Air conditioner and control method of air conditioner

Abstract

The invention discloses an air conditioner and a control method of the air conditioner, the air conditioner comprises an indoor fan, an electric heating detection circuit and a controller, and the controller is used for starting electric heating for a preset time after power-on initialization; detecting whether the air conditioner is provided with an electric heater or not according to the level signal output by the electric heating detection circuit within the preset time; when it is detected that the air conditioner is provided with the electric heater, whether an air conditioner starting command and an electric heating starting command sent by the wire controller are received or not is judged; and when the air conditioner starting command and the electric heating starting command are received, cold air prevention control is not executed, the air conditioner is controlled to enter a heating mode after being started, and an indoor fan is controlled to be started and run at the preset rotating speed. Whether the air conditioner is provided with the electric heater or not can be automatically detected, whether cold air prevention control is executed or not is selected according to the detection result, potential safety hazards caused by the fact that the temperature of the electric heating surface is too high are avoided, and therefore the operation reliability and safety of the air conditioner and user comfort are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioner control, and particularly to an air conditioner and a control method thereof. Background Art

[0002] In vertical duct air conditioners, rooftop units and other models in the North American market, electric heating wires are generally optional for installation, and the power of the installed electric heating wires is generally between 5 kW and 20 kW. With a relatively large power, after the electric heating is turned on, the surface temperature thereof is relatively high, reaching 300°C to 800°C.

[0003] However, after the user selects and installs the electric heating wire, since the main control board does not know whether there is an electric heating wire, when starting up, even if the electric heating is turned on, the anti-cold wind control logic will be executed, which will cause the surface temperature of the electric heating wire to be too high. The new standard requires the use of flammable refrigerant 454B. The too high surface temperature of the electric heating wire may ignite the refrigerant, posing a safety hazard, thus affecting the reliability, safety and user comfort of the air conditioner operation. Summary of the Invention

[0004] An object of embodiments of the present invention is to provide an air conditioner and a control method thereof, which can automatically detect whether an electric heating is installed in the air conditioner and select whether to execute the anti-cold wind control according to the detection result, so as to avoid potential safety hazards caused by too high surface temperature of the electric heating, thereby improving the reliability, safety and user comfort of the air conditioner operation.

[0005] To achieve the above object, an embodiment of the present invention provides an air conditioner, which includes:

[0006] A refrigerant circuit in which a refrigerant circulates in a refrigeration cycle through a compressor, a condenser, a throttling component and an evaporator in sequence, one of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger;

[0007] An indoor fan for blowing the air after heat exchange by the indoor heat exchanger into the room;

[0008] An electric heating detection circuit for connecting to the electric heating and outputting a level signal when powered on;

[0009] A controller connected to the electric heating detection circuit, for:

[0010] After power-on initialization, turn on the electric heating and keep it for a preset time, and detect whether the air conditioner is installed with an electric heating according to the level signal output by the electric heating detection circuit within the preset time;

[0011] When it is detected that the air conditioner is installed with an electric heating, determine whether an air conditioner startup command and an electric heating turn-on command sent by a wired controller are received;

[0012] When receiving the air conditioner startup command and the electric heating startup command, the anti-cold wind control is not executed, the air conditioner is controlled to enter the heating mode after startup, and the indoor fan is controlled to start and operate at a preset speed.

[0013] Further, the electric heating detection circuit includes a signal input module, an electric heating connection module, a rectification module, and a zero-crossing detection module;

[0014] The first input terminal of the signal input module is used to connect to the AC power signal, the second input terminal of the signal input module is connected to the controller, and the output terminal of the signal input module is connected to the first end of the electric heating connection module;

[0015] The first end and the second end of the electric heating connection module are used to connect to the electric heating, and the first end and the second end of the electric heating connection module are respectively connected to the first input terminal and the second input terminal of the rectification module;

[0016] The first output terminal and the second output terminal of the rectification module are respectively connected to the first input terminal and the second input terminal of the zero-crossing detection module;

[0017] The first output terminal of the zero-crossing detection module is connected to the controller, and the second output terminal of the zero-crossing detection module is grounded.

[0018] Further, the signal input module includes a relay, two contact terminals of the relay are respectively connected to the first input terminal and the output terminal of the signal input module, and two coil terminals of the relay are respectively connected to the second input terminal of the signal input module and the power supply.

[0019] Further, the electric heating connection module includes an electric heating interface, and two interface terminals of the electric heating interface are respectively connected to the first end and the second end of the electric heating connection module.

[0020] Further, the zero-crossing detection module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, and a switching tube;

[0021] The first end of the first resistor is connected to the first input terminal of the zero-crossing detection module, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the second input terminal of the zero-crossing detection module;

[0022] The first end of the third resistor is connected to the power supply, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the first output terminal of the zero-crossing detection module;

[0023] The control terminal of the switching tube is connected to the second terminal of the first resistor, the input terminal of the switching tube is connected to the second terminal of the third resistor, and the output terminal of the switching tube is connected to the second output terminal of the zero-crossing detection module;

[0024] The first terminal of the first capacitor is connected to the second terminal of the first resistor, and the second terminal of the first capacitor is connected to the second input terminal of the zero-crossing detection module;

[0025] The first terminal of the second capacitor is connected to the second terminal of the fourth resistor, the second terminal of the second capacitor is connected to the second output terminal of the zero-crossing detection module, and the second input terminal of the zero-crossing detection module is connected to the second output terminal of the zero-crossing detection module.

[0026] Further, the controller detects whether the air conditioner is equipped with electric heating according to the level signal output by the electric heating detection circuit within the preset time, specifically including:

[0027] Detect whether the preset level change rule is satisfied according to the level signal output by the electric heating detection circuit within the preset time;

[0028] When the level change rule is satisfied, it is determined that the air conditioner is equipped with electric heating;

[0029] When the level change rule is not satisfied, it is determined that the air conditioner is not equipped with electric heating.

[0030] Further, the level change rule is: the level signal output by the electric heating detection circuit within the preset time includes n high-level pulses; where n≥2.

[0031] Further, the controller is further configured to:

[0032] When receiving the air conditioner startup command and not receiving the electric heating startup command, perform anti-cold wind control; where the anti-cold wind control includes: controlling the air conditioner to enter the heating mode after startup, controlling the indoor fan not to start, and adjusting the operating speed of the indoor fan according to the indoor coil temperature until the preset speed is reached.

[0033] Further, the controller is further configured to:

[0034] When it is detected that the air conditioner is not equipped with electric heating, perform anti-cold wind control; where the anti-cold wind control includes: controlling the air conditioner to enter the heating mode after startup, controlling the indoor fan not to start, and adjusting the operating speed of the indoor fan according to the indoor coil temperature until the preset speed is reached.

[0035] To achieve the above object, an embodiment of the present invention further provides a control method for an air conditioner, which is applicable to the air conditioner described in any one of the above, and the method is executed by the controller. The method includes:

[0036] After power-on initialization, turn on the electric heating and continue for a preset time, and detect whether the electric heating is installed in the air conditioner according to the level signal output by the electric heating detection circuit within the preset time;

[0037] When it is detected that the electric heating is installed in the air conditioner, determine whether an air conditioner startup command and an electric heating turn-on command sent by the wired controller are received;

[0038] When the air conditioner startup command and the electric heating turn-on command are received, do not perform anti-cold wind control, control the air conditioner to enter the heating mode after startup, and control the indoor fan to start and operate at a preset speed.

[0039] Compared with the prior art, an air conditioner and a control method for the air conditioner provided by an embodiment of the present invention. The air conditioner includes: a refrigerant circuit in which refrigerant circulates in sequence through a compressor, a condenser, a throttling component, and an evaporator in a refrigeration cycle, one of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger; an indoor fan for blowing the air after heat exchange by the indoor heat exchanger into the room; an electric heating detection circuit for connecting the electric heating and outputting a level signal when powered on; a controller connected to the electric heating detection circuit for: after power-on initialization, turning on the electric heating and continuing for a preset time, and detecting whether the electric heating is installed in the air conditioner according to the level signal output by the electric heating detection circuit within the preset time; when it is detected that the electric heating is installed in the air conditioner, determining whether an air conditioner startup command and an electric heating turn-on command sent by the wired controller are received; when the air conditioner startup command and the electric heating turn-on command are received, not performing anti-cold wind control, controlling the air conditioner to enter the heating mode after startup, and controlling the indoor fan to start and operate at a preset speed. The embodiment of the present invention can automatically detect whether the electric heating is installed in the air conditioner, and select whether to perform anti-cold wind control according to the detection result, so as to avoid potential safety hazards caused by too high surface temperature of the electric heating, thereby improving the reliability, safety, and user comfort of the air conditioner operation. Description of the Drawings

[0040] Figure 1 is a schematic diagram of the external structure of an air conditioner provided by an embodiment of the present invention;

[0041] Figure 2 is a schematic diagram of the internal structure of an air conditioner provided by an embodiment of the present invention;

[0042] Figure 3 is a flowchart of the operation of the controller of an air conditioner provided by an embodiment of the present invention;

[0043] Figure 4 is a structural block diagram of an electric heating detection circuit provided by an embodiment of the present invention;

[0044] Figure 5 is a schematic diagram of the principle of an electric heating detection circuit provided by an embodiment of the present invention;

[0045] Figure 6 is a waveform diagram of an electric heating detection circuit provided by an embodiment of the present invention;

[0046] Figure 7 is a working flowchart of a controller of an air conditioner provided by another embodiment of the present invention;

[0047] Figure 8 is a working flowchart of a controller of an air conditioner provided by still another embodiment of the present invention;

[0048] Figure 9 is a working flowchart of a controller of an air conditioner provided by still another embodiment of the present invention;

[0049] Figure 10 is a schematic flowchart of a control method of an air conditioner provided by an embodiment of the present invention. Specific embodiments

[0050] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0051] Refer to Figure 1 and Figure 2 as shown, wherein, Figure 1 is a schematic diagram of the external structure of an air conditioner provided by an embodiment of the present invention, Figure 2 is a schematic diagram of the internal structure of an air conditioner provided by an embodiment of the present invention; as Figure 1 shown, the external structure of the air conditioner includes an indoor unit 100 and an outdoor unit 200. Among them, the indoor unit 100 is used to adjust the temperature and humidity of the indoor air, the outdoor unit 200 is connected to the indoor unit 100 through a connection pipe, the indoor unit 100 is generally installed indoors, and the outdoor unit 200 is generally installed outdoors.

[0052] As Figure 2As shown, the indoor unit 100 of the air conditioner includes an indoor heat exchanger, an indoor fan, and an indoor blower. Among them, the indoor heat exchanger can achieve a refrigeration effect by exchanging heat between the latent heat of evaporation of the refrigerant and the indoor air. The indoor fan is driven by the indoor blower, and the indoor blower is used to blow the air after heat exchange by the indoor heat exchanger into the room. That is to say, by driving the indoor fan with the indoor blower, an air flow of the indoor air passing through the indoor heat exchanger can be generated to promote the heat exchange between the refrigerant flowing in the heat transfer tube and the indoor air.

[0053] As Figure 2 shown, the outdoor unit 200 of the air conditioner includes a compressor, a four-way valve, an outdoor heat exchanger, a throttling component, an outdoor fan, and an outdoor blower. Among them, the compressor is used to compress the refrigerant gas with low temperature and low pressure into a refrigerant gas with high temperature and high pressure. The four-way valve is used to control the flow direction of the refrigerant in the refrigerant circuit so as to switch between the outdoor heat exchanger and the indoor heat exchanger as a condenser and an evaporator. The outdoor heat exchanger is used to exchange heat between the refrigerant flowing inside and the outdoor air. The throttling component is used to throttle the refrigerant flowing through. The outdoor fan is driven by the outdoor blower. By driving the outdoor fan with the outdoor blower, an air flow of the outdoor air passing through the outdoor heat exchanger can be generated to promote the heat exchange between the refrigerant flowing in the heat transfer tube and the outdoor air.

[0054] Combined with Figure 1 and Figure 2 shown, in the embodiment of the present invention, the air conditioner includes a refrigerant circuit in which the refrigerant circulates in sequence through a compressor, a condenser, a throttling component, and an evaporator in a refrigeration cycle. One of the condenser and the evaporator is the outdoor heat exchanger, and the other is the indoor heat exchanger.

[0055] In the embodiment of the present invention, the air conditioner further includes an electric heating detection circuit. The electric heating detection circuit is used to connect to the electric heating, and when powered on, the electric heating detection circuit outputs a level signal to the controller in the air conditioner (for example, the MCU of the main control board of the air conditioner), and this level signal can be used to detect whether the electric heating is installed in the air conditioner.

[0056] In the embodiment of the present invention, the air conditioner further includes a controller. The controller is used to control the operation of each component in the air conditioner so that each component of the air conditioner operates to achieve various functions of the air conditioner. Further, the controller is used to perform corresponding control on the air conditioner by adopting the technical solution provided in the embodiment of the present invention to solve the technical problems to be solved in the embodiment of the present invention and achieve the technical effects that can be achieved in the embodiment of the present invention.

[0057] As one of the optional embodiments, the controller is connected to the electric heating detection circuit and is used for:

[0058] After power-on initialization, turn on the electric heating and continue for a preset time, and detect whether the electric heating is installed in the air conditioner according to the level signal output by the electric heating detection circuit within the preset time;

[0059] When it is detected that the electric heating is installed in the air conditioner, determine whether an air conditioner startup command and an electric heating startup command sent by the wired controller are received;

[0060] When the air conditioner startup command and the electric heating startup command are received, do not perform anti-cold wind control, control the air conditioner to enter the heating mode after startup, and control the indoor fan to start and operate at a preset speed.

[0061] Combined Figure 3 As shown, it is a working flowchart of a controller of an air conditioner provided by an embodiment of the present invention. In the specific implementation of the embodiment of the present invention, the specific working process of the controller is as follows: The controller first performs power-on initialization ( Figure 3 step S11 shown), then forcibly turns on the electric heating and continues for a preset time ( Figure 3 step S12 shown). Since the electric heating detection circuit outputs a level signal to the controller when powered on, during the continuous process of the controller forcibly starting the electric heating, the electric heating detection circuit will always output a level signal to the controller. Then, the controller can detect and determine whether the electric heating is installed in the air conditioner according to the level signal output by the electric heating detection circuit within the preset time ( Figure 3 step S13 shown); When the controller detects that the electric heating is installed in the air conditioner, further determine whether an air conditioner startup command and an electric heating startup command sent by the wired controller are received ( Figure 3 step S14 shown); When the controller determines that the air conditioner startup command and the electric heating startup command sent by the wired controller are received, it is determined that the air conditioner does not perform anti-cold wind control. At this time, the controller will control the air conditioner to start according to the received air conditioner startup command, and control the air conditioner to enter the heating mode after startup. Further, the controller will control the indoor fan to start immediately, and there is no need to adjust the speed of the indoor fan according to the indoor coil temperature (the indoor coil temperature can be obtained by real-time detection by a temperature sensor arranged on the indoor coil), and directly control the indoor fan to operate at a preset speed ( Figure 3 step S15 shown).

[0062] It should be noted that the duration of forcibly starting the electric heating after the controller is powered on and initialized (i.e., the preset time) can be set according to actual needs, and the embodiment of the present invention does not make specific limitations. For example, the preset time can be set to 500 ms.

[0063] It should be noted that after the controller controls the indoor fan to run at a preset speed, the speed of the indoor fan remains unchanged and always runs at the preset speed.

[0064] An air conditioner provided by an embodiment of the present invention includes a refrigerant circuit in which a refrigerant circulates in a refrigeration cycle through a compressor, a condenser, a throttling component, and an evaporator in sequence. One of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger; it further includes an indoor fan for blowing the air after heat exchange by the indoor heat exchanger into the room; it further includes an electric heating detection circuit for connecting to the electric heating and outputting a level signal when powered on; it further includes a controller connected to the electric heating detection circuit for: after power-on initialization, turning on the electric heating and maintaining it for a preset time, and detecting whether the air conditioner is equipped with electric heating according to the level signal output by the electric heating detection circuit within the preset time; when it is detected that the air conditioner is equipped with electric heating, determining whether an air conditioner start command and an electric heating turn-on command sent by a wired controller are received; when the air conditioner start command and the electric heating turn-on command are received, not performing anti-cold wind control, controlling the air conditioner to enter a heating mode after startup, and controlling the indoor fan to start and run at a preset speed. The embodiment of the present invention can automatically detect whether the air conditioner is equipped with electric heating and select whether to perform anti-cold wind control according to the detection result to avoid potential safety hazards caused by too high surface temperature of the electric heating, thereby improving the reliability, safety, and user comfort of the air conditioner operation.

[0065] As an optional embodiment, the electric heating detection circuit includes a signal input module, an electric heating connection module, a rectification module, and a zero-crossing detection module;

[0066] The first input end of the signal input module is used to connect an AC power signal, the second input end of the signal input module is connected to the controller, and the output end of the signal input module is connected to the first end of the electric heating connection module;

[0067] The first end and the second end of the electric heating connection module are used to connect the electric heating, and the first end and the second end of the electric heating connection module are respectively connected to the first input end and the second input end of the rectification module;

[0068] The first output end and the second output end of the rectification module are respectively connected to the first input end and the second input end of the zero-crossing detection module;

[0069] The first output end of the zero-crossing detection module is connected to the controller, and the second output end of the zero-crossing detection module is grounded.

[0070] Combined with Figure 4As shown in the figure, it is a structural block diagram of an electric heating detection circuit provided by an embodiment of the present invention. In the embodiment of the present invention, the electric heating detection circuit mainly consists of a signal input module, an electric heating connection module, a rectification module, and a zero-crossing detection module, where:

[0071] The signal input module includes at least a first input terminal, a second input terminal, and an output terminal. The electric heating connection module includes at least a first terminal and a second terminal. The rectification module includes at least a first input terminal, a second input terminal, a first output terminal, and a second output terminal. The zero-crossing detection module includes at least a first input terminal, a second input terminal, a first output terminal, and a second output terminal;

[0072] Further, the first input terminal of the signal input module is used to connect to an AC power signal ( Figure 4 the AC signal shown in the figure) to obtain AC power. The second input terminal of the signal input module is connected to the controller. The output terminal of the signal input module is connected to the first terminal of the electric heating connection module. The first terminal and the second terminal of the electric heating connection module are used to connect to the electric heating. That is, if an electric heating is installed in the air conditioner, the electric heating will be installed on the electric heating connection module. At the same time, the first terminal of the electric heating connection module is connected to the first input terminal of the rectification module, and the second terminal of the electric heating connection module is connected to the second input terminal of the rectification module. The first output terminal of the rectification module is connected to the first input terminal of the zero-crossing detection module, and the second output terminal of the rectification module is connected to the second input terminal of the zero-crossing detection module. The first output terminal ( Figure 4 the ZERO terminal shown in the figure) of the zero-crossing detection module is connected to the controller, and the second output terminal of the zero-crossing detection module is grounded.

[0073] It should be noted that in the embodiment of the present invention, the AC power signal received by the signal input module can be a 24V AC signal input by the wire controller. Among them, the North American models are all market-standard wire controllers, and the main control board provides AC 24V power supply. Since the power supply of the wire controller is taken from the AC 24V of the indoor main control board, this AC 24V is inside the wire controller, and different command control signals (such as fan start, compressor start, etc.) are output through the control commands of the wire controller. And these commands are all based on the AC 24V power supply of the main control board. Therefore, the wire controller control signal outputs AC 24V. It can be thought that there is a row of relays inside the wire controller, and when the relay is closed, the command is output. The electric heating in the embodiment of the present invention can also be directly connected to the power supply pin of the wire controller, the same as the power supply of the main control board, only the connection position is different.

[0074] As an optional embodiment, the signal input module includes a relay. The two contact terminals of the relay are respectively connected to the first input terminal and the output terminal of the signal input module, and the two coil terminals of the relay are respectively connected to the second input terminal of the signal input module and the power supply.

[0075] Combined Figure 5 As shown, it is the schematic diagram of an electric heating detection circuit provided by an embodiment of the present invention. In the embodiment of the present invention, the signal input module mainly consists of a relay ( Figure 5 K shown). The relay K includes two contact terminals and two coil terminals. Among them, one contact terminal of the relay K is connected to the first input end of the signal input module for obtaining an AC signal, and the other contact terminal of the relay K is connected to the output end of the signal input module. One coil terminal of the relay K is connected to the second input end of the signal input module (i.e., connected to the controller), and the other coil terminal of the relay K is connected to a power supply (for example, a +12V power supply).

[0076] It should be noted that when the relay K receives an electric heating control signal of AC 24V, the relay K will be attracted and transfer the received AC signal to the subsequent circuit for further corresponding processing.

[0077] As one of the optional embodiments, the electric heating connection module includes an electric heating interface, and the two interface terminals of the electric heating interface are respectively connected to the first end and the second end of the electric heating connection module.

[0078] Combined Figure 5 As shown, in the embodiment of the present invention, the electric heating connection module mainly consists of an electric heating interface ( Figure 5 U shown). The electric heating interface U includes at least two interface terminals. Among them, one interface terminal of the electric heating interface is connected to the first end of the electric heating connection module, and the other interface terminal of the electric heating interface is connected to the second end of the electric heating connection module; it can be understood that if an electric heater is installed in the air conditioner, the connection terminals corresponding to the electric heater can be correspondingly connected to the interface terminals of the electric heating interface U.

[0079] As one of the optional embodiments, the zero-crossing detection module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, and a switching tube;

[0080] The first end of the first resistor is connected to the first input end of the zero-crossing detection module, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the second input end of the zero-crossing detection module;

[0081] The first end of the third resistor is connected to the power supply, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the first output end of the zero-crossing detection module;

[0082] The control terminal of the switching transistor is connected to the second terminal of the first resistor, the input terminal of the switching transistor is connected to the second terminal of the third resistor, and the output terminal of the switching transistor is connected to the second output terminal of the zero-crossing detection module;

[0083] The first terminal of the first capacitor is connected to the second terminal of the first resistor, and the second terminal of the first capacitor is connected to the second input terminal of the zero-crossing detection module;

[0084] The first terminal of the second capacitor is connected to the second terminal of the fourth resistor, the second terminal of the second capacitor is connected to the second output terminal of the zero-crossing detection module, and the second input terminal of the zero-crossing detection module is connected to the second output terminal of the zero-crossing detection module.

[0085] Combined Figure 5 As shown, in the embodiment of the present invention, the zero-crossing detection module mainly consists of a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, and a switching transistor Q; wherein, the first terminal of the first resistor R1 is connected to the first input terminal of the zero-crossing detection module, the second terminal of the first resistor R1 is connected to the first terminal of the second resistor R2, and the second terminal of the second resistor R2 is connected to the second input terminal of the zero-crossing detection module; the first terminal of the third resistor R3 is connected to a power supply (for example, a +5V power supply), the second terminal of the third resistor R3 is connected to the first terminal of the fourth resistor R4, and the second terminal of the fourth resistor R4 is connected to the first output terminal (i.e., the ZERO terminal) of the zero-crossing detection module; the control terminal of the switching transistor Q is connected to the second terminal of the first resistor R1, the input terminal of the switching transistor Q is connected to the second terminal of the third resistor R3, and the output terminal of the switching transistor Q is connected to the second output terminal of the zero-crossing detection module; the first terminal of the first capacitor C1 is connected to the second terminal of the first resistor R1, and the second terminal of the first capacitor C1 is connected to the second input terminal of the zero-crossing detection module; the first terminal of the second capacitor C2 is connected to the second terminal of the fourth resistor R4, and the second terminal of the second capacitor C2 is connected to the second output terminal of the zero-crossing detection module. Further, the second input terminal of the zero-crossing detection module is connected to the second output terminal of the zero-crossing detection module, and both are grounded.

[0086] It should be noted that in the embodiment of the present invention, the first capacitor C1 and the second capacitor C2 mainly play a filtering role in the electric heating detection circuit.

[0087] It should be noted that the switching transistor Q can be a triode as Figure 5 shown, or other types of switching devices such as MOSFETs and IGBTs, and the embodiment of the present invention does not make specific limitations.

[0088] Exemplarily, R1 = 10 kΩ, R2 = 10 kΩ, R3 = 10 kΩ, R4 = 1 kΩ, C1 = 100 nF, C2 = 4.7 nF.

[0089] It should be noted that, in combination with Figure 5 as shown, in the embodiment of the present invention, the rectification module can adopt a bridge rectification structure composed of 4 diodes, that is Figure 5 it can be implemented by the rectifier bridge VD as shown.

[0090] It should be noted that after the controller is powered on and initialized, it can determine whether an electric heater is installed in the air conditioner by forcibly starting the electric heater for a preset time. It can be understood that there is an AC 24V AC signal input at the first input terminal of the signal input module. At this time, the relay K is energized. If the air conditioner is equipped with an electric heater (that is, the electric heater connection module is connected to the electric heater), then the AC 24V electric heater control signal is transmitted to the electric heater connection module through the relay K and connected to the electric heater terminal, correspondingly forming a current loop; the AC signal is transmitted to the rectification module at the back end, and the rectification module converts the AC signal into a DC signal and transmits it to the zero-crossing detection module at the back end; the zero-crossing detection module outputs a low-level signal all the time under normal circumstances at the non-zero-crossing point of the AC signal according to the periodic change of the AC signal, and outputs a high-level signal at the zero-crossing point of the AC signal. In combination with Figure 6 as shown, it is a waveform diagram of an electric heater detection circuit provided by an embodiment of the present invention. Among them, Figure 6 the upper waveform diagram is the waveform diagram corresponding to the output voltage Ud of the rectifier bridge VD, Figure 6 the lower waveform diagram is the waveform diagram corresponding to the first output terminal of the zero-crossing detection module, that is, the ZERO terminal. According to Figure 6 it can be known that the ZERO terminal outputs a high-level signal at the zero-crossing point of the Ud signal and outputs a low-level signal at the non-zero-crossing point of the Ud signal; the ZERO terminal of the zero-crossing detection module is connected to the controller (for example, connected to the zero-crossing detection pin of the MCU), and the controller can judge whether the air conditioner is equipped with an electric heater according to the level signal output by the ZERO terminal of the zero-crossing detection module.

[0091] As one of the optional embodiments, the controller detects whether the air conditioner is equipped with an electric heater according to the level signal output by the electric heater detection circuit within the preset time, which specifically includes:

[0092] Detect whether the preset level change rule is satisfied according to the level signal output by the electric heater detection circuit within the preset time;

[0093] When the level change rule is satisfied, it is determined that the air conditioner is equipped with an electric heater;

[0094] When the level change rule is not satisfied, it is determined that the air conditioner is not equipped with an electric heater.

[0095] In combination with Figure 7As shown in the figure, it is a flowchart of the operation of a controller of an air conditioner provided by another embodiment of the present invention. On the basis of the above embodiment, in the specific implementation of the embodiment of the present invention, when the controller detects whether the air conditioner is equipped with electric heating according to the level signal output by the electric heating detection circuit within a preset time, it can detect whether the received level signal satisfies the preset level change rule according to the level signal output by the electric heating detection circuit within the preset time ( Figure 7 as shown in step S131); when the controller detects that the level signal output by the electric heating detection circuit within the preset time satisfies the preset level change rule, it determines that the air conditioner is equipped with electric heating ( Figure 7 as shown in step S132); when the controller detects that the level signal output by the electric heating detection circuit within the preset time does not satisfy the preset level change rule, it determines that the air conditioner is not equipped with electric heating ( Figure 7 as shown in step S133).

[0096] As one optional embodiment, the level change rule is: the level signal output by the electric heating detection circuit within the preset time includes n high-level pulses; where n≥2.

[0097] On the basis of the above embodiment, in the specific implementation of the embodiment of the present invention, the level change rule used as the judgment criterion can be preset as: the level signal output by the electric heating detection circuit within the preset time includes n high-level pulses; where n≥2. Correspondingly, if the controller detects that the level signal output by the electric heating detection circuit within the preset time includes n high-level pulses, it determines that the air conditioner is equipped with electric heating; if the controller detects that the level signal output by the electric heating detection circuit within the preset time does not include n high-level pulses, it determines that the air conditioner is not equipped with electric heating.

[0098] It should be noted that the value of n can be set according to actual needs, and the minimum is 2 (related to the length of the preset time and the actual working process of the electric heating detection circuit), and the embodiment of the present invention does not make specific limitations.

[0099] Exemplarily, assuming that the preset time = 500ms and n = 30, when the controller uses the level signal output by the ZERO terminal of the electric heating detection circuit to determine whether the air conditioner is equipped with electric heating, if it is detected that the number of high-level pulses with regular high and low level changes in the level signal within 500ms is 30, it means that the air conditioner is equipped with electric heating. If it is detected that the number of high-level pulses with regular high and low level changes in the level signal within 500ms is less than 30, or it is detected that the level signal within 500ms is always a high-level signal, it means that the air conditioner is not equipped with electric heating.

[0100] As one of the optional embodiments, the controller is further configured to:

[0101] When receiving the air conditioner startup command and not receiving the electric heating startup command, perform anti-cold wind control; wherein, the anti-cold wind control includes: controlling the air conditioner to enter the heating mode after startup, controlling the indoor fan not to start, and adjusting the operating speed of the indoor fan according to the indoor coil temperature until the preset speed is reached.

[0102] Combined with Figure 8 As shown, it is a working flowchart of a controller of an air conditioner provided by another embodiment of the present invention. On the basis of the above embodiment, in the specific implementation of the embodiment of the present invention, after the controller determines whether it has received the air conditioner startup command and the electric heating startup command sent by the remote controller, if the determination result is negative, it is further configured to determine whether it has received the air conditioner startup command sent by the remote controller, and has not received the electric heating startup command sent by the remote controller ( Figure 8 Step S16 shown), when the controller determines that it has received the air conditioner startup command sent by the remote controller and has not received the electric heating startup command sent by the remote controller, it determines that the air conditioner performs anti-cold wind control. At this time, the controller will control the air conditioner to start up according to the received air conditioner startup command, and control the air conditioner to enter the heating mode after startup. Further, the controller will control the indoor fan not to start, and adjust the actual operating speed of the indoor fan according to the indoor coil temperature until the speed of the indoor fan reaches the preset speed ( Figure 8 Step S17 shown).

[0103] It should be noted that when the controller adjusts the actual operating speed of the indoor fan according to the indoor coil temperature, it can gradually increase the speed of the indoor fan as the indoor coil temperature rises. For example, when the indoor coil temperature is 20 °C, the indoor fan can be controlled to operate at the minimum speed to blow out a gentle breeze; when the indoor coil temperature is 27 °C, the indoor fan can be controlled to operate at a relatively low speed to blow out a low wind; when the indoor coil temperature is 35 °C, the indoor fan can be controlled to operate at a medium speed to blow out a medium wind; when the indoor coil temperature is above 38 °C, the indoor fan can be controlled to operate at the preset speed (the speed is preset within EE).

[0104] As one of the optional embodiments, the controller is further configured to:

[0105] When detecting that the electric heating is not installed in the air conditioner, perform anti-cold wind control; wherein, the anti-cold wind control includes: controlling the air conditioner to enter the heating mode after startup, controlling the indoor fan not to start, and adjusting the operating speed of the indoor fan according to the indoor coil temperature until the preset speed is reached.

[0106] Combined withFigure 9 As shown, it is a working flowchart of a controller of an air conditioner provided by another embodiment of the present invention. On the basis of the above embodiment, when the present invention is specifically implemented, after the controller detects and determines whether an electric heater is installed in the air conditioner according to the level signal output by the electric heater detection circuit within a preset time, when the controller detects that no electric heater is installed in the air conditioner (for example, the controller detects that the level signal is always high), at this time, regardless of whether the controller receives an electric heater turn-on command sent by the remote controller (but receives an air conditioner turn-on command), the controller will execute the anti-cold wind function according to the software, that is, determine that the air conditioner executes anti-cold wind control. At this time, the controller will control the air conditioner to turn on according to the received air conditioner turn-on command, and control the air conditioner to enter the heating mode after turning on. Further, the controller will control the indoor fan not to start, and adjust the actual operating speed of the indoor fan according to the indoor coil temperature until the speed of the indoor fan reaches the preset speed ( Figure 9 as shown in step S18).

[0107] The embodiment of the present invention also provides a control method for an air conditioner. Refer to Figure 10 As shown, it is a schematic flowchart of a control method for an air conditioner provided by an embodiment of the present invention. The method is applicable to the air conditioner described in any of the above embodiments. The method is executed by the controller, and the method includes steps S101 to S103:

[0108] Step S101: After power-on initialization, turn on the electric heater and keep it for a preset time, and detect whether the air conditioner is installed with an electric heater according to the level signal output by the electric heater detection circuit within the preset time;

[0109] Step S102: When it is detected that the air conditioner is installed with an electric heater, determine whether an air conditioner turn-on command and an electric heater turn-on command sent by the remote controller are received;

[0110] Step S103: When the air conditioner turn-on command and the electric heater turn-on command are received, do not execute the anti-cold wind control, control the air conditioner to enter the heating mode after turning on, and control the indoor fan to start and operate at a preset speed.

[0111] In some embodiments, the electric heater detection circuit includes a signal input module, an electric heater connection module, a rectification module, and a zero-crossing detection module;

[0112] The first input end of the signal input module is used to connect an AC power signal, the second input end of the signal input module is connected to the controller, and the output end of the signal input module is connected to the first end of the electric heater connection module;

[0113] The first end and the second end of the electric heating connection module are used to connect to the electric heating, and the first end and the second end of the electric heating connection module are respectively connected to the first input end and the second input end of the rectification module;

[0114] The first output end and the second output end of the rectification module are respectively connected to the first input end and the second input end of the zero-crossing detection module;

[0115] The first output end of the zero-crossing detection module is connected to the controller, and the second output end of the zero-crossing detection module is grounded.

[0116] In some embodiments, the signal input module includes a relay. The two contact terminals of the relay are respectively connected to the first input end and the output end of the signal input module, and the two coil terminals of the relay are respectively connected to the second input end of the signal input module and the power supply.

[0117] In some embodiments, the electric heating connection module includes an electric heating interface. The two interface terminals of the electric heating interface are respectively connected to the first end and the second end of the electric heating connection module.

[0118] In some embodiments, the zero-crossing detection module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor and a switching tube;

[0119] The first end of the first resistor is connected to the first input end of the zero-crossing detection module, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the second input end of the zero-crossing detection module;

[0120] The first end of the third resistor is connected to the power supply, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the first output end of the zero-crossing detection module;

[0121] The control end of the switching tube is connected to the second end of the first resistor, the input end of the switching tube is connected to the second end of the third resistor, and the output end of the switching tube is connected to the second output end of the zero-crossing detection module;

[0122] The first end of the first capacitor is connected to the second end of the first resistor, and the second end of the first capacitor is connected to the second input end of the zero-crossing detection module;

[0123] The first end of the second capacitor is connected to the second end of the fourth resistor, the second end of the second capacitor is connected to the second output end of the zero-crossing detection module, and the second input end of the zero-crossing detection module is connected to the second output end of the zero-crossing detection module.

[0124] In some embodiments, detecting whether the air conditioner is equipped with electric heating according to the level signal output by the electric heating detection circuit within the preset time specifically includes:

[0125] According to the level signal output by the electric heating detection circuit within the preset time, detecting whether it meets a preset level change rule;

[0126] When the level change rule is met, determining that the air conditioner is equipped with electric heating;

[0127] When the level change rule is not met, determining that the air conditioner is not equipped with electric heating.

[0128] In some embodiments, the level change rule is: the level signal output by the electric heating detection circuit within the preset time includes n high-level pulses; where n≥2.

[0129] In some embodiments, the method further includes:

[0130] When receiving the air conditioner startup command and not receiving the electric heating startup command, performing anti-cold wind control; where the anti-cold wind control includes: controlling the air conditioner to enter the heating mode after startup, controlling the indoor fan not to start, and adjusting the running speed of the indoor fan according to the indoor coil temperature until the preset speed is reached.

[0131] In some embodiments, the method further includes:

[0132] When detecting that the air conditioner is not equipped with electric heating, performing anti-cold wind control; where the anti-cold wind control includes: controlling the air conditioner to enter the heating mode after startup, controlling the indoor fan not to start, and adjusting the running speed of the indoor fan according to the indoor coil temperature until the preset speed is reached.

[0133] It should be noted that a control method for an air conditioner provided in an embodiment of the present invention can implement all the working processes of the air conditioner described in any of the above embodiments. The specific implementation schemes corresponding to the control method and the achieved technical effects are respectively the same as the specific implementation schemes and the achieved technical effects of the air conditioner described in the above embodiments, and will not be elaborated here.

[0134] In summary, an air conditioner and a control method thereof provided by an embodiment of the present invention, the air conditioner includes: a refrigerant circuit in which refrigerant circulates in a freezing cycle through a compressor, a condenser, a throttling component, and an evaporator in sequence, one of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger; an indoor fan for blowing the air after heat exchange by the indoor heat exchanger into the room; an electric heating detection circuit for connecting to the electric heating and outputting a level signal when powered on; a controller connected to the electric heating detection circuit for: after power-on initialization, turning on the electric heating and lasting for a preset time, detecting whether the air conditioner is equipped with electric heating according to the level signal output by the electric heating detection circuit within the preset time; when it is detected that the air conditioner is equipped with electric heating, judging whether an air conditioner startup command and an electric heating turn-on command sent by a wired controller are received; when the air conditioner startup command and the electric heating turn-on command are received, not performing anti-cold wind control, controlling the air conditioner to enter a heating mode after startup, and controlling the indoor fan to start and operate at a preset speed. The embodiment of the present invention can automatically detect whether the air conditioner is equipped with electric heating, and select whether to perform anti-cold wind control according to the detection result, so as to avoid potential safety hazards caused by too high surface temperature of the electric heating, thereby improving the reliability, safety, and user comfort of the air conditioner operation.

[0135] The above are only some embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can still be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. An air conditioner, characterized in that, The air conditioner includes: A refrigerant circuit in which refrigerant circulates in sequence through a compressor, a condenser, a throttling component, and an evaporator in a refrigeration cycle, and one of the condenser and the evaporator is an outdoor heat exchanger, and the other is an indoor heat exchanger; An indoor fan for blowing the air after heat exchange by the indoor heat exchanger into the room; An electric heating detection circuit for connecting to the electric heating and outputting a level signal when powered on; A controller connected to the electric heating detection circuit for: After power-on initialization, turn on the electric heating and continue for a preset time, and detect whether the air conditioner is equipped with electric heating according to the level signal output by the electric heating detection circuit within the preset time; When it is detected that the air conditioner is equipped with electric heating, determine whether an air conditioner startup command and an electric heating startup command sent by the remote controller are received; When the air conditioner startup command and the electric heating startup command are received, do not execute the anti-cold wind control, control the air conditioner to enter the heating mode after startup, and control the indoor fan to start and operate at a preset speed.

2. The air conditioner according to claim 1, characterized in that, The electric heating detection circuit includes a signal input module, an electric heating connection module, a rectification module, and a zero-crossing detection module; The first input terminal of the signal input module is used to connect to an AC power signal, the second input terminal of the signal input module is connected to the controller, and the output terminal of the signal input module is connected to the first end of the electric heating connection module; The first end and the second end of the electric heating connection module are used to connect to the electric heating, and the first end and the second end of the electric heating connection module are respectively connected to the first input terminal and the second input terminal of the rectification module; The first output terminal and the second output terminal of the rectification module are respectively connected to the first input terminal and the second input terminal of the zero-crossing detection module; The first output terminal of the zero-crossing detection module is connected to the controller, and the second output terminal of the zero-crossing detection module is grounded.

3. The air conditioner according to claim 2, wherein The signal input module includes a relay, and two contact terminals of the relay are respectively connected to the first input terminal and the output terminal of the signal input module, and two coil terminals of the relay are respectively connected to the second input terminal of the signal input module and the power supply; 4. The air conditioner according to claim 2, wherein, The electric heating connection module includes an electric heating interface, and two interface terminals of the electric heating interface are respectively connected to the first end and the second end of the electric heating connection module; 5. The air conditioner according to claim 2, wherein The zero-crossing detection module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, and a switching tube; The first end of the first resistor is connected to the first input terminal of the zero-crossing detection module, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the second input terminal of the zero-crossing detection module; The first end of the third resistor is connected to the power supply, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the first output terminal of the zero-crossing detection module; The control terminal of the switching transistor is connected to the second terminal of the first resistor, the input terminal of the switching transistor is connected to the second terminal of the third resistor, and the output terminal of the switching transistor is connected to the second output terminal of the zero-crossing detection module; The first terminal of the first capacitor is connected to the second terminal of the first resistor, and the second terminal of the first capacitor is connected to the second input terminal of the zero-crossing detection module; The first terminal of the second capacitor is connected to the second terminal of the fourth resistor, the second terminal of the second capacitor is connected to the second output terminal of the zero-crossing detection module, and the second input terminal of the zero-crossing detection module is connected to the second output terminal of the zero-crossing detection module.

6. The air conditioner according to claim 1, wherein, The controller detects whether the air conditioner is equipped with electric heating according to the level signal output by the electric heating detection circuit within the preset time, specifically including: Detecting whether the preset level change rule is satisfied according to the level signal output by the electric heating detection circuit within the preset time; When the level change rule is satisfied, it is determined that the air conditioner is equipped with electric heating; When the level change rule is not satisfied, it is determined that the air conditioner is not equipped with electric heating.

7. The air conditioner according to claim 6, characterized in that The level change rule is that the level signal output by the electric heating detection circuit within the preset time includes n high-level pulses; where n≥2.

8. The air conditioner according to claim 1, characterized in that, The controller is further configured to: When receiving the air conditioner startup command and not receiving the electric heating startup command, perform anti-cold wind control; where the anti-cold wind control includes: controlling the air conditioner to enter the heating mode after startup, controlling the indoor fan not to start, and adjusting the operating speed of the indoor fan according to the indoor coil temperature until the preset speed is reached.

9. The air conditioner according to any one of claims 1 to 8, characterized in that, The controller is further configured to: When detecting that the air conditioner is not equipped with electric heating, perform anti-cold wind control; where the anti-cold wind control includes: controlling the air conditioner to enter the heating mode after startup, controlling the indoor fan not to start, and adjusting the operating speed of the indoor fan according to the indoor coil temperature until the preset speed is reached.

10. A control method for an air conditioner, characterized in that, Applicable to the air conditioner according to any one of claims 1 to 9, the method is executed by the controller, and the method includes: After power-on initialization, turn on the electric heating and continue for a preset time, and detect whether the air conditioner is equipped with electric heating according to the level signal output by the electric heating detection circuit within the preset time; When detecting that the air conditioner is equipped with electric heating, determine whether the air conditioner startup command and the electric heating startup command sent by the wired controller are received; When receiving the air conditioner startup command and the electric heating startup command, do not perform anti-cold wind control, control the air conditioner to enter the heating mode after startup, and control the indoor fan to start and operate at the preset speed.

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