| 论文简介 |
In this paper, two-phase flow instability in natural circulation loops of China Advanced
Research Reactor (CARR) has been investigated. CARR is a low pressure and low power
density research reactor. A natural circulation instability analysis model is developed for the
natural circulation loop of CARR. The homogeneous flow model is used to establish the
system control equations. The non-uniform heating and subcooled boiling heat transfer is
included. The accumulation heat of the wall is also included. Numerical method of Gear
is employed to solve the system equations documented in terms of ordinary differential equations.
According to the calculation results, stability maps of the natural circulation loop,
which confirm the presence of an instability region under the conditions of low equilibrium
quality in the outlet and low pressure, are obtained. It is a special kind of density wave oscillation
(DWO) that occurs in very low equilibrium quality region with the characteristics of
geysering and Type-I DWO at the same time. The calculation results show such oscillation
course clearly. The variations of the mass flow rate, the pressure drop and the boiling
boundary are analyzed separately. Especially, the phase-space trajectory of the boiling
boundary and the mass flow rate is discussed. Finally the oscillation frequency is discussed. |
(创新港)
