A system for controlling self-cleaning process in an air conditioner

Abstract

The present invention relates to a system (100) for controlling self-cleaning process in an air conditioner. The system (100) comprises an indoor temperature sensor (101), an indoor humidity sensor (102) and an outdoor temperature sensor (103), and a controller (104) for adjusting operation of the air conditioner to control the self-cleaning process. The controller (104) is configured 0 for determining a condensate amount generated using outputs from the indoor temperature sensor (101), the indoor humidity sensor (102) and the outdoor temperature sensor (103) under a cooling operation, subsequently comparing the condensate amount with a target condensate amount. The controller (104) terminates the cooling operation once the condensate amount meets the target 5 condensate amount. Further, the present invention relates to a method for controlling self-cleaning process by the system (100).

Description

[0001] A SYSTEM FOR CONTROLLING SELF-CLEANING PROCESS IN AN AIR CONDITIONER FIELD OF THE INVENTION

[0002] The present invention relates to maintenance of an air conditioner. More particularly, the present invention relates to a system for controlling self-cleaning process in an indoor unit of an air conditioner and a method therefor.

[0003] BACKGROUND OF THE INVENTION

[0004] Maintenance of an air conditioner is essential for ensuring efficient operation, prolonging its lifespan, and preserving good indoor air quality. As ambient air is continuously drawn into the indoor unit of the air conditioner, its components such as an air filter and a heat exchanger can easily accumulate dirt and become clogged over time as the air conditioner operates. While the air filter is relatively easy to clean, the heat exchanger seems to be more challenging to clean due to its structure and configuration. Dust buildup in the heat exchanger, especially between layers of metal fins, can form an insulation layer which may eventually lead to overheating of the indoor unit. Therefore, regular maintenance and cleaning of the heat exchanger becomes a necessity to ensure a proper functioning of the indoor unit and thus a stable operation of the air conditioner over time.

[0005] There are a number of examples over the prior art aiming to provide a system for performing self-cleaning in an indoor unit of an air conditioner without human intervention. During the self-cleaning process, the operation of the air conditioner is manipulated to create condensate or frost on a surface of the heat exchanger in the indoor unit. Dirt and dust adhered on the surface of the heat exchanger could be washed away when the frost is melted or the condensate is flushed away. As such, the cleanliness of the heat exchanger as well as the indoor unit can be maintained without having a technician to be on site.Prior art document JP2020115063A discloses an air conditioner that performs self-cleaning via moist heat sterilization for suppressing mold growth. During the self-cleaning process, the rotation speed of the blower fan is determined based on the operating time of the cooling operation as the amount of dew condensation water generated in the indoor heat exchanger depends on the operating time of the cooling operation. Also, the rotation speed of the blower fan may be determined based on the humidity detected by a humidity sensor arranged inside the indoor unit as the amount of condensed water generated in the heat exchanger depends on the humidity inside the indoor unit. Nevertheless, the prior art does not disclose on how to determine and adjust the operating time of cooling operation based on the amount of dew condensation water generated in the indoor heat exchanger. Furthermore, there is no clear disclosure in the prior art on how to determine or estimate the amount of dew condensation water generated in the indoor heat exchanger.

[0006] There is a prior art document CN110173828B that discloses a selfcleaning method of an air conditioner, in which the self-cleaning method involves controlling the air conditioner to operate under a cooling mode to generate condensation and frost on the surface of an indoor heat exchanger, and controlling the air conditioner to operate under a heating mode to defrost the indoor heat exchanger when the duration of the cooling mode reaches a target duration. The target duration is determined according to the indoor humidity which is negatively correlated to the target duration. Nevertheless, the prior art does not provide disclosure on how to determine the condensation condition in the indoor heat exchanger and utilize thereof for determining whether the condensate is sufficient for the self-cleaning process, rather than solely depending on the target duration.

[0007] Another prior art document JP2021135006A discloses an air conditioning system that is capable of cleaning an indoor heat exchanger, while suppressing imparting discomfort to a user. The indoor control unit is configured to determine whether the cleaning process has been completed based on a dew point temperature and a cooling time corresponding to a combination of the roomtemperature detected by a room temperature sensor and a humidity detected by a humidity sensor. In an example, when the temperature of the indoor exchanger is detected equal to or lower than the dew point temperature, the indoor control unit measures the current duration of that state. When the measured duration reached the cooling time, the indoor control unit will determine that the cleaning process can be completed. However, the prior art does not take into account the condensation condition in the indoor heat exchanger for determining the adequacy of the cleaning process in a more effective manner.

[0008] Accordingly, it can be seen in the prior art documents that there exists a need to have a system that is capable of controlling self-cleaning in an indoor unit of an air conditioner more accurately by real-time determination of condensate generated in a heat exchanger, considering both indoor and outdoor conditions.

[0009] SUMMARY OF INVENTION

[0010] An object of the present invention is to provide a system for controlling self-cleaning process in an indoor unit of an air conditioner by real-time determination and monitoring of condensate amount generated in a heat exchanger, so that cleanliness of the indoor unit can be maintained in a much more efficient manner.

[0011] Another object of the present invention is to provide a system for controlling self-cleaning process in an indoor unit of an air conditioner with consideration of indoor and outdoor conditions.

[0012] A further object of the present invention is to provide a system for controlling self-cleaning process in an indoor unit of an air conditioner that is capable of dynamically adjusting a duration for the self-cleaning process based on varying indoor and outdoor conditions, thereby optimizing or even shortening overall duration for the self-cleaning process to take place.Also, an object of the present invention is to provide a system for controlling self-cleaning process in an indoor unit of an air conditioner without requiring a technician to be on site.

[0013] Accordingly, these objects are achievable by following the disclosure and teachings of the present invention. The present invention relates to a system for controlling self-cleaning process in an indoor unit of an air conditioner, in which the system comprising a first sensor for detecting an indoor ambient temperature, a second sensor for detecting an indoor humidity, a third sensor for detecting an outdoor ambient temperature, and a controller for adjusting operation of the air conditioner to control the self-cleaning process. The controller is configured for receiving inputs including the detected indoor ambient temperature from the first sensor, the detected indoor humidity from the second sensor and the detected outdoor ambient temperature from the third sensor during a cooling operation of the air conditioner, processing the receiving inputs to determine a condensate amount generated in the indoor unit, subsequently comparing the condensate amount generated with a target condensate amount for the self-cleaning process. Further, the controller is configured for terminating the cooling operation once the condensate amount generated meets the target condensate amount.

[0014] The controller is configured for constantly determining the condensate amount generated until the target condensate amount is met. The controller will determine the condensate amount generated using the detected indoor ambient temperature, the detected indoor humidity and the detected outdoor ambient temperature via the equation of:

[0015] C

[0016]

[0017] T= a + b (TID) + c (HID) + d (T0D) + e (Tm)2+ f (HID)2+ g(T0D)2

[0018] + h(TID)(HID) + i (T / D)(T0D) + j (HID)(T0D+ k (TID(HID)(T0D)

[0019] where CT denotes the condensate amount generated; TID denotes the detected indoor ambient temperature; HID denotes the detected indoor humidity; TOD denotes the detected outdoor ambient temperature; and a, b, c, d, e, f, g, h, i, j and k are constant values.The controller is configured for controlling an indoor fan to operate at a pre-determined rotating speed according to the detected indoor humidity and directing an air outlet flap towards a pre-determined angle during the cooling operation to generate sufficient condensate amount so as to meet the target condensate amount for self-cleaning. The controller controls the indoor fan to operate at at least an intermediate speed during the cooling operation. Preferably, the pre-determined angle of the air outlet flap is at least more than 5° from a fully closed position of the air outlet flap.

[0020] Further, the controller is configured for switching to an operation for drying the indoor unit after terminating the cooling operation. The controller will switch off a compressor of the indoor unit, and set any one or a combination of a rotating speed of an indoor fan and an angle of an air outlet flap to a fixed value for drying the indoor unit after ending the cooling operation. In a more preferred embodiment of the present invention, the controller sets the rotating speed of the indoor fan to at least an intermediate speed for drying the indoor unit. The controller sets the angle of the air outlet flap to at least more than 5° from a fully closed position of the air outlet flap.

[0021] The controller is configured for determining a duration for drying the indoor unit using the detected indoor ambient temperature and the detected indoor humidity. The duration for drying the indoor unit will be determined via the equation of:

[0022] T

[0023]

[0024] mD= a + b (TID) + c (HID) + d (TID)2+ e (HID)2+ / (T / D)(tf / D)

[0025] where Tmo denotes the duration for drying the indoor unit; TID denotes the detected indoor ambient temperature; HID denotes the detected indoor humidity; and a, b, c, d, e and f are constant values.In a preferred embodiment of the present invention, the target condensate amount is pre-determined based on a manufacturer’s predefined configuration setting.

[0026] Further, the condensate is preferably condensed water generated in a heat exchanger of the indoor unit. Moreover, the indoor ambient temperature is preferably indoor dry bulb temperature, while the outdoor ambient temperature is preferably outdoor dry bulb temperature.

[0027] In a preferred embodiment of the present invention, the second sensor is a relative humidity sensor for detecting relative humidity of an indoor environment. Moreover, the first sensor, the second sensor and the third sensor are preferably existing sensors in the air conditioner. In another embodiment of the present invention, the first sensor and the second sensor can be integrated to become a single sensor, in which the single sensor can be an existing sensor in the air conditioner.

[0028] According to another aspect of the present invention, an air conditioner comprising an indoor unit with the above-described system is provided

[0029] According to another aspect of the present invention, there is provided a method for controlling self-cleaning process by the aforementioned system in an indoor unit of an air conditioner, in which the method comprises detecting an indoor ambient temperature using a first sensor, detecting an indoor humidity using a second sensor, detecting an outdoor ambient temperature using a third sensor, receiving inputs including the detected indoor ambient temperature, the detected indoor humidity and the detected outdoor ambient temperature during a cooling operation of the air conditioner from the first sensor, the second sensor and the third sensor, by a controller, processing the received inputs to determine a condensate amount generated in the indoor unit, by the controller, comparing the condensate amount generated with a target condensate amount for the selfcleaning process, by the controller, and ending the cooling operation once the target amount of condensate is achieved, by the controller.BRIEF DESCIRPTION OF THE ACCOMPANYING DRAWINGS

[0030] The features of the invention will be readily understood and appreciated from the following detailed description when read in conjunction with the accompanying drawings of the preferred embodiments of the present invention, in which:

[0031] Figure 1 illustrates a simplified configuration of a system for controlling self-cleaning process in an air conditioner according to a preferred embodiment of the present invention.

[0032] Figure 2 illustrates a flowchart demonstrating an example of a processing procedure by a controller in an air conditioner having a system for controlling selfcleaning process in an indoor unit according to a preferred embodiment of the present invention.

[0033] Figure 3 is a line chart illustrating relationship between an amount of condensate generated in a heat exchanger of an indoor unit and outdoor ambient temperature.

[0034] Figure 4 illustrates a line-bar chart showing a plurality of condensate amount generated in a heat exchanger of an indoor unit as indoor temperature decreases.

[0035] Figure 5 illustrates a bar chart showing comparison on overall durations for self-cleaning process between an existing method and the present invention, under decreasing indoor temperature condition.

[0036] Figure 6 illustrates a line-bar chart showing a plurality of condensate amount generated in a heat exchanger of an indoor unit under constant indoor temperature condition.Figure 7 illustrates a bar chart showing comparison on overall durations for self-cleaning process between an existing method and the present invention, under constant indoor temperature condition.

[0037] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] The abovementioned and other features and objects of this invention will become more apparent and better understood by reference to the following detailed description. It should be understood that the detailed description made known below is not intended to be exhaustive or limit the invention to the precise form disclosed as the invention may assume various alternative forms. All the relevant modifications and alterations made to the present invention as covered in the detailed description should be construed to fall within the scope of the appended claims. Therefore, the configuration of the invention is not limited to the configuration mentioned in the following description.

[0039] The present invention relates to a system (100) for controlling selfcleaning process in an indoor unit of an air conditioner, and an air conditioner comprising the system (100) thereof, aiming to accelerate the self-cleaning process in the indoor unit while ensuring the self-cleaning process effectively removes dust and dirt accumulated in a heat exchanger. The system (100) is also aimed to improve the self-cleaning process in the indoor unit by taking into account both indoor and outdoor conditions. At the same time, the system (100) is configured to continuously determine condensate amount generated in the heat exchanger and monitor thereof in real time, thereby optimizing overall duration required for the self-cleaning process. With that, cleanliness of the heat exchanger and the indoor unit can be effectively maintained on a regular basis without any delays. Furthermore, the self-cleaning process does not require a fixed duration, as the system (100) can assess and determine if the process can be completed sooner, without relying on a pre-set time interval.

[0040] Figure 1 shows a simplified configuration of the system (100) for use in an air conditioner for controlling self-cleaning process in an indoor unit according toa preferred embodiment of the present invention. The system (100) of the present invention comprises a first sensor (101) for detecting an indoor ambient temperature, the second sensor (102) for detecting an indoor humidity, a third sensor (103) for detecting an outdoor ambient temperature, and a controller (104) for adjusting operation of the air conditioner to control the self-cleaning process using the data outputted by the first sensor (101), the second sensor (102) and the third sensor (103) respectively.

[0041] In a preferred embodiment of the present invention, the controller (104) is configured for receiving inputs including the detected indoor ambient temperature from the first sensor (101), the detected indoor humidity from the second sensor (102) and the detected outdoor ambient temperature from the third sensor (103) during a cooling operation of the air conditioner, processing the received inputs to determine a condensate amount generated in the indoor unit, subsequently comparing the condensate amount generated with a target condensate amount for the self-cleaning process. More preferably, the controller (104) is constantly receiving inputs from the first sensor (101), the second sensor (102) and the third sensor (103), determining the condensate amount generated and comparing thereof with the target condensate amount at a pre-determined interval until the target condensate amount is met. The pre-determined interval may be any interval and is preferably set between 5 to 15 minutes. Once the condensate amount generated meets the target condensate amount, the controller (104) will then terminate the cooling operation. Preferably, the condensate is the condensed water generated in a heat exchanger of the indoor unit.

[0042] In a preferred embodiment of the present invention, the controller (104) is configured for determining the condensate amount generated using the detected indoor ambient temperature, the detected indoor humidity and the detected outdoor ambient temperature via the equation of:

[0043] C

[0044]

[0045] T= a + b (TID) + c (HID) + d (T0D) + e (Tm)2+ f (HID)2+ g(T0D)2

[0046] + h(TIDHID) + i (T / D)(TOD) + j (HID)(T0D+ k (TID(HID)(T0D)where CT denotes the condensate amount generated; TID denotes the detected indoor ambient temperature; HID denotes the detected indoor humidity; TOD denotes the detected outdoor ambient temperature; and, a, b, c, d, e, f, g, h, i, j and k are constant values. The constant values could be determined via multiple regression analysis using a plurality of indoor ambient temperature data, a plurality of indoor humidity data and a plurality of outdoor ambient temperature data as input variables, and a plurality of target condensate amount data as output variable. These temperature and humidity data may be obtained by manipulating operating conditions and / or ambient conditions of the air conditioner.

[0047] In a preferred embodiment of the present invention, the controller (104) is configured for controlling an indoor fan (106) to operate at a pre-determined rotating speed according to the detected indoor humidity, and directing an air outlet flap (107) towards a pre-determined angle during the cooling operation to generate sufficient condensate amount so as to meet the target condensate amount for the self-cleaning process. The controller (104) preferably controls the indoor fan (106) to operate at at least an intermediate speed, or a speed higher than the intermediate speed during the cooling operation, while directing the air outlet flap (107) towards the pre-determined angle which is preferably more than 5° from a fully closed position of the air outlet flap (107). In another embodiment of the present invention, the pre-determined angle can be a rated angle at which the air outlet flap (107) is positioned to achieve maximum air flow during operation of the indoor unit.

[0048] In a preferred embodiment of the present invention, the controller (104) is configured for switching to an operation for drying the indoor unit after terminating the cooling operation. The controller (104) will switch off a compressor (105) of the indoor unit, and setting any one or a combination of a rotating speed of an indoor fan (106) and an angle of an air outlet flap (107) to a fixed value for drying the indoor unit after ending the cooling operation. Preferably, the controller (104) sets the rotating speed of the indoor fan (106) to at least an intermediate speed for drying the indoor unit. Also, the controller (104) sets the angle of the air outletflap (107) to at least more than 5° from its fully closed position. In another embodiment of the present invention, the angle of the air outlet flap (107) may remain fixed at the rated angle when switching from the cooling operation to the drying operation.

[0049] In a preferred embodiment of the present invention, the controller (104) is configured for determining a duration for drying the indoor unit using the detected indoor ambient temperature and the detected indoor humidity via the equation of:

[0050] T

[0051]

[0052] mD= a + b (TID) + c (HID) + d (TID)2+ e (HID)2+ / (T / D)(tf / D)

[0053] where Tmo denotes the duration for drying the indoor unit; TID denotes the detected indoor ambient temperature; HID denotes the detected indoor humidity; and, a, b, c, d, e and f are constant values. The constant values could be determined via multiple regression analysis using a plurality of indoor ambient temperature data and a plurality of indoor humidity data as input variables, and a plurality of drying duration data as output variable. These temperature and humidity data may be obtained by manipulating operating conditions and / or ambient conditions of the air conditioner.

[0054] In a preferred embodiment of the present invention, the target condensate amount is pre-determined based on a manufacturer’s predefined configuration setting. The target condensate amount may be arbitrarily determined by the manufacturer or a developer of the system (100) in consideration of the heat exchanger properties such as the heat exchanger’s volume and its coil configuration.

[0055] In a preferred embodiment of the present invention, the first sensor is a temperature sensor disposed in an indoor environment where the indoor unit is installed for obtaining an indoor ambient temperature which is preferably indoor dry bulb temperature. Meanwhile, the second sensor is a relative humidity sensor disposed in the same environment as the first sensor for obtaining relative humidity of the indoor environment. Further, the third sensor (103) is atemperature sensor disposed at an outdoor unit of the air conditioner for obtaining an outdoor ambient temperature which is preferably outdoor dry bulb temperature. The third sensor (103) is preferably located at a position at an air inlet area of the outdoor unit before air passing an outdoor heat exchanger in the outdoor unit. In a preferred embodiment of the present invention, the first sensor (101), the second sensor (102) and the third sensor (103) are preferably existing sensors in the air conditioner. In another preferred embodiment of the present invention, the first sensor (101) and the second sensor (102) are integrated to become a single sensor. The single sensor is preferably an existing sensor in the air conditioner.

[0056] Another embodiment of the preset invention relates to a method for controlling self-cleaning process in the indoor unit of an air conditioner via the aforementioned system (100). The steps of the method have been primarily described and illustrated in the preceding paragraphs. As shown in Figure 2, the method is initiated by receiving a signal for cleaning indoor unit. The signal may be triggered based on a user’s request or / and based on a manufacturer’s predefined timing. Upon receipt of the signal, the self-cleaning process will proceed by switching on the compressor of the indoor unit, adjusting the rotating speed of the indoor fan (106) to a higher speed, and fixing the angle of the air outlet flap (107) to a pre-determined angle so that the air conditioner enters a cooling operation. The pre-determined angle of the air outlet flap (107) is preferably at least more than 5° from its fully closed position. In another embodiment of the present invention, the pre-determined angle can be a rated angle of the air outlet flap (107) at which the air flow is maximized for discharged air during operation of the indoor unit

[0057] During the cooling operation, the method of the present invention includes the step of adjusting the rotating speed of the indoor fan (106), by the controller (104), to operate at a pre-determined rotating speed according to the detected indoor humidity from the second sensor (102). Preferably, the indoor fan (106) is controlled to operate at at least an intermediate speed or a speed higher than the intermediate speed. In one embodiment of the present invention, the indoor fan(106) may be adjusted to a lower speed when the indoor humidity is detected at a lower level. At the same time, the method also includes the step of fixing the air outlet flap (107) at the pre-determined angle, by the controller (104), during the cooling operation in order to generate sufficient condensate amount on the heat exchanger for the self-cleaning process. Preferably, the pre-determined angle of the air outlet flap (107) is at least exceeding 5° from its fully closed position. In another embodiment of the present invention, the angle of the air outlet flap (107) may remain unchanged and fixed at the rated angle for the cooling operation.

[0058] Meanwhile, the method of the present invention further comprises the step of constantly receiving inputs from the first sensor (101), the second sensor (102) and the third sensor (103), by the controller (104), to determine the current condensate amount generated in the heat exchanger using the detected indoor ambient temperature, the detected indoor humidity and the detected outdoor ambient temperature. When the current condensate amount is determined to meet the target condensate amount, the self-cleaning process will end the cooling operation and switch to another operation for drying the indoor unit by switching off the compressor, adjusting the rotating speed of the indoor fan (106) to at least an intermediate speed, and fixing the angle of the air outlet flap to the pre-determined angle. Similarly, the predetermined angle may remain the same as during the cooling operation, in which the predetermined angle is preferably more than 5° from the fully closed position or the rated angle of the air outlet flap (107); whereas the indoor fan (106) is preferably adjusted to a higher or maximum speed. Further, the method also includes the step of determining the duration for drying the indoor unit based on the detected indoor ambient temperature and the detected indoor humidity. Eventually, the self-cleaning process will be ended once the drying operation has been completed within the duration as determined. Preferably, the drying operation is for drying the heat exchanger of the indoor unit.

[0059] Figure 3 shows a relationship between the outdoor ambient temperature and the amount of condensate generated in a heat exchanger of an indoor unit,in which the outdoor ambient temperature is preferably an outdoor dry bulb temperature. It is evident that the outdoor ambient temperature is closely correlated with the amount of condensate generated, in which the amount of condensate decreases as the outdoor ambient temperature increases. Furthermore, determination of condensate amount was performed via the aforedescribed method under a plurality of ambient conditions, and the results were tabulated in Tables 1, 2 and 3.

[0060] Table 1 Determination of condensate amount in millilitre (ml) generated by a heat exchanger of an indoor unit under a plurality of indoor dry bulb temperatures (as denoted by ID DB) and indoor humidity (as denoted by RH) when outdoor dry bulb temperature is 28°C

[0061] \ ID DB

[0062] \ CO

[0063] 24 25 26 27 28 29 30 31 32 RH (%\

[0064] 50 651 700 751 804 858 915 972 1032 1093 60 1044 1106 1169 1234 1301 1369 1440 1511 1585 70 1417 1491 1567 1644 1723 1804 1886 1970 2056 80 1770 1857 1944 2034 2125 2218 2313 2409 2507

[0065]

[0066] Table 2 Determination of condensate amount in millilitre (ml) generated by a heat exchanger of an indoor unit under a plurality of indoor dry bulb temperatures (as denoted by ID DB) and indoor humidity (as denoted by RH) when outdoor dry bulb temperature is 37°C

[0067] \ ID DB

[0068] \ CC)

[0069] 24 25 26 27 28 29 30 31 32 RH (%)\

[0070] 50 528 571 616 663 712 762 814 867 922 60 910 964 1020 1078 1137 1198 1261 1325 1391 70 1271 1337 1403 1472 1542 1614 1688 1763 1840

[0071]

[0072] 80 1613 1689 1766 1846 1927 2010 2094 2181 2268

[0073]

[0074] Table 3 Determination of condensate amount in millilitre (ml) generated by a heat exchanger of an indoor unit under a plurality of indoor dry bulb temperatures (as denoted by ID DB) and indoor humidity (as denoted by RH) when outdoor dry bulb temperature is 43°C

[0075] \ ID DB

[0076] \ CC)

[0077] 24 25 26 27 28 29 30 31 32 RH (%k

[0078] 50 431 471 512 555 599 646 693 743 794

[0079] 60 806 855 906 959 1013 1069 1127 1187 1248

[0080] 70 1159 1219 1280 1343 1407 1473 1541 1610 1681

[0081] 80 1493 1562 1633 1706 1780 1856 1934 2013 2095

[0082]

[0083] Based on the Tables 1, 2 and 3, when the outdoor ambient temperature is lower, the condensate amount generated is determined to be higher. On the other hand, when the indoor ambient temperature is higher, the condensate amount generated is determined to be higher. In addition, the amount of condensate generated is determined to be higher when the indoor humidity levels are higher.

[0084] Figure 4 shows condensate generation by an existing method for selfcleaning under decreasing indoor temperature condition. The process of condensate generation occurs within a pre-set duration of about 60 minutes, resulting in a total condensate amount of 980 ml. Meanwhile, the system (100) of the present invention determines that the target condensate amount under the same conditions is approximately 820 ml, with a duration of about 44 minutes required to achieve this amount. As a result, the duration for condensate generation can be efficiently optimized to minimize power consumption and resource waste. Figure 5 further compares the overall duration required for selfcleaning between the existing method and the present invention. The existingmethod has a pre-set overall self-cleaning duration of about 90 minutes, whereas the present invention reduces that duration from 90 minutes to 74 minutes, thereby accelerating the self-cleaning process.

[0085] Figure 6 shows condensate generation by the existing method for selfcleaning under constant indoor temperature condition, in which the constant indoor temperature conditions can be achieved by aid of ventilation means, for example, having a window opened. The process of condensate generation occurs within a pre-set duration of about 60 minutes, resulting in a total condensate amount of 1400 ml. Meanwhile, the system (100) of the present invention determines that the target condensate amount under the same conditions is approximately 820 ml, with a duration of about 28 minutes required to achieve this amount. Further, the system (100) of the present invention can reduce the duration for drying the heat exchanger, as required by the existing method, from 30 minutes to 21 minutes. With that, the present invention is capable of reducing the overall duration as pre-set by the existing method, from 90 minutes to 49 minutes, as shown in Figure 7. Thus, the self-cleaning process can be significantly shortened with the system (100) of the present invention.

[0086] It can be seen from the description above that the system (100) of the present invention is capable of controlling a self-cleaning process in an indoor unit of an air conditioner by constantly tracking the condensate amount in a heat exchanger and monitoring the progress, ensuring a more efficient and effective completion of the self-cleaning process. As a result, the self-cleaning process in the present invention does not depend a pre-set or fixed duration, unlike the conventional self-cleaning methods that require thereof. Moreover, the system (100) of the present invention is capable of flexibly adjusting a duration of the self-cleaning process according to a plurality of indoor and outdoor conditions to ensure the self-cleaning process is operating at its optimal state. Consequently, the cleanliness of the indoor unit is maintained by effectively removing dust and dirt from the heat exchanger.Various modifications to these embodiments are apparent to those skilled in the art from the description and the accompanying drawings. The principles associated with the various embodiments described herein may be applied to other embodiments. Therefore, the description is not intended to be limited to the embodiments shown along with the accompanying drawings but is to be providing broadest scope of consistent with the principles and the novel features disclosed or suggested herein. Accordingly, the invention is anticipated to hold on to all other such alternatives, modifications, and variations that fall within the scope of the present invention and appended claims.

Claims

CLAIMS:

1. A system (100) for controlling self-cleaning process in an indoor unit of an air conditioner, comprising:a first sensor (101 ) for detecting an indoor ambient temperature;a second sensor (102) for detecting an indoor humidity;a third sensor (103) for detecting an outdoor ambient temperature, and a controller (104) for adjusting operation of the air conditioner to control the self-cleaning process;wherein the controller (104) is configured for receiving inputs including the detected indoor ambient temperature from the first sensor (101 ), the detected indoor humidity from the second sensor (102) and the detected outdoor ambient temperature from the third sensor (103) during a cooling operation of the air conditioner, processing the received inputs to determine a condensate amount generated in the indoor unit, subsequently comparing the condensate amount generated with a target condensate amount for the self-cleaning process; andwherein the controller (104) is configured for terminating the cooling operation once the condensate amount generated meets the target condensate amount.

2. The system (100) as claimed in claim 1, wherein the controller (104) constantly determining the condensate amount generated until the target condensate amount is met.

3. The system (100) as claimed in claim 1, wherein the controller (104) determining the condensate amount generated using the detected indoor ambient temperature, the detected indoor humidity and the detected outdoor ambient temperature via the equation of:CT= a + b (TID) + c (HID) + d (T0D) + e (Tm)2+ f (HID)2+ g(T0D)2+ h(TIDHID) + i (T / D)(TOD) + j (HID)(T0D+ k (TIDHID(T0DwhereCT denotes the condensate amount generated;TID denotes the detected indoor ambient temperature;HID denotes the detected indoor humidity;TOD denotes the detected outdoor ambient temperature; anda, b, c, d, e, f, g, h, i, j and k are constant values.

4. The system (100) as claimed in claim 1, wherein the controller (104) is configured for controlling an indoor fan (106) to operate at a pre-determined rotating speed according to the detected indoor humidity and directing an air outlet flap (107) towards a pre-determined angle during the cooling operation to generate sufficient condensate amount so as to meet the target condensate amount for the self-cleaning process.

5. The system (100) as claimed in claim 4, wherein the controller (104) controls the indoor fan (106) to operate at at least an intermediate speed during the cooling operation.

6. The system (100) as claimed in claim 4, wherein the pre-determined angle of the air outlet flap (107) is at least more than 5° from a fully closed position of the air outlet flap (107).

7. The system (100) as claimed in claim 1, wherein the controller (104) further switching to an operation for drying the indoor unit after terminating the cooling operation.

8. The system (100) as claimed in claim 7, wherein the controller (104) is configured for switching to the operation for drying the indoor unit by switching off a compressor (105), and setting any one or a combination of a rotating speed of an indoor fan (106) and an angle of an air outlet flap (107) to a fixed value for drying the indoor unit after ending the cooling operation.

9. The system (100) as claimed in claim 8, wherein the controller (104) sets the rotating speed of the indoor fan (106) to at least an intermediate speed for drying the indoor unit.

10. The system (100) as claimed in claim 8, wherein the controller (104) sets the angle of the air outlet flap (107) to at least more than 5°from a fully closed position of the air outlet flap (107).

11. The system (100) as claimed in claim 7, wherein the controller (104) is configured for determining a duration for drying the indoor unit using the detected indoor ambient temperature and the detected indoor humidity.

12. The system (100) as claimed in claim 11, wherein the controller (104) determining the duration for drying the indoor unit using the detected indoor ambient temperature and the detected indoor humidity via the equation of:TmD= a + b (TID) + c (HID) + d (Tm)2+ e (HID)2+ / (T / D)(tf / D)whereTmo denotes the duration for drying the indoor unit;TID denotes the detected indoor ambient temperature;HID denotes the detected indoor humidity; anda, b, c, d, e and f are constant values.

13. The system (100) as claimed in claim 1, wherein the target condensate amount is pre-determined based on a manufacturer’s predefined configuration setting.

14. The system (100) as claimed in claim 1, wherein the condensate is generated in a heat exchanger of the indoor unit.

15. The system (100) as claimed in claim 1, wherein the indoor ambient temperature is indoor dry bulb temperature.

16. The system (100) as claimed in claim 1, wherein the outdoor ambient temperature is outdoor dry bulb temperature.

17. The system (100) as claimed in claim 1, wherein the second sensor (102) is a relative humidity sensor for detecting relative humidity of an indoor environment.

18. The system (100) as claimed in claim 1, wherein the first sensor (101), the second sensor (102) and the third sensor (103) are existing sensors in the air conditioner.

19. The system (100) as claimed in claim 1, wherein the first sensor (101) and the second sensor (102) are integrated to become a single sensor.

20. The system (100) as claimed in claim 19, wherein the single sensor is an existing sensor in the air conditioner.

21. An air conditioner comprising an indoor unit with a system (100) according to any one of the preceding claims.

22. A method for controlling self-cleaning process in an indoor unit of an air conditioner, the method comprising:detecting an indoor ambient temperature using a first sensor (101); detecting an indoor humidity using a second sensor (102);detecting an outdoor ambient temperature using a third sensor (103); receiving inputs comprising the detected indoor ambient temperature, the detected indoor humidity and the detected outdoor ambient temperature during a cooling operation of the air conditioner from the first sensor (101), the second sensor (102) and the third sensor (103), by a controller (104); processing the received inputs to determine a condensate amount generated in the indoor unit, by the controller (104);comparing the condensate amount generated with a target condensate amount for the self-cleaning process, by the controller (104); and ending the cooling operation once the target amount of condensate is achieved, by the controller (104).

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