CN110346405B - A gas stove anti-dry detection method, detection device and gas stove - Google Patents

Abstract

The invention discloses a dry burning prevention detection method and device for a gas stove, and the gas stove, wherein the emissivity alpha of a pan bottom and the infrared radiation energy E1 emitted by the pan bottom are obtained, and then the formula E1=alpha delta T is adopted ⁴ Calculating the bottom temperature T, judging whether the gas stove is in a dry burning state according to the bottom temperature T, and closing a gas valve or giving an alarm if the gas stove is in a plurality of burning states; therefore, according to the invention, the temperature of the pan bottom is calculated through the obtained emissivity of the pan bottom, and when different pans are used, the emissivity of the corresponding pan bottom is used for calculating the temperature of the pan bottom, so that a more accurate temperature value is obtained, the problem of inaccurate temperature measurement caused by large difference of the emissivity of the pan body in the prior art is solved, the accuracy of the detected temperature of the pan bottom is improved, and the accuracy of dry burning prevention control is improved.

Description

A gas stove anti-dry detection method, detection device and gas stove

technical field

The invention belongs to the technical field of gas stoves, and in particular relates to a gas stove anti-dry detection method, a detection device and a gas stove.

Background technique

The gas stove is a necessary daily necessities for the family and plays a very important role in daily life.

Gas stoves have a wide range of applications, and it is easy to forget to monitor the cooking, causing the pot to continue to dry, damaging the pot or causing a fire. The dry-boil prevention system can effectively detect the dry-boil state, alarm the user or close the gas valve in time.

The current anti-dry solution has the following disadvantages:

1. The temperature measuring device used in the anti-dry burning application in the existing gas stove uses a contact temperature sensor such as a thermocouple or a thermistor. The temperature measuring device directly contacts the bottom of the pot or contacts the bottom of the pot through a metal shell to measure the temperature. Must be in contact with the bottom of the pan. The heat is transferred from the bottom of the pot to the temperature measuring device through heat conduction, and poor contact will cause large errors. In order to avoid direct heating of the temperature measuring device by the high-temperature flame, causing large errors, the burner needs to be specially designed, and the design is limited. See CN101382303B, there are certain defects in this structure, and the flame is easy to directly heat the temperature measuring probe, causing interference; the poor contact between the temperature measuring probe and the bottom of the pot is also likely to cause measurement errors.

2. The existing scheme uses infrared temperature measurement technology to detect the temperature of the bottom of the pot and is applied to the gas stove. However, there is a flame in the gas stove, and the flame will cause certain interference. Although the flame density is very low, the infrared radiation emitted will still affect the temperature measurement results. In order to solve this problem, existing infrared temperature measurement schemes for gas stoves, such as CN 102374529A and CN102374530A, use a metal isolation ring to separate the flame, and the metal isolation ring is close to the bottom of the pot, and the temperature measurement device still needs to be in contact with the bottom of the pot. This design does not completely improve the disadvantages of the thermocouple-type traditional gas stove temperature measurement method. Poor contact is still easy to cause errors, and the flame directly heats the metal isolation ring. It is also easy to cause errors. In order to reduce the heat brought by the flame, the burner structure Special optimization is required.

3. In the existing infrared temperature measurement scheme for gas stoves, the accuracy of temperature measurement is greatly affected by the emissivity of the bottom of the pot. Existing infrared temperature measurement schemes for gas stoves use commonly used full-spectrum infrared detectors (commonly used are generally 5.5-14um). When the detection emissivity of the pot varies greatly, it will cause a large detection error. For example, a black iron pot and a stainless steel bright bottom pot at the same temperature have a large difference in infrared emissivity. If the same full-spectrum infrared detector is used to detect, the signal strength will be greatly different, and the resulting temperature value will be wrong. Up to tens of degrees. A few schemes, such as CN 102374530A, use a high-temperature-resistant metal sheet to contact the bottom of the pot. What the infrared temperature measurement actually detects is the infrared radiation intensity of the high-temperature-resistant metal sheet, which is not affected by the emissivity of the bottom of the pot. However, the temperature measuring device is a contact type, which does not give full play to the non-contact advantages of infrared temperature measurement, loses the meaning of infrared temperature measurement, and cannot avoid the influence of poor contact and flame heating metal isolation ring interference.

Contents of the invention

The invention provides a dry-burning prevention detection method of a gas stove, which improves the accuracy of detected pan bottom temperature and improves the accuracy of dry-burning prevention control.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions to achieve:

A gas stove anti-dry detection method, the method comprising:

Obtain the emissivity α of the bottom of the pot and the infrared radiation energy E1 emitted by the bottom of the pot itself;

Calculate the pot bottom temperature T according to the formula E1=αδT ⁴ ; where δ is the Stefan-Boltzmann constant;

Judging whether the gas stove is in a dry state according to the temperature T of the bottom of the pot;

If so, close the gas valve or alarm.

Further, the obtaining of the emissivity α of the bottom of the pot and the infrared radiation energy E1 emitted by the bottom of the pot itself; specifically includes:

Sending pulses of infrared radiation to the bottom of the pan through a calibrated light source;

The infrared radiation energy at the bottom of the pot is received by the temperature measuring infrared detector and converted into an electrical signal V; the electrical signal V is a superposition of a DC signal V1 and a pulse signal V2;

Obtain the infrared radiation energy E1 emitted by the bottom of the pot itself according to the DC signal V1;

Calculate the reflectivity β=V2*m of the bottom of the pan, where m is a constant;

Calculate the infrared emissivity of the pan bottom α=1-β.

Still further, an optical filter is installed on the temperature measuring infrared detector, the optical filter is a narrow bandpass optical filter, and the central wavelength of the optical filter is in the range of 3.4um to 4.4um; the correction light source The infrared radiation emitted has a wavelength corresponding to the filter.

Furthermore, the detection method also includes:

After obtaining the emissivity of the bottom of the pot, turn off the correction light source;

Judging whether to change the pot according to the electrical signal V output by the temperature measuring infrared detector;

If so, turn on the calibration light source again, and re-detect the infrared reflectivity of the bottom of the pan.

A gas stove anti-dry burning detection device, comprising:

The infrared detection module is used to obtain the emissivity α of the bottom of the pot and the infrared radiation energy E1 emitted by the bottom of the pot itself;

The judging module is used to calculate the pot bottom temperature T according to the formula E1=αδT ⁴ ; where δ is the Stefan-Boltzmann constant; judge whether the gas stove is in a dry state according to the pot bottom temperature T; if so, turn off the gas valve or alarm.

Further, the infrared detection module includes:

Calibrated light source for sending pulses of infrared radiation to the bottom of the pan;

A temperature-measuring infrared detector is used to receive the infrared radiation energy at the bottom of the pot and convert it into an electrical signal V; the electrical signal V is a superposition of a DC signal V1 and a pulse signal V2;

Inquiry calculation module, for obtaining the infrared radiation energy E1 that the bottom of the pot itself sends according to DC signal V1; Calculate the reflectivity β=V2*m at the bottom of the pot, wherein, m is a constant; Calculate the infrared emissivity α=1- at the bottom of the pot beta.

Still further, an optical filter is installed on the temperature measuring infrared detector, the optical filter is a narrow bandpass optical filter, and the central wavelength of the optical filter is in the range of 3.4um to 4.4um; the correction light source The infrared radiation emitted has a wavelength corresponding to the filter.

Furthermore, the query calculation module is also used to judge whether to change the pot according to the electrical signal V output by the temperature measuring infrared detector.

A gas stove includes a burner and the above-mentioned anti-dry burning detection device.

Further, the anti-dry detection device is arranged on one side of the burner, facing the center of the bottom of the pot; or, a light hole is opened at the center of the burner, and the detection device is arranged on the light hole. directly below the hole.

Compared with the prior art, the advantages and positive effects of the present invention are: the gas stove anti-dry detection method, detection device and gas stove of the present invention, by obtaining the emissivity α of the bottom of the pot and the infrared radiation energy emitted by the bottom of the pot itself E1, then calculate the temperature T of the bottom of the pot by the formula E1= ^αδT4 , judge whether the gas stove is in a dry burning state according to the temperature T of the bottom of the pot, if it is in a dry burning state, then close the gas valve or give an alarm; therefore, the present invention obtains The emissivity of the bottom of the pot is used to calculate the temperature of the bottom of the pot. When different pots are used, the emissivity of the corresponding pot bottom is used to calculate the temperature of the bottom of the pot, and a more accurate temperature value is obtained, which solves the problem of large differences in the emissivity of pots in the prior art. The problem of inaccurate temperature measurement has been solved, the accuracy of the detected bottom temperature of the pot has been improved, and the accuracy of anti-dry burning control has been improved.

Other features and advantages of the present invention will become more apparent after reading the detailed description of the embodiments of the present invention in conjunction with the accompanying drawings.

Description of drawings

Fig. 1 is a schematic structural view of an embodiment of the gas cooker proposed by the present invention;

Fig. 2 is a schematic structural view of another embodiment of the gas stove proposed by the present invention;

Fig. 3 is the front view of an embodiment of the gas stove anti-dry burning detection device proposed by the present invention;

Fig. 4 is the top view of Fig. 3;

Fig. 5 is a structural diagram of another embodiment of the gas stove anti-dry burning detection device proposed by the present invention;

Fig. 6 is the pulse signal sent by the correction light source;

Fig. 7 is the signal that temperature measuring infrared detector receives;

Fig. 8 is a flow chart of an embodiment of the detection method for preventing dry burning of the gas stove proposed by the present invention.

Reference signs:

P, anti-dry detection device; 1, pot bottom; 2, burner; 2-1, light hole; 3, glass baffle;

4. Bottom plate; 5. Bracket; 6. Calibration light source; 7. Temperature measuring infrared detector; 7-1. Condenser; 8. Optical filter; 9. Circuit board; 10. Half-transparent mirror.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

The material of the pot is different, and its reflectivity is different. The emissivity of the black bottom pot can generally reach 0.9, and the stainless steel bright bottom pot is around 0.4. If the same emissivity calculation is used when using different pots, temperature measurement errors will inevitably be introduced. To solve this technical problem, this embodiment proposes a gas stove anti-dry detection method, a detection device and a gas stove. By detecting the reflectivity of the bottom of the pot, the temperature of the bottom of the pot is calculated according to the reflectivity of the bottom of the pot, which improves the detected temperature of the bottom of the pot. The accuracy of temperature improves the accuracy of anti-dry burning control.

Next, the gas stove, the anti-dry detection device and the anti-dry detection method will be described in detail.

The gas stove of this embodiment mainly includes a burner 2 and a detection device P for preventing dry burning. A light hole 2-1 is provided at the center of the burner 2, and the anti-dry burning detection device P is arranged directly below the light hole 2-1, and is fixed with the bottom plate 4 of the gas stove, as shown in FIG. 1 .

The anti-dry burning detection device P is located directly below the light hole of the burner, and is far away from the burner 2, so it will not be disturbed by the high temperature of the burner 2. The light hole 2-1 is a circular or other shaped hole. The infrared radiation from the bottom of the pot 1 reaches the anti-dry detection device P through the light hole 2-1. The size of the light hole 2-1 ensures that it does not block the anti-drying The field of view S of the burning detection device P. A glass baffle 3 is installed on the upper surface of the light hole 2-1 to prevent dust from falling through the light hole 2-1 to the anti-dry detection device P below. Material, and can withstand a certain high temperature, such as sapphire.

As another preferred design solution of this embodiment, the anti-dry burning detection device P is arranged on the support 5 on one side of the burner 2, and faces the central position of the bottom of the pot 1, and the support 5 is fixed on the bottom plate 4 of the gas stove; The stove of the gas stove is provided with a light hole, and a glass baffle 3 is fixed on the light hole. The surface of the glass baffle 3 is flush with the surface of the stove, and the glass baffle 3 is used to prevent dust from falling through the light hole. To the anti-dry detection device P, the infrared radiation at the bottom of the pot passes through the glass baffle 3 and the light hole and enters the anti-dry detection device P, as shown in Figure 2. The anti-dry detection device P is inclined to the vertical line of the bottom of the pot, and the temperature of the bottom of the pot is detected through the flame of the gas stove during detection. The advantage of this design is: the field of view S of the anti-dry burning detection device P is not blocked by the burner 2; it is beneficial to the combustion design of the gas stove, and there is no need to open a light hole in the center of the burner, which does not affect the central flame, and ordinary combustion can be used It is also especially suitable for medium-fire direct-injection gas stoves.

The anti-boil-dry detection device P is used to implement the following anti-boil-dry detection method, which mainly includes the following steps, as shown in FIG. 8 .

Step S1: Obtain the infrared emissivity α of the bottom of the pan.

When infrared rays irradiate an object, the energy is either absorbed by the object, reflected by the object, or penetrated by the object. According to the law of energy conservation, incident energy = absorbed energy + reflected energy + transmitted energy.

Therefore, absorptivity+reflectivity+transmittance=100%.

If the object is opaque, its transmittance is 0, then the above formula becomes:

Absorption + reflectance = 100%.

Any opaque object is absorbing, reflecting, and emitting infrared energy (heat energy) at the same time.

If an object absorbs infrared energy (thermal energy), its temperature rises. When an object is in an isothermal state, the energy it emits is the same as the energy it absorbs, therefore, absorption rate = emission rate, the above formula becomes:

Emissivity + reflectivity = 100%.

The state of the pot on the gas stove can be approximated as absorption rate=emissivity, therefore, the emissivity α+reflection rate β=100% of the bottom of the pot. Therefore, the emissivity α=1-β can be calculated by detecting the reflectivity β of the bottom of the pan.

After the gas stove is ignited, first check whether there is a pot on the gas stove. If there is a pot, then continue to perform the following step S2. If there is no pot, it can continuously detect whether there is a pot on the gas stove, or give an alarm.

Whether there is a pot on the gas stove can be judged by detecting the reflectance β (or emissivity α) of the bottom of the pot. If the reflectance β (or emissivity α) is within the set range, it is determined that there is a pot on the gas stove; if the reflectance β (or emissivity α) is not within the set range, it is determined that there is no pot on the gas stove.

Step S2: Obtain the infrared radiation energy E1 emitted by the bottom of the pot itself.

Step S3: Calculate the pot bottom temperature T according to the formula E1=αδT ⁴ .

计算T。其中，δ为斯特藩-玻尔兹曼常数，具体可参见斯特藩-玻尔兹曼定律，此处不再赘述。It can be deduced from E1=αδT ⁴

Calculate T. Wherein, δ is the Stefan-Boltzmann constant, for details, please refer to the Stefan-Boltzmann law, which will not be repeated here.

Step S4: According to the temperature T of the bottom of the pot, it is judged whether the gas stove is in a dry state.

If the pot bottom temperature T≥set temperature threshold (such as 298°C), it means that the pot bottom temperature is very high, and it is determined that the gas stove is in a dry state, and then execute step S5: close the gas valve or give an alarm.

The anti-dry burning detection method of the gas stove of the present embodiment, by obtaining the emissivity α of the bottom of the pot and the infrared radiation energy E1 emitted by the bottom of the pot itself, and then calculating the temperature T of the bottom of the pot by the formula E1= ^αδT4 , according to the temperature T of the bottom of the pot Judging whether the gas stove is in a dry burning state, if it is in a dry burning state, then close the gas valve or alarm; The temperature of the bottom of the pot is calculated corresponding to the emissivity of the bottom of the pot, and a more accurate temperature value is obtained, which solves the problem of inaccurate temperature measurement caused by the large difference in the emissivity of the pot body in the prior art, and improves the detected temperature of the bottom of the pot Accuracy, improve the accuracy of anti-dry control.

In this embodiment, the dry-boil prevention detection device P includes an infrared detection module and a judging module. The infrared detection module is used to execute steps S1-S2, and the judging module is used to execute steps S3-S5.

The infrared detection module includes a calibration light source 6, a temperature-measuring infrared detector 7, and a query calculation module, as shown in FIGS. 3 and 4. The query calculation module and the judgment module can be integrated into the same circuit board 9.

Calibration light source 6: used to emit infrared radiation to the bottom of the pot 1, the emitted light is reflected by the bottom of the pot 1 and then enters the temperature measuring infrared detector 7.

Temperature measurement infrared detector 7: used to receive the infrared radiation energy of the bottom of the pot and convert the received optical signal into an electrical signal, such as thermopile, pyroelectric, indium gallium arsenic photodiode, selenium sulfide detector, etc. detector.

The viewing angle of the temperature-measuring infrared detector 7 determines the area of its detection area, and the final temperature value is obtained according to the total amount of thermal infrared radiation in the entire detection area. The distance from the temperature-measuring infrared detector 7 to the bottom of the pot 1 is relatively far, and the field angle of the temperature-measuring infrared detector 7 is limited to less than 10 degrees, so that the infrared radiation reaching the temperature-measuring infrared detector 7 from the bottom of the pot can pass through the center of the burner The clear light hole 2-1 without being blocked or disturbed by the burner. There is a concentrator 7-1 at the front end of the temperature-measuring infrared detector 7, and a lens-type or reflective-type concentrator can be used to limit the field angle of the detector, as shown in FIG. 3 .

An infrared filter 8 is installed on the temperature measuring infrared detector 7, the filter is a narrow band-pass filter, the center wavelength of the filter is in the range of 3.4um to 4.4um, and the half-maximum width of the passband is less than 5% of the center Wavelengths, or wider ones, have high transmittance in the passband and very low transmittance in other bands, so that optical methods rather than metal sleeves can be used to exclude interference from the flame. Ordinary infrared detectors generally have a wide detection range, such as 8 ~ 14um, the detection range is wide, and the flame has multiple strong infrared emission bands, some of which will fall within the detection range, causing great damage to infrared temperature measurement. interference. Reduce the interference of flame infrared light on the measurement results by optical methods rather than mechanical methods, and use the band of the flame transparent spectral window (to exclude flame interference), so that the wavelength of the temperature measuring infrared detector 7 is located in the flame transparent window area, reducing the impact of flame infrared radiation on the measurement results. The interference of the temperature measurement results enables the non-contact measurement of the bottom temperature of the pot in the gas stove, thereby realizing the non-contact anti-dry function. The wavelength of the infrared radiation emitted by the correction light source corresponds to the filter, which is a narrow bandpass filter, and the center wavelength of the filter is in the range of 3.4um to 4.4um, so as to avoid the influence of the flame on the emissivity detection of the bottom of the pot. Influence.

In this embodiment, the calibration light source 6 and the temperature measuring infrared detector 7 can be arranged side by side, as shown in FIG. 3 and FIG. 4 , the structure is relatively compact and the occupied space is small.

As another preferred design of this embodiment, the infrared detection module also includes a half-mirror 10 (or a solid prism), and the correction light source 6 and the temperature-measuring infrared detector 7 can pass through the half-mirror 10 (or a solid prism). Prism) combined, see Figure 5. The light sent by the correction light source 6 passes through the half-mirror 10 to the bottom of the pot, and the infrared radiation emitted by the bottom of the pot is reflected by the half-mirror 10 to the temperature-measuring infrared detector 7 . This structure can make the light sent by the correction light source 6 coaxial with the infrared light received by the temperature measuring infrared detector 7 (that is, the beam axes of the two beams of light coincide), that is, the light sent by the correction light source 6 passes through the half-transparent mirror 10 The transmission path after the transmission path is basically the same as the transmission path that the infrared light emitted by the bottom of the pan is sent to the half-mirror 10, and the ability of anti-dust and other interferences is stronger.

Specifically, the infrared emissivity α of the bottom of the pot and the infrared radiation energy E1 emitted by the bottom of the pot itself are obtained through the infrared detection module; specifically, the following steps are included:

Step S21: Calibrate the light source to send infrared radiation pulses to the bottom of the pot, as shown in FIG. 6 .

The calibration light source can be a laser, or a calibration light source in the form of a tungsten lamp, LED, laser, etc. When using this type of light source, the divergence angle of the light source needs to be limited so that its irradiation range is close to the field of view of the temperature measuring infrared detector. The divergence angle of the light source can be limited by lenses, reflectors, apertures, etc. The calibration light source can also use light of other bands, such as visible light, ultraviolet light, etc., but the reflectance measured by the infrared light source is the most accurate.

Step S22: Receive the infrared radiant energy of the bottom of the pan through the temperature measuring infrared detector and convert it into an electrical signal V; the electrical signal V is the superposition of the DC signal V1 and the pulse signal V2.

The temperature measuring infrared detector receives the infrared radiation emitted by the bottom of the pot itself, and also receives the infrared radiation pulse emitted by the correction light source reflected by the bottom of the pot, and the finally received optical signal is the superposition of the above two signals, that is, a DC signal The form of the superimposed pulse signal is shown in Figure 7. The DC signal represents the infrared radiation intensity of the bottom of the pot itself, which is used for infrared temperature measurement; Infrared light signal, the intensity of this signal is related to the reflectivity of the bottom of the pot, the higher the reflectivity of the bottom of the pot, the stronger the signal.

The infrared radiation emitted by the corrected light source reflected by the bottom of the pot and the infrared radiation emitted by the bottom of the pot are both within the detection range of the infrared detector for temperature measurement. The detector detects a range of wavelengths, such as 4.8um～5.0um, 3um～ 5.5um, etc., the light within the detection band range will be received, and the infrared radiation reflected by the bottom of the pot must also be within the detection band range. The correction light source can be a laser light source with only one wavelength, or a wide-band LED, tungsten lamp and other types of light sources. All or part of the infrared rays emitted by the correction light source are within the detection range of the detector.

The query calculation module executes the following steps S23 to S25.

Step S23: Obtain the infrared radiation energy E1 emitted by the bottom of the pot itself according to the DC signal V1.

There is a corresponding relationship between the electrical signal output by the temperature-measuring infrared detector and the radiation energy. For different detectors such as thermopiles and photodetectors, the corresponding relationship is different. For most detectors, the output signal voltage V∝ the received radiation energy E.

By querying the preset detector model-output electrical signal-radiation energy correspondence table, the radiation energy corresponding to the electrical signal is obtained. The correspondence table can be obtained by measuring with a standard black body radiation source.

For example, the emissivity α0 of the standard black body radiation source is 1, the infrared detector receives the radiation energy of the standard black body radiation source, and outputs the electrical signal V0, calculates the temperature value T0, and calculates E0 according to the formula E0=α0*δ*T0 ⁴ , δ is the Stefan-Boltzmann constant. Different radiant energy corresponds to different output electrical signals and temperature values. Therefore, different types of infrared detectors are used, and the corresponding electrical signal, temperature value, and radiation energy are obtained by using the above method, and a detector model-output electrical signal-radiation energy correspondence table is generated.

Therefore, E1 corresponding to V1 is obtained by querying the corresponding table.

Step S24: Calculate the reflectivity β=V2*m of the bottom of the pan, where m is a constant.

The constant m is related to the temperature measuring infrared detector and the calibration light source, and can be measured through a standard reflector. For example, use the same infrared detector, the same calibration light source, and a standard reflector with a known reflectance of β0 for testing. The infrared radiation from the calibration light source is irradiated on the standard reflector, and is received by the infrared detector after being reflected by the standard reflector. , and output the electrical signal V0, and then calculate m=β0/V0.

Step S25: Calculate the infrared emissivity α=1-β of the pan bottom.

After obtaining the reflectance β, use the formula α=1-β to calculate α.

Finally, the judging module calculates the pot bottom temperature T according to the formula E1=αδT ⁴ ; and judges whether the gas stove is in a dry state.

In this embodiment, the reflectance value is measured, and then the emissivity value is calculated. When different pots are used, the temperature of the bottom of the pot is calculated using the corresponding emissivity, so as to obtain a more accurate temperature value.

After obtaining the infrared emissivity of the bottom of the pan, turn off the calibration light source; however, during the use of the gas stove, the pan may be changed midway, so the query calculation module also needs to convert the electrical signal V Determine whether to change the pot; if so, turn on the calibration light source again, and re-test the infrared reflectivity of the bottom of the pot to avoid temperature measurement errors caused by changing the pot. Because changing the pot midway will cause the output electrical signal of the temperature measuring infrared detector to be abnormal, so when the electrical signal is abnormal, it is necessary to re-detect the reflectivity of the bottom of the pot, and correct the light source to go out after obtaining the reflectivity of the bottom of the pot.

The anti-dry-burning detection method of the gas stove, the anti-dry-burning detection device and the gas stove of this embodiment realize the non-contact detection of the temperature of the bottom of the pot by using infrared temperature measurement technology, and realize the non-contact dry-burning state of the gas stove Detection, compared with the contact detection scheme in the prior art, eliminates the interference of poor contact on temperature measurement; by detecting the reflectivity of the bottom of the pot, the emissivity of the bottom of the pot is calculated, which reduces the impact caused by the different emissivity of the bottom of the pot. The resulting temperature measurement error makes the temperature measurement result more accurate, reduces the false alarm or less alarm phenomenon of anti-dry burning, and makes the gas stove applicable to a wider range of pot types; by arranging filters on the temperature measurement infrared detector , using an optical method to isolate the interference of flame infrared radiation. Compared with the method of using a metal sleeve to isolate in the prior art, the optical method realizes non-contact, more concise and beautiful, and the layout design of the gas stove is more flexible.

The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art can still understand the foregoing embodiments. Modifications are made to the technical solutions described, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions claimed in the present invention.

Claims (6)

1. A gas stove anti-dry detection method, characterized in that: the method comprises: Obtain the emissivity α of the bottom of the pot and the infrared radiation energy E1 emitted by the bottom of the pot itself; specifically include: Sending pulses of infrared radiation to the bottom of the pan through a calibrated light source; The infrared radiation energy at the bottom of the pot is received by the temperature measuring infrared detector and converted into an electrical signal V; the electrical signal V is a superposition of a DC signal V1 and a pulse signal V2; Obtain the infrared radiation energy E1 emitted by the bottom of the pot itself according to the DC signal V1; Calculate the reflectivity β=V2*m of the bottom of the pan, where m is a constant; Calculate the infrared emissivity of the bottom of the pot α=1-β; The light emitted by the correction light source passes through the half-mirror to the bottom of the pot, and the infrared radiation emitted by the bottom of the pot is reflected to the temperature-measuring infrared detector by the half-mirror, so that the light emitted by the correction light source coaxial with the infrared light received by the temperature measuring infrared detector; Calculate the pot bottom temperature T according to the formula E1=αδT ⁴ ; where δ is the Stefan-Boltzmann constant; Judging whether the gas stove is in a dry state according to the temperature T of the bottom of the pot; If so, close the gas valve or alarm; The field angle of the temperature measuring infrared detector is limited to less than 10 degrees; The detection method also includes: After obtaining the emissivity of the bottom of the pot, turn off the correction light source; Judging whether to change the pot according to the electrical signal V output by the temperature measuring infrared detector; If so, turn on the calibration light source again, and re-detect the infrared reflectivity of the bottom of the pan. 2. The method according to claim 1, characterized in that: an optical filter is installed on the temperature measuring infrared detector, the optical filter is a narrow bandpass optical filter, and the central wavelength of the optical filter is It is within the range of 3.4um to 4.4um; the wavelength of the infrared radiation emitted by the correction light source corresponds to the filter. 3. A gas stove anti-dry detection device, characterized in that: comprising: The infrared detection module is used to obtain the emissivity α of the bottom of the pot and the infrared radiation energy E1 emitted by the bottom of the pot itself; The judging module is used to calculate the pot bottom temperature T according to the formula E1=αδT ⁴ ; where δ is the Stefan-Boltzmann constant; judge whether the gas stove is in a dry state according to the pot bottom temperature T; if so, turn off the gas valve or alarm; The infrared detection module includes: Calibrated light source for sending pulses of infrared radiation to the bottom of the pan; The temperature-measuring infrared detector is used to receive the infrared radiation energy at the bottom of the pot and convert it into an electrical signal V; the electrical signal V is the superposition of the DC signal V1 and the pulse signal V2; the field angle of the temperature-measuring infrared detector is limited is less than 10 degrees; Inquiry calculation module, for obtaining the infrared radiation energy E1 that the bottom of the pot itself sends according to DC signal V1; Calculate the reflectivity β=V2*m at the bottom of the pot, wherein, m is a constant; Calculate the infrared emissivity α=1- at the bottom of the pot β; the query calculation module is also used to judge whether to change the pot according to the electrical signal V output by the temperature measuring infrared detector; half-mirror, the light emitted by the correction light source passes through the half-mirror to the bottom of the pot, and the infrared radiation emitted by the bottom of the pot is reflected to the temperature-measuring infrared detector by the half-mirror, so that the The light emitted by the correction light source is coaxial with the infrared light received by the temperature measuring infrared detector. 4. The device according to claim 3, characterized in that: an optical filter is installed on the temperature measuring infrared detector, the optical filter is a narrow bandpass optical filter, and the central wavelength of the optical filter is It is within the range of 3.4um to 4.4um; the wavelength of the infrared radiation emitted by the correction light source corresponds to the filter. 5. A gas stove, characterized by comprising a burner, and the anti-dry burning detection device according to any one of claims 3 to 4. 6. The gas stove according to claim 5, characterized in that: the anti-dry detection device is arranged on one side of the burner, facing the center of the pot bottom; Alternatively, a light hole is opened at the central position of the burner, and the detection device is arranged directly below the light hole.

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