Defrosting control method and system based on COP attenuation rate, air conditioner and medium

Abstract

The invention discloses a defrosting control method and system based on the COP attenuation rate, an air conditioner and a medium. The method comprises the steps that the rotating speed of an indoor fan, the temperature of an indoor coil pipe and consumption power are collected; according to the rotating speed of the indoor draught fan, the temperature of the indoor coil pipe and the consumption power, a COP mean value and a COP maximum value are obtained through calculation; according to the COP mean value and the COP maximum value, calculating to obtain a COP attenuation rate; and according to the COP attenuation rate, the air conditioner is controlled to enter a first-stage frost restraining mode, a second-stage frost restraining mode or a reversing defrosting mode. The defrosting opportunity can be accurately determined, the problem that hysteresis exists in defrosting and the comfort degree of a user is affected is solved, and the method can be widely applied to the technical field of air conditioners.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and in particular to a defrosting control method, system, air conditioner and medium based on COP decay rate. Background Technology

[0002] During winter heating operation, the surface of the heat exchanger in the outdoor unit of an air conditioner may frost up due to the low temperature and high humidity environment. This frost layer severely hinders heat exchange, leading to a decrease in system heating capacity, increased energy consumption, and even damage to the compressor. Traditional defrosting control methods, such as timed defrosting, temperature-time combined control, and differential pressure or airflow detection, do not directly reflect the degree of system performance deterioration based on frost indicators (such as time and temperature). This results in inaccurate defrosting timing, lag, and negatively impacts user comfort and energy waste. Summary of the Invention

[0003] The main objective of this application is to propose a defrosting control method, system, air conditioner, and medium based on COP decay rate, which can quantify the degree of system performance loss in real time and accurately determine the defrosting timing.

[0004] To achieve the above objectives, one aspect of this application proposes a defrosting control method based on COP decay rate, comprising the following steps: Collect indoor fan speed, indoor coil temperature, and power consumption; The average COP and the maximum COP are calculated based on the indoor fan speed, the indoor coil temperature, and the power consumption. The COP decay rate is calculated based on the mean COP and the maximum COP. Based on the COP decay rate, the air conditioner is controlled to enter the first-level defrost mode, the second-level defrost mode, or the reversing defrost mode.

[0005] In some embodiments, calculating the average COP and the maximum COP based on the indoor fan speed, the indoor coil temperature, and the power consumption specifically includes: Construct a linear model of speed-air volume, input the indoor fan speed into the linear model of speed-air volume, and obtain the air volume value; The virtual capacity value is calculated based on the air volume value and the indoor coil temperature. Calculate the COP value for each detection cycle based on the virtual capability value and the power consumption; The average COP value is obtained by calculating the average COP value over the detection period; Based on the COP value, the maximum COP value is obtained from the time the air conditioner is turned on until COP decay occurs.

[0006] In some embodiments, calculating the COP decay rate based on the mean COP and the maximum COP specifically includes: The difference between the mean COP and the maximum COP is calculated, and then the difference is divided by the maximum COP to obtain the COP decay rate. The formula for calculating the COP attenuation rate is as follows: ; in, The COP decay rate, The mean COP is... This is the maximum value of COP.

[0007] In some embodiments, controlling the air conditioner to enter a primary defrost mode, a secondary defrost mode, or a reversing defrost mode based on the COP decay rate specifically includes: Collect outdoor coil temperature and outdoor ambient temperature; When the COP decay rate is greater than the first grade threshold and the COP decay rate is less than or equal to the second grade threshold in multiple consecutive detection cycles, the air conditioner is controlled to enter the first-level defrost mode. When the COP decay rate is greater than the second grade threshold and the COP decay rate is less than or equal to the third grade threshold in multiple consecutive detection cycles, the air conditioner is controlled to enter the second-level defrost mode. When the COP decay rate is greater than the third grade threshold in multiple consecutive detection cycles, and / or the outdoor coil temperature is less than the difference between the outdoor ambient temperature and the frosting temperature threshold, the air conditioner is controlled to enter the reversing defrosting mode. Wherein, the first grading threshold is less than the second grading threshold, and the second grading threshold is less than the third grading threshold.

[0008] In some embodiments, controlling the air conditioner to enter the first-level defrost mode specifically includes: Obtain the current expansion valve opening of the air conditioner; Based on the current expansion valve opening, the COP decay rate, and the first grading threshold, the first target expansion valve opening is calculated, and then the current expansion valve opening is adjusted to increase to the first target expansion valve opening. The target fan speed is calculated based on the indoor fan speed, the COP attenuation rate, and the first grading threshold, and then the indoor fan speed is adjusted to be reduced to the target fan speed.

[0009] In some embodiments, controlling the air conditioner to enter the secondary defrost mode specifically includes: Obtain the initial compressor operating frequency and current expansion valve opening of the air conditioner; The target operating frequency is calculated based on the initial press operating frequency, the COP attenuation rate, and the second grading threshold, and then the initial press operating frequency is adjusted to be reduced to the target operating frequency. Based on the current expansion valve opening, the COP decay rate, and the second grading threshold, the second target expansion valve opening is calculated, and then the current expansion valve opening is adjusted to increase to the second target expansion valve opening.

[0010] In some embodiments, controlling the air conditioner to enter the reversing defrosting mode specifically includes: Adjust the compressor operating frequency of the air conditioner to reduce it to the first operating frequency; Control the four-way valve to switch directions, thereby shutting down the indoor and outdoor fans; The compressor operating frequency of the air conditioner is controlled to operate at a second operating frequency; If the outdoor coil temperature at the current moment is greater than the steady-state temperature threshold and remains so for a first duration, control the compressor operating frequency of the air conditioner to operate at the first operating frequency; If the current outdoor coil temperature is greater than the sum of the outdoor ambient temperature and the defrosting temperature threshold, and this remains for a second duration, control the four-way valve to switch directions. The first operating frequency is less than the second operating frequency.

[0011] To achieve the above objectives, another aspect of this application provides a control system, comprising: At least one processor; At least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor performs the method described above.

[0012] To achieve the above objectives, another aspect of the embodiments of this application proposes an air conditioner, including the control system as described above.

[0013] To achieve the above objectives, another aspect of the embodiments of this application proposes a computer-readable storage medium storing computer-executable instructions for performing the methods described above.

[0014] The embodiments of this application include at least the following beneficial effects: This application provides a defrosting control method, system, air conditioner, and medium based on COP decay rate. First, it collects indoor fan speed, indoor coil temperature, and power consumption. Then, based on the indoor fan speed, indoor coil temperature, and power consumption, it calculates the average and maximum COP values. Next, it calculates the COP decay rate based on the average and maximum COP values. Finally, based on the COP decay rate, it controls the air conditioner to enter a first-level defrosting mode, a second-level defrosting mode, or a reversing defrosting mode. This application calculates the COP decay rate based on the indoor fan speed, indoor coil temperature, and the air conditioner's power consumption, and then quantifies the performance loss caused by frost in real time using the COP decay rate. Based on this quantification, it performs graded defrosting or reversing defrosting, which can accurately determine the defrosting timing and solve the problems of defrosting lag and its impact on user comfort. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments of this application are described below. It should be understood that the drawings described below are only for the purpose of clearly illustrating some embodiments of the technical solutions in this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 A flowchart illustrating the steps of a defrosting control method based on COP decay rate provided in one embodiment of this application; Figure 2 This is a schematic flowchart of a defrosting control method based on COP decay rate provided in one embodiment of this application; Figure 3 This is a schematic diagram of the structure of a control system provided in one embodiment of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.

[0018] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various concepts, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words “if,” “when,” or “in response to a determination” as used herein may be interpreted as “when…” or “when…” or “in response to a determination.”

[0019] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.

[0020] During winter heating operation, the surface of the heat exchanger in the outdoor unit of an air conditioner may frost up due to the low temperature and high humidity environment. This frost layer severely hinders heat exchange, leading to a decrease in system heating capacity, increased energy consumption, and even damage to the compressor. Traditional defrosting methods have the following drawbacks: (1) Timed defrosting method: It is simple but not precise enough, and it is easy to cause problems such as "defrosting when there is no frost" or "not defrosting when there is frost".

[0021] (2) Temperature-time combined control method: By monitoring the outdoor ambient temperature and heat exchanger tube temperature, the defrosting time is determined in combination with the running time. This method is an improvement over the timed method, but it is not very adaptable to complex working conditions and has obvious lag.

[0022] (3) Pressure difference or airflow detection method: Frost formation is determined by detecting the air pressure difference or wind speed change on both sides of the heat exchanger, but the sensor cost is high and it is easily interfered with.

[0023] In summary, the shortcomings of traditional defrosting methods are that the indicators for judging frost formation (such as time and temperature) do not directly reflect the degree of deterioration in system performance, resulting in inaccurate defrosting timing, lag, impact on user comfort, and energy waste.

[0024] In view of this, this application proposes a defrosting control method based on COP decay rate. First, the indoor fan speed, indoor coil temperature, and power consumption are collected. Then, the average and maximum COP values ​​are calculated based on these parameters. Next, the COP decay rate is calculated based on the average and maximum COP values. Finally, based on the COP decay rate, the air conditioner is controlled to enter a first-level defrosting mode, a second-level defrosting mode, or a reversing defrosting mode. This application calculates the COP decay rate based on the indoor fan speed, indoor coil temperature, and the air conditioner's power consumption, and then quantifies the performance loss caused by frost in real time using the COP decay rate. Based on this quantification, graded defrosting or reversing defrosting is performed, which can accurately determine the defrosting timing and solve the problems of defrosting lag and its impact on user comfort.

[0025] The embodiments of this application will be further described below with reference to the accompanying drawings.

[0026] Reference Figure 1 , Figure 1 This is a flowchart of the defrosting control method based on COP decay rate provided in one embodiment of this application. The embodiment of this application proposes a defrosting control method based on COP decay rate, which may include, but is not limited to, the following steps S100 to S400.

[0027] Step S100: Collect indoor fan speed, indoor coil temperature, and power consumption; Specifically, during the heating operation phase of the air conditioner, the indoor fan speed Fan and indoor coil temperature T are collected in real time based on the detection cycle t. 内管 And the power consumption P of the air conditioner. Among them, the indoor fan speed Fan is used to characterize the operating speed of the indoor fan, and the indoor coil temperature T... 内管 Used to characterize the tube temperature of indoor heat exchangers.

[0028] It is understood that the detection period t in the embodiments of this application can be set according to actual application requirements. For example, the detection period t is set to 40s or 60s.

[0029] Step S200: Calculate the average COP and the maximum COP based on the indoor fan speed, indoor coil temperature, and power consumption. Specifically, based on the indoor fan speed Fan and the indoor coil temperature T 内管 In addition to the power consumption P, calculate the average COP within the detection period t, and the maximum COP during the period from when the air conditioner starts running until the COP value begins to decay.

[0030] As an optional implementation, step S200 can be further divided into the following steps S201 to S205: Step S201: Construct a linear model of speed-air volume. Input the indoor fan speed into the linear model of speed-air volume to obtain the air volume value. Specifically, based on the indoor fan speed setting, the corresponding relationship between speed and air volume can be obtained from the experimentally tested air volume, resulting in the setting-air volume relationship table shown in Table 1 below.

[0031] Table 1

[0032] By approximating a linear relationship between airflow and indoor fan speed, the following linear model of speed-airflow is obtained, which is then used to calculate the currently collected indoor fan speed. Substituting into the linear model of rotational speed and air volume, the corresponding air volume value is obtained. : ; in, This is a constant coefficient, the value of which can be obtained through experimental calibration based on the actual air conditioner model.

[0033] Step S202: Calculate the virtual capacity value based on the air volume value and the indoor coil temperature; Specifically, the virtual capacity value is calculated based on the air volume and indoor coil temperature using the following formula. : ; in, This is a correction factor for the virtual capability value. Its value can be obtained through experimental calibration based on the actual air conditioner model, so that the virtual capability value is close to the actual test value.

[0034] Step S203: Calculate the COP value based on the virtual capability value and power consumption; Specifically, COP value = heating capacity / power. When the outside is severely frosted, the heating capacity gradually decreases while the power does not change much, and the COP value will gradually decrease. Therefore, this embodiment uses the COP value to reflect the defrosting status of the air conditioner, and its value is calculated by the following formula: .

[0035] Step S204: Calculate the average COP value over the detection period to obtain the average COP value; Step S205: Based on the COP value, obtain the maximum COP value from the time the air conditioner is turned on until COP decay occurs.

[0036] Specifically, based on the COP values ​​obtained above, the average COP value within each detection period t can be determined, as well as the maximum COP value during the period from when the air conditioner is turned on until the COP value begins to decay.

[0037] It is understandable that the above linear model of speed-air volume and the formula for calculating virtual capacity are only examples. In actual applications, more complex functions or fuzzy control logic can be used according to actual parameters to achieve a smoother transition.

[0038] Step S300: Calculate the COP decay rate based on the mean COP and the maximum COP. As an optional implementation, step S300 can be further divided into the following steps S301 to S302: Step S301: Calculate the difference between the mean COP and the maximum COP. Step S302: Divide the difference obtained from the difference calculation with the maximum value of COP to obtain the COP attenuation rate; The formula for calculating the COP decay rate is: ; in, COP decay rate, The mean COP This represents the maximum value of COP.

[0039] It should be noted that under normal operating conditions (assuming startup at 4°C), the outdoor ambient temperature changes slowly. As the temperature decreases, the outer heat exchanger gradually frosts up, and the COP change rate gradually increases until defrosting begins. There is an extreme critical point where a brief change in operating parameters causes a sudden drop in COP. In this case, defrosting is not initiated. The COP decay rate is recorded only after the air conditioner's operating parameters stabilize (e.g., steady-state duration t1) to improve the accuracy of COP decay rate calculation. The steady-state duration t1 can be set according to the actual air conditioner model and performance; for example, t1 is set to 40 seconds.

[0040] Specifically, the COP value is continuously monitored and recorded within each detection period t, and the COP decay rate within that detection period t is calculated. ,Right now: .

[0041] Step S400: Based on the COP attenuation rate, control the air conditioner to enter the first-level defrost mode, the second-level defrost mode, or the reversing defrost mode.

[0042] It should be noted that the COP decay rate directly reflects the decline in the heating capacity of the air conditioner, and thus reflects the degree of frost formation on the outdoor heat exchanger. Therefore, this application embodiment quantifies the performance loss caused by frost formation in real time through the COP decay rate: when the COP decay rate... A lower value indicates that the air conditioner has not frosted; when the COP decay rate... Moderate indicates slight frost buildup on the air conditioner; when the COP decay rate... A higher COP indicates moderate frost buildup in the air conditioner; when the COP decay rate... A high value indicates that the air conditioner is heavily frosted and needs to be defrosted; based on this quantitative level, graded and gradual defrosting or defrosting control will be implemented.

[0043] As an optional implementation, step S400 can be further divided into steps S401 to S404: Step S401: Collect the outdoor coil temperature and the outdoor ambient temperature; Step S402: When the COP decay rate is greater than the first grade threshold and the COP decay rate is less than or equal to the second grade threshold in multiple consecutive detection cycles, control the air conditioner to enter the first grade defrost mode. Step S403: When the COP decay rate is greater than the second grade threshold and the COP decay rate is less than or equal to the third grade threshold in multiple consecutive detection cycles, control the air conditioner to enter the second grade defrost mode. Step S404: When the COP decay rate is greater than the third grade threshold in multiple consecutive detection cycles, and / or the outdoor coil temperature is less than the difference between the outdoor ambient temperature and the frosting temperature threshold, control the air conditioner to enter the reversing defrosting mode. Among them, the first level threshold is less than the second level threshold, and the second level threshold is less than the third level threshold.

[0044] It should be noted that in the defrosting detection of this application embodiment, different attenuation rate intervals are divided, and the parameter change feedback obtained in each interval is different; by adjusting different operating parameters through different attenuation rate intervals, the unit's operating status is coordinated more reasonably and intelligently, reducing unnecessary defrosting times and improving the air conditioner's efficiency and user comfort.

[0045] In some optional embodiments, after the air conditioner's operating parameters stabilize, the COP decay rate is continuously detected for more than a few detection cycles t (e.g., 3 cycles) before defrosting is determined, in order to avoid false detections.

[0046] When the COP decay rate over multiple consecutive detection cycles Less than or equal to the first grade threshold ,Right now This indicates that the air conditioner is not frosted and its heating performance has not decreased, so it is operating normally without any parameter adjustments.

[0047] When the COP decay rate over multiple consecutive detection cycles Greater than the first grade threshold And COP decay rate Less than or equal to the second grade threshold ,Right now This indicates that the air conditioner is experiencing slight frost buildup and a decrease in heating performance. The first-level optimization adjustment is activated, controlling the air conditioner to enter the first-level defrost mode. In this mode, the opening of the system's electronic expansion valve is increased to suppress the rate of frost buildup on the air conditioner.

[0048] When the COP decay rate over multiple consecutive detection cycles Greater than the second grade threshold And COP decay rate Less than or equal to the third-level threshold ,Right now This indicates that the air conditioner is experiencing moderate frost buildup, which accelerates the decline in heating performance. The secondary optimization adjustment is then activated, controlling the air conditioner to enter the secondary defrost mode. In this mode, the opening of the system's electronic expansion valve is further increased to suppress the rate of frost buildup in the air conditioner.

[0049] When the COP decay rate over multiple consecutive detection cycles Greater than the third grade threshold ,Right now and / or outdoor coil temperature Lower than the outdoor ambient temperature With frosting temperature threshold The difference, i.e. This indicates that the air conditioner is experiencing moderate frost buildup, resulting in a significant decrease in heating performance, and prompts the air conditioner to enter reversing defrosting mode.

[0050] Understandably, the frosting temperature threshold This value is used to characterize whether the outdoor ambient temperature meets the conditions for frosting. It can be set according to the actual outdoor ambient temperature and the air conditioner model and performance. First-level threshold. Second-level threshold and the third-level threshold All of these can be calibrated experimentally (under different temperature and humidity conditions) based on the air conditioner's capacity and heat exchanger design, and can be fine-tuned according to real-time outdoor ambient temperature or humidity. For example, a third-level threshold can be set. It decreases as the outdoor ambient temperature decreases. Among them, , .

[0051] As an optional implementation, the step of controlling the air conditioner to enter the first-level defrost mode can be further divided into the following steps S4021 to S4023: Step S4021: Obtain the current opening degree of the air conditioner's expansion valve; Step S4022: Calculate the first target expansion valve opening based on the current expansion valve opening, COP decay rate and the first grade threshold, and then adjust the current expansion valve opening to increase to the first target expansion valve opening. Step S4023: Calculate the target fan speed based on the indoor fan speed, COP attenuation rate and the first grade threshold, and then adjust the indoor fan speed to reduce it to the target fan speed.

[0052] In some optional embodiments, in the first-level defrosting mode, the electronic expansion valve opening and the internal fan speed are adjusted; the expansion valve opening is adjusted first, followed by the internal fan speed. First, based on the current expansion valve opening... COP decay rate and the first grade threshold The first target expansion valve opening is calculated using the following formula. This further increases the opening of the electronic expansion valve to the first target expansion valve opening. : ; Among them, the increase in aperture and the COP decay rate Exceeding the first grade threshold The part is directly proportional. The duration of the detection period t, It is a proportionality coefficient (positive number), the value of which can be obtained through experimental calibration based on the actual air conditioner model.

[0053] Secondly, appropriately reduce the internal fan speed and recalculate the COP decay rate at intervals of detection period t. According to the indoor fan speed COP decay rate and the first grade threshold The target fan speed is calculated using the following formula. This reduces the indoor fan speed to the target fan speed. : ; Among them, the speed decay and the COP decay rate Exceeding the first grade threshold The part is directly proportional. This is a proportionality coefficient, the value of which can be obtained through experimental calibration based on the actual air conditioner model.

[0054] As an optional implementation, the step of controlling the air conditioner to enter the secondary defrost mode can be further divided into the following steps S4031 to S4033: Step S4031: Obtain the initial compressor operating frequency and current expansion valve opening of the air conditioner; Step S4032: Calculate the target operating frequency based on the initial press operating frequency, COP attenuation rate and the second grade threshold, and then adjust the initial press operating frequency to reduce it to the target operating frequency; Step S4033: Calculate the second target expansion valve opening based on the current expansion valve opening, COP decay rate, and second grade threshold, and then adjust the current expansion valve opening to increase it to the second target expansion valve opening.

[0055] In some optional embodiments, in the two-stage defrost mode, the compressor operating frequency is corrected and the electronic expansion valve opening is adjusted. First, based on the initial compressor operating frequency... COP decay rate and the second grade threshold The target operating frequency of the compressor is calculated using the following formula. This reduces the compressor's operating frequency to the target operating frequency. : ; in, This is a proportionality coefficient, the value of which can be obtained through experimental calibration based on the actual air conditioner model.

[0056] During the adjustment of the press operating frequency, continue to increase the opening of the electronic expansion valve, adjusting it according to the following formula: .

[0057] It should be noted that, in the early stage of heating performance loss, the parameter self-adjustment of the first or second level defrost mode is activated to actively defrost and maintain performance, which can significantly extend the continuous heating time of the air conditioner and improve user comfort and energy efficiency.

[0058] As an optional implementation, the step of controlling the air conditioner to enter the reversing defrosting mode can be further divided into the following steps S4041 to S4045: Step S4041: Adjust the compressor operating frequency of the air conditioner to reduce it to the first operating frequency; Step S4042: Control the four-way valve to switch directions, thereby shutting down the indoor fan and the outdoor fan; Step S4043: Control the compressor operating frequency of the air conditioner to operate at the second operating frequency; Step S4044: If the outdoor coil temperature at the current moment is greater than the steady-state temperature threshold and is maintained for a first duration, control the compressor operating frequency of the air conditioner to operate at the first operating frequency. Step S4045: If the outdoor coil temperature at the current moment is greater than the sum of the outdoor ambient temperature and the defrosting temperature threshold, and this is maintained for the second duration, control the four-way valve to switch directions. The first operating frequency is less than the second operating frequency.

[0059] In some optional embodiments, in the reversing defrosting mode, the compressor operating frequency is first slowly reduced to a first operating frequency F_1, the four-way valve is controlled to reverse, switching to the refrigeration cycle, and then the indoor and outdoor fans are turned off; next, the compressor operating frequency is controlled to operate at a second operating frequency F_2, delivering high-temperature refrigerant to the outdoor heat exchanger for rapid defrosting; then the coil temperature of the outdoor heat exchanger (i.e., the outdoor coil temperature T) is monitored. 外管 When the outdoor coil temperature T 外管 After reaching the steady-state temperature threshold T_1 and stabilizing for a first duration (e.g., 30 seconds), the compressor operating frequency is switched to the first operating frequency F_1 to thoroughly defrost and evaporate residual moisture; when the outdoor coil temperature T 外管 >Outdoor ambient temperature T 外环 + defrost temperature threshold T_t, and continue for a second duration (e.g., 30s) to determine the outdoor coil temperature T. 外管 Once the preset defrosting completion temperature is reached, defrosting is complete. At this point, the four-way valve is switched back to normal, the heating mode is restored, and the frosting level judgment is reset.

[0060] It is understandable that the first operating frequency F_1 and the second operating frequency F_2 can be set according to actual application requirements, and the first operating frequency F_1 is less than the second operating frequency F_2; the steady-state temperature threshold T_1 is used to characterize the stable defrosting temperature of the outdoor heat exchanger coil, and its value can be set according to the actual outdoor ambient temperature; the defrosting temperature threshold T_t is used to characterize the defrosting temperature of the coil, and its value can be set according to the actual outdoor ambient temperature.

[0061] Furthermore, if the COP value does not decrease within the testing period, the air conditioner will operate according to its original operating parameters.

[0062] It should be noted that in the initial first-level defrost mode, the system self-optimizes to delay performance degradation, implements defensive protection in the intermediate second-level defrost mode, and performs efficient defrosting only in the final reversing defrost mode, thereby achieving imperceptible, continuous, and highly efficient heating operation.

[0063] The control flow of the defrosting control method based on COP decay rate in this application embodiment has been described above. The specific process of this application embodiment will be further described below with reference to examples.

[0064] Scenario setting: The air conditioner is a 1.5 HP DC inverter wall-mounted heat pump air conditioner; the external environment is a winter evening, with an outdoor temperature of T. 外环=2℃, relative humidity is 85% (typical frosting condition); the user sets the air conditioner to heating mode, the air conditioner set temperature is 22℃, and the fan is set to automatic airflow (initial corresponding speed Fan=800rpm).

[0065] System initial state and parameter calibration: constant coefficients =0.05, correction coefficient for virtual ability values =0.85; First tier threshold =3%, second-level threshold =8%, third-level threshold =15% (at T) 外环 (at 2℃) proportionality coefficient =8. Proportionality coefficient =0.02, proportionality coefficient =0.01; Frosting temperature threshold T_h=5℃, defrosting temperature threshold T_t=12℃; Initial compressor operating frequency =90Hz; initial opening of the electronic expansion valve B0=300 steps.

[0066] Phase 1: The air conditioner operates at a stable heating speed; performance monitoring is conducted. After system startup, it quickly enters a stable heating state; the controller continuously calculates the virtual COP value. Assuming that after stabilization, the COP value fluctuates slightly around 4.2 (e.g., between 4.15 and 4.25), the COP decay rate is then calculated. (Use a 5-minute moving average) It fluctuates within ±2%, consistently remaining below the first-level threshold. (3%). The system determines that the air conditioner is not frosted and does not make any frosting-related adjustments. It only makes regular temperature control PID adjustments based on the room temperature, and the user feels warm and comfortable.

[0067] Phase Two: Air conditioner experiences slight frost buildup; Level One optimization adjustment is performed. Due to continuous low temperature and high humidity operation, the outdoor unit fins began to show slight frost formation, and the heat exchange efficiency slowly decreased. The COP value slowly decreased from 4.20 to 3.95 (a decrease of approximately 6%). The calculated 5-minute average COP decay rate... =5.5%. At this time... (3%) (5.5%)≤ (8%), the system determines that the air conditioner has slight frost and enters the first-level anti-frost mode.

[0068] In Level 1 defrosting mode, first adjust the electronic expansion valve, with an opening increment ΔB = *( - The number of steps is 8*(5.5-3)=20, so the opening degree of the first target expansion valve is... =300 + 20 = 320 steps. Open the valve wider to increase the system's evaporation pressure and alleviate frost formation.

[0069] If monitoring detects If the condition does not improve and rises to 6.0% (with the COP value continuing to decrease to 3.90), then the internal fan speed adjustment will be triggered, with the target fan speed set at... =800*[1-0.02*(6.0-3)]=800*0.94=752rpm.

[0070] Phase 3: Moderate frost buildup on the air conditioner; implement Level 2 protection adjustments. Without environmental improvement, the frost layer thickens, accelerating performance degradation. At this point, the COP value drops rapidly to 3.60. Calculate the COP degradation rate. =12%. At this time... (8%) (12%)≤ (15%), the system determines that the air conditioner has moderate frost and enters the second-level defrost mode.

[0071] In the two-stage defrosting mode, the compressor operating frequency is reduced, and the calculated target operating frequency is... =90*[1-0.01*(12-8)]=50*0.96=86Hz, to actively reduce the system load and prevent compressor low-pressure, overload, and other faults caused by severe evaporator blockage, thus protecting core components. A more aggressive adjustment is used to further increase the opening of the electronic expansion valve, with a second target expansion valve opening. =Current expansion valve opening + 8*(12-8) = Current expansion valve opening + 32 steps. The indoor fan is maintained at a low to medium speed.

[0072] Phase 4: The air conditioner is heavily frosted, and the frost layer has severely affected heat exchange. Reversing defrosting adjustment is required. The COP value drops sharply to 3.40. Calculate the COP decay rate. =18%. Meanwhile, the outdoor heat exchanger pipe temperature sensor reading T... 外管 =-4℃. Outdoor ambient temperature T 外环 It is still 2℃. (18%)> (15%), T 外管 (-4℃)<(T 外环 -T_h)=(2-5)=-3℃. When both frosting conditions are met simultaneously, the system confirms that the air conditioner is in "heavy frosting" mode and enters the reversing defrosting mode.

[0073] In reversing defrosting mode, defrosting is initiated first: the four-way valve is reversed, the indoor fan is shut off, the system switches to refrigeration cycle, and the compressor operates at its second operating frequency F_2 (96Hz) at full power, with high-temperature refrigerant flowing to the outdoor unit. Entering the defrosting process (high-frequency to medium-frequency): T is detected... 外管 It rose rapidly, and after about 2 minutes, T 外管 After the steady-state temperature threshold T_1 (3℃) is reached and stabilized for 30 seconds, the compressor operating frequency switches to the first operating frequency F_1 (50Hz) to continue melting residual frost and evaporating moisture. Defrosting ends approximately 3 minutes later. 外管 It rose to 18°C. Due to T 外环 =2℃, at this time T 外管 >(T 外环 + Defrost temperature threshold T_t = 2 + 12 = 14℃), and continue for 30 seconds. Resume heating: Control the four-way valve to switch back, the compressor restarts at a gentle frequency, the indoor fan blows out warm air with a delay, and the system re-enters stage one (no frost) and begins monitoring.

[0074] In summary, the processing flow of the defrosting control method based on COP decay rate in this application embodiment is as follows: Figure 2 As shown: The first step is to collect data on the indoor fan speed (Fan) and indoor coil temperature (T) during the air conditioner's heating operation. 内管 Power consumption P of the air conditioner, outdoor coil temperature T 外管 Outdoor ambient temperature T 外环 ; The second step is to calculate the COP value, and then calculate the COP decay rate. ; The third step is to determine the COP decay rate. The interval in which it is located; Fourth step, when The air conditioner is not frosted, its heating performance has not decreased, and it is operating at its current parameters. Fifth step, when If the air conditioner develops slight frost and its heating performance decreases, control the air conditioner to enter the first-level defrost mode: first increase the opening of the electronic expansion valve, then reduce the speed of the indoor fan. Step 6, when When the air conditioner experiences moderate frost buildup and its heating performance deteriorates rapidly, the system will switch to a secondary defrost mode: reducing the compressor's operating frequency and further increasing the opening of the electronic expansion valve. Step 7, when , and / or The air conditioner is experiencing moderate frost buildup, resulting in a significant decrease in heating performance. The air conditioner is then switched to reversing defrosting mode.

[0075] The control flow of the defrosting control method based on COP decay rate in the embodiments of this application has been described above. It can be recognized that, compared with traditional defrosting methods, this application has the following advantages: 1. By quantifying the performance loss caused by frosting in real time through the COP decay rate, and performing graded and gradual defrosting control based on this quantification, the problem of lag and misjudgment of traditional indirect criteria can be fundamentally solved. Second, during defrosting detection, different attenuation rate intervals are divided, and the parameter changes obtained in each interval are different. By adjusting different operating parameters through different attenuation rate intervals, the unit's operating status can be coordinated more reasonably and intelligently, reducing unnecessary defrosting times and improving the efficiency of air conditioner use and user comfort. Third, in the early stage of heating performance loss, the parameter self-adjustment of the first or second level defrost mode is activated, changing passive defrosting to active performance maintenance, which can significantly extend the continuous heating time of the air conditioner and improve user comfort and energy efficiency. Fourth, in the initial first-level defrosting mode, the system self-optimizes to delay performance degradation, implements defensive protection in the mid-term second-level defrosting mode, and performs efficient defrosting only in the final reversing defrosting mode, thereby achieving imperceptible, continuous, and highly efficient heating operation.

[0076] Based on the above-described defrosting control method based on COP decay rate, various embodiments of the control system, air conditioner, and computer-readable storage medium of this application are presented below.

[0077] Reference Figure 3 One embodiment of this application provides a control system, including: At least one processor 710; At least one memory 720 is used to store at least one program; When at least one program is executed by at least one processor 710, the at least one processor 710 implements the aforementioned defrosting control method based on COP decay rate.

[0078] It is evident that the content of the above method embodiments is applicable to this control system embodiment. The specific functions implemented by this control system embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0079] This application also provides an air conditioner, including the aforementioned control system.

[0080] Similarly, the content of the above method embodiments is applicable to this air conditioner embodiment. The specific functions implemented by this air conditioner embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0081] This application embodiment also provides a computer-readable storage medium storing a program executable by a processor 710, which, when executed by the processor 710, is used to perform the above-described defrosting control method based on COP decay rate.

[0082] Similarly, the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0083] Those skilled in the art will understand that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer-readable storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer-readable storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer-readable storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0084] In the foregoing description of this specification, the references to terms such as "one embodiment," "another embodiment," or "some embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0085] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

[0086] The above is a detailed description of the preferred embodiments of this application, but this application is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A defrosting control method based on COP decay rate, characterized in that, Includes the following steps: Collect indoor fan speed, indoor coil temperature, and power consumption; The average COP and the maximum COP are calculated based on the indoor fan speed, the indoor coil temperature, and the power consumption. The COP decay rate is calculated based on the mean COP and the maximum COP. Based on the COP decay rate, the air conditioner is controlled to enter the first-level defrost mode, the second-level defrost mode, or the reversing defrost mode.

2. The method according to claim 1, characterized in that, The calculation of the average and maximum COP based on the indoor fan speed, the indoor coil temperature, and the power consumption specifically includes: Construct a linear model of speed-air volume, input the indoor fan speed into the linear model of speed-air volume, and obtain the air volume value; The virtual capacity value is calculated based on the air volume value and the indoor coil temperature. The COP value is calculated based on the virtual capability value and the power consumption. The average COP value is obtained by calculating the average COP value over the detection period; Based on the COP value, the maximum COP value is obtained from the time the air conditioner is turned on until COP decay occurs.

3. The method according to claim 1, characterized in that, The calculation of the COP decay rate based on the mean COP and the maximum COP specifically includes: The difference between the mean COP and the maximum COP is calculated. The difference obtained from the difference calculation is divided by the maximum value of COP to obtain the COP attenuation rate; The formula for calculating the COP attenuation rate is as follows: ； in, The COP decay rate, The mean COP is... This is the maximum value of COP.

4. The method according to claim 1, characterized in that, The step of controlling the air conditioner to enter a first-level defrost mode, a second-level defrost mode, or a reversing defrost mode based on the COP decay rate specifically includes: Collect outdoor coil temperature and outdoor ambient temperature; When the COP decay rate is greater than the first grade threshold and the COP decay rate is less than or equal to the second grade threshold in multiple consecutive detection cycles, the air conditioner is controlled to enter the first-level defrost mode. When the COP decay rate is greater than the second grade threshold and the COP decay rate is less than or equal to the third grade threshold in multiple consecutive detection cycles, the air conditioner is controlled to enter the second-level defrost mode. When the COP decay rate is greater than the third grade threshold in multiple consecutive detection cycles, and / or the outdoor coil temperature is less than the difference between the outdoor ambient temperature and the frosting temperature threshold, the air conditioner is controlled to enter the reversing defrosting mode. Wherein, the first grading threshold is less than the second grading threshold, and the second grading threshold is less than the third grading threshold.

5. The method according to claim 4, characterized in that, The control of the air conditioner to enter the first-level defrost mode specifically includes: Obtain the current expansion valve opening of the air conditioner; Based on the current expansion valve opening, the COP decay rate, and the first grading threshold, the first target expansion valve opening is calculated, and then the current expansion valve opening is adjusted to increase to the first target expansion valve opening. The target fan speed is calculated based on the indoor fan speed, the COP attenuation rate, and the first grading threshold, and then the indoor fan speed is adjusted to be reduced to the target fan speed.

6. The method according to claim 4, characterized in that, The control of the air conditioner to enter the secondary defrost mode specifically includes: Obtain the initial compressor operating frequency and current expansion valve opening of the air conditioner; The target operating frequency is calculated based on the initial press operating frequency, the COP attenuation rate, and the second grading threshold, and then the initial press operating frequency is adjusted to be reduced to the target operating frequency. Based on the current expansion valve opening, the COP decay rate, and the second grading threshold, the second target expansion valve opening is calculated, and then the current expansion valve opening is adjusted to increase to the second target expansion valve opening.

7. The method according to claim 4, characterized in that, The control of the air conditioner to enter the reversing defrosting mode specifically includes: Adjust the compressor operating frequency of the air conditioner to reduce it to the first operating frequency; Control the four-way valve to switch directions, thereby shutting down the indoor and outdoor fans; The compressor operating frequency of the air conditioner is controlled to operate at a second operating frequency; If the outdoor coil temperature at the current moment is greater than the steady-state temperature threshold and remains so for a first duration, control the compressor operating frequency of the air conditioner to operate at the first operating frequency; If the current outdoor coil temperature is greater than the sum of the outdoor ambient temperature and the defrosting temperature threshold, and this remains for a second duration, control the four-way valve to switch directions. The first operating frequency is less than the second operating frequency.

8. A control system, characterized in that, include: At least one processor; At least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the method as described in any one of claims 1 to 7.

9. An air conditioner, characterized in that, Includes the control system as described in claim 8.

10. A computer-readable storage medium storing a processor-executable program, characterized in that, The processor-executable program implements the method as described in any one of claims 1 to 7 when executed by the processor.

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