A method and device for controlling the frequency of a compressor, and a water heater

Abstract

The application provides a control method and a control device of compressor operation frequency and a water heater. The control method comprises the following steps: calculating the suction pressure attenuation ratio of the compressor; judging the frost degree of the heat exchange equipment according to the suction pressure attenuation ratio of the compressor; and dynamically setting the initial operation frequency of the compressor according to the frost degree of the heat exchange equipment. The control method further comprises the following steps: comparing the initial operation frequency of the compressor with the historical operation frequency of the compressor recorded in a database; and controlling the actual operation frequency of the compressor according to the comparison result. The control method can guarantee the rationality of the actual operation frequency of the compressor, solve the problem of low defrosting efficiency caused by the fixed operation frequency of the compressor during the defrosting process, and improve the energy efficiency.

Description

Technical Field

[0001] This invention relates to the field of air source heat pump water heater technology, specifically to a method and device for controlling the operating frequency of a compressor, and a water heater. Background Technology

[0002] When the water heater operates at low temperatures, frost will form on the evaporator side. When the unit detects that the defrosting conditions are met, it will enter the defrosting process. The four-way valve is energized and reversed, at which point the evaporator side becomes the condenser side, and the high-temperature gas can quickly remove the frost on the evaporator side. Generally, the defrosting compressor of a variable frequency unit operates at a fixed frequency under various operating conditions. This can result in either excessively low defrosting efficiency under certain operating conditions or excessively high defrosting efficiency under other operating conditions, increasing the unit's energy consumption. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a method and device for controlling the operating frequency of a compressor, as well as a water heater, to solve the problem of low defrosting efficiency caused by the fixed frequency of the compressor during the defrosting process in related technologies.

[0004] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0005] According to a first aspect of the present invention, a method for controlling the operating frequency of a compressor is provided, the compressor being connected to a heat exchange device, the compressor being used to provide a defrosting medium to the heat exchange device, the method for controlling the operating frequency of the compressor comprising:

[0006] Calculate the compressor's suction pressure attenuation ratio;

[0007] The degree of frost formation on the heat exchange equipment is determined based on the compressor's suction pressure attenuation ratio, and the initial operating frequency of the compressor during the defrosting process is controlled based on the degree of frost formation on the heat exchange equipment.

[0008] The compressor's initial operating frequency is compared with the historical operating frequency of the compressor recorded in the database, and the actual operating frequency of the compressor is controlled based on the comparison results.

[0009] Preferably, the method for calculating the compressor's suction pressure attenuation ratio includes:

[0010] Obtain the suction pressure P1 after the compressor has stabilized.

[0011] Obtain the suction pressure P2 of the compressor before defrosting of the heat exchange equipment;

[0012] According to the formula Calculate the inspiratory pressure attenuation ratio ΔP.

[0013] Preferably, the method for determining the degree of frosting of the heat exchange equipment based on the compressor's suction pressure attenuation ratio includes:

[0014] Set the first inspiratory pressure attenuation ratio threshold P. o1 The second inspiratory pressure attenuation ratio threshold P o2 The third inspiratory pressure attenuation threshold P o3 And satisfy condition P o1 >P o2 >P o3 ;

[0015] If △P≥P o1 The degree of frosting on the heat exchange equipment is determined to be severe.

[0016] If P o2 ≤△P<P o1 The degree of frosting on the heat exchange equipment is determined to be normal.

[0017] If P o3 ≤△P<P o2 The degree of frost formation on the heat exchange equipment is determined to be slight.

[0018] If △P < P o3 It is determined that the heat exchange equipment is not frosted.

[0019] Preferably, the method for controlling the initial operating frequency of the compressor during defrosting based on the degree of frosting on the heat exchanger includes:

[0020] If the heat exchange equipment is severely frosted, the initial operating frequency of the compressor during the defrosting process is set to a high frequency;

[0021] If the degree of frosting on the heat exchange equipment is normal, the initial operating frequency of the compressor during the defrosting process is set to a medium frequency;

[0022] If the degree of frost formation on the heat exchange equipment is slight, the initial operating frequency of the compressor during the defrosting process is set to a low frequency;

[0023] If the heat exchange equipment is not frosted, the defrosting process will not begin.

[0024] Preferably, the method for controlling the actual operating frequency of the compressor includes:

[0025] Traverse the database to obtain the historical operating frequency of the compressor under the operating condition that is equal to or closest to the current compressor's suction pressure attenuation ratio ΔP.

[0026] If the compressor's initial operating frequency is the same as its historical operating frequency, then the actual operating frequency of the compressor is controlled to be the initial operating frequency.

[0027] If the initial operating frequency of the compressor is different from the historical operating frequency, the actual operating frequency of the compressor is controlled to be a low frequency. It is determined whether ice accumulation occurs in the heat exchange equipment, and the actual operating frequency of the compressor is controlled according to whether ice accumulation occurs in the heat exchange equipment.

[0028] Preferably, the method for determining whether ice buildup occurs in the heat exchange equipment includes:

[0029] The duration T of the frosting cycle of the heat exchanger is continuously acquired. i , among which, T i This represents the time required for the i-th frosting event of the heat exchanger, where i ≥ 1 and is a positive integer;

[0030] According to the formula Calculate the reduction percentage ΔT in the duration of the frost cycle;

[0031] Set the threshold T for reducing the frost cycle duration. o1 ;

[0032] If △T≥T o1 If so, it is determined that ice buildup has occurred in the heat exchange equipment.

[0033] Preferably, the method for controlling the actual operating frequency of the compressor based on whether ice buildup occurs in the heat exchange equipment includes:

[0034] During the i-th defrosting process, the actual operating frequency of the compressor is increased.

[0035] Preferably, the method for controlling the compressor operating frequency further includes:

[0036] If △T <T o1 If so, it is determined that no ice buildup has occurred in the heat exchange equipment;

[0037] During the i-th defrosting process, the actual operating frequency of the compressor is controlled to be the same as the actual operating frequency of the compressor during the (i-1)-th defrosting process.

[0038] According to a second aspect of the present invention, a compressor operating frequency control device is provided, the compressor operating frequency control device comprising:

[0039] The calculation module is used to calculate the compressor's suction pressure attenuation ratio;

[0040] The judgment and control module is used to determine the degree of frosting of the heat exchange equipment based on the compressor's suction pressure attenuation ratio, and to control the initial operating frequency of the compressor during the defrosting process based on the degree of frosting of the heat exchange equipment.

[0041] The comparison control module is used to compare the compressor's initial operating frequency with the compressor's historical operating frequency recorded in the database, and control the compressor's actual operating frequency based on the comparison results.

[0042] According to a third aspect of the present invention, a water heater is provided, the water heater comprising a compressor, characterized in that the water heater further comprises:

[0043] The aforementioned compressor operating frequency control device.

[0044] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0045] The compressor's suction pressure attenuation ratio is calculated, and the degree of frost formation on the heat exchange equipment is determined based on this ratio. The initial operating frequency of the compressor can then be dynamically set according to this frost formation. By comparing the compressor's initial operating frequency with the historical operating frequencies recorded in the database, and based on the comparison results, the actual operating frequency of the compressor can be controlled. This ensures the rationality of the actual operating frequency, solves the problem of low defrosting efficiency caused by a fixed compressor operating frequency during defrosting, and improves energy efficiency. Attached Figure Description

[0046] Figure 1 This is a flowchart illustrating a method for controlling the operating frequency of a compressor according to an exemplary embodiment;

[0047] Figure 2 This is a schematic diagram of a compressor operating frequency control device according to another exemplary embodiment. Detailed Implementation

[0048] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0049] Example 1

[0050] Figure 1 This is a flowchart illustrating a method for controlling the operating frequency of a compressor according to an exemplary embodiment. The compressor is connected to a heat exchange device, and the compressor is used to provide a defrosting medium to the heat exchange device, such as... Figure 1 As shown, the method for controlling the operating frequency of the compressor includes:

[0051] Step S11: Calculate the compressor's suction pressure attenuation ratio;

[0052] Step S12: Determine the degree of frost formation on the heat exchange equipment based on the compressor's suction pressure attenuation ratio, and control the initial operating frequency of the compressor during the defrosting process based on the degree of frost formation on the heat exchange equipment.

[0053] Step S13: Compare the initial operating frequency of the compressor with the historical operating frequency of the compressor recorded in the database, and control the actual operating frequency of the compressor based on the comparison results.

[0054] The technical solution provided in this embodiment calculates the compressor's suction pressure attenuation ratio, determines the degree of frost formation on the heat exchange equipment based on the compressor's suction pressure attenuation ratio, and dynamically sets the compressor's initial operating frequency based on the degree of frost formation on the heat exchange equipment. By comparing the compressor's initial operating frequency with the historical operating frequencies of the compressor recorded in the database, and controlling the compressor's actual operating frequency based on the comparison results, the rationality of the compressor's actual operating frequency can be ensured, solving the problem of low defrosting efficiency caused by a fixed compressor operating frequency during the defrosting process, and improving energy efficiency.

[0055] In practice, the method for calculating the compressor's suction pressure attenuation ratio includes:

[0056] Obtain the suction pressure P1 after the compressor has stabilized.

[0057] Obtain the suction pressure P2 of the compressor before defrosting of the heat exchange equipment;

[0058] According to the formula Calculate the inspiratory pressure attenuation ratio ΔP.

[0059] It should be noted that when the heat exchange equipment is in a frosting condition, the more severe the frosting, the higher the compressor's suction attenuation ratio. Therefore, the degree of frosting of the heat exchange equipment can be determined by the compressor's suction attenuation ratio.

[0060] It is understood that the technical solution provided in this embodiment obtains the suction pressure of the compressor after it has been operating stably and the suction pressure of the compressor before defrosting of the heat exchange equipment, and calculates the suction pressure attenuation ratio. Based on the suction pressure attenuation ratio of the compressor, the degree of frost on the heat exchange equipment can be determined, thereby controlling the operating frequency of the compressor. This solves the problem of low defrosting efficiency caused by the fixed operating frequency of the compressor during the defrosting process and improves energy efficiency.

[0061] In practice, the method for determining the degree of frosting on the heat exchange equipment based on the compressor's suction pressure attenuation ratio includes:

[0062] Set the first inspiratory pressure attenuation ratio threshold P.o1 The second inspiratory pressure attenuation ratio threshold P o2 The third inspiratory pressure attenuation threshold P o3 And satisfy condition P o1 >P o2 >P o3 ;

[0063] If △P≥P o1 The degree of frosting on the heat exchange equipment is determined to be severe.

[0064] If P o2 ≤△P<P o1 The degree of frosting on the heat exchange equipment is determined to be normal.

[0065] If P o3 ≤△P<P o2 The degree of frost formation on the heat exchange equipment is determined to be slight.

[0066] If △P < P o3 It is determined that the heat exchange equipment is not frosted.

[0067] It should be noted that the first, second, and third inhalation pressure attenuation ratio thresholds are empirical values ​​or set according to actual working requirements. For example, if the first inhalation pressure attenuation ratio threshold is set to 20%, the second to 15%, and the third to 10%, then when ΔP ≥ 20%, the heat exchange equipment is considered to have severe frosting; when 15% ≤ ΔP < 20%, the heat exchange equipment is considered to have normal frosting; when 10% ≤ ΔP < 15%, the heat exchange equipment is considered to have slight frosting; and when ΔP < 10%, the heat exchange equipment is considered to have no frosting.

[0068] In practice, the method for controlling the initial operating frequency of the compressor during the defrosting process based on the degree of frosting on the heat exchange equipment includes:

[0069] If the heat exchange equipment is severely frosted, the initial operating frequency of the compressor during the defrosting process is set to a high frequency;

[0070] If the degree of frosting on the heat exchange equipment is normal, the initial operating frequency of the compressor during the defrosting process is set to a medium frequency;

[0071] If the degree of frost formation on the heat exchange equipment is slight, the initial operating frequency of the compressor during the defrosting process is set to a low frequency;

[0072] If the heat exchange equipment is not frosted, the defrosting process will not begin.

[0073] It should be noted that the low, medium, and high frequencies of the compressor are set according to empirical values ​​or equipment parameters to correspond to the frequency range. For example, the compressor's operating frequency is set to be less than 100Hz as low frequency; the compressor's operating frequency is set to be in the frequency range of 100Hz to 2kHz as medium frequency (the medium frequency range includes 100Hz and 2kHz); and the compressor's operating frequency is set to be greater than 2kHz as high frequency.

[0074] It should be noted that if the frost on the heat exchange equipment is severe, setting the initial operating frequency of the compressor during the defrosting process to a high frequency can prevent problems such as low defrosting efficiency or poor defrosting effect. If the frost on the heat exchange equipment is normal, setting the initial operating frequency of the compressor during the defrosting process to a medium frequency can balance defrosting efficiency and unit energy efficiency. If the frost on the heat exchange equipment is slight, setting the initial operating frequency of the compressor during the defrosting process to a low frequency can prevent the compressor operating frequency from exceeding the frequency required for defrosting, thereby improving unit energy efficiency.

[0075] In practice, the method for controlling the actual operating frequency of the compressor includes:

[0076] Traverse the database to obtain the historical operating frequency of the compressor under the operating condition that is equal to or closest to the current compressor's suction pressure attenuation ratio ΔP.

[0077] If the compressor's initial operating frequency is the same as its historical operating frequency, then the actual operating frequency of the compressor is controlled to be the initial operating frequency.

[0078] If the initial operating frequency of the compressor is different from the historical operating frequency, the actual operating frequency of the compressor is controlled to be a low frequency. It is determined whether ice accumulation occurs in the heat exchange equipment, and the actual operating frequency of the compressor is controlled according to whether ice accumulation occurs in the heat exchange equipment.

[0079] It should be noted that the phenomenon of ice buildup refers to the incomplete defrosting of heat exchange equipment, leaving a layer of ice residue on the equipment. After multiple defrosting cycles, the ice layer accumulates and thickens, resulting in a decrease in the heat exchange efficiency of the equipment.

[0080] It should be noted that, in order to ensure the rationality of the compressor's operating frequency, the initial operating frequency of the compressor is compared with the historical operating frequency of the compressor under the same (or closest) operating conditions. If the initial operating frequency of the compressor is different from the historical operating frequency, the actual operating frequency of the compressor is set to a low frequency. Then, each time the heat exchange equipment frosts, it is determined whether ice accumulation occurs, and the defrosting effect of the compressor under low frequency operation is evaluated. In this way, the actual operating frequency of the compressor is further adjusted to ensure the normal operation of the heat exchange equipment and improve energy efficiency.

[0081] In specific practice, the method for determining whether ice accumulation occurs in the heat exchange device includes:

[0082] Continuously obtain the frosting cycle duration T of the heat exchange device i , where T i represents the duration required for the i-th frosting of the heat exchange device, i≥1 and i is a positive integer;

[0083] According to the formula Calculate the reduction ratio △T of the frosting cycle duration;

[0084] Set the reduction ratio threshold T of the frosting cycle duration o1 ;

[0085] If △T≥T o1 , it is determined that ice accumulation occurs in the heat exchange device.

[0086] It should be noted that when ice accumulation occurs in the heat exchange device, it will cause the frosting cycle duration of the heat exchange device to shorten. The reduction ratio threshold of the frosting cycle duration is an empirical value or set according to actual working requirements. For example: set the reduction ratio threshold of the frosting cycle duration to 15%. When △T≥T o1 , it indicates that the duration of the i-th frosting cycle of the heat exchange device is too short, and it is determined that ice accumulation occurs in the heat exchange device.

[0087] In specific practice, the method for controlling the actual operating frequency of the compressor according to whether ice accumulation occurs in the heat exchange device includes:

[0088] During the i-th defrosting process, increase the actual operating frequency of the compressor.

[0089] It should be noted that after determining that ice accumulation occurs in the heat exchange device after the i-th frosting of the heat exchange device, it indicates that the actual operating frequency of the compressor is too low to meet the defrosting requirements of the heat exchange device, and the actual operating frequency of the compressor needs to be increased. For example: after determining that ice accumulation occurs in the heat exchange device after the third frosting of the heat exchange device, during the third defrosting process, increase the compressor frequency from low frequency to medium frequency. If it is determined that ice accumulation occurs in the heat exchange device after the seventh frosting of the heat exchange device, during the seventh defrosting process, increase the compressor frequency from medium frequency to high frequency, so as to remove the ice layer accumulated on the heat exchange device and ensure the stable operation of the heat exchange device.

[0090] In specific practice, the method for controlling the operating frequency of the compressor further includes:

[0091] If △T < To1, it is determined that no ice accumulation occurs in the heat exchange device;

[0092] During the i-th defrosting process, the actual operating frequency of the compressor is controlled to be the same as the actual operating frequency of the compressor during the (i-1)-th defrosting process.

[0093] The technical solution provided in this embodiment ensures stable operation of the heat exchange equipment by using the actual operating frequency of the compressor during the previous defrosting process when no ice buildup occurs in the heat exchange equipment.

[0094] Example 2

[0095] Figure 2 This is a schematic diagram of the structure of a compressor operating frequency control device 100 according to another exemplary embodiment, as shown below. Figure 2 As shown, the compressor operating frequency control device includes:

[0096] Calculation module 101 is used to calculate the compressor's suction pressure attenuation ratio;

[0097] The judgment control module 102 is used to judge the degree of frost on the heat exchange equipment based on the compressor's suction pressure attenuation ratio, and to control the initial operating frequency of the compressor during the defrosting process based on the degree of frost on the heat exchange equipment.

[0098] The comparison control module 103 is used to compare the initial operating frequency of the compressor with the historical operating frequency of the compressor recorded in the database, and control the actual operating frequency of the compressor based on the comparison results.

[0099] It is understood that the technical solution provided in this embodiment, by setting the calculation module 101, the judgment control module 102, and the comparison control module 103, calculates the compressor's suction pressure attenuation ratio, judges the degree of frost on the heat exchange equipment based on the compressor's suction pressure attenuation ratio, and dynamically sets the compressor's initial operating frequency based on the degree of frost on the heat exchange equipment; by comparing the compressor's initial operating frequency with the historical operating frequency of the compressor recorded in the database, and controlling the compressor's actual operating frequency based on the comparison result, the rationality of the compressor's actual operating frequency can be ensured, solving the problem of low defrosting efficiency caused by a fixed compressor operating frequency during the defrosting process, and improving energy efficiency.

[0100] Example 3

[0101] A water heater according to another exemplary embodiment is shown, the water heater including a compressor, characterized in that the water heater further includes:

[0102] The aforementioned compressor operating frequency control device.

[0103] It is understood that the technical solution provided in this embodiment, by setting a control device for the compressor operating frequency in the water heater, calculates the compressor's suction pressure attenuation ratio, determines the degree of frost formation on the heat exchange equipment based on the compressor's suction pressure attenuation ratio, and dynamically sets the compressor's initial operating frequency based on the degree of frost formation on the heat exchange equipment; by comparing the compressor's initial operating frequency with the historical operating frequency of the compressor recorded in the database, and controlling the compressor's actual operating frequency based on the comparison results, the rationality of the compressor's actual operating frequency can be ensured, solving the problem of low defrosting efficiency caused by a fixed compressor operating frequency during defrosting, and improving energy efficiency.

[0104] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0105] If the integrated units in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in the aforementioned computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or 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 one or more computer devices (which may be personal computers, servers, or network devices, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application.

[0106] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0107] In the several embodiments provided in this application, it should be understood that the disclosed client can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, indirect coupling or communication connection between units or modules, and may be electrical or other forms.

[0108] The units described as separate components may or may not be physically separate. 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 units can be selected to achieve the purpose of this embodiment according to actual needs.

[0109] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0110] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for controlling the operating frequency of a compressor, wherein the compressor is connected to a heat exchange device, and the compressor is used to provide a defrosting medium to the heat exchange device, characterized in that, The method for controlling the operating frequency of the compressor includes: Calculate the compressor's suction pressure attenuation ratio; The degree of frost formation on the heat exchange equipment is determined based on the compressor's suction pressure attenuation ratio, and the initial operating frequency of the compressor during the defrosting process is controlled based on the degree of frost formation on the heat exchange equipment. The compressor's initial operating frequency is compared with the historical operating frequency of the compressor recorded in the database, and the actual operating frequency of the compressor is controlled based on the comparison results. The method for controlling the actual operating frequency of the compressor includes: Traverse the database to obtain the historical operating frequency of the compressor under the operating condition that is equal to or closest to the current compressor's suction pressure attenuation ratio ΔP. If the compressor's initial operating frequency is the same as its historical operating frequency, then the actual operating frequency of the compressor is controlled to be the initial operating frequency. If the initial operating frequency of the compressor is different from the historical operating frequency, the actual operating frequency of the compressor is controlled to be a low frequency. It is determined whether ice accumulation occurs in the heat exchange equipment, and the actual operating frequency of the compressor is controlled according to whether ice accumulation occurs in the heat exchange equipment.

2. The method for controlling the operating frequency of a compressor according to claim 1, characterized in that, The method for calculating the compressor's suction pressure attenuation ratio includes: Obtain the suction pressure P1 after the compressor has stabilized. Obtain the suction pressure P2 of the compressor before defrosting of the heat exchange equipment; According to the formula Calculate the inspiratory pressure attenuation ratio ΔP.

3. The method for controlling the operating frequency of a compressor according to claim 2, characterized in that, The method for determining the degree of frosting on the heat exchange equipment based on the compressor's suction pressure attenuation ratio includes: Set the first inspiratory pressure attenuation ratio threshold P. o1 The second inspiratory pressure attenuation ratio threshold P o2 The third inspiratory pressure attenuation ratio threshold P o3 And satisfy condition P o1 >P o2 >P o3 ; If △P≥P o1 The degree of frosting on the heat exchange equipment is determined to be severe. If P o2 ≤△P<P o1 The degree of frosting on the heat exchange equipment is determined to be normal. If P o3 ≤△P<P o2 The degree of frost formation on the heat exchange equipment is determined to be slight. If △P < P o3 It is determined that the heat exchange equipment is not frosted.

4. The method for controlling the operating frequency of a compressor according to claim 3, characterized in that, The method for controlling the initial operating frequency of the compressor during defrosting based on the degree of frosting on the heat exchange equipment includes: If the heat exchange equipment is severely frosted, the initial operating frequency of the compressor during the defrosting process is set to a high frequency; If the degree of frosting on the heat exchange equipment is normal, the initial operating frequency of the compressor during the defrosting process is set to a medium frequency; If the degree of frost formation on the heat exchange equipment is slight, the initial operating frequency of the compressor during the defrosting process is set to a low frequency; If the heat exchange equipment is not frosted, the defrosting process will not begin.

5. The method for controlling the operating frequency of a compressor according to claim 1, characterized in that, The method for determining whether ice buildup occurs in the heat exchange equipment includes: The duration T of the frosting cycle of the heat exchanger is continuously acquired. i , among which, T i This represents the time required for the i-th frosting event of the heat exchanger, where i ≥ 1 and is a positive integer; According to the formula Calculate the reduction rate ΔT in the duration of the frost cycle; Set the threshold T for reducing the frost cycle duration. o1 ; If △T≥T o1 If so, it is determined that ice buildup has occurred in the heat exchange equipment.

6. The method for controlling the operating frequency of a compressor according to claim 5, characterized in that, The method for controlling the actual operating frequency of the compressor based on whether ice buildup occurs in the heat exchange equipment includes: During the i-th defrosting process, the actual operating frequency of the compressor is increased.

7. The method for controlling the operating frequency of a compressor according to claim 5, characterized in that, The method for controlling the operating frequency of the compressor also includes: If △T <T o1 If so, it is determined that no ice buildup has occurred in the heat exchange equipment; During the i-th defrosting process, the actual operating frequency of the compressor is controlled to be the same as the actual operating frequency of the compressor during the (i-1)-th defrosting process.

8. A control device for the operating frequency of a compressor, characterized in that, The compressor operating frequency control method according to any one of claims 1-7, wherein the compressor operating frequency control device comprises: The calculation module is used to calculate the compressor's suction pressure attenuation ratio; The judgment and control module is used to determine the degree of frosting of the heat exchange equipment based on the compressor's suction pressure attenuation ratio, and to control the initial operating frequency of the compressor during the defrosting process based on the degree of frosting of the heat exchange equipment. The comparison control module is used to compare the compressor's initial operating frequency with the compressor's historical operating frequency recorded in the database, and control the compressor's actual operating frequency based on the comparison results.

9. A water heater, the water heater comprising a compressor, characterized in that, The water heater also includes: The compressor operating frequency control device according to claim 8.

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