Abstract:

In order to reveal the characteristics of the unsteady two-phase flow and heat transfer during the cryogenic pipe chilldown, literature investigation and comparative analysis are conducted to summarize the related research progress in this field. The main factors of the cryogenic pipe chilldown are investigated and classified, and the numerical results are studied. Moreover, the applicability of the existing flow boiling correlations to the cryogenic boiling process is discussed , and the related experimental research on the cryogenic pipe chilldown in the microgravity environment is summarized. Conclusions have been drawn as follows: 1) Compared with the typical flow boiling, the cryogenic chilldown boiling which can be reversely described by the typical boiling curve performs differently in the characteristics of the heat transfer and flow patterns; 2) The factors of the mass flow rate, the flow directions and the physical properties make an important influence on the mechanism and characteristics of the cryogenic pipe chilldown; 3) The traditional flow boiling heat transfer correlations can not apply to the heat transfer studies during the cryogenic chilldown boiling, and it should be paid more attention to developing new correlations to predict the pipe chilldown process. Based on the theoretical research and experimental progress of the cryogenic chilldown boiling, a suggestive research is proposed to provide the reference and theoretical basis for the safe and efficient filling of the cryogenic propellant.

Key words: Cryogenic propellant, Pipe chilldown, Boiling heat transfer, Correlations of boiling, Review