JP7769855B2 - ventilation system - Google Patents

Description

This disclosure relates to a ventilation system that blows air into a space.

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 through an air duct by the air blower and then released into the target area from an outlet (see, for example, Patent Document 1).

WO 20/158850

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.

This disclosure has been made in light of these circumstances, and its purpose is to provide technology that suppresses deviations 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.

In order to solve the above problems, a ventilation system according to one embodiment of the present disclosure includes a housing having an intake port and an exhaust port, a duct extending from the exhaust port, a blower that blows air drawn in through the intake port into the duct via the exhaust port, a voltage control unit that controls the voltage applied to the blower motor, a rotation speed detection unit that detects the rotation speed of the motor , and a current detection unit that detects the current value of the motor .

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

In addition, any combination of the above components, and conversions of the expressions of this disclosure between methods, devices, systems, etc., are also valid aspects of this disclosure.

This disclosure makes it possible to suppress deviations of the air volume blown by the blower from the target air volume due to variations in motor characteristics when performing constant air volume control.

1 is a diagram illustrating a configuration of a humidification system according to a first embodiment. FIG. 2 is a diagram showing the configuration of the humidifier shown in FIG. 1; FIG. 2 is a diagram showing a configuration related to control of a blower of the humidifier of FIG. 1 . 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. 1. FIG. 4 is a diagram for explaining control when the air path resistance is a fifth resistance value and a first resistance value when the target rotation speed is set to a fifth rotation speed in the humidifier of FIG. 4 is a flowchart showing the process of the voltage control unit in FIG. 3 . 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 characteristic variation of the motor in the humidification system of Example 2. 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 Example 3. FIG.

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 an "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. For example, hypochlorous acid, which has bactericidal or deodorizing properties, is used as the air purification component. This sterilizes or deodorizes the room.

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 blower motor is controlled to achieve that target rotation speed, if a target rotation speed higher than the target rotation speed that matches the actual air path resistance is set, the air volume may exceed the upper limit of the specifications. If the air volume is too high, it may become over-humidified or too much hypochlorous acid may be released into the air.

In this embodiment, when the motor rotation speed is lower than the target rotation speed, the voltage applied to the motor is controlled so that the airflow approaches the target airflow, and when the motor rotation speed 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 prevents the airflow from becoming too large when a target rotation speed higher than the target rotation speed that matches the air path resistance is set.

The examples described below each represent 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, any component not recited in an independent claim that represents the highest concept of the present disclosure will be described as an optional component. Furthermore, in each figure, substantially identical components are assigned the same reference numerals, and redundant explanations will be omitted or simplified.

Figure 1 shows the configuration of a humidification system 100 according to a first embodiment. The humidification system 100 is a device that adds air purification ingredients along with atomized water to air (RA) from an indoor space 62 when circulating the air in the indoor space 62. As mentioned 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 to the indoor space 62. Here, hypochlorous acid is used as the air purification ingredient, and the water containing the air purification ingredient is hypochlorous acid water.

As shown in FIG. 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 an air purification device. In this embodiment, the low-reactivity duct 67a and the low-reactivity duct 67c are collectively referred to as duct 67.

Figure 2 shows the configuration of the humidifier 10 of Figure 1. As shown in Figure 2, the humidifier 10 includes a housing 1, a purification air duct 5, a humidifier unit 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 control unit 41.

As shown in FIG. 2, the housing 1 forms the outer shell of the humidifier 10. The housing 1 has an intake port 2a, an intake port 2c, an exhaust port 3a, and an exhaust port 3c. In this embodiment, the intake port 2a and the intake port 2c are collectively referred to as the intake port 2, and the exhaust port 3a and the exhaust port 3c are collectively referred to as the exhaust port 3.

As shown in FIG. 2, the intake port 2a and the intake port 2c are located on one side of the housing 1. The exhaust port 3a and the exhaust port 3c are located on the other side of the housing 1 (the side opposite to the one side of the housing 1).

Intake ports 2a and 2c are intake ports 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 unconditioned air of the indoor space 62, whose temperature is not regulated, or temperature-regulated air, whose temperature is regulated by an air conditioner or the like separately installed in the indoor space 62.

As shown in FIG. 1, air inlet 2a is connected to an indoor air inlet 65a provided on the ceiling or other surface of indoor space 62 via duct 64a. Air inlet 2c is connected to an indoor air inlet 65c provided on the ceiling or other surface of indoor space 62 via duct 64c. This allows air inlet 2a to draw air 8a from indoor space 62 into the humidifier 10 through indoor air inlet 65a. Air inlet 2c can draw air 8c from indoor space 62 into the humidifier 10 through indoor air inlet 65c.

It is also possible not to provide the indoor air inlet 65c. In this case, one end of the duct 64a may be connected to the indoor air inlet 65a, and the other end of the duct 64a may be branched and connected to the air inlet 2a and the air inlet 2c.

Air outlet 3a is an outlet that discharges air 9a (SA) that has circulated through the humidifier 10 into the indoor space 62. Air 9a contains finely divided hypochlorous acid water. Air outlet 3c is an outlet that discharges air 9c (SA) that has circulated through the humidifier 10 into the indoor space 62. Air 9c also contains finely divided hypochlorous acid water.

As shown in FIG. 1, the air outlet 3a is connected to an indoor air outlet 68a provided on the ceiling or other surface of the indoor space 62 via a low-reactivity duct 67a. The air outlet 3c is connected to an indoor air outlet 68c provided on the ceiling or other surface of the indoor space 62 via a low-reactivity duct 67c. This allows the air outlet 3a to blow air 9a that has circulated through the humidifier 10 out from the indoor air outlet 68a toward the indoor space 62. The air outlet 3c is able to blow air 9c that has circulated through the humidifier 10 out from the indoor air outlet 68c toward the indoor space 62.

Note that the air outlet 3a and the air outlet 3c are not distinguishable from each other; for example, the air outlet 3c need 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.

Low-reactivity duct 67a and low-reactivity duct 67c are both ducts connected downstream of purified air duct 5, and have inner walls made of a low-reactivity material that reacts poorly 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.

As shown in Figure 2, the purification air duct 5 is provided within the housing 1 and connects the intake 2 (intake 2a and intake 2c) to the outlet 3 (outlet 3a and outlet 3c).

The purified air duct 5 is an air duct through which both air 8a and air 8c flow. The purified air duct 5 can also be described as an air duct through which a mixture of air 8a and air 8c flows. The purified 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 located upstream of the blower 12, adjacent to its intake port (not shown). The humidifier 14 is located downstream of the blower 12, adjacent to its exhaust port (not shown). A temperature and humidity sensor 40 is also located between the HEPA filter 11 and the blower 12 in the purified 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 the control unit 41.

The HEPA filter 11 is an air filter that removes dirt, dust, and other particles from the air that flows into the humidifier 10, and outputs purified air. The HEPA filter 11 is located adjacent to the intake ports 2a and 2c.

The blower 12 is a device for transporting air that has passed through the HEPA filter 11 along the purified air duct 5 to the humidifier 14. The blower 12 generates the air flow in the purified 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 composed of a double-intake centrifugal fan. The centrifugal fan can have a known configuration and is driven by a motor (not shown). The blower 12 draws air through intake ports (not shown) located on the left and right sides of the humidifier 14, and transports the air to the humidifier 14 through an outlet port (not shown).

The air volume, i.e., the rotation speed, of the blower 12 is controlled in response to an output signal from the control unit 41. When the blower 12 is operating, air is sent to the humidifier unit 14.

The humidifier 14 is a unit for humidifying the air taken into the purification air duct 5. During humidification, the air taken in from the blower 12 is mixed with atomized water and hypochlorous acid. The humidifier 14 can also be called an atomization unit. The humidifier 14 atomizes the hypochlorous acid water generated by the hypochlorous acid water generator 19 using centrifugal crushing and releases it 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.

The humidifier 14 has a centrifugal crushing unit and a mixing tank (not shown). The humidifier 14 uses a humidifier motor (not shown) to rotate the centrifugal crushing unit, sucking up hypochlorous acid water stored in the mixing tank with centrifugal force, scattering, colliding, and crushing it in the surrounding area (centrifugal direction), and moistening the air passing through.

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 control unit 41. The amount of humidification can also be thought of as the amount of air purifying components added to the air. The control unit 41 controls the rotation speed of the centrifugal crushing unit based on the humidity measurement value detected by the temperature and humidity sensor 72.

The hypochlorous acid water generator 19 (electrolytic cell 20 and brine tank 23) is located upstream of the blower 12 in the purified air duct 5. The hypochlorous acid water generator 19 dilutes the brine (sodium chloride aqueous 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.

In other words, 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 typical device is used for the electrolytic cell 20, so a detailed description 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. For example, an aqueous solution containing sodium chloride, calcium chloride, magnesium chloride, etc. dissolved as a solute can be used. Hydrochloric acid is also acceptable. In this example, an aqueous chloride solution (salt water) in which sodium chloride is added to water is used as the electrolyte.

As shown in FIG. 1, an operating device 70 (including a temperature and humidity sensor 72) is installed on a wall of the indoor space 62. The operating device 70 is connected to the control unit 41 via a wired or wireless connection, and transmits at least the humidity setting value, the measured humidity value, and operation mode information to the control unit 41. 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.

Figure 3 shows the configuration related to the control of the blower 12 of the humidifier 10 of Figure 1. The humidifier 10 further includes 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. The control unit 41 includes a voltage control unit 42 and a memory unit 44.

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

The voltage control unit 42 controls the voltage applied to the motor 58 by outputting an instruction value to the drive unit 56. The drive unit 56 applies a voltage corresponding to the instruction value of the voltage control unit 42 to the motor 58, thereby driving the motor 58. Specifically, the drive unit 56 generates a pulse-width modulated signal with a duty ratio corresponding to the instruction value of the voltage control unit 42, smooths the signal, and applies the smoothed voltage to the motor 58.

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.

The rotation speed setting switch 50 is provided, for example, on the circuit board of the control unit 41, and is switched by an installer installing the humidification system 100 to set the target rotation speed of 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 multiple predetermined target rotation speeds in stages, or may be configured to allow the target rotation speed to be set continuously.

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

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

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

The constant air volume control will be explained 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 between 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.

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

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

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 lower the static pressure, the greater the air volume.

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.

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

The lower limit airflow value Q1, the standard airflow value Q2, and the upper limit airflow value Q3 are predetermined based on the specifications of the humidification system 100. The standard airflow value Q2 may be, for example, several hundred m ³ /h. The standard airflow value Q2 may be changeable by operating the operating device 70.

The target air volume Q4 is the maximum target rotational speed (fifth rotational speed) that can be set for the motor 58, and is smaller than the air volume Q10 blown by the blower 12 when the air path resistance is minimum (zero). This air volume Q10 is shown in Figure 5, which will be described later. The target air volume Q4 is set appropriately through experiments and simulations.

The target airflow rate 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 airflow rate value of the airflow variation caused by the characteristic variation of the motor 58 is greater than the lower limit airflow rate value Q1. This ensures that the airflow rate remains within the specified range even if the airflow rate decreases due to the characteristic variation of the motor 58.

Figure 5 is a diagram illustrating control in the humidifier 10 of Figure 1 when the target rotation speed is set to 5 and when the air path resistance is the 5th resistance value and the 1st resistance value.

Here, we assume that the fifth rotation speed was selected because the design value of the air path resistance is the fifth resistance value. If the actual air path 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 close to the standard airflow value Q2.

On the other hand, let's assume that the actual airflow resistance is the first resistance value because the specifications of duct 67 were changed after the design value of the airflow resistance was calculated, or because the design value was calculated incorrectly. In this case, in the comparative example which, unlike Example 1, only performs constant rotation speed control, 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 hypochlorous acid released will be too high, as mentioned above.

In Example 1, when the actual air path resistance is the first resistance value, the constant air flow control controls the air to the target air flow Q4. In other words, the air flow is controlled to the air flow 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 air path resistance, the air flow can be prevented from becoming too large. This also prevents the amount of humidification and the amount of hypochlorous acid released from becoming too large.

The subject of the device, system, or method disclosed herein comprises a computer. When this computer executes a program, the functions of the subject of the device, system, or method disclosed herein are realized. The computer's main hardware configuration is 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 is composed of one or more electronic circuits, including semiconductor integrated circuits (ICs) or large-scale integration (LSIs). Multiple electronic circuits may be integrated into a single chip, or may be provided on multiple chips. 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 disc, 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.

The operation of the humidification system 100 configured as described above will now be described. Figure 6 is a flowchart showing the processing of the voltage control unit 42 of Figure 3. The processing of Figure 6 begins when the humidification system 100 is powered on. The voltage control unit 42 applies an initial setting voltage to the motor 58 (S10) and, after a predetermined time, acquires the rotation speed of the motor 58 (S12). The initial setting voltage and the predetermined time can be determined as appropriate through experimentation or simulation. 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 current and rotation speed at the target airflow stored in the memory unit 44 (S18), and then returns to S12.

If the motor rotation speed is equal to or greater than the target rotation speed in S14 (N in S14), the voltage control unit 42 obtains 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.

In 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, if 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.

In addition, if the rotation speed of the motor 58 is equal to or higher than the target rotation speed, the applied voltage is controlled so that the rotation speed of the 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 specifications can be obtained regardless of variations in the characteristics of the motor 58.

Therefore, when a target rotation speed that matches the air path resistance is set, the 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.

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. The following mainly describes the differences from the first embodiment.

Figure 7 shows an example of the range A1 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 Example 2. For convenience of explanation, Figure 7 shows relationships H11 to H14 instead of relationships H1 to H5 of Figure 4, and relationships R11 to R14 instead of relationships R1 to R5 of Figure 4. For example, relationship H11 shows the relationship between static pressure and air volume at the first rotation speed. Relationship H14 shows the relationship between static pressure and air volume at the fourth rotation speed. In this example, the maximum settable target rotation speed is the fourth rotation speed, and the minimum settable target rotation speed is the first rotation speed. Relationship R11 shows the relationship between static pressure and air volume when the air path resistance is the first resistance value. Range A1 is the range surrounded by relationships Qn, Qx, Hn, H14, and the line where static pressure is zero.

Relationship Qn shows 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% greater than the standard value.

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% less than the standard value.

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

The relationship Hn shows the relationship between static pressure and air volume 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 air volume is target air volume Q4.

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

For example, if the target rotation speed is set to a first rotation speed that is lower than the lower limit rotation speed, constant rotation speed control is executed, and the air volume is controlled to the value on the relationship H11 that corresponds to the air path resistance. For example, if the air path resistance is the first resistance value, the air volume blown by the blower 12 will be the standard air volume value Q2, which is the intersection of the relationship H11 and the relationship R11, regardless of the variation in the characteristics of the motor 58.

On the other hand, assuming that the control of Example 1 is performed in the example of Figure 7, when the target rotation speed is set to the first rotation speed, the air path resistance is the first resistance value, and the characteristic variation of the motor 58 is +10%, constant air volume control is executed, and the air volume blown by the blower 12 becomes a value near the lower limit air volume value Q1, which is the intersection of the extension line (not shown) of the relationship Qn and the relationship R11. In other words, in this case, the air volume in Example 1 is smaller than that in Example 2.

In this way, according to Example 2, when a target rotation speed lower than the lower limit value is set, it is possible to prevent the air volume from becoming too small due to variations in the characteristics of the motor 58.

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, the voltage control unit 42 performs constant air volume control, which controls the voltage applied to the motor 58 so that the air volume blown by the blower 12 approaches a predetermined target air volume. For example, air volume Q4 is set as the target air volume, and the voltage control unit 42 performs constant air volume control, which controls the voltage applied to the motor 58 so that the air volume approaches the target air volume Q4.

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%." A characteristic variation of "+10%" means that the current flowing through motor 58 at the reference rotation speed is 10% greater than the standard value.

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% less than the standard value.

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

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

When controlling the voltage applied to the motor 58 to approach the target airflow 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 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.

For example, if there is no characteristic variation in the motor 58, the air volume blown by the blower 12 when the air path resistance is the first resistance value and constant air volume control is executed is Q4. On the other hand, if the air path resistance is the first resistance value, the characteristic variation in the motor 58 is +10%, and constant air volume control is executed, the air volume blown by the blower 12 will be a value near air 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 the voltage control unit 42 executes first correction control, the air volume blown by the blower 12 will be a value near air volume Q3, which is the intersection of relationship Hn and relationship R11. When the voltage control unit 42 executes first correction control, the air volume blown by the blower 12 can be closer to the target air volume Q4. In other words, deviation of the air volume blown by the blower 12 from the target air volume, due to variation in the motor characteristics, can be suppressed.

In this way, according to Example 2A, it is possible to prevent the air volume from becoming too small 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.

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.

Figure 8 shows an example of the static pressure and air volume range A1a 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 Example 3. Range A1a is the range surrounded by the relationship Qn, relationship Hn, relationship C1, relationship H14, and the line where the static pressure is zero. Range A1a is the range obtained by excluding range A2 from range A1 of Example 2. 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.

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

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 air path resistance is the first resistance value, the air volume blown by blower 12 will be 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.

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 will be the air volume at the intersection of relationship H14 and relationship R11. In other words, in this case, the air volume in Example 2 will be greater than that in Example 3.

In this way, according to Example 3, it is possible to prevent the air volume from becoming too large due to variations in the characteristics of the motor 58. Therefore, while suppressing the maximum air volume, it is possible to use an inexpensive motor 58 with a relatively large characteristic variation of approximately ±10%, thereby reducing the cost of the humidification system 100. In addition, power consumption can be reduced.

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 the 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 Figure 8, the upper current limit is equal to the current value of motor 58 when the 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 the upper air volume limit Q3 in the specifications due to current limitations.

Example 3A
Furthermore, 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 using 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, the voltage control unit 42 performs constant air volume control, which controls the voltage applied to the motor 58 so that the volume of air blown by the blower 12 approaches a predetermined target air volume. For example, air volume Q4 is set as the target air volume, and the voltage control unit 42 performs constant air volume control, which controls the voltage applied to the motor 58 so that the volume of air blown by the blower 12 approaches the target air volume Q4.

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 at the upper current limit.

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

The upper current limit is preferably 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 (e.g., 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 set by the specifications when the rotation speed of motor 58 is at the upper limit. In the example of Figure 8, the upper current limit is equal to the current value of motor 58 when the lower limit air volume 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 the lower limit air volume Q3 set by the specifications due to current limitations.

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

In this way, 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. It is also possible to reduce power consumption.

The present disclosure has been described above based on examples. These examples are merely illustrative, and those skilled in the art will understand 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.

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

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

The lower limit of the rotation speed may be the rotation speed at which the air volume when the motor (58) of the blower (12) is rotated at the lower limit of the rotation speed and the static pressure is zero is equal to or less than the target air volume.

An overview of another aspect of the present disclosure is as follows: A ventilation system (100) according to one aspect of the present disclosure includes a housing (1) having an air inlet (2) and an air outlet (3), a duct (67) extending from the air outlet (3), a blower (12) that blows air drawn in through the air inlet (2) into the duct (67) via the air outlet (3), a voltage control unit (42) that controls the 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 the current value of the motor (58). The voltage control unit (42) controls the voltage applied to the motor (58) so that the air volume blown by the blower (12) approaches a predetermined target air volume, 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 applied to the motor (58) so that the current value of the motor (58) remains at the upper current limit.

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 the lower limit air volume value set by the specifications when the rotation speed of the motor (58) is at the upper rotation speed limit.

The ventilation system disclosed herein is useful as a system for blowing air into a target space.

1 housing,
2, 2a, 2c suction port,
3, 3a, 3c outlet,
5 Purification air duct,
8a, 8c, 9a, 9c air,
10 humidifier,
11 HEPA filter,
12 blower,
14 humidification unit,
19 Hypochlorous acid water generating unit,
20 electrolytic cell,
23 salt water tank,
40 temperature and humidity sensor,
41 control unit,
42 voltage control unit,
44 Memory section,
50 RPM setting switch,
52 current detection unit,
54 rotation speed detection unit,
56 drive unit,
58 motor,
62 indoor spaces,
64a, 64c ducts,
65a, 65c indoor intake port,
67 duct,
67a, 67c Low reactivity ducts,
68a, 68c indoor air outlet,
70 operating device,
72 temperature and humidity sensor,
100 Humidification System

Claims (2)

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 current value when the air volume blown by the blower reaches the lower air volume limit value specified by the specifications. 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.