JP2008209051A - Air conditioning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioning device which suppresses growing of molds, by detecting water attached to an indoor unit and surely evaporating the water by heating. <P>SOLUTION: This air conditioning device comprises: a detecting means for detecting water attached to a fan blade 5b of an air distribution fan 5 of the indoor unit 1; a heating means for drying the inside of the indoor unit 1; and a control device for controlling the heating means on the basis of a signal from the detecting means. The water attached to the fan blade 5b of the air distribution fan 5 is detected by an optical sensor of the detecting means, and the inside of the indoor unit 1 is dried by the heating means, so that the water does not remain, the growing of molds is suppressed, and the inside of the indoor unit is kept in a desired sanitary conditions. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an air conditioner having a function of suppressing mold growth.

  As a method of suppressing the growth of mold in the air conditioner, an operation of drying the inside after the cooling operation of the air conditioner is normally performed, and temperature detection by a thermistor for detecting the temperature of the blower fan or the heat exchanger is performed. A method of performing heating control by means of a timer at a predetermined time and a predetermined time interval is generally performed (see, for example, Patent Document 1).

  In addition, a sensor that detects dew condensation is provided near the surface of the heat exchanger of the air conditioner.When it is determined that dew condensation has occurred, the heat exchanger is heated to perform a drying operation, and the surface temperature of the heat exchanger is Is kept at the protein denaturation temperature of microorganisms by a temperature sensor to suppress mold growth (see, for example, Patent Document 2).

In addition, examples of molds that propagate on blower fans of air conditioners include the genus Cladosporium, the Penicillium genus, and the Aspergillus genus. It is known (see, for example, Non-Patent Document 1).
JP 2005-61741 A JP 2006-138545 A “Odor generating characteristics of several types of fungi”, life hygiene, Vol. 43, No. 4, pp. 135-143 (1999)

Mold growth in the indoor unit of an air conditioner is caused by mold spores in the air caused by water adhering to the inside, but the growth of mold by the thermistor and timer according to the conventional patent document 1 is suppressed. In the method, a method is used in which the spores and mycelia of mold are thermally damaged by heating for a predetermined time every predetermined operation time, thereby suppressing the growth.
Further, in the method according to Patent Document 2 provided with a sensor for detecting dew condensation, after switching to dehumidification cycle operation and allowing dew condensation water to adhere to the surface of the indoor heat exchanger, the temperature is higher than the protein denaturation temperature of microorganisms in high temperature heating cycle operation And hold for a predetermined time to inactivate microorganisms to suppress growth.

  However, since any of the above conventional methods controls the heating by time, it does not directly detect the absence of water adhering to the interior of the indoor unit after heating, and the remaining water due to insufficient transpiration of water. In addition, the heating time tends to be long, and there is a problem of increasing power consumption and deteriorating the plastic material. For this reason, there was a problem that mold growth could not be sufficiently suppressed.

  The present invention has been made to solve the above-described problems, and detects air adhering to an indoor unit, and air that can suppress mold growth by reliably evaporating water by heating. It aims to provide a harmony device.

  In order to solve the above problems, an air conditioner according to the present invention includes a detection unit that detects water attached to a fan blade of a blower fan of an indoor unit, a heating unit that dries the interior of the indoor unit, and a detection unit. And a control device for controlling the heating means by a signal.

  According to this problem solving means, the growth of mold can be suppressed by evaporating the water adhering to the indoor unit and drying it.

  According to the air conditioner of the present invention, the water adhering to the fan blades of the blower fan is detected by the detecting means, and the interior of the indoor unit is dried by the heating means, so there is no residual water and mold growth. And the indoor unit can be maintained in good hygiene.

Hereinafter, the configuration and operation of an air-conditioning apparatus according to an embodiment of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a sectional view showing the configuration of an indoor unit of an air-conditioning apparatus according to Embodiment 1 of the present invention. FIG. 2 is a structural cross-sectional view of a main part of the blower fan of the indoor unit.
As shown in FIG. 1, a suction grill 2 is provided at the top of the indoor unit 1. Inside the indoor unit 1, there are a filter 3 below the suction grill 2, a heat exchanger 4 below the filter 3, A blower fan 5 is provided at a position surrounded by the heat exchanger 4, a drain pan 6 is provided at the lower part of the heat exchanger 4, and an optical sensor that is a detection means for detecting water in the vicinity of the blower fan 5. A unit 7 and a drying heater 8 as heating means are provided, and a control device 9 for controlling the heater 8 is provided. A blowout louver 11 that can be opened and closed is provided at the blowout port 10 of the indoor unit 1. Is provided.
As shown in the main part of the blower fan in FIG. 2, a fan blade 5b is attached to the blower fan 5, and the light emitting element 7t disposed at a position symmetrical to the normal line 5h of the curved surface of the fan blade 5b; An optical sensor unit 7 having an optical sensor combined with the light receiving element 7r is disposed, and the optical sensor unit 7 is connected to a control device 9. Within the control device 9, there are a drive circuit 12 for sending a signal to the light emitting element 7t, a processing circuit 13 for judging the output signal of the light receiving element 7r, and a heater control circuit 14 for operating the heater 8 by the signal of the processing circuit 13. There is.

  When the air conditioner is in cooling operation, the heat exchanger 4 of the indoor unit 1 is in a cooled state, and moisture in the air tends to condense. Most of the condensed moisture is collected in the drain pan 6 and discharged to the outside, but part of it is scattered and adheres to the blade 5b of the blower fan 5. Alternatively, when the cooling operation is stopped, the indoor unit 1 keeps the cooled state for a while, and therefore, when air flows from the outside of the indoor unit 1, the inside of the indoor unit 1 such as the surface of the fan blade 5b is condensed. As a result of observing the state of the blower fan 5 in detail, adhering water and condensed water (attached water) are affected by the centrifugal force due to the rotation of the blower fan 5, and the humidity inside the blower fan 5 is higher than the outside. It became clear that it was easy to remain on the entire surface of the tip portion of the fan blade 5b and the concave portion of the fan blade 5b due to being high. In any case, since water tends to remain on the surface of the blade 5b of the blower fan 5, mold is likely to grow if left untreated. When mold grows, a so-called mold odor is generated from the outlet 10 of the indoor unit 1 when the air conditioner is restarted. In addition, when mold grows in large quantities, the space between the fan blades 5b is also blocked, resulting in a decrease in air volume and heat exchange efficiency and noise.

The inventors individually examined the components inside the indoor unit that has been used for a long period of time, and performed microscopic observation and microbial analysis of the soiled substances adhering to the interior. As a result, it was confirmed that the contaminants adhering to the surface of the blower fan had almost no dust, and almost all were mold mycelium and thick film cells. The mold concentration was about 10 ³ to 10 ⁴ per 1 cm ² . On the other hand, filter, drain pan and the heat exchanger is a fungus concentration of 10 about ^two from 1 cm ² per 10 ^1, fungal contamination of the blower fan has been found to be particularly pronounced than the other members. From this, the mold odor is eliminated by removing the water adhering to the blower fan.

Next, the operation of the air-conditioning apparatus according to Embodiment 1 will be described with reference to FIG. 1 and FIG.
During operation of the air conditioner, indoor air is taken into the indoor unit 1 from the suction grill 2 by the blower fan 5, and the air taken in by the heat exchanger 4 is heat-exchanged, passes through the blower fan 5, and blown out louver 11. The air-conditioned air is sent out into the room from the outlet 10 to which is attached. During the cooling or dehumidifying operation, the dew condensation water generated by aggregation in the heat exchanger 4 is collected by the drain pan 6 and discharged outside. At this time, the humidity in the indoor unit 1 becomes high, and the dew condensation is likely to occur. In particular, water tends to adhere to the fan blade 5b of the blower fan 5, and an environment suitable for the growth of microorganisms such as mold is obtained. If the air conditioner is stopped in this state, microorganisms such as mold grow and cause bad odor, which is not preferable for health.

  Therefore, it is determined whether water is attached to the fan blade 5b every predetermined time when the air conditioning apparatus 1 is performing cooling operation or dehumidifying operation or when the air conditioning apparatus 1 is stopped. If it adheres, the heater 8 is heated to dry the interior of the indoor unit 1. That is, the light radiated from the light emitting element 7t of the optical sensor unit 7 by the drive circuit 12 to the fan blade 5b of the blower fan 5 for sucking and sending air is reflected on the surface of the fan blade 5b and the reflected light thereof. Is received by the light receiving element 7r of the optical sensor unit 7. If water adheres to the surface of the fan blade 5b, a change in reflectance, a scattering of light, and a shift in reflection angle occur, so the amount of light received by the light receiving element 7r decreases. When the processing circuit 13 determines that the output voltage V obtained by amplifying the output of the light receiving element 7r is equal to or lower than the preset voltage V1, a signal is sent to the heater control circuit 14 to supply power to the heater 8. If the processing circuit 13 determines that the output voltage V from the light receiving element 7r is equal to or higher than the preset voltage V2, a signal is sent to the heater control circuit 14 to turn on the power of the heater 8. Cut it. Here, V1 is the output voltage V of the light receiving element 7r that determines whether the heater 8 is turned on, and is set higher than the output voltage Vw when the fan blade 5b is wet. V2 is an output voltage V of the light receiving element for determining that the heater 8 is turned off, and is set lower than the output voltage Vd when the fan blade 5b is completely dry. When the fan blade 5b is in a dry state, the drying of the inside of the indoor unit 1 is also completed.

  Here, it is not always necessary to energize the heater 8 until the fan blade 5b is completely dried, and V2 is set in a state in which water has not been completely removed. This is because the inside of 1 is heated and dried by blowing air. If the heating time is adjusted in advance in consideration of the time from when the power of the heater 8 is shut off until water is evaporated and dried, the heating time of the heater 8 can be shortened and the power consumption can be reduced. .

  Next, FIG. 3 is an example showing a measurement result of detecting water adhering to the fan blade 5b according to the first embodiment. A visible light emitting diode having an emission wavelength of 610 nm and a light beam emission angle of 10 degrees was used as the light emitting element 7t. A pin photodiode was used for the light receiving element 7r. The measurement was performed by operating only the blower fan 5 without performing the cooling operation. In FIG. 4, the horizontal axis indicates the elapsed time T, and the vertical axis indicates the output voltage V of the light receiving element 7r. Measurements were taken at 10 second intervals. First, the operation of the blower fan 5 was started, and after confirming that it was in a steady state after 2 minutes, water droplets were attached to the surface of the fan blade 5b by spraying. Here, the blower fan 5 was measured in a state rotated at 100 rpm. When there is no water droplet, the output voltage V was 1.7 V, but it is drastically reduced to 0.7 V at the same time as landing. This is because the water droplets scatter light and the amount of light reaching the light receiving element 7r is reduced. If the operation of the blower fan 5 is continued in this state, the output voltage V gradually increases. This corresponds to the fact that the surface of the fan blade 5b is gradually dried and water drops are reduced. Furthermore, when the operation was continued, it was confirmed that the output voltage V returned to 1.7 V in the initial state after about 30 minutes. At this time, when the rotation of the blower fan 5 was stopped and visually observed, it was confirmed that no water droplets adhered to the surface of the fan blade 5b.

  From this result, for example, if V1 is set to 0.9V and V2 is set to 1.46V, it is determined that the output voltage V is equal to or lower than V1 and water is attached to the fan blade 5b. Adhesion water will decrease in a short time if heat is added. When the output voltage reaches V2, the heater 8 is turned off and the drying operation is completed. The output voltage V fluctuates because the fan blade 5b rotates and the distance from the optical sensor unit 7 fluctuates. Although the method of detecting the water adhering to the fan blade 5b with the optical sensor unit 7 in a state where the blower fan 5 is stopped may be used, the time average of the output voltage V is measured with the blower fan 5 being rotated. By processing, the variation error can be minimized. In addition, it is also effective to increase the accuracy to modulate the light emitted from the light emitting element with a specific frequency to eliminate the influence of disturbance light.

In addition, in order to detect the presence or absence of water adhering to the surface of the fan blade 5b with high sensitivity, the light emitting element 7t and the light receiving element 7r of the optical sensor unit 7 are in a positional relationship of optical reflection conditions, and light emission of the light emitting element A smaller angle is preferred.
Further, in order to increase the amount of reflected light and improve the light receiving sensitivity, it is desirable to increase the reflectivity by subjecting the surface of the fan blade 5b to an optical reflection process such as metal vapor deposition. In addition to vapor deposition, a method of forming a metal coating layer by ion plating or plating, or a method of attaching a metal plate or metal foil tape may be used.

In consideration of the variation of the water adhering between the fan blades 5b, the error is reduced by taking the position average of the output voltages V of the light receiving elements 7r from the plurality of fan blades 5b using the plurality of optical sensor units 7. Therefore, it is effective to improve the accuracy to detect the presence or absence of the adhered water using this average value. In any case, it is preferable to perform measurement with the blower fan 5 rotated.
Further, the output voltage may change due to a change in the reflectance of the fan blade over time or the deterioration of the light emitting element, and the calibration is periodically performed based on the output voltage Vd in the dry state (see FIG. 3). To correct V2. In addition, it is also effective to correct V1 at a constant ratio with respect to V2.

  FIG. 4 shows the measurement result of the light wavelength dependence of the detection sensitivity depending on whether or not the fan blade 5b has landed. The light emitting element 7t has different light emission of 380 nm (purple), 470 nm (blue), 520 nm (green), 591 nm (yellow), 610 nm (orange), 630 nm (red), 950 nm (infrared), and 1200 nm (infrared). It was carried out under the same conditions using a light emitting diode of wavelength. The emission angle of each light emitting diode was 10 degrees. The ambient temperature during the measurement was 28 ° C., and the relative humidity was 65%. The horizontal axis of FIG. 4 indicates the light wavelength, and the vertical axis indicates the ratio of the output voltage Vd in the state where water is not attached to the output voltage Vw in the state where water is attached to the fan blade 5b, that is, the detection sensitivity (Vd / Vw). The higher this value, the higher the SN ratio, which means that water can be detected with high sensitivity. As is clear from this figure, it was found that at a wavelength shorter than 630 nm, the ratio of detection sensitivity is high and the sensitivity is high. In particular, in order to detect water with high sensitivity, it is preferable to use a light source having a light wavelength of 380 nm to 530 nm.

  Note that the emission wavelength of the light emitting diode used above indicates the center wavelength of the emission spectrum, but it is not necessarily this value, and any light emitting element having an emission wavelength in this range may be used. In the above measurement, a light-emitting diode is used as the light-emitting element 7t. However, other light sources such as a laser diode, a xenon lamp, and a halogen lamp may be used. The same effect can be expected for the light receiving element 7r even if it is a CMOS sensor, a photomultiplier, a CCD, or the like in addition to a Pin photodiode. Further, an element having a wide spectral distribution, such as a white light emitting diode or a xenon lamp, can be used as the light emitting element 7t. However, an optical device that transmits or reflects only light in a specific narrow wavelength band, such as a bandpass filter, is used. It is also possible to use a combination with a shutter that can pass through or shut off.

Next, an example of an operation procedure for executing an indoor unit drying operation in the air-conditioning apparatus of Embodiment 1 will be described with reference to the flowcharts of FIGS. 5 to 7.
FIG. 5 explains the entire procedure of the indoor unit drying operation process. First, in a state where the air conditioner is being operated (step S1), it is determined whether or not the operation time has passed a predetermined time (step S2). Next, if the predetermined time has elapsed, it is determined whether the operation mode is a cooling operation or a dehumidifying operation (step S3). In any operation mode, it is determined whether the drying operation is set (step S4). If the drying operation is set, the drying operation is executed (step 5). At this time, the operation mode is temporarily stopped (step 6). When the drying operation is completed, the original operation mode is restored. However, if the drying operation button is pressed at an arbitrary time, the process starts from step 3.

  FIG. 6 explains the procedure of the drying operation of the indoor unit. When the drying operation is started, the output voltage of the light receiving element 7r of the optical sensor unit 7 is monitored, and if it is equal to or lower than V1 (step S7), it is confirmed whether the blowing louver is closed or opened (step S8). If it is open, it is closed (step S12), and then the heater 8 is turned on (step S9), and the indoor unit 1 is dried. When the output voltage becomes equal to or higher than V2 (step S10), the heater 8 is turned off and the drying operation is finished (step S11).

  FIG. 7 explains the procedure of the drying operation of the indoor unit when the operation is stopped. It is confirmed whether or not there is a drying operation setting at the end of the operation (step S13). If it is set, a drying operation is performed (step S14), and an operation end process is performed (step S15).

  As described above, the air conditioner according to Embodiment 1 detects that water has adhered to the fan blade of the blower fan by the optical sensor, performs heating to dry the interior of the indoor unit, evaporates the water, Since the drying operation is stopped in a state where there is no loss, the interior unit can be reliably kept in a dry state, and the growth of microorganisms such as mold can be suppressed and the effect of being able to maintain a good hygiene state. is there.

Embodiment 2. FIG.
FIG. 8 is a side cross-sectional view of the periphery of the optical sensor unit according to Embodiment 2 of the present invention.
As shown in FIG. 8, optical fibers 15 and 16 as light guiding means are respectively attached to the light emitting element 7 t and the light receiving element 7 r of the optical sensor unit 7, and the other ends of the optical fibers 15 and 16 are connected to the blower fan 5. It is arrange | positioned in the fan blade 5b vicinity. The optical fiber 15 and the optical fiber 16 are installed at positions symmetrical with respect to the normal line 5h of the fan blade 5b. Other configurations are the same as those of the first embodiment shown in FIG.

Next, the operation of the air-conditioning apparatus according to Embodiment 2 will be described with reference to FIG.
The light emitted from the light emitting element 7t of the optical sensor unit 7 is propagated to the optical fiber 15, the emitted light is reflected by the surface of the fan blade 5b, and the reflected light is incident and propagated to the optical fiber 16 to the light receiving element 7r. Led. Whether or not to turn on the heater 8 by the output voltage V from the light receiving element 7r is determined by the processing circuit 13 in the control device 9, and is controlled by the heater control circuit 14 that operates the heater 8. Here, although the case where an optical fiber is used as the light guide means has been described, a sheet-like light guide plate or the like may be used.

  As described above, the air conditioner according to the second embodiment detects the adhesion of the water of the fan blade using the light guiding means, so that in addition to the effects of the first embodiment, the optical sensor unit When it is difficult to dispose near the blower fan, there is an effect that the optical sensor unit can be freely installed at a distant position.

  In addition, although the case where the heater 8 for drying was installed was demonstrated in embodiment as a heating means, the auxiliary heater for heating incorporated in the indoor unit can also be utilized. Moreover, it is also possible to dry using a heat exchanger by setting it as the heating operation mode by a heat pump.

  In the embodiment, the fan blade has a curved surface. However, the fan blade may have a flat surface or other shapes.

  Moreover, in the figure, the same code | symbol shows the same or an equivalent part.

It is side surface sectional drawing which shows the indoor unit of the air conditioning apparatus which concerns on Embodiment 1. FIG. It is side surface sectional drawing of the optical sensor unit periphery part of the air conditioning apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the detection result of the water adhering to the fan blade in the air conditioning apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the result of the optical wavelength dependence of the detection sensitivity in the air conditioning apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the whole procedure of the drying operation process of the indoor unit in the air conditioning apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the procedure of the drying operation of the indoor unit in the air conditioning apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the procedure of the drying operation of the indoor unit at the time of the operation stop in the air conditioning apparatus which concerns on Embodiment 1. FIG. It is side surface sectional drawing of the optical sensor unit periphery part of the air conditioning apparatus which concerns on Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Indoor unit 4 Heat exchanger 5 Blower fan 5b Fan blade 7 Optical sensor unit 7t Light emitting element 7r Light receiving element 8 Heater 9 Control apparatus 15, 16 Optical fiber

Claims (7)

Detecting means for detecting water adhering to the fan blade of the blower fan of the indoor unit;
Heating means for drying the interior of the indoor unit;
A control device for controlling the heating means by a signal from the detection means;
An air conditioner comprising:   The air conditioner according to claim 1, wherein the detecting means is an optical sensor including a light emitting element and a light receiving element.   The air conditioner according to claim 1, wherein the detection means is a light sensor having a light guide means between the light emitting element and the light receiving element and the fan blade.   The air conditioning apparatus according to claim 2 or 3, wherein the fan blade surface is subjected to an optical reflection treatment.   The air conditioning apparatus according to claim 2 or 3, wherein the light emitting element has an emission wavelength of 380 to 630 nm.   It detects in the state which rotated the ventilation fan, The air conditioning apparatus of Claim 2 or Claim 3 characterized by the above-mentioned.   The air conditioning apparatus according to claim 6, wherein an output signal from the light receiving element is averaged.

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