Heat pump air conditioner control method, device and system and air conditioner

Abstract

The invention discloses a heat pump air conditioner control method, device and system and an air conditioner. Belongs to the air-conditioning control field. The control method comprises the steps that after defrosting of the heat pump air conditioner is finished, the outdoor environment temperature is obtained, when the outdoor environment temperature is smaller than a first preset outdoor environment temperature, a compressor frequency compensation control mode is started from a normal control mode, and in the compressor frequency compensation control mode, a compressor frequency compensation control mode is started from a compressor frequency compensation control mode; and the second frequency slow-rising current is compensated to obtain the first frequency slow-rising current, so that when the target current is larger than the second frequency slow-rising current, frequency slow-rising control cannot be performed on the compressor, and the frequency rising space of the compressor is increased. And when the target current reaches the second current threshold value in the normal control mode, frequency limiting or frequency reduction control is not directly carried out, and it can be guaranteed that when the heat pump air conditioner operates in a heating mode under the low-temperature working condition, the heating capacity and reliability after defrosting are improved, and the comfort of a user is improved.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioning control, and in particular, to a heat pump air conditioner control method, device, system and air conditioner. Background Art

[0002] Traditional heat pump air conditioners have the problem of frosting when operating in low-temperature heating conditions. In order to increase the low-temperature heating capacity, there are currently several ways to achieve this.

[0003] 1) Shorten the defrost time as much as possible while still ensuring that the defrost is clean.

[0004] 2) Reduce the number of defrost cycles.

[0005] 3) After defrosting, quickly resume heating operation.

[0006] 4) Heating and defrosting can be achieved without reversing the four-way valve, such as the quick-melting technology for thin frost.

[0007] The solution of using four-way valve reversing to realize defrosting of outdoor units generally has the following problems:

[0008] 1) During the defrost process, the four-way valve switches to the indoor side and becomes cooling without heating. In the cooling state, although the indoor fan is in shutdown or low wind operation, the indoor ambient temperature and indoor coil temperature will still drop rapidly, resulting in poor thermal comfort.

[0009] 2) After a period of time after defrosting, the defrosting method achieved by reversing will cause the internal pipe temperature to drop very low. To prevent cold wind from blowing on people, the internal fan needs to wait until the indoor coil temperature rises to a certain value before starting. At this time, there is still no heating capacity on the indoor side, and the thermal comfort is poor.

[0010] 3) During the cold wind protection period after defrosting, the compressor frequency increases and the outdoor unit load is heavy. The total current and phase current increase rapidly, which can easily trigger the compressor frequency protection slow rise and frequency limit. Once the protection slow rise and frequency limit are triggered, the indoor unit pipe temperature rise will slow down, further prolonging the cold wind protection period and affecting the low-temperature heating capacity. Summary of the Invention

[0011] In order to overcome the deficiencies of the prior art, the present application provides a heat pump air conditioner control method, device, system and air conditioner to solve various problems existing after defrosting of the existing heat pump air conditioner.

[0012] The technical solution adopted by this application to solve its technical problems is:

[0013] In a first aspect, a method for controlling a heat pump air conditioner is provided, wherein the heat pump air conditioner uses a four-way valve for defrosting, the method comprising:

[0014] When the heat pump air conditioner completes defrosting and operates in a heating mode, obtaining the outdoor ambient temperature;

[0015] When the outdoor ambient temperature is lower than a first preset outdoor ambient temperature, the normal control mode enters the compressor frequency compensation control mode;

[0016] In the compressor frequency compensation control mode, if the target current is greater than the corresponding first frequency ramp-up current, the compressor is subjected to frequency ramp-up control, wherein the first frequency ramp-up current is greater than the second frequency ramp-up current, wherein the second frequency ramp-up current is the frequency ramp-up current in the normal control mode.

[0017] As an optional implementation of the present application, when the outdoor ambient temperature is lower than a first preset outdoor ambient temperature, entering the compressor frequency compensation control mode from the normal control mode includes:

[0018] When the outdoor ambient temperature is lower than the first preset outdoor ambient temperature and greater than or equal to the second preset outdoor ambient temperature, the normal control mode enters the first compressor frequency compensation control mode;

[0019] When the outdoor ambient temperature is lower than the second preset outdoor ambient temperature, the normal control mode enters the second compressor frequency compensation control mode;

[0020] Compared with the first compressor frequency compensation control mode, the second compressor frequency compensation control mode does not perform frequency limiting control and frequency reduction control on the compressor frequency.

[0021] As an optional implementation of this application, the following is also included:

[0022] In the first compressor frequency compensation control mode, a compensation threshold is determined based on the indoor pipe temperature, wherein the higher the indoor pipe temperature is, the smaller the compensation threshold is;

[0023] The second current threshold of the target current is compensated based on the compensation threshold to obtain the first current threshold of the same target current, wherein the second current threshold is any one of the frequency ramp-up current, frequency limiting current, and frequency reduction current of the target current in the normal control mode, and the first current threshold is any one of the frequency ramp-up current, frequency limiting current, and frequency reduction current of the same target current in the compressor frequency compensation control mode. For the same target current, the frequency reduction current > the frequency limiting current > the frequency ramp-up current.

[0024] As an optional implementation of the present application, the target current is one of the whole machine current and the compressor phase current;

[0025] The compensation threshold corresponding to the whole machine current is less than or equal to the compensation threshold corresponding to the compressor phase current.

[0026] As an optional implementation of this application, the following is also included:

[0027] When the indoor pipe temperature reaches the cold wind prevention exit set pipe temperature threshold, the internal fan is controlled to start, and the first compressor frequency compensation control mode is exited after a preset delay.

[0028] As an optional implementation of this application, the following is also included:

[0029] In the first compressor frequency compensation control mode, the first frequency ramp-up current of the target current is a difference between a shutdown current of the same target current and a preset correction value.

[0030] As an optional implementation of this application, the following is also included:

[0031] When the difference between the target frequency and the compressor frequency is less than or equal to the preset difference, if the compressor performs slow frequency increase control, the indoor fan is controlled based on the indoor pipe temperature;

[0032] The control of the indoor fan based on the indoor pipe temperature includes:

[0033] When the indoor pipe temperature is lower than a first preset indoor pipe temperature, the indoor fan is controlled to be prohibited from running;

[0034] When the indoor pipe temperature is greater than or equal to the first preset indoor pipe temperature and less than or equal to the second preset indoor pipe temperature, controlling the indoor fan to operate at a preset speed;

[0035] When the indoor pipe temperature is greater than the second preset indoor pipe temperature, the indoor fan is controlled based on actual demand.

[0036] As an optional implementation of this application, the following is also included:

[0037] After defrosting is completed, the compressor stops running and the electronic expansion valve is controlled to open to the maximum;

[0038] After the compressor stops for a specified period of time, the four-way valve is controlled to reverse, and the compressor is controlled to start running, and the operating frequency is recorded at the same time;

[0039] Start timing when the operating frequency reaches a preset operating frequency;

[0040] When the timing duration is equal to the preset duration, the opening degree of the electronic expansion valve is adjusted according to actual demand conditions.

[0041] In a second aspect, a heat pump air conditioner control device is provided, wherein the heat pump air conditioner uses a four-way valve for defrosting, and the device comprises:

[0042] An outdoor ambient temperature acquisition module, configured to acquire the outdoor ambient temperature when the heat pump air conditioner completes defrosting and operates in a heating mode;

[0043] a compensation control mode entry module, configured to enter the compressor frequency compensation control mode from the normal control mode when the outdoor ambient temperature is lower than a first preset outdoor ambient temperature;

[0044] In the compressor frequency compensation control mode, if the target current is greater than the corresponding first frequency ramp-up current, the compressor is subjected to frequency ramp-up control, wherein the first frequency ramp-up current is greater than the second frequency ramp-up current, wherein the second frequency ramp-up current is the frequency ramp-up current in the normal control mode.

[0045] In a third aspect, a heat pump air conditioner control system is provided, comprising:

[0046] at least one processor and at least one memory;

[0047] The memory stores executable instructions of the processor;

[0048] The processor is configured to execute any one of the above-mentioned heat pump air conditioner control methods.

[0049] In a fourth aspect, a heat pump air conditioner is provided, wherein the heat pump air conditioner applies any of the heat pump air conditioner control methods described above.

[0050] Beneficial effects:

[0051] The technical solution of the present application provides a heat pump air conditioner control method, device, system and air conditioner. Among them, the heat pump air conditioner adopts four-way valve reversing for defrosting, and the control method includes: after the heat pump air conditioner is defrosted, the outdoor ambient temperature is obtained, and when the outdoor ambient temperature is lower than the first preset outdoor ambient temperature, the normal control mode enters the compressor frequency compensation control mode, and in the compressor frequency compensation control mode, the second frequency ramp-up current is compensated to obtain the first frequency ramp-up current, so that when the target current is greater than the second frequency ramp-up current, the compressor will not be subjected to frequency ramp-up control, thereby increasing the frequency increase space of the compressor. Moreover, when the target current reaches the second current threshold value under the normal control mode, the frequency limiting or frequency reduction control will not be directly performed, which can ensure that when the heat pump air conditioner is operating in low-temperature conditions for heating, the heating capacity and reliability after defrosting are improved, thereby improving user comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0053] Figure 1 This is a flow chart of a heat pump air conditioner control method provided by an embodiment of the present application;

[0054] Figure 2 This is a control block diagram of a heat pump air conditioner control method provided by an embodiment of the present application;

[0055] Figure 3 This is a control logic block diagram of a heat pump air conditioner compressor frequency compensation control mode provided by an embodiment of the present application;

[0056] Figure 4 The embodiment of the present application provides an electronic expansion valve control for preventing oil blockage in a heat pump air conditioner after defrosting.

[0057] Figure 5 This is a schematic structural diagram of a heat pump air conditioner control device provided in an embodiment of the present application;

[0058] Figure 6 This is a schematic diagram of the structure of a heat pump air conditioner control system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0059] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application are described in detail below with reference to the accompanying drawings and examples. Obviously, the described embodiments are only some of the embodiments of this application, rather than all of them. Based on the embodiments in this application, all other implementation methods obtained by ordinary technicians in this field without making any creative work are within the scope of protection of this application.

[0060] It should be noted that the four-way valve reversing defrost mentioned in this application refers to adjusting the flow direction of the refrigerant through the four-way valve, adjusting the refrigerant flow direction from the heating mode to the cooling mode, and removing the frost on the heat exchanger through the refrigerant with a higher temperature.

[0061] In addition, it also includes setting up heat exchanger defrost or hot gas bypass defrost.

[0062] In addition, frequency ramp-up control means that when the whole machine current exceeds the corresponding frequency ramp-up current or the compressor phase current exceeds the corresponding frequency ramp-up current, the frequency of the compressor is slowed down. For example, before the frequency ramp-up control, the frequency per unit time is 2Hz, and during the frequency ramp-up control, the frequency per unit time increases by 1Hz.

[0063] Frequency limit control means that when the whole machine current exceeds the corresponding frequency limit current or the compressor phase current exceeds the corresponding frequency limit current, the compressor frequency is no longer allowed to increase.

[0064] Frequency reduction control means that when the whole machine current exceeds the corresponding frequency reduction current or the compressor phase current exceeds the corresponding frequency reduction current, the compressor frequency needs to be controlled to decrease.

[0065] In addition, when the whole machine current exceeds the corresponding shutdown current or the compressor phase current exceeds the corresponding shutdown current, the whole machine stops running.

[0066] To solve the problems existing after the existing defrosting. The prior art discloses a control method for an air-conditioning system, which includes: a detection step for detecting the operating mode of the air-conditioning system, the outdoor ambient temperature Touter loop, and the indoor ambient temperature Tinner loop; a judgment step for judging whether the operating mode has been changed to the heating mode, and judging whether Touter loop is less than A, where A is a constant; and a control step for controlling the fourth throttling device to be opened when the operating mode has been changed to the heating mode, and Touter loop < A, and controlling the opening of the fourth throttling device to be reduced when it is detected that Tset - Tinner loop > C; if it is detected that Tset - Tinner loop < D, controlling the opening of the fourth throttling device to be increased, where C and D are both constants. Through the present invention, the indoor temperature fluctuation during the defrosting period of the entire air-conditioning system is small, the time for resuming heating is short, and the heating can be quickly resumed, effectively ensuring sustainable indoor heating. The indoor unit described in this patent includes a heat exchanger 2 capable of heating during defrosting and a heat exchanger 1 capable of cooling. A second throttling device is also provided in connection with the heat exchanger 2, and a third throttling device is also provided in connection with the heat exchanger 1. In the heating mode or the cooling mode, the control step further controls the opening of both the second throttling device and the third throttling device. This solution adds a heating heat exchanger to heat the indoor unit during defrosting, overcoming the defects of existing air conditioners in that the indoor temperature fluctuates greatly during defrosting, the time required to resume heating is long, and sustainable heating cannot be guaranteed indoors. However, the piping is complex and the cost is high.

[0067] Another prior art provides a heating and defrost control method for an air conditioner, an air conditioner, and a storage medium. This method, after the compressor exits defrosting mode and rapidly ramps up to the heating startup frequency, inserts a slow ramp-up to a first, low frequency and maintains the frequency for a second predetermined time. This mitigates the problem of rapid refrigerant pressure changes in the pipeline caused by rapid compressor startup. This prevents excessive pressure differentials between the expansion valve inlet and outlet, leading to excessively low refrigerant temperature at the expansion valve outlet and causing solidification of compressor lubricant oil mixed with the refrigerant, which can lead to pipeline blockage and heating failure. However, the compressor startup is slow, impacting indoor comfort.

[0068] In summary, existing heat pump air conditioners, when operating in low-temperature conditions such as below 5°C and in heating mode, achieve defrost function through the reversing method of the four-way valve. During the defrosting process, the indoor pipe temperature drops rapidly from over 30°C to around -30°C in a short period of time. After the defrosting is completed, the compressor stops and then resumes operation, and the four-way valve is reversed. In order to prevent cold air from blowing out, the indoor unit is equipped with an anti-cold wind control, so that the inner pipe temperature must reach around 40°C before the fan is started. However, the stopping of the indoor fan will cause the load of the outdoor unit to increase rapidly, and the compressor phase current and the whole machine current will increase rapidly, which can easily trigger the current ramp-up and frequency limiting. The limited compressor frequency will affect the increase in the temperature of the inner pipe, delaying the time to exit the anti-cold wind control and reducing the low-temperature heating capacity.

[0069] To solve the above problems, refer to Figure 1 The embodiment of the present application provides a method for controlling a heat pump air conditioner, wherein the heat pump air conditioner uses a four-way valve for defrosting, and the method includes:

[0070] S11: When the heat pump air conditioner is defrosted and in heating mode, the outdoor ambient temperature is obtained by a sensor, or obtained through networking, or obtained through communication with other devices capable of obtaining the outdoor ambient temperature.

[0071] S12: When the outdoor ambient temperature is lower than a first preset outdoor ambient temperature, the normal control mode is switched to the compressor frequency compensation control mode;

[0072] In the compressor frequency compensation control mode, if the target current is greater than the corresponding first frequency ramp-up current, the compressor is subjected to frequency ramp-up control, wherein the first frequency ramp-up current is greater than the second frequency ramp-up current, wherein the second frequency ramp-up current is the frequency ramp-up current in the normal control mode.

[0073] That is, the present application is a control solution applied to low-temperature heating conditions (outdoor ambient temperature is less than a first preset outdoor ambient temperature) after defrosting is completed by reversing the four-way valve.

[0074] It should be noted that, generally, when the indoor pipe temperature reaches the set pipe temperature threshold for cold wind prevention, the compressor frequency compensation control mode is exited and the normal control mode is entered. The normal control mode refers to the control mode of the prior art and will not be described in detail here.

[0075] When the outdoor ambient temperature is lower than a first preset outdoor ambient temperature, entering the compressor frequency compensation control mode from the normal control mode includes:

[0076] When the outdoor ambient temperature is lower than the first preset outdoor ambient temperature and greater than or equal to the second preset outdoor ambient temperature, the normal control mode enters the first compressor frequency compensation control mode;

[0077] When the outdoor ambient temperature is lower than the second preset outdoor ambient temperature, the normal control mode enters the second compressor frequency compensation control mode;

[0078] Compared to the first compressor frequency compensation control mode, the second compressor frequency compensation control mode does not implement frequency limiting or frequency reduction control on the compressor frequency. This is because when the outdoor ambient temperature is lower, the compressor needs to reach the target frequency more quickly. At this time, due to the low outdoor ambient temperature, even without frequency limiting or frequency reduction control, the compressor will not be damaged.

[0079] As a preferred implementation method of the embodiment of the present application, the compensation threshold is determined based on the indoor pipe temperature, wherein the higher the indoor pipe temperature, the smaller the compensation threshold; it should be noted that the compensation threshold is a positive value.

[0080] The second current threshold of the target current is compensated based on the compensation threshold to obtain the first current threshold of the same target current, wherein the second current threshold is any one of the frequency ramp-up current, frequency limiting current, and frequency reduction current of the target current in the normal control mode (i.e., the factory limit value), and the first current threshold is any one of the frequency ramp-up current, frequency limiting current, and frequency reduction current of the same target current in the compressor frequency compensation control mode. For the same target current, the frequency reduction current > the frequency limiting current > the frequency ramp-up current.

[0081] The first current threshold of the same target current is obtained by compensating the second current threshold of the target current based on the compensation threshold as follows:

[0082] First frequency ramp-up current = second frequency ramp-up current + compensation threshold;

[0083] First frequency limiting current = second frequency limiting current + compensation threshold;

[0084] The first frequency reduction current=the second frequency reduction current+the compensation threshold.

[0085] The first frequency ramp-up current, the first frequency limiting current, and the first frequency reduction current are the first current thresholds; the first frequency ramp-up current, the second frequency limiting current, and the second frequency reduction current are the second current thresholds. It is understood that the compensation thresholds corresponding to different types of currents may be the same or different.

[0086] In normal mode, if the target current exceeds the second current threshold, the compressor may overheat and potentially damage it. Therefore, a second current threshold is set at the factory. When the target current exceeds the second current threshold, frequency ramp-up control, frequency limiting control, or frequency reduction control are implemented. However, when the outdoor ambient temperature is low, the compressor will generate less heat after startup. Therefore, the second current threshold can be appropriately increased, compensating for the first current threshold.

[0087] In actual control, if the control effect is not considered, the compensation threshold value may not be determined according to the indoor pipe temperature, and a fixed compensation threshold value may be directly used.

[0088] In addition, the target current is one of the whole machine current and the compressor phase current;

[0089] The compensation threshold corresponding to the total machine current is less than or equal to the compensation threshold corresponding to the compressor phase current. In actual use, the compressor phase current rises faster. If the compensation threshold is set too low, the compressor frequency rise time will be shorter. Therefore, when performing compensation, the compensation threshold for the compressor phase current is set higher than the compensation threshold for the total machine current.

[0090] As a preferred implementation method of the present application: when the indoor pipe temperature reaches the cold wind prevention exit set pipe temperature threshold, the internal fan is controlled to start, and the first compressor frequency compensation control mode is exited after a preset delay.

[0091] In addition, in the second compressor frequency compensation control mode, the first frequency ramp-up current of the target current is a difference between the shutdown current of the same target current and a preset correction value.

[0092] As a preferred implementation of the embodiment of the present application, when the difference between the target frequency and the compressor frequency is less than or equal to a preset difference, if the compressor performs slow frequency increase control, the indoor fan is controlled based on the indoor pipe temperature;

[0093] The control of the indoor fan based on the indoor pipe temperature includes:

[0094] When the indoor pipe temperature is lower than the first preset indoor pipe temperature, the indoor fan is controlled to be prohibited from running to prevent cold wind.

[0095] When the indoor pipe temperature is greater than or equal to the first preset indoor pipe temperature and less than or equal to the second preset indoor pipe temperature, the indoor fan is controlled to run at a preset speed; wherein the preset speed is a lower wind speed.

[0096] When the indoor pipe temperature is greater than the second preset indoor pipe temperature, the indoor fan is controlled based on actual demand.

[0097] As a preferred implementation of the embodiment of the present application, after defrosting is completed, the compressor stops running and the opening of the electronic expansion valve is controlled to the maximum opening;

[0098] After the compressor stops for a specified period of time, the four-way valve is controlled to reverse, and the compressor is controlled to start running, and the operating frequency is recorded at the same time;

[0099] Start timing when the operating frequency reaches a preset operating frequency;

[0100] When the timing duration is equal to the preset duration, the opening degree of the electronic expansion valve is adjusted according to actual demand conditions.

[0101] The heat pump air conditioner control method provided in the embodiment of the present application adopts a four-way valve reversing method for defrosting. After the heat pump air conditioner is defrosted, the outdoor ambient temperature is obtained. When the outdoor ambient temperature is lower than the first preset outdoor ambient temperature, the normal control mode enters the compressor frequency compensation control mode. In the compressor frequency compensation control mode, the second frequency ramp-up current is compensated to obtain the first frequency ramp-up current. In this way, when the target current is greater than the second frequency ramp-up current, the compressor will not be subjected to frequency ramp-up control, thereby increasing the frequency increase space of the compressor. Moreover, when the target current reaches the second current threshold value under the normal control mode, the frequency limiting or frequency reduction control will not be directly performed. This can ensure that the heat pump air conditioner improves the heating capacity and reliability after defrosting when operating in low-temperature conditions for heating, thereby improving user comfort.

[0102] In order to further illustrate the present application solution, a specific implementation method is provided below. Figure 2 As shown:

[0103] 1. After the whole machine defrosts, the heating operation is resumed, and the T outdoor environment value, T indoor pipe temperature value, and T indoor ambient temperature value are obtained; based on the ambient temperature and pipe temperature values, the whole machine current, phase current ramp-up, current limit / frequency reduction threshold, and the compressor control strategy are adjusted.

[0104] Control logic such as Figure 3 As shown:

[0105] 1.1 When the outdoor environmental value T is less than the outer ring trigger threshold 1 (typical value 5°C), the following compensation operations are performed. In low-temperature conditions, the frost on the outdoor unit is thick and the defrosting time is long. The temperature of the inner pipe also drops significantly during defrosting. Additionally, the whole-machine current, phase current slow rise, limit / down-frequency current threshold, and compressor up-frequency rate are adjusted and corrected in intervals based on the value of the indoor pipe temperature T. <​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​1.2 When the outdoor environmental value < the outer ring trigger threshold 2 (typical value -2°C), after the defrosting ends and before the compressor starts and the indoor fan exits the cold wind prevention control stage, to quickly reach the target frequency, cancel the frequency limit and down-frequency control of the whole machine current and the compressor phase current on the compressor, and retain the protection shutdown and slow frequency increase control. At the same time, adjust the slow frequency increase current threshold to the shutdown current - correction value 1 (typical value 1A). Canceling the limit and down-frequency and slowly increasing the frequency through the shutdown current setting of the whole machine is for the stability of the system, to avoid the rapid increase in frequency due to the rapid release of current limit at this time. <00002 = <00002 =

[0117] 2. Dynamically adjust the cold wind prevention exit start threshold according to the compressor frequency, indoor pipe temperature, and indoor ambient temperature. <00002 = <00002 =

[0118] 2.1 The compressor operating frequency ≥ the target frequency - 10Hz. If it meets the condition for entering the slow compressor frequency increase control and the indoor pipe temperature T < 37°C, the cold wind prevention indoor fan is prohibited from running. When the indoor pipe temperature T < 42°C, the indoor fan runs at low speed. That is, when the indoor pipe temperature is between 37 - 42°C, it runs at low speed; after it is greater than 42°C, it is controlled according to requirements. <00002 = <00002 =

[0119] 3. Adjust the electronic expansion valve opening control strategy according to the compressor switch state, real-time operating frequency value, and exhaust temperature to avoid system oil blockage. As <00002 = Figure 4 shown, after the defrosting ends, the compressor stops running, the electronic expansion valve opens to the maximum opening (typical value 480P). After the compressor stops for a period of time, the four-way valve reverses. The compressor starts running and records the running time or running frequency. When the compressor reaches the set frequency value and runs stably for 30S, the electronic expansion valve starts to adjust according to the actual demand (generally adjusted according to the target exhaust). It should be emphasized that the difference here from the traditional control is only in the control of the electronic expansion valve. <00002 = <00002 =

[0120] The solution of this application provides a control method after the defrosting ends under the low-temperature heating condition, which can quickly increase the indoor pipe temperature, shorten the cold wind prevention time, reduce the risk of oil blockage, and improve the ultra-low temperature heating capacity and user comfort of the whole machine. Obtain the outdoor environmental temperature, indoor environmental temperature, indoor coil temperature, input voltage and current of the whole machine, and compressor phase current of the variable-frequency air conditioner. When the whole machine operates in the low-temperature heating mode and enters the defrosting control, after the defrosting ends, adjust the original frequency control strategy of the compressor according to the detected state. According to the indoor coil temperature and the outer ring temperature, adjust the slow increase and limit frequency thresholds of the whole machine current and the compressor phase current. Before the indoor coil temperature reaches the condition for starting the indoor fan, correct the slow increase and limit frequency thresholds of the current, so that the compressor frequency can smoothly rise to the target frequency value in this stage. Dynamically adjust the cold wind prevention exit start threshold according to the compressor frequency, indoor pipe temperature, and indoor ambient temperature. After the defrosting ends, dynamically adjust the opening of the electronic expansion valve according to the operating state and running time of the compressor to ensure the smooth flow of the refrigerant and avoid the freezing of the refrigeration oil at the valve and blocking the electronic expansion valve.

[0121] Able to solve the following technical problems:

[0122] 1. In low-temperature heating conditions, after defrosting, the indoor unit pipe temperature rises slowly, and the cold wind protection cycle is long, resulting in reduced heating capacity and a long time to restore heating.

[0123] 2. In low-temperature heating conditions, after defrosting, the heating and cold wind prevention load is heavy. The rapid increase in the whole machine current and the compressor phase current can easily trigger a slow frequency increase and frequency limiting, resulting in a decrease in heating capacity and a long time to resume heating, affecting comfort.

[0124] 3. Under low temperature conditions, the refrigerant and refrigeration oil have poor mutual solubility, which may condense or solidify and cause blockage, resulting in the refrigerant being unable to flow normally and causing system pressure imbalance, which in turn causes problems such as low low pressure, abnormal suction and exhaust temperatures, etc.

[0125] In low-temperature heating operation, when there is no room for optimization of the existing defrost time and the number of times the defrost is entered, improving the heating capacity and reliability of the heat pump air conditioner after defrosting is important for improving the low-temperature heating capacity of the entire machine and user comfort.

[0126] Based on the same inventive concept, Figure 5 As shown, the present application also provides a heat pump air conditioner control device 50, wherein the heat pump air conditioner adopts a four-way valve reversing to perform defrosting, and the heat pump air conditioner control device 50 includes:

[0127] The outdoor ambient temperature acquisition module 51 is used to acquire the outdoor ambient temperature when the heat pump air conditioner is defrosted and in heating mode; the outdoor ambient temperature is acquired through a sensor, or acquired through networking, or acquired through communication with other devices that can acquire the outdoor ambient temperature.

[0128] a compensation control mode entry module 52 for entering the compressor frequency compensation control mode from the normal control mode when the outdoor ambient temperature is lower than a first preset outdoor ambient temperature;

[0129] In the compressor frequency compensation control mode, if the target current is greater than the corresponding first frequency ramp-up current, the compressor is subjected to frequency ramp-up control, wherein the first frequency ramp-up current is greater than the second frequency ramp-up current, wherein the second frequency ramp-up current is the frequency ramp-up current in the normal control mode.

[0130] That is, the present application is a control solution applied to low-temperature heating conditions (outdoor ambient temperature is less than a first preset outdoor ambient temperature) after defrosting is completed by reversing the four-way valve.

[0131] It should be noted that, generally, when the indoor pipe temperature reaches the set pipe temperature threshold for cold wind prevention, the compressor frequency compensation control mode is exited and the normal control mode is entered. The normal control mode refers to the control mode of the prior art and will not be described in detail here.

[0132] When the outdoor ambient temperature is lower than a first preset outdoor ambient temperature, entering the compressor frequency compensation control mode from the normal control mode includes:

[0133] When the outdoor ambient temperature is lower than the first preset outdoor ambient temperature and greater than or equal to the second preset outdoor ambient temperature, the normal control mode enters the first compressor frequency compensation control mode;

[0134] When the outdoor ambient temperature is lower than the second preset outdoor ambient temperature, the normal control mode enters the second compressor frequency compensation control mode;

[0135] Compared with the first compressor frequency compensation control mode, in the second compressor frequency compensation control mode, the frequency limiting control and the frequency reducing control are not performed on the compressor frequency.

[0136] As a preferred implementation method of the embodiment of the present application, the compensation threshold is determined based on the indoor pipe temperature, wherein the higher the indoor pipe temperature, the smaller the compensation threshold; it should be noted that the compensation threshold is a positive value.

[0137] The second current threshold of the target current is compensated based on the compensation threshold to obtain the first current threshold of the same target current, wherein the second current threshold is any one of the frequency ramp-up current, frequency limiting current, and frequency reduction current of the target current in the normal control mode, and the first current threshold is any one of the frequency ramp-up current, frequency limiting current, and frequency reduction current of the same target current in the compressor frequency compensation control mode.

[0138] The first current threshold of the same target current is obtained by compensating the second current threshold of the target current based on the compensation threshold as follows:

[0139] First frequency ramp-up current = second frequency ramp-up current + compensation threshold;

[0140] First frequency limiting current = second frequency limiting current + compensation threshold;

[0141] The first frequency reduction current=the second frequency reduction current+the compensation threshold.

[0142] The first frequency ramp-up current, the first frequency limiting current, and the first frequency reduction current are the first current thresholds; the first frequency ramp-up current, the second frequency limiting current, and the second frequency reduction current are the second current thresholds. It is understood that the compensation thresholds corresponding to different types of currents may be the same or different.

[0143] In actual control, if the control effect is not considered, the compensation threshold value may not be determined according to the indoor pipe temperature, and a fixed compensation threshold value may be directly used.

[0144] In addition, the target current is one of the whole machine current and the compressor phase current;

[0145] The compensation threshold corresponding to the whole machine current is less than or equal to the compensation threshold corresponding to the compressor phase current.

[0146] As a preferred implementation method of the present application: when the indoor pipe temperature reaches the cold wind prevention exit set pipe temperature threshold, the internal fan is controlled to start, and the first compressor frequency compensation control mode is exited after a preset delay.

[0147] In addition, in the second compressor frequency compensation control mode, the first frequency ramp-up current of the target current is a difference between the shutdown current of the same target current and a preset correction value.

[0148] As a preferred implementation of the embodiment of the present application, when the difference between the target frequency and the compressor frequency is less than or equal to a preset difference, if the compressor performs slow frequency increase control, the indoor fan is controlled based on the indoor pipe temperature;

[0149] The control of the indoor fan based on the indoor pipe temperature includes:

[0150] When the indoor pipe temperature is lower than the first preset indoor pipe temperature, the indoor fan is controlled to be prohibited from running to prevent cold wind.

[0151] When the indoor pipe temperature is greater than or equal to the first preset indoor pipe temperature and less than or equal to the second preset indoor pipe temperature, the indoor fan is controlled to run at a preset speed; wherein the preset speed is a lower wind speed.

[0152] When the indoor pipe temperature is greater than the second preset indoor pipe temperature, the indoor fan is controlled based on actual demand.

[0153] As a preferred implementation of the embodiment of the present application, after defrosting is completed, the compressor stops running and the opening of the electronic expansion valve is controlled to the maximum opening;

[0154] After the compressor stops for a specified period of time, the four-way valve is controlled to reverse, and the compressor is controlled to start running, and the operating frequency is recorded at the same time;

[0155] Start timing when the operating frequency reaches a preset operating frequency;

[0156] When the timing duration is equal to the preset duration, the opening degree of the electronic expansion valve is adjusted according to actual demand conditions.

[0157] The heat pump air conditioner control device provided in the embodiment of the present application adopts a four-way valve reversing for defrosting. After the heat pump air conditioner is defrosted, the outdoor ambient temperature is obtained. When the outdoor ambient temperature is lower than the first preset outdoor ambient temperature, the normal control mode enters the compressor frequency compensation control mode. In the compressor frequency compensation control mode, the second frequency ramp-up current is compensated to obtain the first frequency ramp-up current. In this way, when the target current is greater than the second frequency ramp-up current, the compressor will not be subjected to frequency ramp-up control, thereby increasing the frequency increase space of the compressor. Moreover, when the target current reaches the second current threshold value under the normal control mode, the frequency limiting or frequency reduction control will not be directly performed. This can ensure that the heat pump air conditioner improves the heating capacity and reliability after defrosting when operating in low-temperature conditions for heating, thereby improving user comfort.

[0158] Based on the same inventive concept, Figure 6 As shown, the present application also provides a heat pump air conditioner control system 60, comprising:

[0159] at least one processor 61 and at least one memory 62;

[0160] The memory stores executable instructions of the processor;

[0161] The processor is configured to execute the heat pump air conditioner control method provided by the above embodiment.

[0162] The heat pump air conditioner control system provided by the embodiment of the present application stores executable instructions of the processor in a memory. When the executable instructions are executed, the processor can obtain the outdoor ambient temperature after the heat pump air conditioner is defrosted. When the outdoor ambient temperature is lower than the first preset outdoor ambient temperature, the processor enters the compressor frequency compensation control mode from the normal control mode. In the compressor frequency compensation control mode, the second frequency ramp-up current is compensated to obtain the first frequency ramp-up current. In this way, when the target current is greater than the second frequency ramp-up current, the compressor will not be subjected to frequency ramp-up control, thereby increasing the frequency increase space of the compressor. Moreover, when the target current reaches the second current threshold value under the normal control mode, frequency limiting or frequency reduction control will not be directly performed, thereby ensuring that the heat pump air conditioner improves the heating capacity and reliability after defrosting when operating in low-temperature conditions, thereby improving user comfort.

[0163] Based on the same inventive concept, the present application also provides a heat pump air conditioner, which applies the heat pump air conditioner control method provided in the above embodiment.

[0164] The heat pump air conditioner provided in the embodiment of the present application, by applying the heat pump air conditioner control method provided in the above embodiment, can obtain the outdoor ambient temperature after the heat pump air conditioner defrosts, and when the outdoor ambient temperature is lower than the first preset outdoor ambient temperature, enter the compressor frequency compensation control mode from the normal control mode. In the compressor frequency compensation control mode, the second frequency ramp-up current is compensated to obtain the first frequency ramp-up current, so that when the target current is greater than the second frequency ramp-up current, the compressor will not be subjected to frequency ramp-up control, thereby increasing the frequency increase space of the compressor. Moreover, when the target current reaches the second current threshold value under the normal control mode, frequency limiting or frequency reduction control will not be directly performed, thereby ensuring that the heat pump air conditioner improves the heating capacity and reliability after defrosting when operating in low-temperature heating conditions, thereby improving user comfort.

[0165] It should be noted that, in the description of this application, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0166] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

Claims

1. A heat pump air conditioner control method, characterized in that: The heat pump air conditioner uses a four-way valve to perform defrosting, and the method includes: When the heat pump air conditioner completes defrosting and operates in a heating mode, obtaining the outdoor ambient temperature; When the outdoor ambient temperature is lower than a first preset outdoor ambient temperature, the normal control mode enters the compressor frequency compensation control mode; In the compressor frequency compensation control mode, if the target current is greater than the corresponding first frequency ramp-up current, the compressor is subjected to frequency ramp-up control, wherein the first frequency ramp-up current is greater than the second frequency ramp-up current, wherein the second frequency ramp-up current is the frequency ramp-up current in the normal control mode.

2. The method according to claim 1, characterized in that When the outdoor ambient temperature is lower than a first preset outdoor ambient temperature, entering the compressor frequency compensation control mode from the normal control mode includes: When the outdoor ambient temperature is lower than the first preset outdoor ambient temperature and greater than or equal to the second preset outdoor ambient temperature, the normal control mode enters the first compressor frequency compensation control mode; When the outdoor ambient temperature is lower than the second preset outdoor ambient temperature, the normal control mode enters the second compressor frequency compensation control mode; Compared with the first compressor frequency compensation control mode, in the second compressor frequency compensation control mode, the frequency limiting control and the frequency reducing control are not performed on the compressor frequency.

3. The method according to claim 2, characterized in that Also includes: In the first compressor frequency compensation control mode, a compensation threshold is determined based on the indoor pipe temperature, wherein the higher the indoor pipe temperature is, the smaller the compensation threshold is; The second current threshold of the target current is compensated based on the compensation threshold to obtain the first current threshold of the same target current, wherein the second current threshold is any one of the frequency ramp-up current, frequency limiting current, and frequency reduction current of the target current in the normal control mode, and the first current threshold is any one of the frequency ramp-up current, frequency limiting current, and frequency reduction current of the same target current in the compressor frequency compensation control mode. For the same target current, the frequency reduction current > the frequency limiting current > the frequency ramp-up current.

4. The method according to claim 3, wherein: The target current is one of the whole machine current and the compressor phase current; The compensation threshold corresponding to the whole machine current is less than or equal to the compensation threshold corresponding to the compressor phase current.

5. The method according to claim 3, characterized in that Also includes: When the indoor pipe temperature reaches the cold wind prevention exit set pipe temperature threshold, the internal fan is controlled to start, and the first compressor frequency compensation control mode is exited after a preset delay.

6. The method according to claim 2, characterized in that Also includes: In the first compressor frequency compensation control mode, the first frequency ramp-up current of the target current is a difference between a shutdown current of the same target current and a preset correction value.

7. The method according to claim 1, characterized in that Also includes: When the difference between the target frequency and the compressor frequency is less than or equal to the preset difference, if the compressor performs slow frequency increase control, the indoor fan is controlled based on the indoor pipe temperature; The control of the indoor fan based on the indoor pipe temperature includes: When the indoor pipe temperature is lower than a first preset indoor pipe temperature, the indoor fan is controlled to be prohibited from running; When the indoor pipe temperature is greater than or equal to the first preset indoor pipe temperature and less than or equal to the second preset indoor pipe temperature, controlling the indoor fan to operate at a preset speed; When the indoor pipe temperature is greater than the second preset indoor pipe temperature, the indoor fan is controlled based on actual demand.

8. The method according to claim 1, characterized in that Also includes: After defrosting is completed, the compressor stops running and the electronic expansion valve is controlled to open to the maximum; After the compressor stops for a specified period of time, the four-way valve is controlled to reverse, and the compressor is controlled to start running, and the operating frequency is recorded at the same time; Start timing when the operating frequency reaches a preset operating frequency; When the timing duration is equal to the preset duration, the opening degree of the electronic expansion valve is adjusted according to actual demand conditions.

9. A heat pump air conditioner control device, characterized in that: The heat pump air conditioner adopts a four-way valve reversing method to perform defrosting, and the device comprises: An outdoor ambient temperature acquisition module, configured to acquire the outdoor ambient temperature when the heat pump air conditioner completes defrosting and operates in a heating mode; a compensation control mode entry module, configured to enter the compressor frequency compensation control mode from the normal control mode when the outdoor ambient temperature is lower than a first preset outdoor ambient temperature; In the compressor frequency compensation control mode, if the target current is greater than the corresponding first frequency ramp-up current, the compressor is subjected to frequency ramp-up control, wherein the first frequency ramp-up current is greater than the second frequency ramp-up current, wherein the second frequency ramp-up current is the frequency ramp-up current in the normal control mode.

10. A heat pump air conditioner control system, characterized in that: include: at least one processor and at least one memory; The memory stores executable instructions of the processor; The processor is configured to execute the method according to any one of claims 1 to 8.

11. A heat pump air conditioner, characterized in that: The heat pump air conditioner applies the method according to any one of claims 1 to 8.

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