JPH05257501A - Regurating valve controller - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to obtain a regulating valve control device capable of manual intervention even when the control device 1 fails. [Structure] A control device 1 for controlling a control valve 7 in an automatic mode so that a process amount becomes a set value, and an operation amount of the control valve 7 in the automatic mode from the control device 1 is tracked and stored to switch to a manual mode. At this time, the analog memory 3 for outputting the stored operation amount of the control valve 7 to the control valve 7 and the control valve 7 is opened / closed in the manual mode when the control device fails or requires manual operation. CRT operation device 2 for outputting a valve operation command for
And input / output devices 23 and 24 which are provided independently of the control device 1 and which output a valve operation command from the CRT operation device 3 to the analog memory 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control valve control device for controlling a control valve in an industrial plant.

[0002]

2. Description of the Related Art Generally, various control valves are installed in various industrial plants. The operator monitors and operates these control valves at a selector station installed in an operation monitoring area such as a central control room. However, as the plant scale increases, the number of control valves increases, which makes it difficult to install many selector stations in a limited operation monitoring area. Therefore, a CRT operation device using a CRT is used as a driving operation device that exerts an effect under such circumstances. That is, the selector station selects the selector station which is given as an image on the CRT screen and is to be operated,
Driving operation is performed by touching the screen directly. This is intended to solve the problem of the installation space. A control valve control device using a conventional CRT operation device will be described with reference to FIG.

The control valve control device includes a control device 1 for a digital arithmetic unit used in the automatic mode, a CRT operation device 2 used in the manual mode, and an analog memory 3 for storing the control valve operation amount in the automatic mode. The switch 4 is mainly configured to switch between the automatic mode and the manual mode. The OR circuit 5 has a changeover switch 4 when the control device 1 has a failure or when the manual mode is selected.
The switching signal a is output to 14.

The changeover switch 4 selects the manipulated variable b of the control device 1 when the changeover signal a is OFF, and selects the output value c of the analog memory 3 when the changeover signal a is ON. To output the valve opening / closing d. The valve opening / closing signal d is converted from an electric signal to an air pressure signal by the electropneumatic converter 6 to open / close the control valve 7. Switching signal a is OFF
When it is, the control device 1 is in the state of controlling the control valve 7. This is because the signal from the process detector 8 is input through the analog input 9 and the result calculated by the PID calculator 10 is output as the manipulated variable b from the analog output 11 to open the control valve 7 according to a predetermined set value. It is in the state of controlling the degree. The manipulated variable b is also input to the analog memory 3, and the subtractor 12 of the analog memory 3 calculates the deviation between the manipulated variable b and the output value C of the integrator 13. When the changeover switch a is off, the changeover switch 14 is configured to input this deviation into the integrator 13, so that the output value C of the integrator 13 becomes equal to the value of the manipulated variable b. Being tracked.

Next, during manual operation by the CRT operation device, that is, when the switching signal is ON,
On the CRT screen of the CRT operation device 2, the selector station of the control valve 7 is selected,
The manual mode switch 15, the manual increase switch 16, and the manual switch 17 are displayed. Manual mode switch 1
5 is touch-operated on the CRT screen, a manual switching signal is transmitted to the control device 1 by the transmission signal, and the contact output 18
Outputs a manual mode selection signal e. Then, the switching signal a is turned on by the above-mentioned OR circuit 5, and the changeover switch 4 is switched so as to select the output value of the analog memory 3. As a result, the valve opening signal d of the control valve 7 becomes equal to the output value C. In this case, the output value C is the ON of the switching signal a.
Until that time, the operation amount b is tracked equally, so the opening of the control valve 7 does not change before and after this switching. That is, the bump restaurant suffer circuit is configured.
On the other hand, the changeover switch 14 is switched so as to select the manual increase / decrease signal 9 when the changeover signal a is turned on. If the manual increase switch 16 is touch-operated on the CRT screen in this state, the manual increase signal is transmitted to the control device 1 by the transmission signal, and the increase signal g is output from the contact output 19 and input to the analog memory 3. Similarly, when a touch operation is performed with the manual reduction switch 17, a reduction signal h is output from the contact output 20 and input to the analog memory 3. The subtractor 21 subtracts the increase signal g and the decrease signal h to create a manual increase / decrease signal f.
Then, the manual signal f is input to the integrator 13 by the selection of the changeover switch 14 to increase or decrease the output value C. With the above configuration, the output value C of the analog memory 3 can be increased / decreased to open / close the control valve 17 by a touch operation of the CRT operation device 2. That is, it is a system that can be operated manually. Further, a failure of the control device 1 is detected by the detector 22. When the control device 1 fails and the detector 22 is turned on, the changeover switch is changed over as in the case where the changeover signal a is turned on and the manual mode switch 15 is operated. As a result, the output value C of the analog memory 3 becomes the valve opening signal d.
This is an operation for switching for the purpose of maintaining the opening of the control valve 7 and maintaining the operation of the plant because the signal of the manipulated variable b is lost or becomes an abnormal value when the control device 1 fails.

[0006]

However, the control device 1
If the failure occurs, the value welding valve 7 is held at a constant opening degree and the plant operation can be continued for a short time, but it is difficult to continue the operation for a long time. That is, the control valve 7 must be opened and closed by operating the manual increase switch 16 and the manual decrease switch 17.

Further, since the input / output of the increase / decrease command from the CRT operation device 2 and the output of the increase / decrease command to the analog memory 3 are the functions processed by the control device 1, when the control device 1 is out of order, these are processed. Processing is not available and manual intervention is not possible. As described above, the conventional system is a control system that is not suitable for long-term plant operation.

[0008]

SUMMARY OF THE INVENTION A control valve control device of the present invention is a control device for controlling a control valve in an automatic mode so that a process amount becomes a set value, and a control valve in the automatic mode from the control device. When the control valve fails or the manual operation is required, the analog mode that outputs the stored operation value of the control valve to the control valve when the operation amount of CR that outputs a valve operation command for opening and closing the control valve with
The T operation device and the control device include an input / output device which is provided independently of the control device and outputs a valve operation command from the CRT operation device to an analog memory.

[0009]

In the present invention, since the input / output device for outputting the valve operation command from the CRT operation device to the analog memory is provided independently of the control device, manual intervention for the control valve is possible even when the control device fails. ..

[0010]

EXAMPLE An example of the present invention is shown in FIG. In the present invention, the output device 23 is provided independently of the control device 1. The input / output device 23 is the C of the CRT operation device 2.
The signals of each manual operation from the manual mode switch 15, the manual increase switch 16 and the manual decrease switch 17 displayed on the RT are input by transmission signals, and the contact outputs 24, 25, 26 are input.
To output the contact signals i, j, and k to the OR circuit 5 and the analog memory 3, respectively. Now, when the control device 1 fails and the detector 22 is turned on, the switching signal a is turned on. Then, the changeover switch 4 is changed over, and the output value C of the analog memory 3 becomes the valve openness signal d. The changeover switch 14 is switched so as to input the manual increase / decrease signal f to the integrator 13. C
When the manual increase switch 16 is operated by the RT operation device, the signal is transmitted to the input / output device 23, the contact signal i is output from the contact output 25, and the output value C of the integrator 13 is increased to increase the output value C of the control valve 7. Increase the opening. Similarly, when the manual reduction switch 17 is operated, the opening degree of the control valve 7 is reduced.

As described above, according to the embodiment, even if the control device 1 fails, the control valve 7 can be opened / closed by the manual operation from the CRT operation device 2 using the input / output device 23.

Next, another embodiment according to the present invention is shown in FIG.

In this embodiment, each control valve 7A, 7B, 7C is
Instead of installing the input / output device 23, one input / output device 24 is installed for the plurality of control valves 7A, 7B, 7C. As a result, the system has the feature of being a low-priced system in terms of cost.

Each component of the control devices 1A, 1B, 1C for the control valves 7A, 7B, 7C, the analog memories 3A, 3B, 3C, the changeover switches 4A, 4B, 4C, etc. is constructed in the same manner as in the embodiment of FIG. Has been done.

The input / output device 24 is a control valve 7A, 7B, 7C.
The input / output device 23 of FIG. 1 has three sets of transmission inputs and contact outputs so that manual intervention can be performed.

Thus, the input / output device 24 is the input / output device 23.
Although the device scale becomes larger than the above, as the number of control valves increases, the relative cost of the input / output device 24 to the entire system decreases and a practical system becomes possible.

[0017]

As described above, according to the present invention, since the input / output device is provided independently of the control device, when the control device fails, the control valve can be manually operated by the CRT operation using the input / output device. it can. As a result, the effect that long-term continuous operation of the plant can be achieved is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing another embodiment of the present invention.

FIG. 3 is a block diagram showing a conventional example.

[Explanation of symbols]

 1 Control device 2 CRT operation device 3 Analog memory 4, 14 Changeover switch 5 OR circuit 6 Electro-pneumatic converter 7 Control valve 8 Process detector 9 AI input 10 PID calculator 11 AO output 12, 21 Subtractor 13 Integrator 15 Manual Mode switch 17 Manual reduction switch 24, 25, 26 Contact output 22 Failure detector contact 23, 24 Input / output device

Claims (1)

[Claims] 1. A control device for controlling a control valve in an automatic mode so that a process amount is set to the setting amount, and a control device which controls the operation amount of the control valve in the automatic mode and stores the same when the control mode is switched to a manual mode. An analog memory for outputting the stored operation amount of the control valve to the control valve, and a valve operation command for opening and closing the control valve in a manual mode when the control device fails or requires manual operation. A control valve control device comprising a CRT operation device for outputting a control signal and an input / output device provided independently of the control device for outputting a valve operation command from the CRT operation device to the analog memory.