A defrosting method of a double-condenser multi-connected air conditioner and air conditioner

Abstract

The application provides a defrosting method for a double-condenser multi-connected system, which comprises the following steps: S1: in a first defrosting mode, setting the opening degree Pn1 of a first electronic expansion valve and the opening degree Pn2 of a second electronic expansion valve according to a current increment difference ΔI; S4: when the defrosting temperature sensing bulb temperature of at least one condenser does not meet a defrosting exit condition, continuously adjusting the opening degree of the electronic expansion valve corresponding to the condenser until the defrosting temperature sensing bulb temperature Tdef1 of the first condenser and the defrosting temperature sensing bulb temperature Tdef2 of the second condenser both meet the defrosting exit condition, and the second defrosting mode is exited. Whether the system enters the second defrosting mode in the first defrosting mode is judged by the pressure in the system, and in the second defrosting mode, when the defrosting temperature sensing bulb temperature of at least one condenser does not meet the defrosting exit condition, the opening degree of the electronic expansion valve corresponding to the defrosting temperature sensing bulb temperature which does not meet the defrosting exit condition is continuously adjusted, so that the two condensers can exit the defrosting condition synchronously.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of air conditioner defrosting technology, in particular, relates to a defrosting method of a double-condenser multi-split air conditioner and an air conditioner. BACKGROUND

[0002] At present, the capacity of the multi-split heat pump outdoor unit developed in the market is becoming larger and larger, and the trend is that part of the large-capacity outdoor units are double-condenser structures. During actual heating operation, due to different positions of the two condensers, different internal space structures of the outdoor unit, and different refrigerant distribution deviations, the frost amount and frost distribution are inconsistent.

[0003] At present, the air conditioner usually adopts hot gas defrosting (after entering the defrosting mode, it needs to be stopped and converted to operate in the refrigeration mode, and the frost on the surface of the outdoor heat exchanger is removed by the high-temperature compressor discharge gas) to defrost. When the multi-split air conditioner with a double-condenser structure defrosts, the defrosting progress of the two condensers is often out of sync: one condenser has been defrosted completely, and the other condenser has not completed defrosting. This results in a long overall defrosting cycle of the outdoor unit and poor user experience.

[0004] At present, the control method is as follows: when the defrosting temperature sensor temperature Tdef of the two condensers reaches the exit condition, the defrosting mode is exited, and the defrosting is completed (the exit condition of hot gas defrosting: the defrosting temperature sensor temperature Tdef is greater than or equal to 8 DEG C for 2 minutes, or the defrosting temperature sensor temperature Tdef is greater than or equal to 11 DEG C, and the defrosting time is greater than or equal to 5 minutes, then the system exits the defrosting mode).

[0005] As a result, the condenser that has been defrosted completely does not exit the defrosting mode due to the need to wait for the other condenser to complete defrosting, resulting in low defrosting efficiency and low defrosting effect, and poor customer experience.

[0006] Based on this, the present application proposes a defrosting method of a double-condenser multi-split air conditioner to solve the above technical problems. SUMMARY

[0007] The present application solves the problem that the defrosting progress of the two condensers is often different, resulting in different defrosting progress of the two condensers, low defrosting efficiency, and poor customer experience.

[0008] To solve the above problems, the application provides a defrosting method of a double-condenser multi-connected system, comprising the following steps: S1: in a first defrosting mode, setting the opening degree Pn1 of a first electronic expansion valve and the opening degree Pn2 of a second electronic expansion valve according to a current increment difference ΔI; S2: every time interval, judging whether the system enters a second defrosting mode through system pressure; S3: after entering the second defrosting mode, judging the defrosting temperature sensing bulb temperature Tdef1 of the first condenser and the defrosting temperature sensing bulb temperature Tdef2 of the second condenser, and judging whether each satisfies a defrosting exit condition; S4: when the defrosting temperature sensing bulb temperature of at least one condenser does not satisfy the defrosting exit condition, continuously adjusting the opening degree of the electronic expansion valve corresponding to the condenser until the defrosting temperature sensing bulb temperature Tdef1 of the first condenser and the defrosting temperature sensing bulb temperature Tdef2 of the second condenser both satisfy the defrosting exit condition, and exiting the second defrosting mode.

[0009] Compared with the prior art, the technical effects achieved by the scheme are as follows: whether the system enters the second defrosting mode in the first defrosting mode is judged through the pressure in the system, and in the second defrosting mode, whether each satisfies the defrosting exit condition is judged through the defrosting temperature sensing bulb temperature of the condenser, and when the defrosting temperature sensing bulb temperature of at least one condenser does not satisfy the defrosting exit condition, the opening degree of the electronic expansion valve corresponding to the condenser that does not satisfy the defrosting exit condition is continuously adjusted, so that the two condensers both satisfy the defrosting exit condition, and the two condensers can exit the defrosting condition in a process close to synchronization.

[0010] In the embodiment, the method further comprises adjusting a defrosting method, specifically comprising the following steps: S100: in a heating mode, every time interval, detecting and recording the defrosting temperature sensing bulb temperature Tdef1 of the first condenser and the defrosting temperature sensing bulb temperature Tdef2 of the second condenser, and calculating the temperature difference ΔT=Tdef1-Tdef2; adjusting the rotation speed of the fan corresponding to the defrosting temperature sensing bulb temperature that is relatively low; S200: every time interval, detecting the current of the first fan and the second fan, and if the current of the first fan and the second fan is greater than a preset value, or the fan adjustment time in the above S100 exceeds a preset value, the rotation speed of the first fan and the second fan is restored to an initial value.

[0011] The technical effects after adopting the technical scheme are as follows: in order to slow down the frosting rate of the condenser on the fast-frosting side, the rotation speed of the corresponding external fan is adjusted, which helps the two condensers to exit the defrosting condition in synchronization, and guarantees the experience of the user; and the reliability of the external fan is also taken into account, and when the current of the external fan exceeds a threshold value or the rotation speed adjustment of the external fan exceeds a certain time, the rotation speed of the external fan is restored to an initial position, so that the load overload caused by the continuous operation of the external fan due to continuous frosting is prevented, and the reliability is affected.

[0012] In the embodiment, the fan rotating speed corresponding to the relatively low defrosting temperature of the defrosting temperature sensing bulb of the first condenser W 风机 = W 0风机 +f, f is determined according to the following conditions: △T≤1℃, f=0; 1℃<△T<3℃, f=60; △T≥3℃, f=120.

[0013] The technical effect after adopting the technical scheme is that the rotating speed adjustment amount of the fan is determined by the temperature difference between the defrosting temperature sensing bulb Tdef1 of the first condenser and the defrosting temperature sensing bulb Tdef2 of the second condenser, so that the stepwise rotating speed adjustment is realized, and the adjustment is more accurate.

[0014] In the embodiment, the current increment difference △I includes: the current increment difference △I = △I 风机2 - △I 风机1； , wherein the first fan current increment △I 风机1 = I 风机1除霜前 - I 风机1结霜前 ; the second fan current increment △I 风机2 = I 风机2除霜前 -I 风机2结霜前 .

[0015] The technical effect after adopting the technical scheme is that the current increment difference is obtained by the difference between the first fan current increment and the second fan current increment, and the first fan current increment and the second fan current increment are obtained by the difference between the current before defrosting and the current before frosting, so that the current increment difference is accurately obtained, and the initial opening of the electronic expansion valve is laid a foundation.

[0016] In the embodiment, setting the opening Pn1 of the first electronic expansion valve and the opening Pn2 of the second electronic expansion valve according to the current increment difference △I includes: comparing the value of △I, when △I≤0.2A, setting the opening Pn1 of the first electronic expansion valve and the opening Pn2 of the second electronic expansion valve to be equal; when 0.2A<△I<0.5A, setting the opening Pn1 of the first electronic expansion valve to be C and the opening Pn2 of the second electronic expansion valve to be D, and D-C=K, wherein K is a constant; when △I≥0.5A, setting the opening Pn1 of the first electronic expansion valve to be the minimum opening and the opening Pn2 of the second electronic expansion valve to be the maximum opening.

[0017] The technical effect after adopting the technical scheme is that the opening Pn1 of the first electronic expansion valve and the opening Pn2 of the second electronic expansion valve are set by the current increment difference, and the opening Pn1 of the first electronic expansion valve and the opening Pn2 of the second electronic expansion valve are set in steps according to the range of the current increment difference, so that the initial opening of the first electronic expansion valve and the second electronic expansion valve is more accurate.

[0018] In the embodiment, the condition for entering the first defrosting mode includes that any one of the condensers Tdef1 or Tdef2 is detected to be less than a set threshold temperature in the heating operation mode.

[0019] The technical effect after the technical scheme is adopted is that any one of the condensers is detected to be less than a threshold temperature in the heating operation mode, and the general threshold temperature is set to be -12℃, which indicates that frost gradually increases and needs to enter the first defrosting mode for defrosting.

[0020] In the embodiment, the defrosting exit condition includes that any one of the condensers Tdef1 or Tdef2 is Tdef≥ 8℃ for 2 minutes or Tdef≥ 11℃.

[0021] The technical effect after the technical scheme is adopted is that the condensers are kept at a certain temperature for a period of time or kept outside a specific temperature, so that the condensers complete the defrosting operation and ensure the user experience.

[0022] In the embodiment, the continuous adjustment of the opening degree of the electronic expansion valve corresponding to the condenser includes that the opening degree Pn1 of the first electronic expansion valve is Pn1=Pn01-a, and the opening degree Pn2 of the second electronic expansion valve is Pn2=Pn02+a, wherein the value of a is related to the temperature difference between the first condenser defrosting temperature sensor Tdef1 and the second condenser defrosting temperature sensor Tdef2.

[0023] The technical effect after the technical scheme is adopted is that the opening degrees of the first electronic expansion valve and the second electronic expansion valve are adjusted by a, and the value of a is related to the temperature difference between the first condenser defrosting temperature sensor Tdef1 and the second condenser defrosting temperature sensor Tdef2, so as to ensure accurate adjustment and control of the opening degrees of the first electronic expansion valve and the second electronic expansion valve and ensure that the two condensers can exit the defrosting operation synchronously.

[0024] In the embodiment, when Tdef1-Tdef2≤2℃, a=0; when 2℃

[0025] The technical effect after the technical scheme is adopted is that the opening degrees of the first electronic expansion valve and the second electronic expansion valve are adjusted by a, and the value of a is related to the temperature difference between the first condenser defrosting temperature sensor Tdef1 and the second condenser defrosting temperature sensor Tdef2, so as to ensure accurate adjustment and control of the opening degrees of the first electronic expansion valve and the second electronic expansion valve and ensure that the two condensers can exit the defrosting operation synchronously.

[0026] The embodiment also provides an air conditioner for executing a defrosting method of a double-condenser multi-connected system, which comprises an outdoor unit, the outdoor unit comprising a first fan, a second fan, a first condenser, a second condenser, and a first electronic expansion valve and a second electronic expansion valve.

[0027] The technical effects of any of the above embodiments can be achieved, and will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 A structure schematic diagram of a dual-condenser multi-connected system of the present application;

[0029] Figure 2 A schematic diagram of a defrosting process in the present application. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0031] The present embodiment also provides a defrosting method of a dual-condenser multi-connected system, as shown in Figure 1 、 2 S1: in the first defrosting mode, setting the opening degree Pn1 of the first electronic expansion valve and the opening degree Pn2 of the second electronic expansion valve according to the current increment difference ΔI; S2: every time interval, judging whether the system enters the second defrosting mode through the system pressure; S3: after entering the second defrosting mode, judging the defrosting temperature-sensing bulb temperature Tdef1 of the first condenser and the defrosting temperature-sensing bulb temperature Tdef2 of the second condenser, and judging whether each satisfies the defrosting exit condition; S4: when the defrosting temperature-sensing bulb temperature of at least one condenser does not satisfy the defrosting exit condition, continuously adjusting the opening degree of the electronic expansion valve corresponding to the condenser until the defrosting temperature-sensing bulb temperature Tdef1 of the first condenser and the defrosting temperature-sensing bulb temperature Tdef2 of the second condenser both satisfy the defrosting exit condition, and exiting the second defrosting mode.

[0032] The air conditioner outdoor unit normally operates in the heating mode, and when the defrosting temperature-sensing bulb temperature Tdef1 or Tdef1 of any condenser is detected to be less than a set threshold value during the heating operation process, generally set as -12℃, it indicates that the frost on the surface of the condenser has affected the normal operation of the outdoor unit, and the first defrosting mode needs to be entered to ensure the user experience. In order to determine whether the frost has been completely removed, it is necessary to determine whether the second defrosting mode has been entered, and the present application detects the high pressure of the system, and the judgment condition uses Pd n+1 -Pd n > C, and generally as preferred, C is 0.25 bar, wherein Pd n+1 is the detected high pressure at this time, and Pd nThe high pressure pressure at the last detection, since the detection system high pressure pressure is every certain time, preferably 20s interval, the detection result can be recorded in the controller, and stored according to the storage capacity of the controller, the stored data at least includes the system high pressure pressure of the last 5 groups, to ensure the accuracy of the detection into the second defrosting mode. The reason for using high pressure pressure to judge whether to enter the second defrosting mode is that when the frost is thin, the high pressure saturation temperature is increased, and the overall heat exchange effect of the condenser is good, and the high pressure saturation temperature and the high pressure pressure are one-to-one corresponding.

[0033] The defrosting temperature sensing bag temperature Tdef1 of the first condenser and the defrosting temperature sensing bag temperature Tdef2 of the second condenser can more accurately reflect the defrosting degree and judge whether the defrosting is clean.

[0034] If Tdef1 and Tdef2 both satisfy the defrosting exit condition (Tdef≥ 8℃ for 2min, or Tdef≥ 11℃), the first electronic expansion valve and the second electronic expansion valve opening degree Pn1, Pn2 remain unchanged until the defrosting shortest time 5min (the time is calculated from entering defrosting, that is, the four-way valve reversing) is satisfied, since the defrosting has a minimum time, preferably 5min, at this time the first condenser and the second condenser can be synchronized to exit the second defrosting mode.

[0035] If Tdef1 satisfies the defrosting exit condition and Tdef2 does not satisfy, the opening degree Pn1 of the first electronic expansion valve is adjusted to the minimum value A (generally 100pls), and the opening degree Pn2 of the second electronic expansion valve is adjusted to the maximum value B (generally 480pls). Since the minimum opening degree and the maximum opening degree of the electronic expansion valve are limited, such as the minimum opening degree is generally 100pls, and the maximum opening degree is generally 480pls, by adjusting the opening degree of the electronic expansion valve, the refrigerant amount in the two condensers is adjusted, so that the two condensers can be synchronized to exit the second defrosting mode. Conversely, if Tdef2 satisfies the defrosting exit condition and Tdef1 does not satisfy, then the first electronic expansion valve opening degree is adjusted to the maximum value, and the second electronic expansion valve opening degree is adjusted to the minimum value.

[0036] If Tdef1 and Tdef2 do not satisfy the defrosting exit condition, Tdef1 and Tdef2 are detected every certain time (generally 20s), the electronic expansion valve opening degree is continuously adjusted, the first electronic expansion valve opening degree Pn1=Pn01-a, and the second electronic expansion valve opening degree Pn2=Pn02+a. Until the defrosting is finished, and the second defrosting mode is exited. Thus, the refrigerant amount in the two condensers is adjusted, so that the two condensers can be synchronized to exit the second defrosting mode.

[0037] Further, the method for adjusting defrosting further comprises the following steps: S100: in the heating mode, every time interval, detecting and recording the temperature of the defrosting temperature sensor of the first condenser Tdef1 and the temperature of the defrosting temperature sensor of the second condenser Tdef2, and calculating the temperature difference AT = Tdef1-Tdef2; adjusting the rotating speed of the fan corresponding to the lower temperature of the defrosting temperature sensor; S200: every time interval, detecting the current of the first fan and the second fan, if the current of the first fan and the second fan is greater than a preset value, or the time of the fan adjustment in the above S100 exceeds the preset value, the rotating speed of the first fan and the second fan returns to the initial value.

[0038] The present application has disclosed that in the case of uneven frosting of the two condensers, the opening of the first electronic expansion valve and the opening of the second electronic expansion valve are adjusted to realize the synchronization of the two condensers in the defrosting mode. In order to reduce the phenomenon from the root, the present application also provides a method for slowing down the frosting. Since the frosting degree of the two condensers is different, for the convenience of description, it is assumed that the second condenser frosts fast and defrosts slowly. Then, when the temperature difference between the defrosting temperature sensor of the first condenser Tdef1 and the defrosting temperature sensor of the second condenser Tdef2 is detected, AT is positive, and accordingly the rotating speed of the outer fan (the second fan) corresponding to the second condenser is adjusted, so that the frosting degree of the two condensers is consistent, thereby keeping the subsequent defrosting procedure consistent.

[0039] On the contrary, when the first condenser frosts fast and defrosts slowly, AT is negative, and accordingly the rotating speed of the outer fan (the first fan) corresponding to the first condenser is adjusted.

[0040] Further, adjusting the rotating speed of the fan corresponding to the lower temperature of the defrosting temperature sensor comprises W 风机 = W 0风机 +f, f is valued according to the following conditions: AT ≤1℃, f=0; 1℃<AT<3℃, f=60; AT≥3℃, f=120.

[0041] According to the condition of AT, the rotating speed of the fan is adjusted. When AT≤1℃, it indicates that the temperature difference is not very large, at this time the rotating speed of the second fan does not need to be adjusted, only the original rotating speed needs to be maintained. When 1℃<AT<3℃, it indicates that the second condenser is low in temperature and has more frost, so the rotating speed of the fan needs to be increased to strengthen the heat exchange of the second condenser and slow down the frosting speed of the second condenser. When T≥3℃, compared with the state of 1℃<AT<3℃, the second condenser is more serious in temperature and frost, so the rotating speed of the fan needs to be increased. Accordingly, the rotating speed of the fan is changed by the value of AT, to achieve the effect of adjustment. Wherein, W 风机 The rotating speed of the fan after adjustment, and W 0风机The fan speed before the speed is not adjusted.

[0042] Further, the current increment difference △I includes: the current increment difference △I=△I 风机2 - △I 风机1； Wherein, the first fan current increment △I 风机1 = I 风机1除霜前 - I 风机1结霜前 ; the second fan current increment △I 风机2 = I 风机2除霜前 - I 风机2结霜前 .

[0043] The current increments of the first fan and the second fan caused by frosting are △I 风机1 and △I 风机2 , and wherein, △I 风机1 = I 风机1除霜前 - I 风机1结霜前 ; △I 风机2 = I 风机2除霜前 - I 风机2结霜前 , wherein the current when the heating is stably running for 10 minutes is the current I 结霜前 before frosting (it is considered that there is no frost at this time), and the last recorded current before entering the defrosting mode is the current I 除霜前 before defrosting (it is considered that the frost is the most at this time).

[0044] Further, setting the opening degree Pn1 of the first electronic expansion valve and the opening degree Pn2 of the second electronic expansion valve according to the current increment difference △I includes: comparing the value of △I, when △I≤0.2A, setting the opening degree Pn1 of the first electronic expansion valve and the opening degree Pn2 of the second electronic expansion valve to be equal; when 0.2A<△I<0.5A, setting the opening degree Pn1 of the first electronic expansion valve to be C and the opening degree Pn2 of the second electronic expansion valve to be D, and D-C=K, wherein K is a constant; when △I≥0.5A, setting the opening degree Pn1 of the first electronic expansion valve to be the minimum opening degree and the opening degree Pn2 of the second electronic expansion valve to be the maximum opening degree.

[0045] According to △I, the initial opening degree Pn1 of the first electronic expansion valve and the initial opening degree Pn2 of the second electronic expansion valve are set and the defrosting is started (the conventional reversing defrosting, at this time, the first fan and the second fan stop rotating and there is no current, therefore the current mentioned above is the current detected during heating), Pn1 and Pn2 are directly adjusted to the initial opening degree after reversing, that is, at stage 1, the valve is always operated according to the initial opening degree, and the details are as follows: Figure 2

[0046] ​When ΔI≤0.2A, the opening degree Pn1 of the first electronic expansion valve and the opening degree Pn2 of the second electronic expansion valve are set to be equal, preferably Pn1=Pn2=300 pls; when 0.2A<ΔI<0.5A, the opening degree Pn1 of the first electronic expansion valve is set to be C, preferably Pn1=200 pls, the opening degree Pn2 of the second electronic expansion valve is set to be D, preferably Pn2=400 pls, and D-C=K, wherein K is a constant, and the corresponding K=200 pls; when ΔI≥0.5A, the opening degree Pn1 of the first electronic expansion valve is set to be the minimum opening degree, and the opening degree Pn2 of the second electronic expansion valve is set to be the maximum opening degree, preferably Pn1=100 pls, and preferably Pn2=480 pls. The above embodiments are described under the assumption that the second condenser frosts quickly and defrosts slowly. If the first condenser frosts quickly and defrosts slowly, the opening degree Pn1 of the first electronic expansion valve and the opening degree Pn2 of the second electronic expansion valve are set to be opposite.

[0047] Further, the condition for entering the first defrosting mode includes detecting that any one of the condensers Tdef1 or Tdef2 < a set threshold temperature in the heating operation mode.

[0048] Detecting that any one of the condensers is less than a threshold temperature in the heating operation mode, and the general threshold temperature is set to be -12℃, indicating that frost is gradually increasing, and the first defrosting mode needs to be entered for defrosting.

[0049] Further, the defrosting exit condition includes that any one of the condensers Tdef1 or Tdef2, Tdef≥ 8℃ for 2 min, or Tdef≥ 11℃.

[0050] The condenser is kept at a certain temperature for a period of time or kept outside a certain temperature, so that the condenser completes the defrosting operation and ensures the user experience.

[0051] Further, the continuous adjustment of the opening degree of the electronic expansion valve corresponding to the condenser includes that the opening degree Pn1 of the first electronic expansion valve is Pn01-a, and the opening degree Pn2 of the second electronic expansion valve is Pn02+a; wherein the value of a is related to the temperature difference between the defrosting temperature sensing bulb temperature Tdef1 of the first condenser and the defrosting temperature sensing bulb temperature Tdef2 of the second condenser.

[0052] The opening degree of the first electronic expansion valve and the second electronic expansion valve is adjusted by adding or subtracting a, and the value of a is related to the temperature difference between the defrosting temperature sensing bulb temperature Tdef1 of the first condenser and the defrosting temperature sensing bulb temperature Tdef2 of the second condenser, so as to ensure accurate adjustment and control of the opening degree of the first electronic expansion valve and the second electronic expansion valve, and ensure that the two condensers can exit the defrosting operation synchronously. Wherein, Pn1 and Pn2 represent the opening degree of the first electronic expansion valve and the second electronic expansion valve after adjustment; Pn01 and Pn02 represent the opening degree of the first electronic expansion valve and the second electronic expansion valve before adjustment.

[0053] Further, when Tdef1-Tdef2≤2℃, a=0; when 2℃

[0054] The opening degree of the first electronic expansion valve and the second electronic expansion valve is adjusted by adding or subtracting a, and the value of a is related to the temperature difference between the defrosting temperature sensing bulb temperature Tdef1 of the first condenser and the defrosting temperature sensing bulb temperature Tdef2 of the second condenser, so as to ensure accurate adjustment and control of the opening degree of the first electronic expansion valve and the second electronic expansion valve, and ensure that the two condensers can exit the defrosting operation synchronously. Wherein a=0, 5, 15, and the unit is pls.

[0055] The application also provides an air conditioner for executing the defrosting method of the double-condenser multi-connected system, which comprises an outdoor unit, the outdoor unit comprising a first fan, a second fan, a first condenser, a second condenser, and a first electronic expansion valve and a second electronic expansion valve.

[0056] Although the application is disclosed as above, the application is not limited to this. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the application, and the protection scope of the application should be limited by the scope defined in the claims.

Claims

1. A defrosting method of a dual-condenser multi-connected system, comprising the following steps: characterized in that, S1: in a first defrosting mode, setting the opening degree Pn1 of a first electronic expansion valve and the opening degree Pn2 of a second electronic expansion valve according to a current increment difference △I; S2: every time interval, determining whether the system enters a second defrosting mode by system pressure; S3: after entering the second defrosting mode, determining the defrosting temperature sensor temperature Tdef1 of the first condenser and the defrosting temperature sensor temperature Tdef2 of the second condenser, and determining whether each satisfies a defrosting exit condition; S4: when the defrosting temperature sensor temperature of at least one condenser does not satisfy the defrosting exit condition, continuously adjusting the opening degree of the electronic expansion valve corresponding to the condenser until the defrosting temperature sensor temperature Tdef1 of the first condenser and the defrosting temperature sensor temperature Tdef2 of the second condenser both satisfy the defrosting exit condition, and exiting the second defrosting mode; the current increment difference △I comprises: The current increment difference ΔI = ΔI 风机2 - ΔI 风机1； Wherein, the first fan current increment AI 风机1 = I 风机1除霜前 - I 风机1结霜前 ; the second fan current increment AI 风机2 = I 风机2除霜前 - I 风机2结霜前 .

2. The defrosting method of a dual-condenser multi-connected system according to claim 1, wherein, The method further comprises adjusting a frosting method, specifically comprising the following steps: S100: in a heating mode, every time interval, detecting and recording the defrosting temperature sensor temperature Tdef1 of the first condenser and the defrosting temperature sensor temperature Tdef2 of the second condenser, and calculating the temperature difference △T = Tdef1-Tdef2; adjusting the fan speed corresponding to the defrosting temperature sensor temperature that is relatively lower; S200: every time interval, detecting the current of the first fan and the second fan, and if the current of the first fan and the second fan is greater than a preset value, or the fan adjustment time in the above S100 exceeds a preset value, the fan speed of the first fan and the second fan returns to the initial value. 3.The defrosting method of a dual-condenser multi-connected system according to claim 2, wherein, The fan rotating speed corresponding to the relatively low temperature of the frost adjusting temperature sensing bulb includes W 风机 = W 0风机 +f, f is valued according to the following conditions: △T≤1℃, f=0; 1℃<△T<3℃, f=60; △T≥3℃, f=120. 4.The defrosting method of a dual-condenser multi-connected system according to claim 1, wherein, Setting the opening degree Pn1 of the first electronic expansion valve and the opening degree Pn2 of the second electronic expansion valve according to the current increment difference △I comprises: comparing the value of △I, when △I≤0.2A, setting the opening degree Pn1 of the first electronic expansion valve and the opening degree Pn2 of the second electronic expansion valve to be equal; when 0.2A<△I<0.5A, setting the opening degree Pn1 of the first electronic expansion valve to be C, and the opening degree Pn2 of the second electronic expansion valve to be D, and D-C=K, wherein K is a constant; when △I≥0.5A, setting the opening degree Pn1 of the first electronic expansion valve to be the minimum opening degree, and the opening degree Pn2 of the second electronic expansion valve to be the maximum opening degree. 5.The defrosting method of a double-condenser multi-connected system according to claim 1, wherein, The condition for entering the first defrosting mode comprises: detecting that any one of the condenser Tdef1 or Tdef2 is less than a set threshold temperature in a heating operation mode. 6.The defrosting method of a dual-condenser multi-connected system according to claim 1, wherein, The defrosting exit condition comprises that any one of the condenser Tdef1 or Tdef2 is Tdef≥8℃ for 2 minutes, or Tdef≥11℃. 7.The defrosting method of a dual-condenser multi-connected system according to claim 1, wherein, The continuously adjusting the opening degree of the electronic expansion valve corresponding to the condenser comprises: the opening degree Pn1 of the first electronic expansion valve = Pn01-a; the opening degree Pn2 of the second electronic expansion valve = Pn02+a; wherein the value of a is related to the temperature difference between the defrosting temperature sensor temperature Tdef1 of the first condenser and the defrosting temperature sensor temperature Tdef2 of the second condenser. 8.The defrosting method of a double-condenser multi-connected system according to claim 7, wherein, When the Tdef1-Tdef2≤2℃, the a=0; when 2℃ 9. An air conditioner characterized by comprising: A defrosting method for performing a double-condenser multi-connected system as claimed in any one of claims 1-8, Comprises: An outdoor unit, The outdoor unit comprises a first fan, a second fan, a first condenser, a second condenser, and a first electronic expansion valve and a second electronic expansion valve.

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