A method and device for detecting aviation kerosene concentration based on composite sensor

Abstract

The present invention discloses a method and device for detecting aviation kerosene concentration based on a composite sensor, which has the characteristics of high response speed, high sensitivity, low anti-interference and accurate and reliable detection data. A portable warning device for kerosene concentration based on a composite sensor is designed, which includes the following detection steps: step 1, synchronous detection of kerosene concentration by using a sensor detection unit, realizing synchronous detection of kerosene vapor by a semiconductor sensor module and an infrared sensor module; step 2, determination and output of the result of the sensor detection unit by using a composite determination unit, realizing rapid response to kerosene vapor and obtaining high-precision detection data; step 3, the integrated warning unit realizes real-time monitoring and warning of kerosene concentration information through data transmission with the composite determination unit. The present invention integrates composite sensing design and determination technology, and combines the warning unit to realize a portable warning device applied to aviation kerosene transportation channels.

Description

Technical Field

[0001] The invention relates to the technical field of aviation kerosene concentration detection, and in particular to an aviation kerosene concentration detection method and device based on a composite sensor. Background Art

[0002] Aviation kerosene is a petroleum product, mainly composed of hydrocarbon compounds of different fractions. It has suitable density, high calorific value and good combustion performance. It has been widely used in the field of aerospace and can be used as fuel for piston direct injection engines or as an alternative fuel for diesel engines. At the same time, aviation kerosene is a fuel with certain volatility and extremely high combustion calorific value. During storage and transportation, once its vapor and air mixture encounters open flames or certain induced energy, it will easily cause combustion and explosion accidents, resulting in great casualties and property losses. The research on kerosene leakage detection technology is of great significance to the development of aviation industry. Aviation kerosene contains hundreds of components such as alkanes (straight-chain alkanes and branched-chain alkanes), cycloalkanes and aromatic hydrocarbons. The composition is complex. If it is detected by traditional chemical composition, it will take a lot of time and manpower. There are many kinds of consumables for the instrument, resulting in too high cost of data collection and difficulty in timely response to the requirements of aviation kerosene concentration. At the same time, aviation kerosene has an anesthetic and irritating effect on the human body. When inhaled at high concentrations, it manifests as headache, fatigue, and even coma. The detection time should not be too long. In order to better prevent accidents caused by leakage of aviation kerosene during transportation and storage, a new detection method is needed to replace manual detection, while ensuring the timeliness, safety and accuracy of the acquisition of leaked aviation kerosene concentration data.

[0003] The sensor is a high-precision detection instrument with important application value in aviation kerosene detection. Existing solution 1 is to detect the dielectric constant of the oil at the bottom of the fuel tank through a differential capacitive sensor. When a leak occurs, the dielectric constant of the oil will change. This solution is mainly aimed at the leakage of liquid kerosene in the fuel chamber during the flight of the aircraft. It is not suitable for other forms of leakage of kerosene during storage and transportation, and the dielectric constant is affected by temperature. Existing solution 2 is to cause the electrical signal output by the thermal conductivity sensor to change due to the slight change in the concentration of multi-carbon alkanes volatile in the air. The weak signal output by the thermal conductivity sensor is amplified and filtered to the single-chip microcomputer for linearization processing to obtain the corresponding kerosene vapor concentration value. The disadvantage of this solution is that it is easy to produce temperature drift and zero drift, which will affect the accuracy of the entire measurement signal and cause errors in the measurement results. Existing solution 3 is that since kerosene contains propane, the propane concentration in the air is collected through a hydrocarbon sensor. If the collected propane concentration exceeds the preset threshold, it means that a kerosene leak has occurred in the surrounding area. Based on the analysis of sensor principles, it is currently difficult for a single sensor to simultaneously achieve the characteristics of rapid response, high detection sensitivity and anti-interference. In order to detect the concentration of leaked aviation kerosene more accurately and quickly, it is necessary to combine multiple sensors for composite judgment, which can provide accurate measurement data while responding quickly.

[0004] The transportation methods of aviation kerosene usually include railway transportation, road transportation, pipeline transportation, and tanker transportation. Among them, railway transportation and road transportation have become the main transportation methods used by many small domestic airports due to their low investment, flexible and timely transportation, etc. Generally, the population along railways and roads is relatively dense. Once an oil leak occurs, it will cause great casualties and property losses to nearby residential areas and traffic people along the line. Therefore, a aviation kerosene concentration early warning device specifically for railway and road transportation is needed to prevent major accidents. Summary of the invention

[0005] The technology of the present invention solves the problem: Overcoming the shortcomings of the prior art, providing a method and device for detecting aviation kerosene concentration based on a composite sensor, having the advantages of rapid identification and detection, accurate analysis and judgment, and realizing real-time monitoring and graded alarm of aviation kerosene vapor.

[0006] Technical solution of the present invention:

[0007] A method for detecting aviation kerosene concentration based on a composite sensor, comprising the following contents:

[0008] Step 1: Use a sensor detection unit to synchronously detect the concentration of kerosene vapor; the sensor detection unit refers to a semiconductor sensor module and an infrared sensor module; the synchronous detection refers to two different sensor modules synchronously detecting kerosene vapor;

[0009] Step 2: using a composite determination unit to determine and output the result of the sensor detection unit, the composite determination unit realizes the acquisition and composite determination of the sensor signal of the sensor detection unit, realizes a rapid response to the kerosene concentration and gives accurate metering data at the same time;

[0010] Step 3: The integrated warning unit realizes warning through data transmission with the composite determination unit. The integrated warning unit realizes real-time display of kerosene vapor concentration and graded warning. The graded warning refers to different degrees of alarm mode set according to the explosion limit;

[0011] The sensor detection unit includes: a semiconductor sensor module and an infrared sensor module; the semiconductor sensor module is a micro-nano film type gas sensor based on a MEMS micro heater by developing a micro-nano film on a MEMS micro board; when kerosene vapor passes through the semiconductor sensor module, a slight change in the concentration of kerosene vapor causes the resistance value of the micro-nano film type gas sensor to produce a corresponding oscillation, and the resistance value of the sensor is obtained by the oscillation frequency to detect the current kerosene vapor concentration; the infrared sensor module is a gas sensor based on the NDIR infrared absorption principle, including a light source with a significant CH bond absorption effect formulated for kerosene vapor, an optical cavity, a dual-channel detector and a microprocessor; when the light source is absorbed by a certain length of the optical cavity, the gas sensor based on the NDIR infrared absorption principle monitors the intensity of the transmitted light source to indicate the concentration of kerosene vapor, and the microprocessor performs signal acquisition, processing and output, and a built-in temperature sensor is used for temperature compensation, which can further improve the detection accuracy of the sensor.

[0012] The composite determination unit realizes dual-mode composite sensor signal acquisition and composite determination; the dual-mode composite sensor signal acquisition includes: semiconductor sensor module signal acquisition and infrared sensor module signal acquisition.

[0013] The integrated early warning unit includes: a main control chip, an alarm module, an LCD module, and a power supply module; the main control chip selects an ultra-low power consumption microcontroller with an integrated A / D converter and LCD driver to realize data processing of processing unit signals and functional control of other modules; the other modules include a sensor detection unit and a composite judgment unit; the alarm module consists of an LED alarm light, a buzzer, and a vibrator, and has triple alarms of sound, light, and vibration. The electric buzzer adopts a passive buzzer, and the vibrator adopts a small button vibrator; the LCD module includes a key module and a backlight detection module. The key module realizes multiple functions in different working states, and the backlight detection module is responsible for detecting the ambient light intensity; the power supply module adopts a lithium battery, which is responsible for continuously supplying power to each module, and each module includes an alarm module, an LCD module, and a power supply module.

[0014] In step 2 and step 3, the composite determination unit also obtains the signal data of the sensor detection unit for composite determination, and implements graded warning by data transmission between the composite determination unit and the integrated warning unit; the signal data includes signal data of the semiconductor sensor module and the infrared sensor module.

[0015] In step 1, the process of synchronously detecting the kerosene concentration using the sensor detection unit is as follows:

[0016] (1) Semiconductor sensor module detection process: The semiconductor sensor consists of a heater and a MEMS sensor. The heater is modeled as a resistor, which increases the temperature by the current flowing through it and the dissipated power. Once the heater is provided with a heating voltage to a set high-temperature working environment, when the kerosene vapor concentration in the environment changes, the oscillation principle is used to make the resistance value of the gas sensor produce corresponding oscillations, and the resistance value of the sensor and the kerosene vapor concentration at this time are obtained through the oscillation frequency.

[0017] (2) Infrared sensor module detection process: The gas sensor based on the NDIR infrared absorption principle uses a light source with a significant absorption effect on the CH bond. After passing through an optical cavity of a certain length for absorption and a filter, the intensity of the infrared light passing through the filter is monitored by a dual-channel infrared detector. The microprocessor collects and processes the signal and finally outputs the kerosene vapor concentration.

[0018] In step 2, the process of using the composite determination unit to determine and output the result of the sensor detection unit is as follows:

[0019] First, the sensor detection unit is used to collect signals, and then the collected data is compositely judged and outputted through the processing circuit in the composite judgment unit. The signal collection includes semiconductor sensor module signals and infrared sensor module signals.

[0020] In step 3, the early warning is realized by data transmission between the composite determination unit and the integrated early warning unit as follows:

[0021] The signal output by the composite judgment detection unit is amplified by the sensor signal acquisition and amplification module of the integrated early warning unit and transmitted to the main control chip for AD conversion; the main control chip converts the AD value into kerosene vapor concentration and displays it in real time on the LCD module, and then compares the converted kerosene vapor concentration with the first-level early warning threshold and the second-level early warning threshold, and controls the buzzer, vibrator, and LED alarm light through the I / O port of the main control chip.

[0022] The LCD module can display the concentration of kerosene vapor in real time, and has multiple icons such as buzzer, vibrator, and LED alarm light to display the current working status, including a key module and a backlight detection module. The key module can realize multiple functions by scanning the length of time the key is pressed in conjunction with the current working status; the backlight detection module is mainly responsible for detecting the intensity of ambient light, and is composed of a photosensitive element and a resistor. The photosensitive element converts the light intensity in the environment into an electrical signal, which is amplified by a resistor and then converted by the main control chip. The intensity of the ambient light is judged by comparing with the threshold value, and the backlight is quickly lit according to the output of the key module or the alarm module in weak light, and the backlight is automatically turned off in strong light. The buzzer adopts a passive buzzer, which can emit high, medium, and low sounds to realize graded alarms of different tones; the vibrator adopts a small button vibrator; and the LED alarm light can emit red and yellow light.

[0023] The threshold of the first-level warning and the threshold of the second-level warning are set according to the lower explosion limit (LEL) of kerosene vapor, the threshold of the first-level warning is set to 25%LEL, and the threshold of the second-level warning is set to 50%LEL; the first-level warning adopts the LED alarm light and buzzer to jointly alarm, the LED alarm light flashes yellow, and the buzzer emits a medium tone; the second-level warning adopts the LED alarm light, buzzer, and vibrator to jointly alarm, the LED alarm light flashes red, the buzzer emits a high tone, and the vibrator vibrates continuously, and the alarm can be stopped by the button module.

[0024] In the mixing chamber, kerosene vapor is filled from low to high concentration, and an ignition experiment is performed. The average value Li of the maximum kerosene vapor concentration before explosion and the minimum kerosene vapor concentration when explosion occurs detected by the integrated detection unit and the composite judgment unit is taken, i represents the number of experiments, and the ignition experiment is repeated and each Li (L1, L2, L3...Ln) is recorded. After n experiments, the lower explosion limit LEL is (L1+l2+...Ln) / n. The process of the ignition experiment is:

[0025] First, add a certain amount of aviation kerosene to the gas generating device, and then heat it outside the launching device to generate some steam. Through the method of partial pressure distribution, the kerosene steam in the gas generating device is respectively rushed into the mixing chamber and the shock tube. Then, the valve is opened to let in a certain amount of air. The circulating pump is turned on for 20 minutes to make the gas in the mixing chamber and the shock tube evenly mixed. The igniter is connected to the shock tube to carry out ignition and detonation experiments, and the kerosene concentration data in the mixing chamber is detected by the integrated detection unit and the composite judgment unit.

[0026] The present invention proposes a sensor-based aviation kerosene concentration detection device, which performs composite judgment by a sensor detection unit and a composite judgment unit, and provides accurate concentration data while realizing rapid response in combination with transmission of an integrated early warning unit, and designs a portable device for real-time monitoring and early warning in channels for aviation kerosene transportation; the channels for aviation kerosene transportation include transportation tools such as railways, highways, pipelines, and cruise ships.

[0027] The sensor detection unit includes: a semiconductor sensor module and an infrared sensor module; the semiconductor sensor module is a micro-nano film type gas sensor based on a MEMS micro heater by developing a micro-nano film on a MEMS micro board; the infrared sensor module is a gas sensor based on the NDIR infrared absorption principle, and is composed of a light source with obvious CH bond absorption effect, an optical cavity, a dual-channel detector, a narrow-band filter and a microprocessor.

[0028] The composite determination unit realizes dual-mode composite sensor signal acquisition and composite determination; the dual-mode composite sensor signal acquisition includes: semiconductor sensor module signal acquisition and infrared sensor module signal acquisition.

[0029] The integrated early warning unit includes: a sensor signal acquisition and amplification module, a main control chip, an alarm module, an LCD module, and a power supply module; the main control chip selects an ultra-low power consumption microcontroller, which integrates an A / D converter, a timer, a serial port module, and an LCD driver to realize data processing of the processing unit signal and functional control of other modules. The other modules include a sensor signal acquisition and amplification module, a composite judgment unit, and an alarm module; the alarm module consists of an LED alarm light, a buzzer, and a vibrator, and has triple alarms of sound, light, and vibration. The electric buzzer adopts a passive buzzer, and the vibrator adopts a small button vibrator; the LCD module includes a key module and a backlight detection module. The key module realizes multiple functions in different working states, and the backlight detection module is responsible for detecting the ambient light intensity; the power module adopts a lithium battery to continuously supply power to each module.

[0030] The advantages of the present invention compared with the prior art are:

[0031] (1) The present invention utilizes a sensor detection unit to detect kerosene vapor. The semiconductor sensor module in the sensor detection unit has the advantages of high sensitivity and fast response time by developing a micro-nano film on a MEMS micro-plate, and is suitable for integrated use in a small volume. At the same time, the sensor based on the MEMS micro-heater has a faster heating speed than the traditional sensor, and the power consumption is greatly reduced. The gas sensor module in the sensor detection unit uses the NDIR infrared absorption principle, and a light source with obvious CH bond absorption effect customized for kerosene vapor is formulated. At the same time, dual-channel detection is used to realize spatial dual-optical path reference compensation. While eliminating detection interference, a built-in temperature sensor can perform temperature compensation, thereby further improving the detection accuracy of the sensor.

[0032] (2) The present invention utilizes a composite determination unit to determine and output the results of the sensor detection unit. The sensor detection unit adopts an independent working and information composite processing working mode. The semiconductor and infrared sensors work separately and synchronously. The signal output by the composite determination unit has both high timeliness and high accuracy.

[0033] (3) The present invention can realize graded warning of kerosene vapor concentration by combining a composite judgment unit with an integrated warning unit, and designs a portable warning device based on this technology. The device is small in size, light in weight, wearable or handheld, and has high sensitivity, which can realize fast and accurate real-time monitoring and warning of kerosene concentration, and has important application value for the detection of aviation kerosene concentration in road and rail transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the composition of the sensor detection unit of the present invention;

[0035] Figure 2 This is a schematic diagram of the working mode of the composite determination unit of the present invention;

[0036] Figure 3 The schematic diagram of the portable detector for aviation kerosene concentration based on the composite sensor of the present invention is shown in FIG.

[0037] Figure 4 The present invention is a detection flow chart of the portable detector for aviation kerosene concentration based on a composite sensor. DETAILED DESCRIPTION

[0038] The present invention is further described below with reference to the accompanying drawings and specific embodiments.

[0039] like Figure 1As shown, the sensor detection unit includes: a semiconductor sensor module and an infrared sensor module; the semiconductor sensor module is formed by developing a micro-nano film on a MEMS micro-board, based on the entire silicon substrate, and consists of a heater and a sensor surface sensitive material; the infrared gas sensor is used to achieve high-precision measurement detection while eliminating detection interference. The sensor uses a gas sensor module based on the NDIR infrared absorption principle, and customizes a light source, optical cavity and dual-channel detector with obvious CH bond absorption effect for kerosene vapor to achieve spatial dual-optical path reference compensation. The microprocessor performs signal acquisition, processing and output, and a built-in temperature sensor can perform temperature compensation to further improve the detection accuracy of the sensor.

[0040] like Figure 2 As shown, the process of synchronous detection of kerosene vapor by the semiconductor sensor module and the infrared sensor module in the sensor detection unit is as follows:

[0041] (1) Semiconductor sensor module detection process: The semiconductor sensor consists of a heater and a sensitive material on the sensor surface. The heater is modeled as a small resistor, which increases the temperature by passing a large amount of current and dissipating the necessary power. Once the heater resistor is provided with a certain high-temperature working environment through the heating voltage, the kerosene vapor changes the sensor's own resistance through the adsorption and desorption principle of the sensitive material. When the kerosene vapor concentration in the environment changes, the sensor's resistance value also changes accordingly. The kerosene vapor concentration at this time can be detected based on the resistance value.

[0042] (2) Infrared sensor module detection process: The light source uses a light source with a significant absorption effect on the CH bond. After passing through an optical cavity of a certain length for absorption and a filter, the intensity of the infrared light passing through the filter is monitored by a dual-channel infrared detector. The microprocessor collects and processes the signal and finally outputs the kerosene vapor concentration.

[0043] The composite determination unit first collects signals from the sensor detection unit, and then performs composite determination and output on the collected data through the processing circuit in the composite determination unit. The signal acquisition includes semiconductor sensor module signals and infrared sensor module signals. The semiconductor sensor module has the advantages of short response time and high sensitivity, and the infrared sensor module has the advantages of high detection accuracy and strong anti-interference ability. The output after composite determination has the advantages of both sensor modules.

[0044] like Figure 3As shown, the portable detector for aviation kerosene concentration based on a composite sensor of the present invention is composed of three parts: a sensor detection unit, a composite determination unit and an integrated early warning unit. The integrated early warning unit includes: a main control chip, an alarm module, an LCD module, and a power supply module; the main control chip selects an ultra-low power consumption microcontroller with an internal integrated A / D converter, a timer, a serial port module, and an LCD driver to realize data processing of the processing unit signal and functional control of other modules, and the other modules include a sensor signal acquisition and amplification module, a composite judgment unit, and an alarm module; the alarm module is composed of an LED alarm light, a buzzer, and a vibrator, and has triple alarms of sound, light, and vibration. The electric buzzer adopts a passive buzzer, and the vibrator adopts a small button vibrator; the LCD realizes real-time display of kerosene vapor concentration, and has multiple icons of a buzzer, a vibrator, and an LED alarm light to display the current working status, including a key module and a backlight detection module. The key module realizes multiple functions by scanning the length of time the key is pressed in conjunction with the current working status; the backlight detection module is mainly responsible for detecting the intensity of ambient light, and is composed of a photosensitive element and a resistor; the power supply module adopts a lithium battery, which is responsible for continuously supplying power to each module, and the modules include an alarm module, an LCD module, and a power supply module.

[0045] like Figure 4 As shown, the detection process of the portable detector of aviation kerosene concentration based on the composite sensor of the present invention includes:

[0046] System initialization. System initialization refers to the initialization of preset parameters, including the initialization of the warning threshold and the backlight brightness threshold. The warning threshold is set by the lower explosion limit (LEL) of kerosene vapor. The threshold of the first warning is set to 25%LEL, and the threshold of the first warning is set to 50%LEL. The backlight brightness threshold is set manually.

[0047] Equipment self-test: Equipment self-test refers to judging whether the sensor detection unit is working properly.

[0048] Sensor composite detection. Sensor composite detection means that the kerosene vapor passes through the infrared sensor and the semiconductor sensor respectively, and the two sensors detect the concentration of kerosene vapor at the same time.

[0049] Composite judgment display. The processing circuit in the composite judgment unit performs composite judgment on the signals of the infrared sensor and the semiconductor sensor module, and collects the concentration value of the composite judged kerosene vapor and displays it in real time on the LCD screen.

[0050] Threshold determination. Compare the result of the composite determination with the initial warning threshold. If the result of the composite determination is greater than or equal to 50% LEL, a second-level alarm is issued. The second-level alarm uses a combined alarm of an LED alarm light, a buzzer, and a vibrator. The LED alarm light flashes red, the buzzer emits a high tone, and the vibrator vibrates continuously. The alarm can be stopped by the key module. If the result of the composite determination is less than 50% LEL and greater than or equal to 25% LEL, a first-level alarm is issued. The first-level alarm uses a combined alarm of an LED alarm light and a buzzer. The LED alarm light flashes yellow, the buzzer emits a medium tone, and the alarm can be stopped by the key module.

Claims

1. A method for detecting aviation kerosene concentration based on a composite sensor, characterized in that: The following steps are involved: Step 1: Use a sensor detection unit to synchronously detect the concentration of kerosene vapor; the sensor detection unit refers to a semiconductor sensor module and an infrared sensor module; the synchronous detection refers to two different sensor modules synchronously detecting kerosene vapor; Step 2: using a composite determination unit to determine and output the result of the sensor detection unit, the composite determination unit realizes the acquisition and composite determination of the sensor signal of the sensor detection unit, realizes a rapid response to the kerosene concentration and gives accurate metering data at the same time; Step 3: The integrated warning unit realizes warning through data transmission with the composite determination unit. The integrated warning unit realizes real-time display of kerosene vapor concentration and graded warning. The graded warning refers to different degrees of alarm mode set according to the explosion limit; The sensor detection unit includes: a semiconductor sensor module and an infrared sensor module; the semiconductor sensor module is a micro-nano film type gas sensor based on a MEMS micro heater by developing a micro-nano film on a MEMS micro board. When kerosene vapor passes through the semiconductor sensor module, a slight change in the concentration of kerosene vapor causes the resistance value of the micro-nano film type gas sensor to produce a corresponding oscillation, and the resistance value of the sensor is obtained by the oscillation frequency to detect the current kerosene vapor concentration; the infrared sensor module is a gas sensor based on the NDIR infrared absorption principle, including a light source with a significant CH bond absorption effect formulated for kerosene vapor, an optical cavity, a dual-channel detector and a microprocessor. When the light source is absorbed by a certain length of the optical cavity, the gas sensor based on the NDIR infrared absorption principle monitors the intensity of the transmitted light source to indicate the concentration of kerosene vapor, and the microprocessor performs signal acquisition, processing and output, and a built-in temperature sensor is also provided to perform temperature compensation to improve the detection accuracy of the sensor; The composite determination unit realizes dual-mode composite sensor signal acquisition and composite determination; the dual-mode composite sensor signal acquisition includes: semiconductor sensor module signal acquisition and infrared sensor module signal acquisition; The integrated early warning unit includes: a main control chip, an alarm module, an LCD module, and a power supply module; the main control chip adopts a microcontroller with an integrated A / D converter and LCD driver to realize data processing of processing unit signals and functional control of other modules; the alarm module is composed of an LED alarm light, a buzzer, and a vibrator, and has triple alarms of sound, light, and vibration. The electric buzzer adopts a passive buzzer, and the vibrator adopts a button vibrator; the LCD module includes a key module and a backlight detection module. The key module realizes multiple functions in different working states, and the backlight detection module is responsible for detecting the ambient light intensity; the power supply module adopts a lithium battery, which is responsible for continuously supplying power to the alarm module and the LCD module.

2. The method for detecting aviation kerosene concentration based on a composite sensor according to claim 1, characterized in that: In step 2 and step 3, the composite determination unit also obtains the signal data of the sensor detection unit for composite determination, and implements graded warning by data transmission between the composite determination unit and the integrated warning unit; the signal data includes signal data of the semiconductor sensor module and the infrared sensor module.

3. The method for detecting aviation kerosene concentration based on a composite sensor according to claim 1, characterized in that: In step 1, the process of synchronously detecting the kerosene concentration using the sensor detection unit is as follows: (1) Semiconductor sensor module detection process: The semiconductor sensor consists of a heater and a MEMS sensor. The heater is modeled as a resistor, which increases the temperature through the current flowing through it and the dissipated power. Once the heater is provided with a heating voltage to a set high-temperature working environment, when the kerosene vapor concentration in the environment changes, the oscillation principle is used to make the resistance value of the gas sensor produce corresponding oscillations, and the resistance value of the sensor and the kerosene vapor concentration at this time are obtained through the oscillation frequency; (2) Infrared sensor module detection process: The gas sensor based on the NDIR infrared absorption principle uses a light source with a significant absorption effect on the CH bond. After passing through an optical cavity of a certain length for absorption and a filter, the intensity of the infrared light passing through the filter is monitored by a dual-channel infrared detector. The microprocessor collects and processes the signal and finally outputs the kerosene vapor concentration.

4. The method for detecting aviation kerosene concentration based on a composite sensor according to claim 1, characterized in that: In step 2, the process of using the composite determination unit to determine and output the result of the sensor detection unit is as follows: First, the sensor detection unit is used to collect signals, and then the collected data is compositely judged and outputted through the processing circuit in the composite judgment unit; the signal collection includes semiconductor sensor module signals and infrared sensor module signals.

5. The method for detecting aviation kerosene concentration based on a composite sensor according to claim 1, characterized in that: In step 3, the early warning is realized by data transmission between the composite determination unit and the integrated early warning unit as follows: The signal output by the composite judgment detection unit is amplified by the sensor signal acquisition and amplification module of the integrated early warning unit and transmitted to the main control chip for AD conversion; the main control chip converts the AD value into kerosene vapor concentration and displays it in real time on the LCD module, and then compares the converted kerosene vapor concentration with the first-level early warning threshold and the second-level early warning threshold, and controls the buzzer, vibrator, and LED alarm light through the I / O port of the main control chip.

6. The method for detecting aviation kerosene concentration based on a composite sensor according to claim 5, characterized in that: The LCD module realizes real-time display of kerosene vapor concentration, and has multiple icons such as buzzer, vibrator, LED alarm light to display the current working status, including a key module and a backlight detection module. The key module realizes multiple functions in conjunction with the current working status by scanning the length of time the key is pressed; the backlight detection module is responsible for detecting the intensity of ambient light, and is composed of a photosensitive element and a resistor. The photosensitive element converts the light intensity in the environment into an electrical signal, which is amplified by a resistor and then converted by the main control chip to an AD signal, and the intensity of the ambient light is judged by comparing with the threshold. When the light is weak, that is, lower than the set threshold, the backlight is quickly lit according to the output of the key module or the alarm module, and when the light is strong, that is, higher than or equal to the set threshold, the backlight is automatically turned off; the buzzer adopts a passive buzzer, which emits high, medium and low sounds to realize graded alarms with different tones; the vibrator adopts a button vibrator; the LED alarm light emits red and yellow light.

7. The method for detecting aviation kerosene concentration based on a composite sensor according to claim 5, characterized in that: The threshold of the first-level warning and the threshold of the second-level warning are set according to the lower explosion limit LEL of kerosene vapor, the threshold of the first-level warning is set to 25% LEL, and the threshold of the second-level warning is set to 50% LEL; the first-level warning adopts the LED alarm light and buzzer to jointly alarm, the LED alarm light flashes yellow, and the buzzer emits a medium tone; the second-level warning adopts the LED alarm light, buzzer, and vibrator to jointly alarm, the LED alarm light flashes red, the buzzer emits a high tone, the vibrator vibrates continuously, and the alarm is stopped by the button module.

8. The method for detecting aviation kerosene concentration based on a composite sensor according to claim 7, characterized in that: The setting of the lower explosion limit is based on the ratio of air volume to kerosene vapor volume determined by the partial pressure gas distribution method. Kerosene vapor is filled into the mixing chamber from low to high concentration, and an ignition experiment is performed. The average value Li of the maximum kerosene vapor concentration before explosion and the minimum kerosene vapor concentration when explosion occurs detected by the integrated detection unit and the composite judgment unit is taken. i represents the number of experiments, and the ignition experiment is repeated and each Li (L1, L2, L3...Ln) is recorded. After n experiments, the value of the lower explosion limit LEL is (L1+l2+...Ln) / n. The process of the ignition experiment is: First, a certain amount of aviation kerosene is added to the gas generating device, and then the aviation kerosene in the device is heated outside the launching device to generate some steam, and the kerosene steam in the gas generating device is respectively rushed into the mixing chamber and the shock tube by means of partial pressure distribution, and then a certain amount of air is introduced by opening the valve, and the circulation pump is turned on to circulate so that the gas in the mixing chamber and the shock tube is evenly mixed, and the igniter is connected to the shock tube for ignition and detonation, and the kerosene concentration data in the mixing chamber is collected at the same time; the kerosene concentration data in the mixing chamber is detected by using an integrated detection unit and a composite judgment unit.

9. An aviation kerosene concentration detection device based on a composite sensor for implementing the method described in any one of claims 1 to 8, characterized in that: include: Sensor detection unit, composite judgment unit and integrated early warning unit; The sensor detection unit includes: a semiconductor sensor module and an infrared sensor module; the semiconductor sensor module is formed by developing a micro-nano film on a MEMS micro-board, based on the entire silicon substrate, and is composed of a heater and a sensor surface sensitive material; the infrared sensor module is a gas sensor based on the NDIR infrared absorption principle, and is composed of a light source with a significant CH bond absorption effect, an optical cavity, a dual-channel detector, a narrow-band filter, and a microprocessor; The composite determination unit realizes dual-mode composite sensor signal acquisition and composite determination; the dual-mode composite sensor signal acquisition includes: semiconductor sensor module signal acquisition and infrared sensor module signal acquisition; The integrated early warning unit includes: a sensor signal acquisition and amplification module, a main control chip, an alarm module, an LCD module, and a power supply module; the main control chip adopts a microcontroller with an integrated A / D converter, a timer, a serial port module, and an LCD driver to realize data processing of the processing unit signal and functional control of other modules. The other modules include a signal acquisition and amplification module, a composite judgment unit, and an alarm module; the alarm module is composed of an LED alarm light, a buzzer, and a vibrator, and has triple alarms of sound, light, and vibration. The electric buzzer adopts a passive buzzer, and the vibrator adopts a button vibrator; the LCD module includes a key module and a backlight detection module. The key module realizes multiple functions in different working states. The working state is divided into an alarm state and a non-alarm state. The backlight detection module is responsible for detecting the ambient light intensity; the power module adopts a lithium battery to continuously supply power to each module.

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