Pressure control methods for a pressurized cooling system with repetitive cycles of transient dynamic behavior.

摘要

Pressurizer (PZR) behavior in typical pressurized water reactor (PWR) nuclear power plants is well understood. Pressure control is relatively straightforward for a typical PWR, since the larger fluid system normally operates in a very steady state condition. However, pressure control is more complicated for a pressurizer in a pulsed cooling system, such as the cooling system for a tokamak fusion reactor. During normal operation the tokamak's plasma is pulsed, instead of staying at a constant value, which results in temperature swings between the plasma pulses. This design characteristic means that (a) coolant temperatures fluctuate over a larger range during normal operation than typical PWRs experience and (b) fluid volume also varies as the coolant temperature changes, since fluid (water) density is a function of temperature.;Pressurizer pressure control is typically accomplished with an on/off and proportional control strategy in PWRs. However, this approach alone may not meet the desired control performance for a pulsed cooling system. Therefore, a dynamic model based control design approach is proposed that permits modification online as the process dynamics change by uniquely combining a hybrid control technique with a method to improve system knowledge. This research includes contributions to PZR control modeling, dynamic simulation inputs, adaptive-optimal and adaptive-dynamic control, and system knowledge. Simulations support that this approach enables greater control of the process during transients than is achievable with a conventional control approach.