1. The fire prevention control method of the electric water heater is characterized in that a temperature detection unit is arranged in an electric appliance chamber of the electric water heater and used for detecting the temperature in the electric appliance chamber, and the fire prevention control method of the electric water heater comprises the following steps:

in the heating process of the electric water heater, the heating rate in the electric appliance room is calculated according to the detection temperature of the temperature detection unit, the heating rate is compared with a preset heating rate, if the heating rate is greater than or equal to the preset heating rate, the fire risk is judged to exist, and the electric water heater stops heating; and/or

Comparing the current detection temperature with a preset threshold, if the current detection temperature is greater than or equal to the preset threshold, judging that the fire risk exists, and stopping heating the electric water heater; the preset threshold value is calculated according to influence factors, wherein the influence factors comprise temperature rise of an electric appliance chamber caused by water temperature in the liner, temperature rise caused by heating of a circuit system in the electric appliance chamber and environment temperature.

2. The fire prevention control method of an electric water heater according to claim 1, further comprising the steps of:

comparing the current detection temperature with a preset temperature, if the current detection temperature is greater than or equal to the preset temperature, the fire risk exists, and the electric water heater stops heating;

synchronously detecting in a mode of comparing the heating rate with a preset heating rate and in a mode of comparing the current detection temperature with a preset temperature, and stopping heating of the electric water heater if the fire risk is detected in any mode; and/or

And synchronously detecting by comparing the current detection temperature with a preset threshold value and by comparing the current detection temperature with the preset temperature, and stopping heating of the electric water heater if the fire risk is detected in any one of the modes.

3. The fire protection control method of an electric water heater according to claim 1, further comprising the following steps before comparing the temperature rise rate with a preset temperature rise rate and/or before comparing the current detected temperature with a preset threshold value:

comparing the current detection temperature with a preset temperature, if the current detection temperature is greater than or equal to the preset temperature, the fire risk exists, and the electric water heater stops heating;

and if the current detection temperature is lower than the preset temperature, comparing the heating rate with the preset heating rate and/or comparing the current detection temperature with a preset threshold value.

4. The fire prevention control method of an electric water heater according to claim 1, wherein the preset threshold value is (temperature in the inner container-ambient temperature) × proportionality constant + maximum ambient temperature + temperature rise due to heating of the circuit system in the electric appliance chamber, wherein the temperature in the inner container is the temperature in the inner container of the electric water heater.

5. The fire prevention control method of an electric water heater according to claim 1, wherein when the electric water heater is powered on, the current detected temperature is compared with a comparison value, and if the current detected temperature is less than the comparison value, the electric water heater starts to heat;

wherein the comparison value is the higher of the preset threshold and a detection preset value, and the detection preset value is the current detection temperature plus a preset value.

6. The fire prevention control method of an electric water heater according to claim 1, wherein the current preset threshold is compared with the preset threshold calculated last time, and if the current preset threshold is greater than or equal to the preset threshold calculated last time, the preset threshold is updated to the current preset threshold.

7. The fire prevention control method of an electric water heater according to claim 1, wherein the current preset threshold is compared with the preset threshold obtained by the previous calculation, and if the current preset threshold is smaller than the preset threshold obtained by the previous calculation, the decreasing amount of the preset threshold is calculated according to a calculation formula: and (3) the descending amount of the preset threshold value is (the current preset threshold value-the preset threshold value obtained by last calculation) proportional coefficient, so as to obtain the descending preset threshold value, and the preset threshold value is updated to the descending preset threshold value.

8. The fire prevention control method of an electric water heater according to any one of claims 1-7, further comprising, before comparing the current detected temperature with a preset threshold value:

and judging whether the current detection temperature is greater than or equal to a preset temperature value or not, if so, comparing the current detection temperature with a preset threshold value.

9. The fire prevention control method of an electric water heater according to any one of claims 1-7, wherein the number of times of stopping heating of the electric water heater is accumulated when the fire risk is detected, and whether the accumulated number of times is greater than or equal to a preset number of times is judged, and if so, the electric water heater gives an alarm.

10. The fire prevention control method of an electric water heater according to any one of claims 1-7, wherein before comparing the temperature increase rate with a preset temperature increase rate, it is determined whether the temperature increase degree within a preset time is greater than or equal to the preset temperature increase degree, and if so, the temperature increase rate is compared with the preset temperature increase rate.

11. The fire protection control method of an electric water heater according to any one of claims 1-7, wherein the preset temperature rise rate is heating power of the electric water heater/(specific heat capacity of water) volume of the inner container: density of water).

12. An electric water heater characterized by being controlled by the fire prevention control method of the electric water heater according to any one of claims 1 to 11.

Background

With the rapid development of modern science and technology, the continuous enhancement of safety consciousness of people puts forward higher requirements on the use safety of the water heater. For the parts of the electric chamber of the water heater, in which the electric devices of the electric water heater (such as a heating pipe and a temperature controller) are concentrated, because the closed space is narrow and the heat dissipation is limited, the heat can not be dissipated in time under the condition of long-term electrification, and the fire hazard of the electric chamber exists.

In the prior art, a temperature sensor is usually arranged in an electric appliance room, the temperature in the electric appliance room detected by the temperature sensor is compared with a preset temperature, and when the detected temperature in the electric appliance room is higher than the preset temperature, the existence of a fire risk is judged.

Disclosure of Invention

The invention aims to provide an anti-fire control method of an electric water heater and the electric water heater, which can detect whether the electric water heater has the risk of fire or not in a more sensitive mode, so that the electric water heater is stopped from heating, and the occurrence of danger is prevented.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a fire prevention control method of an electric water heater, wherein a temperature detection unit is arranged in an electric appliance chamber of the electric water heater and used for detecting the temperature in the electric appliance chamber, and the fire prevention control method of the electric water heater comprises the following steps:

in the heating process of the electric water heater: calculating the heating rate in the electric appliance room according to the detection temperature of the temperature detection unit, comparing the heating rate with a preset heating rate, and if the heating rate is greater than or equal to the preset heating rate, judging that the fire risk exists and stopping heating the electric water heater; and/or

Comparing the current detection temperature with a preset threshold, if the current detection temperature is greater than or equal to the preset threshold, judging that the fire risk exists, and stopping heating the electric water heater; the preset threshold value is calculated according to influence factors, wherein the influence factors comprise temperature rise of an electric appliance chamber caused by water temperature in the liner, temperature rise caused by heating of a circuit system in the electric appliance chamber and environment temperature.

The control method for preventing the electric water heater from firing comprises the steps that a temperature detection unit is arranged in an electric appliance room, in the heating process of the electric water heater, the temperature rising rate in the electric appliance room is calculated according to the detection temperature of the temperature detection unit, the temperature rising rate is compared with the preset temperature rising rate, if the temperature rising rate is larger than or equal to the preset temperature rising rate, the existence of the risk of firing is judged, and the electric water heater stops heating; and/or comparing the current detection temperature with a preset threshold, if the current detection temperature is greater than or equal to the preset threshold, judging that the fire risk exists, stopping heating the electric water heater, and detecting whether the fire risk exists in the electric water heater in a more sensitive mode, so that the electric water heater is stopped from heating, and the danger is prevented.

As a preferable aspect of the above fire prevention control method for an electric water heater, the fire prevention control method for an electric water heater further includes:

comparing the current detection temperature with a preset temperature, if the current detection temperature is greater than or equal to the preset temperature, judging that the fire risk exists, and stopping heating the electric water heater;

synchronously detecting in a mode of comparing the heating rate with a preset heating rate and in a mode of comparing the current detection temperature with a preset temperature, and stopping heating of the electric water heater if the fire risk is detected in any mode;

and synchronously detecting by comparing the current detection temperature with a preset threshold value and by comparing the current detection temperature with the preset temperature, and stopping heating of the electric water heater if the fire risk is detected in any one of the modes.

Through the synchronous detection of at least two kinds of modes, avoid the detection that certain detection mode error appears and lead to appear the problem, improve and detect the precision.

As a preferable scheme of the fire prevention control method of the electric water heater, before comparing the temperature rise rate with a preset temperature rise rate and/or before comparing the current detection temperature with a preset threshold, the method further comprises the following steps:

comparing the current detection temperature with a preset temperature, if the current detection temperature is greater than or equal to the preset temperature, judging that the fire risk exists, and stopping heating the electric water heater;

and if the current detection temperature is lower than the preset temperature, comparing the heating rate with the preset heating rate and/or comparing the current detection temperature with a preset threshold value.

Comparing the current detection temperature with a preset temperature, if the current detection temperature is greater than or equal to the preset temperature, judging that the fire risk exists, and avoiding the step of comparing the heating rate with the preset heating rate or comparing the current detection temperature with a preset threshold;

if the current detection temperature is less than the preset temperature, comparing the heating rate with the preset heating rate or comparing the current detection temperature with a preset threshold value so as to enable the fire of the electric water heater to be judged more accurately.

As a preferable embodiment of the fire prevention control method for the electric water heater, the preset threshold value is (temperature in the liner-ambient temperature) × proportionality constant + maximum ambient temperature + temperature rise due to heat generation of the circuit system in the electric appliance room, where the temperature in the liner is the temperature in the liner of the electric water heater.

The preset threshold value is obtained through the calculation formula, and influences of temperature rise of the electric appliance chamber caused by the temperature of water in the liner, temperature rise caused by heating of a circuit system in the electric appliance chamber and environment temperature are covered.

As a preferred scheme of the fire prevention control method of the electric water heater, when the electric water heater is powered on, the current detection temperature is compared with a comparison value, and if the current detection temperature is smaller than the comparison value, the electric water heater starts to heat;

wherein the comparison value is the higher of the preset threshold and a detection preset value, and the detection preset value is the current detection temperature plus a preset value.

The risk that the electric water heater stops heating due to high temperature of the electric appliance room when the electric water heater is powered on is avoided through the steps.

As a preferable scheme of the fire prevention control method for the electric water heater, a current preset threshold is compared with a preset threshold obtained by last calculation, and if the current preset threshold is greater than or equal to the preset threshold obtained by last calculation, the preset threshold is updated to the current preset threshold.

Whether the electric water heater has the risk of fire or not can be judged in time through the steps.

As a preferred scheme of the fire prevention control method for the electric water heater, a current preset threshold is compared with a preset threshold obtained by previous calculation, and if the current preset threshold is smaller than the preset threshold obtained by previous calculation, a decrease amount of the preset threshold is calculated according to a calculation formula: and (3) the descending amount of the preset threshold value is (the current preset threshold value-the preset threshold value obtained by last calculation) proportional coefficient, so as to obtain the descending preset threshold value, and the preset threshold value is updated to the descending preset threshold value.

The time delay descending condition of the electric water heater can be considered through the steps, and the detection is more accurate.

As a preferable scheme of the fire prevention control method of the electric water heater, before comparing the current detection temperature with the preset threshold, the method further includes:

and judging whether the current detection temperature is greater than or equal to a preset temperature value or not, if so, comparing the current detection temperature with a preset threshold value.

Through the judgment, the risk of fire is possible to exist only when the current detection temperature is greater than or equal to the preset temperature value, and if the current detection temperature is less than the preset temperature value, the risk of fire does not exist, and the current detection temperature does not need to be compared with the preset threshold value.

The method for controlling the fire prevention of the electric water heater preferably includes the steps of accumulating the times of stopping heating of the electric water heater when the fire risk is detected, judging whether the accumulated times are larger than or equal to the preset times, and giving an alarm to the electric water heater if the accumulated times are larger than or equal to the preset times.

The risk of fire is prevented by stopping attempts to heat the electric water heater; however, when the accumulated times is greater than or equal to the preset times, the risk cannot be eliminated by stopping heating, and the electric water heater gives an alarm to remind a user of checking.

As a preferable scheme of the fire prevention control method for the electric water heater, before the temperature rise rate is compared with the preset temperature rise rate, whether the temperature rise degree in the preset time is greater than or equal to the preset temperature rise degree is judged, and if so, the temperature rise rate is compared with the preset temperature rise rate.

Through the steps, the electric water heater is prevented from stopping heating due to short-term fluctuation of the heating rate of the electric water heater, and the detection is more accurate.

As a preferable mode of the fire prevention control method for the electric water heater, the preset temperature rise rate is heating power of the electric water heater/(specific heat capacity of water · volume of the inner container · density of water).

The preset heating rate is calculated according to the formula, and the calculation is convenient.

The invention also provides an electric water heater, which is controlled by adopting the fire prevention control method of the electric water heater.

The electric water heater is controlled by adopting the fire prevention control method of the electric water heater, so that the risk of fire can be avoided, the detection is more sensitive, and the service life of the electric water heater is prolonged.

The invention has the beneficial effects that:

the invention provides a fire prevention control method of an electric water heater, which comprises the steps of arranging a temperature detection unit in an electric appliance room, calculating the heating rate in the electric appliance room according to the detection temperature of the temperature detection unit in the heating process of the electric water heater, comparing the heating rate with a preset heating rate, judging that the fire risk exists if the heating rate is greater than or equal to the preset heating rate, and stopping heating the electric water heater; and/or comparing the current detection temperature with a preset threshold, if the current detection temperature is greater than or equal to the preset threshold, judging that the fire risk exists, stopping heating the electric water heater, and detecting whether the fire risk exists in the electric water heater in a more sensitive mode, so that the electric water heater is stopped from heating, and the danger is prevented.

The electric water heater provided by the invention is controlled by adopting the fire prevention control method of the electric water heater, so that the risk of fire can be avoided, the detection is more sensitive, and the service life of the electric water heater is prolonged.

Drawings

Fig. 1 is a flowchart of a fire prevention control method for an electric water heater according to an embodiment of the present invention;

fig. 2 is a flowchart of a fire prevention control method for an electric water heater according to a second embodiment of the present invention;

fig. 3 is a flowchart of how to obtain a preset threshold according to a second embodiment of the present invention;

fig. 4 is a flowchart of a fire prevention control method for an electric water heater according to a third embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", etc. are used in an orientation or positional relationship based on that shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

The first embodiment is as follows:

the embodiment provides a fire prevention control method of an electric water heater, a temperature detection unit is arranged in an electric appliance room of the electric water heater, and the temperature detection unit is used for detecting the temperature in the electric appliance room, as shown in fig. 1, the fire prevention control method of the electric water heater comprises the following steps:

in the heating process of the electric water heater, the temperature detection unit detects the temperature, the heating rate in the electric appliance room is calculated according to the detection temperature of the temperature detection unit, the heating rate is compared with the preset heating rate, if the heating rate is greater than or equal to the preset heating rate, the fire risk is judged to exist, and the electric water heater stops heating; and/or comparing the current detection temperature with a preset threshold, if the current detection temperature is greater than or equal to the preset threshold, judging that the fire risk exists, and stopping heating the electric water heater; the preset threshold is calculated according to influence factors, wherein the influence factors comprise temperature rise of an electric appliance chamber caused by water temperature in the liner, temperature rise caused by heating of a circuit system in the electric appliance chamber and environment temperature.

The control method for preventing the electric water heater from firing comprises the steps that a temperature detection unit is arranged in an electric appliance room, in the heating process of the electric water heater, the temperature rising rate in the electric appliance room is calculated according to the detection temperature of the temperature detection unit, the temperature rising rate is compared with the preset temperature rising rate, if the temperature rising rate is larger than or equal to the preset temperature rising rate, the existence of the risk of firing is judged, and the electric water heater stops heating; and/or comparing the current detection temperature with a preset threshold, if the current detection temperature is greater than or equal to the preset threshold, judging that the fire risk exists, stopping heating the electric water heater, and detecting whether the fire risk exists in the electric water heater in a more sensitive mode, so that the electric water heater is stopped from heating, and the danger is prevented.

Example two:

the embodiment provides an anti-fire control method of an electric water heater, which is a further improvement on the basis of the first embodiment, and comprises the following steps:

when the electric water heater is powered on, comparing the current detection temperature with the comparison value, and if the current detection temperature is less than the comparison value, starting heating the electric water heater; the comparison value is the higher of the preset threshold value and the detection preset value, and the detection preset value is the current detection temperature plus the preset value. The preset value is set according to requirements, and in the embodiment, the preset value is 5 ℃. The risk that the electric water heater stops heating due to high temperature of the electric appliance room when the electric water heater is powered on is avoided through the steps. It should be noted that: the current detection temperature does not have the condition of more than or equal to the comparison value, and when water is prevented from being used up, the indoor temperature of the electric appliance caused by electrification is high, so that the fire risk does not exist at the moment actually, and the condition that the fire risk exists is prevented from being obtained by misjudgment.

The fire prevention control method of the electric water heater further comprises the following steps: and comparing the current detection temperature with the preset temperature, and if the current detection temperature is greater than or equal to the preset temperature, judging that the fire risk exists, and stopping heating the electric water heater. The preset temperature is more than or equal to the highest temperature in the electric appliance room under the normal working condition of the electric water heater actually measured in the experiment. In this embodiment, the preset temperature is 80 ℃, and in other embodiments, the preset temperature is not limited to 80 ℃, and may be set to other temperatures.

Synchronously detecting in a mode of comparing the heating rate with a preset heating rate and in a mode of comparing the current detection temperature with a preset temperature, and stopping heating of the electric water heater if the fire risk is detected in any mode; and/or synchronously detecting by comparing the current detection temperature with a preset threshold value and comparing the current detection temperature with a preset temperature, and if the fire risk is detected in any one of the modes, stopping heating the electric water heater.

Through the synchronous detection of at least two kinds of modes, avoid the detection that certain detection mode error appears and lead to appear the problem, improve and detect the precision. If the judgment of any mode is 'yes', the fire risk is judged to exist, and the electric water heater stops heating.

Specifically, the preset threshold value is (temperature in the liner-ambient temperature) × proportionality constant + maximum ambient temperature + temperature rise caused by heating of a circuit system in the electric appliance room, wherein the temperature in the liner is the temperature in the liner of the electric water heater. The preset threshold value is obtained through the calculation formula, and influences of temperature rise of the electric appliance chamber caused by the temperature of water in the liner, temperature rise caused by heating of a circuit system in the electric appliance chamber and environment temperature are covered.

The temperature in the liner is obtained by a temperature sensor arranged in the liner of the electric water heater, and if a plurality of temperature sensors are arranged, the highest temperature in the liner is calculated. The ambient temperature may be measured by a temperature sensor or may be set to a constant value.

In this embodiment, the correlation formula of the temperature rise of the electric appliance chamber caused by the temperature of water in the liner is as follows: 50% (bladder temperature-ambient temperature) — appliance room temperature-ambient temperature. The ambient temperature for the fitting experiment was 20 ℃.

The temperature rise caused by the indoor heat generation of the electric appliance exceeds 15 ℃ and then the problem is considered to exist. (3kW of current flowing through a 0.1 Ω contact resistance causes a temperature rise of about 15 deg.C). The maximum ambient temperature is set to 30 ℃, so the offset is 30 ℃ +15 ℃ +45 ℃, thus yielding the preset threshold (temperature-20 in the bladder) × 0.5+ 45. When the temperature in the gallbladder is lower than 20 ℃, taking 20 ℃ and substituting the temperature into the formula.

As shown in fig. 3, it is shown how to obtain the preset threshold, specifically, the current preset threshold is compared with the preset threshold obtained by the last calculation, and if the current preset threshold is greater than or equal to the preset threshold obtained by the last calculation, the preset threshold is updated to the current preset threshold. Whether the electric water heater has the risk of fire or not can be judged in time through the steps.

Because the water temperature is reduced fast when the water heater uses hot water, the temperature in the electric appliance chamber can not be reduced immediately because of the reduction of the water temperature, and the preset threshold value obtained by calculation is smaller than the actual temperature in the electric appliance chamber, thereby easily judging that the risk of fire exists. Therefore, the calculated preset threshold value cannot be directly employed in this case. In the case of using hot water, the calculated preset threshold value is gradually decreased, and thus, whether the water heater is in a water use state is determined by comparing the difference between the calculated preset threshold values.

Specifically, the current preset threshold is compared with the preset threshold obtained by the previous calculation, and if the current preset threshold is smaller than the preset threshold obtained by the previous calculation, the decrease amount of the preset threshold is calculated according to a calculation formula: and (4) the descending amount of the preset threshold value is (the current preset threshold value-the preset threshold value obtained by the last calculation) proportional coefficient, so as to obtain the descending preset threshold value, and the preset threshold value is updated to the descending preset threshold value. Wherein, the proportionality coefficient is obtained according to time, and the proportionality coefficient is 0.03 in this embodiment. The temperature difference is 1 ℃ at the lowest. The time delay descending condition of the electric water heater can be considered through the steps, and the detection is more accurate.

It should be noted that: before comparing the current detection temperature with a preset threshold, the method further comprises the following steps after power-on detection:

and judging whether the current detection temperature is greater than or equal to a preset temperature value or not, if so, comparing the current detection temperature with a preset threshold value. Through the judgment, the risk of fire is possible to exist only when the current detection temperature is greater than or equal to the preset temperature value, and if the current detection temperature is less than the preset temperature value, the risk of fire does not exist, and the current detection temperature does not need to be compared with the preset threshold value.

Optionally, the preset temperature value is between 40 ℃ and 60 ℃, and in this embodiment, the preset temperature value is 50 ℃.

The temperature detection unit in the electric water heater detects the temperature in real time, the temperature sensor in the liner also detects the temperature in the liner in real time, the fire risk is detected, the times of stopping heating of the electric water heater are accumulated, whether the accumulated times is more than or equal to the preset times is judged, and if yes, the electric water heater gives an alarm; if not, the electric water heater is electrified again. The risk of fire is prevented by stopping attempts to heat the electric water heater; however, when the accumulated times is greater than or equal to the preset times, the risk cannot be eliminated by stopping heating, and the electric water heater gives an alarm to remind a user of checking. It should be noted that: the preset times can be set according to requirements and can be two times, three times, four times and the like.

Optionally, before comparing the temperature-increasing rate with the preset temperature-increasing rate, it is determined whether the temperature-increasing degree within the preset time is greater than or equal to the preset temperature-increasing degree, and if so, the temperature-increasing rate is compared with the preset temperature-increasing rate. Through the steps, the electric water heater is prevented from stopping heating due to short-term fluctuation of the heating rate of the electric water heater, and the detection is more accurate.

In this embodiment, the preset temperature increase rate is the heating power of the electric water heater/(the specific heat capacity of water · the volume of the inner container · the density of water). The preset heating rate is calculated according to the formula, and the calculation is convenient.

Example three:

as shown in fig. 4, the present embodiment provides a fire prevention control method for an electric water heater, which is slightly different from the second embodiment, and before comparing the temperature rising rate with the preset temperature rising rate and/or comparing the current detected temperature with the preset threshold, the method further includes the following steps:

comparing the current detection temperature with a preset temperature, if the current detection temperature is greater than or equal to the preset temperature, judging that the fire risk exists, and stopping heating the electric water heater;

and if the current detection temperature is less than the preset temperature, comparing the heating rate with the preset heating rate and/or comparing the current detection temperature with a preset threshold value.

Comparing the current detection temperature with a preset temperature, if the current detection temperature is greater than or equal to the preset temperature, judging that the fire risk exists, and performing the steps of comparing the heating rate with the preset heating rate and/or comparing the current detection temperature with a preset threshold value is not needed;

if the current detection temperature is less than the preset temperature, comparing the heating rate with the preset heating rate and/or comparing the current detection temperature with a preset threshold value so as to enable the fire of the electric water heater to be judged more accurately.

The subsequent detection steps are consistent with those in the second embodiment, and are not described herein again.

Example four:

the invention also provides an electric water heater, which is controlled by adopting the fire prevention control method of the electric water heater in any embodiment. The electric water heater is controlled by adopting the fire prevention control method of the electric water heater, so that the risk of fire can be avoided, the detection is more sensitive, and the service life of the electric water heater is prolonged.

The electric water heater is provided with a temperature detection unit in an electric appliance room, and the temperature detection unit detects the temperature in the electric appliance room.

In this embodiment, the temperature detection unit is temperature sensor, simple structure, and is with low costs, and the temperature measurement is comparatively convenient.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Numerous obvious variations, adaptations and substitutions will occur to those skilled in the art without departing from the scope of the invention. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.