JP7187797B2 - Charging device - Google Patents

Description

The present invention relates to charging devices.

2. Description of the Related Art Conventionally, charging devices are known that generate corona discharge between a discharge electrode and a counter electrode to charge fine particles in the air. Such a charging device is used in an electrostatic precipitator that collects charged fine particles, an air purifier that uses ozone generated by electric discharge, and the like. When a substance such as oily smoke such as cigarette smoke adheres to the discharge electrode of such a charging device, it becomes difficult for discharge to occur, charging efficiency decreases, and dust collection performance and deodorization performance decrease. Therefore, a technique for maintaining the charging efficiency by performing a cleaning operation for removing deposits adhering to the discharge electrode has been disclosed (see Patent Documents 1 and 2, for example).

JP 2010-069450 A JP-A-11-151454

Here, when the amount of deposits adhering to the discharge electrode is small, there is almost no decrease in charging efficiency, so there is almost no need to perform the cleaning operation. Therefore, in the above-mentioned Patent Documents 1 and 2, the discharge current and the discharge voltage are measured as a criterion for starting the cleaning operation, and when the measured value exceeds a preset threshold value, it is determined that there are many deposits. Perform cleaning operation. However, the discharge current and the discharge voltage are likely to fluctuate due to differences in the operating environment such as the humidity level. , there is a problem that it is easy to make an erroneous judgment when making a judgment. In addition, since the discharge current and discharge voltage fluctuate greatly immediately after the start of operation, there is a problem that it takes time for the measured values used for determination to stabilize.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and is a charging device capable of shortening the time required for the determination while appropriately determining whether or not it is necessary to remove the deposits adhering to the discharge electrode. An object of the present invention is to provide a device, an electrostatic precipitator with a charging device, and an air cleaner.

In order to solve the above-described problems, an example of a charging device according to an embodiment of the present invention includes a discharge electrode, a counter electrode arranged to face the discharge electrode, a voltage applying section that applies a voltage to the discharge electrode, and a discharge electrode. A discharge voltage measurement unit that measures the discharge voltage value between the electrode and the counter electrode, a discharge current measurement unit that measures the discharge current value between the discharge electrode and the counter electrode, and a discharge resistance value between the discharge electrode and the counter electrode. A measurement unit including at least one of the discharge resistance measurement units that measure; a storage unit that stores changes over time in the measured values measured by the measurement unit; Determining whether or not there is a change point at which a change to a monotonous decrease or a change from a monotonous decrease to a monotonous increase is present, and if it is determined that there is a change point, it is determined that the amount of deposits adhering to the discharge electrode is large. and a determination unit.

According to an embodiment of the present invention, a charging device capable of appropriately and promptly determining whether or not it is necessary to remove deposits attached to a discharge electrode, an electrostatic precipitator equipped with the charging device, and can provide an air purifier.

FIG. 1 is a schematic configuration diagram of an air purifier according to an embodiment. FIG. 2 : is a schematic block diagram of the electrostatic precipitator of embodiment. FIG. 3 is a block diagram showing the configuration of the high-voltage power supply for charging section and the control board of the air cleaner of the embodiment. FIG. 4 is a flow chart showing the control procedure of the air purifier of the embodiment. FIG. 5 is a subroutine showing discharge resistance initial value storage processing of the air cleaner of the embodiment. FIG. 6 is a subroutine showing discharge resistance calculation processing of the air cleaner of the embodiment. FIG. 7 is a subroutine showing change point determination processing of the air cleaner of the embodiment. FIG. 8 is a subroutine showing cleaning mode operation processing of the air purifier of the embodiment. FIG. 9 is a subroutine showing maintenance notification processing for the air purifier of the embodiment. FIG. 10 is a diagram showing the relationship between the amount of contamination on the charge-portion discharge electrode and the voltage. FIG. 11 is a diagram showing a change in discharge characteristics after energization of a discharge electrode to which dirt adheres. FIG. 12 is a diagram showing a change in discharge characteristics after application of a discharge current when there is little dirt adhering. FIG. 13 is a diagram showing changes in discharge characteristics after energization of the discharge electrode when a large amount of dirt is adhered. FIG. 14 is a diagram showing changes in the charge amount of the discharge electrode to which dirt adheres according to the elapsed time. FIG. 15 is a diagram showing changes in the discharge resistance of the discharge electrode according to elapsed time. FIG. 16 is a diagram showing changes in monitor voltage according to elapsed time. FIG. 17 is a diagram showing changes in the discharge current of the discharge electrode according to elapsed time.

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. The same reference numerals are assigned to the same elements throughout the description of the embodiment. In the following embodiments, a charging device according to technology disclosed herein is applied to an electrostatic precipitator included in an air cleaner. However, the present invention is not limited to this, and the charging device according to the technology disclosed herein may be applied to, for example, an air cleaner that generates ozone by discharging.

FIG. 1 is a schematic configuration diagram of an air cleaner according to an embodiment, and FIG. 2 is a schematic configuration diagram of an electrostatic precipitator according to an embodiment. As shown in FIGS. 1 and 2, the air purifier 1 includes a suction port 2 for sucking indoor air, a pre-filter 3 for removing large dust from the sucked air, and a filter in the air passing through the pre-filter 3. a plurality of electric dust collectors 4 for collecting dust, a deodorizing filter 5 for deodorizing the air that has passed through the electric dust collector 4, a fan 6 (blower) arranged downstream of the deodorizing filter 5, A fan motor 7 that rotates the fan 6, a blowout port 8 that blows out the air cleaned by the prefilter 3, the electric dust collector 4, and the deodorizing filter 5 into the room, and a control that controls the electric dust collector 4 and the fan motor 7. a control board 9 having a portion 93; A high-voltage power supply 11 (power supply for dust collection) to be supplied, an operation display board 12 for operation start operation, operation stop operation, air volume setting, etc., and dust concentration of air sucked from the suction port 2 is detected. and a dust sensor 13 (dust detection means). The charging section high voltage power supply 10 supplies power individually to the charging section 41 provided in each of the plurality of electrostatic precipitators 4, that is, the plurality of charging sections 41. The charging section high voltage power supply 10 is supplied with power. That is the power supply section 94 of the present invention.

The air purifier 1 sucks indoor air from the suction port 2 by rotation of the fan 6 driven by the fan motor 7, and the air passes through the pre-filter 3, the electrostatic precipitator 4, and the deodorizing filter 5. The cleaned air is blown into the room from a blowout port 8. - 特許庁

The air cleaner 1 of this embodiment has three built-in electrostatic precipitators 4, but the number of electrostatic precipitators 4 is not limited to three, and may be one or two. , or four or more. The air volume setting of the air purifier 1 includes manual air volume setting for manually switching the air volume based on the operation of the operation display board 12, the detection signal of the dust sensor 13, the dust threshold value 1 and the dust threshold value stored in advance. 2 (dust threshold value 1<dust threshold value 2), and automatic air volume setting for automatically switching to an appropriate air volume, either one of which can be selected.

As shown in FIG. 2 , the electrostatic precipitator 4 includes a charge section 41 and a dust collection section 42 . The charging section 41 includes a charging section discharge electrode 41a having a thin or sharp shape such as a wire or a needle, and a flat charging section counter electrode 41b having a polarity different from that of the charging section discharge electrode 41a. are staggered. The dust collector 42 has a structure in which a large number of flat plate electrodes are arranged in parallel and electrically connected so that high voltages of different polarities are alternately applied. The high-voltage electrode 42b of the dust collection part has the same polarity, and the dust collection part collection electrode 42a has the same polarity as the counter electrode 41b of the charging part.

A high voltage is applied to the charging section discharge electrode 41 a and the charging section counter electrode 41 b of the charging section 41 from the power supply 14 via the power supply section 94 by the charging section high voltage power supply 10 . The charging section high-voltage power supply 10 is driven and controlled by a control section 93 mounted on the control board 9 via charging section switches 91a, 91b, and 91c.

A high voltage is applied from the power source 14 to the dust collecting portion collecting electrode 42 a and the dust collecting portion high voltage electrode 42 b of the dust collecting portion high voltage power supply 11 via the power supply portion 94 . The high-voltage power supply 11 for dust collection section is driven and controlled by a control section 93 mounted on the control board 9 via a dust collection section switch 92 .

The charging section high-voltage power supply 10 is provided in the same number as the built-in number of the electrostatic precipitator 4, and is connected to the charging section 41 of each electrostatic precipitator 4 in a one-to-one correspondence. There is one high-voltage power supply 11 for the dust collector, regardless of the number of built-in electric dust collectors 4, and all the dust collectors 42 are connected in parallel.

Next, the action of collecting dust in the electrostatic precipitator 4 will be described.

When a positive high voltage is applied to the charge section discharge electrode 41a of the charge section 41 and the charge section counter electrode 41b is connected to the ground electrode of the charge section high voltage power supply 10, corona discharge occurs, and electrons and electrons are generated between the electrodes. Air molecules are filled with positively charged ions. Among them, the electrons reach the charging section discharge electrode 41a and flow toward the charging section high-voltage power supply 10 . Assuming that the current in the entire charging section 41 at this time is 0.025 mA, ions are generated between the electrodes corresponding to this current value. In addition, the shape of the charging part discharge electrode 41a, for example, a wire diameter of 0.1 mm in the case of a wire shape, is used so that the voltage that stably causes corona discharge is less than 5 kV so that the current becomes 0.025 mA. Can be set.

When the dust passes through the space filled with positive ions, the amount of electric charge generated by the collision between the ions and the dust depends on the passage time and the strength of the electric field created by the charge-portion discharge electrode 41a and the charge-portion counter electrode 41b. Movement occurs and the dust is charged with a positive charge.

On the other hand, if a voltage of, for example, 5 kV is applied to the dust collection high voltage electrode 42b of the dust collection unit 42, and the dust collection electrode 42a is connected to the ground electrode of the high voltage power supply 11 for the dust collection unit, even if the distance between the two electrodes is 2 mm, For example, an electrostatic field of 25 kV/cm is created. When the dust positively charged in the charging section 41 moves to the dust collection section 42, it receives a force in the direction of being attracted to the dust collection section collection electrode 42a having the polarity opposite to that of the dust due to the electrostatic field.

The dust floating in the air immediately reaches the terminal velocity due to air resistance, and becomes uniform motion having velocity components in the direction of the flow and the direction of the dust collection part collection electrode 42a. The velocity component in the direction of the dust collection electrode 42a is proportional to the electric charge amount and the electric field strength of the dust, and within the passing time of the dust collection part 42 determined by the velocity in the flow direction and the depth of the dust collection part 42, The dust reaching the collecting electrode 42a is collected. Since the dust floating in the air is sufficiently small and is affected by diffusion, some of the dust moves away from the dust collection part collection electrode 42a, and all the dust is collected while passing through the dust collection part 42. Although it is not collected, dust that is not collected is repeatedly taken into the air cleaner 1 and passes through the electrostatic precipitator 4 during operation of the air cleaner 1, so it is not collected. The amount of dust that initially passes through the dust collecting section 42 decreases exponentially with the lapse of time from the start of operation of the air cleaner 1 .

Here, one of the methods for increasing the collection efficiency is to increase the amount of electric charge on the dust, that is, to increase the number of ions in the charge section 41 . In order to obtain a stable dust collection capability, the high-voltage power supply 10 for the charging section is required to have a characteristic of keeping the positive high voltage applied to the charging section discharge electrode 41a constant.

Another method for increasing the collection rate is to increase the strength of the electric field of the dust collection section 42, which is as high as possible within a range that does not cause abnormal discharge. In order to maintain the potential difference between them, the high-voltage power supply 11 for the dust collecting section is required to have the characteristic of keeping the output voltage constant. In addition, since the dust concentration of the air treated by the household air purifier is as low as 0.1 mg/m3, for example, the amount of electric charge of the dust collected by the dust collector 42 causes a small amount of electric current to flow. The current capacity of the power supply 11 may be as small as 0.01 mA, for example.

The amount of air to be processed, for example, 3 to 8 m3/min, required for a home air purifier can be handled by incorporating one to three electrostatic precipitators 4 corresponding to the high-voltage power supply 10 for charging section with the above output. However, the present invention is not limited to this, and the number of electrostatic precipitators 4 may be appropriately changed according to the required capacity of the air purifier, such as four or more. Alternatively, two or more charging units 41 may be provided, only one dust collecting unit 42 may be provided, and the plurality of charging units 41 may be arranged on the windward side of the dust collecting unit 42 .

Next, the high-voltage power supply 10 for charge section and the control board 9 of the air cleaner 1 of the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing the configuration of the high-voltage power supply for charging section and the control board of the air cleaner of the embodiment. The control board 9 includes a control unit for controlling a high-voltage power supply 10 for the charging section, a high-voltage power supply 11 for the dust collection section, and a fan motor power supply (not shown) that supplies power to the fan motor 7. 3 omits illustrations other than the control unit 93 that controls the high-voltage power supply 10 for the charging unit.

The charging section high voltage power supply 10 has an input section 10a, a boost section 10b, an output section 10c, a voltage detection section 10d, and a current detection section 10e. A DC power supply voltage of, for example, 12 V is input from the power supply 14 to the input unit 10a. The booster 10b boosts the DC power supply voltage input via the input unit 10a to a first voltage through switching control. The DC voltage boosted by the booster 10b is applied to the charging section discharge electrode 41a and the charging section counter electrode 41b of the charging section 41 via the output section 10c.

In addition, while the input unit 10a receives an input of a "cleaning mode operation signal" output from the control unit 93, the booster unit 10b is operated when the air cleaner 1 is turned off automatically or manually. , the DC power supply voltage input via the input section 10a is stepped up to a second voltage higher than the first voltage by switching control, and the charging section discharge electrode 41a of the charging section 41 via the output section 10c. and continues to be applied to the charging portion counter electrode 41b. In this way, in the air cleaner 1, the removal of deposits adhering to the charge part discharge electrode 41a is performed by sputtering with charged particles (by applying a high voltage to the discharge electrode, the charged particles cover the surface of the discharge electrode). By making a hole in the deposit and continuously applying a high voltage, the hole formed in the deposit gradually widens and the deposit is removed. be.

Here, the air purifier 1 of the embodiment is intended to collect not only dust having a low oil content and a dry property, but also greasy smoke such as cigarette smoke. For this reason, the adhering matter adhering to the charge-portion discharge electrode 41a becomes dust containing greasy smoke such as cigarette smoke.

Next, the control board 9 will be explained. The control board 9 has a control section 93 and a storage section 93d. The storage unit 93d is an internal storage device such as a volatile semiconductor storage device or a non-volatile external storage device using a semiconductor as a storage medium. The storage unit 93d stores a humidity conversion table (not shown). Since the discharge resistance changes according to the humidity, the humidity conversion table contains correction values for correcting the discharge resistance value at the current humidity obtained by the humidity sensor 93e to the discharge resistance value at a predetermined reference humidity. is a table stored in association with the humidity of . In addition, as described later, the storage unit 93d stores various measured values, acquired values, calculated values (discharge resistance initial value, voltage value/current value, discharge resistance value _Rt , etc.), a change point flag, a threshold excess flag, It has a storage area (not shown) for storing counters, various threshold values, and the like. Various measured values, acquired values, and calculated values are stored in the storage unit 93d in chronological order for each measurement timing, acquisition timing, and calculation timing.

The humidity sensor 93e is a sensor for acquiring the relative humidity around the outside of the air cleaner 1 . The notification unit 93f provides the user of the air purifier 1 with various types of information, which will be described later, including information indicating the operating state of the air purifier 1 and that the charging unit 41 is being continuously energized, and maintenance information. conduct. Alternatively, the notification unit 93f notifies that a deposit is adhered to the charge part discharge electrode 41a when there is a change point described later, and notifies the charge part discharge electrode 41a when there is no change point described later. Notifies that no deposit is attached. For example, the notification unit 93f includes an LED (Light Emitting Diode), a display, an audio output unit, and the like. The humidity sensor 93 e and the notification section 93 f are provided in the air cleaner 1 and connected to the control section 93 .

The control unit 93 is a processing device such as a microprocessor. The control unit 93 has a discharge resistance calculation unit 93a, a change point determination unit 93b, and an operation control unit 93c. The discharge resistance calculator 93a executes a discharge resistance initial value storage process (see FIG. 5) and a discharge resistance calculation process (see FIG. 6), which will be described later. The change point determination unit 93b executes change point determination processing (see FIG. 7), which will be described later. The operation control unit 93c controls operation of cleaning mode operation processing (see FIG. 8), maintenance notification processing (see FIG. 9), and air cleaning processing of the air purifier 1, which will be described later.

[Air purifier control procedure]
FIG. 4 is a flow chart showing the control procedure of the air purifier of the embodiment. The control procedure of the air cleaner 1 of the embodiment is executed by the control unit 93 when the operation of the air cleaner 1 is started. In the flow charts of FIGS. 4 to 9 below, as an example, a point where the discharge resistance changes from a monotonous increase to a monotonous decrease is defined as a change point, which will be described later. When the measured value to be checked for the presence or absence of the change point is the voltage (monitor voltage) of the charging section high voltage power supply 10, the mode of the change point is the same as that of the discharge resistance (see FIGS. 15 and 16 to be described later). ). On the other hand, when the measured value to be checked for the presence or absence of the change point is the discharge current of the charging section 41, the mode of the change point is the opposite of the characteristics of the discharge resistance, the point where monotonous decrease turns to monotonous increase. (See FIG. 17, which will be described later).

First, the operation control unit 93c of the control unit 93 starts the operation of the electrostatic precipitator 4 in response to the operation start of the air cleaner 1 (step S10). Next, the discharge resistance calculator 93a of the controller 93 executes a discharge resistance initial value storage process (step S20). The details of the discharge resistance initial value storage processing will be described later.

Next, the change point determination unit 93b of the control unit 93 resets these flags such that the change point flag=0 and the threshold excess flag=0 (step S30). Next, the discharge resistance calculator 93a executes discharge resistance calculation processing (step S40). Details of the discharge resistance calculation process will be described later.

Next, the change point determination unit 93b executes change point determination processing, which will be described later (step S50). Next, the operation control unit 93c determines whether or not an instruction to stop the operation of the air purifier 1 has been input (step S60). When an instruction to stop the operation of the air purifier 1 is input (step S60: Yes), the operation control unit 93c proceeds to step S70. On the other hand, if the instruction to stop the operation of the air purifier 1 has not been input (step S60: No), the operation control unit 93c proceeds to step S40.

Next, the change point determination unit 93b determines whether or not the change point flag=1 or the change point flag=2 (step S70). If the change point flag=1 or the change point flag=2 (step S70: Yes), the change point determination unit 93b moves the process to step S80. On the other hand, if neither the change point flag=1 nor the change point flag=2 (step S70: No), the change point determination unit 93b moves the process to step S90.

In step S80, the operation control section 93c outputs a cleaning mode operation signal to the high voltage power supply 10 for charging section. Next, the operation control unit 93c stops the operation of the electric dust collector 4 in response to the operation of the air cleaner 1 being stopped (step S90).

[Discharge resistance initial value memory processing of air purifier]
FIG. 5 is a subroutine showing discharge resistance initial value storage processing of the air cleaner of the embodiment. The discharge resistance calculation unit 93a determines whether or not the discharge resistance initial value is stored in the storage unit 93d (step S21). In step S21, when it is determined that the discharge resistance initial value is not stored in the storage unit 93d, it is determined that the air purifier 1 is used for the first time, and the discharge resistance initial value is stored in the storage unit 93d. If so, it is determined that the air purifier 1 is being used for the second time or later. When the discharge resistance initial value is stored in the storage unit 93d (step S21: Yes), the discharge resistance calculation unit 93a ends the discharge resistance initial value storage processing, and shifts the processing to step S30 in FIG. On the other hand, when the discharge resistance initial value is not stored in the storage unit 93d (step S21: No), the discharge resistance calculator 93a shifts the process to step S22.

In step S22, the discharge resistance calculator 93a determines whether or not the cumulative time of energization of the air purifier 1 has passed for a predetermined time (for example, 24 hours). In step S22, when the air purifier 1 is operated for the first time, the discharge characteristics of the charging section 41 are not stabilized due to the influence of burrs formed in the charging section discharge electrode 41a and the charging section counter electrode 41b during the manufacture of each, and the discharge resistance is adjusted with accuracy. Since it cannot be measured well, this processing waits until the cumulative time of energization of the air purifier 1 passes a predetermined time and the discharge characteristics become stable. When the cumulative time of energization of the air purifier 1 has passed for a predetermined time (for example, 24 hours) (step S22: Yes), the discharge resistance calculator 93a shifts the process to step S23. On the other hand, if the cumulative time of energization of the air purifier 1 has not passed a predetermined time (for example, 24 hours) (step S22: No), the discharge resistance calculator 93a repeats step S22.

In step S23, the discharge resistance calculator 93a determines whether or not the duration of current energization has passed for a predetermined time (for example, one hour) (step S23). Step S23 is when the air purifier 1 is used for the first time. This is a process of waiting for the continuation of current energization to pass a predetermined period of time and the discharge characteristics to stabilize. When the current energization duration has passed for a predetermined time (for example, one hour) (step S23: Yes), the discharge resistance calculator 93a shifts the process to step S24. On the other hand, the discharge resistance calculator 93a repeats step S23 when the continuation time of current energization has not passed a predetermined time (for example, one hour) (step S23: No). In step S23, the duration of current energization is not limited to one hour, and may be three to five minutes or one to ten minutes.

Next, the discharge resistance calculator 93a executes discharge resistance calculation processing (step S24). Details of the discharge resistance calculation process will be described later. Next, the discharge resistance calculation unit 93a executes discharge resistance initial value storage processing for storing the discharge resistance calculated in step S24 in the storage unit 93d (step S25).

[Discharge resistance calculation processing of air purifier]
FIG. 6 is a subroutine showing discharge resistance calculation processing of the air cleaner of the embodiment. The discharge resistance calculation process shown in FIG. 6 is a process executed in step S40 of FIG. 4, step S24 of FIG. 5, and step S81 of FIG.

First, the discharge resistance calculation unit 93a calculates the voltage value applied to the charging unit 41 detected by the voltage detection unit 10d via the output unit 10c, and the voltage value applied to the charging unit 41 detected by the current detection unit 10e via the output unit 10c. The discharge resistance value is calculated by calculating the voltage value/current value from the current value flowing through the charging section 41 (step S41). Next, the discharge resistance calculator 93a acquires the relative humidity via the humidity sensor 93e.

Next, based on the relative humidity obtained in step S42, the discharge resistance calculation unit 93a acquires a correction value for the discharge resistance value from a humidity conversion table (not shown) stored in the storage unit 93d. corrects the discharge resistance value calculated in step S41 (step S43). Next, the discharge resistance calculator 93a acquires 10 pieces of data acquired in steps S41 to S43 per minute, for example (step S44). Next, the discharge resistance calculator 93a calculates the average of the 10 data acquired in step S44, and sets the calculated average as the discharge resistance value _Rt (step S45). However, the suffix _t of the discharge resistance value Rt represents the elapsed time t [minutes] after the start of operation of the air cleaner 1, where t=1, 2, 3, . . . For example, _R1 is the discharge resistance value averaged for one minute immediately after the air cleaner 1 starts operating. When step S45 ends, the discharge resistance calculator 93a returns the process to any one of step S40 in FIG. 4, step S24 in FIG. 5, and step S81 in FIG.

[Change point determination processing of air purifier]
FIG. 7 is a subroutine showing change point determination processing of the air cleaner of the embodiment. First, the change point determination unit 93b determines whether or not the change point flag=0 (step S51). When the change point flag=0 (step S51: Yes), the change point determination unit 93b moves the process to step S52. On the other hand, if the change point flag is not 0 (step S51: No), the change point determination unit 93b proceeds to step S57.

In step S52, the change point determination unit 93b determines whether or not R ₂ >R ₁ and R ₃ >R ₂ . That is, in step S52, the change point determination unit 93b determines the discharge resistance value R ₁ at time t=1, the discharge resistance value R 2 at time t=2, and the discharge resistance value R ₂ at time t=3 after the operation of the air cleaner 1 is started. Regarding the resistance value R3 _, it is determined whether or not the discharge resistance value increases with the lapse of time. If R ₂ >R ₁ and R ₃ >R ₂ (step S52: Yes), the change point determination unit 93b proceeds to step S53. On the other hand, if R ₂ >R ₁ and R ₃ >R ₂ are not satisfied (step S52: No), the change point determination unit 93b proceeds to step S57.

In step S53, the change point determination unit 93b determines the discharge at each of the three latest consecutive times t=m−2, t=m−1, and t=m [minutes] after the start of operation of the air purifier 1. It is determined whether R _m-1 <R _m-2 and R _m <R _m-1 for the resistance values R _m-2 , R _{m -1} , and R m . That is, in step S53, the change point determination unit 93b determines the latest three discharge resistance values R _m , R _m−1 , and R _m−2 after the operation of the air purifier 1 is started. It is determined whether or not the discharge resistance value is decreasing over time. In step S53, it is determined whether or not the discharge resistance, which monotonously increased in step S52, monotonically decreases after taking a maximum value. If R _m-1 <R _m-2 and R _m <R _m-1 (step S53: Yes), the change point determination unit 93b in step S53 shifts the process to step S54. On the other hand, if R _m−1 <R _m−2 and R _m <R _m−1 are not satisfied (step S53: No), the change point determination unit 93b proceeds to step S57.

In step S54, the change point determination unit 93b determines whether or not the elapsed time t in step S53 is less than a predetermined threshold value T. The threshold T in this embodiment is a time corresponding to the amount of dirt that can be removed by the cleaning mode operation process. That is, in step S54, it is determined whether or not the time until the discharge resistance begins to monotonically decrease in step S53 is longer than the time corresponding to the amount of dirt that can be removed by the cleaning mode operation process. When the elapsed time t in step S53 is less than the predetermined threshold value T (step S54: Yes), the change point determination unit 93b shifts the process to step S55. When the elapsed time t in step S53 is equal to or greater than the predetermined threshold value T (step S54: No), the change point determination unit 93b shifts the process to step S56.

In step S55, the change point determination unit 93b sets the change point flag=1. Further, in step S56, the change point determination unit 93b sets the change point flag=2. For example, the discharge resistance increases in the first 3 minutes (t = 1, 2, 3) after the start of operation, and then for 3 minutes (t = n-2, n-1, n (n is If it continues to decrease at a certain time before the stop)), the amount of deposits adhering to the charging unit 41 depends on the time t when the change point was first determined (elapsed time when the operation start time is zero). The degree of quantity can be determined. In step S<b>54 , if the time t at which the change point was first determined<threshold value T (that is, the elapsed time until the change point occurs is within the range of the predetermined threshold value), then is an amount that can recover the charging efficiency by removing deposits on the charging section 41 in the cleaning mode operation process (that is, the amount of deposits is moderately large), and the change point flag = Set to 1. On the other hand, in step S54, if the time t at which the change point is first determined≧threshold value T (that is, the elapsed time t until the change point occurs is outside the range of the predetermined threshold value), Assuming that the amount of deposits present is such that the charging efficiency cannot be recovered by removing the deposits on the charging section 41 in the cleaning mode operation process (that is, the amount of deposits is very large), the change point Set flag=2. When step S55 or step S56 ends, the change point determination unit 93b ends the change point determination process, and moves the process to step S60 in FIG.

[Cleaning Mode Operation Processing of Air Purifier of Embodiment]
FIG. 8 is a subroutine showing cleaning mode operation processing of the air purifier of the embodiment. In the cleaning mode operation process of the air purifier of the embodiment, the operation control unit 93c, for example, minimizes the air volume of the air purifier 1 and performs A cleaning operation control signal is input to the high-voltage power supply 10 for charging section, and a voltage higher than that during normal operation of the air cleaner 1 is continuously applied to the charging section 41 . The mode of the cleaning mode operation is not limited to this, and any means for removing deposits from the charge section discharge electrode 41a may be used. Further, even if the air purifier 1 is turned off automatically or manually, the high-voltage power supply 10 for charging section applies a high voltage to the charging section 41 as long as the cleaning operation control signal is input.

First, the operation control unit 93c controls the discharge resistance calculation unit 93a to perform discharge resistance calculation processing (step S81). Next, the operation control unit 93c determines that the discharge resistance initial ratio, which is the ratio of the discharge resistance calculated in step S81 to the discharge resistance initial value calculated in step S20 of FIG. It is determined whether or not it is large (step S82). When the discharge resistance initial ratio is greater than threshold value 2 (step S82: Yes), the operation control unit 93c moves the process to step S83. On the other hand, when the discharge resistance initial ratio is equal to or less than the threshold value 2 (step S82: No), the operation control unit 93c ends the cleaning mode operation process and shifts the process to step S80 in FIG. This threshold value 2 may be, for example, the initial discharge resistance ratio in a state where dirt is not attached, and is 1.00 to 1.01 or 1.02 to 1.04 in this embodiment.

In step S83, the operation control unit 93c determines whether or not a predetermined time (for example, 6 hours) has passed since the cleaning mode operation process was started. The operation control unit 93c uses a timer to time a predetermined period of time. When a predetermined time has passed since the cleaning mode operation process was started (step S83: Yes), the operation control unit 93c moves the process to step S84. On the other hand, if the predetermined time has not elapsed since the start of the cleaning mode operation process (step S83: No), the operation control unit 93c moves the process to step S81.

In step S84, the operation control unit 93c determines whether or not the change point flag=1. When the change point flag is 1 (step S84: Yes), the operation control unit 93c proceeds to step S85. On the other hand, if the change point flag is not equal to 1 (step S84: No), the operation control unit 93c proceeds to step S84.

In step S85, the operation control unit 93c increments by +1 a counter that counts the number of times that the discharge characteristics have not been sufficiently recovered in the cleaning mode operation. Next, the operation control unit 93c determines whether or not the counter incremented by +1 in step S85 has a value greater than 10, for example (step S86). When the counter incremented by +1 in step S85 becomes a value larger than 10 (step S86: Yes), the operation control unit 93c shifts the process to step S84. On the other hand, if the counter incremented by +1 in step S85 is equal to or less than 10 (step S86: No), the operation control unit 93c ends the cleaning mode operation process and shifts the process to step S80 in FIG. .

In step S87, the operation control unit 93c executes maintenance notification processing. The maintenance notification process is performed when the removal of the deposits adhering to the charging part discharge electrode 41a due to voltage application to the charging part 41 is not expected and the discharge characteristics of the charging part discharge electrode 41a are not recovered. This is a process for notifying the user to manually remove the deposits adhering to the charge part discharge electrode 41a. Details of the maintenance notification process will be described later. When step S87 ends, the operation control unit 93c stops outputting the cleaning mode operation signal to the charging unit high voltage power supply 10, ends the cleaning mode operation process, and proceeds to step S80 in FIG.

Steps S82 and S83 indicate that the cleaning mode operation process is continued for a predetermined period of time (for example, 6 hours) when the initial discharge resistance ratio>threshold 2 (step S82: Yes). Even if the cleaning mode operation process is executed for a predetermined time (for example, 6 hours), the cleaning mode operation process is forcibly terminated when the termination condition is not satisfied in step S82. . However, if the change point flag is 1 in step S84 (dirt to the extent that adhering matter adhering to the charging section 41 can be removed by the cleaning mode operation process), the cleaning mode is set for a predetermined time (for example, 6 hours). If the termination condition is not satisfied in step S82 even after the operation process is continued for a predetermined number of times (for example, 10 times), the process proceeds to step S87 to notify of manual cleaning. In step S84, if the change point flag is 2 (dirt to the extent that the adhering matter attached to the charging section 41 cannot be removed by the cleaning mode operation process), the cleaning mode is set for a predetermined time (for example, 6 hours). The operation process is continued for a predetermined number of times (for example, once), and when the termination condition is not satisfied in step S82 for determining the end of the cleaning mode operation process, the process immediately proceeds to step S87 to notify of manual cleaning.

[Maintenance notification processing for air purifier according to the embodiment]
FIG. 9 is a subroutine showing maintenance notification processing for the air purifier of the embodiment. If the change point flag is 2 (dirt to the extent that the deposits attached to the charging section 41 cannot be removed by the cleaning mode operation process), sputtering cannot occur in the charging section 41, so please be careful. Maintenance is notified by maintenance notification processing. The change point flag is set to 2 when "t≧threshold T" in step S54 of FIG.

The operation control unit 93c instructs the user of the air cleaner 1 to manually operate the electric dust collector 4 via the display unit (not shown) or the audio output unit (not shown) of the operation display board 12. The user is notified to perform maintenance (cleaning) (step S87-1). Next, the operation control unit 93c initializes the counters used in steps S85 and S86 of FIG. 8 with counter=0 (step S87-2). When step S87-2 ends, the operation control unit 93c returns the process to FIG. 8 and moves the process to step S80 in FIG.

In addition, the air cleaner 1 may have a cleaning device including a brush or the like. Then, instead of step S87-1, the operation control section 93c may forcibly clean the charging section discharge electrode 41a of the electrostatic precipitator 4 with a cleaning device.

[Relationship between the amount of dirt on the discharge electrode and the voltage of the charged part]
FIG. 10 is a diagram showing the relationship between the amount of contamination on the charge-portion discharge electrode and the voltage. FIG. 10 is a diagram showing the relationship between the amount of dirt on the charging section discharge electrode 41a and the voltage of the charging section 41 when the input current of the charging section 41 is controlled to be constant. In FIG. 10, the horizontal axis indicates the amount of contamination of the charging section discharge electrode 41a in the positive direction, and the vertical axis indicates the magnitude of the voltage of the charging section 41 in the positive direction. As shown in FIG. 10, it can be seen that the voltage of the charging section 41 increases as the amount of dirt on the charging section discharge electrode 41a increases. When the input current of the charging section 41 is controlled to be constant, the voltage of the charging section 41 and the discharge resistance of the charging section 41 are in a proportional relationship. discharge resistance will rise. In other words, there is a positive correlation between the amount of dirt on the charging section discharge electrode 41 a and the discharge resistance of the charging section 41 .

[Change in discharge characteristics after energization of discharge electrode with dirt]
FIG. 11 is a diagram showing a change in discharge characteristics after energization of a discharge electrode to which dirt adheres. FIG. 11 is a diagram showing temporal (energization time) changes in the voltage (monitor voltage) of the charging section high voltage power supply 10 when the input current of the charging section 41 is controlled to be constant. In FIG. 11, the horizontal axis indicates the passage of time in the positive direction, and the vertical axis indicates the magnitude of the monitor voltage in the positive direction. As shown in FIG. 11, the monitor voltage, which once monotonously increased with the energization time, takes a maximum value (first change point) at an elapsed time of 30 minutes, for example, and then monotonically decreases. When the input current of the charge section 41 is controlled to be constant, the voltage of the charge section 41 and the discharge resistance of the charge section 41 are in a proportional relationship. Then, after taking the maximum value at the first change point and then monotonically decreasing, the discharge resistance of the charging section discharge electrode 41a first monotonically increases and after taking the maximum value at the first change point, , is equivalent to turning to monotonically decreasing.

[Change in discharge characteristics after application of discharge current when adhered dirt is small]
FIG. 12 is a diagram showing a change in discharge characteristics after application of a discharge current when there is little dirt adhering. FIG. 12 shows the discharge current time ( It is a diagram showing a change in energization time). In FIG. 12, the horizontal axis indicates the passage of time in the positive direction, and the vertical axis indicates the magnitude of the discharge current in the positive direction. As shown in FIG. 12, when the amount of deposits adhering to the charging section discharge electrode 41a is less than a predetermined amount, the discharge current monotonically increases with the energization time. It becomes a constant value in general. That is, when the input voltage of the charging section 41 is controlled to be constant, the voltage of the charging section 41 and the discharge current of the charging section 41 are in an inversely proportional relationship. is estimated to be less than a predetermined amount, the discharge resistance is stabilized after a predetermined time has elapsed after the start of energization, and as a result, the discharge current is also stabilized.

When the amount of deposits adhering to the charge-part discharge electrode 41a is less than a predetermined amount, as the discharge continues, a dirt layer of the deposits, which is a mixture of water and oil, is formed as shown in FIG. The metal portion of the charge-portion discharge electrode 41a is peeled off to form a hole, or a protrusion is formed on the dirt layer, thereby decreasing the discharge resistance and increasing the discharge current.

[Change in discharge characteristics after energization of the discharge electrode when a large amount of dirt adheres]
FIG. 13 is a diagram showing changes in discharge characteristics after application of a discharge current when there is a large amount of adhered dirt. FIG. 13 shows the discharge current time ( It is a diagram showing a change in energization time). In FIG. 13, the horizontal axis indicates the passage of time in the positive direction, and the vertical axis indicates the magnitude of the discharge current in the positive direction. As shown in FIG. 13, when the amount of deposits adhering to the charge-part discharge electrode 41a is greater than a predetermined amount, the discharge current monotonically decreases with the energization time. , turns monotonically increasing. That is, when the input voltage of the charging section 41 is controlled to be constant, the voltage of the charging section 41 and the discharge current of the charging section 41 are in an inversely proportional relationship. When the amount is greater than a predetermined amount, the discharge resistance increases monotonically after a predetermined time has elapsed after the start of energization, but the discharge resistance decreases monotonically thereafter, so that the discharge current also decreases monotonically, and then monotonically. will increase.

If the amount of deposits adhering to the charge-part discharge electrode 41a is greater than a predetermined amount, as shown in FIG. It takes a long time for holes to form in the thick layer, and moisture evaporates from the dirt layer, which lowers the electrical conductivity and increases the discharge resistance. After that, when the moisture evaporates from the dirt layer and only the oil content remains, sputtering is likely to occur due to the applied voltage. To increase.

[Changes in Charge Amount of Contaminated Discharge Electrode with Elapsed Time]
FIG. 14 is a diagram showing changes in the charge amount of the discharge electrode to which dirt adheres according to the elapsed time. FIG. 14 shows the case where the charge amount of the charging section 41 when no deposit is attached to the charging section discharge electrode 41a is 1, and the amount of deposits attached to the charging section discharge electrode 41a is greater than a predetermined amount. It shows the temporal change of the charge amount ratio (charge amount loss) when it is estimated that As shown in FIG. 14, it can be seen that the charge amount decreases immediately after the start of energization, but recovers as the energization time elapses. In other words, it can be seen that there is a positive correlation between the charge amount of the charge section 41 and the dust collection performance of the charge section 41 .

A discussion based on FIGS. 11-14 yields the results shown in FIGS. 15-17, as described below.

[Change in Discharge Resistance of Discharge Electrode with Elapsed Time]
FIG. 15 is a diagram showing changes in the discharge resistance of the discharge electrode according to elapsed time. FIG. 15 shows the change in the discharge resistance over time with the elapsed time as the horizontal axis, and the amount of deposits (dirt) adhering to the charge-portion discharge electrode 41a is represented by "dirt (much)" and "dirt ( The figure shows the case of "medium)" and "stain (slightly)". As shown in FIG. 15, in the case of "dirty (heavy)", the discharge resistance monotonously increases at the beginning of the elapsed time, but then monotonously decreases at the change point at time t11. In addition, as shown in FIG. 15, in the case of "dirt (medium)", the discharge resistance value is generally lower than in the case of "dirt (heavy)", but the value of "dirt (heavy)" As in the case, the discharge resistance monotonically increases at the beginning of the elapsed time and monotonically decreases at the change point at time t12. In the case of "dirt (heavy)" and "dirt (medium)", since a change point appears, it can be determined that the removal (cleaning) of the deposits adhering to the charge section discharge electrode 41a is required.

On the other hand, as shown in FIG. 15, in the case of "dirt (low)", the discharge resistance monotonically decreases consistently from the beginning of the elapsed time, and no point of change appears. It can be determined that the removal (cleaning) of the attached matter is not necessary.

[Changes in monitor voltage according to elapsed time]
FIG. 16 is a diagram showing changes in monitor voltage according to elapsed time. The change in the voltage (monitor voltage) of the high-voltage power supply 10 for the charging section (monitor voltage) with time (energization time) is as follows. Since it is proportional, it becomes the same as the time (energization time) change of the discharge resistance shown in FIG.

That is, as shown in FIG. 16, in the case of "dirty (heavy)", the monitor voltage monotonously increases at the beginning of the elapsed time, but then monotonously decreases at the change point at time t21. Also, as shown in FIG. 16, in the case of "dirt (medium)", the monitor voltage values are generally lower than those in the case of "dirt (heavy)", but the values of "dirt (heavy)" As in the case, the monitor voltage monotonously increases at the beginning of the elapsed time and monotonically decreases at the change point at time t22. In the case of "dirt (heavy)" and "dirt (medium)", since a change point appears, it can be determined that the removal (cleaning) of the deposits adhering to the charge section discharge electrode 41a is required.

On the other hand, as shown in FIG. 16, in the case of "dirt (low)", the monitor voltage monotonously decreases consistently from the beginning of the elapsed time, and no point of change appears. It can be determined that the removal (cleaning) of the attached matter is not necessary.

[Change in discharge current of discharge electrode according to elapsed time]
FIG. 17 is a diagram showing changes in the discharge current of the discharge electrode according to elapsed time. When the voltage (monitor voltage) V of the high-voltage power supply 10 for the charging section (monitor voltage) is constant, the discharge current of the charging section discharge electrode 41a changes with time (energization time). Since it is inversely proportional to the discharge of the electrode 41a, it becomes as shown in FIG. FIG. 17 shows the temporal change of the discharge current with the elapsed time as the horizontal axis, and the amount of deposits (dirt) adhering to the charge-portion discharge electrode 41a is represented by "dirt (high)" and "dirt ( The figure shows the case of "medium)" and "stain (slightly)". As shown in FIG. 17, in the case of "dirt (heavy)", the discharge current monotonously decreases at the beginning of the elapsed time, but then monotonously increases at the change point at time t31. In addition, as shown in FIG. 17, in the case of "dirt (medium)", the value of the discharge current is generally higher than in the case of "dirt (heavy)", but the value of the "dirt (heavy)" As in the case, the discharge resistance monotonously decreases at the beginning of the elapsed time, and then monotonously increases at the change point at time t32. In the case of "dirt (heavy)" and "dirt (medium)", since a change point appears, it can be determined that the removal (cleaning) of the deposits adhering to the charge section discharge electrode 41a is required.

On the other hand, as shown in FIG. 17, in the case of "dirt (low)", the discharge resistance monotonically increases consistently from the beginning of the elapsed time, and no point of change appears. It can be determined that the removal (cleaning) of the attached matter is not necessary.

That is, as shown in FIGS. 15 to 17, the change point at which the discharge resistance of the charge section discharge electrode 41a or the monitor voltage of the charge section high voltage power supply 10 changes from a monotonous increase to a monotonous decrease, or the change point of the charge section discharge electrode 41a When there is at least one change point among the change points where the discharge current changes from a monotonous decrease to a monotonous increase, it is necessary to remove (clean) the deposits (dirt) adhering to the charge discharge electrode 41a. It can be determined that there is

According to the above embodiments, any one of the discharge voltage value, the discharge current value, and the discharge resistance value of the discharge generated between the discharge electrode and the counter electrode arranged to face the discharge electrode Based on the measured value, whether or not there is a change point where the measured value changes from a monotonous increase to a monotonous decrease, or from a monotonous decrease to a monotonous increase, determines whether the amount of deposits attached to the discharge electrode is large. That is, it determines whether or not it is necessary to remove the deposit adhering to the discharge electrode. Although the discharge resistance is affected by humidity, the embodiment eliminates such influence of the operating environment, so that it is possible to prevent erroneous determination of whether or not to remove deposits adhering to the discharge electrode.

In addition, the change point appears in a shorter time before the measured value stabilizes compared to the conventional technology in which the necessity of the cleaning mode operation process is determined in units of several hours. Therefore, it is possible to determine whether or not the amount of deposits adhering to the discharge electrode is large in a shorter period of time than in the prior art. Therefore, even when the operation of the air purifier 1 is stopped for a short period of time or is operated intermittently, it is possible to determine whether or not the matter attached to the discharge electrode needs to be removed.

The specific names, processes, controls, and information including various data and parameters in the above-described embodiments and illustrations are only examples, and can be changed as appropriate unless otherwise specified. Also, the configuration of each unit or each device in the above-described embodiments may be appropriately distributed or integrated in consideration of the processing load, implementation efficiency, and the like. Further, each process in the above-described embodiments may be executed by appropriately changing the order of the processes in consideration of the processing load, implementation efficiency, and the like.

The broader aspects of the above-described embodiments are not limited to the specific details and representative embodiments shown and described above. Accordingly, various changes may be made without departing from the general inventive concept or scope as defined by the appended claims and equivalents thereof.

1 air cleaner 2 suction port 3 prefilter 4 electric dust collector 5 deodorizing filter 6 fan 7 fan motor 8 outlet 9 control board 10 high voltage power supply 10a for charging section input section 10b boost section 10c output section 10d voltage detection section 10e current Detection unit 11 High voltage power supply for dust collection unit 12 Operation display board 13 Dust sensor 14 Power supply 41 Charging unit 41a Charging unit discharge electrode 41b Charging unit counter electrode 42 Dust collection unit 42a Dust collection unit collection electrode 42b Dust collection unit high voltage electrode 91a Charging Unit switch 92 Dust collection unit switch 93 Control unit 93a Discharge resistance calculation unit 93b Change point determination unit 93c Operation control unit 93d Storage unit 93e Humidity sensor 93f Notification unit 94 Power supply unit

Claims (4)

a discharge electrode;
a counter electrode arranged to face the discharge electrode;
a voltage applying unit that applies a voltage to the discharge electrode;
A discharge voltage measurement unit for measuring a discharge voltage value between the discharge electrode and the counter electrode, a discharge current measurement unit for measuring a discharge current value between the discharge electrode and the counter electrode, and the discharge electrode and the counter electrode a measurement unit including at least one discharge resistance measurement unit that measures the discharge resistance value between the electrodes;
a storage unit that stores a plurality of measured values measured by the measurement unit at time intervals of minutes ;
In the plurality of measured values stored in the storage unit, the measured value changes from a monotonous increase in which the measured value continuously increases a plurality of times to a monotonous decrease in which the measured value decreases continuously a plurality of times, or the measured value changes continuously a plurality of times. Determining the presence or absence of a change point where the measured value changes from a monotonous decrease in which the measured value decreases continuously to a monotonous increase in which the measured value increases continuously a plurality of times, and when it is determined to have the change point, attached to the discharge electrode a determination unit that determines that the amount of adhering matter is large;
A charging device comprising: A timing unit that measures the elapsed time from the start of energization to the voltage application unit to the occurrence of the change point,
2. The charging device according to claim 1, wherein the determination unit determines the amount of deposits attached to the discharge electrode based on the elapsed time measured by the time measurement unit. A first removal unit for removing deposits adhering to the discharge electrode,
3. The charging device according to claim 2, wherein the first removal section performs a first removal operation of generating sputtering by applying a high voltage to the discharge electrode. When the elapsed time is within the range of the predetermined threshold value, the first removal operation is performed by the first removal unit, and when the elapsed time is out of the range of the predetermined threshold value, the discharge is performed. 4. The apparatus according to claim 3, wherein a notification unit notifies that the electrode needs to be cleaned, or a second removal operation is performed by a second removal unit for removing deposits adhering to the discharge electrode. Charging device as described.

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