ventilation system

Abstract

To suppress a deviation from a target wind volume of a wind volume blown out by a blower caused by a variation in characteristic of a motor when performing wind volume constant control in a blowing system.SOLUTION: A blowing system comprises: a box body 1 having a suction port 2 and a blowout port 3; a duct 67 extending from the blowout port 3; a blower 12 for blowing air sucked from the suction port 2 to the duct 67 via the blowout port 3; a voltage control part 42 for controlling a voltage applied to a motor 58 of the blower 12; and a rotation number detection part 54 for detecting a rotation number of the motor 58. The voltage control part 42 controls the voltage applied to the motor 58 so that a wind volume blown out by the blower 12 approaches a preset target wind volume. When the rotation number of the motor 58 detected by the rotation number detection part 54 is lower than a preset rotation number lower limit value, the voltage control part controls the voltage applied to the motor 58 so that the rotation number of the motor 58 reaches the rotation number lower limit value.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a ventilation system that delivers air to a space. [Background technology]

[0002] A spatial sterilization and deodorization device sprays fine water particles of a chemical agent, such as hypochlorous acid water, to sterilize a target area. For example, the liquid atomization chamber of the spatial sterilization and deodorization device releases water droplets from a hypochlorous acid solution stored in a water storage unit. The water droplets are blown by a blower unit through an air duct and released from an outlet into the target area (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] WO 20 / 158850 Summary of the Invention [Problem to be solved by the invention]

[0004] In an air blowing system, it is conceivable to perform constant air volume control, which controls the voltage applied to the motor of the air blower so that the volume of air blown by the air blower approaches a predetermined target air volume. In this case, the air volume blown by the fan may be larger or smaller than the target air volume due to variations in the characteristics of the fan motor. That is, the air volume blown by the fan may deviate from the target air volume due to variations in the motor characteristics.

[0005] The present disclosure has been made in consideration of these circumstances, and its purpose is to provide a technology that suppresses deviation of the air volume blown by a blower from the target air volume due to variations in motor characteristics when performing constant air volume control. [Means for solving the problem]

[0006] In order to solve the above problems, the air blowing system according to one aspect of the present disclosure includes a housing having an air inlet and an air outlet, a duct extending from the air outlet, and a duct for blowing air drawn in through the air inlet. Squirting Through the exit Da a blower that blows air to the object, and a voltage control unit that controls a voltage applied to a motor of the blower; Mo a rotation speed detection unit that detects the rotation speed of the motor; a current detection unit that detects a current value of the motor; Equipped with do.

[0007] The voltage control unit controls the voltage applied to the motor so that the air volume blown by the blower approaches a predetermined target air volume; when the motor rotation speed detected by the rotation speed detection unit is lower than a predetermined lower limit value, the voltage applied to the motor so that the motor rotation speed becomes the lower limit value; and when the motor current value detected by the current detection unit reaches a predetermined upper current value, the voltage applied to the motor so that the motor current value remains at the upper current value. The upper current limit is equal to or greater than the motor current value when the air volume blown by the blower reaches the lower limit air volume value defined by the specifications when the motor rotation speed is at the upper rotation speed limit.

[0008] Any combination of the above components and conversion of the expressions of the present disclosure into methods, devices, systems, etc. are also valid aspects of the present disclosure. [Effects of the Invention]

[0009] According to the present disclosure, when constant air volume control is performed, it is possible to suppress deviation of the air volume blown by the blower from the target air volume due to variations in motor characteristics. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram showing the configuration of a humidification system according to a first embodiment. [Figure 2] FIG. 2 is a diagram showing the configuration of the humidifier of FIG. [Figure 3] 2 is a diagram showing a configuration related to control of a blower of the humidifier of FIG. 1. FIG. [Figure 4]1. FIG. 4 is a diagram showing an example of the relationship between static pressure and air volume at each of a plurality of rotation speeds of the motor in the humidifier of FIG. 1, and the relationship between static pressure and air volume at each of a plurality of air path resistances of the duct. [Figure 5] 1. FIG. 4 is a diagram for explaining control when the air path resistance is the fifth resistance value and the first resistance value when the target rotation speed is set to the fifth rotation speed in the humidifier of FIG. [Figure 6] 4 is a flowchart showing the process of the voltage control unit in FIG. 3. [Figure 7] FIG. 10 is a diagram showing an example of the range of static pressure and air volume in which constant air volume control is performed between the upper limit and lower limit of the motor characteristic variation in the humidification system of the second embodiment. [Figure 8] FIG. 11 is a diagram showing an example of the range of static pressure and air volume in which constant air volume control is performed between the upper limit and lower limit of the motor characteristic variation in the humidification system of the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Example 1 Before specifically describing Example 1 of the present disclosure, an overview of Example 1 will be described. This example relates to a humidification system that humidifies an indoor space as an example of an air supply system. As an example of a humidification system, a space purification system that adjusts humidity and sprays water containing a component that purifies the air (hereinafter referred to as "air purification component") into a room will be described. The space purification system includes a space purification device that adjusts humidity and sprays water containing the air purification component. A blower in the space purification device sends air humidified by the sprayed water into the room. The air purification component may be, for example, hypochlorous acid, which has bactericidal or deodorizing properties. This sterilizes or deodorizes the room.

[0012] As mentioned above, when a target rotation speed is set according to the design value of the air path resistance and the rotation speed of the fan motor is controlled to achieve that target rotation speed, if the target rotation speed is set higher than the target rotation speed that matches the actual air path resistance, the air volume may exceed the upper limit of the specifications. If the air volume is too high, it may become over-humidified or the amount of hypochlorous acid released into the air may be too high.

[0013] Therefore, in this embodiment, when the rotation speed of the motor is lower than the target rotation speed, the voltage applied to the motor is controlled so that the air volume approaches the target air volume, and when the rotation speed of the motor is equal to or higher than the target rotation speed, the voltage applied is controlled so that the rotation speed approaches the target rotation speed. This makes it possible to prevent the air volume from becoming too large when a target rotation speed higher than the target rotation speed that matches the air path resistance is set.

[0014] The examples described below each illustrate a preferred specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, component placement and connection configurations, steps (processes), and step order shown in the following examples are merely examples and are not intended to limit the present disclosure. Therefore, among the components in the following examples, components that are not described in the independent claims that represent the highest concept of the present disclosure are described as optional components. Furthermore, in each drawing, substantially identical components are designated by the same reference numerals, and redundant descriptions are omitted or simplified.

[0015] FIG. 1 shows the configuration of a humidification system 100 according to a first embodiment. The humidification system 100 is a device that adds an air purifying component to the air (RA) from an indoor space 62 along with atomized water when circulating the air in the indoor space 62. As described above, the humidification system 100 can also be called a space purification system. The humidification system 100 sterilizes and deodorizes the indoor space 62 by supplying air (SA) that has circulated through the interior thereof to the indoor space 62. Here, hypochlorous acid is used as the air purifying component, and the water containing the air purifying component is hypochlorous acid water.

[0016] 1, the humidification system 100 includes a humidifier 10, an operating device 70, a duct 64a, a duct 64c, a low-reactivity duct 67a, and a low-reactivity duct 67c. The humidifier 10 can also be called a space purification device. In this embodiment, the low-reactivity duct 67a and the low-reactivity duct 67c are collectively called a duct 67.

[0017] Fig. 2 shows the configuration of the humidifier 10 of Fig. 1. As shown in Fig. 2, the humidifier 10 includes a housing 1, a purification air duct 5, a humidifier 14, a hypochlorous acid water generator 19, a HEPA (High Efficiency Particulate Air) filter 11, a blower 12, a temperature and humidity sensor 40, and a controller 41.

[0018] As shown in Fig. 2, the housing 1 forms the outer shell of the humidifier 10. The housing 1 has an inlet 2a, an inlet 2c, an outlet 3a, and an outlet 3c. In this embodiment, the inlet 2a and the inlet 2c are collectively referred to as the inlet 2, and the outlet 3a and the outlet 3c are collectively referred to as the outlet 3.

[0019] 2, the air inlet 2a and the air inlet 2c are arranged on one side surface of the housing 1. The air outlet 3a and the air outlet 3c are arranged on the other side surface of the housing 1 (the side surface opposite to the one side surface of the housing 1).

[0020] The air inlets 2a and 2c are intakes that respectively take in air 8a and air 8c outside the housing 1 obtained from the indoor space 62 into the humidifier 10. The air 8a and air 8c obtained from the indoor space 62 can also be called non-temperature-controlled air of the indoor space 62 that has not been temperature-controlled, or temperature-controlled air that has been temperature-controlled by an air conditioner or the like separately installed in the indoor space 62.

[0021] As shown in Fig. 1, air inlet 2a is in communication with indoor air inlet 65a provided on the ceiling or the like of indoor space 62 via duct 64a. Air inlet 2c is in communication with indoor air inlet 65c provided on the ceiling or the like of indoor space 62 via duct 64c. This allows air inlet 2a to draw air 8a from indoor space 62 into humidifier 10 through indoor air inlet 65a. Air inlet 2c is in communication with indoor air inlet 65c from indoor space 62 into humidifier 10.

[0022] Indoor air inlet 65c does not have to be provided. In this case, one end of duct 64a may be connected to indoor air inlet 65a, and the other end of duct 64a may be branched and connected to air inlet 2a and air inlet 2c.

[0023] The air outlet 3a is an outlet that discharges air 9a (SA) that has circulated inside the humidifier 10 into the indoor space 62. The air 9a contains atomized hypochlorous acid water. The air outlet 3c is an outlet that discharges air 9c (SA) that has circulated inside the humidifier 10 into the indoor space 62. The air 9c also contains atomized hypochlorous acid water.

[0024] 1, the air outlet 3a is in communication with an indoor air outlet 68a provided on the ceiling or the like of the indoor space 62 via a low-reactivity duct 67a. The air outlet 3c is in communication with an indoor air outlet 68c provided on the ceiling or the like of the indoor space 62 via a low-reactivity duct 67c. This allows the air outlet 3a to blow out air 9a that has circulated through the humidifier 10 from the indoor air outlet 68a toward the indoor space 62. The air outlet 3c is in communication with an indoor air outlet 68c toward the indoor space 62 via the indoor air outlet 68c.

[0025] Note that the air outlet 3a and the air outlet 3c are not distinguished from each other, and for example, the air outlet 3c may not be provided. In this case, one end of the low-reactivity duct 67a may be connected to the air outlet 3a, and the other end of the low-reactivity duct 67a may be branched and connected to the indoor air outlet 68a and the indoor air outlet 68c.

[0026] The low-reactivity duct 67a and the low-reactivity duct 67c are both ducts connected downstream of the purification air duct 5, and have inner walls made of a low-reactivity material that is poorly reactive with hypochlorous acid water. The low-reactivity material is, for example, a polyolefin-based material. The polyolefin-based material includes, for example, at least one of polyethylene and polypropylene.

[0027] As shown in FIG. 2, the cleaning airflow duct 5 is provided in the housing 1, and connects the intake 2 (the intake 2a and the intake 2c) with the outlet 3 (the outlet 3a and the outlet 3c).

[0028] The purification air duct 5 is an air duct through which both air 8a and air 8c flow. The purification air duct 5 can also be considered an air duct through which a mixture of air 8a and air 8c flows. The purification air duct 5 includes a HEPA filter 11, a hypochlorous acid water generator 19, a blower 12, and a humidifier 14, arranged in this order from upstream to downstream. More specifically, the hypochlorous acid water generator 19 is disposed upstream of the blower 12, adjacent to an intake port (not shown) of the blower 12. The humidifier 14 is disposed downstream of the blower 12, adjacent to an exhaust port (not shown) of the blower 12. A temperature and humidity sensor 40 is disposed between the HEPA filter 11 and the blower 12 in the purification air duct 5. The temperature and humidity sensor 40 measures the temperature and humidity of the air that has flowed through the HEPA filter 11 and outputs the measured values ​​to a control unit 41.

[0029] HEPA filter 11 is an air filter that removes dirt, dust, etc. from the air that flows into humidifier 10 and outputs purified air. HEPA filter 11 is disposed adjacent to intake port 2a and intake port 2c.

[0030] The blower 12 is a device for transporting air that has passed through the HEPA filter 11 along the purification air duct 5 to the humidifier 14. The blower 12 generates an air flow in the purification air duct 5. The blower 12 draws air through the intake port 2 and blows it into the duct 67 via the humidifier 14 and the outlet port 3 in that order. More specifically, the blower 12 is configured as a double-intake centrifugal fan. The centrifugal fan may have a known configuration and is driven by a motor (not shown). The blower 12 draws air through intake ports (not shown) provided on the left and right sides of the humidifier 14, and transports the air to the humidifier 14 through an outlet port (not shown).

[0031] In blower 12, the air volume, that is, the rotation speed, is controlled in accordance with an output signal from control unit 41. When blower 12 is operated, air is sent to humidifying unit .

[0032] The humidifying unit 14 is a unit for humidifying the air taken into the purification air duct 5, and during humidification, it adds hypochlorous acid to the air introduced from the blower 12 along with atomized water. The humidifying unit 14 can also be called an atomization unit. The humidifying unit 14 atomizes the hypochlorous acid water generated by the hypochlorous acid water generation unit 19 by centrifugal crushing and releases the atomized hypochlorous acid water into the air. The atomized hypochlorous acid water is released from the outlet 3 to the outside of the housing 1 with the liquid components evaporated.

[0033] The humidifying section 14 has a centrifugal crushing unit and a mixing tank (not shown). The humidifying section 14 rotates the centrifugal crushing unit using a humidifying motor (not shown), sucks up hypochlorous acid water stored in the mixing tank by centrifugal force, scatters, collides, and crushes it around (in the centrifugal direction), and moistens the air passing through.

[0034] The humidifier 14 adjusts the humidification capacity (amount of humidification) by changing the rotation speed of the humidifier motor in response to an output signal from the controller 41. The amount of humidification can also be considered as the amount of air purifying components added to the air. The controller 41 controls the rotation speed of the centrifugal crushing unit based on the humidity measurement value detected by the temperature and humidity sensor 72.

[0035] The hypochlorous acid water generator 19 (electrolytic cell 20 and brine tank 23) is disposed upstream of the blower 12 in the purified air duct 5. The hypochlorous acid water generator 19 dilutes brine (aqueous sodium chloride solution) stored in the brine tank 23 to a predetermined concentration in the electrolytic cell 20 and performs electrolysis to generate hypochlorous acid water of a predetermined concentration.

[0036] That is, the electrolytic cell 20 generates hypochlorous acid water by electrolyzing a chloride aqueous solution (e.g., salt water) as an electrolyte between a pair of electrodes. A general device is used for the electrolytic cell 20, and a detailed description thereof will be omitted. The electrolyte is not particularly limited as long as it is capable of generating hypochlorous acid water and contains even a small amount of chloride ions, and examples thereof include aqueous solutions in which sodium chloride, calcium chloride, magnesium chloride, etc. are dissolved as solutes. Hydrochloric acid is also acceptable. In this embodiment, an aqueous chloride solution (salt water) in which sodium chloride is added to water is used as the electrolyte.

[0037] 1, an operating device 70 (including a temperature and humidity sensor 72) is installed on a wall surface of the indoor space 62. The operating device 70 is connected to the control unit 41 by wire or wirelessly, and transmits at least the humidity setting value, the humidity measurement value, and operation mode information to the control unit 41. The operation modes include modes that specify the amount of hypochlorous acid in the air, such as a deodorizing mode, a sterilizing mode, and a normal mode.

[0038] Fig. 3 shows the configuration related to the control of blower 12 of humidifier 10 of Fig. 1. Humidifier 10 further has a rotation speed setting switch 50, a current detection unit 52, a rotation speed detection unit 54, a drive unit 56, and a motor 58. Control unit 41 has a voltage control unit 42 and a memory unit 44.

[0039] The motor 58 is provided in the blower 12 and drives the centrifugal fan. The motor 58 is, for example, a DC motor.

[0040] Voltage control unit 42 controls the voltage applied to motor 58 by outputting an instruction value to drive unit 56. Drive unit 56 applies a voltage corresponding to the instruction value of voltage control unit 42 to motor 58 to drive motor 58. Specifically, drive unit 56 generates a pulse width modulated signal having a duty ratio corresponding to the instruction value of voltage control unit 42, smooths the signal, and applies the smoothed voltage to motor 58.

[0041] The current detection unit 52 detects the current value of the motor 58 and supplies the detected current value to the control unit 41. The rotation speed detection unit 54 detects the rotation speed of the motor 58 and supplies the detected rotation speed to the control unit 41.

[0042] The rotation speed setting switch 50 is provided, for example, on a circuit board of the control unit 41, and is switched by an installer who installs the humidification system 100 to set a target rotation speed for the motor 58. The rotation speed setting switch 50 supplies the set target rotation speed to the control unit 41. The rotation speed setting switch 50 may be configured to allow selection of one of a plurality of target rotation speeds that are set in stages in advance, or may be configured to allow the target rotation speed to be set continuously.

[0043] When the rotation speed of motor 58 detected by rotation speed detection unit 54 is lower than the target rotation speed, voltage control unit 42 controls the voltage applied to motor 58 so that the air volume blown by blower 12 approaches a predetermined target air volume. This control is called constant air volume control.

[0044] When the rotation speed of motor 58 detected by rotation speed detection unit 54 is equal to or greater than the target rotation speed, voltage control unit 42 controls the voltage applied to motor 58 so that the rotation speed of motor 58 approaches the target rotation speed. This control is called constant rotation speed control.

[0045] In this way, voltage control unit 42 switches between constant air volume control and constant rotation speed control depending on whether the rotation speed of motor 58 is equal to or greater than the target rotation speed.

[0046] The constant air volume control will be described in more detail. The memory unit 44 stores the relationship between the current and rotation speed of the motor 58 when the static pressure is changed from a predetermined minimum value to a predetermined maximum value at a predetermined target air volume. This relationship is measured in advance using a motor 58 with roughly standard characteristics. In this embodiment, the standard characteristics of the motor 58 mean that the current flowing through the motor 58 at the reference rotation speed is a standard value. Due to variations in characteristics due to individual differences in the motors 58, there may be motors 58 in which the current flowing through the motor 58 at the reference rotation speed is smaller than the standard value, and motors 58 in which the current flowing through the motor 58 at the reference rotation speed is greater than the standard value.

[0047] If the rotation speed of motor 58 is lower than the target rotation speed, voltage control unit 42 controls the voltage applied to motor 58 so that the detected current value and rotation speed of motor 58 approach the relationship between current and rotation speed for the target airflow stored in memory unit 44. If the rotation speed corresponding to the relationship stored in memory unit 44 for the detected current value of motor 58 is lower than the detected rotation speed of motor 58, voltage control unit 42 increases the applied voltage to increase the rotation speed. If the rotation speed corresponding to the relationship stored in memory unit 44 for the detected current value of motor 58 is equal to or higher than the detected rotation speed of motor 58, voltage control unit 42 decreases the applied voltage to decrease the rotation speed. As a result, if motor 58 has approximately standard characteristics, the airflow can be maintained at approximately the target airflow even if the static pressure changes. Known techniques can be used to control the constant airflow.

[0048] Fig. 4 shows an example of the relationship between static pressure and air volume at each of multiple rotation speeds of motor 58 in humidifier 10 of Fig. 1, and the relationship between static pressure and air volume at each of multiple air path resistances of duct 67. The horizontal axis of Fig. 4 represents air volume, and the vertical axis represents static pressure.

[0049] Relationship H1 shows the relationship between static pressure and air volume at a first rotation speed. Relationship H2 shows the relationship between static pressure and air volume at a second rotation speed that is greater than the first rotation speed. Relationship H3 shows the relationship between static pressure and air volume at a third rotation speed that is greater than the second rotation speed. Relationship H4 shows the relationship between static pressure and air volume at a fourth rotation speed that is greater than the third rotation speed. Relationship H5 shows the relationship between static pressure and air volume at a fifth rotation speed that is greater than the fourth rotation speed. In this embodiment, the fifth rotation speed is the maximum settable target rotation speed. As shown in the figure, when the rotation speed is constant, the air volume increases as the static pressure decreases.

[0050] Relationship R1 shows the relationship between static pressure and air volume when the air path resistance of duct 67 is a first resistance value. Relationship R2 shows the relationship between static pressure and air volume when the air path resistance is a second resistance value greater than the first resistance value. Relationship R3 shows the relationship between static pressure and air volume when the air path resistance is a third resistance value greater than the second resistance value. Relationship R4 shows the relationship between static pressure and air volume when the air path resistance is a fourth resistance value greater than the third resistance value. Relationship R5 shows the relationship between static pressure and air volume when the air path resistance is a fifth resistance value greater than the fourth resistance value. As shown in the figure, when the air path resistance is constant, the static pressure increases as the air volume increases.

[0051] FIG. 4 illustrates relationships H1 to H5 and relationships R1 to R5, but there may be more relationships between static pressure and air volume.

[0052] The lower limit airflow value Q1, the standard airflow value Q2, and the upper limit airflow value Q3 are determined in advance according to the specifications of the humidification system 100. The standard airflow value Q2 is, for example, several hundred m 3 The standard air volume value Q2 may be changeable by operating the operating device 70.

[0053] Target air volume Q4 is the maximum target rotational speed (fifth rotational speed) that can be set for motor 58, and is smaller than air volume Q10 sent by blower 12 when air path resistance is minimum (zero). This air volume Q10 is shown in FIG. 5, which will be described later. Target air volume Q4 is set as appropriate through experiments and simulations.

[0054] The target air volume Q4 is set so that when the rotation speed of the motor 58 detected by the rotation speed detection unit 54 is lower than the target rotation speed, the lower limit air volume value of the air volume variation caused by the characteristic variation of the motor 58 is larger than the lower limit air volume value Q1. This makes it possible to keep the air volume within the specification range even if the air volume decreases due to the characteristic variation of the motor 58.

[0055] FIG. 5 is a diagram for explaining control in the humidifier 10 of FIG. 1 when the target rotation speed is set to the fifth rotation speed and when the air path resistance is the fifth resistance value and the first resistance value.

[0056] Here, we assume that the fifth rotation speed was selected because the design value of the airflow resistance is the fifth resistance value. If the actual airflow resistance is also the fifth resistance value, the airflow will be controlled to the intersection P1 of the relationship H5 and the relationship R5. The airflow at the intersection P1 is a value near the standard airflow value Q2.

[0057] On the other hand, suppose that the specifications of duct 67 were changed after the design value of the airflow resistance was calculated, or that the design value was calculated incorrectly, resulting in the actual airflow resistance being the first resistance value. In this case, in the comparative example in which only constant rotation speed control is performed, unlike in Example 1, the airflow is controlled to the intersection P2 of relationship H5 and relationship R1. Because this airflow is significantly greater than the upper limit airflow value Q3 in the specifications, there is a possibility that the amount of humidification and the amount of released hypochlorous acid will be too high, as described above.

[0058] In the first embodiment, when the actual airflow resistance is the first resistance value, the constant airflow control controls the airflow to the target airflow Q4. That is, the airflow is controlled to the airflow at point P3 on the relationship R1. Therefore, if the set target rotation speed is higher than the target rotation speed that matches the actual airflow resistance, the airflow can be prevented from becoming too large. This also prevents the amount of humidification and the amount of released hypochlorous acid from becoming too large.

[0059] The subject of the device, system, or method disclosed herein includes a computer. The computer executes a program to realize the functions of the subject of the device, system, or method disclosed herein. The computer includes, as its main hardware component, a processor that operates according to the program. The processor may be of any type, as long as it can realize the functions by executing the program. The processor may be composed of one or more electronic circuits, including a semiconductor integrated circuit (IC) or a large-scale integration (LSI). The electronic circuits may be integrated into a single chip or may be provided on multiple chips. The multiple chips may be integrated into a single device or may be provided on multiple devices. The program is recorded on a non-transitory recording medium, such as a computer-readable read-only memory (ROM), optical disk, or hard disk drive. The program may be pre-stored on the recording medium or may be supplied to the recording medium via a wide-area communication network, including the Internet.

[0060] The operation of the humidification system 100 configured as described above will now be described. FIG. 6 is a flowchart showing the processing of the voltage control unit 42 of FIG. 3. The processing of FIG. 6 starts when the power of the humidification system 100 is turned on. The voltage control unit 42 applies an initial setting voltage to the motor 58 (S10), and acquires the rotation speed of the motor 58 after a predetermined time (S12). The initial setting voltage and the predetermined time can be determined appropriately through experiments or simulations. If the rotation speed of the motor 58 is lower than the target rotation speed (Y in S14), the voltage control unit 42 acquires the current value and rotation speed of the motor 58 (S16), and controls the duty ratio of the pulse width modulation signal so that the acquired current value and rotation speed approach the relationship between the current and rotation speed at the target airflow stored in the memory unit 44 (S18), and then returns to S12.

[0061] If the rotation speed of the motor is equal to or greater than the target rotation speed in S14 (N in S14), the voltage control unit 42 acquires the rotation speed of the motor 58 (S22), controls the duty ratio of the pulse width modulation signal so that the rotation speed of the motor 58 approaches the target rotation speed (S24), and returns to S12.

[0062] According to this embodiment, when the rotation speed of the motor 58 is lower than the target rotation speed, the applied voltage is controlled so that the air volume approaches the target air volume. Therefore, when the set target rotation speed is higher than the target rotation speed that matches the air path resistance, the air volume can be prevented from becoming too large.

[0063] Furthermore, when the rotation speed of motor 58 is equal to or higher than the target rotation speed, the applied voltage is controlled so that the rotation speed of motor 58 approaches the target rotation speed. Therefore, if the set target rotation speed is appropriate for the air path resistance, the desired air volume within the specification range can be obtained regardless of variations in the characteristics of motor 58.

[0064] Therefore, when a target rotation speed that matches the air path resistance is set, a desired air volume can be obtained regardless of variations in the characteristics of the motor 58, and when a target rotation speed higher than the target rotation speed that matches the air path resistance is set, the air volume can be prevented from becoming too large.

[0065] Example 2 In the second embodiment, when the set target rotation speed is lower than a predetermined lower limit value of the rotation speed, constant rotation speed control is executed without executing constant air volume control, which is different from the first embodiment. The following description will focus on the differences from the first embodiment.

[0066] FIG. 7 shows an example of a range A1 of static pressure and air volume within which constant air volume control is performed between the upper and lower limits of the characteristic variation of the motor 58 in the humidification system 100 of the second embodiment. For convenience of explanation, FIG. 7 shows relationships H11 to H14 instead of relationships H1 to H5 in FIG. 4, and relationships R11 to R14 instead of relationships R1 to R5 in FIG. 4. For example, relationship H11 shows the relationship between static pressure and air volume at a first rotation speed. Relationship H14 shows the relationship between static pressure and air volume at a fourth rotation speed. In this embodiment, the maximum target rotation speed that can be set is the fourth rotation speed, and the minimum target rotation speed that can be set is the first rotation speed. Relationship R11 shows the relationship between static pressure and air volume when the air path resistance is a first resistance value. Range A1 is the range surrounded by relationships Qn, Qx, Hn, H14, and the line where static pressure is zero.

[0067] The relationship Qn represents the relationship between static pressure and air volume when constant air volume control is performed and the characteristic variation of motor 58 is "+10%." The characteristic variation of "+10%" means that the current flowing through motor 58 at the reference rotation speed is 10% greater than the standard value.

[0068] The relationship Qx represents the relationship between static pressure and air volume when constant air volume control is performed and the characteristic variation of motor 58 is "-10%." A characteristic variation of "-10%" indicates that the current flowing through motor 58 at the reference rotation speed is 10% smaller than the standard value.

[0069] Although not shown, there are multiple relationships between static pressure and air volume when the characteristic variation of motor 58 is between 0% and +10% between relationship Qn and the dashed line indicating target air volume Q4. Also, there are multiple relationships between static pressure and air volume when the characteristic variation of motor 58 is between 0% and -10% between relationship Qx and the dashed line indicating target air volume Q4.

[0070] The relationship Hn shows the relationship between static pressure and airflow when the target rotation speed is at the lower limit. The lower limit is greater than the smallest settable target rotation speed (first rotation speed). When the rotation speed of motor 58 is at the lower limit and the static pressure is zero, the airflow is the target airflow Q4.

[0071] When the target rotation speed is lower than the lower limit value of the rotation speed, even if the rotation speed of motor 58 detected by rotation speed detection unit 54 is lower than the target rotation speed, voltage control unit 42 controls the voltage applied to motor 58 so that the rotation speed of motor 58 approaches the target rotation speed.

[0072] For example, when the target rotation speed is set to a first rotation speed that is lower than the lower limit of the rotation speed, constant rotation speed control is executed, and the air volume is controlled to the value on the relationship H11 according to the air path resistance. For example, if the air path resistance is the first resistance value, the air volume blown by blower 12 becomes the standard air volume value Q2, which is the intersection of the relationship H11 and the relationship R11, regardless of the characteristic variation of motor 58.

[0073] 7, if the control of Example 1 is performed, when the target rotation speed is set to the first rotation speed, if the air path resistance is the first resistance value and the characteristic variation of motor 58 is +10%, constant air volume control is performed, and the air volume sent by blower 12 becomes a value near lower limit air volume value Q1, which is the intersection of an extension line (not shown) of relationship Qn and relationship R11. That is, in this case, the air volume in Example 1 is smaller than that in Example 2.

[0074] Thus, according to the second embodiment, when a target rotation speed lower than the lower limit value of the rotation speed is set, it is possible to prevent the air volume from becoming too small due to variations in the characteristics of the motor 58.

[0075] Example 2A Furthermore, as an alternative to Example 2A of Example 2, a case will be described in which the combined control of constant rotation speed control and constant air volume control as in Example 1 is not performed. Differences from Example 2 will be mainly described below with reference to FIG. 7. Some of the definitions of symbols in FIG. 7 are different between Example 2 and Example 2A, and these will also be described. In Example 2A, voltage control unit 42 performs constant air volume control, which controls the voltage applied to motor 58 so that the volume of air blown by blower 12 approaches a predetermined target air volume. For example, air volume Q4 is set as the target air volume, and voltage control unit 42 performs constant air volume control, which controls the voltage applied to motor 58 so that the volume of air blown by blower 12 approaches target air volume Q4.

[0076] The relationship Qn shows the relationship between static pressure and air volume when constant air volume control is being performed and the characteristic variation of motor 58 is "+10%." The characteristic variation of "+10%" means that the current flowing through motor 58 at the reference rotation speed is 10% greater than the standard value.

[0077] The relationship Qx shows the relationship between static pressure and air volume when constant air volume control is being performed and the characteristic variation of motor 58 is "-10%." A characteristic variation of "-10%" means that the current flowing through motor 58 at the reference rotation speed is 10% smaller than the standard value.

[0078] Although not shown, there are multiple relationships between static pressure and air volume when the characteristic variation of motor 58 is between 0% and +10% between relationship Qn and the dashed line indicating target air volume Q4. Also, there are multiple relationships between static pressure and air volume when the characteristic variation of motor 58 is between 0% and -10% between relationship Qx and the dashed line indicating target air volume Q4.

[0079] Relationship Hn represents the relationship between static pressure and air volume when the rotation speed of motor 58 is at its lower limit. The lower limit of rotation speed is preferably a rotation speed at which the air volume becomes the target air volume Q4 when motor 58 of blower 12 is rotated at the lower limit of rotation speed and the static pressure is zero. However, the lower limit of rotation speed may also be a rotation speed at which the air volume becomes equal to or less than the target air volume Q4 when motor 58 of blower 12 is rotated at the lower limit of rotation speed and the static pressure is zero.

[0080] When controlling the voltage applied to the motor 58 to approach the target air volume Q4, if the rotation speed of the motor 58 detected by the rotation speed detection unit 54 is lower than the lower limit rotation speed, the voltage control unit 42 performs a first correction control to control the voltage applied to the motor 58 so that the rotation speed of the motor 58 becomes the lower limit rotation speed.

[0081] For example, if there is no characteristic variation in motor 58, the airflow volume blown by blower 12 when the airflow path resistance is the first resistance value and constant airflow volume control is executed is Q4. On the other hand, if the airflow path resistance is the first resistance value and the characteristic variation in motor 58 is +10%, and constant airflow volume control is executed, the airflow volume blown by blower 12 will be a value near airflow volume Q1, which is the intersection of an extension line (not shown) of relationship Qn and relationship R11, if the first correction control is not executed. However, if voltage control unit 42 executes first correction control, the airflow volume blown by blower 12 will be a value near airflow volume Q3, which is the intersection of relationship Hn and relationship R11. When voltage control unit 42 executes first correction control, the airflow volume blown by blower 12 can be closer to target airflow volume Q4. That is, deviation of the airflow volume blown by blower 12 from the target airflow volume due to variation in motor characteristics can be suppressed.

[0082] Thus, according to Example 2A, it is possible to prevent the air volume from becoming too small due to the characteristic variation of the motor 58. Therefore, it is possible to use an inexpensive motor 58 with a relatively large characteristic variation of about +10% while suppressing deviation of the air volume from the target air volume, thereby reducing the cost of the humidification system 100.

[0083] Example 3 The third embodiment differs from the second embodiment in that the current value of the motor 58 is limited to an upper current limit value. The following description will focus on the differences from the second embodiment.

[0084] 8 shows an example of a range A1a of static pressure and air volume in which constant air volume control is performed between the upper and lower limits of the characteristic variation of the motor 58 in the humidification system 100 of the third embodiment. The range A1a is the range surrounded by the relationship Qn, the relationship Hn, the relationship C1, the relationship H14, and the line where the static pressure is zero. The range A1a is the range A1 of the second embodiment minus the range A2. The relationship C1 shows the relationship between static pressure and air volume when the current value of the motor 58 is the upper current limit value.

[0085] When the current value of the motor 58 detected by the current detection unit 52 reaches a predetermined upper current limit value, the voltage control unit 42 controls the voltage applied to the motor 58 so that the current value of the motor 58 is maintained at the upper current limit value.

[0086] For example, if the characteristic variation of motor 58 is −10% and the target rotation speed is set to the fourth rotation speed, and if the airflow path resistance is the first resistance value, the air volume blown by blower 12 is controlled to the air volume at the intersection of relationship C1 and relationship R11. This is because the current value of motor 58 is limited to the upper current limit value.

[0087] On the other hand, assuming that the control of Example 2 is performed under the same conditions, the current value of motor 58 is not limited, and therefore the air volume blown by blower 12 is the air volume at the intersection of relationship H14 and relationship R11. That is, in this case, the air volume in Example 2 is larger than that in Example 3.

[0088] Thus, according to the third embodiment, it is possible to prevent the air volume from becoming too large due to variations in the characteristics of the motor 58. Therefore, it is possible to use an inexpensive motor 58 with a relatively large characteristic variation of about ±10% while suppressing the maximum air volume, thereby reducing the cost of the humidification system 100. In addition, it is possible to reduce power consumption.

[0089] Here, the upper current limit is equal to or greater than the current value of motor 58 when the air volume blown by blower 12 reaches upper air volume limit Q3 in the specifications when the rotation speed of motor 58 is the maximum settable target rotation speed. In the example of Fig. 8, the upper current limit is equal to the current value of motor 58 when upper air volume limit Q3 is reached according to relationship H14, i.e., the current value of motor 58 at intersection P10. This prevents the air volume from becoming too large due to variations in the characteristics of motor 58, without affecting air volume values ​​below upper air volume limit Q3 in the specifications due to the current limit.

[0090] Example 3A Also, as a separate example from Example 3, Example 3A will be described, which does not perform the combined control of constant rotation speed control and constant air volume control as in Example 1. Differences from Example 3 will be mainly described below with reference to FIG. 8. Some of the definitions of symbols in FIG. 8 are different between Example 3 and Example 3A, and these will also be described. In Example 3A, voltage control unit 42 performs constant air volume control, which controls the voltage applied to motor 58 so that the volume of air blown by blower 12 approaches a predetermined target air volume. For example, air volume Q4 is set as the target air volume, and voltage control unit 42 performs constant air volume control, which controls the voltage applied to motor 58 so that the volume of air blown by blower 12 approaches target air volume Q4.

[0091] Range A1a is the range obtained by excluding range A2 from range A1 in Example 2A. Relationship C1 shows the relationship between static pressure and air volume when the current value of motor 58 is the upper current limit value.

[0092] When controlling the voltage applied to the motor 58 to approach the target air volume Q4, if the current value of the motor 58 detected by the current detection unit 52 reaches a predetermined upper current limit value, the voltage control unit 42 performs a second correction control to control the voltage applied to the motor 58 so that the current value of the motor 58 remains at the upper current limit value.

[0093] The upper current limit is preferably the current value of motor 58 when the air volume blown by blower 12 reaches a lower limit air volume (e.g., air volume Q3) set by the specifications when the rotation speed of motor 58 is at the upper limit (e.g., the fourth rotation speed). However, the upper current limit may be equal to or greater than the current value of motor 58 when the air volume blown by blower 12 reaches the lower limit air volume (e.g., air volume Q3) set by the specifications when the rotation speed of motor 58 is at the upper limit. In the example of FIG. 8, the upper current limit is equal to the current value of motor 58 when the air volume reaches the lower limit air volume Q3 according to relationship H14, i.e., the current value of motor 58 at intersection P10. This prevents the air volume from becoming too large due to variations in the characteristics of motor 58, without affecting air volume values ​​below the lower limit air volume Q3 set by the specifications due to current limitation.

[0094] For example, if there is no characteristic variation in motor 58, the airflow volume blown by blower 12 when the airflow path resistance is the first resistance value and constant airflow volume control is executed is Q4. On the other hand, if the airflow path resistance is the first resistance value, the characteristic variation in motor 58 is −10%, and constant airflow volume control is executed, the airflow volume blown by blower 12 when the airflow path resistance is the first resistance value and constant airflow volume control is executed is the airflow volume at the intersection of an extension line (not shown) of relationship Qx and relationship R11 if the second correction control is not executed. However, if voltage control unit 42 executes second correction control, the airflow volume blown by blower 12 is controlled to the airflow volume at the intersection of relationship C1 and relationship R11. This is because the current value of motor 58 is limited to the upper current limit value. When voltage control unit 42 executes second correction control, the airflow volume blown by blower 12 can be closer to target airflow volume Q4. That is, it is possible to suppress deviation of the airflow volume blown by blower 12 from the target airflow volume due to variation in motor characteristics.

[0095] Thus, according to Example 3A, it is possible to prevent the air volume from becoming too large due to variations in the characteristics of the motor 58. Therefore, it is possible to use an inexpensive motor 58 with a relatively large characteristic variation of about -10% while suppressing deviation of the air volume from the target air volume, thereby reducing the cost of the humidification system 100. In addition, power consumption can be reduced.

[0096] The present disclosure has been described above based on examples. These examples are merely illustrative, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component or each treatment process, and that such modifications are also within the scope of the present disclosure.

[0097] For example, in Examples 1 to 3, humidifier 14 sprays water containing an air purifying component, but the sprayed water does not have to contain an air purifying component. In this case, the humidification method used by humidifier 14 is not particularly limited, and an evaporation method or the like may be used. Also, Example 3 may be combined with Example 1.

[0098] An overview of one aspect of the present disclosure is as follows. An air blowing system (100) according to one aspect of the present disclosure includes a housing (1) having an inlet (2) and an outlet (3), a duct (67) extending from the outlet (3), a blower (12) that blows air drawn in through the inlet (2) into the duct (67) via the outlet (3), a voltage control unit (42) that controls a voltage applied to a motor (58) of the blower (12), and a rotation speed detection unit (54) that detects the rotation speed of the motor (58). The voltage control unit (42) controls the voltage applied to the motor (58) so that the volume of air blown by the blower (12) approaches a predetermined target volume of air, and, when the rotation speed of the motor (58) detected by the rotation speed detection unit (54) is lower than a predetermined lower limit of the rotation speed, controls the voltage applied to the motor (58) so that the rotation speed of the motor (58) becomes the lower limit of the rotation speed.

[0099] The lower limit of the rotational speed may be a rotational speed at which the air volume when the motor (58) of the blower (12) is rotated at the lower limit of the rotational speed with the static pressure at zero is equal to or less than the target air volume.

[0100] Another aspect of the present disclosure is outlined as follows: A ventilation system (100) according to an aspect of the present disclosure includes a housing (1) having an inlet (2) and an outlet (3), a duct (67) extending from the outlet (3), a blower (12) that blows air drawn in through the inlet (2) into the duct (67) via the outlet (3), a voltage control unit (42) that controls a voltage applied to a motor (58) of the blower (12), a rotation speed detection unit (54) that detects the rotation speed of the motor (58), and a current detection unit (52) that detects a current value of the motor (58). The voltage control unit (42) controls the voltage to be applied to the motor (58) so that the volume of air blown by the blower (12) approaches a predetermined target volume of air, and when the current value of the motor (58) detected by the current detection unit (52) reaches a predetermined upper current limit, controls the voltage to be applied to the motor (58) so that the current value of the motor (58) is maintained at the current upper limit.

[0101] The upper current limit may be equal to or greater than the current value of the motor (58) when the air volume blown by the blower (12) reaches a lower limit air volume value determined by the specifications when the rotation speed of the motor (58) is at the upper rotation speed limit. [Industrial Applicability]

[0102] The ventilation system according to the present disclosure is useful as a system for blowing air into a target space. [Explanation of symbols]

[0103] 1 enclosure, 2, 2a, 2c suction port, 3,3a,3c outlet, 5 Purifying air passages, 8a, 8c, 9a, 9c Air, 10 humidifier, 11 HEPA filters, 12 blowers, 14 Humidification unit, 19 Hypochlorous acid water generation unit, 20 electrolyzer, 23 saltwater tank, 40 Temperature and humidity sensor, 41 control section, 42 voltage control section, 44 Memory section, 50 RPM setting switch, 52 current detection unit, 54 rotation speed detection unit, 56 drive unit, 58 motors, 62 indoor spaces, 64a, 64c duct, 65a, 65c Indoor intake port, 67 ducts, 67a, 67c Low-reactivity ducts, 68a,68c indoor air outlet, 70 Operating device; 72 Temperature and humidity sensor, 100 Humidification System

Claims

1. a housing having an inlet and an outlet; a duct extending from the air outlet; a blower that blows air drawn in through the suction port into the duct through the air outlet; a voltage control unit that controls a voltage applied to the motor of the fan; a rotation speed detection unit that detects the rotation speed of the motor; a current detection unit that detects a current value of the motor, The voltage control unit controlling a voltage applied to the motor so that the volume of air blown by the blower approaches a predetermined target volume of air; When the rotation speed of the motor detected by the rotation speed detection unit is lower than a predetermined lower limit value of the rotation speed, the voltage applied to the motor is controlled so that the rotation speed of the motor becomes the lower limit value of the rotation speed; When the current value of the motor detected by the current detection unit reaches a predetermined current upper limit value, the voltage applied to the motor is controlled so that the current value of the motor is maintained at the current upper limit value; The upper limit of the current is A ventilation system characterized in that, when the rotation speed of the motor is at the upper rotation speed limit, the current value of the motor is equal to or greater than the value when the air volume blown by the blower reaches the lower air volume limit value specified by the specifications.

2. The rotation speed lower limit value is 2. The air blowing system according to claim 1, wherein the rotation speed is set so that the air volume when the motor of the air blower is rotated at the rotation speed lower limit value when the static pressure is zero and the rotation speed is set to be equal to or less than the target air volume.

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