The reasons why the submersible pump cannot run dry are as follows:
1. The general submersible pump cooling method is water-cooled. Whether it is internal water cooling, external water cooling or internal and external double water cooling, water is required as the medium to complete the cooling and heat dissipation work of the submersible pump. When the submersible pump is idling, there is no water to cool the heating parts such as the windings and bearings of the submersible pump, so the submersible pump is not allowed to run idling.
2. The cooling effect of the submersible pump's internal and external double water cooling is good. The inner cavity of the submersible pump is filled with water, and the stator core, stator winding, rotor core and rotor winding are all immersed in water, and are directly cooled by the water in the machine.
3. The heat generated by the iron loss of the motor stator, the resistance loss of the stator slot winding and the partial resistance loss of the end winding directly passes through the stator core, and is transferred to the cooling water flowing through the surface of the casing through the casing and taken away.
Part of the heat generated by the resistance loss of the rotor winding and the rotor iron loss is directly transferred to the stator through the air gap, and then transferred to the cooling water outside the motor through the stator, and the other part is transferred to the water in the rotor cavity. The internal winding is transmitted to the other part of the inner cavity filled with water, and the heat generated by the resistance loss and mechanical loss is transmitted to the stator core, casing and bearing seat through the inner cavity filled with water, and finally passes through the motor casing and bearing seat and other components. The surface is passed to the cooling water to take away.
