Ventilation device and control method for ventilation device

Abstract

This ventilation device (100) comprises: a ventilation device body (1); an air supply fan (2) provided inside the ventilation device body (1); a collective duct (5) connected to the air supply fan (2); first, second, and third branch ducts (6-1, 6-2, 6-3) branched from the collective duct (5) and connected to respective rooms; a pressure sensor (4) for detecting static pressure in the collective duct (5); and a control circuit unit (3) for adjusting a control gain for controlling the output of the air supply fan (2) on the basis of the difference between a target static pressure, which is a set target value of the static pressure, and a detected value of the pressure sensor (4). The air volume of the air supply fan (2) is controlled so that the detected value of the pressure sensor (4) is the target static pressure, and the control gain is adjusted by the sign of the difference.

Description

Ventilation device and ventilation device control method

[0001] The present disclosure relates to a ventilation device that ventilates a room by generating an air flow, and a method for controlling the ventilation device.

[0002] Ventilation systems are connected to ducts that connect the indoor and outdoor spaces, and ventilate the room by circulating the air in the duct. Ventilation systems sometimes use constant airflow control to keep the airflow constant, in order to address issues such as changes in airflow due to the condition of the duct.

[0003] The following Patent Document 1 discloses a technology in which a pressure sensor that detects static pressure is installed in an air supply duct, and the output of a blower is controlled based on the detection signal of the pressure sensor so that the static pressure in the air supply duct remains constant.

[0004] Patent No. 3370449

[0005] As described above, the technology of Patent Document 1 controls the output of the blower to maintain a constant static pressure in response to changes in static pressure in the air supply duct. In other words, the technology of Patent Document 1 performs the same control when the static pressure decreases and when it increases, without recognizing the difference in control behavior for both cases. Even if the static pressure change is the same, a large increase in airflow is required when the static pressure decreases, whereas a small decrease in airflow is sufficient when the static pressure increases. If, without this understanding, airflow control is performed in the same manner in response to changes in static pressure when the airflow increases and when the airflow decreases, stable airflow control may not be achieved.

[0006] The present disclosure has been made in view of the above, and aims to provide a ventilation device that can stabilize the response to changes in static pressure.

[0007] To solve the above-mentioned problems and achieve the object, the ventilation device according to the present disclosure includes a ventilation device main body, a fan, a collecting duct, branch ducts, a pressure sensor, and a control circuit. The fan is provided inside the ventilation device main body, the collecting duct is connected to the fan, and the branch ducts branch off from the collecting duct and are connected to each room. The pressure sensor detects the static pressure in the collecting duct, and the control circuit adjusts a control gain that controls the output of the fan based on the difference between a target static pressure, which is a set target value for static pressure, and the value detected by the pressure sensor. The airflow rate of the fan is controlled so that the value detected by the pressure sensor becomes the target static pressure, and the control gain is adjusted based on the sign of the difference.

[0008] The ventilation device according to the present disclosure has the advantage of being able to stabilize the response to changes in static pressure.

[0009] FIG. 3 shows the state of air supply by a ventilation device used to explain the problem of the prior art. FIG. 1 is a diagram showing an example of the configuration of a ventilation device according to embodiment 1. FIG. 2 is a diagram showing the state of air supply by a ventilation device used to explain the problem of the prior art. FIG. 3 is a diagram showing the state of air supply by a ventilation device used to explain the problem of the prior art. FIG. 1 is a characteristic curve diagram showing the control operation of the prior art used to explain the problem of the prior art. FIG. 2 is a characteristic curve diagram showing the control operation of the prior art used to explain the problem of the prior art. FIG. 1 is a block diagram; FIG. 2 is a block diagram illustrating a configuration example of a control circuit unit of a ventilation device according to a third embodiment; FIG. 3 is a block diagram illustrating a configuration example of a control circuit unit of a ventilation device according to a third embodiment; FIG. 4 is a block diagram illustrating a configuration example of a control circuit unit of a ventilation device according to a third embodiment; FIG. 5 is a block diagram illustrating a configuration example of a control circuit unit of a ventilation device according to a third embodiment;

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A ventilation device and a control method for a ventilation device according to embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0011] Embodiment 1. Figure 1 is a diagram showing an example of the configuration of a ventilation device 100 according to embodiment 1. Figure 1 shows, as main components of the ventilation device 100 according to embodiment 1, a ventilation device main body 1, an air supply fan 2, a control circuit unit 3, a pressure sensor 4, a collecting duct 5, first, second and third branch ducts 6-1, 6-2, 6-3, and first, second and third switches 7-1, 7-2, 7-3.

[0012] The supply air fan 2 is installed inside the ventilation device main body 1. The collecting duct 5 is connected to the supply air fan 2. The pressure sensor 4 is installed in the collecting duct 5 immediately after the supply air output and detects the static pressure of the collecting duct 5. First, second, and third branch ducts 6-1, 6-2, and 6-3 branch off from the collecting duct 5 and connect to each room. The first, second, and third branch ducts 6-1, 6-2, and 6-3 are provided with first, second, and third switches 7-1, 7-2, and 7-3, respectively. The first, second, and third switches 7-1, 7-2, and 7-3 individually open and close the air passages of each branch duct. The control circuit unit 3 is a control unit that controls the output of the supply air fan 2. As will be described in detail later, the control circuit unit 3 adjusts a control gain that controls the output of the supply air fan 2 based on the difference between the target static pressure, which is a set target value for static pressure, and the value detected by the pressure sensor 4.

[0013] Next, the reason for the problem of the prior art described in the section [Problem to be solved by the invention], that is, the problem of not being able to stably control the air volume when trying to control the air volume in the same control manner in response to changes in static pressure when increasing the air volume and when decreasing the air volume, will be explained with reference to Figs. 2 to 8.

[0014] Figures 2 to 4 are first to third diagrams showing the state of the air supply state of the ventilation device 100, which are provided for explaining the problems of the conventional technology. Figures 5 and 6 are first and second characteristic curve diagrams showing the control operation of the conventional technology, which are provided for explaining the problems of the conventional technology. Figures 7 and 8 are first and second time charts showing the change over time in static pressure due to the control operation of the conventional technology, which are provided for explaining the problems of the conventional technology.

[0015] 2 shows an example of the air supply state in the first state, which is the initial stage. Specifically, the first switch 7-1 is closed, and the first branch duct 6-1 is in a non-air supply state, while the second switch 7-2 and the third switch 7-3 are open, and the second and third branch ducts 6-2 and 6-3 are in an air supply state. In FIG. 2, the air volume of each of the second and third branch ducts 6-2 and 6-3 is 300 m ３ / h, the output of the air supply fan 2 is controlled to 60% so that the static pressure of the collecting duct 5 is 100 Pa. In this state, the total air supply volume of the ventilation device 100 is 600 m ３ / h, and the air volume of each of the second branch duct 7-2 and the third branch duct 7-3 is 300 m ３ It is assumed that the engine is operating stably at 1000kJ / h.

[0016] 3 shows a second state in which the first switch 7-1 is opened and the first branch duct 6-1 is switched to the air supply state from the first state in FIG. 2. At this time, the total air supply volume of the ventilation device 100 is 600 m3, the same as in FIG. 2. ３ / h, the air volume of the first branch duct 6-1 is 0 m ３ 200m from / h ３ / h, and the air volume of each of the second and third branch ducts 6-2 and 6-3 is 300 m ３ 200m from / h ３ At this time, the static pressure in the collecting duct 5 also drops from 100 Pa to 80 Pa.

[0017] Figure 4 shows a third state in which the output of the air supply fan 2 has increased from the second state in Figure 3. The control circuit unit 3 detects a drop in the static pressure of the collecting duct 5 using the pressure sensor 4, and increases the output of the air supply fan 2 to 80% so that the static pressure of the collecting duct 5 reaches the target value of 100 Pa. At this time, the air supply volume of the ventilation device 100 is 900 m ３ As a result, the static pressure of the collecting duct 5 becomes 100 Pa. The air volumes of the first to third branch ducts 6-1, 6-2, and 6-3 are each 300 m ３ / h, and the desired air volume can be obtained.

[0018] The relationship between static pressure and air volume at this time is shown in Figure 5. Figure 5 and Figure 6, which will be described later, are characteristic curves with the horizontal axis representing air volume and the vertical axis representing static pressure. In Figure 5, (1) is the operating point in the first state shown in Figure 2, (2) is the operating point in the second state shown in Figure 3, and (3) is the operating point in the third state shown in Figure 4. When transitioning from the first state shown in Figure 2 to the third state shown in Figure 4 via the second state shown in Figure 3, the operating point moves as shown in Figure 5. This movement of the operating point occurs when one branch duct is opened and the static pressure temporarily drops, as shown in Figures 2 to 4.

[0019] In contrast to this, Figure 6 additionally shows the behavior on the diagram when another branch duct is closed and the static pressure temporarily increases. In Figure 6, the behavior of the operating point indicated by (1) is when the static pressure decreases, and the behavior of the operating point indicated by (2) is when the static pressure increases.

[0020] As shown in Figure 6, even if the range of change in static pressure is the same, the change in air volume becomes larger when the static pressure decreases, and the change in air volume becomes smaller when the static pressure increases. In other words, when the static pressure decreases, the air volume needs to be increased significantly, whereas when the static pressure increases, the decrease in air volume can be small. Therefore, if air volume control is performed with the same control gain for the range of change in static pressure when increasing and decreasing the air volume, it is expected that stable control will not be possible.

[0021] Two examples showing the change over time of static pressure due to the control operation of the prior art are shown in Figures 7 and 8. Specifically, the upper part of Figure 7 shows an example of the change in the open / closed state of the first, second and third switches 7-1, 7-2 and 7-3 during the operation of Figure 6 (1), i.e., when the static pressure drops, and the lower part of Figure 7 shows an example of the change over time of the static pressure in the collecting duct 5 at that time.

[0022] The operation of FIG. 7 will be described. First, when the first switch 7-1 opens at time t1, the static pressure in the collecting duct 5 drops. At this time, the control circuit 3 controls the supply air fan 2 to increase its air volume output. However, because the control gain in the control circuit 3 is not appropriate, the increase in air volume does not keep up with the drop in static pressure. In this case, as shown in FIG. 7, it takes time to reach the target static pressure, and the time to reach the target static pressure increases. The example in FIG. 7 occurs because the control gain in the control circuit 3 is smaller than the appropriate value.

[0023] In addition, the upper part of Figure 8 shows an example of the change in the open / closed state of the first, second and third switches 7-1, 7-2, 7-3 during the operation of (2) in Figure 6, i.e., when the static pressure rises, and the lower part of Figure 8 shows an example of the change over time in the static pressure in the collecting duct 5 at that time.

[0024] The operation of FIG. 8 will be explained. First, when the third switch 7-1 closes at time t2, the static pressure in the collecting duct 5 rises. At this time, the control circuit 3 performs control to reduce the air volume output of the supply air fan 2. However, because the control gain in the control circuit 3 is inappropriate, the reduction in air volume exceeds the target static pressure, causing large oscillations and overshooting. As a result, it takes a long time to reach the target static pressure. The example in FIG. 8 occurs because the control gain in the control circuit 3 is larger than the appropriate value.

[0025] Next, the configuration and operation of the ventilation device 100 according to embodiment 1, which solves the above-mentioned problems, will be described. First, Fig. 9 is a block diagram showing an example configuration of the control circuit unit 3 provided in the ventilation device 100 according to embodiment 1. The control circuit unit 3 includes a subtractor 31, a multiplier 32, an upper / lower limiter 33, and a gain adjuster 38.

[0026] The subtractor 31 receives the target static pressure P ＊ and the actual static pressure Px are input. The actual static pressure Px is the static pressure detected by the pressure sensor 4. The subtractor 31 subtracts the target static pressure P ＊and the actual static pressure Px. Gain adjuster 38 calculates a control gain Ga based on the difference ΔP as shown in the figure. Control gain Ga is adjusted depending on the positive or negative sign of the difference ΔP. Specifically, control gain Ga is adjusted so that it is smaller when the difference ΔP is positive and larger when the difference is negative. Multiplier 32 converts the difference ΔP into an airflow target value. "K" in the figure is a conversion coefficient for converting the difference ΔP into the airflow target value. The airflow target value output from multiplier 32 is limited to a value between an upper limit value (Upper) and a lower limit value (Lower) by upper / lower limiter 33. The output of upper / lower limiter 33 is sent to supply air fan 2 as an airflow command value Qcont.

[0027] The control circuit unit 3 can be realized by an electronic circuit, which is dedicated hardware, or a controller equipped with a processor and memory. Alternatively, some of the functions of the control circuit unit 3 may be realized by dedicated hardware, and the remaining functions may be realized using a processor and memory.

[0028] Next, the effects of using the ventilation device 100 according to embodiment 1 will be described with reference to Fig. 10 and Fig. 11. Fig. 10 and Fig. 11 are first and second time charts used to explain the effects of the ventilation device 100 according to embodiment 1. The open / closed states and changes thereof of the first, second, and third switches 7-1, 7-2, and 7-3 in Fig. 10 are the same as those in Fig. 7, and the open / closed states and changes thereof of the first, second, and third switches 7-1, 7-2, and 7-3 in Fig. 11 are the same as those in Fig. 8.

[0029] As described above, the gain adjuster 38 decreases the control gain Ga when the sign of the difference ΔP is positive, and increases the control gain Ga when the sign of the difference ΔP is negative. That is, in the ventilation device 100 of the first embodiment, the control gain Ga is increased when the actual static pressure falls below the target static pressure, so that the target static pressure can be reached more quickly, as shown in Fig. 10. Furthermore, the control gain Ga is decreased when the actual static pressure rises above the target static pressure, so that the target static pressure can be stably converged to without excessive control, as shown in Fig. 11.

[0030] A specific configuration example of the gain adjuster 38 is shown in Fig. 12. Fig. 12 is a diagram showing a first configuration example of the gain adjuster 38 provided in the control circuit unit 3 of embodiment 1. As shown in Fig. 12, the gain adjuster 38 can be realized using an adder 381 and a switch 382.

[0031] The gain adjuster 38 shown in Fig. 12 is configured to include an adder 381 and a switch 382. The switch 382 receives a target static pressure P ＊ and the actual static pressure Px, a correction gain "+A" which is a positive value, and a correction gain "-B" which is a negative value are input to the switch 382. The switch 382 outputs the correction gain "+A" when the difference ΔP is positive, and outputs the correction gain "-B" when the difference ΔP is negative. The adder 381 receives the reference gain Gs and the correction gain output from the switch 382. The adder 381 performs correction by adding the correction gain to the reference gain Gs, and outputs the added value as the control gain Ga.

[0032] Note that the reference gain Gs may be set in accordance with the case where the difference ΔP is negative, the correction gain "+A" may be set to a value larger than that in the configuration of Fig. 12, and the correction gain "-B" may be set to 0. Conversely, the reference gain Gs may be set in accordance with the case where the difference ΔP is positive, the correction gain "+A" may be set to 0, and the correction gain "-B" may be set to a value smaller than that in the configuration of Fig. 12.

[0033] As described above, the first configuration example shown in FIG. 12 is a method of outputting the adjusted control gain Ga by adding the positive or negative correction gain output from the switch 382 by the adder 381.

[0034] 13 shows another specific configuration example of the gain adjuster 38. Fig. 13 is a diagram showing a second configuration example of the gain adjuster 38 provided in the control circuit unit 3 according to the first embodiment. The gain adjuster 38 shown in Fig. 13 is configured to include a multiplier 383 and a switch 384.

[0035] The switch 384 is connected to the target static pressure P ＊and the actual static pressure Px, a correction gain "C" that is a value greater than 1, and a correction gain "D" that is a value greater than 0 and less than 1 are input to the switch 384. The switch 384 outputs the correction gain "C" when the difference ΔP is positive, and outputs the correction gain "D" when the difference ΔP is negative. The multiplier 383 receives the reference gain Gs and the correction gain output from the switch 384. The multiplier 383 corrects the reference gain Gs by multiplying it by the correction gain, and outputs the multiplied value as the control gain Ga.

[0036] It is also possible to set the reference gain Gs in accordance with the case where the difference ΔP is negative, set the correction gain "C" to a value larger than that in the configuration of Fig. 13, and set the correction gain "D" to 1. Conversely, it is also possible to set the reference gain Gs in accordance with the case where the difference ΔP is positive, set the correction gain "C" to 1, and set the correction gain "D" to a value smaller than that in the configuration of Fig. 13.

[0037] As described above, the second configuration example shown in FIG. 13 is a method of outputting the adjusted control gain Ga by multiplying the correction gain output from the switch 384 by the multiplier 383 .

[0038] With the above configuration, the ventilation device 100 according to embodiment 1 can stably control the air volume to match the target static pressure, regardless of whether the static pressure detected by the pressure sensor 4 increases or decreases.

[0039] In the first embodiment, the control gain is increased when the static pressure decreases and decreased when the static pressure increases. However, the present invention is not limited to this control mode. Some supply air fans have characteristics that cause the control gain to operate in the opposite direction. Therefore, depending on the characteristics of the supply air fan, the control gain may be reversed, that is, gain adjuster 38 may decrease control gain Ga when the sign of difference ΔP is positive and increase control gain Ga when the sign of difference ΔP is negative.

[0040] Furthermore, in the first embodiment, the case where the fan is the supply fan 2 has been described, but the above-described control method can also be applied to an exhaust fan. That is, the control method according to the first embodiment can also be suitably used in a ventilation device equipped with an exhaust fan. For example, in a ventilation device having a supply fan and an exhaust fan such as a total heat exchanger, the control method according to the first embodiment can be suitably used to control the air volume in at least one of the supply air duct and the exhaust air duct.

[0041] Furthermore, the ventilation device 100 according to the first embodiment may be configured so that the control operation of the supply air fan and the exhaust air fan can be freely switched between enabled and disabled using a setting device (not shown). With the ventilation device 100 configured in this manner, it becomes possible to select whether or not to apply the control method of the first embodiment depending on, for example, the installation environment, the operating time, etc. As a result, when the capacity of the control circuit unit 3 is limited, the control method of the first embodiment can be applied only when air volume control is truly necessary.

[0042] As described above, the ventilation device according to the first embodiment includes a control circuit that adjusts a control gain for controlling the output of a fan provided inside the ventilation device body based on the difference between a target static pressure, which is a set target value for static pressure, and a value detected by a pressure sensor that detects the static pressure in the collecting duct. The airflow rate of the fan is controlled so that the value detected by the pressure sensor becomes the target static pressure, and the control gain is adjusted based on the sign of the difference between the target static pressure and the value detected by the pressure sensor. With a ventilation device configured in this manner, airflow rate control is performed using a control gain appropriate for each case, whether the static pressure in the supply air duct or the exhaust air duct decreases or increases. This makes it possible to stabilize the response to changes in the static pressure in the supply air duct or the exhaust air duct.

[0043] Furthermore, the control method for a ventilation device according to the first embodiment is applied to a ventilation device including a fan provided inside the ventilation device main body, a collecting duct connected to the fan, a pressure sensor for detecting the static pressure in the collecting duct, and branch ducts branching off from the collecting duct and connected to each room. In the control method for a ventilation device according to the first embodiment, when controlling the output of the fan based on the difference between a target static pressure, which is a set target value for static pressure, and the value detected by the pressure sensor, the control method adjusts the airflow rate of the fan so that the value detected by the pressure sensor matches the target static pressure while adjusting a control gain for controlling the output of the fan based on the sign of the difference. According to the control method for a ventilation device according to the first embodiment, airflow rate control is performed using a control gain appropriate for each case, whether the static pressure in the supply air duct or the exhaust air duct decreases or increases. This makes it possible to stabilize the response to changes in the static pressure in the supply air duct or the exhaust air duct.

[0044] Embodiment 2. Figure 14 is a diagram showing an example of the configuration of a ventilation device 100A according to embodiment 2. Compared to the configuration shown in Figure 1, in Figure 14, the control circuit unit 3 is replaced with a control circuit unit 3A. The control circuit unit 3A is configured to receive fan rotation speed Rd, which is rotation speed information of the air supply fan 2, from the air supply fan 2. The air supply state by the air supply fan 2 shows the air supply state at the initial stage, the same as in Figure 2. Note that other configurations are the same or equivalent to those in Figure 1, and the same or equivalent components are designated by the same reference numerals, and redundant explanations will be omitted.

[0045] Fig. 15 is a first characteristic curve diagram used to explain the control operation of the control circuit unit 3A provided in the ventilation device 100A according to the second embodiment. Fig. 15 shows the movement of the operating point with respect to changes in static pressure in two cases where the static pressure in the steady state is different. In case (1) and case (2), the amount of decrease in static pressure is the same, but the amount of increase in air volume to return to the target static pressure is different. In the second embodiment, in order to reflect this difference in the control, the target static pressure P ＊ and the actual static pressure Px, and also the fan rotation speed Rd, which is rotation speed information of the intake air fan 2, is used to change the magnitude of the control gain Ga.

[0046] Fig. 16 is a block diagram showing an example configuration of a gain adjuster 38A provided in the control circuit unit 3A of embodiment 2. Although the configuration of the control circuit unit 3A is not shown, the control circuit unit 3A is configured by replacing the gain adjuster 38 in Fig. 9 with the gain adjuster 38A shown in Fig. 16. The gain adjuster 38A is configured to include a multiplier 383, a switch 384, and first and second tables 385 and 386. The functions of the multiplier 383 and the switch 384 are the same as or equivalent to those of the gain adjuster 38 shown in Fig. 13.

[0047] Next, the operation of the ventilation device 100A according to the second embodiment will be described. First, the control circuit unit 3A acquires the fan rotation speed Rd during initial setup. Because the fan rotation speed Rd is proportional to the airflow rate of the supply air fan 2, the control circuit unit 3A can grasp the approximate airflow rate. The fan rotation speed Rd is input to a first table 385. The first table 385 stores table values ​​(C0, C1, C2, ...), and the first table 385 outputs a table value corresponding to the magnitude of the fan rotation speed Rd to the switch 384 as a correction gain. Similarly, the fan rotation speed Rd is input to a second table 386. The second table 386 stores table values ​​(D0, D1, D2, ...), and the second table 386 outputs a table value corresponding to the magnitude of the fan rotation speed Rd to the switch 384 as a correction gain.

[0048] The operation of the switch 384 is the same as that in embodiment 1. When the difference ΔP is positive, the switch 384 outputs the table value input from the first table 385 to the multiplier 383, and when the difference ΔP is negative, the switch 384 outputs the table value input from the second table 386 to the multiplier 383. The subsequent operation is as described above.

[0049] As described above, in the ventilation device 100A according to the second embodiment, the fan rotation speed Rd of the supply air fan 2 is acquired during initial setup, and the value of the control gain Ga is corrected based on the fan rotation speed Rd and the detection value of the pressure sensor 4 at a timing different from the timing at which the fan rotation speed Rd is acquired.

[0050] With the above configuration, the ventilation device 100A according to the second embodiment has the advantage of being able to adjust the air volume in response to changes in static pressure more stably than the ventilation device 100 according to the first embodiment.

[0051] The gain adjuster 38A shown in FIG. 16 is configured by applying the first and second tables 385, 386 to the gain adjuster 38 shown in FIG. 13, but it may also be configured by applying the first and second tables 385, 386 to the gain adjuster 38 shown in FIG. 12.

[0052] Also, as described above, the fan rotation speed Rd is acquired during initial setup. An example of the initial setup is "when the device is started up." Here, "when the device is started up" refers to when the rotation speed of the air supply fan 2 in the ventilation device 100A stabilizes after the ventilation device 100A is started up. The control circuit unit 3A acquires the fan rotation speed Rd during device startup. Note that a time when the operation settings are changed by an operator or the like while the ventilation device 100A is in operation may also be considered as "when the initial setup is started up."

[0053] The fan rotation speed Rd can also be acquired periodically or irregularly. FIG. 17 is a second characteristic curve diagram used to explain the control operation of the control circuit unit 3A included in the ventilation device 100A according to the second embodiment. FIG. 17 shows the movement of the operating point relative to changes in static pressure in two cases on the same pressure loss characteristic curve. In the example of FIG. 17 , the change in air volume is greater in case (2) where the static pressure is low than in case (1) where the static pressure is high. As described above, the fan rotation speed Rd is proportional to the air volume of the supply air fan 2. Furthermore, as shown in FIG. 17 , if the static pressure at the operating point is different, the change in air volume will differ even on the same pressure loss characteristic curve. For this reason, a more desirable embodiment involves appropriately acquiring the fan rotation speed Rd, setting the reference gain Gs using the acquired fan rotation speed Rd, and correcting the control gain Ga using the set reference gain Gs.

[0054] As described above, in the ventilation device according to the second embodiment, fan rotation speed information is acquired during initial setup, and the control gain value is corrected at a timing different from the initial setup based on the rotation speed information and the detection value of the pressure sensor. The initial setup may be performed when the device is started up, or when the device's operation settings are changed. According to the ventilation device according to the second embodiment, the control gain value is corrected based on the rotation speed information, thereby enabling more stable air volume control compared to the ventilation device according to the first embodiment. Note that the reference gain may be changed during initial setup, and the control gain may be corrected relative to the reference gain.

[0055] Furthermore, in the ventilation device according to the second embodiment, rotation speed information may be acquired as needed, the reference gain may be changed when the rotation speed information is acquired, and the control gain may be corrected relative to the reference gain. In the ventilation device, the amount of control of the airflow changes depending on the rotation speed. Therefore, if rotation speed information is acquired as needed and the control gain is updated each time the information is acquired, more stable control can be achieved.

[0056] Third Embodiment. Figure 18 is a block diagram showing an example of the configuration of a control circuit unit 3B according to a third embodiment. Compared to the configuration shown in Figure 9, in Figure 18, the gain adjuster 38 is omitted, and instead, a timing control unit 34 is added after the upper / lower limiter 33. The timing control unit 34 includes a timer 342 that measures time and a switch 341 that updates the airflow command value Qcont that commands the output of the supply air fan 2. A reference gain Gs is input to the multiplier 32. The reference gain Gs is set to a high control gain that is suitable for increasing the airflow command value Qcont when the static pressure decreases. The other configuration is the same or equivalent to that shown in Figure 9, and the same or equivalent components are designated by the same reference numerals, and redundant description will be omitted.

[0057] Next, the operation of the control circuit unit 3B will be described. The switch 341 is periodically turned on by the timer 342. When the switch 341 is turned on, the current air volume command value Qcont is updated to a new air volume command value Qcont. Here, the difference ΔP, which is the output of the subtractor 31, is input to the timer 342. When the sign of the difference ΔP is positive, that is, when the actual static pressure Px is smaller than the target static pressure P ＊ If the temperature is lower than the normal temperature, timer 342 measures a time shorter than normal, and when the measured time is reached, switch 341 is turned on to issue a command to supply air fan 2 as air volume command value Qcont, based on the value output from upper / lower limiter 33. Here, "a time shorter than normal" refers to a time shorter than the time it takes for supply air fan 2 to reach the air volume corresponding to air volume command value Qcont after receiving the command.

[0058] With the above-described configuration, in the control circuit unit 3B of the third embodiment, the switch 341 is controlled to be turned on and off based on a signal from the timer 342, and the timing of the signal output from the timer 342 to the switch 341 is controlled based on the target static pressure P ＊ Specifically, the actual static pressure Px is controlled by the sign of the difference ΔP between the target static pressure P ＊ , the airflow command value Qcont is updated frequently. This allows the static pressure Px to be adjusted to the target static pressure Px even when the reference gain Gs is set to a high value and the change in airflow rate is small relative to the change in actual static pressure Px. ＊ This can prevent overshooting, and an operation equivalent to that achieved by reducing the reference gain Gs can be achieved.

[0059] As described above, the ventilation device according to the third embodiment includes a control circuit that controls the timing of issuing a command to the fan output while controlling the fan output based on the difference between a target static pressure, which is a set target value for static pressure, and the value detected by a pressure sensor that detects the static pressure in the collecting duct. The fan airflow is controlled so that the value detected by the pressure sensor becomes the target static pressure, and the timing of issuing a command to the fan output is controlled by the sign of the difference. With a ventilation device configured in this manner, controlling the timing of issuing a command to the fan output can achieve an operation equivalent to reducing the control gain, thereby enabling a stabilized response to changes in the static pressure in the supply air duct or the exhaust air duct, similar to the ventilation device according to the first embodiment.

[0060] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0061] 1 Ventilation device main body, 2 Air supply fan, 3, 3A, 3B Control circuit unit, 4 Pressure sensor, 5 Collecting duct, 6-1 First branch duct, 6-2 Second branch duct, 6-3 Third branch duct, 7-1 First switch, 7-2 Second switch, 7-3 Third switch, 31 Subtractor, 32, 383 Multiplier, 33 Upper and lower limiter, 34 Timing control unit, 38, 38A Gain adjuster, 100, 100A Ventilation device, 341 Switch, 342 Timer, 381 Adder, 382, ​​384 Switch, 385 First table, 386 Second table.

Claims

1. A ventilation device comprising: a ventilation device main body; a fan provided inside the ventilation device main body; a collecting duct connected to the fan; branch ducts branching from the collecting duct and connected to each room; a pressure sensor that detects the static pressure of the collecting duct; and a control circuit unit that adjusts a control gain that controls the output of the fan based on the difference between a target static pressure that is a set target value for static pressure and the detection value of the pressure sensor, wherein the airflow rate of the fan is controlled so that the detection value of the pressure sensor becomes the target static pressure, and the control gain is adjusted based on the sign of the difference.

2. The ventilation device according to claim 1, wherein the control gain is smaller when the difference is positive and larger when the difference is negative.

3. The ventilation device according to claim 1, wherein the control gain is increased when the difference is positive and is decreased when the difference is negative.

4. A ventilation device as described in any one of claims 1 to 3, characterized in that information on the rotation speed of the fan is acquired during initial setup, and the value of the control gain is corrected at a timing different from that during the initial setup based on the rotation speed information and the detection value of the pressure sensor.

5. The ventilation device according to claim 4, wherein the initial setting is performed when the device is started up.

6. The ventilation device according to claim 4, wherein the initial setting is when the operation settings of the device are changed.

7. The ventilation device according to claim 4, wherein the reference gain is changed during the initial setting, and the value of the control gain is corrected with respect to the reference gain.

8. The ventilation device according to claim 4, characterized in that the rotation speed information is acquired as appropriate, the reference gain is changed when the rotation speed information is acquired, and the value of the control gain is corrected with respect to the reference gain.

9. A ventilation device comprising: a ventilation device main body; a fan provided inside the ventilation device main body; a collecting duct connected to the fan; a pressure sensor that detects the static pressure of the collecting duct; branch ducts that branch off from the collecting duct and are connected to each room; and a control circuit unit that controls the output of the fan based on the difference between a target static pressure that is a set target value for static pressure and the detection value of the pressure sensor, and controls the timing for issuing a command to output the fan, wherein the airflow rate of the fan is controlled so that the detection value of the pressure sensor becomes the target static pressure, and the timing for issuing a command to output the fan is controlled by the sign of the difference.

10. The ventilation device described in claim 9, characterized in that the control circuit unit comprises a timer that measures time and a switch that switches whether or not to output a command value that commands the output of the fan, the switch being controlled to turn on and off based on a signal from the timer, and the timing of the signal output from the timer to the switch being controlled by the sign of the difference.

11. The ventilation device according to claim 1 or 9, characterized in that the air volume is controlled in at least one of the intake air duct and the exhaust air duct.

12. The ventilation device according to claim 1 or 9, characterized in that it is configured so that the air volume control can be selected to be performed in at least one of the intake air duct and the exhaust air duct.

13. A control method for a ventilation device that is applied to a ventilation device having a fan provided inside the ventilation device main body, a collecting duct connected to the fan, a pressure sensor that detects the static pressure of the collecting duct, and branch ducts that branch off from the collecting duct and are connected to each room, and that controls the output of the fan based on the difference between a target static pressure, which is a set target value for static pressure, and the detected value of the pressure sensor, characterized in that when controlling the output of the fan, the control gain that controls the output of the fan based on the sign of the difference is adjusted, and the air volume of the fan is controlled so that the detected value of the pressure sensor becomes the target static pressure.

14. A method for controlling a ventilation device according to claim 13, characterized in that the control gain is reduced when the detected value of the pressure sensor is greater than the target static pressure, and the control gain is increased when the detected value of the pressure sensor is less than the target static pressure.

15. A method for controlling a ventilation device according to claim 13, characterized in that the control gain is increased when the detected value of the pressure sensor is greater than the target static pressure, and the control gain is decreased when the detected value of the pressure sensor is less than the target static pressure.

16. A control method for a ventilation device that is applied to a ventilation device having a fan provided inside the ventilation device main body, a collecting duct connected to the fan, a pressure sensor that detects the static pressure of the collecting duct, and branch ducts that branch off from the collecting duct and are connected to each room, and that controls the output of the fan based on the difference between a target static pressure, which is a set target value for static pressure, and the detected value of the pressure sensor, characterized in that when controlling the output of the fan, the timing of issuing a command to output the fan is controlled based on the sign of the difference, and the air volume of the fan is controlled so that the detected value of the pressure sensor becomes the target static pressure.

17. A method for controlling a ventilation device according to any one of claims 13 to 16, characterized in that the air volume control is carried out in at least one of the intake air duct and the exhaust air duct.

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