JPS6211361B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is for controlling a large number of control objects simultaneously and in parallel, such as an automatic burner control device, for example.
and relates to a multiplexed control device.

For large boilers such as those used in thermal power plants,
A large number of burners are used, and it is difficult to decide which one to ignite.
Whether to extinguish the fire is determined by a burner point/extinguishing switch installed in the central control room, or by an ignition/extinguishing command output by a computer based on plant requests. Furthermore, to ignite and extinguish one burner, insert the main burner, insert the ignition burner,
A series of sequence controls are required, including igniting the ignition burner, checking the main burner ignition, extinguishing the ignition burner, and pulling out the ignition burner. Conventionally, an automatic burner control device that automatically performs such ignition and extinguishing control for all burners has been generally constructed by providing a control unit for each burner. However, the basic ignition and extinguishing sequence is the same for all burners, and if a large number of control objects are to be controlled individually and of the same type, by adopting the storebalistic method, one It is possible to control multiple control objects with a control unit, and with this configuration, the amount of hardware can be significantly reduced compared to the conventional configuration in which individual control units are provided, and the average It is possible to lengthen the time between failures and reduce the amount of maintenance and inspection work.

Now, in a control device comprising such a storage logic type control unit, it is necessary to provide multiple control units in order to increase the reliability of the device against a failure of the control unit. However, if a backup control unit is provided for a control unit that is in charge of multiple control objects as described above, resulting in a so-called general duplex configuration, the conventional control unit that is in charge of a single control object can be replaced with a duplex configuration. The impact on the plant is greater when control unit switching fails in the event of a failure. In other words, assuming that the contact point for switching the control unit does not operate, a conventional multiplexed control unit would only make a single controlled object inoperable, but it would be possible to control multiple controlled objects. In the configured control unit, multiple control targets become inoperable all at once, which has a large impact on the plant.

In this way, when creating a multiplexed control device, it is necessary to take into account the high reliability of the switching contacts, but if this part is also multiplexed, the cost will increase.

Based on the above, in the present invention, when each control unit is given the function of controlling multiple control objects and is further multiplexed, it is possible to prevent the entire plant from failing when switching to a backup control unit. It is an object of the present invention to provide a multiplex control device that prevents disturbances as much as possible and does not impair control performance when properly switched.

A characteristic configuration of the present invention is that a first control device that controls a first operation target and a second control device that controls a second operation target are provided, and each control device controls its own operation target. It is equipped with a calculation program for the operation target and a calculation program for other operation targets, and inputs from the other operation targets as well as the input from the own operation target are constantly input, and outputs are obtained from each of the above two calculation programs. controls the first control device with the output of the first operation object, and controls the second operation object with the output of the second control device. In the event of an abnormality, two control objects are controlled using the output from one normal control device.

That is, in the example of the automatic burner control device described earlier, a control unit capable of controlling two burners is provided for each burner, and these are divided into two sets, and each control unit is While constantly receiving ignition and extinguishing commands for the two combined burners, it issues control output only to the one burner assigned to it under normal conditions, and if one of the combined control units fails, it will control the other burner. The unit backs this up, and in the end one control unit can handle two
The control output will be emitted to the burner on the stand.

Next, an embodiment of the present invention will be described regarding an automatic burner control device for 16 individual burners.

Figure 1 shows the arrangement of the burners, and the firing order of the burners is burners F1, F4, R2, R
3, F2, F3, R1, R4, F5, F8, R
6, R7, F6, F7, R5, and R8 are performed in this order. The extinguishing order is the opposite. Each burner consists of a main burner MBN and an ignition burner LTR. FN indicates furnace. The order of lighting and extinguishing is determined so as to balance the lighting and extinguishing with one pair before the can and one pair after the can, and when the number of burners increases, it is determined based on the same idea. In this embodiment, F1 and F2 are placed in group 1, F2 and F3 are placed in group 2, and similarly, R7 and R8 are placed in group 8.
Two control units are provided for each group.

Figure 2 shows one of the burners in the burner automatic control system.
This is a block diagram of the part that controls the group. 1 and 2 are input circuits for limit switch signals from the field and switch operation signals from the central control room, and 3 and 4 are store logic type logic circuits. The constructed burner control unit, 5 and 6, is a parity error in the self-failure diagnosis circuit of burner control unit 3 and 4; the circuit for detecting a program congestion failure, 7 and 8 is an output circuit, and 9 is a failure in burner control unit 3. 10 is a switching unit that switches to the other paired burner control unit 4 when the burner control unit 4 fails, and 10 is a switching unit that switches to the other paired burner control unit 3 when the burner control unit 4 has a failure. , 11, 12 are burner operating ends.

Next, an example will be described using Group 1 as an example.
The input signal of the F1 burner is inputted by the input circuit 1 to the burner control units 3 and 4, respectively, and the input signal of the F2 burner is inputted by the input circuit 2 to the burner control units 3 and 4, respectively.

The control unit 3 performs logic calculations for the burners F1 and F2. The burner control unit 4 also performs logic calculations for the burners F1 and F2. Here, the self-failure diagnosis circuit 5,
When no failure is detected in 6, the switching relays built in the self-failure diagnosis circuits 5 and 6 are de-energized, and the output signal of the output circuit 7 is only the signal of the burner F2 among the logic operation signals of the burner control unit 4. be done. This means that burner control unit 3 controls burner F1, and burner control unit 4 controls burner F2.

Next, consider a case where the burner control unit 3 breaks down. Due to a failure in the burner control unit 3, the failure detection relay of the self-failure diagnosis circuit 5 is operated, and the signal from the burner control unit 4 is outputted to the burner operating end 11 via the output circuit 8 by the switching unit 9. Furthermore, when the burner control unit 4 fails, the failure detection relay of the self-failure diagnosis circuit 6 operates, and the switching unit 10 causes the signal from the burner control unit 3 to be transmitted via the output circuit 7 to the burner operating end 1.
2 is output. As explained above, when burner control unit 3 fails, burner F1 is backed up by burner control unit 4, and when burner control unit 4 fails, burner F2 is backed up by burner control unit 3.

If a burner control device is constructed using the combination of burner control units described above as a unit, when viewed as a burner control system as a whole, it is a distributed system with one set of burner control units for each burner, which improves reliability. A control unit is provided twice for each burner, resulting in a dual system control device. With such a control device, it is possible to continue control without disturbing the entire plant even if one control unit fails.

FIG. 3 shows the configuration of the control unit shown in FIG. 2, with an additional output collation function between the units.

The output comparison detection circuit 13 compares all control outputs output from the output circuits 7 and 8 of the control units 3 and 4 by exclusive OR.
Furthermore, the outputs of the self-failure diagnosis circuits 5 and 6 of the control units 3 and 4 are inputted, and when both have failure detection outputs, the relays of the output signal lock circuits are driven to send control signals to the burner operating ends 11 and 12. The state of burners F1 and F2 is maintained in the state when the burners are cut off.

In addition, as a result of checking the control outputs, even though both outputs do not match, there may be no failure detection output from either self-failure diagnosis circuit, or conversely, there may be cases where the control output does not match even though there is a failure detection output. If the comparison results match, the self-failure diagnosis circuit 5,
6, or there is an abnormality in the output verification detection circuit 13. In this case, the alarm device 15 issues an alarm to notify the operator.

If the control device is configured using the configuration shown in FIG. 3 as a unit, it is possible to always maintain the self-failure diagnosis function of the control unit in a normal state, and it is more reliable than the embodiment explained in FIG. 2. It becomes a highly flexible control device.

As explained above, according to the present invention, when one control unit is given the ability to control multiple control objects and is further multiplexed, a plant that occurs when switching to a backup system fails. A control device can be obtained in which the influence on the entire system can be minimized and control performance is not impaired when switching is performed correctly.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing the configuration of a burner device to be controlled according to an embodiment of the present invention, and FIGS. 2 and 3 are block diagrams each showing one unit of the control device according to an embodiment of the present invention. . 1, 2... Input circuit, 3, 4... Burner control unit, 5, 6... Self-failure diagnosis circuit, 7, 8... Output circuit, 9, 10... Switching unit, 11, 12... Burner operation end, 13... Verification detection 14...Output signal lock circuit, 15...Alarm device, FN...Furnace, MBN...
Main burner, LTR...ignition burner.

Claims (1)

[Claims] 1 A first input circuit that inputs an operation state signal etc. for the first operation end, a second input circuit that inputs an operation state signal etc. for the second operation end;
and the second input circuit to obtain the output from the first input circuit.
first and second control units that create operation signals for the and second operation end and output both of them, respectively;
and a first switching circuit that inputs two operating signals for the first operating end provided by the second control unit and selects one of them; a first switching circuit that is driven in accordance with the output of the first switching circuit; an operating end, a second switching circuit that inputs two operating signals for the second operating end provided by the first and second control units and selects one of the operating signals, and is driven in accordance with the output of the second switching circuit. The first switching circuit always selects the output on the first control unit side, selects the output on the second control unit side when the first control unit is abnormal, and selects the output on the second control unit side when the first control unit is abnormal. A multiplex control device characterized in that the second switching circuit always selects the output from the second control unit and selects the output from the first control unit when the second control unit is abnormal.