Self-adaptive defrosting control method of heat pump system and heat pump system

Abstract

The invention relates to a self-adaptive defrosting control method of a heat pump system and the heat pump system.The minimum defrosting interval time is determined by monitoring the outer side temperature TPG of an evaporator coil, the outer side relative humidity RHPG of the coil, the environment temperature TH and the environment relative humidity RH, and the minimum defrosting interval time is corrected by monitoring the rain and snow conditions of the place where the heat pump system is located; and defrosting control is carried out by adopting the corrected minimum defrosting interval time, and the optimal regular defrosting time can be adaptively set for the heat pump system according to the environment and the weather condition of the place where the heat pump system is located. The self-adaptively generated regular defrosting time is the corrected minimum defrosting interval time, so that the negative influence of a frost layer on the heat transfer performance of the evaporator can be effectively reduced, and stable operation of equipment is kept; electric energy consumption can be reduced and energy utilization rate can be increased; mechanical loss can be avoided, and the overall service life of the heat pump system is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pump control, and particularly to an adaptive defrost control method for a heat pump system and a heat pump system. Background Art

[0002] A heat pump system is an efficient and environmentally friendly energy utilization technology. Its core working principle is the reverse Carnot cycle. By consuming a small amount of electric energy or other energy, the heat energy in the low-temperature heat source is compressed by a compressor to become high-temperature heat energy, and then transmitted to the place where heating or cooling is required. It is highly favored by consumers and users and has been widely used for refrigeration and hot water supply in hotels, schools, hospitals, saunas, beauty salons, swimming pools, laundries and other places.

[0003] In a heat pump system, the defrost control of the evaporator has an important impact on the energy efficiency of the heat pump system, the user's heating and cooling comfort.

[0004] Traditional defrost control uses a fixed defrost interval time, or sets the parameters for judging the start of defrost to be fixed and the parameter indicators to be fixed values, and cannot perform reasonable and efficient defrost according to the actual operating conditions of the heat pump system and the weather conditions at the location of the heat pump system. Especially in China, the north-south latitude span is large. On the one hand, in the north, the winter temperature is low and the humidity is low, and the frosting speed is relatively slow; in the south, it is easy to frost in the range of -10°C to 10°C in winter, and the humidity in the south is high in winter, so it is easy to frost and the frosting speed is relatively fast; on the other hand, even in the north or south, the weather conditions in different cities are also different; if the defrost control parameters of the heat pump system remain fixed, there will be phenomena of not defrosting when there is frost, incomplete defrosting or frequent defrosting in different regions and different cities, resulting in too much heat consumption of the heat pump system, the energy efficiency of the heat pump system becoming low, affecting the user experience and the product reputation. And in winter, when the heat pump system switches the refrigerant flow path to control the defrost of the evaporator, for the condenser, it enters the refrigeration mode, seriously affecting the user's heating experience. However, winter defrost is necessary, and how to make the heat pump system perform reasonable and efficient defrost is particularly important. Summary of the Invention

[0005] Based on this, the purpose of the present invention is to provide an adaptive defrost control method for a heat pump system to solve the problems of not defrosting when there is frost, incomplete defrosting or frequent defrosting caused by the fixed defrost interval time set by the program of the heat pump system, which cannot adapt to the environment where the heat pump system is located, resulting in the low energy efficiency of the heat pump system and affecting the user experience.

[0006] An adaptive defrost control method for a heat pump system includes:

[0007] S10 Obtain the temperature T outside the coil of the evaporator of the heat pump system PGand the relative humidity RH outside the coil PG , and obtain the dew point temperature T outside the coil accordingly DP ; Determine whether the temperature T outside the coil PG is less than or equal to 0°C and less than or equal to the dew point temperature T DP :

[0008] If yes, execute S20;

[0009] If no, continuously obtain the temperature T outside the coil PG and the relative humidity RH outside the coil PG ;

[0010] S20 Obtain the ambient temperature T H , the ambient relative humidity RH, and accordingly determine the frosting area where the heat pump system is located, and obtain the corresponding minimum defrosting interval time based on the frosting area;

[0011] S30 Obtain the rain and snow conditions at the location of the heat pump system, correct the minimum defrosting interval time t according to the rain and snow conditions to obtain the corrected minimum defrosting interval time t′, and control the four-way valve to perform reversing defrosting according to the corrected minimum defrosting interval time.

[0012] Furthermore, the corrected minimum defrosting interval time t′ satisfies:

[0013] t′ = α * t

[0014] where t is the minimum defrosting interval time. When the rain and snow condition is no snow or no freezing rain, the correction coefficient α is 1.0; when the rain and snow condition is light snow, the correction coefficient α is 0.9; when the rain and snow condition is moderate snow or heavy snow, the correction coefficient α is 0.85; when the rain and snow condition is freezing rain, the correction coefficient α is 0.8.

[0015] Furthermore, data interaction with the cloud platform is carried out through the 4G / 5G / WIFI module every 0.5 hours to 1.0 hours, and the rain and snow conditions at the location of the heat pump system are obtained through the cloud platform.

[0016] Furthermore, the step S20 includes the following sub-steps:

[0017] S21 Obtain the ambient temperature T H :

[0018] If the ambient temperature T H is within the low temperature range [T limt-down , T limt-up , then execute S22;

[0019] If the ambient temperature T H is lower than the lower limit value T limt-down of the low temperature range, or higher than the upper limit value T limt-up, then execute S23;

[0020] S22 obtains the environmental relative humidity RH:

[0021] If the environmental relative humidity RH is within the high humidity range [RH H-down , RH H-up , then it is determined that the heat pump system is in the heavy frost area, and the minimum defrosting interval time is t1;

[0022] If the environmental relative humidity RH is within the medium humidity range [RH M-down , RH H-down )], then it is determined that the heat pump system is in the strong frost area, and the minimum defrosting interval time is t2;

[0023] If the environmental relative humidity RH is within the low humidity range [RH L-down , RH M-down )], then it is determined that the heat pump system is in the medium-strong frost area, and the minimum defrosting interval time is t3;

[0024] S23 obtains the environmental relative humidity RH:

[0025] If the environmental relative humidity RH is within the high humidity range [RH H-down , RH H-up , then it is determined that the heat pump system is in the medium frost area, and the minimum defrosting interval time is t4;

[0026] If the environmental relative humidity RH is within the medium humidity range [RH M-down , RH H-down )], then it is determined that the heat pump system is in the medium-weak frost area, and the minimum defrosting interval time is t5;

[0027] If the environmental relative humidity RH is within the low humidity range [RH L-down , RH M-down )], then it is determined that the heat pump system is in the weak frost area, and the minimum defrosting interval time is t6;

[0028] Among them, t1 < t2 < t3 < t4 < t5 < t6.

[0029] Furthermore, the low temperature range is [T limt-down , T limt-up is [-5°C, 5°C].

[0030] Furthermore, the high humidity range [RH H-down , RH H-up is [80%, 100%]; the medium humidity range [RH M-down , RH H-down ) is [65%, 80%); the low humidity range [RH L-down , RH M-down ) is [the theoretical lower limit of RH, 65%).

[0031] Further, t1 is set to 25°C ± 1°C; t2 is set to 30°C ± 1°C; t3 is set to 40°C ± 1°C, t4 is set to 60°C ± 2°C; t5 is set to 90°C ± 2°C; t6 is set to 180°C ± 2°C.

[0032] Further, a multi-variable linear regression formula is used to calculate the dew point temperature T DP , a large number of meteorological observation data at the location of the heat pump system need to be collected, a linear regression relationship between the dew point temperature and temperature, relative humidity is established, the regression coefficients are fitted, then T DP satisfies:

[0033] T DP = α×T + β×RH + C:

[0034] In the formula: α, β, C are the fitted regression coefficients, T is the actual temperature at the location of the heat pump system, and RH is the relative humidity at the location of the heat pump system.

[0035] Further, the Magnus-Tetens formula is used to calculate the dew point temperature T DP , a large number of meteorological observation data at the location of the heat pump system need to be collected, a relationship between the dew point temperature and temperature, relative humidity is established, the correction constant is fitted, then T DP satisfies:

[0036]

[0037] In the formula, a, b are the correction constants, T is the actual temperature at the location of the heat pump system, and RH is the relative humidity at the location of the heat pump system.

[0038] Compared with the prior art, the present invention determines the minimum defrost interval time by monitoring the temperature T PG outside the evaporator coil, the relative humidity RH PG outside the coil, the ambient temperature T H and the ambient relative humidity RH, corrects the minimum defrost interval time by monitoring the rain and snow conditions at the location of the heat pump system, and uses the corrected minimum defrost interval time for defrost control, which can adaptively set the most suitable regular defrost time for the heat pump system according to the environment and the local weather conditions. The adaptively generated regular defrost time, i.e., the corrected minimum defrost interval time, can effectively reduce the negative impact of the frost layer on the heat transfer performance of the evaporator, keep the equipment running stably; can reduce power consumption and improve energy utilization efficiency; can avoid mechanical wear and tear and extend the overall service life of the heat pump system.

[0039] Meanwhile, the present invention also provides a heat pump system with adaptive defrost control.

[0040] A heat pump system with adaptive defrost control includes a compressor, a four-way valve, a condenser, an electronic expansion valve, an evaporator connected in sequence through a refrigerant circulation pipeline, a temperature and humidity monitoring module, and a main controller electrically connected and / or communicatively connected to the four-way valve and the temperature and humidity monitoring module. The main controller includes a 4G / 5G / WiFi module. The 4G / 5G / WiFi module obtains the rain and snow conditions at the location of the heat pump system through a cloud platform. The main controller controls the four-way valve to reverse for defrosting through the above-mentioned adaptive defrost control method.

[0041] The beneficial effects of the heat pump system with adaptive defrost control proposed by the present invention are the same as those of the above-mentioned adaptive defrost control method and will not be elaborated here.

[0042] For better understanding and implementation, the present invention will be described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic structural diagram of a heat pump system according to an embodiment of the present invention;

[0044] Figure 2 It is a schematic diagram of data interaction of a 4G module according to an embodiment of the present invention;

[0045] Figure 3 It is a flowchart of an adaptive defrost control method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0047] To solve the problem that in the defrost control of existing heat pump systems, due to the fixed defrost interval time set by the program and the fixed parameter values for defrost condition judgment, the heat pump system cannot adapt to the weather conditions at the location of the heat pump system, resulting in non-removal of frost, incomplete defrosting, or frequent defrosting, which reduces the capacity and energy efficiency of the heat pump system and affects the user experience. The present invention proposes an adaptive defrost control method for a heat pump system. This method obtains real-time weather data of the heat pump system, determines the monitoring parameters for starting defrost according to the weather conditions, and controls the heat pump system to perform defrost control according to the determined monitoring parameters. Compared with the traditional heat pump system that sets temperature and humidity sensors, starts defrost according to the relationship between the ambient temperature, humidity and the set threshold, and sets a fixed defrost method, this control method can adapt to the weather conditions at the location of the heat pump system, achieve reasonable and efficient defrosting with frost removal when there is frost and no random defrosting when there is no frost, improve the capacity and energy efficiency of the heat pump system, and bring a better heating experience for users.

[0048] At the same time, based on an adaptive defrost control method for a heat pump system, the present invention proposes a heat pump system with adaptive defrost control.

[0049] For specific implementation, please refer to Figure 1 The heat pump system with adaptive defrost control proposed by the present invention includes a compressor 10, a four-way valve 20, a condenser 30, an electronic expansion valve 40, an evaporator 50, a temperature and humidity monitoring module (not shown in the figure), a main controller (not shown in the figure), and other auxiliary pipe fittings, which are connected in a cycle through a refrigerant pipeline. The main controller is electrically connected and / or communicatively connected to the four-way valve 20 and the temperature and humidity monitoring module.

[0050] Please refer to Figure 2 The main controller includes a 4G / 5G / WiFi module. The 4G / 5G / WiFi module obtains the weather conditions at the location of the heat pump system through the cloud platform and transmits the weather conditions to the main controller. The main controller controls the defrosting of the heat pump unit according to the obtained weather conditions and the temperature and humidity parameters monitored by the temperature and humidity monitoring module. Specifically, the 4G / 5G / WiFi module performs data interaction with the cloud platform at a set time interval to obtain the weather data at the location of the heat pump system; and the cloud platform also performs data interaction with the weather monitoring station at the location of the heat pump system at a set time interval. The weather monitoring station at the location of the heat pump system transmits the real-time monitored weather data to the cloud platform. In this embodiment, it is set that the cloud platform performs data interaction with the weather monitoring station at the location of the heat pump system every 0.5 hours to 1.0 hours; the 4G / 5G / WiFi module performs data interaction with the cloud platform every 0.5 hours to 1.0 hours.

[0051] The temperature and humidity monitoring module includes a first temperature and humidity sensor and a second temperature and humidity sensor. The first temperature and humidity sensor is arranged outside the coil of the evaporator 50 and is used to collect the temperature T PG outside the coil of the evaporator 50 and the relative humidity RH PG . The second temperature and humidity sensor is arranged at any position in the heat pump system where the ambient temperature and humidity can be monitored and is used to collect the ambient temperature T H and the ambient relative humidity RH.

[0052] A method for adaptive defrost control of a heat pump system is stored on the main controller. The main controller controls the four-way valve to change the direction for defrosting through this control method. This control method includes the following steps:

[0053] S10 Obtain the temperature T PG outside the coil of the evaporator 50 and the relative humidity RH PG outside the coil of the evaporator 50, and obtain the dew point temperature T DP outside the coil of the evaporator 50 accordingly; judge whether the temperature T PG outside the coil of the evaporator 50 is less than or equal to 0 °C and less than or equal to the dew point temperature T DP outside the coil of the evaporator 50:

[0054] If it is, then execute S20;

[0055] If not, continuously obtain the temperature T outside the coil PG and the relative humidity RH outside the coil PG .

[0056] In specific implementation, based on the temperature T outside the coil PG and the relative humidity RH outside the coil PG obtain the dew point temperature T outside the coil DP . It can be calculated using a multivariable linear regression formula, or using the Magnus-Tetens formula, or by looking up in a dew point temperature table. This application does not make any restrictions

[0057] If calculated using a multivariable linear regression formula, a large amount of meteorological observation data at the location of the heat pump system needs to be collected, establish a linear regression relationship between the dew point temperature and temperature, relative humidity, and fit the regression coefficients. Then T DP satisfies

[0058] T DP = α×T + β×RH + C

[0059] In the formula: α, β, C are the fitted regression coefficients, T is the actual temperature at the location of the heat pump system, and RH is the relative humidity at the location of the heat pump system

[0060] If calculated using the Magnus-Tetens formula, a large amount of meteorological observation data at the location of the heat pump system needs to be collected, establish a relationship between the dew point temperature and temperature, relative humidity, and fit the correction constant. Then T DP satisfies

[0061]

[0062] In the formula, a, b are the correction constants, T is the actual temperature at the location of the heat pump system, and RH is the relative humidity at the location of the heat pump system

[0063] If looking up in a dew point temperature table, a dew point temperature table published by the meteorological department or relevant institution at the location of the heat pump system needs to be collected

[0064] The surface temperature of the evaporator needs to simultaneously satisfy being lower than the dew point temperature of the air on the surface of the evaporator and lower than 0°C to cause the water vapor in the air on the air side surface to condense and freeze into frost

[0065] S20 Obtain the ambient temperature T H and the ambient relative humidity RH, and based on this, determine the frosting area where the heat pump system is located, and obtain the corresponding minimum defrost interval time based on the frosting area

[0066] In specific implementation, it includes the following sub-steps

[0067] S21 Obtain the ambient temperature T H :

[0068] If the ambient temperature T H is within the low temperature range [T limt-down , T limt-up , then execute S22;

[0069] If the ambient temperature T H is lower than the lower limit value T limt-down of the low temperature range, or higher than the upper limit value T limt-up of the low temperature range, then execute S23.

[0070] The low temperature range is the temperature range where frosting is more likely to occur. In this embodiment, the low temperature range is [T limt-down , T limt-up which is [-5°C, 5°C], where the lower limit value T limt-down of the low temperature range is -5°C, and the upper limit value T limt-up of the low temperature range is 5°C. The lower limit value T limt-down and the upper limit value T limt-up of the low temperature range can also be corrected according to the meteorological observation data at the location of the heat pump system.

[0071] S22 Obtain the ambient relative humidity RH:

[0072] If the ambient relative humidity RH is within the high humidity range [RH H-down , RH H-up , then it is determined that the heat pump system is in the heavy frosting area, and the minimum defrosting interval time is t1;

[0073] If the ambient relative humidity RH is within the medium humidity range [RH M-down , RH H-down )], then it is determined that the heat pump system is in the strong frosting area, and the minimum defrosting interval time is t2;

[0074] If the ambient relative humidity RH is within the low humidity range [RH L-down , RH M-down )], then it is determined that the heat pump system is in the medium-strong frosting area, and the minimum defrosting interval time is t3.

[0075] Where t1 < t2 < t3. In this embodiment, t1 is set to 25°C ± 1°C; t2 is set to 30°C ± 1°C; t3 is set to 40°C ± 1°C.

[0076] The high humidity range [RH H-down , RH H-up is [80%, 100%]; the medium humidity range [RH M-down , RH H-down ) is [65%, 80%); the low humidity range [RH L-down , RHM-down ) is [lower limit of RH theory, 65%). The lower limit value of RH in the high humidity range [RH H-down , RH H-up can also be corrected according to the meteorological observation data at the location of the heat pump system. For the lower limit value of RH in the medium humidity range [RH H-down , RH M-down , RH H-down ) is corrected. M-down

[0077] S23 Obtain the environmental relative humidity RH:

[0078] If the environmental relative humidity RH is within the high humidity range [RH H-down , RH H-up , it is determined that the heat pump system is in the medium frost area, and the minimum defrosting interval time is t4;

[0079] If the environmental relative humidity RH is within the medium humidity range [RH M-down , RH H-down ), it is determined that the heat pump system is in the medium-weak frost area, and the minimum defrosting interval time is t5;

[0080] If the environmental relative humidity RH is within the low humidity range [RH L-down , RH M-down ), it is determined that the heat pump system is in the weak frost area, and the minimum defrosting interval time is t6.

[0081] Among them, t4 < t5 < t6. In this embodiment, t4 is set to 60°C ± 2°C; t5 is set to 90°C ± 2°C; t6 is set to 180°C ± 2°C.

[0082] The settings of the high humidity range [RH H-down , RH H-up , the medium humidity range [RH M-down , RH H-down ), and the low humidity range [RH L-down , RH M-down ) are the same as those in S22.

[0083] In summary, t1 < t2 < t3 < t4 < t5 < t6.

[0084] The influence of environmental temperature and humidity on frosting: In the low temperature range, combined with the high humidity range, the frosting phenomenon is the most significant, and the greater the humidity, the thicker the frost layer; below the lower limit of the low temperature range, the absolute moisture content of the air decreases, and the frosting probability decreases. However, if the relative humidity is still at a relatively high level, there is still a chance of frosting; above the upper limit of the low temperature range, as the temperature rises, the saturated absolute moisture content (the maximum water vapor capacity) in the air increases. At this time, even if the relative humidity decreases, due to the large base of the saturated moisture content at high temperatures, the absolute moisture content corresponding to the low relative humidity may still meet the frosting conditions.

[0085] S30 obtains the rain and snow conditions at the location of the heat pump system, corrects the minimum defrost interval time t according to the rain and snow conditions to obtain the corrected minimum defrost interval time t′, and controls the four-way valve to perform reverse defrosting according to the corrected minimum defrost interval time.

[0086] In specific implementation, the 4G / 5G / WiFi module interacts with the cloud platform every 0.5 hours to 1.0 hours, and obtains the weather conditions at the location of the heat pump system through the cloud platform.

[0087] The rain and snow conditions include no snow, no freezing rain, light snow, moderate snow, heavy snow and freezing rain.

[0088] The corrected minimum defrost interval time t′ satisfies:

[0089] t′ = α * t

[0090] Wherein, for no snow or no freezing rain, the correction coefficient α is 1.0; for light snow, the correction coefficient α is 0.9; for moderate snow or heavy snow, the correction coefficient α is 0.85; for freezing rain, the correction coefficient α is 0.8.

[0091] According to the above method, the following example is provided to show the calculation of the corrected minimum defrost interval time, as shown in Table 1.

[0092] Table 1

[0093]

[0094]

[0095] The present invention determines the minimum defrost interval time by monitoring the temperature T outside the evaporator coil PG , the relative humidity RH outside the coil PG , the ambient temperature T H , and the ambient relative humidity RH, corrects the minimum defrost interval time by monitoring the rain and snow conditions at the location of the heat pump system, and uses the corrected minimum defrost interval time for defrost control, which can adaptively set the most suitable regular defrost time for the heat pump system according to the environment and the local weather conditions. The adaptively generated regular defrost time, that is, the corrected minimum defrost interval time, can prevent the evaporator from being hindered by too thick frost layer for heat transfer, resulting in temperature fluctuations inside the heat pump system, and can effectively reduce the negative impact of the frost layer on the heat transfer performance of the evaporator and keep the equipment running stably; it can avoid that too thick frost layer increases the working load of the compressor or the motor and significantly increases the power consumption, and can reduce the power consumption and improve the energy utilization rate; it can avoid the aging or damage of the evaporator caused by long-term frosting due to overloading, and can avoid mechanical wear and extend the overall service life of the heat pump system.

[0096] In specific implementation, the main controller is an electronic device, which includes, but is not limited to, a memory, a processor, a network interface, and a 4G / 5G / WiFi module that can communicate with each other through a system bus.

[0097] Among them, the electronic device can be a computing device such as a rack server, a blade server, a tower server, or a cabinet server.

[0098] The memory includes at least one type of readable storage medium, and the readable storage medium includes flash memory, hard disk, multimedia card, card-type memory (such as SD or DX memory, etc.), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, magnetic disk, optical disk, etc. The memory can be an internal storage unit of the electronic device, such as the hard disk or memory of the electronic device. The memory can also be an external storage device of the electronic device, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. equipped on the electronic device. The memory can also include both the internal storage unit and the external storage device of the electronic device.

[0099] The processor can be a Central Processing Unit (CPU), a microcontroller, a microprocessor, or other data processing chips. The processor is usually used to control the overall operation of the electronic device, such as performing control and processing related to data interaction or communication with the electronic device. The processor is used to run the program code stored in the memory or process data, such as running the adaptive defrost control method, etc.

[0100] The network interface can include a wireless network interface or a wired network interface, and this network interface is usually used to establish a communication connection between the electronic device and other electronic devices. For example, the network interface is used to connect the electronic device to an external data platform through a network, and establish a data transmission channel and a communication connection between the electronic device and the external data platform. The network can be a wireless or wired network such as an enterprise internal network (Intranet), the Internet, Global System of Mobile communication (GSM), Wideband Code Division Multiple Access (WCDMA), 4G network, 5G network, Bluetooth, Wi-Fi, etc.

[0101] The 4G / 5G / WiFi module establishes a communication connection with the cloud platform through a network interface.

[0102] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present application. The singular forms "a", "the", and "said" used in the embodiments of the present application and the claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that unless otherwise stated, "a plurality" and "several" refer to two or more; "and / or" means any or all possible combinations including one or more of the associated listed items; "first", "second", "third", etc. are only used for distinction and not for describing a specific order or sequence, nor can they be understood as indicating or implying relative importance. When the above description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of the present application, for those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0103] The above embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and the present invention also intends to include these changes and modifications.

Claims

1. An adaptive defrosting control method for a heat pump system, characterized in that, Including: S10 Obtain the temperature T on the outer side of the coil of the heat pump system evaporator PG and the relative humidity RH on the outer side of the coil PG , and obtain the dew point temperature T on the outer side of the coil based on this DP ; Determine whether the temperature T on the outer side of the coil PG is less than or equal to 0 °C and less than or equal to the dew point temperature T DP : If it is yes, then execute S20; If the answer is no, continuously obtain the temperature T outside the coil PG and the relative humidity RH outside the coil PG ; S20 Obtain the ambient temperature T H , the ambient relative humidity RH, and based on this, determine the frosting area where the heat pump system is located, and obtain the corresponding minimum defrosting interval time based on the frosting area; S30 obtains the rain and snow conditions at the location of the heat pump system, corrects the minimum defrost interval time t according to the rain and snow conditions to obtain the corrected minimum defrost interval time t′, and controls the four-way valve to perform reversing defrosting according to the corrected minimum defrost interval time.

2. The adaptive defrosting control method according to claim 1, wherein The corrected minimum defrost interval time t′ satisfies: t′ = α * t Wherein, t is the minimum defrost interval time. When the rain and snow condition is no snow or no freezing rain, the correction coefficient α is 1.0; when the rain and snow condition is light snow, the correction coefficient α is 0.9; when the rain and snow condition is moderate snow or heavy snow, the correction coefficient α is 0.85; when the rain and snow condition is freezing rain, the correction coefficient α is 0.

8.

3. The adaptive defrosting control method according to claim 2, wherein Data interaction with the cloud platform is carried out through the 4G / 5G / WIFI module every 0.5 hours to 1.0 hours, and the rain and snow conditions at the location of the heat pump system are obtained through the cloud platform.

4. The adaptive defrosting control method according to claim 2, wherein The step S20 includes the following sub-steps: S21 Obtain the ambient temperature T H : If the ambient temperature T H is in the low temperature range [T limt-down , T limt-up , then execute S22; If the ambient temperature T H is lower than the lower limit value T limt-down of the low temperature range, or higher than the upper limit value T limt-up of the low temperature range, then execute S23; S22 obtains the ambient relative humidity RH: If the environmental relative humidity RH is in the high humidity range [RH H-down , RH H-up , it is determined that the heat pump system is in the heavy frost area, and the minimum defrosting interval time is t1; If the environmental relative humidity RH is in the medium humidity range [RH M-down , RH H-down ), it is determined that the heat pump system is in the strong frosting area, and the minimum defrosting interval time is t2; If the environmental relative humidity RH is in the low humidity range [RH L-down , RH M-down ), it is determined that the heat pump system is in the medium and strong frosting area, and the minimum defrosting interval time is t3; S23 obtains the ambient relative humidity RH: If the environmental relative humidity RH is in the high humidity range [RH H-down , RH H-up , it is determined that the heat pump system is in the medium frosting area, and the minimum defrosting interval time is t4; If the environmental relative humidity RH is within the medium humidity range [RH M-down , RH H-down ), it is determined that the heat pump system is in the medium weak frosting area, and the minimum defrosting interval time is t5; If the environmental relative humidity RH is in the low humidity range [RH L-down , RH M-down ), it is determined that the heat pump system is in the weak frosting area, and the minimum defrosting interval time is t6; Wherein, t1 < t2 < t3 < t4 < t5 < t6.

5. The adaptive defrosting control method according to claim 4, wherein The low temperature range is [T limt-down , T limt-up and is [-5°C, 5°C].

6. The adaptive defrosting control method according to claim 5, wherein, High humidity range [RH H-down , RH H-up is [80%, 100%]; Medium humidity range [RH M-down , RH H-down ) is [65%, 80%); Low humidity range [RH L-down , RH M-down ) is [Lower theoretical limit of RH, 65%).

7. The adaptive defrosting control method according to claim 6, wherein t1 is set to 25°C ± 1°C; t2 is set to 30°C ± 1°C; t3 is set to 40°C ± 1°C, t4 is set to 60°C ± 2°C; t5 is set to 90°C ± 2°C; t6 is set to 180°C ± 2°C.

8. The adaptive defrosting control method according to claim 1, characterized in that Calculate the dew point temperature T using a multi-variable linear regression formula DP , a large amount of meteorological observation data at the location of the heat pump system needs to be collected, establish a linear regression relationship between the dew point temperature, temperature, and relative humidity, fit the regression coefficients, then T DP Satisfies: T DP = α × T + β × RH + C: In the formula: α, β, C are the fitted regression coefficients, T is the actual temperature at the location of the heat pump system, and RH is the relative humidity at the location of the heat pump system.

9. The adaptive defrosting control method according to claim 1, characterized in that, The Magnus-Tetens formula is used to calculate the dew point temperature T DP , a large number of meteorological observation data at the location of the heat pump system need to be collected, the relationship between the dew point temperature, temperature, and relative humidity is established, and the correction constant is fitted, then T DP Satisfies: In the formula, a, b are correction constants, T is the actual temperature at the location of the heat pump system, and RH is the relative humidity at the location of the heat pump system.

10. A heat pump system with adaptive defrosting control, comprising a compressor, a four-way valve, a condenser, an electronic expansion valve, an evaporator connected in sequence through a refrigerant circulation pipeline, a temperature and humidity monitoring module, and a main controller electrically connected and / or communicatively connected to the four-way valve and the temperature and humidity monitoring module, characterized in that, The main controller includes a 4G / 5G / WIFI module. The 4G / 5G / WIFI module obtains the rain and snow conditions at the location of the heat pump system through the cloud platform, and the main controller controls the four-way valve to perform reversing defrosting by the adaptive defrost control method described in claims 1 to 9.

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