Control method, controller and air conditioner for defrosting of air conditioner

Abstract

The present invention relates to a control method, controller and air conditioner for defrosting an air conditioner. By monitoring the changing pattern of the outdoor coil temperature after defrosting the air conditioner, and predicting the time when the defrost will arrive based on the changing pattern, the time when the chassis heater is turned on in advance of a preset time is finally determined based on the time when the defrost will arrive. Compared with the prior art method of controlling the chassis heater to turn on based on the outdoor coil temperature, the air conditioner of the present invention controls the chassis heater to turn on in advance before the next defrost based on the changing pattern of the outdoor coil temperature after defrosting, which can effectively achieve early preheating of the chassis, and the first preset time for the early start is determined based on the changing pattern of the outdoor coil temperature before defrosting, and is not fixed, thereby further effectively achieving the preheating process of the chassis, thereby effectively preventing the problem of condensed water on the chassis freezing and clogging the water outlet during the defrosting process.

Description

Technical Field

[0001] The invention relates to a control method, a controller and an air conditioner for defrosting an air conditioner, and belongs to the application field of air conditioner control technology. Background Art

[0002] During the air conditioner's heating process, the outdoor condenser is prone to frost. To ensure the air conditioner's heating performance, the outdoor unit of the air conditioner undergoes regular defrosting to melt the frost on the condenser surface. During the defrosting process, a large amount of condensed water drips onto the chassis and forms ice on the chassis, which blocks the water outlet and affects the normal water flow from the chassis outlet. To solve this problem, an electric heater is installed on the air conditioner chassis to heat the chassis during defrosting and prevent it from freezing. Currently, the chassis heater is turned on based on the temperature of the outdoor condenser coil, or it is controlled to turn on only during the defrosting process. This control method sometimes makes it difficult to fully heat the chassis during the defrosting process, and the problem of ice blocking the water outlet still occurs, preventing the chassis from draining effectively. Summary of the Invention

[0003] The present invention aims to solve the problem that the chassis of the existing air conditioner still freezes and blocks the water outlet due to the untimely operation of the chassis heater, and proposes an improved control method.

[0004] Specifically, the present invention discloses a control method for defrosting an air conditioner, the control method comprising:

[0005] Monitor the changing pattern of outdoor coil temperature after defrosting of air conditioner;

[0006] Predict the time of defrost arrival based on the changing rules;

[0007] The time for the chassis heater to be turned on in advance of the preset time is determined based on the arrival time of this defrost.

[0008] Optionally, monitoring the change pattern of the outdoor coil temperature after defrosting the air conditioner includes:

[0009] The time for the outdoor coil temperature of the air conditioner to drop to the first preset temperature after two consecutive defrosting operations is monitored to determine the changing pattern.

[0010] Optionally, predicting the time of defrost arrival based on the change rule includes:

[0011] Get the time when the last defrost arrived;

[0012] The time for this defrost to arrive is determined based on the changing pattern and the time when the previous defrost was turned on.

[0013] Optionally, the control method further includes:

[0014] Get the outdoor coil temperature when the air conditioner starts heating after two consecutive defrosts;

[0015] The variation rule is determined based on the time taken for the outdoor coil temperature to drop to the first preset temperature after two consecutive defrosting operations and the two monitored outdoor coil temperatures.

[0016] Optionally, the control method further includes:

[0017] When the second preset time after defrosting is completed arrives, the chassis heater is controlled to be turned off.

[0018] Optionally, the control method further includes:

[0019] Obtain the defrost time of the air conditioner, and correct the second preset time according to the defrost time.

[0020] The present invention also proposes a controller for an air conditioner, which is configured to: monitor the changing pattern of the outdoor coil temperature after the air conditioner defrosts, predict the time when the defrost will arrive based on the changing pattern, and determine the time to turn on the chassis heater in advance of a preset time based on the time when the defrost will arrive.

[0021] Optionally, when monitoring the changing pattern of the outdoor coil temperature after defrosting of the air conditioner, the controller is further configured to: monitor the time it takes for the outdoor coil temperature to drop to a first preset temperature after two consecutive defrosting of the air conditioner to determine the changing pattern.

[0022] Optionally, when predicting the time of arrival of this defrost according to the changing rules, the controller is further configured to: obtain the time of arrival of the previous defrost; and determine the time of arrival of this defrost according to the changing rules and the time when the previous defrost was turned on.

[0023] The present invention also provides an air conditioner, in which the controller of the air conditioner is arranged.

[0024] The control method for defrosting an air conditioner of the present invention monitors the changing pattern of the outdoor coil temperature after defrosting the air conditioner, predicts the time when the defrost will arrive based on the changing pattern, and finally determines the time when the chassis heater is turned on in advance of a preset time based on the time when the defrost will arrive. Compared with the prior art method of controlling the chassis heater to turn on based on the outdoor coil temperature, or turning on the controller only during the defrost process, the control method of the present invention predicts the time when the defrost will arrive based on the changing pattern of the outdoor coil temperature after defrosting, thereby controlling the electric heater to be turned on in advance before the defrost, which can effectively achieve early preheating of the chassis. Moreover, the first preset time for the early start is determined based on the changing pattern of the outdoor coil temperature before defrosting, and is not fixed. Therefore, the time for the early start can be determined in combination with the specific heating state before defrosting, thereby further effectively achieving the preheating process of the chassis, thereby effectively preventing the condensed water on the chassis from freezing during the defrost process, and thus completely solving the problem of blocked water outlets. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Flowchart of a control method for defrosting an air conditioner according to an embodiment of the present invention;

[0026] Figure 2 A curve showing the change in temperature of the outdoor coil of the air conditioner over time from the time of reheating after defrosting to the time of defrosting again in the control method of an embodiment of the present invention;

[0027] Figure 3 A flow chart of a control method for defrosting an air conditioner according to another embodiment of the present invention;

[0028] Figure 4 The present invention is a flowchart of a control method for defrosting an air conditioner according to another embodiment of the present invention. DETAILED DESCRIPTION

[0029] The following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0030] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0031] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features specified as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0032] The present invention proposes a control method for defrosting an air conditioner. Figure 1 As shown, the control method includes the following steps:

[0033] S100, monitoring the changing pattern of the outdoor coil temperature after defrosting of the air conditioner;

[0034] S200, predicting the time when the defrost will arrive based on the change pattern;

[0035] S300: Determine the time for the chassis heater to be turned on in advance of the preset time according to the current defrost arrival time.

[0036] In step S100, during the defrost process, the indoor evaporator is in cooling mode while the outdoor condenser is in heating mode. This is contrary to the normal heating mode, where the evaporator heats and the condenser cools. Therefore, the outdoor condenser's outdoor coil temperature decreases during the defrost process. After defrosting, when heating resumes, the outdoor coil temperature gradually decreases again. This can be used to monitor the temperature drop, such as the rate of outdoor coil temperature drop over a period of time, to determine the temperature variation pattern.

[0037] In steps S200 and S300, after determining the temperature variation pattern, such as the rate of decrease in coil temperature mentioned in the previous step, the arrival time of defrost for this air conditioner is determined based on the rate of decrease. This time is the predicted arrival time for this defrost based on the variation pattern. The actual arrival of defrost is determined based on the conditions for defrost entry, and defrost will not begin until the conditions are met. There may be a small deviation between the actual arrival time and the predicted arrival time, such as a difference of less than 3 minutes. After determining the arrival time for this defrost, the chassis heater is turned on at a preset time in advance of this time. This controls the chassis heater to turn on at the preset time before defrost to preheat the outdoor unit's chassis.

[0038] Compared with the prior art which controls the chassis heater to turn on according to the outdoor coil temperature, or turns on the controller only during the defrosting process, the present invention predicts the arrival time of this defrosting according to the changing pattern of the outdoor coil temperature after defrosting, thereby controlling the electric heater to be turned on in advance before this defrosting, which can effectively realize the early preheating of the chassis, and the first preset time of the early start is determined according to the changing pattern of the outdoor coil temperature before defrosting, and is not fixed. Therefore, the time of early start can be determined in combination with the specific heating state before defrosting, thereby further effectively realizing the preheating process of the chassis, thereby effectively preventing the condensed water on the chassis from freezing during the defrosting process, thereby completely solving the problem of blocked water outlet.

[0039] Furthermore, in some embodiments of the present invention, the monitoring of the change pattern of the outdoor coil temperature after defrosting of the air conditioner mentioned in the above embodiment includes:

[0040] The time for the outdoor coil temperature of the air conditioner to drop to the first preset temperature after two consecutive defrosting operations is monitored to determine the changing pattern.

[0041] Specifically, Figure 2 As shown in the figure, the curve of the outdoor coil temperature TP changing with time from the time the air conditioner resumes heating after defrosting to the time it enters defrosting again next time. During the heating process, the outdoor coil temperature gradually decreases. The time required for the outdoor coil temperature to drop to the first preset temperature T1 (such as -1°C) from the zero moment when heating is turned on after defrosting is monitored, which is shown as ta in the figure. The time ta1 and ta2 taken from the start of heating to the drop to T1 after two consecutive defrosts can be monitored, thereby obtaining the ratio of the cooling rates before and after, that is, ta2 / ta1.

[0042] Furthermore, after obtaining the changing law of the rate ratio, as Figure 3 As shown, the time of defrosting arrival is predicted based on the changing rules, including:

[0043] S210, obtaining the time when the previous defrost was reached;

[0044] S220: Determine the time when this defrost is to be completed based on the change pattern and the time when the previous defrost was started.

[0045] like Figure 2As shown, the time when the previous defrost was reached is tc1. After the previous defrost is completed, the interval time from the moment ta1 when the outdoor coil temperature drops to the first preset temperature T1 to the arrival of the previous defrost is tc1-ta1. According to the ratio of the cooling rates of the outdoor coil temperatures after two consecutive defrosts, ta2 / ta1, it is easy to calculate that the interval time from the moment ta2 when the outdoor coil temperature drops to the first preset temperature T1 to the arrival of this defrost is tc2-ta2. Since the ratio of the two interval times is approximately the ratio of the cooling rates of the two times, (tc2-ta2) / (tc1-ta1)=ta2 / ta1 is obtained, thereby obtaining the predicted time tc2 of the arrival of this defrost. Then, by subtracting the preset time interval tpr from tc2, the time tb=tc2-tpr for the early start of the electric heater can be obtained.

[0046] like Figure 2 As shown, the chassis heater is turned on at tb before defrosting to preheat the chassis. When the time reaches tc, the air conditioner detects the defrosting action and starts to execute the defrosting function. During the defrosting period, the outdoor coil temperature T3 also changes from a continuous decrease before defrosting to a gradual increase. When defrosting is completed and heating begins, the outdoor coil temperature T3 changes to a gradual decrease again, and the cycle continues.

[0047] It's worth noting that during the air conditioner's first operation, the chassis heater's pre-defrost time tb is a built-in default parameter. This default parameter was determined experimentally during the air conditioner's development process to set a reasonable time for the chassis heater to turn on by default before the air conditioner enters the heating and defrosting mode. Before the defrost cycle, the system monitors the time ta1 required for the outdoor coil temperature to drop to T1, as well as the previous defrost arrival time tc1. Before the next defrost cycle, the air conditioner monitors the time ta2 required for the outdoor coil temperature to drop to T1, and uses this to estimate the current defrost arrival time tc2. The chassis heater's turn-on time tb is then calculated based on this current defrost arrival time tc2. The chassis heater's turn-on time before each subsequent defrost cycle is determined based on the outdoor coil temperature's pre-defrost variation. This ensures that each subsequent chassis heater turn-on time is not fixed but adjusted in real time, ensuring the accuracy of the chassis heater's turn-on time.

[0048] In some embodiments of the present invention, Figure 4 As shown, the above control method also includes:

[0049] S410, obtaining the outdoor coil temperature when the air conditioner starts heating after two consecutive defrosts;

[0050] S510: Determine a variation pattern based on the monitored time for the outdoor coil temperature to drop to a first preset temperature after two consecutive defrosting operations and the two outdoor coil temperatures.

[0051] In the aforementioned control scheme, it is assumed that the outdoor coil temperature is approximately the same or very close to the temperature each time the air conditioner resumes heating after defrosting. Therefore, the cooling rate ratio between the two times is calculated as the ratio of the two consecutive cooling times, ta2 / ta1. In some actual air conditioner operating conditions, due to variations in outdoor ambient temperature or the length of defrost operation, the outdoor coil temperature at the start of heating after the two defrosts may differ significantly. In this case, the calculation of the cooling rate ratio between the two times needs to take this difference into account to obtain a relatively accurate result. The obtained outdoor coil temperatures at the start of heating after the two defrosts are Ts1 and Ts2. The cooling rate ratio between the two times is ((Ts2 - T1) / ta2) ÷ ((Ts1 - T1) / ta1), which represents the variation pattern of the outdoor coil temperature after defrosting.

[0052] In some embodiments of the present invention, the control method further includes: controlling the chassis heater to be turned off when a second preset time after defrosting is completed arrives.

[0053] In the above embodiment, the chassis heater is turned on before defrosting to preheat the chassis and remains on during the defrosting operation. After the defrosting is completed, in order to avoid the chassis heater being kept on and wasting the air conditioner's electricity, the chassis heater is controlled to be turned off after the defrosting is completed, after a second preset time is delayed, such as 10 minutes, to ensure that the frost on the chassis is completely melted, thereby saving electricity.

[0054] Furthermore, the control method further includes: obtaining a defrost time of the air conditioner, and correcting the second preset time according to the defrost time.

[0055] The conditions for exiting defrost vary depending on the degree of frost detected. The most significant difference lies in the defrost time. If the chassis heater is shut off with a constant delay, it may result in more frost during periods of long defrost times. If the chassis heater shuts off at the same second preset time, the frost in the chassis may not be fully melted, thus still posing a risk of clogging the chassis water outlet. Therefore, the second preset time needs to be adjusted based on the degree of frost. For long defrost times, the second preset time can be extended to, for example, 12 minutes; for short defrost times, it can be shortened to, for example, 8 minutes. This ensures that the chassis frost is fully melted while minimizing energy consumption.

[0056] The present invention also provides a controller for an air conditioner, which may include an indoor controller and an outdoor controller, connected by a communication line and respectively located in the indoor and outdoor units of the air conditioner. The outdoor controller is connected to an outdoor coil temperature sensor and an outdoor load such as a compressor. The indoor and outdoor controllers communicate, such as using a current loop, to mutually transmit air conditioner operating status information and control instructions. The indoor controller obtains outdoor coil temperature information and compressor operating information through communication, and determines whether the air conditioner is frosted based on the outdoor coil temperature and compressor operating status, thereby controlling the indoor unit load and controlling the outdoor unit load to enter a defrost state via the communication line. The controller further outputs a control instruction for controlling whether to activate the outdoor unit's chassis heater, which is transmitted to the outdoor controller via the communication line to control the operation of the chassis heater. Alternatively, the controller may be located only in the indoor unit of the air conditioner, with the outdoor unit's load control line and outdoor coil temperature sensor both connected to the indoor controller. The controller controls the air conditioner's defrost operation and the operating state of the chassis heater based on the outdoor coil temperature and compressor operating status.

[0057] Specifically, when controlling the operation of the outdoor chassis heater, the controller is configured to: monitor the change pattern of the outdoor coil temperature after the air conditioner defrosts, predict the time when this defrost will arrive based on the change pattern, and determine the time to turn on the chassis heater in advance of the preset time based on the time when this defrost will arrive.

[0058] During the defrost process, the indoor evaporator is cooling while the outdoor condenser is heating. This is the opposite of the normal heating mode, where the evaporator heats and the condenser cools. Therefore, the outdoor condenser's outdoor coil temperature decreases during the defrost process. After defrosting, when heating resumes, the outdoor coil temperature gradually decreases again. This can be used to monitor the outdoor coil temperature drop to determine temperature patterns, such as the rate of outdoor coil temperature drop over a period of time.

[0059] After determining the temperature variation pattern, such as the coil temperature drop rate mentioned in the previous step, the defrost arrival time for this air conditioner is determined based on the drop rate. This time is the predicted defrost arrival time based on the variation pattern. The actual defrost arrival time is determined based on the defrost entry conditions, and defrost will not begin until the conditions are met. There may be a small deviation between the actual defrost arrival time and the predicted defrost arrival time, such as a difference of within 3 minutes. After determining the defrost arrival time, the chassis heater activation time is determined based on this time and then advanced by a preset time. This control controls the chassis heater to activate a preset time in advance of defrost to preheat the outdoor unit's chassis.

[0060] Compared with the prior art which controls the chassis heater to turn on according to the outdoor coil temperature, or turns on the controller only during the defrosting process, the present invention predicts the arrival time of this defrosting according to the changing pattern of the outdoor coil temperature after defrosting, thereby controlling the electric heater to be turned on in advance before this defrosting, which can effectively realize the early preheating of the chassis, and the first preset time of the early start is determined according to the changing pattern of the outdoor coil temperature before defrosting, and is not fixed. Therefore, the time of early start can be determined in combination with the specific heating state before defrosting, thereby further effectively realizing the preheating process of the chassis, thereby effectively preventing the condensed water on the chassis from freezing during the defrosting process, thereby completely solving the problem of blocked water outlet.

[0061] Furthermore, in some embodiments of the present invention, when monitoring the changing pattern of the outdoor coil temperature after defrosting of the air conditioner mentioned in the above embodiments, the controller is also configured to: monitor the time it takes for the outdoor coil temperature to drop to a first preset temperature after two consecutive defrosts of the air conditioner to determine the changing pattern.

[0062] Specifically, Figure 2 The curve shown is a graph of the outdoor coil temperature changing with time from the time the air conditioner starts heating again after defrosting to the time it enters defrosting again. During the heating process, the outdoor coil temperature gradually decreases. The time required for the outdoor coil temperature to drop to the first preset temperature T1 (such as -1°C) from the zero moment when heating is turned on after defrosting is monitored, which is shown as ta in the figure. The time ta1 and ta2 taken from the start of heating to the drop to T1 after two consecutive defrosts are monitored, so that the ratio of the cooling rates before and after the two times, i.e., ta2 / ta1, can be obtained.

[0063] Furthermore, after obtaining the changing law of the rate ratio, when predicting the time of arrival of this defrost according to the changing law, the controller is also configured to: obtain the time of arrival of the previous defrost; determine the time of arrival of this defrost according to the changing law and the time when the previous defrost was turned on.

[0064] like Figure 2As shown, the time when the previous defrost was reached is tc1. After the previous defrost is completed, the interval time from the moment ta1 when the outdoor coil temperature drops to the first preset temperature T1 to the arrival of the previous defrost is tc1-ta1. According to the ratio of the cooling rates of the outdoor coil temperatures after two consecutive defrosts, ta2 / ta1, it is easy to calculate that the interval time from the moment ta2 when the outdoor coil temperature drops to the first preset temperature T1 to the arrival of this defrost is tc2-ta2. Since the ratio of the two interval times is approximately the ratio of the cooling rates of the two times, (tc2-ta2) / (tc1-ta1)=ta2 / ta1 is obtained, thereby obtaining the predicted time tc2 of the arrival of this defrost. Then, by subtracting the preset time interval tpr from tc2, the time tb=tc2-tpr for the early start of the electric heater can be obtained.

[0065] like Figure 2 As shown, the chassis heater is turned on at tb before defrosting to preheat the chassis. When the time reaches tc, the air conditioner detects the defrosting action and starts to execute the defrosting function. During the defrosting period, the outdoor coil temperature T3 also changes from a continuous decrease before defrosting to a gradual increase. When defrosting is completed and heating begins, the outdoor coil temperature T3 changes to a gradual decrease again, and the cycle continues.

[0066] It's worth noting that during the air conditioner's first operation, the chassis heater's pre-defrost time tb is a built-in default parameter. This default parameter was determined experimentally during the air conditioner's development process to set a reasonable time for the chassis heater to turn on by default before the air conditioner enters the heating and defrosting mode. Before the defrost cycle, the system monitors the time ta1 required for the outdoor coil temperature to drop to T1, as well as the previous defrost arrival time tc1. Before the next defrost cycle, the air conditioner monitors the time ta2 required for the outdoor coil temperature to drop to T1, and uses this to estimate the current defrost arrival time tc2. The chassis heater's turn-on time tb is then calculated based on this defrost arrival time tc2. The chassis heater's turn-on time before each subsequent defrost cycle is determined based on the outdoor coil temperature's pre-defrost pattern. This ensures that each subsequent chassis heater turn-on time is not fixed but adjusted in real time, ensuring the accuracy of the chassis heater's turn-on time.

[0067] In some embodiments of the present invention, the controller is further configured to: obtain the outdoor coil temperature when the air conditioner starts heating after two consecutive defrosting operations; and determine the change pattern based on the time it takes for the outdoor coil temperature to drop to the first preset temperature after two consecutive defrosting operations and the two outdoor coil temperatures.

[0068] In the control scheme implemented above, it is assumed that the outdoor coil temperature is roughly the same or has a small difference each time the air conditioner finishes defrosting and then resumes heating. Therefore, the cooling rate ratio between the two times is directly calculated as the ratio of the two consecutive cooling times, ta2 / ta1. In some actual air conditioner operating conditions, due to changes in outdoor ambient temperature or the length of working time during defrosting, the outdoor coil temperature may differ greatly when heating starts after the two defrosting ends. In this case, the cooling rate ratio between the two times needs to take into account the difference in outdoor coil temperature to obtain a relatively accurate calculation result. Figure 2 As shown in the figure, when the air conditioner starts heating after two defrosting operations, the outdoor coil temperatures are T01 and T02. The ratio of the cooling rates before and after the two operations is ((T02-T1) / ta2)÷((T01-T1) / ta1), which is the change pattern of the outdoor coil temperature after the air conditioner defrosts.

[0069] In some embodiments of the present invention, the controller is further configured to control the bottom plate heater to be turned off when a second preset time after defrosting is completed arrives.

[0070] In the above embodiment, the chassis heater is turned on before defrosting to preheat the chassis and remains on during the defrosting operation. After the defrosting is completed, in order to avoid the chassis heater being kept on and wasting the air conditioner's electricity, the chassis heater is controlled to be turned off after the defrosting is completed, after a second preset time is delayed, such as 10 minutes, to ensure that the frost on the chassis is completely melted, thereby saving electricity.

[0071] Furthermore, the controller is further configured to: obtain the defrost time of the air conditioner, and correct the second preset time according to the defrost time.

[0072] The conditions for exiting defrost vary depending on the degree of frost detected. The most significant difference lies in the defrost time. If the chassis heater is shut off with a constant delay, it may result in more frost during periods of long defrost times. If the chassis heater shuts off at the same second preset time, the frost in the chassis may not be fully melted, thus still posing a risk of clogging the chassis water outlet. Therefore, the second preset time needs to be adjusted based on the degree of frost. For long defrost times, the second preset time can be extended to, for example, 12 minutes; for short defrost times, it can be shortened to, for example, 8 minutes. This ensures that the chassis frost is fully melted while minimizing energy consumption.

[0073] The present invention further provides an air conditioner having an air conditioner controller according to the above-mentioned embodiment installed therein. The air conditioner controller monitors the changing pattern of the outdoor coil temperature after defrosting the air conditioner, predicts the time when the current defrost will arrive based on the changing pattern, and determines the time to start the chassis heater in advance of a preset time based on the current defrost arrival time. Compared to the prior art method of controlling the chassis heater to turn on based on the outdoor coil temperature, or only turning on the controller during the defrost process, the air conditioner of the present invention controls the chassis heater to turn on in advance before the next defrost based on the changing pattern of the outdoor coil temperature after defrosting, thereby effectively achieving early preheating of the chassis. Moreover, the first preset time for the early start is determined based on the changing pattern of the outdoor coil temperature before defrosting, and is not fixed. Therefore, the early start time can be determined based on the specific heating state before defrosting, thereby further effectively achieving the chassis preheating process, effectively preventing condensed water on the chassis from freezing during the defrost process, and completely solving the problem of water outlet blockage.

[0074] In the description of this specification, the reference terms "first embodiment", "second embodiment", "example", etc. mean that the specific method, device or feature described in conjunction with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, methods, devices or features described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0075] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A control method for defrosting an air conditioner, characterized in that: The control method includes: Monitor the changing pattern of outdoor coil temperature after defrosting of air conditioner; Predict the time when this defrost will arrive based on the changing rules; Determine the time for the chassis heater to be turned on in advance by a preset time according to the current defrost arrival time; The monitoring of the change of the outdoor coil temperature after defrosting of the air conditioner includes: Monitoring the time it takes for the outdoor coil temperature of the air conditioner to drop to a first preset temperature after two consecutive defrost operations to determine the change pattern; The method of predicting the time of arrival of defrost according to the change rule includes: Get the time when the last defrost arrived; Determine the time when this defrost is to be completed according to the change rule and the time when the previous defrost was started; The control method further includes: Get the outdoor coil temperature when the air conditioner starts heating after two consecutive defrosts; determining the variation rule based on the monitored time for the outdoor coil temperature to drop to the first preset temperature after two consecutive defrosting operations and the two outdoor coil temperatures; The change rule is specifically the rate of decrease of the outdoor coil temperature. Determining the time of arrival of this defrost according to the change rule and the time of the previous defrost start specifically includes: Calculate tc2 using the formula (tc2-ta2) / (tc1-ta1)=((Ts2-T1) / ta2)÷((Ts1-T1) / ta1), where ta1 and ta2 are the time it takes for the outdoor coil temperature to drop to the first preset temperature T1 after two defrosts, tc1 is the time it took to reach the previous defrost stage, tc2 is the time it took to reach the current defrost stage, and Ts1 and Ts2 are the outdoor coil temperatures at the start of heating after the air conditioner's two defrosts. The control method further includes: When a second preset time is reached after defrosting is completed, controlling the chassis heater to be turned off; The control method further includes: The defrost time of the air conditioner is obtained, and the second preset time is corrected according to the defrost time.

2. A controller for an air conditioner, characterized in that: The controller is configured to: monitor the changing pattern of the outdoor coil temperature after the air conditioner defrosts, predict the time when the defrost will arrive based on the changing pattern, and determine the time when the chassis heater is turned on in advance of the preset time based on the time when the defrost will arrive; The controller is used to execute the control method for defrosting an air conditioner as claimed in claim 1.

3. The controller according to claim 2, characterized in that When monitoring the changing pattern of the outdoor coil temperature after defrosting of the air conditioner, the controller is further configured to monitor the time it takes for the outdoor coil temperature to drop to a first preset temperature after two consecutive defrosting operations of the air conditioner to determine the changing pattern.

4. The controller according to claim 3, characterized in that When predicting the time of arrival of this defrost according to the change rule, the controller is further configured to: obtain the time of arrival of the previous defrost; and determine the time of arrival of this defrost according to the change rule and the time when the previous defrost was turned on.

5. An air conditioner, wherein the air conditioner controller according to any one of claims 2 to 4 is arranged inside the air conditioner.

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