Design And Thermal Analysis For Heat Shield Of Vacuum Resistance Furnace

With the increasing requirements of the experiments, the use of vacuum resistance furnace is becoming more and more extensive. As an important component the heat shield plays a momentous role in the vacuum resistance furnace. The insulation efficiency of the heat shield will affect the temperature of the vacuum resistance furnace both inside and outside and also have influence on the overall performance of the vacuum furnace. Therefore, it is necessary to make an analysis of the heat shield of the vacuum resistance furnace and make thermal analytical investigation.Based on the theory of heat transfer, it deduced the radiative transfer and the computing method of heat conduction and got the conclusion that the main heat exchanger in a vacuum resistance furnace is thermal radiation. Based on the thermal radiation theory and the environmental requirement of the heat screen, it worked out at the temperature of the heat screens. Then it designed the theoretical model corresponded to experiment.After making up the theoretical model, it made analysis and confirmation on the theoretical model with finite-element analysis and got the following conclusions:1. It made analysis of the correlation theory and the account form of the heat transfer, and deduced the important parameters-the angle factor formula used to heat shield in the thermal analysis.2. It analyzed the radiative transfer of the heat shield and worked out the theoretical temperature of each layer screen when putting six layers of metal heat shield between the silicon carbide and water wall.3. Based on the calculated temperature of each layer, it first adopted to use a three-layer molybdenum screen with a combination of three layers of stainless steel heat shield.4. Using the model of the heat shield, make thermoanalysis of the adiative heat transfer in high temperature furnace with Ansys software and get the temperature cloud picture and graph of the heat screen under the temperature1000℃.At last, it tested and verified the preliminary scheme and confirmed the reasonable number of plies heat screen is five.