Electric heating equipment and control method thereof

Abstract

The invention discloses electric heating equipment and a control method thereof. The control method comprises the steps that the medium state is evaluated according to the running state of the electric heating equipment so as to judge whether overheating protection needs to be conducted on the electric heating equipment or not, and the control method does not need to collect any running parameters of related media. Therefore, a new control strategy for overheating protection of the electric heating equipment is provided.

Description

Technical Field

[0001] The present application relates to the field of electric heating, and more specifically, to an electric heating device for heating a fluid and a control method of the heating device. Background Art

[0002] Electric heating equipment is an important equipment in the industrial field. For example, in electric vehicles (such as hybrid vehicles or pure electric vehicles), electric heating equipment is usually installed to achieve temperature control of the vehicle interior environment. When working, a relatively low-temperature medium flows into the electric heating equipment, absorbs the heat of the heating resistor in the electric heating equipment, and then becomes a relatively high-temperature medium and flows out of the electric heating equipment.

[0003] If the temperature is too high due to problems with the flow of the medium (such as whether there is medium flow, the flow rate of the medium, whether there are bubbles in the medium, the viscosity of the medium, etc.), the electric heating equipment will be protected from overheating (such as locking the electric heating equipment) for safety reasons. Usually, this overheating protection strategy is very harsh and will cause the heater to fail to start normally or perform heating work normally.

[0004] To address this problem, a traditional approach is to add sensors to the system that sense the flow state of the medium, such as a medium flow sensor or a medium pressure pump, to provide the medium flow information to the controller for overheat protection decisions. However, this traditional approach requires the deployment of related sensors, which makes the control strategy of the electric heating equipment more complex and increases the probability of control defects.

[0005] Therefore, how to provide a new control strategy for overheating protection of electric heating equipment has become a technical problem that needs to be solved in the field. Summary of the invention

[0006] In view of this, the present application proposes an electric heating device for heating a fluid and a control method of the heating device, so as to provide a new control strategy for overheating protection of the electric heating device.

[0007] In a first aspect, an embodiment of the present application provides a control method for an electric heating device, the control method comprising: evaluating a medium state according to an operating state of the electric heating device itself to determine whether overheating protection is required for the electric heating device, wherein the control method does not require the collection of any operating parameters of the medium.

[0008] Optionally, the control method includes a control method for the electric heating device during a startup phase.

[0009] Optionally, the control method includes: obtaining standard operating status information of the electric heating equipment when the medium is in a normal working state, and comparing the current operating status information of the electric heating equipment with the standard operating status information to determine whether the electric heating equipment needs to be protected from overheating.

[0010] Optionally, if the current operating status information of the electric heating equipment conforms to the standard operating status information, there is no need to perform overheating protection on the electric heating equipment, otherwise, the electric heating equipment needs to be protected from overheating; or, if the current operating status information of the electric heating equipment is within the allowable range of the standard operating status information, there is no need to perform overheating protection on the electric heating equipment, otherwise, the electric heating equipment needs to be protected from overheating.

[0011] Optionally, the control method includes: obtaining a standard temperature or temperature range of a heating element of the electric heating device when the medium is in a normal working state, and comparing the current temperature of the heating element of the electric heating device with the standard temperature or temperature range to determine whether the electric heating device needs to be protected from overheating.

[0012] Optionally, the control method includes: obtaining a standard temperature change interval or a standard temperature rise rate change interval corresponding to a first predetermined time of the heating element of the electric heating device when the medium is in a normal working state, comparing the current temperature change difference of the heating element of the electric heating device corresponding to the first predetermined time with the standard temperature change interval or comparing the current temperature rise rate change difference of the heating element of the electric heating device corresponding to the first predetermined time with the standard temperature rise rate change interval to determine whether the electric heating device needs to be protected from overheating.

[0013] Optionally, the control method includes: making the electric heating device operate continuously for a second predetermined time at a predetermined power when the medium is in a normal working state, so as to obtain a standard temperature change interval or a standard temperature rise rate change interval of the heating element of the electric heating device; and / or making the electric heating device operate continuously for a second predetermined time at a predetermined power to obtain a current temperature change difference or a current temperature rise rate change difference of the heating element of the electric heating device, wherein the ratio of the predetermined power to the maximum power of the electric heating device is 0.1 to 1, preferably 0.2 to 0.8, more preferably 0.3 to 0.6, and most preferably 0.3 to 0.5; wherein the second predetermined time is 1-120 seconds, preferably 1-60 seconds, more preferably 2-30 seconds, and more preferably 2-10 seconds.

[0014] Optionally, the starting point of the second predetermined continuous operation time is when the electric heating device is started.

[0015] Optionally, the standard operating status information of the electric heating device when the medium is in a normal working state is obtained by analyzing large-scale data on the operation of the electric heating device, preferably using machine learning to analyze large-scale data.

[0016] Optionally, the control method includes that overheat protection of the electric heating device does not result in locking the electric heating device.

[0017] Optionally, when the electric heating device is overheated, the current operating power is recorded and a low operating power that is less than the current operating power is set. The device is operated at the low operating power for a third predetermined time. If the electric heating device is overheated again during this period, the low operating power is reset until the device is operated at the low operating power for the third predetermined time without overheating.

[0018] Optionally, the low operating power is 50% to 90% of the current operating power, preferably 60% to 80%.

[0019] Optionally, the third predetermined time is 10-60 seconds, preferably 15 to 30 seconds, and more preferably 20 seconds.

[0020] Optionally, if the electric heating device operates at a low power for a third predetermined period of time without overheating protection, the operating power is gradually increased to a predetermined power threshold. If overheating protection of the electric heating device occurs during this period, the low power is reset until the predetermined power threshold is reached without overheating protection occurring.

[0021] Optionally, the stepwise increasing of the operating power to a predetermined power threshold is performed by stepwise increasing a predetermined power increase value.

[0022] Optionally, the predetermined power threshold is 50%-90% of the maximum power of the electric heating device, preferably 60%-80%.

[0023] Optionally, if the operating power of the electric heating device reaches the predetermined power threshold, the overheat protection fault state is cleared to allow the electric heating device to operate at maximum power.

[0024] In a second aspect, an embodiment of the present application further provides an electric heating device, which is provided with a control device for executing the above-mentioned control method.

[0025] According to the technical solution of the present application, the medium state is evaluated according to the operating state of the electric heating device itself to determine whether the electric heating device needs to be protected from overheating, and there is no need to collect any operating parameters of the medium. In this way, a new control strategy for overheating protection of the electric heating device is proposed. In addition, in the technical solution of the present application, the medium state is evaluated according to the operating state of the electric heating device itself, and there is no need to set up a sensor for sensing the flow information of the medium, which reduces the cost, simplifies the circuit, simplifies the control strategy of the electric heating device, and reduces the probability of control defects. At the same time, the medium state is evaluated according to the operating state of the electric heating device to determine whether the electric heating device needs to be protected from overheating, which can more directly determine whether overheating protection is needed, and can more effectively protect the electric heating device. In addition, there is no need to detect the working current of the driving device of the medium, there is no need to determine the flow information of the medium according to the power of the driving device, and there is no need to establish communication with the driving device, which simplifies the circuit, simplifies the control strategy of the electric heating device, and reduces the probability of control defects.

[0026] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings constituting a part of the present application are used to provide a further understanding of the present application, and the schematic implementation modes and descriptions of the present application are used to explain the present application. In the accompanying drawings:

[0028] Figure 1 The figure is a flow chart of a control method of an electric heating device according to a preferred embodiment of the present application. DETAILED DESCRIPTION

[0029] The technical solution of the present application will be described in detail below with reference to the accompanying drawings and in combination with the implementation modes.

[0030] In a first aspect, an embodiment of the present application provides a control method for an electric heating device. The control method includes the following contents: evaluating a medium state according to an operating state of the electric heating device itself to determine whether overheat protection is required for the electric heating device, wherein the control method does not need to collect any operating parameters of the medium.

[0031] Optionally, in an embodiment of the present application, the control method includes a control method for the electric heating device during a startup phase.

[0032] Optionally, in the embodiment of the present application, the operating status information of the electric heating device may be used to evaluate the medium status to determine whether the electric heating device needs to be protected from overheating.

[0033] Optionally, in the implementation manner of the present application, standard operating status information may be set to evaluate the medium status.

[0034] Specifically, the control method may include the following: obtaining standard operating state information of the electric heating device when the medium is in a normal working state, and comparing the current operating state information of the electric heating device with the standard operating state information to determine whether overheat protection of the electric heating device is required.

[0035] Optionally, in the implementation manner of the present application, the current operating status information may be directly compared with the standard operating status information, or the current operating status information may be compared with a range determined based on the standard operating status information.

[0036] Optionally, in an embodiment of the present application, if the current operating status information of the electric heating device meets the standard operating status information, the electric heating device does not need to be protected from overheating; otherwise, the electric heating device needs to be protected from overheating.

[0037] Alternatively, if the current operating state information of the electric heating device is within the allowable range of the standard operating state information, the electric heating device does not need to be overheated protected, otherwise, the electric heating device needs to be overheated protected. The allowable range of the standard operating state information is a range set based on the standard operating state information and with a preset error. The preset error can be determined according to specific circumstances.

[0038] Optionally, in the embodiment of the present application, the operating status information of the electric heating device may be temperature, power, etc.

[0039] Optionally, in the embodiment of the present application, the operating status information of the electric heating device may be the temperature of the heating element of the electric heating device; or, it may be the difference in temperature change of the heating element at a certain time interval; or, it may be the difference in the change of the temperature rise rate of the heating element at a certain time interval. In the embodiment of the present application, the temperature-related information of the heating element can more accurately reflect the operating status information of the electric heating device, and the method of detecting the temperature of the heating element is relatively simple. Using the temperature-related information of the heating element of the electric heating device to characterize the operating status information of the electric heating device can more easily and directly obtain the operating status information of the electric heating device.

[0040] Optionally, in the embodiment of the present application, the temperature of the heating element may be detected by providing a temperature sensor.

[0041] Optionally, in the embodiment of the present application, the control method may include the following: obtaining a standard temperature or temperature range of a heating element of the electric heating device when the medium is in a normal working state, and comparing the current temperature of the heating element of the electric heating device with the standard temperature or temperature range to determine whether the electric heating device needs to be overheated protected.

[0042] Optionally, whether the electric heating device needs to be protected from overheating is determined based on the standard temperature of the heating element. When the current temperature of the heating element reaches the standard temperature, the electric heating device does not need to be protected from overheating; when the current temperature of the heating element does not reach the standard temperature, the electric heating device needs to be protected from overheating.

[0043] Optionally, whether the electric heating device needs to be protected from overheating is determined based on the temperature range of the heating element. When the current temperature of the heating element is within the temperature range, the electric heating device does not need to be protected from overheating; when the current temperature of the heating element is not within the temperature range, the electric heating device needs to be protected from overheating.

[0044] Optionally, in the embodiment of the present application, the control method may include the following contents. Obtain the standard temperature change interval or the standard temperature rise rate change interval of the heating element of the electric heating device corresponding to the first predetermined time when the medium is in a normal working state, compare the current temperature change difference of the heating element of the electric heating device corresponding to the first predetermined time with the standard temperature change interval, or compare the current temperature rise rate change difference of the heating element of the electric heating device corresponding to the first predetermined time with the standard temperature rise rate change interval, so as to determine whether the electric heating device needs to be overheated protected. The temperature change or the temperature rise rate change is the change in temperature or the change in temperature rise rate within a period of time, and the first predetermined time is the time interval corresponding to the calculation of the temperature change or the temperature rise rate change.

[0045] Specifically, if the current temperature change difference is within the standard temperature change range, the electric heating device does not need to be protected from overheating; if the current temperature change difference is not within the standard temperature change range, the electric heating device needs to be protected from overheating.

[0046] Specifically, if the current temperature rise rate change difference is within the standard temperature rise rate change range, the electric heating equipment does not need to be protected from overheating; if the current temperature rise rate change difference is not within the standard temperature rise rate change range, the electric heating equipment needs to be protected from overheating.

[0047] Optionally, in an embodiment of the present application, regarding how to obtain a standard temperature change interval, a standard temperature rise rate change interval, a current temperature change difference, and a current temperature rise rate change difference, the control method may include the following contents.

[0048] The electric heating device is made to work continuously for a second predetermined time at a predetermined power when the medium is in a normal working state, so as to obtain a standard temperature change interval or a standard temperature rise rate change interval of a heating element of the electric heating device.

[0049] And / or, the electric heating device is operated continuously for a second predetermined time at a predetermined power to obtain a current temperature change difference or a current temperature rise rate change difference of a heating element of the electric heating device.

[0050] The ratio of the predetermined power to the maximum power of the electric heating device is 0.1 to 1, preferably 0.2 to 0.8, more preferably 0.3 to 0.6, and most preferably 0.3 to 0.5.

[0051] The second predetermined time is 1-120 seconds, preferably 1-60 seconds, more preferably 2-30 seconds, and more preferably 2-10 seconds.

[0052] Optionally, in an embodiment of the present application, the starting point of the second predetermined continuous operation time is when the electric heating device is started.

[0053] Specifically, in the embodiments of the present application, the temperature change may be observed according to the following contents.

[0054] When the electric heating device starts heating, the electric heating device is controlled to work continuously at a predetermined power for a second predetermined time, and then the electric heating device is turned off for 2S to observe the temperature change of the heating element. The ratio of the predetermined power to the maximum power is Y%, and Y can be 20-50; the predetermined time can be set between 2 and 10S.

[0055] When the power is stopped, the time and amplitude of the temperature rise rate change of the heating element are calculated, and the current temperature rise rate change difference corresponding to the first predetermined time is calculated. When the current temperature rise rate change difference corresponding to the first predetermined time is not in the temperature rise rate change standard interval corresponding to the first predetermined time, it is considered that there is a problem with the medium, and the electric heating equipment needs to be overheated and the heating can be stopped. The first predetermined time can be 0.5S. The temperature rise rate change standard interval can be less than a certain value, which can be set according to the experiment. In addition, the value may not be the same for different products.

[0056] Optionally, in the embodiment of the present application, the standard operating state information of the electric heating device when the medium is in a normal working state is obtained by analyzing large-scale data of the operation of the electric heating device. It is preferred to use machine learning to analyze large-scale data.

[0057] Optionally, in an embodiment of the present application, the control method includes performing overheat protection on the electric heating device without causing the electric heating device to be locked. Performing overheat protection on the electric heating device without causing the electric heating device to be locked can avoid non-compliance with requirements caused by locking the electric heating device, and can also avoid the medium not being able to flow normally due to low temperature.

[0058] Optionally, in the embodiment of the present application, when the electric heating device is overheated, the current operating power is recorded and a low row power that is less than the current operating power is set, and the electric heating device is operated for a third predetermined time at the low row power. If the electric heating device is overheated again during this period, the low row power is reset until the electric heating device is operated for the third predetermined time at the low row power without overheating. It should be noted that in the embodiment of the present application, after the low row power is reset, the time of operation at the low row power needs to be re-recorded, and the termination condition can only be met when the electric heating device is operated for a third predetermined time at a certain low row power without overheating in the meantime.

[0059] Optionally, in the embodiment of the present application, in the case of overheat protection, before controlling the electric heating device to run at low power for the third predetermined time, it can be determined whether the fault recovery condition is met. If the fault recovery condition is met, the electric heating device is controlled to run at low power for the third predetermined time; otherwise, the electric heating device is not controlled to run at low power for the third predetermined time. If the fault recovery condition is met, the subsequent steps are executed, and if the fault recovery condition is not met, the subsequent steps are not executed. In this way, there can be a buffer time before recovery to avoid continuous dry burning in a short period of time.

[0060] Optionally, in the embodiment of the present application, in the case of overheat protection, before controlling the electric heating device to operate at low power for a third predetermined time, a period of time is waited, and when the waiting time is reached, subsequent steps are performed. In this way, there can be a buffer time before recovery to avoid continuous dry burning in a short period of time.

[0061] Optionally, in an embodiment of the present application, the low operating power is 50% to 90% of the current operating power, preferably 60% to 80%.

[0062] Optionally, in the embodiment of the present application, the low row power can be set according to the temperature rise value of the heating element after the electric heating device is overheated protected. Specifically, the greater the rise value, the smaller the low row power. The specific value of the low row power can be calibrated according to experiments.

[0063] Optionally, in an embodiment of the present application, the third predetermined time for operation at low power is 10-60 seconds, preferably 15 to 30 seconds, and more preferably 20 seconds.

[0064] Optionally, in an embodiment of the present application, if the electric heating device operates at a low power for a third predetermined time without overheating protection, the operating power is gradually increased to a predetermined power threshold. If overheating protection of the electric heating device occurs during this period, the low power is reset until the predetermined power threshold is reached without overheating protection.

[0065] Optionally, in the implementation manner of the present application, the form of gradually increasing the operating power can be set according to the actual situation. For example, the operating power can be gradually increased by increasing the same value each time. Or, the operating power can be gradually increased by increasing power values ​​one by one.

[0066] Optionally, in an embodiment of the present application, the stepwise increase of the operating power to the predetermined power threshold is performed by gradually increasing the predetermined power increase value. Specifically, each time the operating power is increased, the operating power is increased by the predetermined power increase value. The specific value of the predetermined power increase value can be determined according to the specific situation.

[0067] In the implementation manner of the present application, the predetermined power threshold can be determined according to specific circumstances. Optionally, in the implementation manner of the present application, the predetermined power threshold is 50%-90% of the maximum power of the electric heating device, preferably 60%-80%.

[0068] Optionally, in the embodiment of the present application, if the operating power of the electric heating device reaches a predetermined power threshold, the overheat protection fault state is cleared and the electric heating device is allowed to operate at maximum power. Only after reaching the predetermined power threshold is the electric heating device allowed to operate at maximum power to avoid continued dry burning at high power after the overheat protection is restored.

[0069] Figure 1 Flow chart of the control method of the electric heating device according to the preferred embodiment of the present application. Figure 1 The control method provided in the implementation manner of the present application is exemplarily introduced.

[0070] In step S10, it is determined whether the electric heating device needs to be protected from overheating. If yes, step S11 is executed; if no, step S10 is executed.

[0071] Specifically, the current temperature rise rate change difference of the heating element of the electric heating device corresponding to the first predetermined time is compared with the temperature rise rate change standard interval to determine whether the electric heating device needs to be protected from overheating.

[0072] In addition, in the embodiment of the present application, when it is necessary to protect the electric heating device from overheating, a diagnostic trouble code (DTC) can be set to determine whether the electric heating device needs to be protected from overheating according to the status bit of the DTC. Specifically, bit0 and bit3 are used for judgment. Among them, bit0 indicates whether it is currently in a fault state, bit0=0 indicates that it is not currently in a fault state; bit0=1 indicates that it is currently in a fault state. Bit3 indicates whether aging is successful, bit3=0 indicates that aging is successful; bit3=1 indicates that aging is unsuccessful. In the case where aging is unsuccessful and it is currently in a fault state, overheating protection is required. Specifically, it can be determined whether the electric heating device needs to be protected from overheating by judging whether "confirmation bit bit3=1 and real-time bit bit0=1" are satisfied. In addition, when it is determined that the electric heating device needs to be protected from overheating, the temperature rise value of the heating element is counted.

[0073] In step S11, it is determined whether the fault recovery condition is met. If the fault recovery condition is met, step S12 is executed; otherwise, step S11 is executed.

[0074] Optionally, in an embodiment of the present application, when the fault recovery condition is met, the confirmation bit bit3=1 and the real-time bit bit0=0 can be set, and whether the fault recovery condition is met is determined by judging whether "confirmation bit bit3=1 and real-time bit bit0=0".

[0075] Optionally, in an embodiment of the present application, the fault recovery condition may be that at least one of the inlet temperature of the medium inlet of the electric heating device, the outlet temperature of the medium outlet, and the temperature of the heating element is less than the preset temperature and lasts for a fourth predetermined time. In an embodiment of the present application, the preset temperature and the fourth predetermined time may be determined according to specific circumstances. For example, the value range of the preset temperature may be greater than or equal to 30 degrees Celsius and less than or equal to 50 degrees Celsius. Preferably, the pre-trial temperature is 40 degrees Celsius. The value range of the fourth predetermined time may be greater than or equal to 50s and less than or equal to 70s. Preferably, the fourth predetermined time is 60s.

[0076] Optionally, in the embodiment of the present application, when the fault recovery condition involves at least two of the inlet temperature, the outlet temperature and the temperature of the heating element, the fault recovery condition may also include that the difference between the maximum temperature value and the minimum temperature value is less than a preset temperature difference value. For example, the range of the preset temperature difference value may be greater than or equal to 3 degrees Celsius and less than or equal to 6 degrees Celsius. Preferably, the preset temperature difference value is 5 degrees Celsius.

[0077] In step S12, it is determined whether the pre-aging waiting is over. If so, step S13 is executed; if not, step S12 is executed.

[0078] In the implementation manner of the present application, the aging process refers to the process of clearing the overheat protection fault state when the electric heating device is overheated. Specifically, the aging process starts from controlling the electric heating device to operate at low power for a third predetermined time until the operating power of the electric heating device reaches a predetermined power threshold.

[0079] Before starting the aging process, you can set the pre-aging waiting time. After the fault recovery conditions are met, wait for a period of time. If the waiting time reaches the pre-aging waiting time, it is determined that the pre-aging waiting is over; if the waiting time does not reach the pre-aging waiting time, it is determined that the pre-aging waiting is not over.

[0080] Optionally, in the embodiment of the present application, the same pre-aging waiting time may be set for the number of aging processes, or different pre-aging waiting times may be set for the number of aging processes. Preferably, in the embodiment of the present application, the pre-aging waiting time may increase as the number of aging processes increases. Figure 1 In the process shown, the pre-aging waiting time can increase with the increase of the number of aging processes, and the corresponding relationship between the aging number and the pre-aging waiting time is preset. Specifically, the pre-aging waiting times corresponding to the aging numbers 1, 2, 3, 4, and 5 are 0, 1, 2, 5, and 30, respectively.

[0081] Specifically, in the implementation manner of the present application, it can be determined whether the pre-aging wait is ended by determining whether bit3=1 is satisfied and whether the waiting time reaches the pre-aging wait time corresponding to the current aging number.

[0082] In step S13, the electric heating device is controlled to operate at low power.

[0083] In step S14, it is determined whether the electric heating device needs to be protected from overheating. If so, step S15 is executed, the aging process ends, the aging times are increased by 1, and the pre-aging waiting time is adjusted according to the preset corresponding relationship. If not, step S16 is executed. Specifically, how to determine whether the electric heating device needs to be protected from overheating can refer to the contents described in the above embodiment.

[0084] In step S15, the low power is adjusted down, and the time during which the electric heating device is operated at the low power is reset to zero. In other words, after the low power is adjusted down, the time is reset when the device is operated at the low power again. After executing step S15, the process returns to executing step S11.

[0085] In step S16, it is determined whether the time of running at low power reaches a third predetermined time. If yes, step S17 is executed; if no, step S13 is executed.

[0086] In step S17, the operating power is increased, and the electric heating device is controlled to operate according to the adjusted operating power. Specifically, each time the operating power is increased, the operating power is increased by a predetermined power increase value. After executing step S17, step S18 is executed.

[0087] In step S18, it is determined whether the electric heating device needs to be protected from overheating. If so, step S11 is executed. The aging process ends, the aging times are increased by 1, and the pre-aging waiting time is adjusted according to the preset corresponding relationship. If not, step S19 is executed. Specifically, how to determine whether the electric heating device needs to be protected from overheating can refer to the contents described in the above embodiment.

[0088] In step S19, it is determined whether the operating power reaches a predetermined power threshold. If so, step S20 is executed; if not, step S17 is executed.

[0089] In step S20, the overheat protection fault state is cleared, allowing the electric heating device to operate at maximum power. Specifically, bit3 is set to 0, and the aging process ends.

[0090] Through the technical solution provided in the implementation mode of the present application, 1) after overheating protection occurs, in order to protect the electric heating equipment, power is restored only when specific conditions are met, so that the electric heating equipment can safely restore power without losing the protection function; 2) during the life cycle of the electric heating equipment, the lock caused by abnormal overheating of the electric heating equipment is released without losing the protection function and will not frequently cause overheating.

[0091] In a second aspect, an embodiment of the present application further provides an electric heating device, which is provided with a control device for executing the control method described in the above embodiment.

[0092] The preferred embodiments of the present application are described in detail above; however, the present application is not limited to the specific details in the above embodiments. Within the technical concept of the present application, a variety of simple modifications can be made to the technical solution of the present application, and these simple modifications all fall within the protection scope of the present application.

[0093] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this application will not further describe various possible combinations.

[0094] In addition, the various implementation modes of the present application may be arbitrarily combined, and as long as they do not violate the concept of the present application, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A control method for an electric heating device, the control method comprising: The medium state is evaluated according to the operating state of the electric heating device itself to determine whether the electric heating device needs to be protected from overheating, wherein the control method does not need to collect any operating parameters of the medium.

2. The control method of the electric heating device according to claim 1, wherein: The control method includes a control method for an electric heating device in a startup phase.

3. The control method of the electric heating device according to claim 1, wherein: The control method includes: obtaining standard operating status information of the electric heating device when the medium is in a normal working state, and comparing the current operating status information of the electric heating device with the standard operating status information to determine whether the electric heating device needs to be overheated protected.

4. The control method of the electric heating device according to claim 3, wherein: If the current operation status information of the electric heating device meets the standard operation status information, the electric heating device does not need to be protected from overheating; otherwise, the electric heating device needs to be protected from overheating; or If the current operation status information of the electric heating device is within the allowable range of the standard operation status information, the electric heating device does not need to be protected from overheating; otherwise, the electric heating device needs to be protected from overheating.

5. The control method of the electric heating device according to claim 3, wherein: The control method includes: obtaining a standard temperature or temperature range of a heating element of the electric heating device when the medium is in a normal working state, and comparing the current temperature of the heating element of the electric heating device with the standard temperature or temperature range to determine whether the electric heating device needs to be protected from overheating.

6. The control method of the electric heating device according to claim 3, wherein: The control method includes: obtaining a standard temperature change interval or a standard temperature rise rate change interval corresponding to a first predetermined time of a heating element of the electric heating device when a medium is in a normal working state, comparing a current temperature change difference of the heating element of the electric heating device corresponding to the first predetermined time with the standard temperature change interval or comparing a current temperature rise rate change difference of the heating element of the electric heating device corresponding to the first predetermined time with the standard temperature rise rate change interval to determine whether overheating protection is required for the electric heating device.

7. The control method of the electric heating device according to claim 3, 4, 5 or 6, wherein: The control method comprises: The electric heating device is operated continuously for a second predetermined time at a predetermined power when the medium is in a normal working state, so as to obtain a standard temperature change interval or a standard temperature rise rate change interval of a heating element of the electric heating device; and / or The electric heating device is operated continuously for a second predetermined time at a predetermined power to obtain a current temperature change difference or a current temperature rise rate change difference of a heating element of the electric heating device, Wherein, the ratio of the predetermined power to the maximum power of the electric heating device is 0.1 to 1, preferably 0.2 to 0.8, more preferably 0.3 to 0.6, and most preferably 0.3 to 0.5; The second predetermined time is 1-120 seconds, preferably 1-60 seconds, more preferably 2-30 seconds, and more preferably 2-10 seconds.

8. The control method of the electric heating device according to claim 7, wherein: The starting point of the second predetermined continuous operation time is when the electric heating device is started.

9. The control method of the electric heating device according to claim 3, wherein: The standard operating status information of the electric heating device when the medium is in a normal working state is obtained by analyzing large-scale data on the operation of the electric heating device, preferably using machine learning to analyze large-scale data.

10. The control method of the electric heating device according to claim 1, wherein: The control method includes overheat protection of the electric heating device, which does not result in locking the electric heating device.

11. The control method of the electric heating device according to claim 10, wherein: When the electric heating device is overheated, the current operating power is recorded and a low operating power that is less than the current operating power is set. The device is operated at the low operating power for the third predetermined time. If the electric heating device is overheated again during this period, the low operating power is reset until the device is operated at the low operating power for the third predetermined time without overheating.

12. The control method of the electric heating device according to claim 11, wherein: The low operating power is 50% to 90% of the current operating power, preferably 60% to 80%.

13. The control method of the electric heating device according to claim 11, wherein: The third predetermined time is 10-60 seconds, preferably 15 to 30 seconds, and more preferably 20 seconds.

14. The control method of the electric heating device according to claim 11, wherein: If the electric heating equipment operates at low power for the third predetermined time without overheating protection, the operating power is gradually increased to the predetermined power threshold. If overheating protection of the electric heating equipment occurs during this period, the low power is reset until the predetermined power threshold is reached without overheating protection.

15. The control method of the electric heating device according to claim 14, wherein: The stepwise increasing of the operating power to the predetermined power threshold is performed by stepwise increasing the predetermined power increase value.

16. The control method of the electric heating device according to claim 14, wherein: The predetermined power threshold is 50%-90% of the maximum power of the electric heating device, preferably 60%-80%.

17. The control method of the electric heating device according to claim 14, wherein: If the operating power of the electric heating device reaches the predetermined power threshold, the overheat protection fault state is cleared, allowing the electric heating device to operate at maximum power.

18. An electric heating device provided with a control device for executing the control method according to any one of claims 1 to 17.

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