Design Of A Heat Exchanger And Its Reliability At Low Temperature

With the state’s support for the development of aerospace industry, there are increasing numbers of transonic wind tunnels that have been applied to civil or military in purpose. Because our country’ s heat-exchanger system in low Reynolds number field has fallen behind some developed countries which have the same industry development at least 30 years later, there are a lot of researches to improve many heat-exchangers’ manufacture technologies which have their special uses.The characteristics of low-temperature wind tunnel which will be designed is across the Maher number from less than 1 to more than 1, the airflow will transfer a great deal of heat in the test section. Once determining the core, we can conduct heat engineering calculation which involves total heat transfer area, total front face area, water-side pressure drop and heat capacity of water cooling system.The turbulent flow of water inside tubes or air outside tubes can able to create partial vibration phenomenon in heat exchanger. If you do not pay enough attention to analysis, it will cause the serious vibration damage eventually, lower efficiency of heat-exchanger, and even the occurrence of leakage. Therefore, according to the former design and structure of the heat exchanger, we would theoretically calculate the dynamic characteristics and the inherent frequency among the heat-exchanger’s tubes and research the vibration mechanism for vibration protection.The design and structure of the heat-exchanger not only need to be meet the heat transfer from each other under normal temperature condition, but also to be placed in the ultralow temperature (about 90K), and it could be called the extremely harsh condition, withstanding the ultralow temperature cold environment. So we emphasize the connection and the welding between fins and tubes to verify that there will be no influence on the solder joint strength under the low temperature.