Study On Heat Transfer Conductivity Of Subcooled Heat Exchanger In High Temperature Superconducting Motor Of Cooling System

With the adventure of the high temperature superconducting (HTS) materials, the temperature area of the superconducting technology application rises from the liquid helium area to the liquid nitrogen. HTS motors as a superconducting technology application get much attention from scientific research institutes all over the world. Compared with traditional motors, HTS motors have higher efficiency , smaller volume and lighter quality. So, HTS motors has great application market, and they will also be one of the most important scientific research in the 21st century.This paper is based on the cooperation project between institute of electromagnetic and electronic and institute of cryogenic and superconducting technology of Harbin industrial university. Its topic is an axis-radial flux high-temperature fully superconducting low speed synchronous motor. By researching the properties of different cryogenic working mediums and cryogenic engineering materials, we can choose the right ones for the HTS motor. Then we give out the heat load of the HTS motor and the state parameters of the whole liquid nitrogen circle. At last ,we draw the temperature-entropy graph.First, this paper give out the method of heat exchanging coefficients of cold head exchanger and subcooled exchanger of the coil heat exchanger, and then calculates the heat exchanging area according to the heat load.In addition to tube heat changer, we also give out the method of heat exchanging coefficients of cold head exchanger and subcooled exchanger ,and the calculate the area of them. By the Fluent simulation analysis of the tube heat exchanger , we compare the outlet temperature of the tube heat exchanger and that of coil heat exchanger.