JPH0535338A - Rotational frequency control method for fan in joint duct system - Google Patents

Abstract

PURPOSE:To prevent control from being disabled based on the disturbance of controlled variables such as the circulating pressure or circulating rate, etc., of fluid and the change of setting at a device to be supplied with the fluid provided at each duct. CONSTITUTION:In a joint duct system equipped with supply side fan devices 5B and 6B provided on the input sides of individual ducts 3 and 4 as the paths of burning air for respective furnaces 1 and 2, control valves 7 and 8 for the feedback control of the circulating pressure or circulating rate of burning air provided on the output sides of furnaces 1 and 2 of the individual ducts 3 and 4, and exhaust side fan device 12 provided at a joint duct 11 joined to the individual ducts 3 and 4 by the control valves 7 and 8 on the back, in the case of fluctuation based on the disturbance of the circulating pressure or circulating rate of the burning air at the furnaces 1 and 2 or the change of setting, the number of revolution of the fan of the fan devices 5B and 6B is controlled so as to set the circulating pressure and the circulating rate in a control range by fuzzy inference respectively integrating the states of the opening degrees of the control valves 7 and 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of devices, each of which is provided with combustion air at a pressure or a flow rate corresponding to the individual pipes.
It is applied to a merging pipeline system in which a fluid such as water is supplied and the fluid in each individual pipeline is merged by one merging pipeline in the rear of each device to flow backward at a predetermined pressure or flow rate. The present invention relates to a fan rotation speed control method for a merging conduit system that controls the pressure or flow rate of fluid in each individual conduit.

[0002]

2. Description of the Related Art Conventionally, a refuse incineration facility is provided with a plurality of combustion furnaces, ash melting furnaces, etc., and combustion air of each furnace is supplied by a confluent conduit system shown in FIG. FIG. 4 shows a configuration in the case where two furnaces 1 and 2 are provided as supply target devices, and 3 and 4 are individual conduits for the furnaces 1 and 2, respectively, and input conduits 3a of the furnaces 1 and 2, respectively.
4a and output lines 3b, 4b.

5A and 6A are supply side fan devices provided in the input pipe lines 3a and 4a, 7 and 8 are control valves for pressure adjustment provided in the output pipe lines 3b and 4b, and 9 and 10 are control valves 7. ，
8 is a pressure controller having a PID structure for feedback control, 11 is one merging conduit connected to the output conduits 3b and 4b, and 12 is a discharge side fan device provided in the merging conduit 11. Then, the fan devices 5A and 6A operate at preset fan rotation speeds, respectively, and burn the combustion air having a blowing pressure determined by the rotation speeds through the input pipe lines 3a and 4a.
Supply to 2.

Further, the used combustion air that has passed through the furnaces 1 and 2 is sent to the merging conduit 11 via the output conduits 3b and 4b, merges in this conduit 11 and flows further rearward. At this time, in order to control the combustion air of the furnaces 1 and 2 to a set pressure, the combustion air as the controlled amount of the furnaces 1 and 2 is controlled by a pressure sensor (not shown) provided in each of the furnaces 1 and 2. Is constantly detected, and pressure detection signals S1i and S2i of both pressure sensors proportional to the pressure are supplied to the controllers 9 and 10, respectively.

The controllers 9 and 10 are supplied with the pressure detection signals S1i and S2i as well as the pressure setting signals S1r and S2r at the terminals 13 and 14, respectively, so that the signals S1i and S2i coincide with the signals S1r and S2r, respectively.
The control signals S1x and S2x of the valve opening degrees that change according to S1i and S2r-S2i are formed and supplied to the control valves 7 and 8. Then, based on the control signals S1x and S2x,
The valve openings of the control valves 7 and 8 are feedback-controlled so that the pressures of the combustion air in the furnaces 1 and 2 become the pressures of the pressure setting signals S1r and S2r, respectively. In addition, the fan device 12
Operates at the set fan rotation speed, and the combustion air after the merging of the merging conduits 11 is discharged backward and sent at a pressure based on this rotation speed.

[0006]

In the case of the conventional merging conduit system shown in FIG. 4, the combustion air is supplied to the individual conduits 3 and 4 at a constant value based on the fan speed of each of the fan devices 5A and 6A. Since the discharge of the combustion air from the merging conduit 12 is fixed and fixed to a constant value based on the fan rotation speed of the fan device 12, one of the two is determined based on fluctuations due to disturbance of the furnace 1 or 2 and changes in combustion conditions. When a change or change in the valve opening of the control valve 7 or 8 or the fan speed of the fan device 5A or 6A occurs in the individual pipes 3 or 4, when the change or change occurs, the flow pressure of the combustion air or the flow rate of the combustion air changes. Changes in the other individual pipeline 4 or 3
To act as a change in the back pressure from the output pipeline 4b or 3b, and the flow pressure and flow rate of the combustion air change not only in the one individual pipeline 3 or 4 but also in the other individual pipeline 4 or 3.

Further, when the valve opening of the control valve 8 or 7 of the other individual conduit 4 or 3 changes with this change, the change in the flow pressure or flow rate of the combustion air due to this change changes. It acts on the individual conduits 3 or 4 as a change in back pressure from the output conduits 3b or 4b, and the valve opening of the control valve 7 or 8 changes.
After that, the valve openings of the control valves 7 and 8 are repeated until the flow pressure and flow rate of the combustion air in the individual pipe lines 3 and 4 converge to a stable state and fluctuations in the combustion air in the furnaces 1 and 2 are suppressed. Controlled.

Then, the flow pressure and flow rate of the combustion air in one individual pipeline 3 or 4 and the flow pressure and flow rate of the combustion air in the other individual pipeline 4 or 3 are changed in relation to each other. Therefore, due to repeated changes in the valve opening of the control valves 7 and 8, the flow pressure and flow rate of the combustion air in the individual pipe lines 3 and 4 may change in the diverging direction in some cases, and finally the feedback control There is a problem that it falls out of range and falls out of control. Although FIG. 4 illustrates the case where the number of the individual pipelines is two, the same problem occurs even when the number of the individual pipelines is three or more.

The same problems as described above also occur when various gases or liquids other than combustion air are supplied to each supply target device. SUMMARY OF THE INVENTION It is an object of the present invention to prevent disturbance of a controlled amount such as a flow pressure and a flow rate of a fluid such as combustion air of a supply target device provided in each individual pipeline, and uncontrollability due to a setting change. ..

[0010]

In order to achieve the above-mentioned object, in the method for controlling the number of rotations of a fan in a merging conduit system according to the present invention, disturbance of a controlled amount of fluid in each supply device and setting change. , Etc., the fan rotation speed of the supply side fan device of each individual pipeline is determined by fuzzy reasoning that integrates the state of the valve opening of the control valve of each individual pipeline. The control amount is controlled so as to be drawn within the control range.

[0011]

In the fan rotation speed control method of the merged conduit system of the present invention configured as described above, the fan rotation speeds of the supply side fan devices of the individual conduits are all determined by fuzzy inference. Is set variably in consideration of the valve opening of the control valve, and the supply of fluid to the controlled device in each individual line absorbs the disturbance of the controlled amount of the fluid in one of the lines and the fluctuation due to the setting change. The valve opening of each control valve is always maintained within the control range.

[0012]

EXAMPLE One example will be described with reference to FIGS. 1, the same reference numerals as those in FIG. 4 indicate the same or corresponding ones, except that a fuzzy inference control device 15 of a microcomputer configuration to which the control signals S1x and S2x of the valve opening are supplied is added. In place of the fan devices 5A and 5B, the supply side fan devices 5B and 6B whose fan rotation speed is variably controlled by the control device 15 are provided.

Then, the control signals S1x, S2x of the valve opening degrees supplied from the controllers 9, 10 to the control valves 7, 8 are also supplied to the control device 15, and the control device 15 performs control based on the control signals S1x, S2x. The appropriate fan rotation speeds of the fan devices 5B and 6B are fuzzy inferred using the valve openings of the valves 7 and 8.

Next, the fuzzy inference of the control device 15 will be described. In order to simplify the explanation, assuming that the pipeline system of the individual pipeline 3 is the A system and the pipeline system of the individual pipeline 4 is the B system, the valve opening degree of the control valves 7 and 8 in the control device 15 is S (small. ), M
Membership functions having the shapes of (a) and (b) of FIG. 2 classified into three sets (adaptation) and L (large) are set.

The control device 15 then controls the control signals S1x,
Regarding the actual valve opening of the control valves 7 and 8 obtained from S2x,
The set to which it belongs and the matching value (grade value) are obtained from the functions of (a) and (b) of FIG. By the way, in the case of this embodiment, the control valves 7 and 8 are feedback-controlled by the controllers 9 and 10 so that the flow pressure of the combustion air in the furnaces 1 and 2 as the supplied devices becomes the pressure of the pressure setting signals S1r and S2r. To be done. Then, during normal operation, the control valves 7, 8
Both of the valve openings are within the set M conforming range.

However, when the pressure of the combustion air flowing through the furnaces 1 and 2 fluctuates due to disturbance or set fluctuations, the valve opening degrees of the control valves 7 and 8 change in the direction out of the compatible range. This change is caused by pressure fluctuations of the system to which the control valves 7 and 8 belong (fluctuations of the own system) and pressure fluctuations of other systems that do not belong (variation of the other system).

For example, when the pressure of the combustion air flowing through the furnace 2 is reduced by disturbance, the pressure of the B system decreases and fluctuates, and at the same time, the back pressure of the control valve 7 decreases and the pressure of the combustion air flowing through the furnace 1 decreases. Becomes smaller, and the pressure in the A system also decreases and fluctuates. At this time, if the fan rotation speed of the fan device 5B is increased in accordance with the valve opening of the control valve 8 and the combustion air in the furnace 1 is increased in accordance with the decrease in the back pressure of the control valve 7, the air flows through the furnace 1. Fluctuations in the valve opening of the control valve 7 are prevented by compensating for other system fluctuations in the combustion air pressure.

Further, the fan rotation speed of the fan device 6B is reduced in accordance with the valve opening of the control valve 8 to control the control valve 8 due to disturbance.
When the amount of combustion air in the furnace 2 is reduced in accordance with the variation in the valve opening degree, the self-system variation is compensated, and unnecessary variation after the end of the disturbance is prevented.

Therefore, the control unit 15 of FIG. 2 (c) for determining the optimum values of the fan rotation speeds of the A system (self system) and the B system (other system) based on the valve opening of the control valve 7. (D) and (d) in the same figure for determining the optimum values of the fan speeds of the B system (self system) and the A system (other system) based on the membership function of (e) and the valve opening of the control valve 8. The membership function of f) is set. 2 (c) to 2 (f), the lower part is shown as a set, the current state is left as it is, and the upper part is shown as a little.

Then, based on the control signals S1x and S2x, the control valves 7 and 8 are opened, for example, in the valve opening X of FIGS. 2 (a) and 2 (b).
When detected as a, Xb, the valve opening degrees Xa, Xb are the opening degrees of the conformity of 0.5 for each of the sets M, S, so that A
Regarding the system, the current conditions (c) and (d) in the same figure, and the point of the degree of conformity of 0.5 above are the points of fan speeds Pa and Pb obtained from the own system and the other system, respectively. Further, based on the fan rotational speeds Pa and Pb obtained from the self system and the other system, the control device 15 infers and determines the optimum value of the fan rotational speeds of the fan devices 5B and 6B by, for example, the center of gravity method.

That is, the control valves 7 and 8 are shown in FIG.
In the case of the valve openings Xa and Xb of (b), the control device 15 obtains the center of gravity of the triangles (c) and (d) of the same figure, and determines the point P1 of the center of gravity shown in FIG. 3 as the fan rotation of the fan device 5B. Determine as a number.

Then, control signals S1y and S2y for the rotation speeds are supplied from the control device 15 to the fan devices 5B and 6B so that the determined fan rotation speed is reached, and the fan rotation speeds of the fan devices 5B and 6B based on this supply are supplied. As a result of the control, the amount of combustion air supplied to the furnaces 1 and 2 causes disturbances in its own system and other systems,
It is automatically variably adjusted in consideration of the pressure fluctuation based on the setting change, and the valve openings of the control valves 7 and 8 are always kept within the conforming range of the set M, so that the control cannot be lost.

In the above embodiment, the present invention is applied to the collecting pipeline system having the two individual pipelines 3 and 4, but the same applies to the collecting pipeline system having three or more individual pipelines. be able to. The supplied device may be other than the furnaces 1 and 2, and in this case, the fluid supplied to each supplied device may be either a gas or a liquid.

Furthermore, the method of fuzzy inference such as the shape of each membership function is not limited to the embodiment. Further, in the above-described embodiment, it is applied when the flow pressure of each individual pipeline is feedback-controlled by the control valves 7 and 8. However, it is of course applicable to the case where the flow rate of each individual pipeline is feedback-controlled. is there.

[0025]

Since the present invention is configured as described above, it has the following effects. The fan speeds of the supply-side fan devices 5B and 6B of the individual pipelines 3 and 4 are determined by fuzzy inference that integrates the states of the valve opening degrees of the control valves 7 and 8 and variably controlled, and the individual pipelines are controlled. The supply of fluid to the supply devices (furnace 1 and 2) of 3 and 4 is automatically performed so as to absorb the disturbance of the controlled amount of the fluid of one of the pipelines 3 and 4 and the fluctuation due to the setting change. Because of the adjustment, each control valve 7,
The valve opening of No. 8 is always kept within the control range and does not fall out of control, the control performance is remarkably improved, and each supplied device is stably operated.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a method for controlling a fan rotation speed of a merged conduit system of the present invention.

2A to 2F are explanatory views of a membership function set in the control device of FIG.

FIG. 3 is an explanatory diagram for determining a fan rotation speed of the control device of FIG.

FIG. 4 is a block diagram of a conventional example.

[Explanation of symbols]

 1, 2 furnaces 3, 4 individual pipe lines 5B, 6B supply side fan device 7, 8 control valve 11 merging pipe line 12 discharge side fan device 15 control device

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G05D 13/62 N 7361-3H 16/20 A 7314-3H

Claims (1)

Claim: What is claimed is: 1. A supply-side fan, which is provided on the input side of each individual conduit as a fluid passage for each supply-target device, and which supplies the fluid to each supply-target device in accordance with the fan rotation speed. A valve is opened so that a controlled amount, which is provided by the device and the output side of each of the supplied devices of each of the individual pipelines, which is the flowing pressure or the flow rate of the fluid in each of the supplied devices, has a predetermined value. A control valve whose degree is controlled, and a fluid that is connected to each of the individual pipelines behind each of the control valves and is provided in a merging pipeline in which the fluid of each of the individual pipelines merges, at a set fan rotation speed. In a merging conduit system including a discharge-side fan device that discharges backward, when the fluctuation occurs due to disturbance of the controlled amount of the fluid in each of the supply-target devices, setting change, etc., the fan of each supply-side fan device The number of revolutions of the valve opening of each control valve The fuzzy inference obtained by integrating the state, the fan speed control method of the confluence pipe system and controlling such that each controlled quantity is drawn within the control range.