| Abstract |
In this work, we examine the questions of diagnostics
of heat-hydraulic systems of nuclear power stations with the
purpose of revealing of the oscillatory modes, which represent
danger to the equipment. On the basis of analogies between
hydraulic and electric processes, the electric models of elements
of hydraulic system are made. Heat-hydraulic systems are
simulated with the help of multi-circuit electric systems with
variable parameters. Nonlinear nature of real systems is taken
into account. During the research work it was determined that
oscillations have parametric nature. We examine three-contour
electric circuit with variable capacity. For the analysis of
oscillations the special programs realized in LabVIEW is
created. The threshold characteristic is received and the
conditions of stimulation of the parametrical oscillations arising
in multi-circuit models are determined. It is registered that the
parametric oscillations arise at the frequencies of capacity’s
variation close to heterodyne frequencies of the system (doubled
resonance frequencies, sum of resonance frequencies). The twocontour
nonlinear electric model of heat-hydraulic system is
worked out. We consider the mode of nonlinear restriction of
amplitude of oscillations. The special program in LabVIEW for
the analysis of the oscillations’ dynamic is created. The
frequency characteristics of multi-circuit systems are
constructed, and spectral structure of the oscillations is analyzed.
It is registered that the nonlinear nature of the system brings
positive effect to the appearing events. It reduces the probability
of damage of expensive equipment at power stations and
consequently reduces the probability of accident at nuclear
power plants. |
