Синтез подоби електронної системи керування швидкодіючою редукційно-охолоджувальною установкою

Abstract

У статті розглянуто проблему швидкості реакції системи керування швидкодіючої редукційно-охолоджувальної установки пари у енергогенеруючій галузі і хімічній промисловості. Запропоновано стратегію керування процесом за випереджуючим прогнозом. В якості критерію запропоновано момент настання передвідмовного стану, який обчислюється порівнянням обчисленого за показаннями датчиків поточного значення повної енергії пари з його гранично припустимим значенням. Запропоновано варіант алгоритму системи керування.

The problem of quick-response steam flow reduction-cooling device control system used in energy branch and chemical industry is considered in the paper. The experience of last disasters with nuclear power plants and in chemical industry shows that the safety problem is still acute there and that the comparative rareness of such matters is balanced by severity of damages and number of casualties. The key factor which strongly limits any effort to upgrade safety is mechanical inertia of executive devices. The control system’s response time is the sole criteria, determining either disaster’s elimination or its increase. But just the system’s respond time remains in right dependence of executive devices’ masses as well total amounts of energy-carrying media, their temperature, pressure, flow rates, etc. As about quick-response reduction cooling devices (QRCD) the problem is multiplied by such a fact that consumers of steam prefabricated by the QRCD also need a lot of time for preparing in order to avoid their damage. It seems this problem has no resolving via traditional methods. Because all known algorithms embodied in practice act in post-factum mode. I.e. control system’s command signals are generated upon receiving alarm. So the principally novel approach is proposed in this paper both for QRCD control systems and other ones of similar purpose. Namely it is proposed to change reactive control system acting post-factum by active one based on advanced forecast. It includes involving of the term of prior-to-fail system’s state. The prior-to-fail time is proposed as criteria to realize control together with the term of full energy reserve. This algorithm envisages the foregoing definition of maximal allowed overheated steam flow parameters and full energy (per second) value calculated on a basis of them. While operating current parameters values are measured via sensors and current full energy figure is calculated together with its first and second derivatives. Time between current and maximal full energy (rate) values is calculated. While this figures approaches to the system’s response time such state is considered as the prior-to-fail state, and preparation-to-bypassing routine starts at this moment. The version of control system algorithm is proposed.