Anti-freezing control device, method, air conditioner and computer readable storage medium

Abstract

The application provides a freeze-proof control device, method, air conditioner and computer readable storage medium. The device comprises a detection module, which detects outdoor environment temperature T2, outdoor unit coil temperature T1 and current exhaust temperature Tpc of the air conditioner in real time; a recording module, which records T2, T1, Tpc, Tpmax and DeltaT2; a judgment module, which judges whether the air conditioner meets freeze-proof entering conditions, the freeze-proof entering conditions comprising: a first freeze-proof condition: (Tpmax-Tpc) / (tpc-tpmax) >= k1, or Tpmax / Tpc >= s1; a second freeze-proof condition: on the basis of meeting the first freeze-proof condition, T1+DeltaT2 >= T2+m, and DeltaTpc / DeltaT <= k2 for a duration t1; and a third freeze-proof condition: when the first freeze-proof condition and the second freeze-proof condition are not met at the same time, |Tpc-T1| <= n1 for a duration t2; and an execution module, which controls whether the air conditioner enters a freeze-proof protection mode. The application can make the air conditioner enter the freeze-proof protection mode in time, so that the air conditioner can run safely and stably for the air conditioner which cannot communicate between the indoor unit and the outdoor unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of air conditioners, in particular to a freeze prevention control device and method, an air conditioner and a computer readable storage medium. BACKGROUND

[0002] When the air conditioner is started to run in cooling mode at a low outside ambient temperature, the indoor unit coil is prone to frost formation, which will reduce the indoor air volume and affect the cooling capacity, and even cause the compressor to be damaged by liquid strike. The existing low-temperature refrigeration indoor unit coil freeze protection technology mostly detects when the indoor coil temperature reaches a certain threshold, sends an instruction to the indoor / outdoor unit to enter the freeze protection, and when the indoor coil temperature rises to another threshold, the protection is exited.

[0003] However, the entry / exit of freeze protection by judging the indoor coil temperature may cause the evaporator to be seriously iced up when the protection is entered, and the protection is not entered in time, or the evaporator is not iced up but the protection is entered. Similarly, when the protection is exited, the air conditioner may still be in the protection state and cannot supply cooling in time due to the lack of timely judgment. Furthermore, the indoor coil temperature sensor increases the cost of the air conditioner, and the existing related freeze prevention technology has limitations: the indoor coil temperature state of the air conditioner without communication between the indoor unit and the outdoor unit cannot be transmitted to the outdoor unit, so the freeze protection cannot be performed. SUMMARY

[0004] To solve the above problems, the present application provides a freeze prevention control device and method, an air conditioner and a computer readable storage medium, which comprehensively detects the current outdoor unit exhaust temperature Tpc, the outdoor environment temperature T2 and the outdoor unit coil temperature T1, judges the indoor unit coil state, and for the air conditioner without communication between the indoor unit and the outdoor unit, can enter the freeze protection mode in time, so that the air conditioner can run safely and stably.

[0005] The application provides a freeze-proof control device of an air conditioner, which comprises a detection module, which detects outdoor environment temperature T2, outdoor unit coil temperature T1 and current outdoor unit exhaust temperature Tpc of the air conditioner in real time; a recording module, which records the outdoor environment temperature T2, the outdoor unit coil temperature T1, the current outdoor unit exhaust temperature Tpc, maximum outdoor unit exhaust temperature Tpmax and outdoor environment temperature change amount AT2; a judgment module, which is in communication connection with the recording module and the detection module, and judges whether the air conditioner meets freeze-proof entering conditions, the freeze-proof entering conditions comprising: a first freeze-proof condition, that is, a change rate of the current outdoor unit exhaust temperature Tpc relative to Tpmax (Tpmax-Tpc) / (tpc-tpmax) is greater than or equal to a first preset rate k1, or a ratio of the maximum outdoor unit exhaust temperature to the current outdoor unit exhaust temperature Tpmax / Tpc is greater than or equal to a first preset proportion s1; a second freeze-proof condition, that is, on the basis of meeting the first freeze-proof condition, a sum of the outdoor unit coil temperature and the outdoor environment temperature change amount T1+AT2 is greater than or equal to T2+m, and ATpc / At is less than or equal to a second preset rate k2 for a first preset time duration t1; and a third freeze-proof condition, that is, when the first freeze-proof condition and the second freeze-proof condition are not met at the same time, an absolute value of a difference between the current outdoor unit exhaust temperature and the outdoor unit coil temperature |Tpc-T1| is less than or equal to n1 for a second preset time duration t2; tpc is a time corresponding to the current exhaust temperature, tpmax is a time corresponding to the maximum exhaust temperature; AT2 is a change amount of the outdoor environment temperature, and m is a real number; and an execution module, which is in communication connection with the judgment module, and controls whether the air conditioner enters a freeze-proof protection mode according to a judgment result of the judgment module.

[0006] When the outdoor environment temperature is low, the current outdoor unit exhaust temperature Tpc will increase and reach a maximum value when the low-temperature refrigeration is just started, at this time, if the indoor environment temperature is also low, the heat exchange efficiency of the indoor unit coil will be low, which leads to that the refrigerant in the indoor unit cannot be completely evaporated and overheated, and the liquid refrigerant will return to the outdoor unit, which leads to that the outdoor unit coil condensing pressure and temperature decrease, and the current outdoor unit exhaust temperature Tpc will always decrease (the initial decrease rate is very fast, (Tpmax-Tpc) / (tpc-tpmax)≥k1 or Tpmax / Tpc≥s1), until the indoor unit coil is frozen, the current outdoor unit exhaust temperature Tpc and the outdoor unit coil temperature T1 will tend to be stable; after the indoor unit coil is frozen, the outdoor unit coil temperature T1 is low and tends to be close to the outdoor environment temperature T2 (the outdoor environment temperature T2 may also fluctuate AT2), therefore, by judging (Tpmax-Tpc) / (tpc-tpmax)≥k1 or Tpmax / Tpc≥s1, and T1+AT2≥T2+m, and ATpc / At≤the second preset rate k2 for the first preset time duration t1, whether the indoor unit coil is frozen can be judged.

[0007] |Tpc-T1|≤n1 is to judge the state after the indoor unit icing: the indoor unit icing leads to the low exhaust gas superheat, the outdoor unit coil pressure and the exhaust gas pressure tend to be equal (the pressure corresponds to the saturation temperature), by judging |Tpc-T1|≤n1, the current exhaust gas temperature Tpc of the outdoor unit caused by the soft start of some variable frequency units can be prevented from being always low, which cannot meet the first anti-freezing condition and the second anti-freezing condition. The freezing condition of the indoor unit coil of the air conditioner is judged through the three anti-freezing conditions, the timeliness and accuracy of the judgment are improved, the indoor unit can enter the anti-freezing protection in time, in addition, for the air conditioner whose indoor unit and outdoor unit cannot communicate, the indoor unit can also enter the anti-freezing protection in time, and the operation stability and safety of the air conditioner are improved.

[0008] In the optional technical scheme of the present application, the judgment module is further used to judge whether the air conditioner meets the anti-freezing exit condition, if yes, the execution module controls the air conditioner to exit the anti-freezing protection, and if not, the execution module controls to return to the anti-freezing protection mode; the anti-freezing exit condition is that when the air conditioner enters the anti-freezing protection mode, the exhaust gas temperature Tpf at the time of entering the anti-freezing protection is recorded, if the exhaust gas temperature change rate ΔTpc / Δt≥the third preset rate k3 or Tpf-Tpc≤n2 lasts for the third preset time t3.

[0009] According to the technical scheme, after entering the anti-freezing protection, various conditions need to be considered: 1. the compressor does not stop and the outdoor fan stops running, which leads to the rising of the condensing pressure and the exhaust gas temperature (ΔTpc / Δt≥k3), and the rising of the indoor unit coil evaporation pressure to complete the ice removal; 2. the compressor stops, which leads to the balance of the refrigerant on the high and low pressure sides of the refrigeration system, the low temperature and low pressure refrigerant in the indoor unit is backfilled to the outdoor unit coil, which leads to the falling of Tpc and T1, and after the pressure balance (the liquid refrigerant in the indoor unit coil is completely evaporated, and the indoor unit coil completes the ice removal), the corresponding outdoor unit is that Tpc and T1 will rise again until Tpf-Tpc≤n2, therefore, through the judgment of the anti-freezing exit condition, the air conditioner can be controlled to exit the anti-freezing protection in time and supply cold in time, and the user demand is met.

[0010] In the optional technical scheme of the present application, the operation module is in communication connection with the recording module and the judgment module, the operation module calculates the change rate of the current exhaust gas temperature Tpc of the outdoor unit relative to Tpmax (Tpmax-Tpc) / (tpc-tpmax), calculates the ratio of the maximum exhaust gas temperature of the outdoor unit to the current exhaust gas temperature of the outdoor unit Tpmax / Tpc, calculates the real-time change rate of the current exhaust gas temperature of the outdoor unit ΔTpc / Δt, the sum of the outdoor unit coil temperature and the outdoor environment temperature change amount T1+ΔT2, and the absolute value of the difference between the current exhaust gas temperature of the outdoor unit and the outdoor unit coil temperature |Tpc-T1|, and sends the calculation results to the judgment module.

[0011] According to the technical scheme, the operation efficiency of the anti-freezing control device is improved, and the air conditioner is ensured to operate efficiently and stably.

[0012] In the optional technical scheme of the application, the air conditioner comprises a compressor, and in the anti-freezing protection mode, the compressor operates at a preset frequency or the compressor stops operating.

[0013] According to the technical scheme, the compressor operates at a preset frequency or the compressor stops operating, which can prevent the icing condition of the indoor unit from being more serious and improve the operation safety and stability of the air conditioner.

[0014] The application further provides an anti-freezing control method of an air conditioner, comprising the following steps.

[0015] When the air conditioner operates in a refrigeration mode, the outdoor environment temperature T2 and the outdoor unit coil temperature T1 are detected in real time.

[0016] If T2 is less than or equal to a first preset outdoor temperature Ts, the current outdoor unit exhaust temperature Tpc is detected and recorded, and the maximum outdoor unit exhaust temperature Tpmax is updated;

[0017] It is judged whether the air conditioner meets a first anti-freezing condition; the first anti-freezing condition is that (Tpmax-Tpc) / (tpc-tpmax) is greater than or equal to a first preset rate k1, or Tpmax / Tpc is greater than or equal to a first preset proportion s1, wherein tpc is the time corresponding to the current exhaust temperature, and tpmax is the time corresponding to the maximum exhaust temperature.

[0018] If yes, it is further judged whether the air conditioner meets a second anti-freezing condition; the second anti-freezing condition is that the sum of the outdoor unit coil temperature and the outdoor environment temperature variation T1+ΔT2 is greater than or equal to T2+m, and the outdoor unit exhaust temperature real-time variation rate ΔTpc / Δt is less than or equal to a second preset rate k2 for a first preset time length t1.

[0019] If the second anti-freezing condition is met, the air conditioner is controlled to enter an anti-freezing protection mode.

[0020] If the first anti-freezing condition and the second anti-freezing condition are not met, it is judged whether the air conditioner meets a third anti-freezing condition; the third anti-freezing condition is that |Tpc-T1| is less than or equal to n1 for a second preset time length t2.

[0021] If the third anti-freezing condition is met, the air conditioner is controlled to enter the anti-freezing protection mode.

[0022] In the optional technical scheme of the application, it is further judged whether an anti-freezing exit condition is met, if yes, the anti-freezing protection is exited, and if not, the anti-freezing protection mode is returned.

[0023] The anti-freezing exit condition is: when the air conditioner enters the anti-freezing protection mode, the exhaust temperature Tpf at the time of entering the anti-freezing protection is recorded, and if the exhaust temperature change rate ΔTpc / Δt≥the third preset rate k3 or Tpf-Tpc≤n2 continues for the third preset time t3.

[0024] In the optional technical solution of the present application, the outdoor unit of the air conditioner comprises a compressor, and in the anti-freezing protection mode, the compressor is operated at a preset frequency or the compressor is stopped.

[0025] The present application further provides an air conditioner comprising the anti-freezing control device of the air conditioner.

[0026] The present application further provides a computer readable storage medium comprising a memory and a computer program stored in the memory, and the computer program, when executed, implements the anti-freezing control method of the air conditioner. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Fig. 1 is a structural schematic diagram of the anti-freezing control device of the air conditioner in the embodiment of the present application.

[0028] Figure 2 Fig. 2 is a flow schematic diagram of the anti-freezing control method of the air conditioner in the embodiment of the present application.

[0029] REFERENCE SIGNS

[0030] The detection module 1, the recording module 2, the judging module 3, the execution module 4 and the operation module 5. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0032] For the air conditioner which only outputs 24V electric signals to the indoor unit and the outdoor unit respectively through a temperature controller to control, the indoor unit and the outdoor unit of the air conditioner cannot directly communicate. When the outdoor environment temperature is low, the refrigerant temperature entering the indoor coil is too low to cause the indoor coil to freeze, and the refrigerant cannot be completely evaporated under the condition of low temperature and low pressure of the indoor coil, which even leads to liquid strike of the compressor and damage. However, the signal of the freezing of the indoor coil cannot be sent to the outdoor unit, and the anti-freezing protection cannot be performed.

[0033] As shown in Fig. 1, the anti-freezing control device of the air conditioner comprises a detection module 1, a recording module 2, a judging module 3, an execution module 4 and an operation module 5. Figure 1As shown, the application provides a freeze-proof control device of an air conditioner, which comprises: a detection module 1, which detects outdoor environment temperature T2, outdoor unit coil temperature T1 and current outdoor unit exhaust temperature Tpc of the air conditioner in real time; a recording module 2, which records outdoor environment temperature T2, outdoor unit coil temperature T1, current outdoor unit exhaust temperature Tpc, maximum outdoor unit exhaust temperature Tpmax and outdoor environment temperature change amount ΔT2; a judgment module 3, which is communicatively connected with the recording module 2 and the detection module 1, judges whether the air conditioner is in a low-temperature refrigeration state and whether the air conditioner meets freeze-proof entering conditions, the freeze-proof entering conditions comprising: a first freeze-proof condition: change rate of the current outdoor unit exhaust temperature Tpc relative to Tpmax (Tpmax-Tpc) / (tpc-tpmax)≥first preset rate k1, or ratio of the maximum outdoor unit exhaust temperature to the current outdoor unit exhaust temperature Tpmax / Tpc≥first preset proportion s1; a second freeze-proof condition: on the basis of meeting the first freeze-proof condition, sum of the outdoor unit coil temperature and the outdoor environment temperature change amount T1+ΔT2≥T2+m, and ΔTpc / Δt≤second preset rate k2 for a first preset time duration t1; and a third freeze-proof condition: when the first freeze-proof condition and the second freeze-proof condition are not met at the same time, absolute value of difference between the current outdoor unit exhaust temperature and the outdoor unit coil temperature |Tpc-T1|≤n1 for a second preset time duration t2; tpc is a time corresponding to the current exhaust temperature, tpmax is a time corresponding to the maximum exhaust temperature; ΔT2 is a change amount of the outdoor environment temperature, and m is a real number; and an execution module 4, which is communicatively connected with the judgment module 3, controls whether the air conditioner enters a freeze-proof protection mode according to a judgment result of the judgment module 3.

[0034] In the case of low outdoor environment temperature, the current outdoor unit exhaust temperature Tpc will rise and reach a maximum value when the low-temperature refrigeration is just started, at this time, if the indoor environment temperature is also low, the heat exchange efficiency of the indoor unit coil will be low, which leads to that the refrigerant in the indoor unit cannot be completely evaporated and overheated, liquid refrigerant will return to the outdoor unit, which leads to that the outdoor unit coil condensing pressure and temperature decrease, and the current outdoor unit exhaust temperature Tpc will always decrease (the initial decrease rate is very fast, (Tpmax-Tpc) / (tpc-tpmax)≥k1 or Tpmax / Tpc≥s1), until the indoor unit coil is frozen, the current outdoor unit exhaust temperature Tpc and the outdoor unit coil temperature T1 will tend to be stable; after the indoor unit coil is frozen, the outdoor unit coil temperature T1 is low and tends to be close to the outdoor environment temperature T2 (the outdoor environment temperature T2 may also fluctuate ΔT2), therefore, by judging (Tpmax-Tpc) / (tpc-tpmax)≥k1 or Tpmax / Tpc≥s1 and T1+ΔT2≥T2+m, whether the indoor unit coil is frozen can be comprehensively judged from two aspects of the decrease rate of the outdoor unit exhaust temperature and the outdoor unit coil temperature, and the accuracy of the judgment is improved.

[0035] Further, |Tpc-T1|≤n1 is to judge the state after the indoor unit icing: the indoor unit icing leads to low exhaust gas superheat, and the outdoor unit coil pressure and the exhaust gas pressure tend to be equal (the pressure corresponds to the saturation temperature), and by judging |Tpc-T1|≤n1, the current exhaust gas temperature of the outdoor unit caused by the soft start of some variable frequency units can be prevented

[0036] Tpc is always low, and the first anti-freezing condition and the second anti-freezing condition cannot be met. The present application judges the freezing condition of the indoor unit coil of the air conditioner through the five anti-freezing conditions, improves the timeliness and

[0037] accuracy of the judgment, so that the indoor unit can enter the anti-freezing protection in time, in addition, for the air conditioner whose indoor unit and outdoor unit cannot communicate, the indoor unit can also enter the anti-freezing protection in time, and the running stability and safety of the air conditioner are improved.

[0038] In the preferred embodiment of the present application, the outdoor environment temperature T2≤ the first preset outdoor ring temperature (the "outdoor ring temperature" is the outdoor environment temperature) Ts (preferably, Ts=18℃). Through the above-mentioned manner, when the outdoor environment temperature T2 is lower than 18℃, the exhaust gas temperature Tpc of the outdoor unit and the coil temperature T1 of the outdoor unit are detected, and whether the air conditioner meets the anti-freezing entering condition is judged, the timeliness of the anti-freezing protection of the air conditioner is improved, the state of the indoor unit coil can be judged in time, and the safe and stable operation of the air conditioner is ensured.

[0039] In the preferred embodiment of the present application, the outdoor environment temperature T2≤ the first preset outdoor ring temperature (the "outdoor ring temperature" is the outdoor environment temperature) Ts (preferably, Ts=18℃). Through the above-mentioned manner, when the outdoor environment temperature T2 is lower than 18℃, the exhaust gas temperature Tpc of the outdoor unit and the coil temperature T1 of the outdoor unit are detected, and whether the air conditioner meets the anti-freezing entering condition is judged, the timeliness of the anti-freezing protection of the air conditioner is improved, the state of the indoor unit coil can be judged in time, and the safe and stable operation of the air conditioner is ensured.

[0040] In the specific embodiment of the present application, the detection module 1 comprises a first detection module for detecting the outdoor environment temperature and a second detection module for detecting the coil temperature of the outdoor unit, the first detection module, the second detection module and the running mode detection module are connected to the judgment module 3.

[0041] Further, the detection module 1 further comprises a running mode detection module for detecting the running mode of the air conditioner and sending to the judgment module 3 to judge whether it is in the refrigeration mode, and then executing the anti-freezing judgment in the low-temperature refrigeration mode.

[0042] In the specific embodiment of the present application, the recording module 2 records the current exhaust gas temperature Tpc0 of the outdoor unit in real time to obtain the historical exhaust gas temperature; and the latest current exhaust gas temperature of the outdoor unit is compared with the historical exhaust gas temperature value

[0043] That is, Tpmax can be obtained.

[0044] In the preferred embodiment of the present application, the operation module 5 is in communication connection with the recording module 2 and the judgment module 3, the operation module 5 calculates the change rate of the current exhaust temperature Tpc of the outdoor unit relative to Tpmax, (Tpmax-Tpc) / (tpc-tpmax), calculates the ratio of the maximum exhaust temperature of the outdoor unit to the current exhaust temperature 5 of the outdoor unit, Tpmax / Tpc, calculates the real-time change rate of the current exhaust temperature of the outdoor unit, ΔTpc / Δt, the sum of the change amount of the outdoor unit coil temperature and the outdoor environment temperature, T1+ΔT2, and the absolute value of the difference between the current exhaust temperature of the outdoor unit and the outdoor unit coil temperature, |Tpc-T1|, and sends the calculation results to the judgment module 3. In the above manner, the operation efficiency of the anti-freezing control device can be improved, and the air conditioner can be ensured to operate efficiently and stably.

[0045] In the preferred embodiment of the present application, the judgment module 3 is further used to judge whether the air conditioner meets the anti-freezing exit condition, if yes, the execution module 4 controls the air conditioner to exit the anti-freezing protection, and if not, the execution module 4 controls the air conditioner to return to the anti-freezing protection mode.

[0046] The anti-freezing exit condition is that when the air conditioner enters the anti-freezing protection mode, the exhaust temperature Tpf at the time of entering the anti-freezing protection is recorded (the recording module 2 can also record the exhaust temperature Tpf at the time of entering the anti-freezing protection mode of the air conditioner), and if the exhaust temperature change rate ΔTpc / Δt≥the third preset rate k3 or Tpf-Tpc≤n2 lasts for the third preset time t3.

[0047] In the above manner, after entering the anti-freezing protection, various conditions need to be considered: 1. The compressor does not stop and the outdoor fan stops running, causing the condensing pressure to rise, the exhaust temperature to rise (ΔTpc / Δt≥k3), and the evaporating pressure of the indoor unit coil to rise to complete the deicing; 2. The compressor stops, causing the refrigerant on the high and low pressure sides of the refrigeration system to balance, the low temperature and low pressure refrigerant in the indoor unit to backfill to the outdoor unit coil, causing Tpc and T1 to drop, and after the pressure balances (the liquid refrigerant in the indoor unit coil is completely evaporated, and the indoor unit coil completes the deicing), the corresponding outdoor unit is Tpc and T1 which will rise again until Tpf-Tpc≤n2 is stable, therefore, through the judgment of the anti-freezing exit condition, the air conditioner can be controlled to exit the anti-freezing protection in time and supply cold in time, meeting the user's demand.

[0048] In the preferred embodiment of the present application, the air conditioner comprises a compressor, and in the anti-freezing protection mode, the compressor operates at a preset frequency or the compressor stops operating.

[0049] In the above manner, the compressor operates at a reduced frequency or stops operating, which can prevent the icing condition of the indoor unit from being more serious, and improve the operation safety and stability of the air conditioner.

[0050] In the preferred embodiment of the present application, in the first anti-freezing condition: (Tpmax-Tpc) / (tpc-tpmax)≥k1 (preferably, k1=0.6), or Tpmax / Tpc≥s1 (preferably, s1=2.2).

[0051] In the second anti-freezing condition, T3+ΔT4≥T4+m (preferably, m=0.5), and ΔTpc / Δt≤the second preset rate k2 (preferably, k2=-0.2, the negative value represents a rate decrease) for a first preset time length t1 (preferably, t1=30s).

[0052] In the third anti-freezing condition, |Tpc-T3|≤n1 (preferably, n1=1) for a second preset time length t2 (preferably, t2=10s).

[0053] In the exit freezing protection condition, the exhaust temperature change rate ΔTpc / Δt is greater than or equal to k3 (preferably, k3=+2, the positive value represents a rate increase) or Tpf-Tpc≤n2 (preferably, n2=2) for a third preset time length t3 (preferably, t3=30s).

[0054] In the above manner, the entering / exit function of the anti-freezing protection can be timely entered, so as to ensure that the air conditioner operates efficiently, stably and safely.

[0055] Corresponding to the anti-freezing control device of the air conditioner of the present application, the present application further provides an air conditioner anti-freezing control method, comprising the following steps:

[0056] When the air conditioner is in refrigeration operation, the outdoor environment temperature T2 and the outdoor unit coil temperature T1 are detected in real time;

[0057] If T2≤the first preset outdoor temperature Ts, the current outdoor unit exhaust temperature Tpc is detected and recorded, and the maximum outdoor unit exhaust temperature Tpmax is updated iteratively;

[0058] It is judged whether the air conditioner meets the first anti-freezing condition; the first anti-freezing condition is: (Tpmax-Tpc) / (tpc-tpmax)≥the first preset rate k1, or Tpmax / Tpc≥the first preset ratio s1, wherein tpc is the time corresponding to the current exhaust temperature, and tpmax is the time corresponding to the maximum exhaust temperature;

[0059] If yes, it is further judged whether the air conditioner meets the second anti-freezing condition; the second anti-freezing condition is: the sum of the outdoor unit coil temperature and the outdoor environment temperature change amount T1+ΔT2≥T2+m, and the outdoor unit exhaust temperature real-time change rate ΔTpc / Δt≤the second preset rate k2 for a first preset time length t1;

[0060] If the second anti-freezing condition is met, the air conditioner is controlled to enter an anti-freezing protection mode; the compressor is operated at a preset frequency; the current frequency Fn is reduced to Fn-1 (preferably 0.9*Fn=Fn-1 is rounded up), and if it is a fixed-frequency machine, the compressor is stopped;

[0061] If the first anti-freezing condition and the second anti-freezing condition are not met, it is determined whether the air conditioner meets a third anti-freezing condition; the third anti-freezing condition is that |Tpc-T1|≤n1 for a second preset time t2;

[0062] If the third anti-freezing condition is met, the air conditioner is controlled to enter the anti-freezing protection mode, and if it is met, the anti-freezing protection is entered, and the compressor is stopped;

[0063] In a preferred embodiment of the present application, it is further determined whether an anti-freezing exit condition is met, and if it is met, the anti-freezing protection is exited, and if it is not met, the anti-freezing protection mode is returned;

[0064] The anti-freezing exit condition is that when the air conditioner enters the anti-freezing protection mode, the exhaust temperature Tpf when the anti-freezing protection is entered is recorded, and if the exhaust temperature change rate ΔTpc / Δt≥the third preset rate k3 or Tpf-Tpc≤n2 for a third preset time t3, the anti-freezing protection mode is exited. After the anti-freezing protection mode is exited, the compressor resumes normal frequency operation.

[0065] In a preferred embodiment of the present application, after completing an anti-freezing protection cycle, the above anti-freezing control method is executed in a loop to monitor the indoor coil state in real time, ensure normal operation of the indoor coil, and improve user experience.

[0066] The present application further provides an air conditioner comprising the anti-freezing control device of the air conditioner described above, and the air conditioner with the anti-freezing control device can enter the anti-freezing protection and exit the anti-freezing protection in time when operating at low temperature, thereby improving the stability of the air conditioner operation and the comfort of the user.

[0067] The present application further provides a computer-readable storage medium comprising a memory storing a computer program, and the computer program is executed to perform the anti-freezing control method of the air conditioner described above.

[0068] The above is only a preferred embodiment of the present application, and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A freeze prevention control device for an air conditioner, characterized by comprising: The anti-freezing control device comprises: a detection module, which detects outdoor environment temperature T2, outdoor unit coil temperature T1 and current outdoor unit exhaust temperature Tpc of the air conditioner in real time; a recording module, which records outdoor environment temperature T2, outdoor unit coil temperature T1, current outdoor unit exhaust temperature Tpc, maximum outdoor unit exhaust temperature Tpmax and outdoor environment temperature change amount ΔT2; a judgment module, which is in communication connection with the recording module and the detection module, judges whether the air conditioner is in a low-temperature refrigeration state and judges whether the air conditioner meets anti-freezing entering conditions, the anti-freezing entering conditions comprising: a first anti-freezing condition: change rate of current outdoor unit exhaust temperature Tpc relative to Tpmax (Tpmax-Tpc) / (tpc-tpmax) ≥ first preset rate k1, or ratio of maximum outdoor unit exhaust temperature to current outdoor unit exhaust temperature Tpmax / Tpc ≥ first preset proportion s1; a second anti-freezing condition: on the basis of meeting the first anti-freezing condition, sum of outdoor unit coil temperature and outdoor environment temperature change amount T1+ΔT2 ≥ T2+m, and ΔTpc / Δt ≤ second preset rate k2 for a first preset time length t1; and a third anti-freezing condition: when the first anti-freezing condition and the second anti-freezing condition are not met at the same time, absolute value of difference between current outdoor unit exhaust temperature and outdoor unit coil temperature |Tpc-T1| ≤ n1 for a second preset time length t2; tpc is time corresponding to current exhaust temperature, tpmax is time corresponding to maximum exhaust temperature; ΔT2 is change amount of outdoor environment temperature, and m is a real number; an execution module, which is in communication connection with the judgment module, controls whether the air conditioner enters an anti-freezing protection mode according to a judgment result of the judgment module.

2. The anti-freezing control apparatus of an air conditioner according to claim 1, wherein The judgment module is further used for judging whether the air conditioner meets anti-freezing exiting conditions, and if so, the execution module controls the air conditioner to exit anti-freezing protection, and if not, the execution module controls to return to the anti-freezing protection mode; the anti-freezing exiting conditions being: when the air conditioner enters the anti-freezing protection mode, recording exhaust temperature Tpf at the time of entering the anti-freezing protection, and if exhaust temperature change rate ΔTpc / Δt ≥ third preset rate k3 or Tpf-Tpc ≤ n2 for a third preset time length t3.

3. The anti-freeze control apparatus for an air conditioner according to claim 1, wherein The anti-freezing control device further comprises an operation module, which is in communication connection with the recording module and the judgment module, calculates change rate of current outdoor unit exhaust temperature Tpc relative to Tpmax (Tpmax-Tpc) / (tpc-tpmax), calculates ratio of maximum outdoor unit exhaust temperature to current outdoor unit exhaust temperature Tpmax / Tpc, calculates current outdoor unit exhaust temperature real-time change rate ΔTpc / Δt, calculates sum of outdoor unit coil temperature and outdoor environment temperature change amount T1+ΔT2, and calculates absolute value of difference between current outdoor unit exhaust temperature and outdoor unit coil temperature |Tpc-T1|, and sends calculation results to the judgment module.

4. The anti-freeze control apparatus for an air conditioner according to claim 1, wherein The air conditioner comprises a compressor, and in the anti-freezing protection mode, the compressor is operated at a preset frequency or the compressor is stopped.

5. A freeze prevention control method of an air conditioner, characterized by, The method comprises the following steps: When the air conditioner is operated in a cooling mode, the outdoor ambient temperature T2 and the outdoor unit coil temperature T1 are detected in real time; If T2≤Ts, the current outdoor unit exhaust temperature Tpc is detected and recorded, and the maximum outdoor unit exhaust temperature Tpmax is updated; It is determined whether the air conditioner satisfies a first anti-freezing condition; the first anti-freezing condition is that (Tpmax-Tpc) / (tpc-tpmax)≥k1 or Tpmax / Tpc≥s1, wherein tpc is the time corresponding to the current exhaust temperature, and tpmax is the time corresponding to the maximum exhaust temperature; If yes, it is further determined whether the air conditioner satisfies a second anti-freezing condition; the second anti-freezing condition is that the sum of the outdoor unit coil temperature and the outdoor ambient temperature variation T1+ΔT2≥T2+m, and the outdoor unit exhaust temperature real-time variation rate ΔTpc / Δt≤k2 for a first preset time duration t1; If the second anti-freezing condition is satisfied, the air conditioner is controlled to enter an anti-freezing protection mode; If the first anti-freezing condition and the second anti-freezing condition are not satisfied, it is determined whether the air conditioner satisfies a third anti-freezing condition; the third anti-freezing condition is that |Tpc-T1|≤n1 for a second preset time duration t2; If the third anti-freezing condition is satisfied, the air conditioner is controlled to enter the anti-freezing protection mode.

6. The anti-freezing control method of an air conditioner according to claim 5, characterized by, It is further determined whether an anti-freezing exit condition is satisfied; if yes, the anti-freezing protection is exited; if not, the anti-freezing protection mode is returned to; The anti-freezing exit condition is that when the air conditioner enters the anti-freezing protection mode, the exhaust temperature Tpf at the time of entering the anti-freezing protection is recorded; if the exhaust temperature variation rate ΔTpc / Δt≥k3 or Tpf-Tpc≤n2 for a third preset time duration t3.

7. The anti-freezing control method of an air conditioner according to claim 5, said air conditioner including a compressor, characterized by, In the anti-freezing protection mode, the compressor is operated at a preset frequency or the compressor is stopped.

8. An air conditioner characterized by comprising: The anti-freezing control device of the air conditioner according to any one of claims 1 to 4.

9. A computer-readable storage medium, characterized in that, The anti-freezing control method of the air conditioner according to any one of claims 5 to 7.

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