| 摘要 |
PURPOSE:To reduce a transient responsive period and improve the control stability of a temperature-flow rate cascade control system by a method wherein a target flow rate of a secondary control loop can be initially set at a given value at the time of target temperature setting. CONSTITUTION:The temperature PV1 of a control object P1 changes a target flow rate SV of a flow rate indicator and adjustment FC in a secondary control loop L2 by the use of a primary operation amount MV obtained as an output from a temperature indicator and adjustment TC in a main control loop L1, and the control is carried out by operating a steam flow rate adjust valve V based on the output M from the flow rate indicator and adjustment FC. In such a cascade control system, an arithmetic part A which obtains an increment of a primary operation from the precedent operation amount and the current operation amount, and another arithmetic part B which obtains the current target flow rate based on the output from the arithmetic part A are provided. Also an initial flow rate target value setting part H is provided through which a target flow rate is arbitrarily set manually from outside and made to be given to a flow rate target value retaining par BH of the arithmetic part B. |
