Flow Resistance Modeling for Coolant Distribution within Canned Motor Cooling Loops

Abstract

Taylor-Couette-Poiseuille (TCP) flow dominates the inner water-cooling circulation of canned motor reactor coolant pumps. Current research on TCP flow focuses on torque behaviors and flow regime transitions through experiments and simulations. However, research on axial flow resistance in a large Reynolds number turbulent state is not sufficient, especially for the various flow patterns. This study is devoted to investigating the influence of annular flow on the axial flow resistance of liquid in the coaxial cylinders of the stator and rotor in canned motor reactor coolant pumps, and predicting the coolant flow distribution between the upper coil cooling loop and lower bearing lubricating loop for safe operation. The axial flow resistance, coupled with the annular rotation, is experimentally investigated at a flow rate with an axial Reynolds number, Re a , from 2.6 × 10 3 to 6.0 × 10 3 and rotational Reynolds number, Re t , from 1.6 × 10 4 to 4.0 × 10 4. It is revealed that the axial flow frictional coefficient varies against the axial flow rate in linear relation sets with logarithmic coordinates, which shift up when the flow has a higher Re t. Further examination of the axial flow resistance, with the Re a extending to 3.5 × 10 5 and Re t up to 1.6 × 10 5 , by simulation shows gentle variation rates in the axial flow frictional coefficients against the Re a. The relation curves with different Re t values converge when the Re a exceeds 3.5 × 10 5. A prediction model for TCP flow consisting of a polygonal approximation with logarithmic coordinates is developed to estimate the axial flow resistance against different axial and rotational Reynolds numbers for the evaluation of heat and mass transfer during transition states and the engineering design of the canned motor chamber structure.

Numerical simulation of heat dissipation of surface mounted permanent magnet synchronous hub motor

“…There are mainly two ways: one is to directly select insulating materials with high thermal conductivity, or to fill the insulating materials with better thermal conductivity. The other is to control the insulation treatment process, try to eliminate the gaps in the insulation layer, and improve the compactness of the insulation layer [12]. On the basis of the above calculation results, the numerical simulation experiments are designed as follows [13].…”

Experimental study on the internal temperature rise of a high-speed canned motor pump for liquid rocket engines

“…With the rotor immersed in the operating medium, additional water friction loss occurs and leads to temperature rise of the partial flow that passes through the air-gap. Although this issue has been studied in the field of reactor coolant pumps and oil & gas pumps, however, these pumps generally operate at speeds below 3000 r/min [11][12][13][14]. As the speed comes to over 30000 r/min in propellant pumps for rocket engines, the water friction loss increases intensely and makes the major loss of the canned motor.…”