JPH0262488A - Remote control of valve in plant - Google Patents

Abstract

PURPOSE:To achieve a high precision setting of an opening degree by providing a means to calculate the direction of opening or closing and its output time with relation to the opening degree characteristics of a subject valve for control on the side of a host computer. CONSTITUTION:A desired control value is inputted from a CRT first, an action direction for opening or closing a subject valve and an operation time for continuing the action direction are determined based on opening degree characteristics corresponding to the valve, and a first action command (position select) is outputted to a plant. When a response to the output is received, a second action command (action select) for the opening or closing direction is outputted to the plant, and when a response to that is received, check of an operation time elapsed is started after a comparison check of the desired control value and opening degree value for the valve, so if the desired value or the operation time is reached, a valve stopping command is outputted to the plant. High precision setting of an opening degree can thus be enabled in a simple constitution of a system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a remote control system for various equipment in a plant monitoring and control system.

[Conventional technology]

Conventionally, in this type of remote control method for valves in a plant, a setting i is set on the plant side to control the opening of the valve.
The host computer on the center side transmits the desired opening degree to the setting device on the plant side. The setting device on the plant side has a feedback control system based on so-called opening setting value control or opening monitoring, which adjusts the opening until the valve reaches the specified opening.

[Problem to be solved by the invention]

In the conventional remote control method for valves in a plant as described above, the opening degree is transmitted from the host computer to the setting device on the plant side, and the opening degree of the valve is adjusted by this setting device.
Equipment including a setting device is required on the plant side, making it expensive. In addition, it takes time for the plant side to transmit the valve opening value to the host computer, and even if a valve operation stop signal is output when the opening set by the computer is reached, the opening may be delayed due to transmission delays. The disadvantage is that the value deviates from the set value, making it impossible to set the opening with high precision.

[Means to solve the problem]

The remote control method for valves on a plant according to this invention is as follows:
The host computer has means for storing the opening characteristic of the valve to be controlled and calculating the opening or closing direction and its output time for the set opening characteristic.

[For production]

This invention makes it possible to set the opening degree with high precision, and it is possible to reduce the cost of the system.

[Actual weaving example]

FIG. 1 is a conceptual flowchart showing an embodiment of the remote control method for valves in a plant according to the present invention, and FIG. 2 is a diagram showing the opening characteristics of the valve. The horizontal axis is the opening (%). ), the vertical axis shows time (1), vc is the current valve opening, ■
, is the target valve opening (control target value) 1, δt is the target valve operation time, T is the valve operation time from 0 to 100%, and Tc is the idle time until the valve actually operates. shall be.

Next, the operation of the remote control system for valves on a plant with the above configuration will be explained. First, in step S1, a control target value is input from the CRT. And step S,
Then, the direction of opening or closing of the valve is determined based on the input control target value and the opening characteristic corresponding to the valve to be controlled. Then, in step S8, the operation time for continuing the opening or closing direction of the valve is determined.

In this case, the target operation time and opening/closing direction of the valve can be determined using the following equation.

However, the opening direction is ve-v, and the closing direction is vo-v.

〉0 is output to the plant. Then, in step S, when a response to the output of this first behavior command is received from the plant, a second behavior command (operation selection) in the opening or closing direction is received.
output to the plant. Then, in step s6, when a response to the second behavior output is received from the plant, a comparison check is made between the valve control target value and the opening value, and then step S? Now, start checking the operation time elapsed.

The checks in steps S6 and S are performed until the valve opening value reaches the target value or the operation time elapses. Then, in step S8, when the target value or the operation time has elapsed, a valve stop command is output to the plant, and the process ends.

〔Effect of the invention〕

As explained in detail above, according to the remote control method for valves on a plant according to the present invention, the opening characteristic of the valve is determined by operating the actual valve in the plant. Once the opening characteristic is determined, the current opening, the operating time until the control target value is reached, and the opening/closing direction can be easily determined. For this reason,
This eliminates the need for a setting device on the plant side to set the opening degree, thereby reducing the system cost and making it possible to set the opening degree with high precision.

[Brief explanation of the drawing]

FIG. 1 is a conceptual flowchart showing an embodiment of a remote control system for valves on a plant according to the present invention, and FIG. 2 is a diagram showing the opening degree characteristics of the valve.

Claims (1)

[Claims] In a plant monitoring and control system that remotely controls various equipment, the host computer stores the opening characteristics of the valve to be controlled, and calculates the open or close direction and its output time based on the set opening characteristics. 1. A remote control system for valves on a plant, characterized in that a means is provided.