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论文被International Journal of Heat and Mass Transfer接受


2016-07-19

         以第一作者发表学术论文“Investigatino on pressurization behaviors of two-side-insulated cryogenic tank during discharge"被工程热物理领域知名学术期刊International Journal of Heat and Mass Transfer接受。

        论文摘要如下:

Reducing pressurant gas requirement is of importance to the design of pressurization systems. In the

present paper, a two-side-insulated tank, in which both of interior and outside surfaces of the tank wall

are covered by insulation layers, is proposed, and a computational fluid dynamic (CFD) approach is

introduced to investigate its thermal behaviors and pressurization performance. The pressurant gas

requirement, temperature distributions, and energy distributions within the tank system are obtained

and analyzed. The results show that the inner insulation layer can remarkably reduce the gas requirement

during the liquid discharge period. For the event of pressuring a liquid oxygen (LO2) tank with

300 K helium gas, a decrease in gas requirement of 16% could be reached by using a 3-mm-thickness

foam layer at the tank interior surface. For the event of pressuring a liquid hydrogen (LH2) tank with

300 K hydrogen gas, the same thickness foam layer produces a decrease of 14.2% in gas requirement.

Moreover, the effect of inner insulation layer in reducing gas requirement is more significant with the

increase of inlet gas temperature. When 600 K helium gas is used to pressure the LO2 tank, a decrease

of 23.2% in gas requirement is reached by only a 1-mm-thickness foam layer in comparison with the tank

without inner layer. The effect of inner insulation layer in reducing gas requirement is mainly because the

energy distribution, occupied by ullage, wall, inner insulation layer and liquid propellant, is changed.

Since the character of low thermal conductivity for the insulation material, there is a significant temperature

drop within the insulation layer by which the heat transfer from ullage to insulation layer is

reduced apparently, resulting in more energy left in ullage to provide pressurization effect. However,

the gas-to-liquid heat transfer is also enhanced due to the warmer ullage caused by the introduction

of inner insulation layer, which suppresses the energy proportion rise in the ullage region. In general,

the introduction of inner insulation layer can distinctly reduce the pressurant gas requirement in the

pressurized discharge process of cryogenic tanks, and the two-side-insulated tank technique may be

an alternative technique in the design of pressurization system.