CN109736993B - 2-micron-waveband laser ignition device and ignition method - Google Patents
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Abstract
A2 mu m wave band laser ignition device and an ignition method belong to the technical field of laser. The ignition method is divided into two stages, wherein in the first stage, the YAG laser with a wave band is built by self-help to preheat the fuel; the second stage is again fired with a stable high energy 1064nm laser. The preheating device includes heating part and detection part, and wherein the detection part includes: an imaging system is built by using a high-brightness LED lamp, a convex lens, a concave lens, a diaphragm and a plane mirror, so that the imaging system passes through an experimental fuel cell, a high-speed CMOS is used, the heat distribution condition of water vapor in a preheating stage is recorded by a schlieren method, and the temperature of fuel is monitored by using an infrared thermometer. A heating part firstly uses a Ho-YAG laser to focus two beams of laser at an output end through a concave lens and a convex lens, preheats the fuel at a beam waist, and ignites through high-power Nd-YAG of 1064nm after the temperature reaches a monitoring temperature, so that the ignition success rate is greatly improved, the minimum ignition energy is reduced, and the ignition of the engine in a lean burn state is realized.
Description
Technical Field
The invention belongs to the technical field of laser, and particularly relates to a 2-micron-band laser ignition device and an ignition method.
Background
Combustion is an important source of energy and power required for human production and life. With the acceleration of industrialization, the available reserves of non-renewable energy sources such as coal, oil, natural gas and the like are reduced rapidly, and the byproducts such as greenhouse gases, nitrogen oxides, particulate matters and the like generated along with combustion cause serious environmental problems such as greenhouse effect, ozone holes, acid rain and the like, thereby causing serious influences on the global environment and human life. Therefore, how to improve the combustion efficiency of the combustion system and reduce the emission of pollutants becomes an important issue in the combustion science community today.
Research shows that the temperature is low during the lean combustion reaction, the emission of nitrogen oxides can be effectively reduced, the fuel can be greatly saved, the combustion efficiency is improved, and the method is an effective way for solving the energy and environmental problems of the current combustion system. However, during the lean combustion reaction, due to the relative shortage of fuel, the probability of flameout and failure of ignition of the combustion system is increased, which has a serious influence on the stability of the combustion system. How to ensure the ignition reliability of the lean burn system provides a severe test for the spark plug ignition system adopted by the current natural gas engine and internal combustion engine. In order to increase the success rate of ignition, the discharge voltage between the spark plug electrodes needs to be greatly increased. The high voltage operation in turn accelerates the erosion of the electrodes, leading to an increase in the electrode spacing, which in turn requires a further increase in the discharge voltage. This vicious circle greatly shortens the service life of the spark plug. Therefore, research on a novel ignition mode to realize stable and reliable ignition of a lean-burn system becomes a research hotspot in the field of advanced engines at present.
The laser-induced plasma ignition (LIPI) is developed on the background that the traditional ignition mode faces the technical development bottleneck. Pulse laser is focused into mixed fuel gas, plasma is generated through the processes of multiphoton ionization, avalanche ionization, reverse bremsstrahlung and the like, combustion active groups are generated through the induction of the thermal effect and the combustion chemical reaction effect caused by the plasma, an initial fire nucleus is formed, and then the ignition of the mixed fuel gas is realized through the propagation of the initial fire nucleus. The technical advantages of the LIPI make it hopeful to break through the ignition technical bottleneck faced by combustion systems such as lean-burn combustion systems and rocket engines, and promote the development of related fields, thus gaining wide attention of researchers. LIPI experiments are carried out on four propellants including GOX/GH, GOX/GCH, GOX/RP-1 and GOX/GCO by YAG laser with the wavelength of 1064nm by the lious research Center of the national aerospace administration, namely NASA Lewis research Center, so that the influences of experiment conditions such as propellant equivalence ratio, combustion chamber pressure, laser pulse energy, repetition frequency and the like on LIPI are obtained, and the electromagnetic interference of LIPI is lower by one order of magnitude than that of an electric spark plug ignition system. A Marshall Space Flight Center Marshall Flight height Center in the United states of America and Ross alamos national Laboratory collaborates, carries out research work of a double-pulse combination LIPI technology, and two Nd: YAG lasers with the wavelength of 1064nm are adopted to carry out LIPI experiments on a plurality of rocket propellants such as GOX/GH2, GOX/CH4, GOX/RP-1 and the like. Research shows that the total energy requirement of laser ignition can be effectively reduced by using double-pulse combination. The National Aerospace Laboratory of Japan used laser ablation of stainless steel and other materials, and two-stream impinging jet type GOX/GH2 and GOX/GCH4 propellants were subjected to LIPI research in a model rocket engine. The Oschwald project group of German aviation space agency German Aerospace Center, DLR adopts high-speed photography technology to carry out LIPI (local injection pressure) experiments on LOX/GH2 and GOX/GCH4 propellants on a simulated combustor of a small rocket engine, so that the transient processes of propellant injection and flame are obtained, the LIPI experiments under the vacuum condition are carried out, and the working condition of high-altitude ignition of the engine is simulated.
In summary, validated experimental work has been conducted on engineering applications of LIPI in a number of engine areas. It should be noted, however, that the LIPI requirement for ignition laser pulse energy remains a significant factor limiting its engineering applications. In these confirmatory experiments, the laser pulse energy required for LIPI to achieve successful ignition was typically tens of mJ, and some even more than 100 mJ. This will undoubtedly cause heavy burden on the size, power consumption, etc. of the ignition laser system, limiting the engineering application of LIPI. Despite recent advances in miniaturized laser igniters, there is still a need for further research into the working volume of LIPI to reduce the need for ignition laser systems, such as laser ablation plasma ignition and dual pulse combination ignition.
Disclosure of Invention
The invention aims to realize high-efficiency ignition, enable combustion to be more sufficient, realize ignition in a lean combustion range, reduce the emission of pollutants and simultaneously reduce the energy requirement of an ignition light source, and promote the development of engineering application.
The purpose of the invention is realized as follows:
a 2 μm band laser ignition device comprising: the laser preheating device is divided into a laser preheating device detection part and a laser preheating device heating part; the device specifically comprises a light source 1, a lens 2, a convex lens 3, a diaphragm 4, a plane mirror 5, a knife edge 6, a gas unit 7, a high-speed CMOS8 and a 2-micrometer HO: YAG laser 9, converged laser beam 10, fuel nozzle 11, infrared ray instrument 12, spectrometer and power meter 13, control valve 14, gas pipe 15, flowmeter 16, vacuum pump 17, water gas 18, methane 19 and fuel 20; the laser preheating device heating part comprises a 2 μm HO: YAG laser 9 and focused laser beam 10; 2 μmHO: YAG9 generates high energy pulses in the 2 μm band and sends them into the gas cell 7 by converging the laser beam 10; the detection part of the laser preheating device comprises a schlieren device, an infrared hot-wire instrument 12 and a spectrometer and power meter 13; the schlieren device is an imaging system which is formed by a light source 1 passing through a lens 2, a convex lens 3, a diaphragm 4, a plane mirror 5, a knife edge 6, a gas unit 7 and a high-speed CMOS8 in sequence; light generated by a light source 1 of the schlieren device sequentially passes through a lens 2, a convex lens 3 and a diaphragm 4 and then enters a gas unit 7 through a plane mirror 5, emergent light passing through the gas unit 7 is reflected to a knife edge 6 through the plane mirror, and then is parallelly emitted into a high-speed CMOS8 through a convex lens; an infrared hotwire 12 and a spectrometer and power meter 13 are positioned around the gas cell 7; the laser ignition device is a 1064nm Nd: YAG laser system and is positioned around the mixed fuel gas chamber opening, and the fuel nozzle 11 is positioned around the gas unit 7.
The mixed fuel gas chamber comprises a control valve 14, a gas conveying pipe 15, a flow meter 16, a vacuum pump 17, water gas 18, methane 19 and fuel 20, wherein one end of the gas conveying pipe 15 is communicated with the vacuum pump 17, the water gas 18, the methane 19 and the fuel 20 respectively after passing through the flow meter 16; the other end of the gas pipe 15 is connected to the gas unit 7 through a control valve 14.
The ratio of 2 mu mHO: the YAG laser 9 is a Q-switched crystal of a solid two-dimensional material of autonomous design, having a high pulse energy.
The mixed fuel gas chamber is controlled by a control valve 14, and is pre-mixed after being vacuumized.
The infrared hotline 12 records the temperature condition of the combustion boundary in a multipoint temperature collection mode.
The light source of the schlieren device is a high-brightness LED lamp, and an image formed on the light path reaches the knife edge through the lens and then is imaged through the high-speed CMOS.
A2-micron-band laser ignition method comprises the steps of firstly completing premixing, preheating by using a 2-micron laser, detecting by using a detection system, and igniting by using a 1064nm laser with higher power after the ignition temperature is reached.
The invention has the beneficial effects that:
the problem of laser ignition failure existing at present is solved through the precombustion device, has improved the ignition success rate. Meanwhile, the high requirement on the ignition laser energy is reduced, unnecessary energy waste is reduced, and the ignition safety is improved.
Drawings
FIG. 1 is a diagram of a preheating system;
FIG. 2 is a diagram of a mixing chamber.
Detailed Description
The invention is described in more detail below with reference to the accompanying drawings.
A2 μm wave band laser ignition device and an ignition method comprise: the laser preheating device comprises a detection part and a heating part.
The preheating and ignition part focuses the laser by using a set light path so that the laser reaches the test chamber.
The detection part comprises a schlieren device and an infrared temperature measuring device.
The detection part in the preheating device can record the temperature condition generated by water absorption by using a schlieren method, and comprises high-brightness LED lamps, convex lenses, concave lenses, diaphragms and high-speed CMOS.
The detection part and the infrared temperature measurement part in the preheating device use a non-contact infrared thermometer to monitor the temperature of the preheating system.
YAG laser is used in the heating part of the preheating device, high energy pulse of 2 micron wave band is generated, and water vapor in the fuel with strong absorption generates high temperature to preheat the fuel.
YAG laser uses high energy Nd after preheating, two beams of laser are focused at the output end through concave lens and convex lens, and the fuel is ignited at the beam waist.
The holmium-doped HO: YAG laser can generate laser with a wave band of 2 mu m, and the laser is focused by double pulses through an optical system in advance and then enters a fuel gas chamber. To monitor fuel combustion, we used schlieren to make optical measurements of the interior of the flame. The high-brightness LED lamp is used as a light source, passes through the convex lens and the diaphragm, is reflected by the planar mirror to pass through the fuel gas chamber, and the light beam after coming out enters the high-speed CMOS through the lens group, and the CMOS can record the heat distribution state of a combustion interface. The external device is provided with an infrared temperature detector which can carry out multi-point detection on the preheating system and carry out ignition after reaching the preheating temperature. The ignition device is a 1064nm Nd-YAG laser system, and the combustion condition can still be measured by the monitoring system through the ignition device which is focused on the mixed fuel gas chamber for a certain distance.
The invention also includes such features:
1. the 2um laser used in the experiment uses a self-designed solid two-dimensional material as a Q-switched crystal and has very high pulse energy.
2. The premixing device of the fuel gas chamber is controlled by a gas valve, and is premixed after being vacuumized.
3. The fuel cell is premixed and includes a volume fraction of a mixed fuel of water and air and methane.
4. The temperature of the preheating system adopts a multipoint temperature collection mode, and the temperature conditions of a plurality of combustion boundaries can be obtained. Thereby obtaining the temperature distribution.
5. The light of the schlieren device is a high-brightness LED lamp, and the image formed on the light path reaches the knife edge through the lens and then is imaged through the high-speed CMOS.
The 6.1064nm laser has very high pulse energy, and the schlieren device can record the condition of the ignition moment and judge the ignition success.
7. The output power of the laser is measured in advance by a power meter, an oscilloscope and a spectrometer, and the laser ignition mechanism is analyzed and researched greatly.
As shown in fig. 1, the preheating system is composed of a preheating section and a detection section, and the preheating section uses 2 μmHO: YAG laser, after lens focus, preheat the premix fuel in focus, the light after the emergence measures its power through the power meter, calculate the residual power of the laser after preheating and provide the data for studying the ignition mechanism, can detect and get the absorption spectrum of laser spectrum and material through connecting the spectrometer, provide the data to studying the factor that the equivalent ratio is successful to igniting. The detection part uses a set of schlieren system, the high-brightness LED light source is focused by a lens, then the high-brightness LED light source penetrates through a fuel gas chamber by a plane mirror, the combustion process of the fuel in the ignition process is recorded, the emitted light is focused on a knife edge by the lens, and the image information of each frame in the combustion reaction process can be obtained after the high-speed CMOS is used for exposure.
As shown in figure 2, the gas pipe of the gas chamber is controlled by a plurality of gas valves, the gas is firstly pumped by a vacuum pump to ensure that the premixing gas chamber is in a vacuum state, then the gas proportion is calculated according to theory, and the proportion of methane and air is controlled by a flowmeter. The research of laser ignition under different equivalence ratios can be realized in a controllable manner, data are provided for the research of LIPI influence ignition mechanism factors, a certain percentage of water is added according to the spectral line absorption characteristic of the water, and the whole premixing process is finished.
In use, the invention firstly completes premixing, preheats with a 2 μm laser, a detection system detects, after reaching the ignitable temperature, the system ignites with a 1064nm laser with relatively high power, and the whole system has great value for researching the relationship between the equivalent ratio and the active group concentration in the laser power, the minimum ignition energy and the ignition success, and the LIPI mechanism and the engineering application thereof.
Claims (6)
1. A 2 μm band laser ignition device, comprising: the laser preheating device is divided into a laser preheating device detection part and a laser preheating device heating part; the optical lens specifically comprises a light source (1), a lens (2), a convex lens (3), a diaphragm (4), a plane mirror (5), a knife edge (6), a gas unit (7), a high-speed CMOS (8) and a 2 mu m HO: YAG laser (9), converged laser beam (10), fuel nozzle (11), infrared thermal instrument (12), spectrometer and power meter (13), control valve (14), gas pipe (15), flowmeter (16), vacuum pump (17), water vapor (18), methane (19) and fuel (20); the laser preheating device heating part comprises a 2 μm HO: a YAG laser (9) and a converging laser beam (10); 2 μm HO: YAG laser (9) generates high energy pulse with 2 μm wave band and sends the pulse into gas unit (7) through converging laser beam (10); the detection part of the laser preheating device comprises a schlieren device, an infrared hot-wire instrument (12), a spectrograph and a power meter (13); the schlieren device is an imaging system which is formed by a light source (1) sequentially passing through a lens (2), a convex lens (3), a diaphragm (4), a plane mirror (5), a knife edge (6), a gas unit (7) and a high-speed CMOS (8); light generated by a light source (1) of the schlieren device sequentially passes through a lens (2), a convex lens (3) and a diaphragm (4) and then enters a gas unit (7) through a plane mirror (5), emergent light passing through the gas unit (7) is reflected to a knife edge (6) through the plane mirror, and then is parallelly emitted into a high-speed CMOS (8) through the convex lens; the infrared hotline instrument (12) and the spectrograph and the power meter (13) are positioned around the gas unit (7); the laser ignition device is a 1064nm Nd: YAG laser system and is positioned around the mixed fuel gas chamber opening, and the fuel nozzle (11) is positioned around the gas unit (7).
2. The 2 μm-band laser ignition device according to claim 1, characterized in that: the mixed fuel gas chamber comprises a control valve (14), a gas conveying pipe (15), a flowmeter (16), a vacuum pump (17), water vapor (18), methane (19) and fuel (20), wherein one end of the gas conveying pipe (15) is communicated with the vacuum pump (17), the water vapor (18), the methane (19) and the fuel (20) respectively after passing through the flowmeter (16); the other end of the gas pipe (15) is connected to the gas unit (7) through a control valve (14).
3. A 2 μm-band laser ignition device according to claim 2, characterized in that: the mixed fuel gas chamber is controlled by a control valve (14), and pre-mixing is carried out after vacuum pumping.
4. The 2 μm-band laser ignition device according to claim 1, characterized in that: the infrared ray instrument (12) records the temperature condition of the combustion boundary in a multi-point temperature collection mode.
5. The 2 μm-band laser ignition device according to claim 1, characterized in that: the light source of the schlieren device is a high-brightness LED lamp, and an image formed on the light path reaches the knife edge through the lens and then is imaged through the high-speed CMOS.
6. The 2 μm-band laser ignition method of a 2 μm-band laser ignition device according to claim 1, characterized in that:
firstly, a heating part of a laser preheating device preheats, a detection part of the laser preheating device detects, and after the ignition temperature is reached, a 1064nm Nd-YAG laser system with higher power is used for ignition.
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| CN110514780A (en) * | 2019-08-27 | 2019-11-29 | 东北大学 | A kind of laser ignition measurement gas minimum ignition energy system and application method |
| CN113280998A (en) * | 2021-05-21 | 2021-08-20 | 中国人民解放军战略支援部队航天工程大学 | Shock wave imaging system and method for laser ablation of target material |
| CN113431723B (en) * | 2021-07-14 | 2022-09-16 | 吉林大学 | Optical fiber ablation ignition system and method based on femtosecond laser ignition |
| CN114837856B (en) * | 2022-05-22 | 2023-11-24 | 浙江大学 | Method for measuring ignition energy of solid energetic fuel |
| CN117269008B (en) * | 2023-09-22 | 2024-05-03 | 哈尔滨工业大学 | High-concentration soot volume fraction measuring device and method based on laser preheating |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105134452A (en) * | 2015-08-24 | 2015-12-09 | 中国科学院半导体研究所 | Device and method for ignition through dual-mode lasers in target portion breakdown manner |
| CN107431328A (en) * | 2015-01-20 | 2017-12-01 | 金南成 | Efficient laser-ignition unit |
| CN108443044A (en) * | 2018-05-10 | 2018-08-24 | 浙江大学 | A kind of engine laser-ignition unit and its method |
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| EP3376021B1 (en) * | 2017-03-16 | 2022-05-04 | Ricoh Company, Ltd. | Laser device and internal combustion engine |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107431328A (en) * | 2015-01-20 | 2017-12-01 | 金南成 | Efficient laser-ignition unit |
| CN105134452A (en) * | 2015-08-24 | 2015-12-09 | 中国科学院半导体研究所 | Device and method for ignition through dual-mode lasers in target portion breakdown manner |
| CN108443044A (en) * | 2018-05-10 | 2018-08-24 | 浙江大学 | A kind of engine laser-ignition unit and its method |
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