Control method and device of air conditioner and air conditioning system

Abstract

The invention relates to the technical field of air conditioners, and provides a control method and device of an air conditioner and an air conditioning system.The control method comprises the steps that under the condition that the air conditioner is started and is in a heating mode, the operation duration of a compressor, the current outdoor environment temperature and the current outdoor coil pipe temperature are obtained; under the condition that the operation duration is smaller than the first preset duration, whether the outdoor heat exchanger is frozen or not is judged based on the current outdoor environment temperature and the current outdoor coil pipe temperature; and under the condition that the outdoor heat exchanger is frozen, the air conditioner is controlled to enter a defrosting mode. According to the method, the running duration of the compressor, the current outdoor environment temperature and the current outdoor coil pipe temperature are comprehensively judged when heating is started, and whether the surface of the outdoor heat exchanger is frozen or not can be effectively recognized; and when it is confirmed that freezing exists, the air conditioner preferentially executes defrosting operation, the situation that when the surface of the outdoor heat exchanger is in the frozen state, the outdoor heat exchanger directly enters the heating operation, and consequently the invalid heating stage is caused is avoided, and therefore the heating efficiency and the use experience are improved.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to a control method, device and air conditioning system for an air conditioner. Background Technology

[0002] During the heating operation of an air conditioner, the outdoor heat exchanger exchanges heat by absorbing heat from the environment, causing its surface temperature to drop. When the surface temperature of the heat exchanger is lower than the air dew point temperature and the ambient humidity is high, moisture in the air will condense on its surface, forming a frost layer. As the frost layer accumulates, the heat exchange efficiency decreases significantly, affecting the normal heating performance of the air conditioner.

[0003] Currently, air conditioners generally use a fixed threshold control strategy based on outdoor coil temperature and running time to initiate the defrost program. For example, when the air conditioner has been running continuously in heating mode for 45 to 60 minutes, or when the outdoor coil temperature is detected to be below -5°C, the system will automatically enter defrost mode.

[0004] However, in the rainy and snowy weather of winter in the south, when the outdoor unit of the air conditioner starts heating, it is easy to cause low heat exchange efficiency and the compressor is forced to operate in an inefficient condition, resulting in energy waste and significantly reducing the heating effect and comfort of users in actual use. Summary of the Invention

[0005] This invention provides a control method, device, and air conditioning system for an air conditioner, which solves the defects of low heating efficiency and poor user comfort during heating start-up in the prior art. By judging the icing before start-up, it effectively avoids the ineffective heating stage and improves heating efficiency and user experience.

[0006] This invention provides a control method for an air conditioner, comprising: When the air conditioner is turned on and in heating mode, obtain the compressor's running time, the current outdoor ambient temperature, and the current outdoor coil temperature. If the running time is less than the first preset time, it is determined whether the outdoor heat exchanger is icing based on the current outdoor ambient temperature and the current outdoor coil temperature. When the outdoor heat exchanger is frozen, the air conditioner is controlled to enter defrost mode.

[0007] According to a control method for an air conditioner provided by the present invention, determining whether the outdoor heat exchanger is icing based on the current outdoor ambient temperature and the current outdoor coil temperature includes: Compare the current outdoor ambient temperature with the current outdoor coil temperature; If the current outdoor ambient temperature is less than a first temperature threshold, the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature is greater than or equal to a second temperature threshold, and the current outdoor coil temperature is less than or equal to a third temperature threshold, it is determined that the outdoor heat exchanger is icing; wherein the second temperature threshold is greater than the first temperature threshold, and the third temperature threshold is less than the first temperature threshold.

[0008] According to a control method for an air conditioner provided by the present invention, the method further includes: If the running time is greater than or equal to the first preset time, it is determined whether the outdoor heat exchanger is frosted based on the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature and / or the cooling rate of the current outdoor coil temperature. When the outdoor heat exchanger is frosted, the air conditioner is controlled to enter defrost mode.

[0009] According to a control method for an air conditioner provided by the present invention, determining whether the outdoor heat exchanger is frosted based on the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature includes: Compare the current outdoor ambient temperature with the current outdoor coil temperature; If the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature is greater than or equal to a fourth temperature threshold, it is determined that the outdoor heat exchanger is frosted; wherein the fourth temperature threshold is less than the second temperature threshold.

[0010] According to a control method for an air conditioner provided by the present invention, determining whether the outdoor heat exchanger is frosted based on the cooling rate of the current outdoor coil temperature includes: Determine the cooling rate of the current outdoor coil temperature; If the cooling rate is greater than a preset rate threshold, it is determined that the outdoor heat exchanger is frosted.

[0011] According to a control method for an air conditioner provided by the present invention, before determining whether the outdoor heat exchanger is icing based on the current outdoor ambient temperature and the current outdoor coil temperature, the method further includes: If the current outdoor ambient temperature is greater than zero, it is determined that the air conditioner does not need to enter defrost mode.

[0012] According to a control method for an air conditioner provided by the present invention, after controlling the air conditioner to enter the defrost mode, the method further includes: Get defrost duration; If the defrosting time exceeds the second preset time, the temperature threshold corresponding to the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature is reduced.

[0013] According to a control method for an air conditioner provided by the present invention, obtaining the defrosting duration includes: If the current outdoor coil temperature is greater than or equal to a fifth temperature threshold, the defrosting duration is obtained; wherein the fifth temperature is greater than the first temperature threshold.

[0014] The present invention also provides a control device for an air conditioner, comprising the following modules: The acquisition module is used to acquire the compressor's running time, the current outdoor ambient temperature, and the current outdoor coil temperature when the air conditioner is turned on and in heating mode. The first judgment module is used to determine whether the outdoor heat exchanger is icing up, based on the current outdoor ambient temperature and the current outdoor coil temperature, when the running time is less than the first preset time. The first control module is used to control the air conditioner to enter defrost mode when the outdoor heat exchanger is frozen.

[0015] The present invention also provides an air conditioning system, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the control method of any of the above-described air conditioners.

[0016] The air conditioner control method provided by this invention can effectively identify whether the surface of the outdoor heat exchanger is icy by comprehensively judging the compressor running time, the current outdoor ambient temperature, and the current outdoor coil temperature when heating is started. If icing is confirmed, the air conditioner will prioritize defrosting to avoid entering the ineffective heating stage directly when the outdoor heat exchanger surface is icy, thereby improving the heating efficiency of the air conditioner and enhancing the user experience in low temperature and high humidity environments. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is one of the flowcharts illustrating the control method for an air conditioner provided by the present invention.

[0019] Figure 2 This is the second flowchart illustrating the control method for an air conditioner provided by the present invention.

[0020] Figure 3This is the third flowchart illustrating the control method for an air conditioner provided by the present invention.

[0021] Figure 4 This is the fourth flowchart illustrating the control method for an air conditioner provided by the present invention.

[0022] Figure 5 This is the fifth flowchart illustrating the control method for an air conditioner provided by the present invention.

[0023] Figure 6 This is the sixth flowchart illustrating the control method for an air conditioner provided by the present invention.

[0024] Figure 7 This is a schematic diagram of the control device for the air conditioner provided by the present invention.

[0025] Figure 8 This is a schematic diagram of the air conditioning system provided by the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0027] The following is combined Figures 1-6 The present invention describes a control method for an air conditioner.

[0028] Embodiments of the present invention provide a control method for an air conditioner, such as... Figure 1 As shown, the method includes the following steps: Step 100: With the air conditioner turned on and in heating mode, obtain the compressor's running time, the current outdoor ambient temperature, and the current outdoor coil temperature.

[0029] Step 200: If the running time is less than the first preset time, determine whether the outdoor heat exchanger is icing based on the current outdoor ambient temperature and the current outdoor coil temperature.

[0030] Step 300: If the outdoor heat exchanger is frozen, control the air conditioner to enter defrost mode.

[0031] Understandably, when the air conditioner is turned on and in heating mode, the system first obtains the compressor's running time, the current outdoor ambient temperature, and the current outdoor coil temperature. When the compressor's running time is less than a first preset time, it determines whether the outdoor heat exchanger is in an icing state based on the difference between the current outdoor ambient temperature and the current outdoor coil temperature. If the determination result is that the outdoor heat exchanger (outdoor coil) is icing, the air conditioner does not immediately enter heating mode, but instead prioritizes entering defrosting mode to eliminate frost on the surface of the outdoor heat exchanger, avoid the generation of ineffective heating stages, and thus improve the system's heating efficiency and user comfort.

[0032] It should be noted that in the rainy and snowy weather of southern winters, the fins of air conditioner outdoor units may freeze due to the low temperature and high humidity environment when the unit is off. Traditional methods cannot identify this initial icing state during startup. If ice already exists on the surface of the outdoor heat exchanger before startup, and the unit still enters heating mode directly, the air conditioner will operate at low frequency for a long time without defrosting, thus affecting the heating power and coefficient of performance. If the air conditioner reaches defrosting conditions but the frost layer is thick, the defrosting time will be too long, resulting in a large drop in indoor temperature, both of which will affect the comfort of the indoor environment and the user's heating comfort experience. This invention effectively identifies the icing condition on the surface of the outdoor heat exchanger, avoiding the ineffective heating stage of continuing to operate when the unit is already frozen before startup.

[0033] The air conditioner control method provided in this embodiment of the invention can effectively identify whether the surface of the outdoor heat exchanger is icy by comprehensively judging the compressor running time, the current outdoor ambient temperature and the current outdoor coil temperature when heating is started; and if icing is confirmed, the air conditioner will prioritize defrosting operation to avoid entering the ineffective heating stage directly when the outdoor heat exchanger surface is icy, thereby improving the heating efficiency of the air conditioner and improving the user experience in low temperature and high humidity environments.

[0034] According to an embodiment of the present invention, step 100 may specifically include the following: When the air conditioner is turned on and running in heating mode, the compressor's running time is obtained in real time and recorded as the compressor's running time t; the outdoor ambient temperature of the air conditioner is obtained and recorded as the current outdoor ambient temperature Tao; and the outdoor coil temperature of the air conditioner is obtained and recorded as the current outdoor coil temperature Te.

[0035] Optional, such as Figure 2 As shown, in step 200, based on the current outdoor ambient temperature and the current outdoor coil temperature, it is determined whether the outdoor heat exchanger is icing. This can specifically include the following steps: Step 210: Compare the current outdoor ambient temperature with the current outdoor coil temperature.

[0036] Step 220: If the current outdoor ambient temperature is less than the first temperature threshold, the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature is greater than or equal to the second temperature threshold, and the current outdoor coil temperature is less than or equal to the third temperature threshold, determine that the outdoor heat exchanger is icing.

[0037] The second temperature threshold is greater than the first temperature threshold, and the third temperature threshold is less than the first temperature threshold.

[0038] Understandably, the system obtains the current outdoor ambient temperature and the current outdoor coil temperature, and calculates the temperature difference between them. It then determines the following three conditions: Condition 1: Is the current outdoor ambient temperature less than a first temperature threshold? Condition 2: Is the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature greater than or equal to a second temperature threshold? Condition 3: Is the current outdoor coil temperature less than or equal to a third temperature threshold? When all three conditions are met, it is determined that the surface of the outdoor coil has frozen, i.e., the fins have initial freezing, thereby triggering the corresponding defrosting control logic to control the air conditioner to enter defrosting mode.

[0039] For example, the first preset duration is denoted as t1, the first temperature threshold is denoted as T1, and the first temperature threshold T1 is less than or equal to 0℃; the second temperature threshold is denoted as T2, the third temperature threshold is denoted as T3, and the third temperature threshold T3 is less than 0℃; the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature is denoted as ΔT. If the continuous running time t of the air conditioner in heating mode is less than t1, and if the following conditions are met: Tao < T1 and ΔT ≥ T2 and Te ≤ T3, then it is determined that the outdoor heat exchanger has initial freezing. The air conditioner is then controlled to skip the normal heating mode and directly enter the defrost mode to effectively defrost the outdoor heat exchanger, thereby avoiding the ineffective heating stage and improving the system heating efficiency.

[0040] In this embodiment, the first preset duration t1 is 10 minutes, the first temperature threshold T1 is 0°C, the second temperature threshold T2 is 10°C, and the third temperature threshold T3 is -20°C. It should be noted that an outdoor ambient temperature < 0°C is the frosting / icing temperature. Simultaneously, if the outdoor coil temperature is too low, and the temperature difference between the outdoor ambient temperature and the outdoor coil temperature is significant, and the operating time is less than 10 minutes, it indicates that icing / frost has already occurred on the outdoor unit before startup.

[0041] In one embodiment of the present invention, such as Figure 3 As shown, the method further includes the following steps: Step 400: When the running time is greater than or equal to the first preset time, determine whether the outdoor heat exchanger is frosted based on the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature and / or the cooling rate of the current outdoor coil temperature.

[0042] Step 500: When the outdoor heat exchanger is frosted, control the air conditioner to enter defrost mode.

[0043] Understandably, during air conditioner operation, when the compressor's operating time is greater than or equal to the first preset duration, the frost status of the outdoor heat exchanger is assessed. Specifically, the assessment can be based on the temperature difference between the current outdoor ambient temperature and the outdoor coil temperature, or the cooling rate of the outdoor coil temperature. Alternatively, both the temperature difference between the current outdoor ambient temperature and the outdoor coil temperature and the cooling rate of the outdoor coil temperature can be used as assessment criteria. If the assessment result indicates that the outdoor heat exchanger (outdoor coil) is frosted, the air conditioner is controlled to enter defrost mode to melt the frost layer on the surface of the outdoor heat exchanger, ensuring heating efficiency and improving the user experience.

[0044] Optionally, in step 400, based on the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature, it is determined whether the outdoor heat exchanger is frosted. Specifically, this may include the following: Compare the current outdoor ambient temperature with the current outdoor coil temperature; If the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature is greater than or equal to the fourth temperature threshold, it is determined that the outdoor heat exchanger is frosted; where the fourth temperature threshold is less than the second temperature threshold.

[0045] It is understandable that obtaining the current outdoor ambient temperature and the current outdoor coil temperature, and calculating the temperature difference between the two, is one of the bases for determining whether the outdoor heat exchanger is frosted. Specifically, when the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature is detected to be greater than or equal to the fourth temperature threshold, it is determined that a frost layer has formed on the surface of the outdoor heat exchanger.

[0046] The fourth temperature threshold is set lower than the second temperature threshold used to determine whether there is an initial icing state before power-on, thereby adopting a more refined judgment standard in different operating stages and improving the accuracy of the system in identifying the frost state.

[0047] Optionally, in step 400, based on the cooling rate of the current outdoor coil temperature, it is determined whether the outdoor heat exchanger is frosted. This may specifically include the following: Determine the cooling rate of the current outdoor coil temperature; If the cooling rate exceeds a preset threshold, the outdoor heat exchanger is determined to be frosted.

[0048] Understandably, by monitoring the real-time temperature change trend of the outdoor coil and calculating its cooling rate, this is used as one of the criteria for determining whether the outdoor heat exchanger is frosted. Specifically, when the cooling rate of the outdoor coil exceeds a preset threshold, it indicates that frost has accumulated on the surface of the outdoor heat exchanger, leading to a decrease in heat exchange efficiency. At this point, the outdoor heat exchanger is determined to be in a frosted state, and subsequent defrosting operations need to be triggered. It should be noted that the method of judgment based on the cooling rate can effectively reflect the dynamic changes of the frost layer on the surface of the outdoor heat exchanger during operation, improving the timeliness and accuracy of defrosting control.

[0049] According to an embodiment of the present invention, step 400 may specifically include the following: When the running time is greater than or equal to the first preset time, based on the current outdoor ambient temperature and the current outdoor coil temperature, the following two conditions are determined: First condition: whether the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature is greater than or equal to the fourth temperature threshold; Second condition: whether the cooling rate of the current outdoor coil temperature is greater than the preset rate threshold; When either of the above conditions is met, it is determined that the surface of the outdoor heat exchanger has been frosted, thereby triggering the corresponding defrosting control logic to control the air conditioner to enter the defrosting mode.

[0050] For example, the fourth temperature threshold is denoted as T4, the current outdoor coil temperature cooling rate is denoted as dTe / dt, and the preset rate threshold is denoted as α, in °C / min (degrees per minute). If the air conditioner runs continuously in heating mode for more than t1, and if ΔT ≥ T4 or dTe / dt > α, it is determined that there is frost on the surface of the outdoor heat exchanger. The air conditioner is then controlled to enter defrost mode to effectively defrost the outdoor heat exchanger and improve the system's heating efficiency.

[0051] In this embodiment, the fourth temperature threshold T4 is 8℃, and the preset rate threshold α is 1℃ / min. It should be noted that in other embodiments, the fourth temperature threshold and the preset rate threshold can be set and optimized based on the actual operating conditions of the air conditioner, historical frosting data, and the environmental characteristics of different climate regions. For example, in low-temperature and high-humidity environments, the fourth temperature threshold and the preset rate threshold can be appropriately lowered to improve the sensitivity of frosting detection; while in areas with low humidity or high temperature, the fourth temperature threshold and the preset rate threshold can be appropriately increased to avoid false judgments. Furthermore, the fourth temperature threshold and the preset rate threshold can also be calibrated through experimental testing, simulation analysis, or big data learning to ensure that the judgment logic has good adaptability and accuracy in different application scenarios.

[0052] Furthermore, the two judgment conditions in step 400 also include a duration judgment, and the two judgment conditions are as follows: The first condition is whether the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature is greater than or equal to the fourth temperature threshold, and whether this difference persists for the first duration.

[0053] The second condition is whether the current outdoor coil temperature cooling rate is greater than the preset rate threshold and continues for a second duration.

[0054] In this embodiment, the first duration is 5 minutes and the second duration is 3 minutes. If the continuous heating operation time of the air conditioner exceeds t1, and if ΔT ≥ 8℃ for 5 minutes or dTe / dt > 1℃ / min for 3 minutes, then it is determined that frost has formed on the surface of the outdoor heat exchanger, and the air conditioner is controlled to enter defrost mode. It should be noted that a larger ΔT indicates a thicker frost layer on the surface of the outdoor heat exchanger; a larger outdoor coil temperature drop rate dTe / dt indicates a faster coil temperature drop and a faster frost layer growth rate.

[0055] In one embodiment of the present invention, such as Figure 4 As shown, before performing step 200, the method further includes the following steps: Step 600: If the current outdoor ambient temperature is greater than zero, determine that the air conditioner does not need to enter defrost mode.

[0056] Understandably, when the current outdoor ambient temperature is detected to be higher than 0℃, it is determined that the ambient temperature is high and the conditions for icing are not met. Therefore, there is no need to execute the icing judgment logic. In this case, the air conditioner will directly turn on and enter the heating mode. In the initial stage of operation, i.e. the first preset time, it will not judge whether the outdoor heat exchanger is icing. This avoids unnecessary operation caused by misjudgment in non-low temperature environments, reduces unnecessary energy consumption and operation interruption, and further improves the system operating efficiency.

[0057] In one embodiment of the present invention, such as Figure 5 As shown, after performing step 300, the method further includes the following steps: Step 700: Obtain the defrosting time.

[0058] It is understandable that the air conditioner is controlled to enter defrost mode, and the outdoor heat exchanger is defrosted by heating it or other defrosting methods; after the defrosting process is completed, the duration of this defrosting process is obtained and recorded as the defrosting duration.

[0059] Step 800: If the defrosting time exceeds the second preset time, reduce the temperature threshold corresponding to the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature.

[0060] Understandably, if the defrosting time exceeds the second preset time, it indicates that the current defrosting operation is prolonged, requiring continuous heating of the outdoor heat exchanger to melt the frost layer, thus consuming more electrical energy or increasing the workload of the compressor, leading to unnecessary energy consumption increases. Furthermore, excessively long defrosting times can reduce the overall system operating efficiency, as the air conditioner cannot perform heating operations normally during this period, reducing user comfort. Based on this, this embodiment lowers the temperature threshold used to determine whether the outdoor heat exchanger is frosted or icy when the defrosting time exceeds the second preset time. This temperature threshold corresponds to the difference between the current outdoor ambient temperature and the outdoor coil temperature. By lowering this temperature threshold, the system can identify frosting or icing conditions earlier, avoiding energy waste and system efficiency reduction caused by excessively long defrosting times, thereby achieving an efficient defrosting control process.

[0061] For example, during the heating operation of the air conditioner, if the running time is less than a first preset time, the current outdoor ambient temperature and outdoor coil temperature are acquired in real time, and it is determined whether the outdoor heat exchanger has iced up. If the determination result is that icing has occurred, the air conditioner is controlled to enter defrost mode; after defrosting is completed, the air conditioner is controlled to return to heating mode. If the air conditioner continues to be in heating mode and the running time still does not exceed the first preset time, the outdoor ambient temperature and outdoor coil temperature continue to be monitored in real time. Once icing of the outdoor heat exchanger is detected again, the air conditioner is controlled to re-enter defrost mode.

[0062] It should be noted that even after the air conditioner's operating time is greater than or equal to the first preset duration, the system will continue to monitor the outdoor heat exchanger for frost in real time. Once frost is detected on the surface of the outdoor heat exchanger, the defrosting mechanism will be triggered to ensure that heat exchange efficiency is not affected. During this process, the system can perform multiple defrosting operations based on the actual frost situation, thereby ensuring the stable performance and heating effect of the air conditioner during long-term operation.

[0063] Furthermore, step 800 may include the following: If the defrosting time exceeds the second preset time for a number of consecutive preset cycles, the temperature threshold corresponding to the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature is reduced.

[0064] In this embodiment, the number of consecutive preset times is 2, and the second preset duration is 8 minutes.

[0065] Understandably, if the defrosting time exceeds the second preset time for a series of preset times, the freezing or frost situation is considered to be relatively serious. In this case, the triggering conditions for subsequent defrosting or defrosting operations can be adjusted, specifically by lowering the second or fourth threshold temperature.

[0066] Optionally, step 700, obtaining the defrosting time, may include the following: The defrosting duration is obtained when the current outdoor coil temperature is greater than or equal to the fifth temperature threshold; where the fifth temperature is greater than the first temperature threshold.

[0067] Understandably, when an air conditioner enters defrost mode to heat the outdoor heat exchanger, defrosting ends when the current outdoor coil temperature rises to a level greater than or equal to the fifth temperature threshold. The duration of this defrost cycle is recorded and obtained as the defrost duration.

[0068] The fifth temperature threshold is set higher than the first temperature threshold to ensure that the defrosting time is only effectively recorded when the coil temperature rises to a certain level and the defrosting process is basically completed. In this embodiment, the fifth temperature threshold is 10℃, so Te ≥ 10℃, and defrosting ends.

[0069] In this embodiment, the air conditioner enters defrost mode when the four-way valve of the air conditioner switches to refrigeration cycle, the compressor runs, and the fans of the outdoor unit and indoor unit stop.

[0070] It's important to note that during the heating process of an air conditioner, the compressor is in operation. However, when the outdoor heat exchanger enters the defrosting stage, the system switches to cooling mode and heats the outdoor heat exchanger through reverse operation to achieve the defrosting effect. In this process, the defrosting time is essentially the compressor's operating time; that is, the defrosting process itself is part of the compressor's work. Therefore, the air conditioner's operating time refers to the cumulative operating time of the compressor, which includes the normal heating operating time and the compressor's operating time (defrosting time) during multiple defrosting processes.

[0071] In one specific embodiment of the present invention, such as Figure 6 As shown, the method includes the following steps: S10. When the air conditioner is turned on and in heating mode, obtain the compressor's running time, the current outdoor ambient temperature, and the current outdoor coil temperature.

[0072] S20. If the current outdoor ambient temperature is greater than zero, determine that the air conditioner does not need to enter defrost mode.

[0073] Understandably, when the current outdoor ambient temperature is detected to be higher than 0℃, it is determined that the ambient temperature is too high and the conditions for icing are not met, so there is no need to execute the icing judgment logic; in this case, the air conditioner will turn on directly and enter the heating mode.

[0074] S30. Determine if there is initial icing on the outdoor heat exchanger.

[0075] Specifically, if the running time is less than the first preset time and the current outdoor ambient temperature is less than zero, based on the current outdoor ambient temperature and the current outdoor coil temperature, the following three conditions are determined: Condition 1: Is the current outdoor ambient temperature Tao less than the first temperature threshold T1? Condition 2: Is the temperature difference ΔT between the current outdoor ambient temperature Tao and the current outdoor coil temperature Te greater than or equal to the second temperature threshold T2? Condition 3: Is the current outdoor coil temperature Te less than or equal to the third temperature threshold T3? When all three conditions are met, i.e. Tao < T1 and ΔT ≥ T2 and Te ≤ T3, it is determined that the outdoor heat exchanger has initial freezing, and step S40 is executed.

[0076] It should be noted that when the following conditions are not met: Tao < T1 and ΔT ≥ T2 and Te ≤ T3, it is determined that there is no initial icing phenomenon in the outdoor heat exchanger. In this case, the air conditioner does not need to enter the defrost mode, but continues to operate in the heating mode to maintain normal heating function.

[0077] S40. When the outdoor heat exchanger is frozen, control the air conditioner to enter defrost mode.

[0078] It is understandable that when the outdoor heat exchanger is initially frozen, the air conditioner will skip the normal heating mode and directly enter the defrost mode.

[0079] In step S40, the defrosting mode can be: controlling the air conditioner to enter the cooling mode, and stopping the fans of the outdoor unit and the indoor unit to heat the outdoor heat exchanger; when the outdoor coil temperature rises to greater than or equal to the fifth temperature threshold, it is determined that the defrosting is over, and the air conditioner is switched to the heating mode; the duration of this defrosting is recorded and obtained as the defrosting duration.

[0080] In this embodiment, the fifth temperature threshold is 10°C. The condition for determining the end of defrosting can be: the outdoor coil temperature is greater than or equal to 10°C and maintained for 30 seconds, and the frost layer is determined to have melted, so as to avoid interference from false signals.

[0081] S50. Repeatedly check whether there is ice buildup on the outdoor heat exchanger.

[0082] Specifically, if the runtime is less than the first preset duration, and the runtime is still less than the first preset duration, the process of steps S30 to S40 is repeated until the runtime is greater than or equal to the first preset duration, and then step S60 is executed.

[0083] It should be noted that if the defrosting time for a number of consecutive preset times exceeds the second preset time, the temperature difference value of the subsequent defrosting entry condition will be reduced; for example, if the defrosting time for two consecutive times is greater than 8 minutes, the second temperature threshold T2 will be reduced by 2℃.

[0084] S60. Determine if the outdoor heat exchanger is frosted.

[0085] Specifically, based on the current outdoor ambient temperature and the current outdoor coil temperature, the following two conditions are considered: The first condition is whether the temperature difference ΔT between the current outdoor ambient temperature Tao and the current outdoor coil temperature Te is greater than or equal to the fourth temperature threshold T4, and continues for the first duration. The second condition is whether the current outdoor coil temperature cooling rate dTe / dt is greater than the preset rate threshold α and continues for a second duration. When any of the above conditions are met, it is determined that the surface of the outdoor heat exchanger has been frosted, so that the air conditioner is controlled to enter the defrost mode.

[0086] It should be noted that if neither of these two conditions is met, it is determined that there is no frost on the outdoor heat exchanger; in this case, the air conditioner does not need to enter defrost mode, but continues to operate in heating mode to maintain normal heating function.

[0087] In step S60, the defrosting mode can be: controlling the air conditioner to enter the cooling mode, and stopping the fans of the outdoor unit and the indoor unit to heat the outdoor heat exchanger; when the outdoor coil temperature rises to greater than or equal to the fifth temperature threshold, it is determined that the defrosting is over, and the air conditioner is switched to the heating mode; the duration of this defrosting is recorded and obtained as the defrosting duration.

[0088] It should be noted that if the defrosting time for a number of consecutive preset times exceeds the second preset time, the temperature difference value for subsequent defrosting conditions will be reduced; for example, if the defrosting time for two consecutive times is greater than 8 minutes, the fourth temperature threshold T4 will be reduced by 2℃.

[0089] The control device for an air conditioner provided by the present invention is described below. The control device for an air conditioner described below can be referred to in correspondence with the control method for an air conditioner described above.

[0090] Embodiments of the present invention provide a control device for an air conditioner, such as... Figure 7 As shown, the control device includes an acquisition module 710, a first judgment module 720, and a first control module 730; wherein: The acquisition module 710 is used to acquire the compressor's running time, the current outdoor ambient temperature, and the current outdoor coil temperature when the air conditioner is turned on and in heating mode.

[0091] The first judgment module 720 is used to determine whether the outdoor heat exchanger is icing based on the current outdoor ambient temperature and the current outdoor coil temperature when the running time is less than the first preset time.

[0092] The first control module 730 is used to control the air conditioner to enter defrost mode when the outdoor heat exchanger is icy.

[0093] Optionally, the control device further includes: The second judgment module is used to determine whether the outdoor heat exchanger is frosted when the running time is greater than or equal to the first preset time, based on the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature and / or the cooling rate of the current outdoor coil temperature. The second control module is used to control the air conditioner to enter defrost mode when the outdoor heat exchanger is frosted.

[0094] Figure 8 An example is a schematic diagram of an air conditioning system, such as... Figure 8 As shown, the electronic device may include a processor 810, a communications interface 820, a memory 830, and a communication bus 840. The processor 810, communications interface 820, and memory 830 communicate with each other via the communication bus 840. The processor 810 can call logical instructions in the memory 830 to execute a control method for the air conditioner. This method includes: when the air conditioner is turned on and in heating mode, acquiring the compressor's running time, the current outdoor ambient temperature, and the current outdoor coil temperature; if the running time is less than a first preset time, determining whether the outdoor heat exchanger is icing based on the current outdoor ambient temperature and the current outdoor coil temperature; and if the outdoor heat exchanger is icing, controlling the air conditioner to enter defrost mode.

[0095] Furthermore, the logical instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0096] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the control method for the air conditioner provided by the above methods. The method includes: when the air conditioner is turned on and in heating mode, acquiring the compressor's running time, the current outdoor ambient temperature, and the current outdoor coil temperature; when the running time is less than a first preset time, determining whether the outdoor heat exchanger is icing based on the current outdoor ambient temperature and the current outdoor coil temperature; and when the outdoor heat exchanger is icing, controlling the air conditioner to enter defrost mode.

[0097] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When executed by a processor, the computer program implements the control method for an air conditioner provided by the above methods. The method includes: when the air conditioner is turned on and in heating mode, acquiring the compressor's running time, the current outdoor ambient temperature, and the current outdoor coil temperature; when the running time is less than a first preset time, determining whether the outdoor heat exchanger is icing based on the current outdoor ambient temperature and the current outdoor coil temperature; and when the outdoor heat exchanger is icing, controlling the air conditioner to enter defrost mode.

[0098] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0099] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of various embodiments or some parts of embodiments.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for an air conditioner, characterized in that, include: When the air conditioner is turned on and in heating mode, obtain the compressor's running time, the current outdoor ambient temperature, and the current outdoor coil temperature. If the running time is less than the first preset time, it is determined whether the outdoor heat exchanger is icing based on the current outdoor ambient temperature and the current outdoor coil temperature. When the outdoor heat exchanger is frozen, the air conditioner is controlled to enter defrost mode.

2. The control method for an air conditioner according to claim 1, characterized in that, The step of determining whether the outdoor heat exchanger is icing based on the current outdoor ambient temperature and the current outdoor coil temperature includes: Compare the current outdoor ambient temperature with the current outdoor coil temperature; If the current outdoor ambient temperature is less than a first temperature threshold, the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature is greater than or equal to a second temperature threshold, and the current outdoor coil temperature is less than or equal to a third temperature threshold, it is determined that the outdoor heat exchanger is icing; wherein the second temperature threshold is greater than the first temperature threshold, and the third temperature threshold is less than the first temperature threshold.

3. The control method for an air conditioner according to claim 2, characterized in that, The method further includes: If the running time is greater than or equal to the first preset time, it is determined whether the outdoor heat exchanger is frosted based on the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature and / or the cooling rate of the current outdoor coil temperature. When the outdoor heat exchanger is frosted, the air conditioner is controlled to enter defrost mode.

4. The control method for an air conditioner according to claim 3, characterized in that, Based on the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature, determine whether the outdoor heat exchanger is frosted, including: Compare the current outdoor ambient temperature with the current outdoor coil temperature; If the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature is greater than or equal to a fourth temperature threshold, it is determined that the outdoor heat exchanger is frosted; wherein the fourth temperature threshold is less than the second temperature threshold.

5. The control method for an air conditioner according to claim 3, characterized in that, Based on the cooling rate of the current outdoor coil temperature, determine whether the outdoor heat exchanger is frosted, including: Determine the cooling rate of the current outdoor coil temperature; If the cooling rate is greater than a preset rate threshold, it is determined that the outdoor heat exchanger is frosted.

6. The control method for an air conditioner according to any one of claims 1 to 5, characterized in that, Before determining whether the outdoor heat exchanger is icing based on the current outdoor ambient temperature and the current outdoor coil temperature, the method further includes: If the current outdoor ambient temperature is greater than zero, it is determined that the air conditioner does not need to enter defrost mode.

7. The control method for an air conditioner according to any one of claims 2 to 5, characterized in that, After controlling the air conditioner to enter defrost mode, the method further includes: Get defrost duration; If the defrosting time exceeds the second preset time, the temperature threshold corresponding to the temperature difference between the current outdoor ambient temperature and the current outdoor coil temperature is reduced.

8. The control method for an air conditioner according to claim 7, characterized in that, The process of obtaining the defrosting time includes: If the current outdoor coil temperature is greater than or equal to a fifth temperature threshold, the defrosting duration is obtained; wherein the fifth temperature is greater than the first temperature threshold.

9. A control device for an air conditioner, characterized in that, include: The acquisition module is used to acquire the compressor's running time, the current outdoor ambient temperature, and the current outdoor coil temperature when the air conditioner is turned on and in heating mode. The first judgment module is used to determine whether the outdoor heat exchanger is icing up, based on the current outdoor ambient temperature and the current outdoor coil temperature, when the running time is less than the first preset time. The first control module is used to control the air conditioner to enter defrost mode when the outdoor heat exchanger is frozen.

10. An air conditioning system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the control method for the air conditioner as described in any one of claims 1 to 8.

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