A defrosting method, device and storage medium of an air source heat pump unit

Abstract

A defrosting method and device for an air source heat pump unit and a storage medium, wherein sensor data is received, the sensor data including: ambient temperature, outlet water temperature and pressure data; the pressure data including low-pressure side data and high-pressure side data; whether the evaporator of the air source heat pump unit meets defrosting conditions is determined based on the sensor data and recorded running time of the air source heat pump unit; and after it is determined that the evaporator meets defrosting conditions, defrosting operation is performed on the evaporator, so that the air source heat pump unit can still be switched to a defrosting mode in the case of defrosting temperature sensor abnormality.

Description

Technical Field

[0001] This article relates to heat pump control technology, and in particular to a defrosting method, device and storage medium for an air source heat pump unit. Background Technology

[0002] A heat pump unit is a device that uses the principle of heat pumps to convert energy. It transfers heat from a low-temperature heat source to a high-temperature heat sink to meet heating or cooling needs. The core function of a heat pump unit is to absorb heat from a low-temperature environment and release it in a high-temperature environment through the circulation of refrigerant in components such as the evaporator, compressor, condenser, and expansion valve. Depending on the type of low-temperature heat source, common heat pump units include air-source heat pump units, water-source heat pump units, and ground-source heat pump units.

[0003] Frosting is a common phenomenon in the operation of air source heat pump units during winter. It reduces the heat exchange area of ​​the evaporator in the air source heat pump unit and reduces the heat exchange efficiency. In severe cases, it can cause the air source heat pump unit to malfunction.

[0004] To address the frosting issue, air source heat pump units are typically equipped with an automatic defrosting function. A defrosting temperature sensor detects the surface temperature of the evaporator; when the detected surface temperature is lower than a preset temperature, the air source heat pump unit automatically switches to defrosting mode. However, if the defrosting temperature sensor malfunctions, it will affect the defrosting effect and impact the user experience. Summary of the Invention

[0005] This application provides a defrosting method, apparatus, and storage medium for an air source heat pump unit, which can still ensure that the air source heat pump unit can switch to defrosting mode even when the defrosting temperature sensor is abnormal.

[0006] The defrosting method for air source heat pump units provided in this application includes:

[0007] Receive sensor data, which includes: ambient temperature, outlet water temperature, and pressure data; the pressure data includes low-pressure side data and high-pressure side data.

[0008] Based on the sensor data and the recorded running time of the air source heat pump unit, it is determined whether the evaporator of the air source heat pump unit meets the defrosting conditions.

[0009] After determining that the evaporator meets the defrosting conditions, a defrosting operation is performed on the evaporator.

[0010] Another defrosting method for an air source heat pump unit provided in this application embodiment includes:

[0011] Determine if the defrost temperature sensor installed in the air source heat pump unit is working properly;

[0012] When the defrost temperature sensor is working normally, the evaporator of the air source heat pump unit is determined to meet the defrost conditions based on the temperature data from the defrost temperature sensor. After determining that the evaporator meets the defrost conditions based on the temperature data, the defrost operation is performed on the evaporator.

[0013] If the defrost temperature sensor fails to function properly, perform the defrost method as described in the previous embodiment.

[0014] This application provides a non-transient computer-readable storage medium that stores one or more program instructions, which can be executed by one or more processors to implement the defrosting method for air source heat pump units as described in the previous embodiment.

[0015] This application provides a defrosting device for an air source heat pump unit, the device comprising:

[0016] Memory is configured to store computer program instructions that can be executed on a processor;

[0017] The processor is configured to execute the computer program instructions to implement the defrosting method for the air source heat pump unit as described in the previous embodiment.

[0018] The technical solution described in this application uses ambient temperature, outlet water temperature, pressure data, and the running time of the air source heat pump unit to determine defrosting conditions, providing a new approach to defrosting judgment. In particular, when the existing defrosting temperature sensor of the air source heat pump unit is abnormal, it can ensure that the air source heat pump unit can still perform defrosting operations normally.

[0019] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application can be realized and obtained by means of the solutions described in the description and the accompanying drawings. Attached Figure Description

[0020] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0021] Figure 1 A flowchart illustrating a defrosting method for an air source heat pump unit provided in this application embodiment;

[0022] Figure 2A modular diagram of an air source heat pump unit provided in this application embodiment;

[0023] Figure 3 A flowchart illustrating a method for stopping defrosting an air source heat pump unit, as provided in this application embodiment;

[0024] Figure 4 A flowchart illustrating another defrosting method for an air source heat pump unit provided in this application embodiment;

[0025] Figure 5 A flowchart illustrating a defrosting method for an air-source heat pump unit, as an application example of this application;

[0026] Figure 6 A flowchart illustrating another defrosting method for an air source heat pump unit provided in this application embodiment;

[0027] Figure 7 A module diagram of a defrosting device for an air source heat pump unit provided in an embodiment of this application. Detailed Implementation

[0028] This application describes several embodiments, but these descriptions are exemplary and not restrictive, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0029] This application includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this application can also be combined with any conventional features or elements to form unique inventive solutions. Any feature or element of any embodiment can also be combined with features or elements from other inventive solutions to form another unique inventive solution. Therefore, it should be understood that any feature shown and / or discussed in this application can be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes can be made within the scope of the appended claims.

[0030] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that it does not depend on such a specific order. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims concerning the method and / or process should not be limited to the steps performed in the written order, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments of this application.

[0031] This application provides a defrosting method for an air source heat pump unit, such as... Figure 1 As shown, the method includes:

[0032] Step S101 receives sensor data; the sensor data comes from sensors installed in the air source heat pump unit; the sensor data includes: ambient temperature, outlet water temperature and pressure data; the pressure data includes: low-pressure side data and high-pressure side data, the low-pressure side data reflects the pressure level of the refrigerant in the evaporator, and the high-pressure side data reflects the pressure level of the refrigerant in the condenser.

[0033] Figure 2 This is a modular diagram of an air source heat pump unit. The diagram shows the locations of various sensors, where T4 represents the ambient temperature, monitored by an ambient temperature sensor; T3 is the evaporator surface temperature (i.e., defrost temperature), monitored by a defrost temperature sensor; T... wout For water outlet temperature, T win This refers to the inlet water temperature. The working process of an air source heat pump unit mainly consists of: compression, condensation, throttling, and evaporation. During compression, the refrigerant vapor is compressed from a low-pressure state to a high-pressure state by the compressor, significantly increasing both the temperature and pressure of the refrigerant. During condensation, the high-temperature, high-pressure refrigerant vapor enters the condenser (also known as the indoor heat exchanger) and condenses into a high-pressure liquid state, releasing energy (usually heat to the room in heating mode). During throttling, the condensed high-pressure liquid refrigerant passes through an expansion valve (or capillary tube) and experiences pressure reduction. During throttling, some of the refrigerant evaporates, forming a gas-liquid mixture, and its temperature decreases accordingly. During evaporation, the low-pressure gas-liquid mixture enters the evaporator (outdoor heat exchanger), absorbs heat from the air, and evaporates, returning to a vapor state. During evaporation, the heat absorbed by the refrigerant raises its temperature, completing one cycle.

[0034] Step S102 determines whether the evaporator of the air source heat pump unit meets the defrosting conditions based on the sensor data and the recorded running time of the air source heat pump unit; the running time, that is, the continuous running time of the compressor, can be obtained from the main board of the outdoor unit of the air source heat pump unit.

[0035] Step S103: After determining that the evaporator meets the defrosting conditions, perform a defrosting operation on the evaporator.

[0036] The technical solution described in this application uses ambient temperature, outlet water temperature, pressure data, and the running time of the air source heat pump unit to determine defrosting conditions, providing a new approach to defrosting judgment. In particular, when the existing defrosting temperature sensor of the air source heat pump unit is abnormal, it can ensure that the air source heat pump unit can still perform defrosting operations normally.

[0037] In an exemplary embodiment, determining whether the evaporator of the air source heat pump unit meets the defrosting conditions based on the sensor data and the recorded operating time of the air source heat pump unit includes: determining a preset ambient temperature range in which the ambient temperature is located; and determining whether the evaporator meets the defrosting conditions corresponding to the preset ambient temperature range in which the ambient temperature is located, at least based on the operating time and the evaporation temperature calculated based on the low-pressure side data; wherein the defrosting conditions corresponding to the preset ambient temperature range in which the ambient temperature is located include the conditions that the operating time and the evaporation temperature must each meet.

[0038] The evaporation temperature is affected by the low-pressure side data in the pressure data. The lower the low-pressure, the lower the corresponding evaporation temperature; the higher the low-pressure, the higher the corresponding evaporation temperature. When the evaporation temperature decreases, the temperature of the evaporator surface also decreases. The lower the evaporation temperature, the easier it is for frost to form on the evaporator surface, and frost further lowers the temperature of the evaporator surface. Therefore, using the evaporation temperature as a condition for defrosting is effective.

[0039] In one exemplary embodiment, there may be multiple preset ambient temperature ranges, and these multiple preset ambient temperature ranges do not overlap; for example, the multiple preset ambient temperature ranges include a first ambient temperature range, a second ambient temperature range, and so on. a2 ,T a1 ), the third ambient temperature range [T a3 ,T a2 The first ambient temperature range is greater than or equal to T. a1 The fourth ambient temperature range is less than T. a3 The interval, T a3 <T a2 <T a1 Where -2.5℃≤Ta1 ≤-1.5℃, -6℃≤T a2 ≤-4℃, -11℃≤T a3 ≤-9℃; for example, the first ambient temperature range is greater than or equal to -2℃, the second ambient temperature range is [-5℃, -2℃), the third ambient temperature range is [-10℃, -5℃), and the fourth ambient temperature range is less than -10℃.

[0040] Different preset ambient temperature ranges correspond to different defrosting conditions, which include at least one of the following: different running lengths and different evaporation temperatures.

[0041] In an exemplary embodiment, among the defrosting conditions corresponding to each of the plurality of preset ambient temperature ranges, the evaporation temperature needs to meet the following conditions: the evaporation temperature must be less than or equal to a preset maximum evaporation temperature. Furthermore, the higher the ambient temperature range, the higher the maximum evaporation temperature in the corresponding evaporation temperature condition. For example, the first ambient temperature range is a range greater than or equal to -2°C, and the maximum evaporation temperature in its corresponding defrosting conditions is T. e1 The second ambient temperature range is [-5℃, -2℃), and the maximum evaporation temperature in the corresponding defrosting conditions is T. e2 The third ambient temperature range is [-10℃, -5℃), and the maximum evaporation temperature in the corresponding defrosting conditions is T. e3 The fourth ambient temperature range is below -10℃, and the maximum evaporation temperature in the corresponding defrosting conditions is T. e4 Then T e4 <T e3 <T e2 <T e1。 For example, -12℃≤T e1 ≤-8℃, -17℃≤T e2 ≤-13℃, -22℃≤T e3 ≤-18℃, -27℃≤T e4 ≤-23℃. For example, the maximum evaporation temperature in the defrosting conditions corresponding to the first ambient temperature range greater than or equal to -2℃ is -10℃, the maximum evaporation temperature in the defrosting conditions corresponding to the second ambient temperature range [-5℃, -2℃) is -15℃, the maximum evaporation temperature in the defrosting conditions corresponding to the third ambient temperature range [-10℃, -5℃) is -20℃, and the maximum evaporation temperature in the defrosting conditions corresponding to the fourth ambient temperature range less than -10℃ is -25℃.

[0042] In another exemplary embodiment, the defrosting conditions corresponding to the first ambient temperature range require the evaporation temperature to meet the following conditions: the time required for the evaporation temperature to decrease by 1°C is within a preset time range. For the defrosting conditions corresponding to the second, third, and fourth ambient temperature ranges, the evaporation temperature must be less than or equal to a preset maximum evaporation temperature. Furthermore, the higher the ambient temperature range, the higher the maximum evaporation temperature required for the corresponding evaporation temperature. In this embodiment, for the first ambient temperature range, the evaporation temperature condition is determined by the time required for the evaporation temperature to decrease by 1°C. This time reflects the rate of temperature decrease, which is related to the degree of frost formation on the evaporator. When the evaporation temperature decreases rapidly, it means that the evaporator surface is more likely to reach or fall below the dew point temperature, thereby accelerating the frost formation process.

[0043] In an exemplary embodiment, the second ambient temperature range, the third ambient temperature range, and the fourth ambient temperature range may each correspond to multiple defrosting conditions; each defrosting condition corresponding to the second ambient temperature range, the third ambient temperature range, and the fourth ambient temperature range also includes a condition that the outlet water temperature needs to meet, and the conditions that the outlet water temperature needs to meet in different defrosting conditions corresponding to the same ambient temperature range are also different. For example, the outlet water temperature ranges in different defrosting conditions corresponding to the same ambient temperature range do not overlap.

[0044] In each defrosting condition corresponding to the second, third, and fourth ambient temperature ranges, the outlet water temperature must be within a preset outlet water temperature range, the running time must be greater than or equal to a preset minimum running time, and the evaporation temperature must be less than or equal to a preset maximum evaporation temperature.

[0045] The conditions that the outlet water temperature needs to meet and the conditions that the running time needs to meet in any two defrosting conditions corresponding to the second, third, and fourth ambient temperature ranges are related: if the outlet water temperature in the outlet water temperature range of the first defrosting condition is higher than the outlet water temperature in the outlet water temperature range of the second defrosting condition, then the minimum running time in the first defrosting condition is greater than the minimum running time in the second defrosting condition.

[0046] For example, multiple preset ambient temperature ranges include the first ambient temperature range and the second ambient temperature range as described above [T]. a2 ,T a1 ), the third ambient temperature range [T a3 ,Ta2 The first ambient temperature range is greater than or equal to T. a1 The fourth ambient temperature range is less than T. a3 The interval, T a3 <T a2 <T a1 And -2.5℃≤T a1 ≤-1.5℃, -6℃≤T a2 ≤-4℃, -11℃≤T a3 At temperatures ≤-9℃:

[0047] The first ambient temperature range corresponds to the defrosting condition: C 11 C 11 The outlet water temperature range is not limited, and the minimum operating time is t. 11 The maximum evaporation temperature is T. e1 32min≤t 11 ≤37min, -12℃≤T e1 ≤-8℃; or, the first ambient temperature range corresponds to defrosting condition C. 12 C 12 The minimum running time is t 11 C 12 The outlet water temperature range is not limited, 33min≤t 11 ≤37min, the time for each 1℃ decrease in evaporation temperature is within the preset time range [50s, 10min];

[0048] The second ambient temperature range can correspond to three defrosting conditions: C 21 C 22 and C 23 C 21 The outlet water temperature range is greater than or equal to T. wout21 The minimum running time is t for the interval. 21 The maximum evaporation temperature is T. e2 C 22 The outlet water temperature range is (T) wout22 ,T wout21 The minimum running time is t. 22 The maximum evaporation temperature is T. e2 C 23 The outlet water temperature range is less than or equal to T. wout22 The minimum running time is t for the interval. 23 The maximum evaporation temperature is T. e2 Among them, 30℃≤T wout21 ≤36℃, 22℃≤T wout22 ≤28℃, 38min≤t 21≤42min, 33min≤t 22 ≤37min, 28min≤t 23 ≤32min, -17℃≤T e2 ≤-13℃;

[0049] The third ambient temperature range corresponds to three defrosting conditions: C 31 C 32 and C 33 In the middle, C 31 The outlet water temperature range is greater than or equal to T. wout31 The minimum running time is t for the interval. 31 The maximum evaporation temperature is T. e3 C 32 The outlet water temperature range is (T) wout32 ,T wout31 The minimum running time is t. 32 The maximum evaporation temperature is T. e3 C 33 The outlet water temperature range is less than or equal to T. wout32 The minimum running time is t for the interval. 33 The maximum evaporation temperature is T. e3 Among them, 30℃≤T wout31 ≤36℃, 22℃≤T wout32 ≤28℃, 62min≤t 31 ≤68min, 52min≤t 32 ≤58min, 42min≤t 33 ≤48min, -22℃≤T e3 ≤-18℃;

[0050] The fourth ambient temperature range corresponds to three defrosting conditions: C 41 C 42 and C 43 In the middle, C 41 The outlet water temperature range is greater than or equal to T. wout41 The minimum running time is t for the interval. 41 The maximum evaporation temperature is T. e4 C 42 The outlet water temperature range is (T) wout42 ,T wout41 The minimum running time is t. 42 The maximum evaporation temperature is T. e4 C 43 The outlet water temperature range is less than or equal to T. wout42 The minimum running time is t for the interval. 43 The maximum evaporation temperature is T. e4 Among them, 30℃≤T wout41≤36℃, 22℃≤T wout42 ≤28℃, 130min≤t 41 ≤150min, 110min≤t 42 ≤130min, 90min≤t 43 ≤110min, -27℃≤T e4 ≤-23℃.

[0051] After determining that the evaporator of the air source heat pump unit meets the defrosting conditions according to the method described in the above embodiments, the air source heat pump unit can perform a defrosting operation on the evaporator according to the existing defrosting logic.

[0052] This application also provides a method for stopping defrosting an air source heat pump unit, such as... Figure 3 As shown, the method includes:

[0053] In step S301, during the defrosting process of the evaporator of the air source heat pump unit, the defrosting duration, the received pressure data, and the received outlet water temperature are recorded. The recorded data is also used to periodically determine whether the evaporator of the air source heat pump unit meets the conditions for stopping defrosting. The received pressure data includes low-pressure side data and high-pressure side data. The low-pressure side data reflects the pressure level of the refrigerant in the evaporator, and the high-pressure side data reflects the pressure level of the refrigerant in the condenser.

[0054] Step S302: After determining that the evaporator meets the defrosting stop condition, stop performing the defrosting operation on the evaporator.

[0055] The technical solution described in this application uses defrosting time, received pressure data, and received outlet water temperature to determine the conditions for stopping defrosting, providing a new approach to stopping defrosting. Especially when the existing defrosting sensor of the air source heat pump unit is abnormal, it can ensure that the air source heat pump unit can still perform the defrosting stop operation normally.

[0056] In an exemplary embodiment, the defrosting operation of the evaporator of the air source heat pump unit can be performed using a defrosting method as described in any of the preceding embodiments, such as... Figure 4 As shown, after step S103, step S104 is also included, in which, during the defrosting operation of the evaporator, it is periodically determined whether the evaporator of the air source heat pump unit meets the defrosting stop condition based on the recorded defrosting duration, received pressure data and received outlet water temperature; after determining that the evaporator meets the defrosting stop condition, the defrosting operation is stopped.

[0057] In an exemplary embodiment, the periodic determination of whether the evaporator of the air source heat pump unit still meets the conditions for stopping defrosting, based on the recorded defrosting duration, received pressure data, and received outlet water temperature, includes:

[0058] If any one of the following conditions is met, the evaporator is determined to meet the defrosting stop condition:

[0059] If the recorded defrosting time is greater than or equal to the preset defrosting time threshold, then the defrosting stop condition is determined to be met. For example, if the recorded defrosting time is greater than or equal to the preset defrosting time threshold of 5 minutes, then the defrosting stop condition is determined to be met.

[0060] If the received current outlet water temperature is less than the preset outlet water temperature threshold and the duration is greater than or equal to the preset first time threshold, then the defrosting stop condition is determined to be met. For example, if the received current outlet water temperature is less than 7℃ and the duration is greater than 5s, then the defrosting stop condition is determined to be met.

[0061] If the high-pressure side data is greater than or equal to the preset high-pressure threshold when entering the defrosting operation, and if the high-pressure side data is detected to be continuously greater than or equal to the preset high-pressure threshold and the duration reaches the second time threshold during the defrosting operation, then it is determined that the defrosting stop condition is met.

[0062] If the high-pressure side data at the start of the defrosting operation is less than the preset high-pressure threshold, and if the high-pressure side data during the defrosting operation is detected to be greater than or equal to the high-pressure side data at the start of the defrosting operation and the duration reaches a third time threshold, then it is determined that the defrosting stop condition is met; for example, the third time threshold is greater than the second time threshold.

[0063] Taking refrigerant R290 as an example, a preset high-pressure threshold of 2.5 MPa is set, corresponding to an outlet water temperature of approximately 68°C. When the high-pressure side data at the start of defrosting is equal to or greater than the preset high-pressure threshold of 2.5 MPa, it means that the high-pressure limit (e.g., 3.5 MPa) is close, and the outlet water temperature at the start of defrosting has reached 68°C or even higher. Due to the high outlet water temperature at the start of defrosting, the possibility of severe frost formation is low, and defrosting can be stopped as soon as possible to ensure the safety and stability of the heat pump unit operating under high-temperature defrosting conditions. When the high-pressure side data at the start of defrosting is less than the preset high-pressure threshold of 2.5 MPa, it means that the high-pressure limit (e.g., 3.5 MPa) is far, and the defrosting time can be appropriately extended to ensure the defrosting effect. Table 1 shows the defrosting stop conditions determined based on the high-pressure side data when using refrigerant R290.

[0064]

[0065] Table 1

[0066] Below is an application example of a defrosting method for an air source heat pump unit, such as... Figure 5 As shown.

[0067] After the air source heat pump unit is turned on, check whether the defrost temperature sensor is abnormal.

[0068] If the defrost temperature sensor does not malfunction, the defrost operation is performed and stopped based on the temperature detected by the defrost temperature sensor.

[0069] If the defrost temperature sensor malfunctions, a defrost operation is performed according to the method described in the embodiments of this application. This involves determining whether the evaporator of the air source heat pump unit meets the defrost conditions based on the ambient temperature detected by the ambient temperature sensor, the outlet water temperature detected by the outlet water temperature sensor, the low-pressure side data detected by the pressure sensor, and the operating time of the air source heat pump unit. This includes:

[0070] Defrosting conditions are determined to be met when the ambient temperature detected by the ambient temperature sensor is within a preset first ambient temperature range (i.e., greater than or equal to -2°C), the operating time is greater than or equal to 35 minutes, and the evaporation temperature is less than or equal to -10°C. Alternatively, defrosting conditions are determined to be met when the ambient temperature detected by the ambient temperature sensor is within the preset first ambient temperature range, the operating time is greater than or equal to 35 minutes, and the time required for the evaporation temperature to decrease by 1°C is between 50 seconds and 10 minutes. When the evaporation temperature drops rapidly, it accelerates the condensation of water vapor in the air onto the evaporator surface, which in turn accelerates the rate at which the evaporator surface temperature decreases.

[0071] If the ambient temperature detected by the ambient temperature sensor is less than -2℃, the water outlet temperature will continue to be determined.

[0072] The system determines that the ambient temperature detected by the ambient temperature sensor is within the preset second ambient temperature range [-5℃, -2℃], the detected outlet water temperature is greater than or equal to 33℃, the running time is greater than or equal to 40 minutes, and the detected evaporation temperature T... e If the temperature is less than or equal to -15℃, then the defrosting conditions are met.

[0073] If the ambient temperature detected by the ambient temperature sensor is within the preset second ambient temperature range [-5℃, -2℃), the detected outlet water temperature is within the range [25℃, 33℃), the running time is greater than or equal to 35 minutes, and the detected evaporation temperature T e If the temperature is less than or equal to -15℃, then the defrosting conditions are met.

[0074] If the ambient temperature detected by the ambient temperature sensor is within the preset second ambient temperature range [-5℃, -2℃], the detected outlet water temperature is within the range of less than 25℃, the running time is greater than or equal to 30 minutes, and the detected evaporation temperature T e If the temperature is less than or equal to -15℃, then the defrosting conditions are met.

[0075] Table 2 provides examples of defrosting conditions when the ambient temperature detected by the ambient temperature sensor is within a preset second ambient temperature range [-5℃, -2℃]. In the table, T... wout T1 represents the detected outlet water temperature, and T4 represents the detected ambient temperature. Within the same ambient temperature range, since the pressure on the high-pressure side is directly proportional to the condensing temperature, the higher the condenser outlet water temperature, the higher the pressure on the high-pressure side, and the pressure on the low-pressure side also increases accordingly. This, in turn, increases the evaporation temperature of the evaporator, making frosting less likely. Therefore, the operating time can be appropriately extended.

[0076]

[0077] Table 2

[0078] The system determines that the ambient temperature detected by the ambient temperature sensor is within the preset third ambient temperature range [-10℃, -5℃], the detected outlet water temperature is greater than or equal to 33℃, the running time is greater than or equal to 65 minutes, and the detected evaporation temperature T... e If the temperature is less than or equal to -20℃, then the defrosting conditions are met.

[0079] If the ambient temperature detected by the ambient temperature sensor is within the preset third ambient temperature range [-10℃, -5℃), the detected outlet water temperature is within the range [25℃, 33℃), the running time is greater than or equal to 55 minutes, and the detected evaporation temperature T... e If the temperature is less than or equal to -20℃, then the defrosting conditions are met.

[0080] If the ambient temperature detected by the ambient temperature sensor is within the preset third ambient temperature range [-10℃, -5℃], the detected outlet water temperature is within the range of less than 25℃, the running time is greater than or equal to 45 minutes, and the detected evaporation temperature T e If the temperature is less than or equal to -20℃, then the defrosting conditions are met.

[0081] Table 3 provides examples of defrosting conditions corresponding to the ambient temperature being within the preset third ambient temperature range [-10℃, -5℃].

[0082]

[0083] Table 3

[0084] By comparing Tables 2 and 3, when the ambient temperature is in the preset third ambient temperature range [-10℃, -5℃), the evaporation temperature corresponding to frost is lower than that in the preset second ambient temperature range [-5℃, -2℃]. Since the lower the ambient temperature, the less likely the water vapor in the air is to reach the dew point temperature, the less likely it is to frost, so the operating time can be appropriately extended.

[0085] The system determines that the ambient temperature detected by the ambient temperature sensor is within the preset fourth ambient temperature range of less than -10℃, the detected outlet water temperature is greater than or equal to 33℃, the operating time is greater than or equal to 140 minutes, and the detected evaporation temperature T... e If the temperature is less than or equal to -25℃, then the defrosting conditions are met.

[0086] If the ambient temperature detected by the ambient temperature sensor is within the preset fourth ambient temperature range of less than -10℃, the detected outlet water temperature is within the range [25℃, 33℃), the running time is greater than or equal to 120 minutes, and the detected evaporation temperature T e If the temperature is less than or equal to -25℃, then the defrosting conditions are met.

[0087] If the ambient temperature detected by the ambient temperature sensor is within the preset fourth ambient temperature range of less than -10℃, the detected outlet water temperature is within the range of less than 25℃, the running time is greater than or equal to 100 minutes, and the detected evaporation temperature T e If the temperature is less than or equal to -25℃, then the defrosting conditions are met.

[0088] Table 4 provides examples of defrosting conditions corresponding to a preset fourth ambient temperature range where the ambient temperature is less than -10°C.

[0089]

[0090] Table 4

[0091] After the defrosting conditions are met, the air source heat pump unit can perform a defrosting operation on the evaporator according to the existing defrosting logic.

[0092] During the defrosting operation of an air source heat pump unit, the defrosting stop condition is met and the defrosting operation is terminated if any of the following conditions are met.

[0093] The conditions include: defrosting time greater than or equal to 5 minutes; high-pressure side data Pc0 at the start of defrosting operation greater than or equal to 2.5 MPa, and during defrosting, high-pressure side data Pc ≥ 2.5 MPa is detected and lasts for 10 seconds; high-pressure side data Pc0 at the start of defrosting operation less than 2.5 MPa, and during defrosting, high-pressure side data Pc ≥ high-pressure side data Pc0 at the start of defrosting is detected and lasts for 20 seconds; and the received current outlet water temperature is less than 7°C and lasts for more than 5 seconds.

[0094] Once the conditions for stopping defrosting are met, the air source heat pump unit will cease defrosting operations.

[0095] This application also provides a defrosting method for an air source heat pump unit, such as... Figure 6 As shown, the method includes:

[0096] Step S601 detects the working status of the defrost temperature sensor installed in the air source heat pump unit.

[0097] Step S602 determines whether the defrost temperature sensor is working properly based on the detected working status of the defrost temperature sensor; if the defrost temperature sensor is working properly, proceed to step S603; if the defrost temperature sensor is not working properly, proceed to step S604.

[0098] Step S603 determines whether the evaporator of the air source heat pump unit meets the defrosting conditions based on the temperature data from the defrosting sensor. After determining that the evaporator meets the defrosting conditions based on the temperature data, the defrosting operation is performed on the evaporator, and the process ends.

[0099] Step S604: Perform the defrosting operation according to the defrosting method described in the previous embodiment, and the process ends.

[0100] The technical solution described in this application can achieve defrosting operation whether the existing defrosting sensor of the air source heat pump unit is normal or abnormal, thus ensuring the normal operation of the air source heat pump unit.

[0101] This application also provides a non-transient computer-readable storage medium storing one or more program instructions that can be executed by one or more processors to implement the defrosting method for air source heat pump units as described in any of the preceding embodiments.

[0102] This application also provides a defrosting device for an air source heat pump unit, such as... Figure 7As shown, the device includes: a memory 701 configured to store computer program instructions executable on a processor 702; and a processor 702 configured to execute the computer program instructions to implement the defrosting method for an air source heat pump unit as described in any of the preceding embodiments.

[0103] It will be understood by those skilled in the art that all or some of the steps, systems, or apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit (ASIC). Such software may be distributed on a computer-readable medium, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term "computer storage medium" 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 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 can be accessed by a computer. Furthermore, it is well known to those skilled in the art that 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.

Claims

1. A defrosting method for an air source heat pump unit, comprising: Receive sensor data, which includes: ambient temperature, outlet water temperature, and pressure data; the pressure data includes low-pressure side data and high-pressure side data. Based on the sensor data and the recorded operating time of the air source heat pump unit, it is determined whether the evaporator of the air source heat pump unit meets the defrosting conditions. After determining that the evaporator meets the defrosting conditions, a defrosting operation is performed on the evaporator.

2. The defrosting method according to claim 1, characterized in that, The step of determining whether the evaporator of the air source heat pump unit meets the defrosting conditions based on the sensor data and the recorded operating time of the air source heat pump unit includes: Determine the preset ambient temperature range in which the ambient temperature falls; Based at least on the runtime and the evaporation temperature calculated from the low-pressure side data, determine whether the evaporator meets the defrosting conditions corresponding to the preset ambient temperature range where the ambient temperature is located. The defrosting conditions include the conditions that the running time and the evaporation temperature must each meet.

3. The defrosting method according to claim 2, characterized in that, There are multiple preset ambient temperature ranges, which do not overlap, and different preset ambient temperature ranges correspond to different defrosting conditions.

4. The defrosting method according to claim 3, characterized in that, The plurality of preset ambient temperature ranges include a first ambient temperature range and a second ambient temperature range [T]. a2 ,T a1 ), the third ambient temperature range [T a3 ,T a2 The first ambient temperature range is greater than or equal to T. a1 The fourth ambient temperature range is less than T. a3 The interval, T a3 <T a2 <T a1 ; Where -2.5℃≤T a1 ≤-1.5℃, -6℃≤T a2 ≤-4℃, -11℃≤T a3 ≤-9℃.

5. The defrosting method according to claim 4, characterized in that, Among the defrosting conditions corresponding to the multiple preset ambient temperature ranges, the conditions that the evaporation temperature needs to meet include that the evaporation temperature is less than or equal to the preset maximum evaporation temperature. Furthermore, the higher the ambient temperature of the preset ambient temperature range, the higher the maximum evaporation temperature in the conditions that the evaporation temperature needs to meet.

6. The defrosting method according to claim 4, characterized in that, In the defrosting conditions corresponding to the first ambient temperature range, the conditions that the evaporation temperature needs to meet include: the time for the evaporation temperature to drop by 1°C is within a preset time range; Among the defrosting conditions corresponding to the second, third, and fourth ambient temperature ranges, the evaporation temperature needs to meet the following conditions: the evaporation temperature must be less than or equal to the preset maximum evaporation temperature. Furthermore, the higher the preset ambient temperature range, the higher the maximum evaporation temperature must be among the conditions for the evaporation temperature to meet.

7. The defrosting method according to claim 5 or 6, characterized in that, The second ambient temperature range, the third ambient temperature range, and the fourth ambient temperature range each correspond to multiple defrosting conditions; Each defrosting condition corresponding to the second ambient temperature range, the third ambient temperature range, and the fourth ambient temperature range also includes the condition that the outlet water temperature needs to meet. In each defrosting condition corresponding to the second, third, and fourth ambient temperature ranges, the outlet water temperature must be within a preset outlet water temperature range, and the running time must be greater than or equal to a preset minimum running time; the preset outlet water temperature ranges in the multiple defrosting conditions corresponding to the second, third, and fourth ambient temperature ranges do not overlap. Any two defrosting conditions corresponding to the second ambient temperature range, the third ambient temperature range, and the fourth ambient temperature range shall satisfy the following: if the outlet water temperature in the outlet water temperature range of the first defrosting condition is higher than the outlet water temperature in the outlet water temperature range of the second defrosting condition, then the minimum running time in the first defrosting condition is greater than the minimum running time in the second defrosting condition.

8. The defrosting method according to claim 5, characterized in that, The first ambient temperature range corresponds to the defrosting condition: C 11 C 11 The minimum running time is t 11 The maximum evaporation temperature is T. e1 ,33min≤t 11 ≤37min, -12℃≤T e1 ≤-8℃.

9. The defrosting method according to claim 6, characterized in that, The first ambient temperature range corresponds to the defrosting condition: C 12 C 12 The minimum running time is t 11 33min≤t 11 ≤37min, the preset time range is: [50s, 10min].

10. The defrosting method according to claim 7, characterized in that, The second ambient temperature range corresponds to three defrosting conditions: C 21 C 22 and C 23 C 21 The outlet water temperature range is greater than or equal to T. wout21 The minimum running time is t for the interval. 21 The maximum evaporation temperature is T. e2 C 22 The outlet water temperature range is (T) wout22 ,T wout21 The minimum running time is t. 22 The maximum evaporation temperature is T. e2 C 23 The outlet water temperature range is less than or equal to T. wout22 The minimum running time is t for the interval. 23 The maximum evaporation temperature is T. e2 ; Among them, 30℃≤T wout21 ≤36℃, 22℃≤T wout22 ≤28℃, 38min≤t 21 ≤42min, 33min≤t 22 ≤37min, 28min≤t 23 ≤32min; -17℃≤T e2 ≤-13℃。 11. The defrosting method according to claim 7, characterized in that, The third ambient temperature range corresponds to three defrosting conditions: C 31 C 32 and C 33 C 31 The outlet water temperature range is greater than or equal to T. wout31 The minimum running time is t for the interval. 31 The maximum evaporation temperature is T. e3 C 32 The outlet water temperature range is (T) wout32 ,T wout31 The minimum running time is t. 32 The maximum evaporation temperature is T. e3 C 33 The outlet water temperature range is less than or equal to T. wout32 The minimum running time is t for the interval. 33 The maximum evaporation temperature is T. e3 ; Among them, 30℃≤T wout31 ≤36℃, 22℃≤T wout32 ≤28℃, 62min≤t 31 ≤68min, 52min≤t 32 ≤58min, 42min≤t 33 ≤48min; -22℃≤T e3 ≤-18℃。 12. The defrosting method according to claim 7, characterized in that, The fourth ambient temperature range corresponds to three defrosting conditions: C 41 C 42 and C 43 C 41 The outlet water temperature range is greater than or equal to T. wout41 The minimum running time is t for the interval. 41 The maximum evaporation temperature is T. e4 C 42 The outlet water temperature range is (T) wout42 ,T wout41 The minimum running time is t. 42 The maximum evaporation temperature is T. e4 C 43 The outlet water temperature range is less than or equal to T. wout42 The minimum running time is t for the interval. 43 The maximum evaporation temperature is T. e4 ; Among them, 30℃≤T wout41 ≤36℃, 22℃≤T wout42 ≤28℃, 130min≤t 41 ≤150min, 110min≤t 42 ≤130min, 90min≤t 43 ≤110min; -27℃≤T e4 ≤-23℃。 13. The defrosting method according to claim 1, characterized in that, The method further includes: During the defrosting operation of the evaporator, the air source heat pump unit's evaporator is periodically judged based on the recorded defrosting duration, received pressure data, and received outlet water temperature to determine whether the defrosting condition is met. Once it is determined that the evaporator meets the conditions for stopping defrosting, the defrosting operation is stopped.

14. The defrosting method according to claim 13, characterized in that, The periodic determination of whether the evaporator of the air source heat pump unit still meets the conditions for stopping defrosting, based on the recorded defrosting duration, received pressure data, and received outlet water temperature, includes: If any one of the following conditions is met, the evaporator is determined to meet the defrosting stop condition: The recorded defrosting time is greater than or equal to a preset defrosting time threshold; The received current outlet water temperature is less than the preset outlet water temperature threshold, and the duration is greater than or equal to the preset first time threshold. If the high-pressure side data during the defrosting operation is greater than or equal to a preset high-pressure threshold, and the high-pressure side data during the defrosting operation is continuously greater than or equal to the preset high-pressure threshold for a duration that reaches a preset second time threshold; If the high-pressure side data at the start of the defrosting operation is less than the preset high-pressure threshold, and the high-pressure side data during the defrosting operation is detected to be greater than or equal to the high-pressure side data at the start of the defrosting operation for a duration that reaches a preset third time threshold.

15. A defrosting method for an air source heat pump unit, the method comprising: Determine if the defrost temperature sensor installed in the air source heat pump unit is working properly; When the defrost temperature sensor is working normally, the evaporator of the air source heat pump unit is determined to meet the defrost conditions based on the temperature data from the defrost temperature sensor. After determining that the evaporator meets the defrost conditions based on the temperature data, the defrost operation is performed on the evaporator. If the defrost temperature sensor fails to function properly, the defrost method as described in any one of claims 1-14 shall be performed.

16. A non-transient computer-readable storage medium storing one or more program instructions that can be executed by one or more processors to implement the defrosting method for an air source heat pump unit as described in any one of claims 1-14 or as described in claim 15.

17. A defrosting device for an air source heat pump unit, characterized in that, The device includes: Memory is configured to store computer program instructions that can be executed on a processor; The processor is configured to execute the computer program instructions to implement the defrosting method for an air source heat pump unit as described in any one of claims 1-14 or as described in claim 15.

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