JPS58220929A - Controller of furnace top pressure collecting turbine equipment - Google Patents

Abstract

PURPOSE:To reduce a fluctuation in a furnace top pressure as low as possible, by installing a controller, which is backed up by a regulator on the blast furnace side when a controller on the turbine side is brought to a trouble or performs a reverse operation to the above. CONSTITUTION:On the blast furnace 1 side, a signal of a pressure indicating regulator 10 is controlled by bringing the characteristics of a bypass valve 4 into a rectilinear one by means of a high selector 32 and a function operator 33. On the turbine 6 side, a signal of a pressure indicating regulator 13 enters a ratio setter 36, and outputs of another function operator 37 and a pressure control signal are selected at a low level via a low selector 38 to control them by means of a governor valve 5 and a static vane driving device. The two control systems are selectable by a switching device 31, and a regulator in an inoperative state, follows up a regulator operated by means of an external feedback signal. This enables reduction of a fluctuation in a pressure at a furnace top to as low as possible since an insensible zone is prevented from being created if the switching device 31 is happened to be operated.

Description

[Detailed description of the invention] It is something to do.

FIG. 1 shows a control device generally employed in a conventional furnace top pressure recovery turbine (hereinafter referred to as a turbine for convenience) driven by the furnace top pressure of a blast furnace 1. However, the blast furnace gas generated in the blast furnace 1 is removed by a dust catcher 2, a penturi scrubber 3, etc., and when the turbine 6 is not operated, the pressure is reduced by a septum valve or bypass valve 4, and the blast furnace gas is removed from the top of the furnace. A control signal is obtained by comparing the pressure detected by the pressure transmitter 8 and the set pressure given to the pressure indication adjustment δ110 by the hand controller 9, and the furnace top pressure is kept constant by the septum valve or bypass valve 4. controlled.

11.

Generally, a butterfly valve is adopted as the septum valve or bypass valve 4, and the valve opening is used at a valve opening of about 30 to 70%, which provides the best controllability, at a normal blast furnace gas amount.

On the other hand, when operating the furnace top pressure recovery turbine equipment, the hand controller 11 and subtractor 12 adjust the set pressure of the pressure instruction adjustment a116 for turbine control from 0.03 to 0.
．． The control signal is set at approximately 0.05 kg/CrrL', that is, lower than the pressure command adjustment ifHO on the blast furnace 1 side, and this control signal is sent to the electric governor 14, which controls speed control, power control,
A necessary signal is selected from control signals such as pressure control, and the signal distributor 15 divides the signal to the governor valve 5 and stator vanes, and the governor 5, stator vanes, and drive device 16 transmit the signal to the turbine 6.
The blast furnace gas energy is recovered as electricity by the generator 7.

In some cases, the stator blade angle is fed back by the stator blade angle transmitter 22 when correction of the stator blade operation delay is required.

With such a conventional control system, which at first glance has no apparent defects, when actually operating the blast furnace 1, which is required to operate while avoiding top pressure fluctuations as much as possible, it has been pointed out that there are the following drawbacks. ing.

That is, when the turbine 6 enters pressure control operation, the furnace top pressure drops from 0.03 to 0.05 kg/crIL2, that is, the low value set on the hand controller 11, and the blast furnace gas generation When the amount of generated electricity increases, the power control of the electric governor 14 is selected, and when the turbine 6 side suppresses the amount of gas swallowed, the furnace top pressure increases to the set value of the pressure command adjustment 110, that is, the turbine 6
0.03 to O during normal operation. 05kg/crIL
2, the pressure indicating regulator 10' generates a control signal and opens the septum valve or bypass valve 4. Therefore, if the top pressure fluctuation is large or once the turbine 6 is at its full generating capacity, the septum valve will open. Or bypass valve 4 (7) After entering the control, the gas amount decreases, pressure command adjustment, rtlo
Even if the control signal of
Since the output of the pressure indicator controller 16 will not decrease unless it falls below the set value, a dead zone may occur, or if the operating pressure of the blast furnace 1 changes, power control will be affected due to the characteristics of the turbine 6. As the furnace top pressure increases, the output decreases gradually, and as the furnace top pressure decreases, it increases. Therefore, by setting the anti-reset windup of the pressure indicator controller 16, the output of the pressure indicator controller 16 may be increased more than necessary. Even if you try to avoid the increase and eliminate the dead zone before actually entering the turbine control, it is actually impossible, or if the furnace top pressure rises suddenly, it will take a while before the front pressure of the turbine 6 actually rises. Because there is a slight time delay, the signal of the pressure indication adjustment a116 increases, and even if the governor valve 5 or the stator vane of the turbine 6 opens, the front pressure rises, power control is applied, and the governor valve 5 or the stator vane opens. There are drawbacks such as the septum valve or bypass valve 4 opening only when the furnace top pressure increases by 1" and exceeds the set value of the pressure indicating controller 10. All of these drawbacks cause large fluctuations in the furnace top pressure. There was a request for improvement.

Moreover, if we take a 15,000 kW class furnace top pressure recovery turbine equipment as an example, the Cv value on the turbine 6 side is usually 15,000.
A point close to full opening is selected as the normal operating point, and the pressure command adjustment d1 output also changes from 80% to 0% as the reversal point.

On the other hand, the septum valve or
Most of them have a CV value of about 000, and the output of the pressure indication adjustment 111 is about 30 to 5°%;
There is a considerable difference in the adjustment 31 gain setting with I3, so in case of any trouble, there are two pressure indicating controllers 10 and 13 installed mainly for pickup, but there is little flexibility. It is not very effective (because of the troubles in the loop of the pressure indicating regulator 13 [well, the power that can be backed up by the pressure indicating regulator 8110; troubles in the pressure indicating regulator 10 cannot be backed up by the pressure indicating regulator 16, etc.). There was also.

Therefore, the present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional technology, and when there is a problem with the turbine side control device, the blast furnace side pressure indicating controller is set to 1.

The object of the present invention is to provide a control device that can back up the pressure indication adjustment on the turbine side in the event of trouble in the pressure indication adjustment on the blast furnace side.

That is, the control device for the top pressure recovery turbine equipment of the present invention is as follows:
In a furnace top pressure recovery turbine equipment in which a septum valve or bypass valve is provided in parallel with a furnace top pressure recovery turbine driven by the furnace top pressure of a blast furnace, the maximum CV value of the septum valve or bypass valve and the furnace top pressure recovery turbine are By performing CV value matching to linearize the maximum CV value of the top pressure recovery turbine, the pressure indicating controller on the blast furnace side will back up in the event of trouble with the control device on the furnace top pressure recovery turbine side. In addition, in the event of a problem with the pressure indicating regulator on the blast furnace side, the pressure indicating regulator on the furnace top pressure recovery turbine side will back up, and the top pressure on the blast furnace side of the control device It is also effective to control the septum valve or bypass valve using the equal output curve of the top pressure recovery turbine that corresponds to the rated output of the generator driven by the top pressure recovery turbine. The opening degree of the septum valve or bypass valve side and the opening degree of the furnace top pressure recovery turbine side are made to be the same based on the output signals of the pressure indication adjustment RTL on the blast furnace side and the pressure indication regulator on the top pressure recovery turbine side. By doing so, the two pressure indicating controllers may be made to follow the output of their counterpart by external feedback, so that backup can be performed bumplessly.

Hereinafter, the present invention will be explained based on an embodiment shown in FIG. 2. Blast furnace gas from the blast furnace 1 is removed by a dust catcher 2, a venturi scrubber 6, etc., and a septum valve or bypass valve 4, Alternatively, while the pressure is reduced by the governor valve 5 and the turbine 6, the furnace top pressure is controlled to be constant.

When the blast furnace gas flows through the turbine 6, energy is recovered by the generator 7.

As these control devices, the furnace top pressure is detected by the furnace top pressure transmitter 8 on the blast furnace 1 side, and a setting signal is given to the pressure indication controller 10 by the hand controller 9, and the pressure indication adjustment δ1
The characteristics of the septum valve or bypass valve 4 are linearized using the high selector 62 and the function calculator 63, and the septum valve or bypass valve 4 is controlled.

On the other hand, a furnace top pressure transmitter 8 is used as a turbine 6 side control device.
The detected pressure is set to the pressure indicating controller 10 on the blast furnace 1 side by the ratio bias setting device 34, for example, 10', 1.
kl? The control signal of the pressure indicator controller 16 is adjusted to the Cv value by the ratio setter 66, and the detection signal of the furnace top pressure transmitter 8 is used to The signal from the function calculator 37 that generates the last control signal for power control according to the signal, the pressure control signal, and the output signal of the function calculator 37 are guided to the electric governor 14 via the low selector 68. In the case of normal furnace top pressure control, the signal is selected at a low level, and the furnace top pressure is controlled by the signal distributor 15 using the governor valve 5, stationary blades, and drive device 16.

Here, in some cases, the actual Cv@ of the turbine 6 is calculated from the stator blade angle detected by the stator blade angle transmitter 22, and the smaller one of the pressure control signal and the calculated actual Cv value is A signal obtained by selecting with the low selector 26, restoring the CV value with the ratio setter 24, and subtracting the CV value of the turbine 6 from the output of the pressure indicating controller 16 with the subtracter 12 is sent to the output selector 62 and the function calculator 66. via which the septate valve or bypass valve 4 is controlled.

The blast furnace side control system and the turbine side control system are the switching valve 3
1, and the pressure indicating controller on the unused side is set so that it follows the output of the pressure indicating regulator on the used side by an external feedback signal. is controlled to avoid creating a dead zone when entering backup.

In addition, in order to effectively control the important blast furnace 1 side even in the event that a problem occurs with the 81 device on the turbine 6 side, the furnace top pressure transmitter 8, hand controller 9, and pressure indicator adjustment are necessary. 3110, ratio/earth setting device 64, pressure stripe adjustment 1t13. - It is preferable that the +rl device'dL source of the iselefter 62, the function calculator 66, and the subtractor 12 be supplied with power from the blast furnace control power source, and that these devices be attached to the blast furnace control panel together with the switch 61.

Such a control device is prepared, and pressure indicating regulators 10 (PIC-(11) and 13 (PIC-02) shown in FIG.
) and signal correction based on the CV value of the turbine 6 shown in FIG.

That is, to explain CV value matching with reference to FIG. 3, when the CV value of the turbine 6 is only the governor valve 5 and there is no stator blade, the range used for controlling the governor valve 5 is linearized, and the maximum CV is
Suppose the value is A.

Similarly, in the case of a turbine 6 with stationary blades, the range used for controlling the governor valve 5 is linearized, and since it essentially has almost linear characteristics on that straight line, linearization is generally necessary. Signal distribution is performed inside the signal distributor 15 so as to take advantage of the characteristics of the static vanes.

It is assumed that the Cv value of the maximum opening degree of both the speed governor valve 5 and the stator vane is A for control purposes.

On the other hand, it is assumed that the septum valve or the bypass valve 4 is also linearized and its maximum Cv@ is B.

Here, it is theoretical that both the pressure indicating regulators 10 and 13 should cause the septum valve or the bypass valve 4 to be fully open when the output signal is 10'0%, and this will also be explained here.

That is, for example, B = 40000, A = 15000
In this example, A/B = 0.375, so the ratio of the ratio setter 66 in FIG. 2 is determined so that the turbine 6 side has the maximum CV value when the pressure indication adjustment 31 output is 37.5%.

Therefore, in the case where the overall signal is 4 to 20 mA, the maximum opening on the turbine 6 side in Fig. 2 is also 100 mA.
For example, when matching the % signal, the ratio setter 6
6 may have a slope of 4.000/15000 = 2.667.

On the other hand, the signal sent back from the turbine 6 side to the blast furnace 1 side may also be sent back at 1/2°667 using the ratio setting device 66 shown in FIG.

If such CV value matching can be realized, as shown in Fig. 4, the output will correspond to the rated output of the generator 7 against the furnace top pressure, which constantly changes depending on the operational status of the blast furnace 1 due to the turbine characteristics and changes rapidly depending on the furnace conditions. It is possible to set the equal output curve of the turbine 60 as the relationship between the CV value of the turbine 6 and the furnace top pressure, and as described above, by matching the CV value, it is possible to 6, the septum valve or bypass valve 4 can be opened without delay when the pressure indicator controller output increases.

For example, in FIG. 2, the output of the pressure indicating controller 16 is 37.5% and the output of the ratio setting device 66 is 100%, and the function calculator 33 has the characteristics shown in FIG. However, when the furnace top pressure is 80%, the output of the pressure indicator controller 13 changes to 2 due to a change in the gas amount.
If it changes from 6.25% to 31.875%; the output of the ratio setter 36 will change from 70% to 85%.

In the case of 26.25%, the output of the ratio setter 36 is 70%.
According to FIG. 4, the output of the function calculator 67 is equal to the furnace top pressure 8
0% is 76%, and the low selector 68 sends the lower 70% to the electric governor 14.

If the engine is operated under pressure control, this signal is used by the signal distributor 15 to set the CV value of the turbine 6 to 70%, and if the stator vanes match the signal, the output of the low selector 26 is 70%. .

If this is set to 1/2°667 by the ratio setter 24, it becomes 26°25%, and the output of the subtractor 12 is 26°25%.
-26.25 = 0%, and the septum valve or bypass valve 4 is closed.

At this time, if the pressure indicating controller output increases to 28.5%, the output of the ratio setting device 66 will become 76%.For simplicity, if the furnace top pressure remains at 80%, then at this time. It becomes a turning point.

:ζ In addition, the pressure indication adjustment 31 output increases to 31,875
%, the output of the ratio setter 66 is 85%, but the output of the function calculator 63 is 76%, and the low selector 38 selects 76%.

Therefore, since turbine 6 remains at 76% CV value,
The output of the ratio setter 24 is 28.5%.

Therefore, the output of the subtracter 12 is 31.875-28.5=
3.375%, C of septum valve or bypass valve 4
V value 4%, i.e. 40000 x O,03375=
It will be open for 1350 minutes.

This is the CV value that could not be followed by turbine 6, that is, 8
5-76 = 9%, 15000 x 00 (19=
Same as 1350.

In this case, even if the furnace top pressure changes with a change in the pressure indicator controller output, the output of the function calculator 63 follows it, maintains the turbine 6 side at the Cv value corresponding to the generator output, and adjusts the pressure indicator. The shortfall in the Cv value required by the meter output is sent to the septum valve or bypass valve 4, and the total CV value becomes the Cv value required by the pressure indicating controller 16.
・There is no need to explain in detail.

Hereinafter, it will be explained in accordance with the order of operation that the present invention can solve the conventional drawbacks.

First, in FIG. 2, before starting the operation of the turbine 6, the pressure indication adjustment 8116 is set to the ratio bias setting device 3.
4 to set it higher than the set value of the pressure indicating regulator 10, and the switch 61 is set to select the pressure indicating regulator 10 side.

At this time, the output of the pressure indicating regulator 16 is zero in the conventional method, but in the method of the present invention, it follows the output of the pressure indicating regulator 3110 by external feedback.

When operating the turbine 6, first, the setting value of the pressure indicating regulator 13 is gradually lowered using the ratio bias setting device 34 to the same setting as the pressure indicating regulator 10, and the switching valve 61 is switched to the pressure indicating regulator 16 side.

At this time, the timing of switching is determined based on the operational status of the blast furnace 1, and the switch can be made to the pan press without any pressure fluctuation.

On the other hand, in the conventional method, the turbine 6 starts up, the intake of gas into the turbine 6 increases, and the septum valve or the bypass valve 4 is later closed to the turbine 6 completely independently of the timing desired by the blast furnace 1 side. 0 at the timing of completion of startup.
This occurs with a pressure difference of 0.03 to 0.05 kg/cm2, which is improved as described above.

Immediately after the pressure is switched to the indication controller 13, the turbine 6 is stopped, so the low selector bus of the electric governor 14 is set to zero, so the pressure indication adjustment 311
The output of 3 is subtracted by zero by the subtracter 12 and directly goes to the septum valve or bypass valve 4.

When the turbine 6 is started from this state and the Cv value of turbine B gradually increases, the amount of gas flowing to the turbine 6 side increases while controlling the furnace top pressure, and the septum valve or bypass valve 4 closes.

When the gas amount is less than the capacity of the generator 7, the septum valve or bypass valve 4 is fully closed, and the furnace top pressure is controlled by the governor valve 5 and stationary blades of the turbine 6, and the startup of the turbine 6 is completed. In this state, the amount of gas generated gradually increases, and the output of the pressure indication adjustment 31 gradually increases until it approaches the rated output of the generator 7. The output of the above-mentioned function calculator 67 maintains the turbine 6 side at a CV@ suitable for the furnace top pressure at that time, and the extra signal is sent to the septum valve or bypass valve without a dead zone and without delay.

In this way, the furnace top pressure of the conventional method is reduced to 0.03~(). 0
An increase of about 5 kg/C7n2 can be avoided.

Historically, once the septum valve or bypass valve 4 is open, when the gas amount decreases and the output of the pressure indication adjustment 16 decreases, the septum valve or bypass valve 4 closes first. There is no need to set an anti-reset windup, which was necessary in the method, or to change settings according to the furnace top pressure, there is no dead zone, and there is no fluctuation in the furnace top pressure.

In addition, when operating with the seven-node valve or bypass valve 4 closed, if the top pressure suddenly increases and the output of the pressure indication adjustment 31 increases rapidly, as explained in Fig. 4 above, , Shin9
The septum valve or the bypass valve 4 can be opened when the number is boosted, and the drawbacks of the conventional system are eliminated.

Pressure indication adjustment? 110 and pressure indication R# #t 1
The gain settings of 3 can also be made almost the same according to the present invention. For example, in the pressure command adjustment J116, even if an abnormality occurs in the turbine 6 side speaker during operation of the turbine 6 and the turbine 6 stops, the subtractor 12 sends a signal to the septum valve or bypass valve 4. rotation, furnace top pressure of 0.0
If there is a fluctuation of 3 to 0.05 kg/C or something like this with the conventional method, in Figure 1, the pressure indication adjustment δ110 waits at zero output, so the output signal will be appropriate. Problems such as dead zones until the control level reaches a certain level and overshooting caused by large changes are also eliminated.

In addition, if an abnormality occurs in the utility of the turbine 6 side, by immediately operating the switch 31 shown in Fig. 2, the septum valve or the bypass valve 4 can be controlled and backed up. When an abnormality occurs in the pressure indicator controller 13, by operating the switch 61 as well, the pressure indicator controller 13
It can be backed up by

As is clear from the explanation below, the present invention solves the drawbacks of the conventional technology, and at the same time, when there is trouble with the turbine side control device, the blast furnace side pressure indication f! It has the advantage that the fi'jil performs back-amplification and the pressure indication adjustment 31 on the turbine side can back up when there is a problem with the pressure indication adjustment 31 on the blast furnace side, which is extremely effective in practice.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the control of the conventional furnace top pressure recovery turbine equipment, FIG. 2 is an explanatory diagram showing the control of the furnace top pressure recovery turbine equipment in the embodiment of the present invention, and FIG. A conceptual diagram illustrating the CV value matching between the septum valve or bypass valve and the turbine. Figure 4 is a conceptual diagram illustrating the CV value matching between the septum valve or bypass valve and the turbine. FIG. 2 is a conceptual explanatory diagram of a function calculator for sending an output to a septum valve or a bypass valve. 1... Blast furnace, 4... Septum valve or bypass valve, 5
... Speed regulating valve, 6... Turbine, 7... Generator, 8
...Furnace top pressure transmitter, 10...Pressure indication adjustment a1.
12... Subtractor, 13... Pressure indicating controller, 14...
...Electric governor, 15...Signal distributor, 16...
Drive device, 22...Stator vane angle transmitter, 24...Ratio setter, 61...Switching valve, 66...Ratio setter. Agent Patent attorney Makoto Ogawa - Patent attorney Masaru No Shiro Patent attorney Kazuhiko Saishita Figure 3 Turbine Cv value c%) (Function calculator output)

Claims (1)

[Scope of Claims] 1. In a furnace top pressure recovery turbine equipment in which a septum valve or a bypass valve is provided in parallel with a furnace top pressure recovery turbine driven by the furnace top pressure of a blast furnace, the maximum pressure of the septum valve or bypass valve is By adjusting the CV value so as to linearize the CV value and the maximum CV value of the top pressure recovery turbine, in the event of trouble with the control device on the furnace top pressure recovery turbine side, the pressure indicating regulator on the blast furnace side control device 8 for furnace top pressure recovery turbine equipment, characterized in that the pressure indication regulator 81 on the blast furnace side backs up, and when there is a problem with the pressure indication regulator 81 on the blast furnace side, the pressure indication regulator on the furnace top pressure recovery turbine side backs up. Driven by the furnace top pressure on the blast furnace side and the furnace top pressure recovery turbine, the control device adjusts the CV value so that the maximum CV value of the bypass valve and the maximum CV value of the furnace top pressure recovery turbine are linearized. The top pressure recovery turbine according to claim 1, wherein the septum valve or the bypass valve is controlled using a constant output curve of the top pressure recovery turbine that corresponds to the rated output of the generator. Equipment control device. 3 Pressure instruction adjustment Ml on the blast furnace side of the control device that adjusts the Cv value so as to linearize the maximum CV value of the septum valve or bypass valve and the maximum CV value of the furnace top pressure recovery turbine. By making the opening degree of the septum valve or bypass valve side and the opening degree of the furnace top pressure recovery turbine side the same based on the output signal of each pressure command adjustment a1 on the top pressure recovery turbine side, the above two pressures can be adjusted. Claims 1 and 2 are characterized in that the indicating controllers are made to follow the output of their counterpart by external feedback, so that backup can be performed bumplessly.
A control device for the furnace top pressure recovery turbine equipment described in Section 3.