3-D FEA of Cryogenic System for Cord Blood Banking

Abstract

Currently, umbilical cord blood stem cells are used in the treatment of over 40 life-threatening diseases, and play an important role in the treatment of blood and immune system related genetic diseases, cancers and blood disorders. Furthermore, in laboratory experiments it has been shown that cord blood stem cells can differentiate into a number of different cell types, which could give rise to future potential new therapeutic uses. Cord blood units are kept in cryogenic vessels filled with liquid nitrogen at -196°C. And in order to have cord blood cells available for potential future using, banks which store umbilical cord blood for future use have been created worldwide. This thesis is about a study of design an optimal cryogenic system for cord blood banking. 3-D (three-dimensional) models are employed and FEA (finite element method analysis) is used to do structure analyses of all designed models. First, each effect factor that related with structure strength will be analyzed using FEM (finite element method); and them, all models will be analyzed. Through doing FEA of structure to these six designed models, model 4 has been found out as an optimal design. It is not only light but also met the structure requirements well. And in order to improve the safety of the system, an active cooler has been designed after numerical heat transfer analysis. It can move heat that leaked into the vessel out actively, by this way, the active cooler can prevent the cryogenic vessel form pressure collapse, and also reduce the evaporation rate of liquid nitrogen in the tank. One of the biggest meanings of this thesis is that the numerical modeling and simulation with FEM can be used in the design of these systems to obtain good predictions of trends over a wide range of design alternatives and operating conditions.