Defrosting control method, air conditioning unit and computer readable storage medium

Abstract

The application discloses a defrosting control method, an air conditioning unit and a computer readable storage medium, and the method comprises the following steps: operating the unit in a heating mode; obtaining a first temperature parameter detected by a first temperature sensing bulb located at the inlet of an outdoor heat exchanger; obtaining a second temperature parameter detected by a second temperature sensing bulb located at the outlet of the outdoor heat exchanger; when the first temperature parameter and the second temperature parameter are both within T0±a, a is a preset deviation value; recording the maintaining time length t of the first and second temperature sensing bulbs within T0±a, and correcting the normal defrosting target temperature according to the maintaining time length t after the maintaining time length t is obtained. The method actually divides the defrosting process into three stages, specifically including a starting stage, a cumulative frost formation stage and a frost deterioration stage, the time length of the cumulative frost formation stage is recorded, and the normal defrosting temperature is corrected according to the time length, so that the high energy consumption conditions of the air conditioner, such as no frost defrosting, heavy frost defrosting, poor heating effect and low energy efficiency, are avoided.

Description

Technical Field

[0001] This invention relates to the field of air conditioning defrosting technology, and in particular to a defrosting control method, an air conditioning unit, and a computer-readable storage medium. Background Technology

[0002] With the increasing popularity of heat pump air conditioners in winter, the outdoor heat exchanger involved in the heating process has attracted much attention. In this process, the outdoor heat exchanger acts as an evaporator, and when the outdoor temperature is low and there is a certain level of humidity, frost may form on the outdoor heat exchanger. Since frost formation can significantly impact user comfort, energy consumption, and the reliability of the heating process, addressing the frost problem has become an important and indispensable challenge.

[0003] The industry primarily employs temperature- and time-based defrosting control methods, considering only outdoor temperature, evaporator tube temperature, and heating operation time to determine frost conditions. However, this method does not adequately account for the impact of other environmental factors (such as ambient humidity) on the frost rate. Therefore, existing technologies are not accurate in frost assessment, potentially leading to two scenarios: either ineffective defrosting in frost-free conditions, resulting in energy waste; or failure to defrost promptly in cases of severe frost, leading to poor heating performance and reduced energy efficiency.

[0004] Addressing these issues, more precise assessment and handling of outdoor heat exchanger frosting during the heating process of heat pump air conditioners has become a significant challenge for improving system performance and user comfort. It is necessary to introduce more reliable control strategies to more accurately predict and manage frosting, optimize the defrosting process, and improve heating efficiency and energy utilization. Summary of the Invention

[0005] In order to solve the technical problem of inaccurate defrosting judgment in the prior art, the present invention proposes a defrosting control method, an air conditioning unit, and a computer-readable storage medium.

[0006] The technical solution adopted in this invention is:

[0007] This invention proposes a defrosting control method, which includes the following steps:

[0008] Unit operation heating mode;

[0009] Acquire a first temperature parameter detected by a first temperature sensor located at the inlet of the outdoor heat exchanger; and acquire a second temperature parameter detected by a second temperature sensor located at the outlet of the outdoor heat exchanger.

[0010] When the first temperature parameter detected by the first temperature sensor and the second temperature parameter detected by the second temperature sensor are both within T0±a, a is a preset deviation value, and timing begins.

[0011] When the temperature parameters detected by the first temperature sensor or by both the first and second temperature sensors deviate from the range of T0±a, stop timing and obtain the duration t.

[0012] The target temperature for regular defrosting is adjusted based on the duration t.

[0013] Specifically, adjusting the target temperature for normal defrosting based on the duration t includes: selecting a corresponding adjustment value T based on the preset duration range in which the duration t is located to adjust the target temperature for normal defrosting.

[0014] Furthermore, the shorter the duration t, the larger the corresponding correction value T.

[0015] Furthermore, when the duration t is within the preset normal duration range, Trepair = 0.

[0016] Furthermore, when the maintenance duration t is greater than the maximum value of the normal duration range, the value range of T_repair is -2 to -4℃.

[0017] Preferably, the normal duration ranges from 50 to 120 minutes.

[0018] After correcting the conventional defrosting target temperature, when the first temperature parameter detected by the first temperature sensor is less than or equal to the corrected conventional defrosting target temperature and is maintained for a first preset time, the unit operates in defrosting mode.

[0019] The present invention also proposes an air conditioning unit that uses the above-mentioned defrosting control method to correct the conventional defrosting target temperature for defrosting the outdoor heat exchanger.

[0020] Preferably, the air conditioning unit is a heat pump air conditioning unit.

[0021] The present invention also proposes a computer-readable storage medium for storing a computer program, which executes the above-described defrosting control method when running.

[0022] Compared with existing technologies, the method proposed in this invention actually divides the defrosting process into three stages: the start-up stage, the cumulative frost stage, and the frost deterioration stage. By recording the duration of the cumulative frost stage, the actual frost situation of the outdoor heat exchanger is determined, and the conventional defrosting temperature is corrected based on this duration. Factors such as ambient humidity are also incorporated, which makes up for the shortcomings of existing technologies in frost control and avoids high energy consumption of air conditioners such as no-frost defrosting or heavy frost that does not defrost, poor heating effect, and low energy efficiency. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a flowchart from an embodiment of the present invention;

[0025] Figure 2 This is a flowchart of a specific embodiment of the present invention;

[0026] Figure 3 This is a piping structure diagram of the air conditioning unit in an embodiment of the present invention;

[0027] 1. Compressor;

[0028] 2. Four-way valve;

[0029] 3. Outdoor heat exchanger;

[0030] 31. First sensing bulb;

[0031] 32. Second temperature sensing bag;

[0032] 4. Electronic expansion valve;

[0033] 51. Large valve;

[0034] 52. Small valves;

[0035] 6. Outdoor unit. Detailed Implementation

[0036] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0037] The principles and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0038] The industry primarily employs temperature- and time-based defrosting control methods, considering only outdoor temperature, evaporator tube temperature, and heating operation time to determine frost conditions. However, this method does not adequately account for the impact of ambient humidity differences on the frost rate. Therefore, existing technologies are inaccurate in frost detection, potentially leading to two scenarios: either ineffective defrosting in frost-free conditions, resulting in energy waste; or failure to defrost promptly in cases of severe frost, leading to poor heating performance and reduced energy efficiency.

[0039] To address these issues, more precise judgment and handling of outdoor heat exchanger frosting during the heating process of heat pump air conditioners has become a significant challenge for improving system performance and user comfort. It is necessary to introduce a more comprehensive control strategy that takes into account factors such as ambient humidity, thereby more accurately predicting and managing frosting conditions, optimizing the defrosting process, and improving heating efficiency and energy utilization. To this end, this invention proposes a more comprehensive defrosting control method that considers factors such as ambient humidity to more accurately predict and manage frosting conditions, thereby optimizing the defrosting process and improving heating efficiency and energy utilization. This method divides the defrosting process into three stages: the start-up stage, the accumulated frosting stage, and the frosting deterioration stage.

[0040] like Figure 1 As shown, this invention proposes a defrosting control method, specifically applied to a heat pump air conditioner. The heat pump air conditioner includes an outdoor heat exchanger located outdoors. When the heat pump air conditioner is operating in heating mode, a first temperature sensor at the inlet of the outdoor heat exchanger detects a first temperature parameter, and a second temperature parameter is detected at the outlet of the outdoor heat exchanger. The defrosting control method of the heat pump air conditioner specifically includes the following steps:

[0041] Heating mode of heat pump air conditioning unit operation;

[0042] The system acquires the first temperature parameter detected by the first temperature sensor at the inlet of the outdoor heat exchanger in real time; and acquires the second temperature parameter detected by the second temperature sensor at the outlet of the outdoor heat exchanger.

[0043] When the first temperature parameter detected by the first temperature sensor and the second temperature parameter detected by the second temperature sensor are both within T0±a, where a is a preset deviation value, timing begins; when the temperature parameters detected by the first temperature sensor and the second temperature sensor (or only the first temperature sensor) both deviate from the range of T0±a, timing stops and the duration t is obtained, which is the duration for which the temperature parameters detected by the first temperature sensor and the second temperature sensor are maintained within T0±a; then the target temperature for normal defrosting is adjusted according to the duration t.

[0044] The target temperature for conventional defrosting is corrected based on the duration t. The duration t measures the system's operating time during the frost accumulation phase, thus providing a more accurate assessment of the frost situation.

[0045] Through the above steps, the defrosting control method of this invention can more accurately determine the frosting situation based on the temperature changes of the outdoor heat exchanger and perform defrosting operations according to the actual situation, thereby improving heating effect and energy utilization efficiency. At the same time, this method also effectively incorporates factors such as ambient humidity, thus overcoming the shortcomings of existing technologies in frosting control.

[0046] By simultaneously acquiring the duration for which the temperature parameters detected by the first and second temperature sensors are maintained within T0±a, the acquisition of the maintenance time t is not affected when the temperature of one of the first and second temperature sensors fluctuates due to system operation, because the timing ends only when both the first and second temperature sensors deviate from the temperature range, thus improving the accuracy of the recording.

[0047] Based on the study of unit frosting, the frosting process is divided into three stages: the start-up stage, the relatively stable cumulative frosting stage, and the frosting deterioration stage. The following provides a detailed explanation and examples of these three stages.

[0048] Start-up phase:

[0049] The start-up phase specifically refers to the initial heating phase, where the refrigerant in the cooling system circulates and establishes a pressure differential. This process is characterized by a rapid drop in the outdoor unit's pipe temperature, bringing the unit to the frosting condition, typically within 3 to 10 minutes.

[0050] Accumulated frost stage:

[0051] When the first temperature parameter detected by the first temperature sensor is within the preset deviation value a within the temperature range T0±a, and the second temperature parameter detected by the second temperature sensor is also within the preset deviation value a within the temperature range T0±a, meaning the pipe temperature will also reach T0±a, the inlet and outlet temperatures of the outdoor heat exchanger enter a relatively stable frosting accumulation stage. This process is characterized by the frost on the outdoor unit condenser gradually thickening, but the pipe temperature slowly decreasing. This process is affected by outdoor humidity and differences in the unit itself, and generally accounts for a large part of the entire frosting cycle.

[0052] Frosting worsening stage:

[0053] As the frost thickens, the heat exchange of the outdoor condenser deteriorates, causing the outdoor unit's pipe temperature to drop rapidly. This is the deterioration phase. After running for a period of time, the pipe temperature drops rapidly, and the heating capacity is generally 50-60% of the initial stable phase. At this point, it is considered that the unit should enter the defrosting phase.

[0054] Specifically, the control logic corresponding to this invention is as follows:

[0055] When the air conditioner is turned on in heating mode, the unit starts up according to the normal heating operation logic. However, after the compressor starts, it begins to monitor the real-time pipe temperature of the first and second temperature sensors. After running for a period of time, the pipe temperature detected by the first temperature sensor will drop rapidly to T0. This is the heating start-up phase of the unit, and the entire system is not yet stable. The temperature detected by the second temperature sensor will lag behind the first temperature sensor in decreasing, and eventually the detected pipe temperature will also reach T0 (the actual temperature of the temperature sensors will fluctuate, but it is generally considered stable if the change is within 0.5 degrees, i.e., a = 0.5). At this time, the unit enters a relatively stable frosting accumulation phase.

[0056] The first and second temperature sensors will maintain the temperature at T0 for a period of time. After that, the tube temperature detected by the first temperature sensor will decrease (and the second temperature sensor will also decrease). The time during which the tube temperature detected by the first and second temperature sensors remains at T0 is recorded as t. The defrosting tube temperature is then corrected based on t. Generally, the shorter t is, the faster the frosting rate, and the higher the air humidity at this time.

[0057] In a specific embodiment, when it is necessary to correct the target temperature for conventional defrosting based on the duration t, the specific steps are as follows:

[0058] First, the duration 't' is compared to preset duration ranges, which represent different defrosting conditions such as light, moderate, and heavy frosting. Based on the preset duration range within which the duration 't' falls, the corresponding correction value 'T' is selected. 修 This correction value can be preset and has different values ​​within different preset duration ranges.

[0059] Select the correction value T 修 This is added to the standard defrosting target temperature to obtain the corrected target temperature. The corrected target temperature will more accurately reflect the current frosting condition, facilitating on-demand defrosting operations.

[0060] By following the steps above and correcting the target defrosting temperature based on the duration t, the defrosting control strategy can be adjusted more precisely to adapt to different frost conditions. This correction process better ensures heating performance and energy efficiency while also taking into account the influence of factors such as ambient humidity. Overall, the defrosting control method of this invention comprehensively considers multiple factors, enabling the system to more intelligently judge and handle frost conditions, achieving a more optimized defrosting effect.

[0061] Specifically, the shorter the duration t, the higher the corresponding correction value T. 修 The larger the value, the more severe the actual frosting, requiring a larger correction value. Additionally, there is a normal duration range within the preset duration range; when the duration t is within the preset normal duration range, T... 修 =0, meaning this duration is within the normal range and does not require adjustment to the standard defrosting target temperature T. 化 Adjustments will be made.

[0062] The following table provides specific examples of preset duration ranges:

[0063]

[0064] The specific explanation based on the table above is as follows:

[0065] The normal preset duration range is 50–120 minutes, and when the duration t is within this range, T 修 =0, meaning no adjustment is made to the target temperature for normal defrosting.

[0066] The first preset duration range is less than 30 minutes, and the duration t is maintained within this range. 修 =2℃, which means increasing the normal defrosting target temperature by 2 degrees. At this time, the external humidity is high, and it is necessary to increase the defrosting sensitivity to perform defrosting.

[0067] The second preset duration range is greater than or equal to 30 minutes and less than 50 minutes. When the duration t is within this range, T... 修 =1℃, which means increasing the standard defrosting target temperature by 1 degree. At this time, the ambient humidity is high, and it is also necessary to increase the defrosting sensitivity for defrosting.

[0068] The third preset duration range is greater than 120 minutes, and when the duration t is within this range, T... 修 = -3℃, which means lowering the normal defrosting target temperature by 3 degrees. At this temperature, the outside humidity is low, and the outdoor heat exchanger frosts slowly. Therefore, it is necessary to reduce the defrosting sensitivity to improve the actual operating efficiency of the unit.

[0069] Standard defrosting target tube temperature T 化 This is based on experimental testing and is generally related to the outdoor ambient temperature. (This is a commonly used method in the industry for determining defrosting, and will not be elaborated upon further.)

[0070] The defrosting control method also includes the following steps: after correcting the conventional defrosting target temperature, when the first temperature parameter detected by the first temperature sensor is less than or equal to the corrected conventional defrosting target temperature and is maintained for a first preset time, the unit runs the defrosting mode to defrost.

[0071] In a specific embodiment, when the first temperature parameter T1 detected by the first temperature sensor is ≤ (T 化 +T 修 And maintain this for 3 minutes, then the unit will begin executing the defrosting command. For example, at an outer ambient temperature of 7 degrees Celsius, T 化 The temperature is set to -2℃. If the unit operates for about 40 minutes, and the first temperature parameter T1 detected by the first temperature sensor is lower than T0, and T1 ≤ -1℃ for more than 3 minutes, the unit will perform defrosting.

[0072] The present invention also proposes an air conditioning unit that uses the above-mentioned defrosting control method to correct the conventional defrosting target temperature for defrosting the outdoor heat exchanger.

[0073] The air conditioning unit is specifically a heat pump air conditioning unit, which includes an indoor unit and an outdoor unit.

[0074] The outdoor unit 6 specifically includes: a large valve 51, a small valve 52, a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an electronic expansion valve 4, and a fan corresponding to the outdoor heat exchanger 3. Specifically, the left pipe of the outdoor heat exchanger 3 is equipped with a first temperature sensing bulb 31, and the right pipe is equipped with a second temperature sensing bulb 32. When the air conditioning unit is running in heating mode, the refrigerant enters the outdoor heat exchanger from the left side and then flows from the right side of the outdoor heat exchanger. That is, the first temperature sensing bulb detects the inlet temperature of the outdoor heat exchanger in heating mode, and the second temperature sensing bulb detects the outlet temperature of the outdoor heat exchanger in heating mode.

[0075] In a specific embodiment, the second temperature sensor 32 is set at the last small bend of the circuit with the highest temperature among all the circuits during heating, or at the inlet of the outdoor heat exchanger, as a defrosting auxiliary temperature sensor.

[0076] The present invention also proposes a computer-readable storage medium for storing a computer program that executes the above-described defrosting control method when the computer program is run.

[0077] The method proposed in this invention divides the defrosting process into three stages: the start-up stage, the cumulative frost stage, and the frost deterioration stage. By recording the duration of the cumulative frost stage, the actual frost condition of the outdoor heat exchanger is determined, and the conventional defrosting temperature is corrected based on this duration. Factors such as ambient humidity are also incorporated, which makes up for the shortcomings of existing technologies in frost control and avoids high energy consumption of air conditioners, such as no-frost defrosting or heavy frost that does not defrost, poor heating effect, and low energy efficiency.

[0078] In one or more exemplary embodiments, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functionality may be stored or transmitted as one or more instructions or code on or through a computer-readable medium. A computer-readable medium includes both computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. A storage medium may be any available medium accessible to a computer. By way of example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible to a computer. Any connection is also legitimately referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of a medium. As used in this article, disk and disc include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), floppy disks, and Blu-ray discs. Disks typically reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of these should also be included within the scope of computer-readable media.

[0079] It should be noted that the terminology used above is for describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0080] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0081] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0082] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0083] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0084] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A defrosting control method, characterized in that, Including the following steps: Unit operation heating mode; Acquire a first temperature parameter detected by a first temperature sensor located at the inlet of the outdoor heat exchanger; and acquire a second temperature parameter detected by a second temperature sensor located at the outlet of the outdoor heat exchanger. When the first temperature parameter detected by the first temperature sensor and the second temperature parameter detected by the second temperature sensor are both within T0±a, where a is a preset deviation value, timing begins; when the temperature parameter detected by the first temperature sensor deviates from the range of T0±a, or when both the temperature parameter detected by the first temperature sensor and the temperature parameter detected by the second temperature sensor deviate from the range of T0±a, timing stops and the duration t is obtained, and the target temperature for normal defrosting is corrected according to the duration t.

2. The defrosting control method as described in claim 1, characterized in that, The step of adjusting the target temperature for conventional defrosting based on the maintenance duration t specifically includes: selecting a corresponding correction value T based on the preset duration range in which the maintenance duration t falls. 修 Corrected the target temperature for normal defrosting.

3. The defrosting control method as described in claim 2, characterized in that, The shorter the duration t, the corresponding correction value T 修 The larger.

4. The defrosting control method as described in claim 2, characterized in that, When the duration t is within the preset normal duration range, T 修 =0.

5. The defrosting control method as described in claim 4, characterized in that, When the duration t is greater than the maximum value of the normal duration range, T 修 The value range is -2 to -4℃.

6. The defrosting control method as described in claim 4, characterized in that, The normal duration is between 50 and 120 minutes.

7. The defrosting control method as described in claim 1, characterized in that, After correcting the conventional defrosting target temperature, when the first temperature parameter detected by the first temperature sensor is less than or equal to the corrected conventional defrosting target temperature and is maintained for a first preset time, the unit operates in defrosting mode.

8. An air conditioning unit, characterized in that, The defrosting control method according to any one of claims 1 to 7 is used to modify the conventional defrosting target temperature for defrosting outdoor heat exchangers.

9. The air conditioning unit as described in claim 8, characterized in that, The air conditioning unit is a heat pump air conditioning unit.

10. A computer-readable storage medium for storing a computer program, characterized in that, The computer program executes the defrosting control method according to any one of claims 1 to 7 when it runs.

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