factor for nonmagnetic gap width | |
| = | = pitch factor | |
| = | = Inductance (H); ALIP total length (m) | |
| = | = length (m) | |
| = | = extension length of ALIP center core (m) | |
| = | = length of pumping region (m) | |
| = | = average length of coil turns (m) | |
| = | = mass flow rate of working fluid (kg/s) | |
| = | = number of coils per phase in stator | |
| = | = number of poles | |
| = | = number of windings turns per coil | |
| = | = number of winding turns per phase | |
| = | = number of winding wires connected in parallel per phase | |
| = | = power (W) | |
| = | = dissipated thermal power (W) | |
| = | = electrical input power (W) | |
| = | = power factor | |
| = | = pumping power (W) | |
| = | = peak pumping power (W) | |
| = | = volumetric flow rate of working fluid (m3/s) | |
| = | = synchronous working fluid flow rate (m3/s) | |
| = | = Reynolds number, | |
| = | = electrical resistance of coil conductor per phase (Ω) | |
| = | = electrical resistance of flow duct inner wall (Ω) | |
| = | = electrical resistance of flow duct outer wall (Ω) | |
| = | = electrical resistance of working fluid (Ω) | |
| = | = reluctance (1/H) | |
| = | = slip ratio | |
| = | = stator slot width (m) | |
| = | = stator tooth width (m) | |
| = | = leakage reactance (Ω) | |
| = | = magnetizing reactance (Ω) |
Greek
| = | = net pumping pressure (Pa) | |
| = | = friction pressure losses (Pa) | |
| = | = developed pumping pressure from Lorentz force (Pa) | |
| = | = annular flow channel width (m) | |
| = | = coil height (m) | |
| = | = slot clearance height (m) | |
| = | = thickness of annular duct inner wall (m) | |
| = | = total nonmagnetic gap width (m) | |
| = | = thickness of annular duct outer wall (m) | |
| = | = stator back depth (m) | |
| = | = pump efficiency (%) | |
| = | = peak efficiency (%) | |
| = | = dynamic viscosity (Pa∙s) | |
| = | = permeability of free space (1.2567 × 10−6 H/m) | |
| = | = density (kg/m3) | |
| = | = electrical resistivity of winding conductor (Ω∙m) | |
| = | = electrical resistivity of annular duct walls (Ω∙m) | |
| = | = electrical resistivity of working fluid (Ω∙m) | |
| = | = pole pitch (m) | |
| = | = magnetic field (Wb) |
Acknowledgments
The authors acknowledge having access to the resources at The University of New Mexico’s Center for Advanced Research Computing, supported in part by the National Science Foundation.
Disclosure Statement
No potential conflict of interest is reported by the author(s).