Multi-parameter optical fiber sensing assembly and air purification device

Abstract

The invention relates to a multi-parameter optical fiber sensing assembly. The multi-parameter optical fiber sensing assembly specifically comprises an optical fiber, a plurality of detection FBGs and a signal receiving and processing unit. The detection FBGs are respectively inscribed on the optical fiber at intervals, and each detection FBG is coated with a single gas sensitive material; the signal receiving and processing unit receives reflected light signals of the detection FBGs scanned by an external light source respectively; calculating a reflection spectrum peak offset corresponding to the reflection light signal; and calculating concentration values of different gas pollutants according to the reflection spectrum peak offset. According to the whole assembly, a plurality of detection FBGs coated with single gas-sensitive materials are inscribed on the same optical fiber at intervals, concentration values of different gas pollutants are calculated by the signal receiving and processing unit according to reflection spectrum peak offset, the whole structure is simple, and high integration of multiple gas pollutant detection functions is realized. In addition, the invention further provides an air purification device comprising the multi-parameter optical fiber sensing assembly.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air purification, in particular to a multi-parameter optical fiber sensing assembly and an air purification device. BACKGROUND

[0002] In today's society, with the continuous improvement of people's quality of life and health consciousness, indoor air quality is increasingly concerned. As an important equipment for improving indoor air quality, the performance and reliability of the air purifier directly affect people's life experience and health status. However, the traditional air purifier has exposed many problems to be solved in practical application.

[0003] In order to realize the multi-parameter detection function, the traditional air purifier usually needs to be equipped with multiple independent sensors, each sensor is responsible for detecting different air parameters, such as particulate matter concentration, harmful gas content, etc. This configuration of multiple independent sensors leads to complex device structure and complex internal wiring. A large number of lines not only increase the difficulty of device assembly, but also are prone to line faults, affecting the stability and reliability of the device.

[0004] Therefore, there is an urgent need for an air purification device with high integration and simple structure. SUMMARY

[0005] Therefore, it is necessary to provide a multi-parameter optical fiber sensing assembly and an air purification device with high integration and simple structure in view of the above technical problems.

[0006] In a first aspect, the present application provides a multi-parameter optical fiber sensing assembly, comprising an optical fiber, a plurality of detection FBGs (Fiber Bragg Grating), and a signal receiving and processing unit;

[0007] Each of the detection FBGs is spaced and written on the optical fiber, and each of the detection FBGs is coated with a single gas sensitive material.

[0008] The signal receiving and processing unit receives the reflected light signal of each detection FBG scanned by an external light source; calculates the reflection spectrum peak shift value corresponding to the reflected light signal; and calculates the concentration value of different gas pollutants according to the reflection spectrum peak shift value.

[0009] In one embodiment, the multi-parameter optical fiber sensing assembly further comprises a light source, which is used to scan each detection FBG in a time division multiplexing manner.

[0010] In one embodiment, the light source is a single-wavelength light source, and the single wavelength is any value in the range of 400nm-10000nm.

[0011] In one of the embodiments, the multi-parameter optical fiber sensing assembly further comprises a circulator, and the light source directs the illumination to each of the detection FBGs through the circulator.

[0012] In one of the embodiments, the multi-parameter optical fiber sensing assembly further comprises a reference FBG inscribed on the optical fiber, and the reference FBG is not coated with the gas-sensitive material.

[0013] The signal receiving and processing unit is further configured to collect a reference reflected light signal of the reference FBG scanned by an external light source, and to denoise the reflected light signal of each of the detection FBGs scanned by the external light source according to the reference reflected light signal.

[0014] In one of the embodiments, the multi-parameter optical fiber sensing assembly further comprises an insulating sleeve, and the insulating sleeve is sleeved on the optical fiber.

[0015] In one of the embodiments, the signal receiving and processing unit is further configured to obtain an initial reflection peak wavelength of a current detection FBG in an environment with a known concentration of the gas pollutant, to calculate an actual reflection peak wavelength of the current detection FBG in a current environment to be measured according to the reflected light signal, to calculate a reflection spectrum peak shift according to the initial reflection peak wavelength and the actual reflection peak wavelength, to obtain a sensitivity corresponding to the gas-sensitive material coated on the current detection FBG, and to calculate a concentration of the gas pollutant detected by the current detection FBG according to the reflection spectrum peak shift and the sensitivity.

[0016] The multi-parameter optical fiber sensing assembly comprises an optical fiber, a plurality of detection FBGs, and a signal receiving and processing unit. Each of the detection FBGs is inscribed on the optical fiber at a certain interval, and each of the detection FBGs is coated with a single gas-sensitive material. The signal receiving and processing unit receives a reflected light signal of each of the detection FBGs scanned by an external light source. The signal receiving and processing unit calculates a reflection spectrum peak shift corresponding to the reflected light signal. The signal receiving and processing unit calculates a concentration value of a different gas pollutant according to the reflection spectrum peak shift. The entire assembly inscribes a plurality of detection FBGs coated with a single gas-sensitive material on the same optical fiber at intervals. The signal receiving and processing unit calculates a concentration value of a different gas pollutant according to the reflection spectrum peak shift. The entire assembly has a simple structure and realizes a high degree of integration of a plurality of gas pollutant detection functions.

[0017] In a second aspect, the application further provides an air purification device, comprising the multi-parameter optical fiber sensing assembly, an air purification assembly, and a controller.

[0018] The multi-parameter optical fiber sensing assembly and the air purification assembly are respectively connected to the controller.

[0019] In one of the embodiments, the air purification assembly comprises a plurality of purification units, each of the purification units is configured to perform purification operation on different types of gas pollutants;

[0020] The controller is further configured to receive different gas pollutant concentration values fed back by the multi-parameter optical fiber sensing assembly, compare the different gas pollutant concentration values with preset concentration threshold values of each gas pollutant, identify a target gas pollutant with concentration exceeding the threshold, and control a purification unit corresponding to the target gas pollutant in the air purification assembly to start.

[0021] In one of the embodiments, the air purification device further comprises a fan connected to the controller, and the controller is further configured to receive different gas pollutant concentration values fed back by the multi-parameter optical fiber sensing assembly, identify a pollution level according to the different gas pollutant concentration values, and adjust a rotating speed of the fan based on the pollution level.

[0022] The air purification device comprises the multi-parameter optical fiber sensing assembly, the air purification assembly, and the controller as described above, wherein the multi-parameter optical fiber sensing assembly writes a plurality of detection FBG intervals coated with a single gas sensitive material on the same optical fiber, and a signal receiving and processing unit is configured to calculate different gas pollutant concentration values according to a reflection spectrum peak shift amount, the overall structure is simple, and a high degree of integration of a plurality of gas pollutant detection functions is achieved, the controller controls the air purification assembly to perform purification operation based on different gas pollutant concentration values detected by the multi-parameter optical fiber sensing assembly, and the entire air purification device is highly integrated and simple in structure. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 FIG. 1 is a structural schematic diagram of the multi-parameter optical fiber sensing assembly in one of the embodiments;

[0024] Figure 2 FIG. 2 is a structural schematic diagram of the multi-parameter optical fiber sensing assembly in another of the embodiments;

[0025] Figure 3 FIG. 3 is a structural schematic diagram of the insulating sleeve and the optical fiber in one of the embodiments;

[0026] Figure 4 FIG. 4 is a structural schematic diagram of the air purification device in one of the embodiments. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0028] In one of the embodiments, as shown in FIG. 1, the multi-parameter optical fiber sensing assembly comprises an optical fiber 1, a plurality of FBG intervals 2 coated with a single gas sensitive material, and a signal receiving and processing unit 3. Figure 1As shown, a multi-parameter optical fiber sensing assembly is provided, which includes an optical fiber 110, a plurality of detection FBGs 120, and a signal receiving and processing unit 130; each detection FBG 120 is inscribed on the optical fiber 110 at a certain interval, and each detection FBG 120 is coated with a single gas-sensitive material; the signal receiving and processing unit 130 receives the reflected light signals of each detection FBG 120 scanned by an external light source 140; the reflected spectrum peak shift of the reflected light signals is calculated; and the concentration values of different gas pollutants are calculated according to the reflected spectrum peak shift.

[0029] The optical fiber 110 is the basic carrier of the entire sensing assembly and is used for transmitting optical signals. In the present embodiment, a single-mode optical fiber is selected, which has the advantages of low loss and high bandwidth, and can ensure the stability and accuracy of the optical signals in the transmission process.

[0030] The FBG is an optical device made by forming a periodic refractive index modulation in the core of an optical fiber, which can reflect light of a specific wavelength. Its working principle is based on the Bragg diffraction effect. When light propagates in the optical fiber, light waves that satisfy the Bragg condition (i.e., the wavelength of light and the grating period satisfy a certain relationship) will be reflected back, while light waves that do not satisfy the condition will continue to propagate forward. In optical fiber sensing, when the external environmental factors (such as temperature, strain, gas concentration, etc.) change, the refractive index modulation period or effective refractive index of the FBG will change, causing the wavelength of the reflected light to shift. By detecting this wavelength shift, the environmental parameters can be measured. In the present application, each detection FBG 120 corresponds to an independent sensor unit for detecting different gas pollutants. Each detection FBG 120 is coated with a single gas-sensitive material. Gas-sensitive material is a material that has a sensitive response to a specific gas. When it comes into contact with the target gas, its physical or chemical properties will change, thereby affecting the optical properties of the FBG. For example, for a detection FBG 120 that detects sulfur dioxide (SO2), the gas-sensitive material coated can be a metal oxide semiconductor material with SO2 adsorption and reaction characteristics, such as tin oxide (SnO2). When there is SO2 gas in the environment, SO2 molecules will adsorb on the surface of the gas-sensitive material, causing changes in the resistivity and other physical properties of the gas-sensitive material, thereby causing changes in the refractive index and other optical parameters of the FBG. Each detection FBG 120 is inscribed on the optical fiber 110 at a certain interval, which is to avoid the mutual interference of optical signals between adjacent FBGs. The size of the interval can be designed according to actual needs, and is generally controlled between a few centimeters to a few tens of centimeters. Further, these FBGs can be inscribed on the optical fiber 110 at equal intervals. For example, in the present embodiment, the interval between adjacent detection FBGs 120 can be 10 cm, which can ensure the independent operation of each FBG and also will not make the optical fiber 110 too long to increase the cost and installation difficulty.

[0031] The signal receiving and processing unit 130 is the core control part of the whole sensing assembly, which is responsible for receiving the reflected light signals of each detection FBG 120 scanned by the external light source respectively, and processing and analyzing these signals. In practical application, the external light source module generates a broadband light signal and couples it into the optical fiber 110. When the light signal is transmitted in the optical fiber 110, it will pass through each detection FBG 120 in turn. Each detection FBG 120 has a reflection effect on light of a specific wavelength, and when the wavelength of the light signal matches the Bragg wavelength of the FBG, the light of that wavelength will be reflected back by the FBG. Because the Bragg wavelengths of different detection FBGs 120 are different, they will reflect light signals of different wavelengths respectively. The reflected light signal returns to the signal receiving and processing unit 130 along the optical fiber 110, and the signal receiving and processing unit 130 can analyze the received electrical signal and draw a reflection spectrum curve. In the absence of gas pollutants, the reflection spectrum peak position of each detection FBG 120 is fixed. When the target gas pollutants exist in the environment, the gas-sensitive material coated on the detection FBG 120 will react with the gas, causing the optical properties of the FBG to change, thereby causing the reflection spectrum peak position to shift. The signal receiving and processing unit 130 calculates the reflection spectrum peak shift by comparing the current reflection spectrum peak position with the initial peak position, and then calculates the concentration values of different gas pollutants based on the reflection spectrum peak shift and the sensitivity of the gas-sensitive material.

[0032] The above multi-parameter optical fiber sensing assembly includes an optical fiber 110, a plurality of detection FBGs 120, and a signal receiving and processing unit 130; each detection FBG 120 is spaced apart and written on the optical fiber 110, and each detection FBG 120 is coated with a single gas-sensitive material; the signal receiving and processing unit 130 receives the reflected light signals of each detection FBG 120 scanned by the external light source 140; calculates the reflection spectrum peak shift corresponding to the reflected light signal; and calculates the concentration values of different gas pollutants according to the reflection spectrum peak shift. The whole assembly writes a plurality of detection FBGs coated with a single gas-sensitive material on the same optical fiber 110, and calculates the concentration values of different gas pollutants according to the reflection spectrum peak shift by the signal receiving and processing unit 130, which has a simple overall structure and realizes the high integration of the multi-gas pollutant detection function.

[0033] In one embodiment, as shown in Figure 2 The above multi-parameter optical fiber sensing assembly further includes a light source 140, which is used to scan each detection FBG 120 in a time division multiplexing manner.

[0034] In the embodiment, the light source 140 is used to scan each detection FBG 120 respectively by using time division multiplexing. The light source 140 is a single broadband light source. Specifically, time division multiplexing is a technical means for efficiently using the light source 140. In the specific work, the light source 140 emits light signals into the optical fiber 110 in a predetermined time sequence, and each time the emitted light signal is only for one detection FBG 120. For example, in the first time interval (time window), the light source 140 emits light signals of a specific wavelength range, which can excite the first detection FBG 120 to generate reflection; in the second time interval (time window), the light source 140 adjusts the parameters of the emitted light signal so that it can excite the second detection FBG 120 to generate reflection, and so on. In this way, the signal confusion problem caused by the simultaneous reflection of multiple FBGs is avoided, and the accuracy and reliability of the detection are improved.

[0035] Further, the light source 140 is a single-wavelength light source 140, and the single wavelength is any value in the range of 400nm-10000nm. In the embodiment, the light source 140 is a fixed single-wavelength light source, that is, the light source 140 only emits light signals of a fixed wavelength. Specifically, a light source corresponding to any single wavelength in the range of 400nm-10000nm can be selected, for example, a 600nm wavelength light source, a 1000nm wavelength light source. Preferably, a 1550nm wavelength light source can be selected.

[0036] In one of the embodiments, as shown in Figure 2 The above multi-parameter optical fiber sensing assembly further includes a circulator 150, and the light source 140 guides the irradiation of each detection FBG 120 through the circulator 150.

[0037] In the embodiment, the multi-parameter optical fiber sensing assembly further includes a circulator 150, one end of the circulator 150 is connected with the light source 140, and one end of the circulator 150 is connected with the signal receiving and processing unit 130. The light emitted by the light source 140 irradiates each detection FBG 120 through the circulator 150 Figure 2 The structure is a schematic diagram, and the optical path is not shown), and the reflected light signal of each detection FBG 120 can be reflected back into the signal receiving and processing unit 130 through the circulator 150. Specifically, the circulator 150 can guide the light signal to be reflected or circulated multiple times, thereby improving the sensitivity and measurement accuracy of the sensor.

[0038] In one of the embodiments, as shown in Figure 2As shown, the multi-parameter optical fiber sensing assembly further comprises a reference FBG 160 inscribed in the optical fiber 110, and the reference FBG 160 is not coated with the gas sensitive material; the signal receiving and processing unit 130 is further configured to collect a reference reflected light signal of the reference FBG 160 scanned by the external light source 140, and to denoise the reflected light signal of each detection FBG 120 scanned by the external light source 140 according to the reference reflected light signal.

[0039] In the multi-parameter optical fiber sensing assembly of the present embodiment, a reference FBG inscribed in the optical fiber 110 is added. The reference FBG, like the detection FBGs, is an optical device made by forming a periodic refractive index modulation in the core of the optical fiber 110, and is capable of reflecting light of a specific wavelength. However, unlike the detection FBGs, the reference FBG is not coated with the gas sensitive material. This means that the reference FBG will not react with the target gas pollutants, and its optical properties are mainly affected by environmental factors (such as temperature and humidity, vibration, etc.). The signal receiving and processing unit 130 collects a reference reflected light signal of the reference FBG scanned by the external light source 140 and a reflected light signal of each detection FBG scanned by the external light source 140, respectively. When the light signal irradiates the reference FBG, the reference FBG will reflect the light signal of a specific wavelength, and the reflected light signal contains information about the change in optical properties caused by environmental noise; when the light signal irradiates the detection FBG 120, the detection FBG 120 will not only be affected by environmental noise, but also by the reaction with the target gas pollutants, causing changes in optical properties, and its reflected light signal contains double information about the changes in optical properties caused by environmental noise and gas pollutants. Specifically, the present embodiment uses the reference FBG 160 to achieve common-mode noise cancellation. Common-mode noise refers to environmental noise that simultaneously acts on the reference FBG 160 and the detection FBG 120, such as noise caused by changes in temperature and humidity, vibration, etc. Since the reference FBG 160 and the detection FBG 120 are in the same environmental conditions, they are similarly affected by common-mode noise. By collecting the reference reflected light signal of the reference FBG 160, information about the change in optical properties caused by environmental noise can be obtained, and then this information is used to process the reflected light signal of the detection FBG 120, thereby eliminating common-mode noise.

[0040] In one of the embodiments, as shown in Figure 3 The multi-parameter optical fiber sensing assembly further comprises an insulating sleeve, and the insulating sleeve is sleeved on the optical fiber.

[0041] In the multi-parameter optical fiber sensing assembly of the embodiment, an insulating sleeve is newly added, which tightly sheaths the optical fiber and completely encapsulates the optical fiber part containing multiple detection FBGs. This encapsulation forms a relatively independent physical space between the optical fiber and the external environment, playing a role of physical isolation. Further, the insulating sleeve can be a silica gel sleeve with air holes. The air holes are designed with careful consideration, which can not only ensure that external gas can freely enter the sleeve, so that the detection FBGs on the optical fiber can fully contact the target gas, thereby realizing accurate gas detection function, but also can block the entry of dust and impurities in the external environment to some extent, reducing the pollution and damage to the optical fiber and the detection FBGs. The size and distribution density of the air holes can be adjusted according to actual needs, for example, in some scenes with high requirements for gas circulation, the size of the air holes or the distribution density thereof can be appropriately increased; while in scenes with high dustproof requirements, the size of the air holes or the distribution density thereof can be reduced.

[0042] Overall, in the embodiment, by adding the silica gel insulating sleeve with air holes, the multi-parameter optical fiber sensing assembly of the embodiment forms a passive noise reduction cavity, effectively physically isolates external mechanical interference, does not need to use active filtering algorithm, improves the anti-interference ability and measurement accuracy of the sensor, and has broad application prospects in various actual application scenarios.

[0043] In one of the embodiments, the signal receiving and processing unit is further configured to obtain an initial reflection peak wavelength of the current detection FBG in an environment with a known concentration; calculate an actual reflection peak wavelength of the current detection FBG in the current environment to be measured according to the reflected light signal; calculate a reflection spectrum peak value shift amount according to the initial reflection peak wavelength and the actual reflection peak wavelength; obtain a sensitivity corresponding to the gas-sensitive material coated on the current detection FBG, and calculate the concentration of the gas pollutant detected by the current detection FBG according to the reflection spectrum peak value shift amount and the sensitivity.

[0044] The current detection FBG refers to the corresponding detection FBG being processed by the current signal receiving and processing unit, and any one of the multiple detection FBGs can become the current detection FBG. After the signal receiving and processing unit finishes processing the current detection FBG, the next detection FBG can be re-designated as the current detection FBG, and a new round of calculation and processing can be started.

[0045] Specifically, before the multi-parameter optical fiber sensing assembly is actually applied, the initial reflection peak wavelength λ0of the current FBG in a gas-free or known concentration environment needs to be obtained. In specific operation, the sensing assembly can be placed in a specific environment, such as a sealed container filled with high-purity nitrogen gas (regarded as no target gas) or a standard gas environment with a known target gas concentration. The reflection light signal of the current FBG is collected by using a signal receiving and processing unit, and the initial reflection peak wavelength λ0is extracted by built-in algorithm and software processing, which is used as a reference for subsequent calculation. The multi-parameter optical fiber sensing assembly is placed in the current environment to be measured, which may contain target gas pollutants, such as sulfur dioxide in industrial production workshops or carbon monoxide in urban air. The signal receiving and processing unit continuously collects the reflection light signal of the current FBG in the environment to be measured. Due to the reaction between the target gas and the gas-sensitive material coated on the current FBG, the optical properties of the current FBG change, and the reflection peak wavelength shifts. Through the same algorithm and software processing as obtaining the initial reflection peak wavelength, the actual reflection peak wavelength λ of the current FBG in the environment to be measured is calculated. Based on the obtained initial reflection peak wavelength λ0and the actual reflection peak wavelength λ, the signal receiving and processing unit calculates the reflection spectrum peak shift Δλ. According to the formula Δλ = λ - λ0, the shift reflects the degree of change in optical properties caused by the reaction between the target gas and the gas-sensitive material, which is a key parameter for calculating the gas concentration. Specifically, the sensitivity S of the current FBG coated with gas-sensitive material corresponding to a unit gas concentration change can be determined in advance through experiments, and the unit is usually nm / ppm. According to the formula c = Δλ / S, the signal receiving and processing unit calculates the concentration c of the gas pollutant detected by the current FBG according to the reflection spectrum peak shift Δλ and the known sensitivity S. Taking the detection of indoor formaldehyde concentration as an example, the initial reflection peak wavelength λ0of the current FBG is obtained in a formaldehyde-free environment (such as an air environment treated by professional purification). Then the sensing assembly is placed in the indoor environment to be measured, the reflection light signal of the current FBG in the indoor air is collected, and the actual reflection peak wavelength λ is obtained. The reflection spectrum peak shift Δλ = λ - λ0is calculated, and then the indoor formaldehyde concentration c is calculated by the formula c = Δλ / S combined with the known sensitivity S of the current FBG coated with gas-sensitive material to formaldehyde.

[0046] As shown in Figure 4 The present application also provides an air purification device, which comprises a multi-parameter optical fiber sensing assembly 410 as described above, an air purification assembly 420 and a controller 430.

[0047] The multi-parameter optical fiber sensing assembly 410 and the air purification assembly 420 are respectively connected with the controller 430.

[0048] The multi-parameter optical fiber sensing assembly 410 is configured to detect the concentrations of different types of gas pollutants in the air and send the detection results to the controller 430. The air purification assembly 420 is configured to perform air purification operations under the control of the controller 430. Specifically, the air purification assembly 420 can include a plurality of purification units, and different purification units are configured to perform purification operations on different types of gas pollutants. The controller 430 is configured to receive the concentrations of different types of gas pollutants, compare the concentrations of different types of gas pollutants with preset concentration thresholds, identify target gas pollutants with concentrations exceeding the thresholds, and then control the air purification assembly 420 to perform purification operations on the target gas pollutants.

[0049] The air purification device includes the multi-parameter optical fiber sensing assembly 410, the air purification assembly 420, and the controller 430. The multi-parameter optical fiber sensing assembly 410 writes a plurality of detection FBG spacings coated with a single gas-sensitive material on the same optical fiber, and a signal receiving and processing unit is configured to calculate the concentration values of different gas pollutants based on the reflection spectrum peak shift. The air purification device has a simple overall structure and realizes high integration of the multi-gas pollutant detection function. The controller 430 controls the air purification assembly 420 to perform purification operations based on the concentration values of different gas pollutants detected by the multi-parameter optical fiber sensing assembly 410. The air purification device has high integration and a simple structure.

[0050] In one embodiment, the air purification assembly 420 includes a plurality of purification units, and each purification unit is configured to perform purification operations on different types of gas pollutants.

[0051] The controller is further configured to receive the concentration values of different gas pollutants fed back by the multi-parameter optical fiber sensing assembly, compare the concentration values of different gas pollutants with preset concentration thresholds of each gas pollutant, identify target gas pollutants with concentrations exceeding the thresholds, and control the purification units corresponding to the target gas pollutants in the air purification assembly to be activated.

[0052] In this embodiment, the air purification assembly includes a plurality of purification units, and each purification unit is configured to purify different gas pollutants. Specifically, it can include a HEPA (High Efficiency Particulate Air Filter) filter and activated carbon. The controller can have different gas pollutant concentration thresholds pre-stored and compared with the actual detection values to identify target gas pollutants with concentrations exceeding the thresholds, and then activate the corresponding purification units to perform targeted purification operations. It should be noted that if the concentrations of multiple types of gas pollutants exceed the thresholds, multiple purification units will be activated to perform purification operations.

[0053] In one of the embodiments, the air purification device further comprises a fan connected with the controller, and the controller is further configured to receive the different gas pollutant concentration values fed back by the multi-parameter optical fiber sensing assembly, identify the pollution level according to the different gas pollutant concentration values, and adjust the rotating speed of the fan based on the pollution level.

[0054] In the embodiment, the air purification device further comprises a fan, and the fan can be provided with multiple rotating speed levels. The controller is pre-stored with the pollutant concentration values corresponding to different pollution levels. In actual application, the controller receives the different gas pollutant concentration values fed back by the multi-parameter optical fiber sensing assembly, identifies the pollution level according to the different gas pollutant concentration values and the pollutant concentration values corresponding to different pollution levels, and then adjusts the rotating speed of the fan according to the pollution level. In actual application, the rotating speed of the fan is divided into three levels according to the pollution level, and the rotating speed of the direct-current brushless motor is adjusted by a PWM (Pulse Width Modulation) signal.

[0055] Further, the air purification device further comprises an indicator light connected with the controller, and the indicator light is configured to display different pollution levels. The indicator light can be an LED indicator light, which specifically displays yellow, green and red.

[0056] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present disclosure.

[0057] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as the limitation of the patent scope of the present application. It should be pointed out that, for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A multi-parameter optical fiber sensing component, characterized in that: It includes optical fiber, multiple detection FBGs, and a signal receiving and processing unit; The detection FBGs are respectively inscribed on the optical fiber at intervals, and each detection FBG is coated with a single gas-sensitive material; The signal receiving and processing unit receives the reflected light signals of the external light source and scans each of the detection FBGs respectively; calculates the reflected spectrum peak offset corresponding to the reflected light signal; and calculates the concentration values ​​of different gas pollutants according to the reflected spectrum peak offset.

2. The multi-parameter optical fiber sensing assembly according to claim 1, characterized in that: It also includes a light source, which is used to scan each of the detection FBGs separately in a time-division multiplexing manner.

3. The multi-parameter optical fiber sensing assembly according to claim 2, characterized in that: The light source is a single wavelength light source, and the single wavelength is any value between 400nm and 10000nm.

4. The multi-parameter optical fiber sensing assembly according to claim 2 or 3, characterized in that: A circulator is further included, through which the light source is guided to illuminate each of the detection FBGs.

5. The multi-parameter optical fiber sensing assembly according to claim 1, characterized in that: Also included is a reference FBG inscribed on the optical fiber, wherein the reference FBG is not coated with the gas-sensitive material; The signal receiving and processing unit is further configured to collect a reference reflected light signal of an external light source scanning the reference FBG, and perform denoising on the reflected light signal of the external light source scanning each detection FBG according to the reference reflected light signal.

6. The multi-parameter optical fiber sensing assembly according to claim 1, characterized in that: It also includes an insulating sleeve, which is externally mounted on the optical fiber.

7. The multi-parameter optical fiber sensing assembly according to claim 1, characterized in that: The signal receiving and processing unit is further configured to obtain an initial reflection peak wavelength of the current detection FBG in an environment with a known concentration; and calculate an actual reflection peak wavelength of the current detection FBG in the current environment to be tested based on the reflected light signal. Calculating a reflection spectrum peak shift according to the initial reflection peak wavelength and the actual reflection peak wavelength; The sensitivity corresponding to the gas-sensitive material coated on the current detection FBG is obtained, and the concentration of the gas pollutant detected by the current detection FBG is calculated based on the reflection spectrum peak shift and the sensitivity.

8. An air purification device, characterized in that: Comprising the multi-parameter optical fiber sensing component, air purification component and controller according to any one of claims 1 to 7; The multi-parameter optical fiber sensing component and the air purification component are respectively connected to the controller.

9. The air purification device according to claim 8, characterized in that: The air purification component includes a plurality of purification units, each of which is used to perform purification operations on different types of gaseous pollutants; The controller is also used to receive different gas pollutant concentration values ​​fed back by the multi-parameter optical fiber sensing component; compare the different gas pollutant concentration values ​​with preset gas pollutant concentration thresholds to identify target gas pollutants with excessive concentrations; and control the start-up of the purification unit corresponding to the target gas pollutant in the air purification component.

10. The air purification device according to claim 8, characterized in that: It also includes a fan, which is connected to the controller. The controller is also used to receive different gas pollutant concentration values ​​fed back by the multi-parameter fiber optic sensing component; identify the pollution level according to the different gas pollutant concentration values; and adjust the fan speed based on the pollution level.

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