JP2019078503A - Enclosed hood device and exhaust air quantity control method thereof - Google Patents

Abstract

To provide an enclosed hood device capable of simply and inexpensively attaining suitable followability of exhaust air quantity to opening/closing of a door, and an exhaust air quantity control method thereof.SOLUTION: An enclosed hood device comprises a space S enclosed by a wall 3 and a door 4, an exhaust pipe 6 through which exhaust from the space S circulates, and a fan 5 configured to perform air exhaustion from the space S through the exhaust pipe 6. An exhaust air quantity control method of the enclosed hood device comprises: providing a damper 7 in the middle of the exhaust pipe 6, wherein the damper can operate its opening; executing feedback control of adjusting the opening of the damper 7 so that an actual pressure value on an upstream side of the damper 7 in the exhaust pipe 6 approaches a setting pressure value calculated based on opening of the door 4; and when opening/closing operation is applied to the door 4, executing feed forward control of performing a predetermined operation amount of opening operation for the damper 7.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for controlling the exhaust air flow rate of an enclosure type hood device used for handling chemicals etc., and an enclosure type hood device to which the same is applied.

  Conventionally, when handling organic solvents, chemicals and the like, an enclosed hood apparatus may be used for the safety of workers. The enclosure type hood device is a device that encloses a predetermined space such as on a workbench and exhausts the space, and is also called a local exhaust system, a draft chamber, a fume hood or the like. A part of the enclosure is a door that opens and closes up and down, and the worker performs work by inserting an arm from the opening below the door onto the work bench. Since the air is exhausted from the space inside the enclosure, even if a harmful gas or the like is generated from a chemical or the like placed in the space, it can be discharged from the space. In addition, since an air flow from the outside toward the space is generated at the opening of the door with the exhaust, a situation in which gas or the like in the space leaks from the opening to the outside is prevented.

  Here, with regard to the wind passing through the opening at the opening, the required wind speed is defined by the material to be handled, and the passing wind speed must be maintained at a certain level or more regardless of the opening of the door.

  The passing wind speed at the opening is determined by the amount of exhaust air from the space and the area of the opening, that is, the opening degree of the door. Therefore, in order to maintain a predetermined passing wind speed, it is necessary to change the exhaust air volume according to the opening degree of the door.

  On the other hand, opening and closing of the door is performed by an operator in a short time of less than one second to at most several seconds, and the opening degree of the door usually changes rapidly. For this reason, a mechanism is required which rapidly changes the exhaust air flow rate so that the predetermined passing wind speed can be maintained even if the opening of the door suddenly changes.

  As a prior art document relevant to such a wind volume control, there exist following patent document 1 grade | etc.,.

Unexamined-Japanese-Patent No. 2010-223540

  For the air volume control in the above-mentioned enclosure type hood device, for example, a variable air volume device provided with a variable opening type blade is used. However, this kind of variable air volume device itself is an expensive device having a complicated mechanism, and it is necessary to keep high differential pressure before and after the variable air volume device in order to fully exert the function of air volume control. However, the running cost is increased due to the pressure loss.

  SUMMARY OF THE INVENTION In view of such circumstances, the present invention is intended to provide an enclosed hood apparatus and an exhaust air flow rate control method capable of realizing a suitable follow-up property of the exhaust air flow rate to the opening and closing of a door simply and at low cost.

  The present invention relates to an exhaust air flow control of an enclosure type hood apparatus including a space surrounded by a wall and a door, an exhaust pipe through which exhaust gas from the space flows, and a fan exhausting the space from the space through the exhaust pipe. In the method, a damper capable of operating the opening degree is provided in the middle of the exhaust pipe, and a measured pressure value on the upstream side of the damper in the exhaust pipe is a set pressure value calculated based on the opening degree of the door. The feedback control for adjusting the opening degree of the damper is performed so as to be closer, and the feedforward control for performing the opening degree operation of a predetermined operation amount on the damper when the opening / closing operation is applied to the door is performed. The present invention relates to a method of controlling an exhaust air flow rate of an enclosed hood device characterized by the following.

  In the method of controlling the exhaust air volume of the enclosed hood device according to the present invention, the operation amount of the opening operation performed on the damper in the feedforward control is the opening and closing of the door while executing the feedback control in the enclosed hood device. It can be determined based on the amount of change in the opening degree of the damper when an operation is performed.

  In the method of controlling the exhaust air flow rate of the enclosed hood device according to the present invention, the exhaust pipes of a plurality of the enclosed hood devices are merged, and the feedback control and the feedforward control are performed in each enclosed hood device. With respect to the damper of the enclosure type hood device, it is possible to execute feedforward control that performs the opening degree operation of a predetermined operation amount when the opening and closing operation is applied to the door of another enclosure type hood device.

  In the exhaust air flow control method of the enclosure type hood device of the present invention, the opening degree of the damper in the feedforward control executed by the one enclosure type hood device with the opening and closing operation of the door of the other enclosure type hood device. The operation amount is the opening degree of the damper of the one enclosed hood device when the opening and closing operation of the door of the other enclosed hood device is performed while performing the feedback control in the one enclosed hood device. It can be determined based on the amount of change.

  Further, according to the present invention, the space surrounded by the wall and the door, the exhaust pipe through which the exhaust gas from the space flows, the fan for exhausting the space, and the opening degree in the middle of the exhaust pipe can be manipulated. A damper installed, an opening degree sensor for detecting the opening degree of the door, and a pressure sensor for detecting the pressure in the exhaust pipe on the upstream side of the damper, and measurement on the upstream side of the damper in the exhaust pipe The feedback control for adjusting the opening degree of the damper is performed so that the pressure value approaches the set pressure value calculated based on the opening degree of the door, and the damper is opened and closed when the door is opened or closed. On the other hand, the present invention relates to an enclosed type hood apparatus which is configured to execute feedforward control for performing an opening operation of a predetermined operation amount.

  In the enclosed hood device according to the present invention, exhaust pipes of a plurality of the enclosed hood devices join, and each enclosed hood device performs the feedback control and the feed forward control, and one enclosed hood device The damper can be configured to execute feedforward control that performs an opening operation of a predetermined operation amount when an opening / closing operation is applied to the door of another enclosed hood device.

  According to the enclosed type hood device and the exhaust air flow rate control method of the present invention, it is possible to achieve an excellent effect that a suitable follow-up property of the exhaust air flow rate to the opening and closing of the door can be realized simply and at low cost.

FIG. 1 is a schematic view showing an embodiment of an enclosed hood device according to a first embodiment of the present invention. It is a graph explaining an example of a relation of a coefficient of resistance of air which passes an enclosure type hood device, an opening of a door, and a degree of damper opening. It is a graph explaining an example of a relation between a difference between a set pressure value and an actual measurement pressure value and an operation amount of an opening operation applied to the damper regarding feedback control of the damper opening. It is a flow chart explaining an example of a procedure of feedback control to a damper opening. It is a graph explaining an example of opening degree operation added to a damper in feedforward control of damper opening degree. It is a flowchart explaining an example of a procedure of feedforward control to damper opening. In the first embodiment of the present invention, it is a graph for explaining an example of the fluctuation of the differential pressure accompanying the opening operation of the door. A graph for explaining an example of variations in differential pressure and damper opening degree accompanying the opening operation of the door when only feedback control is performed in one step of a test for determining the operation amount of damper opening degree in feed forward control is there. It is a graph explaining an example of change of differential pressure in another process of a test for determining the operation amount of the damper opening in feedforward control. It is a flowchart explaining an example of the procedure of the test for determining the operating quantity of the damper opening degree in feedforward control. FIG. 5 is a schematic view showing an embodiment of an enclosed hood device according to a second embodiment of the present invention. It is a graph explaining an example of change of differential pressure in a 2nd example of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the attached drawings.

  FIG. 1 shows an example of the form of the enclosed food | hood apparatus by implementation of this invention. The enclosure-type hood device 1 of the first embodiment forms a space S surrounded by the wall 3 and the door 4 above the work table 2. An exhaust pipe 6 is connected to the upper side of the space S, and the gas in the space S is exhausted by a fan 5 provided on the downstream side of the exhaust pipe 6. A damper 7 provided with a motor 7a is disposed at a position upstream of the fan 5 of the exhaust pipe 6, and the amount of exhaust air in the exhaust pipe 6 is adjusted by changing the opening degree of the damper 7 by the operation of the motor 7a. It can be done. The opening degree of the damper 7 is controlled in accordance with the operation signal 7 b input from the controller 8 to the motor 7 a.

  The opening degree of the door 4 corresponding to the front surface of the enclosure type hood device 1 is detected by the opening degree sensor 9 and is input to the control device 8 as an opening degree signal 9a. Further, a pressure sensor 10 is installed at a position upstream of the damper 7 in the exhaust pipe 6 so as to detect the pressure in the exhaust pipe 6 as a pressure difference with the outside. The detected value of the pressure sensor 10 is input to the control device 8 as a pressure signal 10a.

  Next, the operation of the first embodiment described above will be described.

When the enclosure type hood device 1 is in operation, the exhaust air flow rate is controlled by adjusting the opening degree of the damper 7. The actual exhaust air flow volume (actual air flow volume) exhausted from the space S through the exhaust pipe 6 is obtained by the following equation.
[Equation 1]
ΔP = ξ × ρu ^2/2
[Formula 2]
Q = 3600 × Av
[Equation 3]
Q = 3600 × Bu
[Equation 4]
ξ = a × e ^bA

A is the area [m ² ] of the opening of the door 4 and is obtained from the detection value of the opening sensor 9. B is the cross-sectional area [m ² ] of the exhaust pipe 6 and is a constant. ΔP is a pressure value obtained as a detection value of the pressure sensor 10 and is a differential pressure [Pa] between the inside of the exhaust pipe 6 and the outside. ρ is the density of air [kg / m ³ ] and is a constant. Q is the air volume of the exhaust flowing in the exhaust pipe 6 [m ³ / h], u is the wind speed of the wind flowing through the exhaust pipe 6 [m / s], v is the wind speed of the wind passing through the opening of the door 4 [m / S]. The wedge is a coefficient of resistance when air passes through the enclosure type hood device 1 and is a function of the opening degree of the door 4 and the opening degree of the damper 7 (referred to as the damper opening degree θ). The resistance coefficient ξ has a relationship as shown in FIG. 2 with respect to the opening degree of the door 4 and the damper opening degree θ, for example. Then, such a relationship is measured in advance by the actual machine of the enclosure type hood device 1 to determine the coefficient a and the index b of the above equation 4 under each condition, and input to the control device 8 as a function or a table. Can be calculated from the opening degree of the door 4 and the damper opening degree θ.

  When the fan 5 operates with a constant output and the opening degree of the door 4 and the damper opening degree θ are constant, the values of u and v and the values of Q, ΔP and ξ are constant. Here, when the operator applies the opening and closing operation to the door 4, the opening area at the door 4 changes, so the exhaust air volume (set air volume) required for the enclosure type hood device 1 fluctuates, and the actual air volume is the set air volume Disagree with. At the same time, the actual measured value of the differential pressure ΔP, the actual wind speed u, v and the air volume Q also change under the influence. Therefore, in order to eliminate the deviation between the actual air volume and the set air volume, it is necessary to adjust the air volume Q by operating the damper opening degree θ.

  In the first embodiment, the required differential pressure ΔP calculated from the set air volume (referred to as the set pressure value SP) and the value of the differential pressure ΔP detected by the pressure sensor 10 (referred to as the measured pressure value PV) The feedback control is performed on the opening degree of the damper 7 based on the above. Specifically, the control device 8 first determines the set pressure value SP. The set pressure value SP can be calculated using the opening degree of the door 4 obtained from the opening degree sensor 9 and the set air volume according to the above formulas 1 to 4. Then, for example, as shown in FIG. 3, the damper opening degree θ is adjusted according to the difference between the set pressure value SP and the measured pressure value PV. If the value of SP-PV is positive (that is, the measured pressure value PV is smaller than the set pressure value SP), the damper opening degree θ is increased, and if the value of SP-PV is negative (that is, the setting If the measured pressure value PV is larger than the pressure value SP, the damper 7 is operated to reduce the damper opening degree θ. The operation amount of the damper 7 is increased as the absolute value of SP-PV is larger. Thus, the damper opening degree θ is adjusted so that the measured pressure value PV approaches the set pressure value SP. This adjustment operation is performed until the measured pressure value PV converges to the vicinity of the set pressure value SP, and when the measured pressure value PV falls within a predetermined range with respect to the set pressure value SP (for example, the measured pressure value PV is the set pressure value) When the measured pressure value becomes 0.9 times or more and 1.1 times or less of SP or the measured pressure value PV matches the set pressure value SP), the operation of the motor 7a is stopped. As a result, the damper opening degree θ, the differential pressure ΔP, and the actual air volume are settled. Here, the control is exemplified such that the manipulated variable of the damper opening degree θ is proportional to the value of SP-PV, but this is an example, and the opening degree control of the damper 7 is usually used as feedback control. The method of can be used suitably.

  The procedure concerning such feedback control is represented by a flowchart as shown in FIG. First, at step S1, a set pressure value SP is calculated from the detected value of the opening sensor 9 and the set air volume. In step S2, the measured pressure value PV is acquired as the detection value of the pressure sensor 10, and in step S3, the set pressure value SP is compared with the measured pressure value PV. If the measured pressure value PV is within the predetermined range with respect to the set pressure value SP, the operation of the motor 7a is stopped in step S4, and the process returns to step S1. In step S3, when the measured pressure value PV is out of the predetermined range with respect to the set pressure value SP, the process proceeds to step S5, the motor 7a is operated according to the value of SP-PV, and the opening degree of the damper 7 Are adjusted and the process returns to step S1 again. Thus, the adjustment of the opening of the damper 7 is repeated until the settling time is reached.

  In addition to the feedback control as described above, in the first embodiment, feedforward control is performed on the damper 7 in accordance with the detection value of the opening degree sensor 9. This feed forward control is to change the damper opening degree θ promptly by a predetermined amount when the door 4 is subjected to opening / closing operation of a certain size or more.

  Feed forward control is executed when the change in the opening degree of the door 4 within a predetermined time is equal to or greater than a predetermined value. Here, the “predetermined time” is an appropriate value, for example, 0.5 seconds to 3 seconds, and the “predetermined value” regarding the opening change of the door 4 is an appropriate value, for example, 20% to 100%. It is. Then, the opening degree of the door 4 is grasped every moment as the opening degree signal 9a from the opening degree sensor 9 in the control device 8. For example, when the opening degree is increased by 50% or more in one second or less, the door It is determined that the opening operation of 4 is detected, and the opening operation of a predetermined angle is performed on the damper 7 to increase the air volume (see FIG. 5). On the contrary, when the closing operation of the door 4 is detected, that is, when the opening degree decreases by 50% or more within 1 second, the air volume is reduced by closing the damper 7 by a predetermined angle. Let The feedforward control may be performed only when the door 4 is opened, and may not be performed when the door 4 is closed.

  A procedure relating to feedforward control is represented by a flowchart as shown in FIG. As step S11, the opening degree of the door 4 is acquired from the detection value of the opening degree sensor 9. In step S12, it is determined whether the opening degree of the door 4 has changed by a predetermined value or more between a predetermined time before and the present time. If the change amount of the detection value of the opening degree sensor 9 from before the predetermined time to the present time is less than the predetermined value, the process returns to step S11. If the change amount is equal to or more than the predetermined value, the process proceeds to step S13, and the opening degree operation of the damper 7 as shown in FIG. 5 is performed. After operating the opening degree of the damper 7, the process returns to step S11, and the following steps are repeated.

  When the enclosed hood device 1 is in operation, the controller 8 executes the feedback control (see FIGS. 3 and 4) and the feedforward control (see FIGS. 5 and 6) in parallel. By doing this, it is possible to carry out an operation with a quick air volume and to significantly reduce the time until settling.

  The change of the differential pressure ΔP when assuming that only feedback control is performed is shown by a broken line in FIG. When the door 4 has a certain degree of opening, the actual air volume, the differential pressure ΔP, and the damper opening θ are settled to predetermined values by feedback control. From this state, for example, when the door 4 is pulled open, the set air volume increases and the set pressure value SP calculated from the set air volume increases, and the feedback control is performed until the measured pressure value PV reaches around the set pressure value SP. The damper 7 is operated. The differential pressure ΔP rises over time as shown by the broken line, and is settled when the measured pressure value PV rises to near the required pressure value SP. Although not shown, when the closing operation for pulling down the door 4 is performed, the measured pressure value PV drops to the vicinity of the set pressure value SP, and the differential pressure ΔP is settled. Show. Here, for convenience of explanation, the fluctuation of the differential pressure ΔP is illustrated as a smooth line, but in actuality, the value of the differential pressure ΔP finely moves up and down finely (see FIG. 8 and FIG. The same applies to the differential pressure ΔP and the damper opening θ shown in FIG.

  As described above, in feedback control in which fine adjustment is repeated while monitoring actual measurement values, it takes time to settle the differential pressure ΔP and the actual air volume. That is, after the opening / closing operation of the door 4, the actual air volume will deviate from the set air volume for a while. In the first embodiment, therefore, feedforward control is performed in addition to feedback control (see FIGS. 5 and 6) to significantly reduce the time until settling. As described above, in the feedforward control, when the opening / closing operation of the door 4 is detected, the immediate damper opening degree θ is operated. As a result, immediately after the opening and closing operation is detected, the damper 7 is operated to near the opening degree (hereinafter referred to as the “target opening degree”) in the finally settled state. That is, if feedback control is used alone, the damper 7 takes time for fine adjustment and is operated to the damper opening degree θ in the settling state, but the damper opening degree θ is obtained by instantaneously applying the opening degree operation by feedforward control. Is operated quickly to near the target opening.

  Thus, by combining feedforward control with feedback control, rapid settling as shown by a solid line in FIG. 7 becomes possible. If a high speed motor is used as the motor 7a for driving the damper 7, the time until settling can be suppressed to within 1 second.

  At this time, the opening sensor 9 functions as an opening detection mechanism that detects the opening of the door 4 in feedback control, and also functions as an opening / closing operation detection mechanism that detects the opening / closing operation of the door 4 in feedforward control. become. As described above, by sharing the opening degree sensor 9, it is possible to combine feedforward control with feedback control with a simple configuration without adding a special configuration.

  Here, in the case of feed forward control, since the damper opening degree θ is not calculated based on the opening degree of the door 4 each time to operate the damper 7, the damper open degree by feed forward control does not necessarily reach the vicinity of the target opening exactly. For example, when the door 4 is opened to a smaller size (that is, to a degree slightly larger than the “predetermined value” which is a threshold value for performing feedforward control), the damper opening θ necessary for the size of the opening operation By applying an operation larger than the operation amount to the damper 7 by feedforward control, the opening degree of the damper 7 becomes larger than the target opening degree, and an overshoot may occur in which the actual air volume exceeds the set air volume. Conversely, when the operation amount of the damper opening degree θ by feedforward control is less than the required operation amount with respect to the operation amount of the door 4, the opening degree of the damper 7 becomes smaller than the target opening degree, and the set air volume The actual wind volume is less than the undershoot.

  When overshoot or undershoot occurs, the damper opening degree θ is finely adjusted by feedback control, and eventually settled near the target opening degree. Then, if the amount of overshoot or undershoot is not excessive, the damper opening degree θ immediately after the feedforward control approaches the target opening degree as compared to the case where the feedforward control is not performed, so the settling time is also constant. Time is shortened.

  However, if the amount of overshoot or undershoot during feedforward control is too large, it takes time to operate the damper 7 to the target opening degree by feedback control from there. Therefore, it is necessary to adjust the amount of operation of the damper opening degree θ in feedforward control to an appropriate amount in advance so that the amount of overshoot or undershoot does not become excessive.

Operation of the damper opening degree θ in the feed forward control (the operation amount X ₁₎ can be determined by performing a test such as by following such instructions. The actual machine (see FIG. 1) of the enclosure type hood device 1 is operated, and the control device 8 causes the damper 7 to execute the above-described feedback control (see FIGS. 3 and 4). If the door 4 is set to the minimum opening degree in this state, the actual air volume, the measured pressure value PV, and the damper opening degree θ are settled to predetermined values by feedback control. From there, when the door 4 is pulled up to the maximum opening degree, the set air volume increases, and as shown in FIG. 8, the damper opening degree θ is gradually adjusted largely by feedback control (see broken line) and the differential pressure ΔP gradually rises The differential pressure ΔP is settled when the measured pressure value PV reaches near the set pressure value SP (see the solid line).

Then, based on the amount of change in the damper opening degree θ (referred to as X ₀ ) after the door 4 is opened and the differential pressure ΔP is settled by feedback control, the operation of the damper opening degree θ in feedforward control Determine the quantity X ₁

However, the change amount X ₀ can not necessarily be adopted as the operation amount X ₁ as it is. The variation X ₀ obtained in the feedback control as described above, when it is used as a manipulated variable X ₁ in the feedforward control in step S13 (see FIG. 6), since a large overshoot or undershoot may occur following Further fine-tune in the procedure of

The actual machine of the enclosure type hood device 1 is operated, and the control device 8 performs feedforward control (see FIGS. 5 and 6) in addition to the feedback control described above (see FIGS. 3 and 4). With the door 4 set to the minimum opening degree, the actual air volume, the differential pressure ΔP, and the damper opening degree θ are settled. From this state, when the door 4 is pulled up to the maximum opening degree, feedforward control is executed. At this time, the change amount X ₀ obtained above is used as the operation amount X ₁ of the damper 7 by feedforward control. Here, if the damper opening degree θ operated by the change amount X ₀ is eventually close to the value of the damper opening degree θ at the time of settling, as shown by the solid line in FIG. Settled. On the other hand, the change amount X _0, if too large as the operation amount X ₁ of the damper opening θ for the opening operation of the door 4 occurs overshoot Jitsukazeryou as indicated by a broken line, the undershoot as shown by a chain line if too small This causes an operation delay that takes time to settle.

Overshoot and undershoot do not cause any problem because they are settled by feedback control without much time if there is within a certain range, but if overshoot or undershoot is large, a damper used for feedforward control 7 values of the manipulated variables X ₁ of (shorter time to settle) from the change amount X ₀ overshoot or undershoot is reduced direction is appropriately increased or decreased, the door 4 to open at the enclosure hood device 1 again Test to operate and perform feedback control and feedforward control. These steps may be repeated to finally determine the operation amount X ₁ to be adopted.

In this case, although just optimal operation amount X ₁ in the course of repetition may be adopted that value as long even people obtained, is troublesome takes to repeat many times the test until an optimal operation amount X ₁ is obtained. Therefore, an operation amount X ₁ when the overshoot occurs, may be adopted as appropriate acceleration amounts as the final manipulated variable X ₁ in accordance with the degree of overshoot. That is, once it after performing the test by setting the operation amount X ₁ to be slightly overshoot slightly, to the operation amount after adjusting in accordance with the result of the test the final operation amount X _1. Thus, while eliminating the need to repeat the test many times, it is possible to adjust the operation amount X _1.

Alternatively, (and alpha) a predetermined amount in the change amount X ₀ of the damper opening degree θ to the settling Jitsukazeryou may be the final operation amount X ₁ The amounts added. That is, X ₁ = X ₀ + α. At this time, the value of the predetermined amount α is set to, for example, variation 1 or more and change amount X than ₀ and 10 minutes of X _0. In this case, although the operation of the damper 7 every time the opening operation of the door 4 is in the slightly overshoot Pounds, procedure according to the adjustment of the operation amount X ₁ is greatly simplified or unnecessary.

Note that, although described test procedures as an example, a case of opening the door 4 from minimum to maximum, even if you run a feed-forward control during the closing operation of the door 4, determines the operation amount X ₁ by the same procedure (At this time, changes as shown in FIG. 8 and FIG. 9 are upside down).

Also, the optimum value as the operation amount X ₁ strictly depends on the size of the opening / closing operation applied to the door 4. Therefore, for example, in the above-described test, the variation X ₀ is acquired under a plurality of conditions for the opening and closing operation of the door 4 and in the feedforward control, the operation amount X different according to the detected opening and closing amount of the door 4 _It may be set to ₁ . However, repeating the above test many times under a plurality of conditions in this way is very complicated. In addition, when the enclosure type hood device 1 is used, the door 4 is not often finely opened and closed. Even if it is fine, if it is fine opening and closing, adjustment by feedback control only can correspond sufficiently. Therefore, usually, the above tests will get only the change amount X ₀ under the condition of changing the maximum opening of the door 4 from the minimum or the maximum, to the minimum, and appropriately increase or decrease the amount of change X ₀ Subsequent adjustment It seems that the procedure of setting the amount of operation to the operation amount X ₁ is sufficient. However, when actually operating the enclosure type hood apparatus 1, if overshoot or undershoot occurs frequently or excessively depending on the size of the opening / closing operation when opening / closing the door 4, for example, the operation amount of the door 4 Of course, a plurality of values may be used as the operation amount X ₁ according to the above.

The test procedure in accordance with the determination of such an operation amount X ₁ described above is illustrated in the flow chart as shown in FIG. 10 for example. In step S21, only the feedback control is performed by the enclosure type hood device 1, and the opening / closing operation of the door 4 (for example, the opening operation from the minimum opening degree to the maximum opening degree) is performed. Next, in step S22, it calculates a change amount X ₀ of the damper opening degree θ to the settling Jitsukazeryou. In step S23, while the feedback control and the feedforward control are performed by the enclosure type hood device 1, the opening and closing operation of the door 4 is performed. The operation amount X ₁ at the time of feed-forward control, using the change amount X ₀ obtained in step S22. As step S24, the presence or absence and magnitude of the overshoot or undershoot in step S23 are determined. When overshoot or undershoot does not occur or is within a predetermined range even if it occurs (that is, in step S23, the time from opening / closing operation of the door to settling is within an acceptable range) to, an operation amount X ₁ used in step S23 immediately before, is employed as the manipulated variable during the feed forward control (step S25), and terminates the test. Overshoot or undershoot occurs, and if the value exceeds the predetermined range, the operation amount X ₁ may be adjusted by the upon the (step S26) used in the previous step S23, in step S23 again step And the determination of step S24. Thus, the operation amount X ₁ to be finally adopted during the feed forward control is determined.

In the step S23～S24, as described above, after performing the test by setting the operation amount X ₁ to be slightly overshoot Pounds, final manipulated variable after adjusting in accordance with the result of the test it may be employed as the operation amount X _1, and the amount may be as a final operation amount X ₁ obtained by adding a predetermined amount α to the change amount X ₀ of the damper opening degree θ to the settling Jitsukazeryou.

Thus, in the enclosure type hood device 1 of the first embodiment, regarding the operation of the air volume accompanying the opening and closing of the door 4, the damper opening degree θ or the differential pressure ΔP or the actual air volume can be It can settle in a short time. Then, when the feed-forward control, the operation amount X ₁ exerted on the damper 7, based on the change amount X ₀ of the damper opening degree θ in the feedback control, so as not to cause excessive overshoot or undershoot, appropriately setting can do.

  At this time, feedback control and feedforward control are performed by operating the damper 7 based on the pressure in the exhaust pipe 6 and the opening degree of the door 4, so the variable air volume device is unnecessary. The air volume can be suitably controlled by the damper 7 provided with the motor 7a without installing an expensive variable air volume device, and equipment investment can be suppressed. Moreover, when the air volume operation is performed by the variable air volume device, a large differential pressure is required before and after the air volume change device, but when the air volume operation is performed by the damper 7 as in the first embodiment, the front and rear differential pressure It does not have to be so big and running costs will be reduced.

  Further, the method of performing feedback control on the opening degree of the damper 7 based on the opening degree of the door 4 is, for example, compared to the method of performing air volume control based on the differential pressure before and after the variable air quantity device provided in the exhaust pipe. There is also an advantage that the necessary calculations are easy.

  As described above, in the first embodiment, the space S surrounded by the wall 3 and the door 4, the exhaust pipe 6 through which the exhaust gas from the space S flows, and the space S through the exhaust pipe 6 A method of controlling an exhaust air flow rate of an enclosure type hood apparatus having a fan 5 for exhausting, the damper 7 capable of operating the opening degree in the middle of the exhaust pipe 6, and the measured pressure on the upstream side of the damper 7 in the exhaust pipe 6 The feedback control is performed to adjust the opening degree of the damper 7 so that the value approaches the set pressure value calculated based on the opening degree of the door 4, and when the door 4 is subjected to the opening / closing operation, On the other hand, feedforward control is performed to perform an opening operation of a predetermined operation amount. By performing the opening operation instantaneously by feedforward control in addition to feedback control, it is possible to quickly operate the opening of the damper 7 to the vicinity of the target opening and to quickly settle the air volume.

  Further, in the first embodiment, the operation amount of the opening operation performed on the damper 7 in the feedforward control is the case where the opening / closing operation of the door 4 is performed while the feedback control is performed in the enclosure type hood device 1 It can determine based on the variation | change_quantity of the opening degree of the damper 7 in these.

  Therefore, according to the first embodiment, it is possible to realize the preferable followability of the exhaust air flow rate to the opening and closing of the door simply and at low cost.

  FIG. 11 shows another example of the form of the enclosed food | hood apparatus by implementation of this invention. In the second embodiment, the configuration is provided with a plurality of (three in this case) enclosure type hood devices 101, 201 and 301, and the exhaust of each of these three enclosure type hood devices 101, 201 and 301 is taken. The pipes 106, 206, and 306 merge into one downstream and communicate with the outside. A fan 5 is installed at a position downstream of the junction of the exhaust pipes 106, 206, and 306.

  The configuration of each enclosure type hood device 101, 201, 301 is the same as that of the enclosure type hood device 1 (see FIG. 1) of the first embodiment, and the walls 103, 203 above the work benches 102, 202, 302, respectively. , 303, and spaces A, B, C surrounded by the doors 104, 204, 304. Exhaust pipes 106, 206, and 306 are connected to the upper side of the spaces A, B, and C, respectively, and the fans 5 exhaust air from the spaces A, B, and C, respectively.

  Damper 107, 207, and 307 provided with motor 107a, 207a, and 307a are arranged in the middle of exhaust pipe 106, 206, and 306, respectively, and each control device 108, 208, 308 to motor 107a, 207a, 307a, respectively. The opening degree is controlled in accordance with the input operation signals 107b, 207b and 307b.

  The opening degree of each door 104, 204, 304 is detected by an opening degree sensor 109, 209, 309, respectively, and is input to each control device 108, 208, 308 as an opening degree signal 109a, 209a, 309a. Further, pressure sensors 110, 210, and 310 are installed at positions upstream of the dampers 107, 207, and 307 in the exhaust pipes 106, 206, and 306, respectively. The detection values of the pressure sensors 110, 210, and 310 are input to the control devices 108, 208, and 308 as pressure signals 110a, 210a, and 310a, respectively.

  Here, the opening degree signals 109a, 209a, and 309a of the opening degree sensors 109, 209, and 309 are respectively input to any of the control devices 108, 208, and 308. As will be described later, it is a configuration for operating the opening degree of the damper of one enclosed type hood device based on the opening degree information of the door of the other enclosed type hood device.

  The operation signals 107b, 207b, and 307b are individually input from the control device 108 to the motor 107a, from the control device 208 to the motor 207a, and from the control device 308 to the motor 307a. In addition, it is sufficient if the pressure signals 110a, 210a, and 310a are also input from the pressure sensor 110 to the controller 108, from the pressure sensor 210 to the controller 208, and from the pressure sensor 310 to the controller 308, respectively. It is.

  In each enclosure type hood apparatus, feedback control and feedforward control similar to those of the first embodiment (see FIG. 1) are performed.

  Here, as in the second embodiment, when the exhaust pipes 106, 206, and 306 are connected to each other between the plurality of enclosed hood devices 101, 201, and 301, the pressure in the exhaust pipe in a certain enclosed hood device The exhaust air volume is affected by the opening and closing operation of the door in another enclosed hood device. For example, when the door 104 of the enclosure type hood device 101 is opened, the pressure in the exhaust pipes 206, 306 of the other enclosure type hood devices 201, 301 is interlocked with the increase of the absolute value of the pressure in the exhaust pipe 106. Under the influence, not only the air volume of the enclosure-type hood device 101 but also the air volume of the enclosure-type hood devices 201 and 301 fluctuate. The influence of the opening and closing operation of the door between the enclosed hood devices is automatically corrected if feedback control (see FIGS. 3 and 4) is performed in each of the enclosed hood devices, but the feedback is Relying on control alone takes time to settle.

  Therefore, in the second embodiment, in addition to performing feedback control and feedforward control on the damper opening degree according to the opening and closing of the door in the one enclosed hood device in the one enclosed hood device, the other The opening and closing of the door in the enclosure type hood device is also detected, and feedback control and feed forward control are performed on the damper opening degree of one enclosure type hood device.

  For example, in each enclosure type hood apparatus, the case where opening and closing operation of a damper is performed only with feedback control to opening and closing operation of the door in other enclosure type hood apparatuses is assumed. In this case, for example, when the door 204 of the enclosure type hood device 201 is opened, the differential pressure ΔP in the exhaust pipe 206 increases, while in the exhaust pipes 106 of the other enclosure type hood devices 101, the pressure difference ΔP is temporarily once It falls (see the broken line in FIG. 12). Thereafter, feedback control performed in the enclosed hood device 101 causes the differential pressure ΔP in the exhaust pipe 106 to recover over time. Although the pressure fluctuation in the exhaust pipe 106 of the enclosure type hood device 101 is described here, the same fluctuation also occurs in the pressure in the exhaust pipe 306 of the enclosure type hood device 301.

  Here, in the enclosure type hood device 101, the open / close operation of the door 204 of the enclosure type hood device 201 is detected to execute feedforward control (see FIGS. 5 and 6). The opening and closing of the door 204 in the enclosure type hood device 201 can be detected by an opening degree signal 209 a input from the opening degree sensor 209 to the control device 108. If the amount of operation of the damper 107 in feed forward control is appropriate, for example, as indicated by a solid line in FIG. 12, the fluctuation of the differential pressure ΔP in the enclosed hood device 201 when the door 204 is opened is minimized. Can be Thus, in one enclosure type hood device, the influence of the differential pressure ΔP and the actual air volume can be suppressed by opening and closing the door in the other enclosure type hood device, and the actual air volume can be quickly set.

  The operation amount of the damper 107 required in the feedforward control in the enclosed hood device 101 accompanying the opening and closing operation of the door 204 is different from the operation amount required in the feedforward control accompanying the opening and closing operation of the door 104. When the operation amount of the damper 107 is not appropriate, overshoot or undershoot occurs as shown by a one-dot chain line or a two-dot chain line in FIG. 12, and if this amount is excessive, the time for the actual air volume to deviate from the set air volume It will happen for a long time. Therefore, when determining the operation amount of the damper in the feedforward control of one enclosure type hood apparatus accompanying the opening and closing operation of the door of another enclosure type hood apparatus, it is individually determined for each combination of each enclosure type hood apparatus. It should.

The procedure of the test for determining the operation amount of the damper may be basically the same as the procedure shown in FIG. Specifically, in the case of the second embodiment, the door 204 of the enclosure type hood device 201 is opened and closed while performing feedback control with regard to the enclosure type hood device 101 (step S21). calculates a change amount _{X 0} of the opening (step S22). Next, while the feedforward control is performed by the enclosure type hood device 101 in addition to the feedback control, the opening and closing operation of the door 204 of the enclosure type hood device 201 is performed (step S23). In this case, as the operation amount _{X 1} of the damper 107, using the amount of change _{X 0} obtained in step S22. Depending on the determination in step S24, proceed to step S25, again repeated step S23 and step S24 while increasing or decreasing the manipulated variable _{X 1} proceeds to step S26, determines the operation amount _{X 1} of the final damper 107.

Then similarly, opening and closing the door 304 of the enclosure hood device 301 while executing the control of the enclosure hood apparatus 101 determines the operation amount X _1. In addition, similar tests are performed on other enclosed hood devices. While executing the control of the enclosure hood device 201 by opening and closing the door 104 of the enclosure hood apparatus 101 determines the operation amount X ₁ in the same procedure. Furthermore, opening and closing the door 304 of the enclosure hood device 301 while executing the control of the enclosure hood apparatus 201 determines the operation amount X ₁ in the same procedure. Regard enclosure hood apparatus 301, were tested for opening and closing the door 104, 204 of the enclosure hood device 101, 201, may be determined operation amount _{X 1} in the same procedure.

  As described above, in the second embodiment, the exhaust pipes 106, 206, and 306 of the plurality of enclosed hood devices 101, 201, and 301 are joined together, and in each of the enclosed hood devices 101, 201, and 301, The feedback control and the feedforward control are performed, and the opening degree operation of a predetermined operation amount is performed when the door of another enclosed hood device is subjected to opening / closing operation with respect to the damper of the enclosed hood device It is designed to execute feed forward control. In one enclosure type hood device, by detecting the opening and closing of the door in the other enclosure type hood device and performing feedforward control, the opening and closing of the door in the other enclosure type hood device is performed. The influence of the air volume can be reduced and the actual air volume can be settled quickly.

  In the exhaust air flow control method of the enclosure type hood device of the present invention, the opening degree of the damper in the feedforward control executed by the one enclosure type hood device with the opening and closing operation of the door of the other enclosure type hood device. The operation amount is the opening degree of the damper of the one enclosed hood device when the opening and closing operation of the door of the other enclosed hood device is performed while performing the feedback control in the one enclosed hood device. It can be determined based on the amount of change.

  The other configurations and effects are the same as those of the first embodiment, and thus the description thereof is omitted. However, also according to the second embodiment, a suitable follow-up property of the exhaust air volume to the opening and closing of the door is simple and low cost. It can be realized.

  The enclosed hood device and the exhaust air flow rate control method of the present invention are not limited to the above-described embodiments, and various modifications can of course be added without departing from the scope of the present invention. .

Reference Signs List 1 enclosure type hood device 3 wall 4 door 5 fan 6 exhaust pipe 7 damper 9 opening degree sensor 10 pressure sensor 101 enclosure type hood device 103 wall 104 door 106 exhaust pipe 107 damper 109 opening degree sensor 110 pressure sensor 201 enclosure type hood device 203 Wall 204 Door 206 Exhaust pipe 207 Damper 209 Opening sensor 210 Pressure sensor 301 Enclosure type hood device 303 Wall 304 Door 306 Exhaust pipe 307 Damper 309 Opening sensor 310 Pressure sensor S space A space B space C space C space

Claims (6)

A method of controlling an exhaust air flow rate of an enclosed hood device comprising: a space surrounded by a wall and a door; an exhaust pipe through which exhaust gas from the space flows; and a fan exhausting the space from the space through the exhaust pipe ,
A damper capable of operating the opening degree is provided in the middle of the exhaust pipe,
The feedback control is performed to adjust the opening degree of the damper so that the measured pressure value on the upstream side of the damper in the exhaust pipe approaches the set pressure value calculated based on the opening degree of the door.
A method of controlling an exhaust air flow rate of an enclosed hood device, comprising performing feedforward control for performing an opening operation of a predetermined operation amount on the damper when an opening / closing operation is applied to the door.   The amount of opening operation performed on the damper in the feedforward control is the amount of change in the opening of the damper when the door is opened and closed while the feedback control is performed in the enclosed hood device. The method of controlling an exhaust air flow rate of an enclosed type hood device according to claim 1, wherein the method is determined based on the following equation. Combining the exhaust pipes of the plurality of enclosed hood devices;
The feedback control and the feedforward control are performed in each of the enclosed hood devices.
A feedforward control is performed to perform an opening operation of a predetermined operation amount when the opening / closing operation is applied to the door of another enclosure type hood apparatus with respect to the damper of one enclosure type hood apparatus. The exhaust air flow control method of the enclosure type hood apparatus of claim 1 or 2.   The operation amount with respect to the opening degree of the damper in the feedforward control executed by the one enclosed hood device along with the opening and closing operation of the door of the other enclosed hood device is the feedback in the one enclosed hood device It is determined based on the amount of change in the opening degree of the damper of the one enclosed hood device when performing the opening and closing operation of the door of the other enclosed hood device while performing control. The exhaust air volume control method of the enclosure type hood apparatus of 3 statement. Space surrounded by walls and doors,
An exhaust pipe through which exhaust gas from the space flows;
A fan exhausting air from the space through the exhaust pipe;
A damper installed in the middle of the exhaust pipe so as to be operable at an opening degree;
An opening sensor that detects the opening of the door;
A pressure sensor for detecting the pressure in the exhaust pipe on the upstream side of the damper;
The feedback control is performed to adjust the opening degree of the damper so that the measured pressure value on the upstream side of the damper in the exhaust pipe approaches the set pressure value calculated based on the opening degree of the door.
An enclosure type hood device configured to execute feedforward control for performing an opening degree operation of a predetermined operation amount to the damper when the opening and closing operation is applied to the door. The exhaust pipes of a plurality of the enclosed hood devices are joined,
The feedback control and the feedforward control are performed in each of the enclosed hood devices.
The damper of one enclosure type hood device is configured to execute feedforward control to perform an opening degree operation of a predetermined operation amount when an opening and closing operation is applied to a door of another enclosure type hood device. The enclosed hood apparatus according to claim 5, characterized in that:

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