Laser hydrogen detection equipment for replacement operation of hydrogen-doped natural gas pipeline

Abstract

The utility model relates to the technical field of hydrogen detection equipment, in particular to laser hydrogen detection equipment for replacement operation of a hydrogen-doped natural gas pipeline. According to the technical scheme, the device comprises a box body and further comprises a main control module, a laser control module, a laser light source, a wavelength locking module, a cavity enhancement gas chamber, a photoelectric detection module and a phase-locked amplification module which are fixedly installed in the box body, and the main control module is connected with the laser control module, the wavelength locking module and the phase-locked amplification module; and the photoelectric detection module is positioned in the cavity enhancement gas chamber and is connected with the phase-locked amplification module. According to the utility model, the cavity enhancement technology and the modulation laser absorption spectrum technology are adopted, so that the problems of poor selectivity, low precision, slow response speed, weak anti-interference capability and complex maintenance in the prior art are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogen detection equipment, in particular to laser hydrogen detection equipment used for hydrogen-doped natural gas pipeline replacement operations. Background Art

[0002] Pipeline hydrogen transportation is a key way to reduce hydrogen storage and transportation costs and promote its large-scale application. Driven by the "dual carbon" goals, now is an opportune time to conduct pipeline hydrogen transportation demonstrations. However, traditional sensors based on catalytic combustion, thermal conductivity, and semiconductors are susceptible to the effects of combustible gases like methane during detection, resulting in inaccurate readings. This is particularly critical during pipeline replacement operations, as incomplete replacement can pose serious safety risks.

[0003] Existing hydrogen detection technology has multiple technical defects. The working principle of traditional sensors is easily affected by environmental changes, resulting in inaccurate detection results. Traditional sensors have a slow response speed and cannot reflect changes in hydrogen concentration in real time, affecting operational efficiency. These sensors have a long response time and cannot reflect the dynamic changes in hydrogen concentration in a timely manner. Existing sensors are easily interfered with by other components in hydrogen-blended natural gas, resulting in deviations in detection results and affecting the safety of replacement operations. Other components in hydrogen-blended natural gas will interfere with the detection results of the sensor, resulting in inaccurate readings. Sensors are susceptible to contamination and aging, requiring frequent calibration and maintenance, which increases the cost and workload of use. The physical and chemical properties of traditional sensors are easily affected by the external environment, resulting in performance degradation and the need for regular maintenance. Utility Model Content

[0004] The purpose of the utility model is to address the problems existing in the background technology and to propose a portable laser hydrogen detection device based on tunable diode laser absorption spectroscopy (TDLAS) technology for hydrogen-doped natural gas pipeline replacement operations.

[0005] The technical solution of the utility model is: a laser hydrogen detection device for hydrogen-doped natural gas pipeline replacement operation, including a box body and also including:

[0006] A main control module, a laser control module, a laser light source, a wavelength locking module, a cavity enhancement chamber, a photoelectric detection module, and a phase-locked amplifier module are fixedly installed in the box. The main control module is connected to the laser control module, the wavelength locking module, and the phase-locked amplifier module respectively. The photoelectric detection module is located at the light outlet of the cavity enhancement chamber and is connected to the phase-locked amplifier module.

[0007] The laser light source emits infrared laser light, and injects the infrared laser light into the cavity enhancement air chamber after being collimated;

[0008] The cavity enhancement chamber increases the interaction length between the infrared laser and the gas in the cavity enhancement chamber.

[0009] Optionally, a temperature control and pressure control module is fixedly installed in the box, and the cavity enhancement air chamber is located inside the temperature control and pressure control module.

[0010] Optionally, a battery is fixedly installed in the box, and the battery provides power for the main control module, the laser control module, the phase-locked amplifier module and the temperature control and voltage control module.

[0011] Optionally, an air intake component is installed in the box body, and the air intake component transports gas to the interior of the cavity enhancement air chamber.

[0012] Optionally, the air intake component includes an air inlet and an exhaust port provided on the box body, and an air pump fixedly installed in the box body, the input end of the air pump is connected to the air inlet, the output end of the air pump is connected to the cavity enhancement air chamber, and the air pump is electrically connected to the battery.

[0013] Optionally, a drying dust removal pipe is fixedly installed in the box, one end of the drying dust removal pipe is fixedly connected to the input end of the air pump, and the other end of the drying dust removal pipe is connected to the air inlet.

[0014] Optionally, a concentration display module is fixedly mounted on the box body, and the concentration display module is connected to the main control module.

[0015] Optionally, a power switch for controlling the total power supply of the device and a laser switch for controlling the on / off state of the laser light source are fixedly mounted on the box.

[0016] Optionally, a flow meter and a flow meter knob are fixedly mounted on the box body, and the flow meter knob adjusts the size of the intake air flow by controlling the flow meter.

[0017] In summary, this application includes at least one of the following beneficial technical effects:

[0018] By adopting cavity enhancement technology and modulated laser absorption spectroscopy technology, the problems of poor selectivity, low precision, slow response speed, weak anti-interference ability and complex maintenance existing in the existing technology are solved.

[0019] By employing cavity enhancement technology and modulated laser absorption spectroscopy, and utilizing narrow-linewidth, highly selective lasers, this method achieves highly selective detection of hydrogen in hydrogen-doped natural gas pipelines through precise spectral absorption detection. The narrow linewidth and high selectivity of the laser reduce the impact of environmental factors on detection results, improving detection accuracy. By tuning the laser wavelength, it precisely scans the characteristic absorption peak of hydrogen, avoiding interference from other gases and environmental factors.

[0020] Fast tuning and real-time signal processing technologies enable real-time monitoring of hydrogen concentration, improving operational efficiency. High-speed tunable lasers and fast signal processing algorithms ensure that changes in hydrogen concentration are detected and reflected promptly. By modulating the laser drive signal and employing second harmonic detection, low-frequency interference is eliminated, the signal-to-noise ratio is improved, and the accuracy of test results is ensured.

[0021] The laser detection system has high stability, which reduces the frequency of calibration and maintenance, lowering the cost and workload. The long service life and high stability of the laser system reduce the contamination and aging of the sensor, reducing maintenance requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of the exterior of the box body of the utility model is given;

[0023] Figure 2 A schematic diagram of the structure inside the box of the utility model is given;

[0024] Figure 3 A logical relationship diagram of the present utility model is given.

[0025] Figure numerals: 1. Box; 2. Main control module; 3. Laser control module; 4. Laser light source; 5. Wavelength locking module; 6. Cavity enhancement chamber; 7. Photoelectric detection module; 8. Phase-locked amplifier module; 9. Temperature control and pressure control module; 10. Battery; 11. Concentration display module; 12. Air inlet; 13. Exhaust port; 14. Air pump; 15. Drying and dust removal pipe; 16. Power switch; 17. Laser switch; 18. Flow meter; 19. Flow meter knob. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below with reference to the accompanying drawings and specific embodiments.

[0027] Example

[0028] like Figure 1-3As shown, the laser hydrogen detection device for hydrogen-doped natural gas pipeline replacement operations proposed in the present invention comprises a housing 1, a main control module 2, a laser control module 3, a laser light source 4, a wavelength locking module 5, a cavity enhancement chamber 6, a photoelectric detection module 7, and a phase-locked amplifier module 8, all fixedly mounted within the housing 1. The main control module 2 is the core control unit of the system, responsible for overall system control and data processing. The laser control module 3 controls the operating state of the laser light source 4 according to instructions from the main control module 2. It adjusts the operating parameters of the laser light source 4, such as laser power and frequency, to ensure that the laser light output by the laser light source 4 meets detection requirements. The wavelength locking module 5 ensures that the laser light output by the laser light source 4 is within a specific wavelength range. Through a feedback control mechanism, it monitors and adjusts the wavelength of the laser light source 4 in real time to ensure a stable and accurate wavelength. The laser light source 4 is a key component of the device, responsible for emitting infrared laser light. The photoelectric detection module 7 converts the optical signal emitted from the cavity enhancement chamber 6 into an electrical signal, which is then fed into the phase-locked amplifier module 8. The phase-locked amplifier module 8 amplifies and processes the signal output by the photoelectric detection module 7. It transmits the amplified detection signal to the main control module 2, and the main control module 2 calculates the hydrogen concentration in the gas to be tested based on the amplified detection signal.

[0029] The main control module 2 is connected to the laser control module 3, the wavelength locking module 5, and the phase-locked amplifier module 8, respectively. The photoelectric detection module 7 is located inside the cavity enhancement chamber 6 and is connected to the phase-locked amplifier module 8. The main control module 2 outputs modulation and scanning signals to the laser control module 3. Based on the modulation and scanning signals, the laser control module 3 controls the laser light source 4 to emit infrared laser light, which is then collimated and injected into the cavity enhancement chamber 6. The cavity enhancement chamber 6 increases the interaction length between the infrared laser light and the gas within the cavity enhancement chamber 6, thereby improving the gas detection sensitivity. In the cavity enhancement chamber 6, the infrared laser light signal of a specific wavelength is absorbed by the gas to be measured. Based on the light absorption effect, the photoelectric detection module 7 detects the gas to be measured and outputs a detection signal to the phase-locked amplifier module 8. The phase-locked amplifier module 8 amplifies the detection signal and transmits it to the main control module 2. The main control module 2 calculates the hydrogen concentration in the gas to be measured based on the amplified detection signal. A concentration display module 11 is fixedly mounted on the housing 1 and is connected to the main control module 2. The calculated hydrogen concentration in the gas to be measured will be displayed on the concentration display module 11 .

[0030] A temperature- and pressure-controlled module 9 is fixedly installed within the housing 1, and the cavity-enhancing gas chamber 6 is located within the module. The absorption spectrum of gas molecules changes with temperature. Controlling the gas temperature through the module ensures the stability of the absorption spectrum, thereby improving detection accuracy. Controlling the pressure of the gas being measured through the module helps maintain a constant density of the gas sample, as the absorption coefficient of the gas is pressure-dependent.

[0031] A battery 10 is fixedly mounted within the housing 1, providing power to the main control module 2, laser control module 3, phase-locked amplifier module 8, and temperature and voltage control module 9. A power switch 16, which controls the overall power supply to the device, and a laser switch 17, which controls the on / off state of the laser light source 4, are also fixedly mounted on the housing 1.

[0032] like Figure 1-3 As shown, an air intake component is installed in the box body 1, and the air intake component transports the gas to the interior of the cavity enhancement chamber 6. The air intake component includes an air inlet 12 and an exhaust port 13 provided on the box body 1, and an air pump 14 fixedly installed in the box body 1. The input end of the air pump 14 is connected to the air inlet 12, the output end of the air pump 14 is connected to the cavity enhancement chamber 6, and the air pump 14 is electrically connected to the battery 10. A drying dust removal pipe 15 is fixedly installed in the box body 1, one end of the drying dust removal pipe 15 is fixedly connected to the input end of the air pump 14, and the other end of the drying dust removal pipe 15 is connected to the air inlet 12. The gas to be tested is introduced into the cavity enhancement chamber 6 through the air pump 14. The gas to be tested will pass through the drying dust removal pipe 15 before entering the air pump 14. The gas passing through the drying dust removal pipe 15 will be dust-removed and dehumidified, and the tested gas will be discharged to the outside of the box body 1 through the air outlet.

[0033] A flow meter 18 and a flow meter knob 19 are fixedly mounted on the box body 1 , and the flow meter knob 19 adjusts the size of the intake air flow by controlling the flow meter 18 .

[0034] Working principle: In actual application, the device is first placed at a key node of the natural gas pipeline, and the instrument is started. First, the gas in the pipeline is introduced into the box 1 through the air pump 14, and the gas is input into the cavity enhancement chamber 6. Then the main control module 2 outputs the modulation and scanning signal to the laser control module 3, controls the laser light source 4 to emit infrared laser, and collimates it and injects it into the cavity enhancement chamber 6. In the cavity enhancement chamber 6, the infrared laser interacts with the gas to be measured, and the laser of a specific wavelength is absorbed by the gas to be measured. The photoelectric detection module 7 converts the light signal with the gas absorption signal into an electrical signal and sends it to the phase-locked amplifier module 8. The phase-locked amplifier module 8 extracts the second harmonic signal, amplifies the second harmonic signal, and transmits it to the main control module 2. The main control module 2 calculates the hydrogen concentration in the gas to be measured based on the amplified detection signal, and finally displays the detection result through the liquid crystal display module for the operator's reference.

[0035] The above specific embodiments are merely several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant inspirations of the above embodiments, those skilled in the art may make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A laser hydrogen detection device for hydrogen-doped natural gas pipeline replacement operation, comprising a housing (1), characterized in that: Also includes: A main control module (2), a laser control module (3), a laser light source (4), a wavelength locking module (5), a cavity enhancement chamber (6), a photoelectric detection module (7) and a phase-locked amplifier module (8) are fixedly installed in the box (1); the main control module (2) is connected to the laser control module (3), the wavelength locking module (5) and the phase-locked amplifier module (8) respectively; the photoelectric detection module (7) is located at the light outlet of the cavity enhancement chamber (6); and the photoelectric detection module (7) is connected to the phase-locked amplifier module (8); The laser light source (4) emits infrared laser light, and after collimation, injects the infrared laser light into the cavity enhancement chamber (6); The cavity enhancement chamber (6) increases the interaction length between the infrared laser and the gas in the cavity enhancement chamber (6).

2. The laser hydrogen detection equipment for hydrogen-blended natural gas pipeline replacement operation according to claim 1 is characterized in that: A temperature control and pressure control module (9) is fixedly installed in the box (1), and the cavity enhancement air chamber (6) is located inside the temperature control and pressure control module (9).

3. The laser hydrogen detection equipment for hydrogen-blended natural gas pipeline replacement operation according to claim 2 is characterized in that: A battery (10) is fixedly installed in the box (1), and the battery (10) provides power for the main control module (2), the laser control module (3), the phase-locked amplifier module (8), and the temperature control and voltage control module (9).

4. The laser hydrogen detection equipment for hydrogen-blended natural gas pipeline replacement operation according to claim 3 is characterized in that: An air intake component is installed in the box body (1), and the air intake component transports gas to the interior of the cavity enhancement air chamber (6).

5. The laser hydrogen detection equipment for hydrogen-blended natural gas pipeline replacement operation according to claim 4 is characterized in that: The air intake component comprises an air intake port (12) and an air exhaust port (13) provided on the box body (1), and an air pump (14) fixedly installed in the box body (1); an input end of the air pump (14) is connected to the air intake port (12); an output end of the air pump (14) is connected to the cavity enhancement air chamber (6); and the air pump (14) is electrically connected to the battery (10).

6. The laser hydrogen detection equipment for hydrogen-blended natural gas pipeline replacement operation according to claim 5 is characterized in that: A drying dust removal pipe (15) is fixedly installed in the box body (1), one end of the drying dust removal pipe (15) is fixedly connected to the input end of the air pump (14), and the other end of the drying dust removal pipe (15) is connected to the air inlet (12).

7. The laser hydrogen detection equipment for hydrogen-blended natural gas pipeline replacement operation according to claim 6 is characterized in that: A concentration display module (11) is fixedly mounted on the box body (1), and the concentration display module (11) is connected to the main control module (2).

8. The laser hydrogen detection equipment for hydrogen-blended natural gas pipeline replacement operation according to claim 7 is characterized in that: A power switch (16) for controlling the total power supply of the device and a laser switch (17) for controlling the on / off state of the laser light source (4) are fixedly mounted on the box (1).

9. The laser hydrogen detection equipment for hydrogen-blended natural gas pipeline replacement operation according to claim 8, characterized in that: A flow meter (18) and a flow meter knob (19) are fixedly mounted on the box body (1), and the flow meter knob (19) adjusts the size of the intake air flow by controlling the flow meter (18).

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