Fan reverse circuit, air conditioner and control method

Abstract

The application provides a fan reversing circuit, an air conditioner and a control method. The fan reversing circuit comprises a first switching circuit and a second switching circuit. An input end of the first switching circuit is connected with a three-phase power supply of the air conditioner, an output end of the first switching circuit is connected with a fan of the air conditioner, and the first switching circuit is further connected with a control circuit of the air conditioner, for conducting and turning off under the control of the control circuit. An input end of the second switching circuit is connected with the three-phase power supply, an output end of the second switching circuit is connected with the fan, and the second switching circuit is further connected with the control circuit, for conducting and turning off under the control of the control circuit. When the air conditioner enters a defrosting mode, the second switching circuit is connected to reverse the fan. The application can improve the defrosting efficiency and avoid frost residues.

Description

Technical Field

[0001] This invention relates to the field of air conditioner technology, specifically to a fan reversal circuit, an air conditioner, and a control method. Background Technology

[0002] Currently, most air conditioners primarily function as coolers and heaters. Frost can form on either the cooling or heating modes. In cooling mode, the evaporator may frost when air circulation is insufficient; in heating mode, the outdoor unit may frost when there is a large temperature difference. Frost buildup can affect the normal operation of the air conditioner. Therefore, most air conditioners also have an automatic defrosting function. However, in existing models, the fan stops during defrosting, and only the compressor starts, leaving some frost residue and failing to completely remove the frost. Summary of the Invention

[0003] This invention provides a fan reversal circuit, an air conditioner, and a control method, aiming to solve the problem of incomplete defrosting and residue in current air conditioners.

[0004] In a first aspect, the present invention provides a fan reversal circuit, comprising a first switching circuit and a second switching circuit; the input terminal of the first switching circuit is connected to the three-phase power supply of the air conditioner, the output terminal of the first switching circuit is connected to the fan of the air conditioner, and the first switching circuit is also connected to the control circuit of the air conditioner for switching on and off under the control of the control circuit; the input terminal of the second switching circuit is connected to the three-phase power supply, the output terminal of the second switching circuit is connected to the fan, and the second switching circuit is also connected to the control circuit for switching on and off under the control of the control circuit; wherein, when the air conditioner enters defrost mode, the second switching circuit is activated to reverse the fan.

[0005] Furthermore, the first switching circuit includes a first relay; the input terminal of the first relay is connected to the three-phase power supply, the output terminal of the first relay is connected to the fan, and the controlled terminal of the first relay is also connected to the control circuit.

[0006] Furthermore, the input terminal of the first relay includes a first contact, a second contact, and a third contact; the first contact is connected to the U line of the three-phase power supply, the second contact is connected to the V line of the three-phase power supply, and the third contact is connected to the W line of the three-phase power supply.

[0007] Furthermore, the output terminal of the first relay includes a fourth contact, a fifth contact, and a sixth contact; the fourth contact, the fifth contact, and the sixth contact are all connected to the fan.

[0008] Furthermore, the second switching circuit includes a second relay; the input terminal of the second relay is connected to the three-phase power supply, the output terminal of the second relay is connected to the fan, and the controlled terminal of the second relay is also connected to the control circuit.

[0009] Furthermore, the input terminal of the second relay includes a seventh contact, an eighth contact, and a ninth contact; the seventh contact is connected to the U line of the three-phase power supply, the eighth contact is connected to the W line of the three-phase power supply, and the ninth contact is connected to the V line of the three-phase power supply.

[0010] Furthermore, the output terminal of the second relay includes a tenth contact, an eleventh contact, and a twelfth contact; the tenth contact, the eleventh contact, and the twelfth contact are all connected to the fan.

[0011] Secondly, the present invention provides an air conditioner, the air conditioner comprising a three-phase power supply, a control circuit, a fan, and a fan reversal circuit as described in any of the above.

[0012] Furthermore, the three-phase power supply is connected to the input terminals of the first and second switching circuits of the fan reversal circuit, the fan is connected to the output terminals of the first and second switching circuits, and the control circuit is connected to the first and second switching circuits.

[0013] Thirdly, the present invention provides a control method, the method comprising:

[0014] Detect the operating mode of the air conditioner;

[0015] If the air conditioner is in defrost mode, the second switching circuit of the air conditioner is turned on to reverse the fan of the air conditioner.

[0016] If the air conditioner completes defrosting, the second switch circuit is turned off to allow the fan to operate normally.

[0017] The fan reversal circuit, air conditioner, and control method disclosed in this invention include a first switching circuit and a second switching circuit. Both the first and second switching circuits are connected between the three-phase power supply and the fan, and are also connected to a control circuit. When the air conditioner is in cooling or heating mode, the first switching circuit is connected, and the three-phase power supply powers the fan through the first switching circuit, allowing the fan to operate normally. When the air conditioner enters defrost mode, the second switching circuit is connected, and the three-phase power supply powers the fan through the first and second switching circuits, causing the fan to reverse and blow the refrigerant from the inside to the outside of the heat exchanger, thus improving defrost efficiency and preventing frost residue. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a block diagram of a fan reversal circuit provided in an embodiment of the present invention;

[0020] Figure 2 This is a block diagram of a fan reversal circuit provided in another embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the structure of the first relay in the fan reversal circuit provided in an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the structure of the second relay in a fan reversal circuit provided in an embodiment of the present invention;

[0023] Figure 5 This is a circuit diagram of a fan reversal circuit provided in an embodiment of the present invention;

[0024] Figure 6 This is a flowchart illustrating a control method provided in an embodiment of the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be understood that, when used in this specification and the appended claims, the terms “comprising” and “including” indicate the presence of the described features, integrals, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, operations, elements, components and / or collections thereof.

[0027] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0028] Furthermore, the directional terms used in this invention, such as "up," "down," "front," "back," "left," "right," "inner," "outer," and "side," are merely for reference to the accompanying drawings and the product's usage state. Therefore, the directional terms used are for illustrating and understanding this invention, and not for limiting it. Additionally, in the accompanying drawings, structures that are similar or identical are indicated by the same reference numerals.

[0029] See Figures 1 to 5 , Figure 1 This is a block diagram of a fan reversal circuit 100 provided in an embodiment of the present invention; Figure 2 This is a block diagram of a fan reversal circuit 100 provided in another embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the first relay KA1 in the fan reversal circuit 100 provided in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the structure of the second relay KA2 in the fan reversal circuit 100 provided in an embodiment of the present invention; Figure 5 This is a circuit diagram of a fan reversal circuit 100 provided in an embodiment of the present invention. Figure 1 As shown, the fan reversal circuit 100 includes a first switching circuit 10 and a second switching circuit 20. The input terminal of the first switching circuit 10 is connected to the three-phase power supply 200 of the air conditioner, and the output terminal of the first switching circuit 10 is connected to the fan 300 of the air conditioner. The first switching circuit 10 is also connected to the control circuit 400 of the air conditioner and is used to turn on and off under the control of the control circuit 400. The input terminal of the second switching circuit 20 is connected to the three-phase power supply 200, and the output terminal of the second switching circuit 20 is connected to the fan 300. The second switching circuit 20 is also connected to the control circuit 400 and is used to turn on and off under the control of the control circuit 400. When the air conditioner enters the defrost mode, the second switching circuit 20 is activated to reverse the fan 300.

[0031] Specifically, the fan reversal circuit 100 may include a first switching circuit 10 and a second switching circuit 20. The input terminal of the first switching circuit 10 is connected to the three-phase power supply 200, and the output terminal of the first switching circuit 10 is connected to the fan 300. The input terminal of the second switching circuit 20 is connected to the three-phase power supply 200, and the output terminal of the second switching circuit 20 is connected to the fan 300. That is, the first switching circuit 10 and the second switching circuit 20 are connected between the three-phase power supply 200 and the fan 300. When neither the first switching circuit 10 nor the second switching circuit 20 is connected, the fan 300 does not work. The fan 300 is the fan 300 inside the air conditioner. Under normal circumstances, when the air conditioner is in cooling mode or heating mode, the fan 300 runs in the forward direction. The specific structure of the air conditioner can be a structure common in the art, including but not limited to components such as evaporators and heat exchangers. The first switching circuit 10 and the second switching circuit 20 are mainly used to control the power supply from the three-phase power supply 200 to the fan 300. They may include a switching element, which may be a relay or a multi-function switch. Preferably, both the first switching circuit 10 and the second switching circuit 20 may include a relay.

[0032] like Figure 2 As shown, the three-phase power supply 200 includes a U line, a V line, and a W line. Both the first switching circuit 10 and the second switching circuit 20 may include three input terminals, each connected to one phase line of the three-phase power supply 200. For example, the first switching circuit 10 may include a first input terminal, a second input terminal, and a third input terminal; the second switching circuit 20 may include a fourth input terminal, a fifth input terminal, and a sixth input terminal. The first input terminal of the first switching circuit 10 can be connected to the U line of the three-phase power supply 200, the second input terminal can be connected to the V line of the three-phase power supply 200, and the third input terminal can be connected to the W line of the three-phase power supply 200. The fourth input terminal of the second switching circuit 20 can be connected to the U line of the three-phase power supply 200, the fifth input terminal can be connected to the W line of the three-phase power supply 200, and the sixth input terminal can be connected to the V line of the three-phase power supply 200. The first switching circuit 10 may also include a first output terminal, a second output terminal, and a third output terminal; the second switching circuit 20 may also include a fourth output terminal, a fifth output terminal, and a sixth output terminal. The first output terminal of the first switching circuit 10 is connected to the U-phase input terminal of the fan 300, the second output terminal is connected to the V-phase input terminal of the fan 300, and the third output terminal is connected to the W-phase input terminal of the fan 300. The fourth output terminal of the second switching circuit 20 is connected to the U-phase input terminal of the fan 300, the fifth output terminal is connected to the V-phase input terminal of the fan 300, and the sixth output terminal is connected to the W-phase input terminal of the fan 300.

[0033] When the air conditioner is in cooling or heating mode, the control circuit 400 controls the first switch circuit 10 to turn on and the second switch circuit 20 to turn off. The three-phase power supply 200 supplies power to the fan 300 through the first switch circuit 10. At this time, the three phase lines of the three-phase power supply 200 are normally connected to the fan 300. If the air conditioner is in defrost mode, the control circuit 400 controls the second switch circuit 20 to turn on. At this time, the first switch circuit 10 is also turned on, and the first switch circuit 10 and the second switch circuit 20 are connected in parallel. The current of the U line of the three-phase power supply 200 enters the first input terminal of the first switch circuit 10 and the fourth input terminal of the second switch circuit 20, the current of the V line enters the second input terminal of the first switch circuit 10 and the sixth input terminal of the second switch circuit 20, and the current of the W line enters the third input terminal of the first switch circuit 10 and the fifth input terminal of the second switch circuit 20. Simultaneously, the first output terminal of the first switching circuit 10 and the fourth output terminal of the second switching circuit 20 both output U-phase current and enter the U-phase input terminal of the fan 300. The second output terminal of the first switching circuit 10 outputs V-phase current and the fifth output terminal of the second switching circuit 20 outputs W-phase current, which enters the V-phase input terminal of the fan 300. The W-phase current output from the third output terminal of the first switching circuit 10 and the V-phase current output from the sixth output terminal of the second switching circuit 20 enter the W-phase input terminal of the fan 300, causing the fan 300 to rotate in reverse. The reverse rotation of the fan 300 inside the air conditioner can blow the refrigerant from the inside to the outside of the finned heat exchanger, causing the temperature of the copper tubes in the external flow path of the finned heat exchanger to rise rapidly, increasing the defrosting speed. At the same time, the water in the drip tray flows more quickly through the drain hole to the outside of the unit, accelerating the discharge of condensate and preventing the internal condensate from accumulating and frosting again.

[0034] See Figure 3 As a further embodiment, the first switching circuit 10 includes a first relay KA1; the input terminal of the first relay KA1 is connected to the three-phase power supply 200, the output terminal of the first relay KA1 is connected to the fan 300, and the controlled terminal of the first relay KA1 is also connected to the control circuit 400.

[0035] Furthermore, the input terminal of the first relay KA1 includes a first contact, a second contact, and a third contact; the first contact is connected to the U line of the three-phase power supply 200, the second contact is connected to the V line of the three-phase power supply 200, and the third contact is connected to the W line of the three-phase power supply 200.

[0036] Furthermore, the output terminal of the first relay KA1 includes a fourth contact, a fifth contact, and a sixth contact; the fourth contact, the fifth contact, and the sixth contact are all connected to the fan 300.

[0037] The input terminals of the first relay KA1 may include a first contact, a second contact, and a third contact, and the output terminals of the first relay KA1 may include a fourth contact, a fifth contact, and a sixth contact. The first contact serves as the first input terminal of the first switching circuit 10, the second contact as the second input terminal of the first switching circuit 10, the third contact as the third input terminal of the first switching circuit 10, the fourth contact as the first output terminal of the first switching circuit 10, the fifth contact as the second output terminal of the first switching circuit 10, and the sixth contact as the third output terminal of the first switching circuit 10. Figure 5 As shown, the first contact is connected to the U-phase line of the three-phase power supply 200, the second contact is connected to the V-phase line of the three-phase power supply 200, the third contact is connected to the W-phase line of the three-phase power supply 200, the fourth contact is connected to the U-phase input terminal of the fan 300, the fifth contact is connected to the V-phase input terminal of the fan 300, and the sixth contact is connected to the W-phase input terminal of the fan 300. When the first switching circuit 10 is connected, the three-phase current of the three-phase power supply 200 supplies power to the fan 300 through the first relay KA1, and the fan 300 operates normally.

[0038] See Figure 4 As a further embodiment, the second switching circuit 20 includes a second relay KA2; the input terminal of the second relay KA2 is connected to the three-phase power supply 200, the output terminal of the second relay KA2 is connected to the fan 300, and the controlled terminal of the second relay KA2 is also connected to the control circuit 400.

[0039] Furthermore, the input terminal of the second relay KA2 includes a seventh contact, an eighth contact, and a ninth contact; the seventh contact is connected to the U line of the three-phase power supply 200, the eighth contact is connected to the W line of the three-phase power supply 200, and the ninth contact is connected to the V line of the three-phase power supply 200.

[0040] Furthermore, the output terminal of the second relay KA2 includes a tenth contact, an eleventh contact, and a twelfth contact; the tenth contact, the eleventh contact, and the twelfth contact are all connected to the fan 300.

[0041] The input terminals of the second relay KA2 may include a seventh contact, an eighth contact, and a ninth contact, and the output terminals of the second relay KA2 may include a tenth contact, an eleventh contact, and a twelfth contact. The seventh contact serves as the first input terminal of the second switching circuit 20, the eighth contact as the second input terminal, the ninth contact as the third input terminal, the tenth contact as the first output terminal, the eleventh contact as the second output terminal, and the twelfth contact as the third output terminal. Figure 5As shown, the seventh contact is connected to the U-phase line of the three-phase power supply 200, the eighth contact is connected to the W-phase line of the three-phase power supply 200, the ninth contact is connected to the V-phase line of the three-phase power supply 200, the tenth contact is connected to the U-phase input terminal of the fan 300, the eleventh contact is connected to the V-phase input terminal of the fan 300, and the twelfth contact is connected to the W-phase input terminal of the fan 300. When the first switching circuit 10 and the second switching circuit 20 are simultaneously connected, the three-phase current of the three-phase power supply 200 supplies power to the fan 300 through the first relay KA1 and the second relay KA2, and the fan 300 rotates in reverse.

[0042] like Figure 5 As shown, Figure 5 Both the first relay KA1 and the second relay KA2 are connected to the control circuit 400 via two wires. The control circuit 400 can control the first relay KA1 and the second relay KA2 by controlling whether the two wires are connected or not. For example, when the wire between the second relay KA2 and the control circuit 400 is connected, both the second relay KA2 and the first relay KA1 are connected. When the wire between the first relay KA1 and the control circuit is connected, the first relay KA1 is connected and the second relay KA2 is disconnected.

[0043] The present invention also provides an air conditioner, the air conditioner comprising a three-phase power supply 200, a control circuit 400, a fan 300, and a fan reversal circuit 100 as described in any of the above embodiments; the three-phase power supply 200 is connected to the input terminals of the first switching circuit 10 and the second switching circuit 20 of the fan reversal circuit 100, the fan 300 is connected to the output terminals of the first switching circuit 10 and the second switching circuit 20, and the control circuit 400 is connected to the first switching circuit 10 and the second switching circuit 20.

[0044] Specifically, the fan reversal circuit 100 may include a first switching circuit 10 and a second switching circuit 20. The input terminal of the first switching circuit 10 is connected to the three-phase power supply 200, and the output terminal of the first switching circuit 10 is connected to the fan 300. The input terminal of the second switching circuit 20 is connected to the three-phase power supply 200, and the output terminal of the second switching circuit 20 is connected to the fan 300. That is, the first switching circuit 10 and the second switching circuit 20 are connected between the three-phase power supply 200 and the fan 300. When neither the first switching circuit 10 nor the second switching circuit 20 is connected, the fan 300 does not work. The fan 300 is the fan 300 inside the air conditioner. Under normal circumstances, when the air conditioner is in cooling mode or heating mode, the fan 300 runs in the forward direction. The specific structure of the air conditioner can be a structure common in the art, including but not limited to components such as evaporators and heat exchangers. The first switching circuit 10 and the second switching circuit 20 are mainly used to control the power supply from the three-phase power supply 200 to the fan 300. They may include a switching element, which may be a relay or a multi-function switch. Preferably, both the first switching circuit 10 and the second switching circuit 20 may include a relay.

[0045] like Figure 2 As shown, the three-phase power supply 200 includes a U line, a V line, and a W line. Both the first switching circuit 10 and the second switching circuit 20 may include three input terminals, each connected to one phase line of the three-phase power supply 200. For example, the first switching circuit 10 may include a first input terminal, a second input terminal, and a third input terminal; the second switching circuit 20 may include a fourth input terminal, a fifth input terminal, and a sixth input terminal. The first input terminal of the first switching circuit 10 can be connected to the U line of the three-phase power supply 200, the second input terminal can be connected to the V line of the three-phase power supply 200, and the third input terminal can be connected to the W line of the three-phase power supply 200. The fourth input terminal of the second switching circuit 20 can be connected to the U line of the three-phase power supply 200, the fifth input terminal can be connected to the W line of the three-phase power supply 200, and the sixth input terminal can be connected to the V line of the three-phase power supply 200. The first switching circuit 10 may also include a first output terminal, a second output terminal, and a third output terminal; the second switching circuit 20 may also include a fourth output terminal, a fifth output terminal, and a sixth output terminal. The first output terminal of the first switching circuit 10 is connected to the U-phase input terminal of the fan 300, the second output terminal is connected to the V-phase input terminal of the fan 300, and the third output terminal is connected to the W-phase input terminal of the fan 300. The fourth output terminal of the second switching circuit 20 is connected to the U-phase input terminal of the fan 300, the fifth output terminal is connected to the V-phase input terminal of the fan 300, and the sixth output terminal is connected to the W-phase input terminal of the fan 300.

[0046] When the air conditioner is in cooling or heating mode, the control circuit 400 controls the first switch circuit 10 to turn on and the second switch circuit 20 to turn off. The three-phase power supply 200 supplies power to the fan 300 through the first switch circuit 10. At this time, the three phase lines of the three-phase power supply 200 are normally connected to the fan 300. If the air conditioner is in defrost mode, the control circuit 400 controls the second switch circuit 20 to turn on. At this time, the first switch circuit 10 is also turned on, and the first switch circuit 10 and the second switch circuit 20 are connected in parallel. The current of the U line of the three-phase power supply 200 enters the first input terminal of the first switch circuit 10 and the fourth input terminal of the second switch circuit 20, the current of the V line enters the second input terminal of the first switch circuit 10 and the sixth input terminal of the second switch circuit 20, and the current of the W line enters the third input terminal of the first switch circuit 10 and the fifth input terminal of the second switch circuit 20. Simultaneously, the first output terminal of the first switching circuit 10 and the fourth output terminal of the second switching circuit 20 both output U-phase current and enter the U-phase input terminal of the fan 300. The second output terminal of the first switching circuit 10 outputs V-phase current and the fifth output terminal of the second switching circuit 20 outputs W-phase current, which enters the V-phase input terminal of the fan 300. The W-phase current output from the third output terminal of the first switching circuit 10 and the V-phase current output from the sixth output terminal of the second switching circuit 20 enter the W-phase input terminal of the fan 300, causing the fan 300 to rotate in reverse. The reverse rotation of the fan 300 inside the air conditioner can blow the refrigerant from the inside to the outside of the finned heat exchanger, causing the temperature of the copper tubes in the external flow path of the finned heat exchanger to rise rapidly, increasing the defrosting speed. At the same time, the water in the drip tray flows more quickly through the drain hole to the outside of the unit, accelerating the discharge of condensate and preventing the internal condensate from accumulating and frosting again.

[0047] See Figure 6 The present invention also provides a control method, which is applied to the air conditioner described in any of the above embodiments, the method comprising steps S110-S130.

[0048] S110, Detect the operating mode of the air conditioner.

[0049] In this embodiment of the invention, the normal operating modes of the air conditioner include cooling mode and heating mode. When the air conditioner reaches a certain level of frost buildup, it enters defrost mode. Therefore, the operating mode of the air conditioner is monitored in real time during operation.

[0050] S120, if the air conditioner is in defrost mode, the second switch circuit of the air conditioner is turned on to reverse the fan of the air conditioner.

[0051] In this embodiment of the invention, air conditioners typically only frost rapidly in cooling or heating mode, creating enough frost to trigger the defrost mode. Therefore, when the air conditioner is detected to be in defrost mode, the first switching circuit is usually already connected, requiring only the second switching circuit to be turned on. When both the first and second switching circuits are on, they are connected in parallel. The current in the U-line of the three-phase power supply enters the first input terminal of the first switching circuit and the fourth input terminal of the second switching circuit, the current in the V-line enters the second input terminal of the first switching circuit and the sixth input terminal of the second switching circuit, and the current in the W-line enters the third input terminal of the first switching circuit and the fifth input terminal of the second switching circuit. Simultaneously, the first output terminal of the first switching circuit and the fourth output terminal of the second switching circuit both output U-phase current, which enters the U-phase input terminal of the fan. The second output terminal of the first switching circuit outputs V-phase current, and the fifth output terminal of the second switching circuit outputs W-phase current, which enters the V-phase input terminal of the fan. The W-phase current output from the third output terminal of the first switching circuit and the V-phase current output from the sixth output terminal of the second switching circuit also enter the W-phase input terminal of the fan, causing the fan to rotate in reverse. The reverse rotation of the fan inside the air conditioner blows the refrigerant from the inside to the outside of the finned heat exchanger, causing the temperature of the copper tubes in the external flow path of the finned heat exchanger to rise rapidly, increasing the defrosting speed. At the same time, the water in the drip tray flows more quickly through the drain hole to the outside of the unit, accelerating the discharge of condensate and preventing internal condensate buildup and re-frost formation.

[0052] S130, if the air conditioner has completed defrosting, the second switch circuit is controlled to turn off so that the fan can operate normally.

[0053] In this embodiment of the invention, when the air conditioner completes defrosting, it can be confirmed whether the conditions for exiting the defrosting mode are met. When the conditions for exiting the defrosting mode are met, the second switch circuit is controlled to open. Preferably, the conditions for exiting the defrosting mode can be checked multiple times within a certain period of time, and the second switch circuit is controlled to open only when all checks are satisfactory.

[0054] In some embodiments, such as this one, the control method further includes step S140.

[0055] S140, if the air conditioner is in cooling mode or heating mode, then control the first switching circuit to turn on.

[0056] In this embodiment of the invention, when the air conditioner is in cooling mode or heating mode, the first switch circuit is turned on and the second switch circuit is turned off to ensure that the fan operates normally.

[0057] The fan reversal circuit, air conditioner, and control method disclosed in this invention can improve defrosting efficiency and avoid frost residue by reversing the fan.

[0058] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A fan reversal circuit, characterized in that, Applied to air conditioners, including: A first switching circuit is connected to the three-phase power supply of the air conditioner at its input terminal and to the fan of the air conditioner at its output terminal. The first switching circuit is also connected to the control circuit of the air conditioner and is used to turn the circuit on and off under the control of the control circuit. The second switching circuit has its input terminal connected to the three-phase power supply and its output terminal connected to the fan. The second switching circuit is also connected to the control circuit and is used to turn on and off under the control of the control circuit. When the air conditioner enters defrost mode, the second switching circuit is activated to reverse the fan. The first switching circuit includes a first relay; the input terminal of the first relay is connected to the three-phase power supply, the output terminal of the first relay is connected to the fan, and the controlled terminal of the first relay is also connected to the control circuit. The input terminal of the first relay includes a first contact, a second contact, and a third contact; The first contact is connected to the U line of the three-phase power supply, the second contact is connected to the V line of the three-phase power supply, and the third contact is connected to the W line of the three-phase power supply.

2. The fan reversal circuit according to claim 1, characterized in that, The output terminal of the first relay includes a fourth contact, a fifth contact, and a sixth contact; The fourth contact, the fifth contact, and the sixth contact are all connected to the fan.

3. The fan reversal circuit according to claim 1, characterized in that, The second switching circuit includes a second relay; The input terminal of the second relay is connected to the three-phase power supply, the output terminal of the second relay is connected to the fan, and the controlled terminal of the second relay is also connected to the control circuit.

4. The fan reversal circuit according to claim 3, characterized in that, The input terminals of the second relay include a seventh contact, an eighth contact, and a ninth contact; The seventh contact is connected to the U line of the three-phase power supply, the eighth contact is connected to the W line of the three-phase power supply, and the ninth contact is connected to the V line of the three-phase power supply.

5. The fan reversal circuit according to claim 4, characterized in that, The output terminals of the second relay include a tenth contact, an eleventh contact, and a twelfth contact; The tenth contact, the eleventh contact, and the twelfth contact are all connected to the fan.

6. An air conditioner, characterized in that, Includes a three-phase power supply, a control circuit, a fan, and a fan reversal circuit as described in any one of claims 1 to 5; The three-phase power supply is connected to the input terminals of the first and second switching circuits of the fan reversal circuit, the fan is connected to the output terminals of the first and second switching circuits, and the control circuit is connected to the first and second switching circuits.

7. A control method, characterized in that, Applied to the air conditioner as described in claim 6, comprising: Detect the operating mode of the air conditioner; If the air conditioner is in defrost mode, the second switching circuit of the air conditioner is turned on to reverse the fan of the air conditioner. If the air conditioner completes defrosting, the second switch circuit is turned off to allow the fan to operate normally.

8. The method according to claim 7, characterized in that, The method further includes: If the air conditioner is in cooling mode or heating mode, the first switching circuit is turned on.

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