JP2000074451A - Choking detector for filter of air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect choking of air filter without requiring any extra apparatus by utilizing temperature variation of an indoor side heat exchanger due to variation in the volume of air passing through the air filter. SOLUTION: The choking detector of air filter comprises a temperature sensor 7 for detecting the duct temperature of an indoor side heat exchanger, an operating time integrating section 23, an operation control section 22 for continuing operation while changing the rotation mode of an indoor side fan 31 for a predetermined time every time when a predetermined operating time is integrated at the integrating section 23, a comparing section 21 for monitoring and determining the duct temperature variation width of the indoor side heat exchanger detected by the temperature sensor 7 for the predetermined time when the indoor side fan 31 is operating in changed rotation mode and comparing the variation width with a preset reference width, and a section 26 for alarming the replacing time of air filter if the duct temperature variation width is smaller than the reference width.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant compressor, an indoor heat exchanger having an air filter disposed in front thereof, an indoor fan, an outdoor heat exchanger, an outdoor fan, and an indoor heat exchanger. The present invention relates to an air conditioner having a refrigeration cycle formed by a decompressor inserted between an outdoor heat exchanger and a four-way valve for switching a connection between a refrigerant compressor and an indoor heat exchanger or an outdoor heat exchanger. More specifically, the present invention relates to an air filter clogging detection device for an air conditioner that detects clogging of an air filter by utilizing the fact that the temperature of an indoor heat exchanger changes depending on the amount of air passing through an air filter.

[0002]

2. Description of the Related Art In a conventional air conditioner, a four-way valve, an outdoor heat exchanger, a decompressor, an indoor heat exchanger, and a four-way valve are switched by switching a four-way valve during a cooling operation. In the heating operation, the refrigerant compressed by the compressor is returned to the compressor via the four-way valve, the indoor heat exchanger, the decompressor, the outdoor heat exchanger, and the four-way valve. Circulating.

In such a cooling operation or a heating operation, indoor air is sucked through an air filter disposed in front of the indoor heat exchanger, and heat exchange with refrigerant is performed by the indoor heat exchanger. Cold air is blown into the room during cooling, and warm air is blown into the room during heating. That is, when the room air is passed through the air filter, dust and dirt contained in the air adhere to the air filter, causing clogging. Therefore, it is necessary to clean or replace the air filter at an appropriate timing.

Therefore, various devices for detecting clogging of the air filter have been conventionally proposed. For example, the operation time of the air conditioner is integrated, and when the integrated time exceeds a certain time (for example, 100 hours), it is determined that it is time to clean or replace the air filter (for example,
Japanese Patent Application Laid-Open No. 57-67742), a device that integrates the air volume during operation of an air conditioner, and determines that it is time to clean or replace the air filter when the integrated air volume exceeds a certain amount. There is.

[0005] However, none of these methods detect the actual clogging of the air filter, and cleans or replaces the air filter based on the prediction that the air filter is likely to be clogged. It is. For this reason, depending on the operating environment of the air conditioner, clogging may not yet occur, or clogging may have already occurred and the replacement time has passed.

Therefore, an apparatus for directly detecting clogging of an air filter has been proposed (for example, see Japanese Patent Application Laid-Open No. 58-158434). This device detects the pressure in the suction side wind tunnel located between the air filter and the indoor side fan in the indoor unit of the air conditioner, and moves when the pressure becomes lower than a predetermined pressure. The other end of the light-entering optical fiber, one end of which is provided at a position to receive outdoor light, and the other end of the display-side optical fiber, which is provided by exposing one end to the surface of the indoor unit, are provided. They are arranged to face each other via an operating body. And
The actuating body is located between the other ends of the two optical fibers when the pressure in the suction-side wind tunnel is equal to or higher than a predetermined pressure (that is, shuts off both optical fibers). The optical fibers are separated from each other (that is, both optical fibers are conducted) (this is referred to as conventional technology 1).

[0007] An apparatus has also been proposed which detects not only the clogging of the air filter but also the contamination of the indoor heat exchanger (see Japanese Patent Application Laid-Open No. 5-264136). Accumulates the operation time of the air conditioner, and when the accumulated time exceeds a certain time, determines that it is time to clean or replace the air filter. Alternatively, a sound generated when air passes through the air filter after a certain period of time is detected by the sound detection means, and when the level exceeds a certain level, it is determined that it is time to clean or replace the air filter. (This is referred to as conventional technology 2).

[0008]

However, the prior art 1 utilizes the fact that the air flow is reduced due to the clogging of the air filter.
In order to utilize the decrease in the air volume, it is necessary to arrange an operating body in the suction-side wind tunnel and arrange an optical fiber so as to sandwich the operating body. In other words, it is necessary to provide a dedicated device for detecting clogging of the air filter,
Accordingly, there have been problems that the apparatus becomes complicated, the number of parts increases, and the manufacturing cost increases.

The prior art 2 is based on the principle that the operation time of the air conditioner is integrated in principle.
It has the problems as described above, and it also detects a sound generated when air passes through the air filter, but also has an extra device for detecting the sound, that is, an air conditioner. An extra device that is not directly related to the operation is required, and the device becomes complicated, the number of parts increases, and the manufacturing cost increases. The present invention has been conceived to solve such a problem, and its purpose is to utilize the fact that the temperature of the indoor heat exchanger changes depending on the amount of air passing through an air filter, thereby providing a means other than the refrigeration cycle. An object of the present invention is to provide an air filter clogging detection device of an air conditioner which can detect clogging of an air filter without using an extra device.

[0010]

According to a first aspect of the present invention, there is provided an air conditioner air filter clogging detection apparatus, comprising: a refrigerant compressor; A heat exchanger, an indoor fan,
An outdoor heat exchanger, an outdoor fan, and a pressure reducer interposed between the indoor heat exchanger and the outdoor heat exchanger,
In an air conditioner provided with a refrigeration cycle formed by the refrigerant compressor and a four-way valve for switching the connection between the indoor heat exchanger or the outdoor heat exchanger, a temperature at which a conduit temperature of the indoor heat exchanger is detected. Detecting means, operating time integrating means for integrating the operating time of heating or cooling, and after starting the heating operation or cooling operation, every time a predetermined operating time is integrated by the operating time integrating means, the room is maintained for a certain period of time. A rotation mode changing unit that changes the rotation mode of the inside fan from the previous mode and continues the operation, and a temperature detection unit that detects the rotation mode of the indoor fan for a certain period of time while operating while changing the rotation mode. Comparing means for monitoring a temperature change in the conduit temperature of the indoor side heat exchanger to determine a change width thereof, and comparing the obtained change width with a reference width set in advance therein; Based on the comparison result of the means, when the change width of the conduit temperature is less than the reference width, a structure in which a warning means for warning the replacement time of the air filter.

According to a second aspect of the present invention, in the air conditioner air filter clogging detecting apparatus according to the first aspect, the reference width is determined by a rotation mode of the indoor fan up to that. A plurality of types are set in accordance with a combination of the rotation mode and another rotation mode that is changed for a certain period of time, and the comparing means sets a plurality of types of reference widths based on the rotation mode of the indoor fan up to that time. A corresponding reference width is selected from among them and set inside.

According to a third aspect of the present invention, there is provided an air filter clogging detection device for an air conditioner according to the first or second aspect, wherein the change width of the conduit temperature determined by the comparing means is the same as that of the first aspect. If the difference is larger than the reference width, a configuration is provided that includes a time determination unit that determines the next predetermined operation time to be integrated by the operation time integration unit based on the difference between the change width and the reference width. The air filter clogging detection device for an air conditioner according to claim 4 of the present invention is the air conditioner clog detection device according to claim 3, wherein the time determination means is configured such that the larger the difference between the change width and the reference width is, The next predetermined operation time integrated by the operation time integration means is determined to be longer, and as the difference between the change width and the reference width is smaller,
The determination is made so as to shorten the next predetermined operation time accumulated by the operation time accumulation means.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram (refrigeration cycle) of an air conditioner provided with an air filter clogging detection device of the present invention. In the figure, a discharge port 11 and a suction port 12 of a compressor 1 are connected via a four-way valve 2 to one connection port of an indoor heat exchanger 3 having an indoor fan 31,
The other connection port of the indoor heat exchanger 3 and the other connection port of the outdoor heat exchanger 5 are connected to one connection port of the outdoor heat exchanger 5 having the outdoor fan 51.
Connected through. The indoor heat exchanger 3 has a temperature sensor 7 for detecting the temperature (substantially the conduit temperature) of the refrigerant flowing in a conduit (not shown) provided therein.
Is attached.

During the heating operation, the four-way valve 2 is switched so that the discharge port 11 of the compressor 1 and the indoor heat exchanger 3 are switched.
Is connected to the suction port 12 of the compressor 1 and one of the connection ports of the outdoor heat exchanger 5, the high-temperature refrigerant compressed by the compressor 1 is shown in FIG. It heats the room by flowing like the arrow shown by the solid line. That is, the high-temperature refrigerant compressed by the compressor 1 is supplied to the indoor heat exchanger 3 through the four-way valve 2, where the indoor fan 31 forcibly exchanges heat to heat the indoor. Indoor heat exchanger 3
The refrigerant condensed after the heat exchange is decompressed by the decompressor 4 and supplied to the outdoor heat exchanger 5 where the heat is forcibly exchanged by the outdoor fan 51 and the surface temperature of the outdoor heat exchanger 5 is reduced. Lower. The refrigerant vaporized after the end of heat exchange by the outdoor heat exchanger 5 is circulated to the compressor 1 again through the four-way valve 2.

On the other hand, at the time of cooling operation, by switching the four-way valve 2, the discharge port 11 of the compressor 1 and one connection port of the outdoor heat exchanger 5 are connected, and the suction port 12 of the compressor 1 and the indoor heat exchanger are connected. Since one of the connection ports of the exchanger 3 is connected, the high-temperature refrigerant compressed by the compressor 1 flows as indicated by broken arrows in the drawing to cool the room. FIG. 2 is a sectional view of the indoor unit of such an air conditioner as viewed from the side.

The indoor unit has a suction port 32 at the front.
A case body 30 provided with an air outlet 33 below the suction port 32 (below the front surface); an openable front panel 34 attached to the suction port 32 of the case body 30; An indoor heat exchanger 3 provided in the case main body 30 facing the suction port 32 of the main body 30, and an air outlet 33 from the suction port 32 via the indoor heat exchanger 3.
A cross-flow indoor fan 31 is provided in the vicinity of the back side of the air outlet 33 to circulate the air to the inside. Top plate 35 and front panel 34 of case body 30
A front grille 36 and a front grille 37 for sucking air are respectively provided on the front side of the air conditioner. An air filter 38 is provided between the front panel 34 and the indoor heat exchanger 3.
Is provided.

During the automatic operation (heating operation or cooling operation) of such an air conditioner, the indoor air is supplied to the front panel by the operation of the indoor fan 31 as shown by the solid arrow in FIG. 34 front grille 37 and case body 3
The air flows into the case main body 30 from the upper surface grill 36, passes through the air filter 38, and is heat-exchanged in the outdoor heat exchanger 3, and then passes through the indoor fan 31 and the outlet 33.
From the room.

FIG. 3 is a block diagram showing the electrical configuration of the air filter clogging detecting device according to the present invention, and corresponds to claims 1 and 2. The output of the temperature sensor 7 for detecting the temperature of the conduit of the indoor side heat exchanger 3 monitors the temperature change of the conduit temperature to determine the variation width, and compares the determined variation width with a reference width preset inside. 1 and an operation control unit 22 for controlling the refrigeration cycle shown in FIG. 1, and the comparison unit 21 and the operation control unit 22 are bidirectionally connected.

The operation control unit 22 has a bidirectionally connected operation time accumulation unit 23 for accumulating the operation time of heating or cooling and a timer unit 24 for measuring an arbitrary time period. The output of the input unit 25 provided with a switch (not shown) is led. Further, the operation control unit 22 is connected to a warning unit 26 for notifying the user of the time for cleaning or replacing the air filter 38. The operation time integrating unit 23 outputs an integration end signal to the operation control unit 22 after integrating the preset operation time (for example, 50 hours). Operation time integration unit 23
Is not reset only by stopping the operation (heating operation, cooling operation, dehumidifying operation, defrosting operation, etc.) of the air conditioner, but is reset for the first time by a reset signal from the operation control unit 22 described later. It has become.

The timer section 24 measures an arbitrary time set by the operation control section 22. The warning unit 26 includes, for example, a buzzer, an LED, and the like. The warning unit 26 sounds a buzzer based on a warning signal from the operation control unit 22, turns on or blinks an LED, or the like, and provides a user with an air filter 38. The time of cleaning or replacement is notified.

The operation control unit 22 operates according to a program for executing various operation modes (heating operation mode, cooling operation mode, air filter 38 clogging inspection operation mode described later, etc.) stored in an internal memory (not shown) according to FIG. Is a block for controlling the refrigeration cycle shown in FIG. The operation control unit 22 changes the rotation mode of the indoor-side fan 31 for a predetermined time (for example, three minutes) every time a predetermined time (50 hours or the like) accumulated by the operation time accumulation unit 23 elapses. (For example, by changing to “M (Mid)”) from the mode (for example, “H (High)”),
Execute the clogging inspection operation mode to continue the operation. That is, the rotation mode changing unit according to the first aspect is realized by the operation control unit 22 in the present embodiment.
When the clogging inspection operation mode is executed, the operation control unit 22 outputs a reset signal to the operation time integration unit 23.

The comparison unit 21 changes the temperature of the conduit temperature of the indoor heat exchanger 3 detected by the temperature sensor 7 during a certain time (3 minutes) during which the indoor fan 31 is operated while changing the rotation mode. Is monitored to determine a variation width ΔT, and the determined variation width ΔT and a reference width Ts set in advance are calculated.
(This will be described later). If the change width ΔT is smaller than the reference width Ts, it is determined that the air filter 38 is clogged to a state requiring cleaning or replacement, and an instruction signal for instructing cleaning or replacement of the air filter 38 is provided. Is output to the operation control unit 22.

That is, in the present invention, the indoor fan 31
Is changed from the previous mode to another mode and the operation is continued, and the clogging state of the air filter 38 is detected by obtaining the change width ΔT of the conduit temperature of the indoor heat exchanger 3. The reason why the clogged state of the air filter 38 can be detected by this is described below.

As described above, the temperature of the conduit of the indoor heat exchanger 3 is affected by the amount of air passing through the air filter 38. For example, in the case of the heating operation, the pipe temperature of the indoor heat exchanger 3 becomes lower as the amount of air passing through the air filter 38 is larger, so that more heat is taken away by the air. Is high because there is little. In the case of cooling operation, the opposite is true.
The temperature of the conduit of the indoor heat exchanger 3 increases as the amount of air passing through the air filter 38 increases, and decreases as the amount of air passing through the air filter 38 decreases.

Hereinafter, the heating operation will be described as an example.
I will tell. For example, the rotation of the indoor fan 31 is set to the “H” mode.
100% transmittance (when completely clogged)
(No state) passing through the air filter 38 for 1 minute
The amount of air (air volume) is 10m^ThreeIn this state, the indoor side fan
Indoor heat exchanger 3 when the rotation of the fan 31 is in the "H" mode.
Assuming that the conduit temperature is 45 ° C and the indoor temperature is 25 ° C,
The outlet temperature of the port 33 is, for example, 5 ° C. from the conduit temperature (45 ° C.).
10m because it is about 40 ℃^Three× 15 (= 40−
25) C = 150m^Three・ The amount of heat equivalent to ° C is the indoor heat
It will be robbed from exchange 3 in one minute. Meanwhile, indoors
When the rotation of the side fan 31 is in the “M” mode, the transmittance 1
Of air passing through a 00% air filter 38 in one minute.
7m (air volume)^ThreeThen, the rotation of the indoor fan 31
When the mode is switched from "H" to "M", 7m^Three×
15 (= 40-25) ° C = 105m^Three・ Heat equivalent to ° C
Amount will be taken from the indoor heat exchanger 3 in one minute.
You. That is, if the air filter 38 has a transmittance of 100%
The rotation mode of the indoor fan 31 from "H"
When switched to "M", it is taken from indoor heat exchanger 3
The amount of heat equivalent is 150m ^Three・ 105m from ℃^Three・ Changes to ° C
And the amount of change is 45m^Three・ It becomes ° C. That is,
45m more than before^Three・ Small amount of heat removed by ℃
Because the temperature of the pipe of the indoor heat exchanger 3 is
It will rise by a considerable amount (for example, by 4 ° C.).

Next, when the rotation of the indoor side fan 31 is in the "H" mode, the amount of air passing through the air filter 38 having a transmittance of 50% (half-clogged) in one minute (air volume). Is 5 m ^{3. In} this state, the indoor fan 31
Assuming that the indoor temperature of the indoor heat exchanger 3 is 45 ° C. and the indoor temperature is 25 ° C. when the rotation of the air conditioner is in the “H” mode, the outlet 33
Is about 5 ° C. lower than the pipe temperature (45 ° C.), for example, 40 ° C., so that 5 m ³ × 15 (= 40−25) ° C.
= 75 m ³ · ° C. is taken from the indoor heat exchanger 3 in one minute. On the other hand, the indoor fan 3
When the rotation of the first fan 31 is in the “M” mode, the amount of air passing through the air filter 38 having a transmittance of 50% in one minute (air volume) is 3.5 m ^3. 3.5m ³ × 1 when switching from “H” to “M”
The amount of heat corresponding to 5 (= 40-25) ° C. = 52.5 m ³ · ° C. is taken from the indoor heat exchanger 3 in one minute. That is, when the air filter 38 has a transmittance of 50%, the rotation mode of the indoor fan 31 is changed from “H” to “M”.
, The amount of heat taken from the indoor heat exchanger 3 changes from 75 m ³ · ° C. to 52.5 m ³ · ° C.,
The change amount is 22.5 m ³ · ° C. That is, since the amount of heat equivalent to 22.5 m ³ · ° C. is reduced, the temperature of the conduit of the indoor heat exchanger 3 rises (for example, by 2 ° C.).

As described above, when the rotation mode of the indoor fan 31 is switched from, for example, “H” to “M”, the change in the conduit temperature of the indoor heat exchanger 3 due to the transmittance (clogged state) of the air filter 38. The width (rising width) will be different. In the case of the cooling operation, the theory is exactly the same as in the case of the heating operation, and the change width is not a rise but a decrease. For such a reason, by changing the rotation mode of the indoor fan 31 from the previous mode to another mode and continuing the operation, the variation width ΔT of the conduit temperature of the indoor heat exchanger 3 is obtained, The clogged state of the air filter 38 can be detected.

FIG. 4 is a table showing the relationship between the combination of the modes to be changed and the reference width Ts at that time, which is stored in an internal memory (not shown) of the comparison unit 21 in advance. In the present embodiment, the rotation modes of the indoor fan 31 are “H (High)”, “M (Mid)”, and “L”.
(Low) "and" LL (Low-Low) ". Here, the “LL” mode is a mode that cannot be operated on the user side, and is a mode used by an inspection worker at the time of inspection or the like. Also, a reference width Ts, which is a reference for comparing the cleaning or replacement time of the air filter 38,
In this embodiment, the transmittance of the air filter 38 is 5
In the state of 0%, the change width of the pipe temperature of the indoor heat exchanger 3 when the operation is continued by changing the rotation mode of the indoor fan 31 is shown. Here, as combinations of the change modes, there are three types of combinations that change only one stage from “H” to “M”, “M” to “L”, “L” to “LL”, and “H” to “H”. L ”,“ M ”to“ L ”
A total of six types of combinations are prepared, two types of combinations that change two steps of “L” and one type of combinations that change three steps of “H” to “LL”. In the present embodiment, the reference width Ts corresponding to each combination is
"1 degree change" is set to "2 degrees Celsius", 2 step change is set to "4 degrees Celsius", and 3 step change is set to "6 degrees Celsius". It is determined in advance by experiments and the like.

In the clogging inspection operation mode, it is not necessary to use all of these six combinations. For example, even if the clogging inspection operation mode is executed using only three types of combinations that are changed by only one stage. Alternatively, the clogging inspection operation mode may be executed using only two types of combinations that are changed in two stages. However, when only two types of combinations that change in two stages are used, when the rotation mode of the indoor-side fan 31 during the heating operation before entering the clogging inspection operation mode is the “L” mode, the table shown in FIG. Has no mode to be changed, but in this case, by changing from "L" to "H", the data in the table shown in FIG. 4 can be used.

As described above, in this embodiment, in addition to the three types in which only one stage is changed, a case in which two stages are changed and a case in which three stages are changed are prepared. The larger the change width of the rotation mode to be performed, the more clearly the temperature change due to the influence of the clogged state of the air filter 38 appears. May be used. It should be noted that which change mode is to be used is set internally in advance.

Next, a clogging detecting operation of the air conditioner provided with the air filter clogging detecting device having the above configuration will be described with reference to a flowchart shown in FIG. However, here, the heating operation will be described as an example. When a start switch (not shown) of the heating operation is operated, an operation signal is input from the input unit 25 to the operation control unit 22. The operation control unit 22 controls the refrigeration cycle based on the operation signal and starts the heating operation (step S1). At the same time, the operation control unit 22 causes the operation time accumulation unit 23 to start accumulating the operation time (step S2). The integration at this time is performed by adding the integrated value of the previous operation, if any, to the integrated value.

When the heating operation is started, the temperature sensor 7 detects the temperature of the conduit of the indoor heat exchanger 3 as needed (step S3), and compares the detected temperature with the comparison unit 21 and the operation control unit 2.
2 and output. The operation control unit 22 has conventionally performed various controls based on the detected temperature. Further, the comparison unit 21 monitors the conduit temperature detected by the temperature sensor 7 as needed. After the start of the heating operation, when 50 hours are accumulated by the operation time accumulation unit 23 (step S4), the operation time accumulation unit 23 outputs an accumulation end signal to the operation control unit 22. The operation control unit 22 outputs a start instruction signal to the comparison unit 21 based on the integration end signal, and executes the clogging inspection operation mode (Step S5).

That is, if the rotation mode of the indoor fan 31 at that time is, for example, the “H” mode, the operation control unit 22 changes the “H” mode to, for example, the “M” mode, which is one step lower. Then, the heating operation is continued (step S6). At the same time, the operation control unit 22 causes the timer unit 24 to start measuring a fixed time, for example, three minutes (step S7). The operation control unit 22
Outputs the rotation mode data of the indoor fan 31 at that time to the comparison unit 21. The comparison unit 21 selects a reference width Ts corresponding to the combination of the modes to be changed from the table shown in FIG. 4 stored in the internal memory based on the rotation mode data from the operation control unit 22,
Set internally. In this case, 2 ° C. corresponding to the change mode from “H” to “M” is selected as the reference width Ts and set internally (step S8).

When a measurement signal indicating that three minutes have been measured is input from the timer section 24 (step S).
9), the operation control unit 22 outputs an end instruction signal to the comparison unit 21 based on the measurement signal (step S1).
0). The comparison unit 21 detects the indoor heat exchanger 3 detected by the temperature sensor 7 for three minutes from when the start instruction signal is input from the operation control unit 22 to when the end instruction signal is input.
(Step S11), and compares the obtained change width ΔT with a reference width Ts (2 ° C.) set inside, and outputs the comparison result. (Step S12).

More specifically, steps S11 and S12 will be described. Based on the start instruction signal from the operation control unit 22, the comparison unit 21 detects the temperature of the conduit of the indoor heat exchanger 3 detected by the temperature sensor 7 at that time. (For example, T1)
Then, based on the next termination instruction signal, the temperature of the conduit (for example, T2) of the indoor heat exchanger 3 detected by the temperature sensor 7 at that time is captured. And ΔT = T1
The calculation of -T2 is performed to obtain the change width ΔT of the conduit temperature (step S11). Then, the obtained value ΔT is compared with a reference width Ts (2 ° C.) set inside (step S12). If ΔT ≧ Ts, it is determined that the air filter 38 is not clogged. Since it is possible, a continuation instruction signal for instructing the continuation of the heating operation is output to the operation control unit 22 (step S13). On the other hand, if ΔT <Ts (No in step S12), it can be determined that the air filter 38 is clogged.
An instruction signal for instructing cleaning or replacement of the air filter 38 is output to the operation control unit 22 (step S15).

When the operation control unit 22 receives the continuation instruction signal from the comparison unit 21 in step S13, the operation control unit 22 changes the rotation mode of the indoor fan 31 from the "M" mode to the original "H" mode, and performs the heating operation. While continuing (step S14), the process returns to step S2, and the operation time integration unit 2
3 is started. The integration at this time is
Start from zero.

On the other hand, as a result of comparison in step S12, Δ
If T <Ts, the comparison unit 21 sends the operation control unit 2
Since an instruction signal for instructing cleaning or replacement of the air filter 38 is output to the second control unit 2 (step S15), the operation control unit 22 outputs a warning signal to the warning unit 26 (step S15).
16). Based on the warning signal, the warning unit 26 sounds, for example, a buzzer, or turns on or blinks an LED or the like, to notify the user that it is time to clean or replace the air filter 38 (step S17). After that, the operation control unit 22 changes the rotation mode of the indoor fan 31 from the “M” mode to the original “H” mode, continues the heating operation (step S14), and returns to step S2. The operation time accumulation unit 23 is started to accumulate the operation time.

FIG. 6 is a block diagram showing another embodiment of the air filter clogging detecting device according to the present invention, and corresponds to claims 3 and 4. That is, the output of the comparing unit 21 is guided to the time determining unit 27, and the time determining unit 25
Is guided to the operation control unit 22.
The other configuration is completely the same as that shown in FIG. 3, and thus the same reference numerals are given here.

The time determining unit 27 determines the next predetermined operating time to be integrated by the operating time integrating unit 23, based on the change width ΔT of the conduit temperature determined by the comparing unit 21, and determines the determined operating time data. Is output to the operation control unit 22. Here, the predetermined operation time is set to an arbitrary time between 25 hours and 100 hours in the present embodiment. For example, assuming that the reference width Ts is the reference width (= 2 ° C.) when changing by one step shown in FIG.
Is between 2 ° C. and 3 ° C. (ie, ΔT−Ts (2 ° C.) =
When the air filter 38 is close to the reference width Ts (2 ° C.) at which it is determined that the air filter 38 is clogged, the predetermined operation time is set to 25 hours shorter than the previous time. Further, ΔT is between 3 ° C. and 4 ° C. (that is, ΔT−
Ts (2 ° C.) = 1 to 2 ° C.), the reference width Ts
(= 2 ° C.) (it can be determined that the air filter 38 is hardly clogged). In this case, the predetermined operation time is set to 50 hours, the same as the previous time. Further, ΔT is 4 ° C. or more (that is, (ΔT−Ts)
> 2 ° C.), it is far away from the reference width Ts (= 2 ° C.) (it can be determined that the air filter 38 is not clogged at all). Set to 100 hours. Since the relationship between the value of ΔT and the time varies depending on the performance of the air conditioner and the like, the optimal relationship is determined in advance by experiments and the like.

The operation control section 22 sets the next predetermined operation time to be integrated by the operation time integration section 23 based on the operation time data. Next, a clogging detection operation of the air conditioner including the air filter clogging detection device having the above configuration will be described with reference to a flowchart shown in FIG. When a start switch (not shown) of the heating operation is operated, the operation signal is transmitted from the input unit 25 to the operation control unit 22.
Is input to The operation control unit 22 controls the refrigeration cycle based on the operation signal and starts the heating operation (Step S21). At the same time, the operation control unit 22 causes the operation time accumulation unit 23 to start accumulating the operation time (step S22). The integration at this time is performed by adding the integrated value of the previous operation, if any, to the integrated value.

When the heating operation is started, the temperature sensor 7 detects the temperature of the conduit of the indoor heat exchanger 3 as needed (step S23), and outputs the detected temperature to the comparison unit 21 and the operation control unit 22. . The operation control unit 22 has conventionally performed various controls based on the detected temperature. Further, the comparison unit 21 monitors the conduit temperature detected by the temperature sensor 7 as needed. After the heating operation is started, when 50 hours are accumulated by the operation time accumulation unit 23 (step S24), the operation time accumulation unit 23 outputs an accumulation end signal to the operation control unit 22. The operation control unit 22 outputs a start instruction signal to the comparison unit 21 based on the integration end signal, and executes the clogging inspection operation mode (Step S25).

That is, if the rotation mode of the indoor fan 31 at that time is, for example, the "H" mode, the operation control unit 22 changes the "H" mode to the "M" mode, for example, one step lower. Then, the heating operation is continued (step S26). At the same time, the operation control unit 22 causes the timer unit 24 to start measuring a fixed time, for example, three minutes (step S27). The operation control unit 2
2 outputs the rotation mode data of the indoor fan 31 at that time to the comparison unit 21. The comparison unit 21 selects a reference width Ts corresponding to the combination of the modes to be changed from the table shown in FIG. 4 stored in the internal memory based on the rotation mode data from the operation control unit 22, and Set to. In this case, 2 ° C. corresponding to the change mode from “H” to “M” is selected as the reference width Ts and set internally (step S28).

When a measurement signal indicating that three minutes have been measured is input from the timer section 24 (step S2).
9), the operation control unit 22 outputs an end instruction signal to the comparison unit 21 based on the measurement signal (Step S3).
0). Based on the start instruction signal from the operation control unit 22, the comparison unit 21 captures the conduit temperature (for example, T1) of the indoor heat exchanger 3 detected by the temperature sensor 7 at that time, and outputs the same to the next end instruction signal. Then, the temperature of the conduit of the indoor heat exchanger 3 (for example, T2) detected by the temperature sensor 7 at that time is taken in. Then, ΔT = T1-T
By performing the calculation of 2, the change width ΔT of the conduit temperature is obtained (step S31). Then, the obtained value ΔT is compared with a reference width Ts (2 ° C.) set inside (step S32). If ΔT ≧ Ts, it is determined that the air filter 38 is not clogged. Since it is possible, a continuation instruction signal for instructing the continuation of the heating operation to the operation control unit 22 is output (step S33). On the other hand, if ΔT <Ts (No in step S32), it can be determined that the air filter 38 is clogged, and thus the instruction signal for instructing the operation control unit 22 to clean or replace the air filter 38. Is output (step S38).

Upon receiving the continuation instruction signal from the comparing section 21 in step S33, the operation control section 22 changes the rotation mode of the indoor side fan 31 from the "M" mode to the original "H" mode, and performs the heating operation. Continue (Step S3
4). At this time, the time determining unit 27 determines the next predetermined operating time to be integrated by the operating time integrating unit 23 based on the value ΔT input from the comparing unit 21 and transmits the determined operating time data to the operation control. Output to the unit 22. (Step S35). That is, as described above, ΔT is 2 ° C.
If it is between 3 ° C. and 3 ° C., the next predetermined operating time is determined to be 25 hours shorter than the previous time, and if ΔT is between 3 ° C. and 4 ° C., the next predetermined operating time is Same as 50
When the time is determined and ΔT is 4 ° C. or more, the next predetermined operation time is determined to be a maximum of 100 hours, and the operation time data is output.

The operation control unit 22 outputs a reset signal to the operation time accumulation unit 23 to reset the integrated value of the operation time accumulation unit 23, and then performs the next predetermined operation time (for example, 25) based on the operation time data. ) Is started (step S36). Then, after the start of the heating operation, when the predetermined operation time (25 hours) is accumulated in the operation time accumulation unit 23 (step S37), the operation control unit 22
Repeats the processing from step S25 to step S37 again. That is, the presence or absence of clogging of the air filter 38 is determined based on the change width of the conduit temperature of the indoor heat exchanger 3 when the rotation mode of the indoor fan 31 is changed (steps S25 to S32), and the determination result , A process of continuing the heating operation and a process of determining the next predetermined operation time (steps S33 to S36).

On the other hand, as a result of the comparison in step S32, ΔΔ
If T <Ts (No in step S32), an instruction signal for instructing cleaning or replacement of the air filter 38 is output from the comparison unit 21 to the operation control unit 22 (step S38), and thus the operation control is performed. The unit 22 outputs a warning signal to the warning unit 26 (Step S39). Based on the warning signal, the warning unit 26 sounds a buzzer, turns on or blinks an LED, or the like to notify the user that it is time to clean or replace the air filter 38 (step S40). Thereafter, the operation control unit 2
2 changes the rotation mode of the indoor side fan 31 from the “M” mode to the original “H” mode, continues the heating operation (step S41), and returns to step S22.
The operation time accumulation unit 23 is started to accumulate the operation time.

In the above embodiment, the time determining unit 2
As a method for determining the predetermined time in 5, ΔT is 2 ° C. to 3 ° C.
Between 25 ° C., 50 hours when ΔT is between 3 ° C. and 4 ° C., and 100 hours when ΔT is 4 ° C. or more. Although it is determined by time, it is not limited to these three types. For example, it is possible to finely divide the temperature into five types for each 0.5 ° C. Further, in the above embodiment, the clogging detection operation of the air filter 38 is described by taking the heating operation as an example, but the operation is exactly the same during the cooling operation. However, the table shown in FIG. 4 needs to be set corresponding to the cooling operation, but can theoretically be set to the reference width Ts which is almost the same as that of the heating operation.

[0048]

The air filter clogging detecting device for an air conditioner according to the present invention comprises a temperature detecting means for detecting a pipe temperature of an indoor heat exchanger, an operating time integrating means for integrating operating time of heating or cooling, After the start of heating operation or cooling operation,
Each time the predetermined operation time is accumulated by the operation time accumulation means, the rotation mode changing means for changing the rotation mode of the indoor fan from the previous mode for a predetermined time and continuing the operation, During a certain time during which the operation is performed while changing the rotation mode, the temperature change of the pipe temperature of the indoor heat exchanger detected by the temperature detecting means is monitored to determine the change width. Comparing means for comparing with the reference width set in the above, based on the comparison result by this comparing means, when the width of change of the conduit temperature is smaller than the reference width, a warning means for warning the air filter replacement time. Thus, clogging of the air filter can be reliably detected without using an extra device other than the refrigeration cycle.

Further, the air filter clogging detection device for an air conditioner according to the present invention is characterized in that the reference width is set between the previous rotation mode of the indoor fan and another rotation mode for changing the rotation mode for a predetermined time. A plurality of types are set in accordance with the combination, and the comparing means selects a corresponding reference width from among the plurality of types of reference widths based on the rotation mode of the indoor fan so far and sets the selected reference width internally. For example,
3 types to change the rotation mode by 1 step, 2 steps to change the rotation mode 2
If a total of six types, one of which is changed in three steps, are set, a change width of the rotation mode to be changed in the clogging inspection operation mode can be arbitrarily set, so that more accurate clogging inspection can be performed.

In the air filter clogging detection device for an air conditioner according to the present invention, when the variation width of the conduit temperature is larger than the reference width, the operating time integrating means is provided based on the difference between the variation width and the reference width. Time determining means for determining the next predetermined operation time to be integrated by the operation time integrating means. The time determining means determines the next predetermined operation integrated by the operating time integrating means as the difference between the change width and the reference width increases. The time is determined to be longer, and as the difference between the change width and the reference width is smaller, the next predetermined operation time integrated by the operation time integration means is determined to be shorter. It is possible to warn of clogging at an optimum timing according to the use situation, that is, a warning of cleaning or replacement timing.

[Brief description of the drawings]

FIG. 1 is a system diagram of an air conditioner provided with an air filter clogging detection device of the present invention.

FIG. 2 is a cross-sectional view of the indoor unit of the air conditioner as viewed from a side.

FIG. 3 is a block diagram showing an electrical configuration of an air filter clogging detection device according to the present invention, and corresponds to claims 1 and 2;

FIG. 4 is a table showing a relationship between a combination of modes to be changed and a reference width at that time, which is stored in an internal memory of a comparison unit in advance.

FIG. 5 is a flowchart illustrating an operation of the air conditioner including the air filter clogging detection device illustrated in FIG. 3;

FIG. 6 is a block diagram showing another embodiment of the air filter clogging detection device according to the present invention, and FIGS.
It corresponds to.

FIG. 7 is a flowchart illustrating an operation of the air conditioner including the air filter clogging detection device illustrated in FIG. 6;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 compressor (refrigerant compressor) 2 four-way valve 3 indoor heat exchanger 4 decompressor 5 outdoor heat exchanger 7 temperature sensor (temperature detection means) 21 comparison unit 22 operation control unit (including rotation mode change unit) 23 operation time Accumulation unit 24 Timer unit 25 Input unit 26 Warning unit 27 Time determination unit 31 Indoor fan 38 Air filter

Claims (4)

[Claims] 1. A refrigerant compressor, an indoor heat exchanger having an air filter disposed on a front surface thereof, an indoor fan, an outdoor heat exchanger, an outdoor fan, the indoor heat exchanger, and the outdoor heat exchanger. An air conditioner having a refrigerating cycle formed by a decompressor interposed between the refrigerant compressor and a four-way valve for switching the connection between the refrigerant compressor and the indoor heat exchanger or the outdoor heat exchanger. Temperature detection means for detecting the conduit temperature of the indoor heat exchanger, operation time integration means for integrating the operation time of heating or cooling, and after the start of heating operation or cooling operation, a predetermined operation time by the operation time integration means Each time the accumulation is performed, the rotation mode of the indoor fan is changed from the previous mode for a certain period of time to continue the operation, and the rotation mode of the indoor fan is changed to operate. During a certain period of time, the temperature change of the conduit temperature of the indoor heat exchanger detected by the temperature detecting means is monitored to determine the change width, and the obtained change width and a reference width previously set inside. And a warning unit for warning the time of replacement of the air filter based on the comparison result of the comparison unit, when the change width of the conduit temperature is smaller than the reference width. Air filter clogging detector for air conditioners. 2. A plurality of types of the reference width are set according to a combination of a previous rotation mode of the indoor fan and another rotation mode that changes from the rotation mode for a predetermined time. 2. The air filter according to claim 1, wherein a reference width is selected from a plurality of types of reference widths based on the previous rotation mode of the indoor fan and is set inside. Clog detection device. 3. If the change width of the conduit temperature obtained by the comparing means is larger than the reference width, the next predetermined time accumulated by the operating time integrating means based on the difference between the change width and the reference width. The air filter clogging detection device for an air conditioner according to claim 1 or 2, further comprising time determination means for determining the operation time of the air conditioner. 4. The time determining means determines that the larger the difference between the change width and the reference width is, the longer the next predetermined operation time integrated by the operation time integrating means is, and determines the change width and the reference value. 4. The air filter clogging detection device for an air conditioner according to claim 3, wherein the determination is made such that the smaller the difference from the width is, the shorter the next predetermined operation time integrated by the operation time integration means is.