Experimental Research On Subcooler Of Charging System Of Liquified Oxygen

Liquefied oxygen is the essential component of propellant for carrier rocket and spacecraft, which usually stays in saturated condition. In the charging process, it is very easy for liquefied oxygen to become two phase flow, which will lead to the failure of charging process. Moreover, liquefied oxygen is apt to evaporate before launch, which will decrease the liquid volume in the tank of rocket, prolong the charging process and make charging times increase.Overcooled liquefied oxygen is a key to issues above, and overcooling charging plays an important role in preventing two phase flow and evaporation loss of liquefied oxygen.This paper analyzes characteristic of liquefied oxygen while been adopted as propellant in the process of charging and storage, and does researches and design on the methods to overcool liquefied oxygen. Experiments are carried out to research the heat transfer proprieties in the overcooling process on two ways, first of which is cooled by boiling of liquefied nitrogen under normal pressure, and the other is under sub-atmospheric pressure. Heat exchange process between liquefied oxygen and liquefied nitrogen is analyzed, and outcome by different boiling style of liquefied nitrogen are compared.According to the different boiling style, boiling heat transfer coefficient equations for each style are searched out, and theoretical design process is summarized, in which parameters and their influence to the outcome of overcooling process when change are analyzed. Moreover, other methods of overcooling are briefly introduced.Based on the conclusion of theoretical analysis, three type of heat exchanger are chosen for further experimental research, they are spiral tube, double tube and shell tube heat exchanger. Different layout and configuration are designed according to the boiling style of liquefied nitrogen, and the outcome of overcooling process is record and analyzed. Theoretic design method are verified after comparing the experimental outcome of overcooled liquefied oxygen.Analyze a practical project and provide some solution.