WO2019100774A1

WO2019100774A1 - Electric heater protection method and device, and air conditioner

Info

Publication number: WO2019100774A1
Application number: PCT/CN2018/100952
Authority: WO
Inventors: 梁尤轩; 沈军; 赵桓; 罗祖分
Original assignee: 格力电器（武汉）有限公司; 珠海格力电器股份有限公司
Priority date: 2017-11-23
Filing date: 2018-08-17
Publication date: 2019-05-31
Also published as: CN108180595A; CN108180595B

Abstract

An electric heater protection method and device, and an air conditioner. The device comprises an air exit temperature collection unit and a control unit. The air exit temperature collection unit collects an air exit temperature of an air conditioner having electric heaters (3, 4) and operating in a heating mode. The control unit determines, according to the air exit temperature, whether dry burning occurs in the electric heaters (3, 4), and controls an inner air blower of the air conditioner to operate in a preset state upon occurrence of dry burning.

Description

Electric heater protection method, device and air conditioner

This application claims the priority of the Chinese Patent Application filed on November 23, 2017, the Chinese Patent Application No. 201711221573.7, entitled "Electrical Heater Protection Method, Apparatus, and Air Conditioning", the entire contents of which are incorporated by reference. In this application.

Technical field

The present invention relates to the field of circuits, and in particular, to an electric heater protection method and apparatus, and an air conditioner having the same.

Background technique

At present, household appliances such as air conditioners, humidifiers, and electric heaters generally use electric heaters with auxiliary heating functions for heating. Under normal circumstances, the auxiliary electric heating PTC control of the air conditioning unit adopts an open loop control mode. However, when an abnormal situation occurs, the air conditioner cannot judge the state of the electric heating switch. The PTC dry burning may cause the temperature of the surrounding material to rise, which may cause overheating deformation of the whole household appliance, and may cause a safety accident such as a fire caused by spontaneous combustion of the sponge material. If you work in dry burn for a long time, there may be PTC accelerated attenuation, insulation failure, and short circuit caused by PTC chip breakdown.

There are many ideas for the control method using auxiliary electric heating anti-drying. For example, CN105357780A passes the current detection, CN102954556B passes the voltage detection, and CN201697275U uses the temperature limiter and the main circuit fuse to judge. However, the circuit needs to detect the current or voltage of the air conditioner PTC, which requires additional circuits and increases the controller cost. For the air conditioner installed on the electric bus, the manufacturer has no mature high voltage because of the high operating voltage of the air conditioner (above DC450V). Fuse, and the new fuse development cycle is also relatively long.

Summary of the invention

In view of this, the object of the present invention is to provide a low-cost electric heater protection circuit and a protection method to avoid the occurrence of PTC dry burning and enhance the safety of air conditioning use.

According to a first aspect of the present invention, an electric heater protection device is provided, comprising: an air outlet temperature collecting unit and a control unit; wherein the air outlet temperature collecting unit is configured to collect the electric heater The air outlet temperature of the air conditioner when operating in the heating mode; the control unit is configured to determine whether the electric heater is dry-fired according to the outlet air temperature, and if the electric heater is dry-burned, control the air conditioner The fan works according to the predetermined state.

Further, the method further includes: an electric heater temperature alarm unit, wherein the electric heater temperature alarm unit is configured to detect the electric heater temperature, and if the detected electric heater temperature is greater than the electric heater temperature alarm threshold, the electric heater temperature alarm The unit reports a fault; the control unit is further configured to determine whether the electric heater is dry-fired according to whether the air outlet temperature and the electric heater temperature alarm unit report a fault.

Further, the method further includes: a first contactor switch connected to the first end of the electric heater; and a second contactor switch connected to the second end of the electric heater.

Further, the control unit determines whether the electric heater is dry-burned, including: opening the first contactor switch; turning off the electric heater; determining that the first interval elapsed after the electric heater is turned off is greater than a setting When the first time threshold is reached, the electric heater temperature alarm unit reports a fault, and if so, it is determined that the electric heater is dry, and the first contactor switch is determined to be faulty.

Further, the control unit determines whether the electric heater is dry or not, and further includes: determining whether the electric heater temperature alarm unit reports a fault when the first interval time is greater than the first time threshold, and if the result is no, determining When the second interval time elapsed from determining whether the electric heater temperature alarm unit has reported failure when the first interval time is greater than the first time threshold is greater than a set second time threshold, the exhaust air temperature collecting unit detects Whether the outlet air temperature is greater than a set first temperature threshold, and if so, it is determined that the electric heater is dry and the first contactor switch is faulty.

Further, the control unit determines whether the electric heater is dry or not, and further includes: determining whether the air outlet temperature detected by the air outlet temperature collecting unit is greater than one when the second interval time is greater than the second time threshold The first temperature threshold, if the result is no, perform the following operations: turn off the internal fan; determine that the third interval time that is elapsed since the internal fan is turned off is greater than a set third time threshold, the exhaust air temperature is collected Whether the air temperature detected by the unit is greater than a set second temperature threshold; if yes, it is determined that the electric heater is dry and the first contactor switch is faulty; if not, it is determined that the electric heater is normally turned off, and the first The contactor switch is normal.

Further, the control unit determines whether the electric heater is dry burned, and further includes: if it is determined that the electric heater is dry and the first contactor switch is faulty, further performing the following operation: disconnecting the second contactor a switch; determining whether an air outlet temperature detected by the air outlet temperature collecting unit is greater than a set third when a fourth interval time elapsed since the second contactor switch is turned off is greater than a set fourth time threshold Temperature threshold; if yes, it is determined that the electric heater is dry, and the first contactor switch and the second contactor switch are faulty; if not, it is judged that the electric heater is dry, the first contactor switch is faulty, and the second contact The switch is normal.

Further, the control unit determines whether the electric heater is dry or not, and further includes: if the electric heater is dry, the first and second contactor switches are faulty, and the control unit controls the inner fan to be in the first state during standby State; and/or, if the electric heater is dry, the first contactor switch is faulty, the second contactor switch is normal, the control unit controls the inner fan to be in the second state during standby; and/or if the electric heater is normal When the first contactor switch is turned off and the first contactor switch is normal, the control unit controls the internal fan to be in the third state during standby.

Further, in the first state, the inner fan is turned on according to the middle wind; and/or the inner fan is turned off in the second state; and/or the inner fan is turned off in the third state.

Further, the electric heater temperature alarm threshold ranges from 150 to 250 °C.

Further, the first time threshold ranges from 1 to 10 minutes; and/or the second time threshold ranges from 1 to 10 minutes; and/or the third time threshold ranges from 1 to 10 minutes; and/or, the fourth time threshold ranges from 5 to 10 minutes; and/or, the first temperature threshold ranges from 50 to 70 ° C; and/or the value of the second time threshold The range is 50-70 ° C; and / or, the third time threshold ranges from 50-70 ° C.

Further, the fault prompting unit is further configured to issue a prompt under the control of the control unit when the control unit determines that the electric heater is dry.

Further, the fault prompting unit is selected from one or more of a display unit, a speaker, and an indicator light, and issues a prompt in the form of text, image, voice, buzzer, and/or flashing light.

According to a second aspect of the present invention, there is provided a method of protecting an electric heater, comprising: collecting an air outlet temperature of an air conditioner to which the electric heater belongs in a heating mode; The temperature determines whether the electric heater is dry-fired, and if the electric heater is dry-fired, the inner fan that controls the air conditioner operates according to a predetermined state.

Further, the method further includes the steps of: detecting the electric heater temperature, and if the detected electric heater temperature is greater than the electric heater temperature alarm threshold, using an electric heater temperature alarm unit to report a fault; according to the outlet air temperature and electric heating Whether the temperature alarm unit reports a fault determines whether the electric heater has dry burned.

Further, the method further includes the steps of: connecting the first contactor switch to the first end of the electric heater; and connecting the second contactor switch to the second end of the electric heater.

Further, the determining whether the electric heater is dry or not is specifically: disconnecting the first contactor switch; turning off the electric heater; determining that the first interval time elapsed since the electric heater is turned off is greater than a set At the first time threshold, the electric heater temperature alarm unit reports a fault, and if so, it is determined that the electric heater is dry, and the first contactor switch is determined to be faulty.

Further, the determining whether the electric heater is dry or not further comprises the steps of: determining whether the electric heater temperature alarm unit reports a fault when the first interval time is greater than the first time threshold, and if the result is no, Determining whether the exit air temperature is greater than a setting when determining that the second interval time elapsed after the electric heater temperature alarm unit reports the fault is greater than a set second time threshold when the first interval time is greater than the first time threshold The first temperature threshold, if so, determines that the electric heater is dry and the first contactor switch is faulty.

Further, the determining whether the electric heater is dry or not further comprises the following steps: determining whether the air outlet temperature is greater than a first temperature threshold when the second interval time is greater than the second time threshold, if the result is No, the following operation is performed: closing the internal fan; determining whether the exit air temperature is greater than a set second temperature threshold when the third interval time elapsed since the closing of the inner fan is greater than a set third time threshold; If yes, it is judged that the electric heater is dry and the first contactor switch is faulty; if not, it is judged that the electric heater is normally turned off, and the first contactor switch is normal.

Further, the determining whether the electric heater is dry or not further comprises the following steps: if it is determined that the electric heater is dry and the first contactor switch is faulty, further performing the following operation: disconnecting the second contact And determining whether the exit air temperature is greater than a set third temperature threshold when the fourth interval time elapsed since the second contactor switch is turned off is greater than a set fourth time threshold; if yes, the determination occurs The electric heater is dry and the first contactor switch and the second contactor switch are faulty; if not, it is judged that the electric heater is dry, the first contactor switch is faulty, and the second contactor switch is normal.

Further, the determining whether the electric heater is dry or not further comprises: if the electric heater is dry, the first and second contactor switches are faulty, and the control inner fan is in the first state when in standby; and Or, if the electric heater is dry, the first contactor switch is faulty, the second contactor switch is normal, the control inner fan is in the second state during standby; and/or, if the electric heater is normally closed, and the first contact The switch is normal, and the control internal fan is in the third state during standby.

Further, when the electric heater is dry-fired, a prompt is issued by the fault prompting unit.

According to a third aspect of the invention, there is provided an air conditioner comprising: an electric heater; an inner fan; an electric heater protection device, wherein the electric heater protection device is the aforementioned electric heater protection device.

According to a fourth aspect of the present invention, there is provided a computer readable storage medium having stored thereon a computer program, the program being implemented by a processor to implement the steps of the foregoing method.

According to a fifth aspect of the present invention, an air conditioner is provided, comprising: a processor, a memory, and a computer program stored on the memory and operable on the processor, the processor implementing the program to implement the foregoing method step.

Through the above scheme, the invention determines whether the PTC is dry, determines whether the PTC contactor is stuck, and avoids the PTC dry burning by the internal fan control, thereby improving the reliability of the PTC, effectively avoiding the PTC dry burning situation, and enhancing the air conditioning use. Safety, on the other hand, also effectively reduces the cost of anti-PTC dry burning control.

The above description is only an overview of the technical solutions of the present invention, and the technical means of the present invention can be more clearly understood and can be implemented in accordance with the contents of the specification. Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

DRAWINGS

The accompanying drawings, which are incorporated in the claims In the drawing:

1 is an electric heater protection circuit in accordance with an embodiment of the present invention.

2 is a flow chart of a method of protecting an electric heater in accordance with an embodiment of the present invention.

Detailed ways

The technical solutions of the present invention will be clearly and completely described in conjunction with the specific embodiments of the present invention and the accompanying drawings. It is apparent that the described embodiments are only a part of the embodiments of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

1 is an electric heater protection circuit in accordance with the present invention. In the figure, reference numeral 1 is a contactor switch A, 2 is a contactor switch B, 3 is an electric heater PTC1, 4 is an electric heater PTC2, 5 is a temperature limiter L1, and 6 is a temperature limiter L2, 7 is The outlet air temperature T1,8 is the outlet air temperature T2.

This embodiment provides a PTC electric heater anti-dry protection circuit. The protection circuit is used in heating household appliances (such as air conditioners, heaters, etc.), and can timely determine whether the PTC electric heater in the household appliance has dry burn, and protect the PTC electric heater that has a dry burn fault.

As shown in FIG. 1 , the anti-dry protection circuit includes two electric heaters PTC1 and PTC2 connected in parallel, a contactor switch A, and a first end of the electric heaters PTC1 and PTC2, a contactor switch B, and an electric device. The second ends of the heaters PTC1 and PTC2 are connected. A thermostat L1 is mounted on the electric heater PTC1, and a thermostat L2 is mounted on the surface of the PTC2 for sensing the temperature T3 of the electric heater PTC1 for sensing electric heating. The temperature T4 of the PTC 2, the temperature limiters L1, L2 and the sensed temperatures T3, T4 are sent to a control unit (not shown in Fig. 1), such as an MCU of an air conditioner. If the temperature of the electric heater PTC1, and/or the electric heater PTC2 is found, ie T3 and/or T4 exceeds a predetermined threshold, the temperature limiter reports a fault. In the vicinity of the electric heater PTC1 and the electric heater PTC2, an outlet air temperature sensor (ie, an outlet temperature sensor) is further provided for detecting the outlet air temperatures T1 and T2 of the electric heaters PTC1 and PTC2, and the outlet air The temperature sensors respectively transmit the detected air outlet temperatures T1 and T2 to the control unit, and the control unit comprehensively determines the electric heating according to the fault report information sent by the air outlet temperature T1, T2, the temperature limiter L1, and the temperature limiter L2. Whether the PTC1 and PTC2 are abnormally closed, and whether the contactor switches A and B are stuck. The anti-dry protection circuit may further include a fault prompting unit to make a humidity sensor fault alarm reminder. The alarm prompt may be on a display (the display here may be a heating home appliance, such as a display unit on an air conditioner host, a display unit on a remote controller, or a display on a PTC anti-dry protection control device) Display dry burn fault information (such as corresponding fault code), and / or control the corresponding fault prompt unit to issue an alarm (for example, the buzzer beeps, the flashing light flashes) and other sounds, text, images, LEDs The mode will feedback the dry burning fault to the user in time, so that the user can repair in time to improve the safety and reliability of the product.

2 is a PTC electric heater anti-dry protection method according to an embodiment of the present invention. Taking a household air conditioner as an example, the method includes the following steps:

S201, executing a PTC shutdown command, and disconnecting one of the contactor switches A and B.

The choice of disconnecting the contactor switch A or B in this step is no different from the method itself, except that the order in which the two contactor switches are stuck is different. If you choose to disconnect contactor switch A this time, disconnect contactor switch B after receiving the electric heater off command next time. In this embodiment, the contactor switch A is selected to be disconnected first.

S202, heating shutdown.

After the heating shutdown, it is judged whether the electric heaters PTC1 and PTC2 have dry burning, whether the contactor switches A and B are stuck, and the inner fan is controlled according to the judgment result to avoid the PTC dry burning. Specifically:

S203, setting a time elapsed from the turning off of the electric heaters PTC1 and PTC2 to Time1, determining whether the temperature limiter L1, and/or the temperature limiter L2 reports a failure when Time1 is greater than a first time threshold n1, and if so, executing Step S204. Wherein, when the temperature of the electric heater PTC1 and/or the electric heater PTC2 detected by the temperature limiter L1 and/or the temperature limiter L2 exceeds a predetermined temperature limiter threshold, the temperature limiter reports PTC malfunction.

S204, the control unit determines, according to the above information, that the electric heater PTC1 and/or PTC2 is abnormally closed, and the contactor switch A is stuck. The contactor switch B is further turned off, and then step S205 is performed.

S205, setting a time elapsed from the disconnection of the contactor switch B to Time4, determining whether the exit air temperature T1, and/or the exit air temperature T2 is greater than a third temperature threshold c when Time4 is greater than a fourth time threshold n4, if If yes, go to step S206, if no, go to step S207.

At S206, it is judged that the electric heater PTC1 and/or the electric heater PTC2 are abnormally closed, and the contactor switches A and B are all stuck. The control unit further performs anti-dry protection to control the inner fan to be in the first state during standby. In the first state, the inner fan is opened according to the middle wind speed.

At S207, it is judged that the electric heater PTC1 and/or the electric heater PTC2 are abnormally closed, the contactor switch A is stuck, and the contactor switch B is in a normal state. At this time, the control unit controls the inner fan to be in the second state during standby. In the second state, the inner fan does not need to be turned on when it is in standby.

The above embodiment is performed on the premise that the temperature limiters L1 and L2 are working normally. If the temperature limiters L1 and L2 fail, the above judgment process is prone to leakage judgment, and there is also a safety hazard. Therefore, in the above embodiment, Based on this, a more preferred embodiment of the invention is further proposed:

In step S203, it is determined whether Time1 is greater than a first time threshold n1, and whether the temperature limiter L1, and/or the temperature limiter L2 reports a failure, and if not, step S208 is performed.

S208, when it is determined that Time1 is greater than a first time threshold n1, whether the temperature limiter L1, and/or the temperature limiter L2 reports a fault as a starting point, the elapsed time is Time2, and the Time2 is greater than a second time. When the threshold value n2, the outlet air temperature T1, and / or the outlet air temperature T2 is greater than the first temperature threshold a, if yes, step S204 is performed, if not, step S209 is performed;

S209, the air conditioner unit is controlled to enter a standby state, and the control unit controls the inner fan to be in a third state during standby. In the third state, the inner fan does not need to be turned on when it is in standby.

S210, setting a time elapsed from the time when the air conditioning unit enters the shutdown standby state in step S209 is Time3, and determining whether the air outlet temperature T1 and/or the outlet air temperature T2 is greater than a second temperature threshold when Time3 is greater than a third time threshold n3. b, if yes, go to step S204, if no, go to step S211.

At S211, it is judged that the electric heater PTC1/PTC2 is normally turned off, and the contactor switch A is normal. The contactor switch B is further disconnected, and the inner fan is controlled to be in the fourth state during standby. In the fourth state, the inner fan does not need to be turned on when it is in standby.

Therefore, the protection circuit detects the PTC air outlet temperature through the temperature limiter and the system temperature sensing package to determine whether the PTC is dry and the contactor switch is stuck. If it is determined that the PTC is dry, the control circuit controls the air blow by the internal fan. Reduce the PTC dry burning temperature, avoid accidents, and remind the user to repair the equipment through the fault prompt.

Preferably, the first time threshold n1 in the embodiment ranges from 1 to 10 minutes, the second time threshold n2 ranges from 1 to 10 minutes, and the third time threshold n3 ranges from 1 to 10. The value of the fourth time threshold a4 ranges from 5 to 10 minutes, the value of the first temperature threshold a ranges from 50 to 70 ° C, and the second time threshold b ranges from 50 to 70 ° C. The three-time threshold c ranges from 50 to 70 °C. The temperature limiter threshold ranges from 150 to 250 °C.

Through the above solution, the invention can detect the dry burning fault in time, avoid the abnormal high temperature caused by dry burning and the PTC overheating breakdown short circuit problem, and feed back the fault to the user, thereby improving the reliability of the PTC and effectively avoiding the PTC dry burning situation. To enhance the safety of air conditioning use.

Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, by hardware, but in many cases, the former is A better implementation. Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, may be embodied in the form of a software product stored in a storage medium (such as ROM/RAM, disk, The optical disc includes a number of instructions for causing a terminal device (which may be a cell phone, a computer, a server, or a network device, etc.) to perform the methods described in various embodiments of the present invention.

It should be noted that the embodiments in the present invention and the features in the embodiments may be combined with each other without conflict.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes and modifications made to the above embodiments in accordance with the technical spirit of the present invention are still in the present invention. Within the scope of the inventive solution.

Claims

An electric heater protection device, comprising:

An outlet temperature collecting unit and a control unit;

Wherein, the outlet air temperature collecting unit is configured to collect an air outlet temperature of the air conditioner to which the electric heater belongs in the heating mode;

The control unit is configured to determine whether the electric heater is dry-fired according to the outlet air temperature, and if the electric heater is dry-fired, controlling the inner fan of the air conditioner to operate according to a predetermined state.
The apparatus of claim 1 further comprising:

An electric heater temperature alarm unit, wherein the electric heater temperature alarm unit is configured to detect the electric heater temperature, and if the detected electric heater temperature is greater than the electric heater temperature alarm threshold, the electric heater temperature alarm unit reports a fault;

The control unit is further configured to determine whether the electric heater is dry burned according to whether the air outlet temperature and the electric heater temperature alarm unit report a fault.
The apparatus of claim 1 or 2, further comprising:

a first contactor switch connected to the first end of the electric heater;

A second contactor switch is coupled to the second end of the electric heater.
The apparatus according to claim 3, wherein said control unit determines whether said electric heater has dry burned comprises:

Disconnecting the first contactor switch;

Turn off the electric heater;

Determining whether the electric heater temperature alarm unit reports a fault when the first interval time elapsed since the electric heater is turned off is greater than a set first time threshold, and if so, determining that the electric heater is dry, and determining the number A contactor switch has failed.
The apparatus according to claim 4, wherein the control unit determines whether the electric heater has dry burned, and further includes:

Determining whether the electric heater temperature alarm unit reports a fault when the first interval time is greater than the first time threshold, and if the result is no, determining whether the electric heater temperature alarm unit is determined when the first interval time is greater than the first time threshold When the second interval time when the fault is started is greater than a set second time threshold, whether the air outlet temperature detected by the air outlet temperature collecting unit is greater than a set first temperature threshold, and if yes, determining that the power is generated The heater is dry and the first contactor switch is faulty.
The apparatus according to claim 5, wherein the control unit determines whether the electric heater has a dry burn, and further includes:

The determining whether the air outlet temperature detected by the air outlet temperature collecting unit is greater than a first temperature threshold when the second interval time is greater than the second time threshold, and if the result is no, performing the following operations:

Close the inner fan;

Determining whether the air outlet temperature detected by the air outlet temperature collecting unit is greater than a set second temperature threshold when the third interval time elapsed since the closing of the inner fan is greater than a set third time threshold;

If yes, it is judged that the electric heater is dry and the first contactor switch is faulty; if not, it is judged that the electric heater is normally turned off, and the first contactor switch is normal.
The apparatus according to any one of claims 4 to 6, wherein the control unit determines whether the electric heater has a dry burn, and further includes:

If it is determined that the electric heater is dry and the first contactor switch is faulty, further perform the following operations:

Disconnecting the second contactor switch;

Determining whether the air outlet temperature detected by the air outlet temperature collecting unit is greater than a set third temperature threshold when the fourth interval time elapsed since the second contactor switch is turned off is greater than a set fourth time threshold ;

If yes, it is judged that the electric heater is dry and the first contactor switch and the second contactor switch are faulty; if not, it is judged that the electric heater is dry, the first contactor switch is faulty, and the second contactor switch is normal. .
The apparatus according to any one of claims 3 to 7, wherein the control unit determines whether the electric heater has a dry burn, and further includes:

If the electric heater is dry, the first and second contactor switches are faulty, and the control unit controls the inner fan to be in the first state during standby;

And/or, if the electric heater is dry, the first contactor switch is faulty, the second contactor switch is normal, and the control unit controls the inner fan to be in the second state during standby;

And/or, if the electric heater is normally turned off and the first contactor switch is normal, the control unit controls the internal fan to be in the third state during standby.
The device of claim 8 wherein

In the first state, the inner fan is opened according to the middle wind speed;

And/or, in the second state, the inner fan is turned off;

And/or, the fan is turned off in the third state.
The apparatus according to any one of claims 2-9, wherein the electric heater temperature alarm threshold has a value ranging from 150 to 250 °C.
A device according to any of claims 4-10, wherein

The first time threshold ranges from 1 to 10 minutes;

And/or, the second time threshold ranges from 1 to 10 minutes;

And/or, the third time threshold ranges from 1 to 10 minutes;

And/or, the fourth time threshold ranges from 5 to 10 minutes;

And/or, the first temperature threshold ranges from 50 to 70 ° C;

And/or, the second time threshold ranges from 50 to 70 ° C;

And/or, the third time threshold ranges from 50 to 70 °C.
The apparatus according to any one of claims 1 to 11, further comprising a fault prompting unit for issuing a prompt under the control of the control unit when the control unit determines that the electric heater is dry burning.
The device according to claim 12, wherein the fault prompting unit is selected from one or more of a display unit, a speaker, and an indicator light, and prompts in the form of text, image, voice, buzzer, and/or flashing light. .
An electric heater protection method, comprising the steps of:

Collecting an outlet air temperature of the air conditioner to which the electric heater belongs when operating in a heating mode;

Whether the electric heater is dry-fired is determined according to the outlet air temperature, and if the electric heater is dry-fired, the inner fan that controls the air conditioner operates according to a predetermined state.
The method of claim 14 further comprising the steps of:

Detecting the temperature of the electric heater. If the detected electric heater temperature is greater than the electric heater temperature alarm threshold, the electric heater temperature alarm unit is used to report the fault;

Whether the electric heater is dry or not is determined according to whether the outlet air temperature and the electric heater temperature alarm unit report a fault.
The method of claim 14 or 15, further comprising the steps of:

Connecting the first contactor switch to the first end of the electric heater;

A second contactor switch is coupled to the second end of the electric heater.
The method according to claim 16, wherein the determining whether the electric heater is dry burned is specifically:

Disconnecting the first contactor switch;

Turn off the electric heater;

Determining whether the electric heater temperature alarm unit reports a fault when the first interval time elapsed since the electric heater is turned off is greater than a set first time threshold, and if so, determining that the electric heater is dry, and determining the number A contactor switch has failed.
The method of claim 17, wherein determining whether the electric heater has a dry burn further comprises the steps of:

Determining whether the electric heater temperature alarm unit reports a fault when the first interval time is greater than the first time threshold, and if the result is no, determining whether the electric heater temperature alarm unit is determined when the first interval time is greater than the first time threshold If the second interval time after the start of the fault is greater than a set second time threshold, whether the outlet air temperature is greater than a set first temperature threshold, and if so, determining that the electric heater is dry and the first contact occurs The switch is faulty.
The method of claim 18, wherein determining whether the electric heater has a dry burn further comprises the steps of:

The determining whether the air outlet temperature is greater than a first temperature threshold when the second interval time is greater than the second time threshold, and if the result is no, performing the following operations:

Close the inner fan;

Determining whether the exit air temperature is greater than a set second temperature threshold when the third interval time elapsed since the closing of the inner fan is greater than a set third time threshold;

If yes, it is judged that the electric heater is dry and the first contactor switch is faulty; if not, it is judged that the electric heater is normally turned off, and the first contactor switch is normal.
The method according to any one of claims 17 to 19, wherein the determining whether the electric heater has a dry burn further comprises the steps of:

If it is determined that the electric heater is dry and the first contactor switch is faulty, further perform the following operations:

Disconnecting the second contactor switch;

Determining whether the exit air temperature is greater than a set third temperature threshold when the fourth interval time elapsed since the second contactor switch is turned off is greater than a set fourth time threshold;

If yes, it is judged that the electric heater is dry and the first contactor switch and the second contactor switch are faulty; if not, it is judged that the electric heater is dry, the first contactor switch is faulty, and the second contactor switch is normal. .
The method of any one of claims 16 to 20, wherein the determining whether the electric heater is dry or not further comprises:

If the electric heater is dry, the first and second contactor switches are faulty, and the control inner fan is in the first state when in standby;

And/or, if the electric heater is dry, the first contactor switch is faulty, the second contactor switch is normal, and the control inner fan is in the second state during standby;

And/or, if the electric heater is normally turned off and the first contactor switch is normal, the control inner fan is in the third state during standby.
The method of claim 21, wherein

In the first state, the inner fan is opened according to the middle wind speed;

And/or, in the second state, the inner fan is turned off;

And/or, the fan is turned off in the third state.
The method of any of claims 15-22, wherein the electric heater temperature alarm threshold has a value in the range of 150-250 °C.
A method according to any one of claims 17 to 23, wherein

The first time threshold ranges from 1 to 10 minutes;

And/or, the second time threshold ranges from 1 to 10 minutes;

And/or, the third time threshold ranges from 1 to 10 minutes;

And/or, the fourth time threshold ranges from 5 to 10 minutes;

And/or, the first temperature threshold ranges from 50 to 70 ° C;

And/or, the second time threshold ranges from 50 to 70 ° C;

And/or, the third time threshold ranges from 50 to 70 °C.
The method according to any one of claims 14 to 24, wherein when the electric heater is dry-fired, a prompt is issued by the fault prompting unit.
The method according to claim 25, wherein the fault prompting unit is selected from one or more of a display unit, a speaker, and an indicator light, and prompts in the form of text, image, voice, buzzer, and/or flashing light. .
An air conditioner comprising:

Electric heaters;

Inner fan

An electric heater protection device, the electric heater protection device according to any one of claims 1 to 13.
A computer readable storage medium having stored thereon a computer program, the program being executed by a processor to perform the steps of the method of any of claims 14-26.
An air conditioner, comprising: a processor, a memory, and a computer program stored on the memory and operable on the processor, the processor executing the program to implement the steps of the method of any one of claims 14-26 .