JPH0223206A - Control method for rotary machine - Google Patents

Abstract

PURPOSE:To operate stably and continuously rotary machine by switching a control amount set value of a driven machine to a prescribed value it an input amount exceeds the largest load set value, when driving apparatus input is increased/decreased in response to the load of the driven machine and restricting a load increase of the driven machine. CONSTITUTION:In a system where an air blower (a driven machine) 2 is driven by a steam turbine (driving machine) 1 and generated air flow is used as combustion air of a boiler 3, a rotational speed control unit 18 is provided so as to regulate the opening of a steam regulating valve 4a in order to cancel a speed deviation on the base of the output of a rotational speed detector PG which is provided on the steam turbine 1. A steam flow-in amount is also detected by a steam flow meter 4, and it is compared with the largest load set valve set by a largest load setting unit 16 by means of a largest load monitor unit 15, and when the flow-in steam amount exceeds the largest load set value, switching apparatuses 11, 14 are changed over to contact points a2, b2 sides, so that the output of a fuel supplying amount detector 5b and that of an air supplying amount detector 6b are inputted as set values into a fuel adjusting meter 10 and an air adjusting meter 12 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for a rotating machine such as a steam turbine or a blower.

[Conventional technology]

Figure 4 shows a conventional general control method for a rotary machine in which a blower 2, which is a driven machine, is driven by a steam turbine 1, which is a driving machine, and the air blown @2 is used as combustion air for a boiler 3. 1 is an explanatory diagram showing a steam turbine;
2 indicates a blower, and 3 indicates a boiler.

The steam turbine 1 is driven at a predetermined rotational speed by steam supplied through a turbine steam supply pipe 4, and the blower 2 is thereby driven. The air blown by the blower 2 is sent to the boiler 3 side through the air supply pipe 6, and on the way, it is mixed with fuel supplied through the fuel supply pipe 5 and is supplied to the boiler 3 for combustion. Steam is delivered to the point of demand through the

By the way, the input to a drive machine such as a steam turbine, specifically the amount of steam, etc., is usually adjusted according to the load required in a driven machine such as a blower driven by this drive machine. The side capacity is usually set to be the same as or larger than the capacity of the driven machine. However, because the drive function deteriorates over time due to deterioration of the drive machine itself, when the load required on the driven machine increases, a situation occurs in which the drive function cannot follow this increase. If such a state of insufficient drive function occurs, for example in the case of the drive machine shown in Figure 4, serious troubles may occur to the driven machine user, such as incomplete combustion of the boiler 3 due to insufficient air flow. There is a risk of inviting

[Problem to be solved by the invention]

However, in the past, almost no special measures have been taken for this purpose, and only the load on the driven machine side is determined and monitored; no measures have been taken to monitor the capabilities of the drive machine itself. (JP-A-53-90544, JP-A-53-1
No. 17485).

The present invention has been made in view of the above circumstances, and its purpose is to provide a rotating machine that can continuously operate stably by suppressing the output of the driven machine that exceeds the capacity of the driving machine. To provide a control method.

[Means for Solving the Problems] A method for controlling a rotating machine according to the present invention measures the amount of input to the driving machine, and when this measured value exceeds a predetermined maximum load setting value, the control method for a rotating machine according to the present invention The control amount setting value is switched to a predetermined value to suppress an increase in the load on the driven machine.

[Effect]

According to the present invention, troubles such as sudden emergency stop of the drive machine due to continuous over-capacity operation of the drive machine can be prevented.

〔Example] The present invention will be specifically explained below based on the drawings.

FIG. 1 is an explanatory diagram of a control method for a rotating machine according to the present invention, in which 1 is a steam turbine as a driving machine, 2 is a blower as a driven machine driven by the steam turbine 2, and 3 is a boiler. ing.

The steam turbine 1 is driven by turbine steam supplied through the steam supply pipe 4, and the rotation speed is input to the rotation speed control device 18 through the rotation speed detector PG attached to the steam turbine 1, and the rotation speed is inputted to a predetermined speed command value. The opening degree of the steam control valve 4a is adjusted to eliminate the deviation, and the steam turbine 1 is continuously operated at a predetermined rotation speed.

On the other hand, air from a blower 2 driven by a steam turbine 1 is supplied to the boiler 3 side through an air supply pipe 6 equipped with an air control valve 6a, but is also supplied through a fuel supply pipe 5 equipped with a fuel control valve 5a in the middle. The fuel is mixed with the fuel that has been mixed with the fuel, and is supplied to the boiler 3, where it is combusted.

Steam from the boiler 3 is fed through the steam feed pipe 7, but the amount of evaporation increases or decreases depending on the amount of demand on the steam user side, and is sequentially detected by the detector 7a, and is detected by the fuel converter 9.
The value obtained by converting the evaporation amount to the amount of fuel of the fuel type used is
Together with the signal from the setting signal switch 11, it is input to the fuel regulator 10 as a control setting value.

The fuel regulator 10 compares the required fuel amount input from the fuel converter 9 with the fuel supply amount read from the fuel supply amount detector 5b attached to the fuel supply pipe 5, and adjusts the fuel to eliminate the deviation. The valve 5a is adapted to be adjusted.

The setting signal switch 11 is configured such that the contact piece is always kept in contact with the contact a1, and is switched to the contact a2 by an overflow occurrence signal from the maximum load monitoring device 15, which will be described later. When the contact a2 is in contact, the set value set by the operator is selectively input, and when the contact a2 is in contact, the fuel supply amount from the fuel supply amount detector 5b is selectively input.

The detected value of the fuel supply amount detector 5b is determined by the above-mentioned fuel adjustment meter 1.
0, output to setting signal switch 11, ratio setting device 1
Output to 3.

The ratio setting device 13 calculates the required air amount corresponding to the fuel supply amount, and transmits this to the air controller 1 through the setting signal switch 14.
2 as a control amount set value. The air controller 12 compares the required air amount input from the ratio setting device 13 with the air supply amount detection value read from the air supply amount detector 6b, and operates the air adjustment valve 6 to eliminate the deviation.
It is designed to be adjusted by 8 odd.

The setting signal switch 14 is configured such that the contact piece is always kept in contact, and is switched to contact b2 by an overage signal from the maximum load monitoring device 15, and when the contact piece is in contact with When the ratio setting device 13
When the air supply amount detector 6b is in contact with the contact b2, the air supply amount detection value from the air supply amount detector 6b is selectively inputted to the air controller 12 as the control amount setting value. ing.

The maximum load monitoring device 15 compares the maximum load setting value input from the maximum load setting device 16 with the turbine steam amount taken in from the steam flow meter 4b attached to the turbine steam supply pipe 4, and When the predetermined maximum load setting value is reached or exceeded, it outputs a signal to the alarm device 17 to issue an alarm, and also outputs an overshoot occurrence signal to the setting signal switch 11.14 and the normally closed switch needle; Switch the contact piece of the setting signal switch 11 from contact a1 to contact a2, and switch the contact piece of the setting signal switch 14 from contact b1 to contact b2, and then open switch S- to output the signal from fuel converter 9. is configured to block.

The set value by the maximum load setting device 16 is empirically set as the maximum steam turbine capacity at that time or a value slightly lower than this based on the age of the steam turbine 1, the degree of deterioration of the steam turbine capacity over time, etc. Ru.

As a result, the fuel supply amount detected by the fuel supply amount detector 5b is input as a set value to the fuel regulator 10 through the setting signal switch 11, and thereafter the fuel supply amount is independent of the evaporation amount from the boiler 3. The fuel supply amount detection value, which is the actual control amount at that point in time, is maintained.

At the same time, the air supply amount detected by the air supply amount detector 6b is input as a set value to the air conditioner 12 through the setting signal switch 14, and thereafter the air supply amount is the actual control amount at that point. The amount is maintained at the detected value, and an increase in the load on the blower 2, which is a driven machine, is suppressed.

The control contents of the method of the present invention will be specifically explained based on the explanatory diagram of the control process shown in FIG. 2 and the graph shown in FIG. 3. FIG. 2(a) shows the control process according to the method of the present invention, and FIG. 2(b) shows the control process according to the conventional method. In Figure 3, (a) to (e) are respectively on the vertical axis,
The amount of evaporation from the boiler 3, the amount of fuel for the boiler 3, the amount of air, the rotation speed of the steam turbine, and the amount of turbine steam are shown.

In addition, the solid lines in FIGS. 3A to 3E show the control results when the method of the present invention is used, and the broken lines show the control results when the conventional method is used.

Now, when the steam turbine 1 is operating steadily at a predetermined speed [c in Figure 3 (d)], if the amount of evaporation from the boiler 3 increases due to an increase in demand (d in Figure 3 (a))
], the amount of fuel set from the fuel converter 9 to the fuel regulator 10 increases, and the amount of fuel supplied increases accordingly [e in Figure 3 (b)]. Also, the ratio is set for this amount of fuel supplied. As a result, the set air amount inputted to the air controller 12 as a control amount set value increases, and the air supply amount is also increased accordingly [FIG. 3(C), f]. As the load on the blower 2 increases in this way, the turbine rotational speed naturally begins to decrease [C' in Figure 3 (D)], and in order to recover from this, the turbine steam amount is increased ( Figure 3 (E)
(g)], from then on, as the load on the blower 2 increases, the turbine steam amount increases accordingly until it reaches the maximum load setting value determined according to the steam turbine capacity [
g' in Figure 3 (e)).

The control process up to this point is the same for both the method of the present invention and the conventional method, as shown in FIGS. 2(a) and 2(b). After this, in the conventional method, if the load on the blower continues to increase, the turbine steam amount is increased beyond the maximum load setting value.
g2 in Figure (e)], the steam turbine rotational speed decreases as the load increases due to insufficient steam turbine capacity [CZ in Figure 3 (d)), and as the amount of evaporation from boiler 3 increases. Although the fuel supply amount setting value and the fuel supply amount detection value are increased [Fig. 3 (a) d'], as a result of the insufficient air blowing of the blower 2 due to the decrease in the rotation speed of the steam turbine, the air supply amount setting value is increased. There is a large difference between the value [bl in Figure 3 (C)] and the air supply amount detection value [f2' in Figure 3 (C)], and boiler 3
is incompletely combusted, black smoke is generated, and eventually the amount of evaporation from the boiler 3 decreases due to poor combustion (aZ in Figure 3 (a)).

On the other hand, in the method of the present invention, when the turbine steam amount reaches the maximum load setting value determined according to the capacity of the steam turbine 1, the setting value for the fuel regulator lO is changed to the fuel input from the fuel supply amount detector 5b at that time. Switch to the supply amount detection value [e+3 in Fig. 3 (b), after which fuel supply control is performed using this as the set value, and at the same time the set value for the air conditioner 12 is also taken from the air supply amount detector 6b at that time. Switch to the air supply amount detection value [f in Figure 3 (c)],
Thereafter, air supply control is performed using this set value to suppress the load on the blower 2 and recover from the decrease in the turbine rotational speed [see cl in Fig. 3 (d).

Although the above-described embodiment describes a configuration in which the turbine steam amount is directly detected and compared with the maximum load setting value, the configuration is not limited to this, and for example, the fuel supply amount corresponding to the turbine steam amount is detected and the It goes without saying that a configuration may be adopted in which the maximum load setting value is compared with the maximum load setting value in terms of fuel.

Further, in the above-described embodiment, after the overflow occurrence signal is issued, the fuel supply amount detector 5 is used as the set value for the fuel adjustment 10.
Although the case where the detected value of the fuel supply amount by the air supply amount detector 6b is used as the set value for the air conditioner 12 and the case where the detected value of the air supply amount determined by the air supply amount detector 6b is used as the setting value for the air conditioner 12 has been described, the case is not limited to this. A reference value that allows continuous operation in a steady state may be determined in advance and used.

〔effect〕

As described above, with the method of the present invention, it is possible to prevent troubles such as sudden emergency stop of the drive machine due to continuation of an operating state exceeding the drive function, and to constantly operate in accordance with the deterioration of the drive function. The present invention has excellent effects, such as being able to significantly improve safety and reliability.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the control contents of the method of the present invention, and Figure 2 (
b), entry) are explanatory diagrams showing the control process of the method of the present invention and the conventional method, Figure 3 is a graph also showing the control process, and Figure 4 is a graph showing the control process.
The figure is an explanatory diagram showing the control contents of the conventional method. 1...Steam turbine 2...Blower 3...Boiler 4...Turbine steam supply pipe 5...Fuel supply pipe 6...Air supply pipe 7...Steam supply pipe 9... Fuel converter 10...Fuel adjuster 11...Setting signal switch 12...Air adjuster 13...Ratio setter 1
4...Setting signal switch 15...Maximum load monitoring device 16...Maximum load setting device 18...Rotation speed control device Patent applicant Noboru Kono, Patent attorney, Sumitomo Metal Industries Co., Ltd. ) (b) Diagram 2 Over Diagram No. 1 Diagram

Claims (1)

[Claims] 1. A method for controlling a rotating machine in which the input to the drive machine is increased or decreased depending on the load of the driven machine, the amount of input to the drive machine being measured, and the measured value being the maximum value determined. A method for controlling a rotating machine, characterized in that when a load setting value is exceeded, a control quantity setting value related to the load of the driven machine is switched to a predetermined value to suppress an increase in the load of the driven machine.