CN203465172U - Micro-combustion, gasified suspension, imaging and detection system for single particle fuel - Google Patents

Abstract

The utility model relates to a micro-combustion, gasified suspension, imaging and detection system for single particle fuel. Fuel which is used in a micro-energy source system based on micro-combustion is gas fuel in general at present, but the gas fuel is not easy to store and carry. The micro-combustion, gasified suspension, imaging and detection system comprises a first laser driver, a first laser device, a second laser driver, a second laser device, a first reflector, a first beam splitter, an inverted telescope, a second beam splitter, a high-power objective lens, microparticle fuel, a micro-combustion chip, a three-dimensional electric displacement platform, a collecting lens, a third beam splitter, an iris diaphragm, an illuminator, a light source, a first lens, a light filter, a four-quadrant detector, a second lens, a third beam splitter, a charge-coupled device (CCD) camera, a second reflector and an infrared video camera. The micro-combustion and gasification of particles are subjected to a non-interference test by adopting full optical particle suspending location, ignition and test methods, the micro-combustion and gasification truth can be well reflected, the essence is restored, and a mechanism is effectively revealed.

Description

A kind of single particulate fuel micro-combustion, gasification suspension, imaging and detection system

Technical field

The utility model belongs to micro-combustion technical field, relates to a kind of single particulate fuel micro-combustion, gasification suspension, imaging and detection system.

Background technology

Development along with micro-electromechanical system (MEMS) technology, because meeting the long-time power supply of portable electronic device and the demand of microminiature aerospace equipment high-performance power source and power supply, the research of micro-energy resource system has caused widely to be paid attention to, as micro-/receive satellite, micro-aircraft ,“ warrier of ground force " Single-soldier system, machine ant, mobile electronic equipment micro-energy resource system etc.Tradition micro-energy resource system is powered based on micro-lithium battery group mostly, but there is many deficiencies in lithium battery group power supply: energy density is lower, power-on time is shorter, while reusing the duration of charging long etc., be therefore difficult to meet that novel micro-energy resource system volume is little, lightweight, energy density is high, the requirement of uninterrupted long-time power supply etc.

1996, by Epstein and the Senturia of MIT, novel micro-energy resource system " Power MEMS " is proposed first, can produce electric energy 20W and thrust 0.125N.Then " Power MEMS " expands to micro fuel cell, minisize nuclear battery, miniature heat engine system etc.

Micro fuel cell has the advantage of low (80～100 ℃) efficiency of operating temperature higher (20～30%), but system is extremely complicated, especially fuel converter etc.Minisize nuclear battery has power-on time long (decaying 50 years), is disturbed little advantage, but has energy supply low (counting mW), the problems such as radioactive source is dangerous, difficulty is controlled in decay, microminiaturized difficulty.Miniature heat engine is to be burnt fuel chemical energy is converted to heat energy by microscale, then is converted to a kind of micro-energy resource system of electric energy or thrust, comprises low-grade fever electric system, low-grade fever photovoltaic system, micro-combustion turbine/start (electricity) machine system.These three kinds of miniature heat engine systems have relative merits separately, but each system needs fuel to carry out micro-combustion.

At present, the fuel that the micro-energy resource system based on micro-combustion is used is commonly gaseous fuel, because the combustion heat value of gaseous fuel is high, is easy to light, and supposes that energy conversion efficiency is 20%, more than gas fuel combustion energy density also can reach 2000W-hr/Kg.But gaseous fuel is difficult for storage, carries, and is a larger problem for miniature aerospace equipment and portable set.Can therefore there is a query: micro-combustion fuel be used liquid or solid microparticle fuel?

If use liquid or solid microparticle fuel, how micro-combustion is effectively controlled? integrated micro-combustion system how?

The utility model adopts full optical profile type particle to suspend and locates, lights imaging, and microparticle fuel micro-combustion is carried out to non-interference test, and can reflect micro-combustion and gasification authenticity, reduce its essence, effectively disclose its mechanism, can be used as standard burning and gasification method of testing.

Summary of the invention

The utility model is used micro-combustion in liquid or solid microparticle fuel micro-combustion system effectively to control and system integration problem in order to solve, and has proposed that a kind of single particulate fuel micro-combustion, gasification suspend, light, imaging and detection system.

The technical scheme that the utility model is taked is:

Single particulate fuel micro-combustion, gasification suspend, light, imaging and detection system, comprise the first laser driver, the first laser instrument, the second laser driver, second laser, the first reflective mirror, the first spectroscope, inverted telescope, the second spectroscope, high power objective, microparticle fuel, micro-combustion chip, three-D electric displacement platform, condenser, the 3rd spectroscope, iris, collecting lens, light source, first lens, optical filter, 4 quadrant detector, the second lens, the 3rd spectroscope, CCD camera, the second reflective mirror and thermal camera.

The light that the first laser instrument sends forms focal beam spot by the first spectroscope, inverted telescope, the second spectroscope and high power objective and carrys out microactuator suspension granular fuel; By regulating output power that the drive current of the first laser driver improves the first laser instrument to microparticle ignited fuel; The infrared radiating light that particle burning sends arrives by high power objective, the second spectroscope, the second lens, the 3rd spectroscope, the second reflective mirror that thermal camera carries out imaging and particulate Temperature Distribution detects; Described microparticle fuel is positioned in micro-combustion chip.

The light that second laser sends arrives 4 quadrant detector by the first reflective mirror, the first spectroscope, inverted telescope, the second spectroscope, high power objective, microparticle fuel, micro-combustion chip, condenser, the 3rd spectroscope, first lens, optical filter, obtain the position of microparticle fuel, second laser is driven by the second laser driver and controls.

The light that light source sends carries out Uniform Illumination by collecting lens, iris, the 3rd spectroscope, condenser to micro-combustion chip; Illumination light is carried out imaging, particulate form and particle diameter and is detected by high power objective, the second spectroscope, the second lens, the 3rd spectroscope arrival CCD camera.

The utility model adopts full optical profile type particle to suspend and locates, lights and method of testing, particle micro-combustion and gasification are carried out to non-interference test, can reflect micro-combustion and gasification authenticity, reduce its essence, effectively disclose its mechanism, can be used as standard burning and gasification method of testing, overcome a difficult problem for existing micro-combustion and the research of gasification mechanism.This technology can not only be applied to energy field, and can be used for the numerous areas such as environmental chemistry, life science, biological medicine and Aero-Space.

Accompanying drawing explanation

Fig. 1 is system architecture schematic diagram of the present utility model;

Fig. 2 is that single particulate fuel of the present utility model suspends and lights schematic diagram;

Fig. 3 is the position measurement schematic diagram of microparticle fuel of the present utility model;

Fig. 4 is microparticle fuel of the present utility model and micro-combustion chip illumination schematic diagram;

Fig. 5 is microparticle fuel shape of the present utility model, particle diameter and Temperature Distribution test schematic diagram.

Embodiment

Below in conjunction with accompanying drawing, the utility model is described in further detail.

As shown in Figure 1: the present embodiment mainly comprises the first laser driver 1, the first laser instrument 2, the second laser driver 3, second laser 4, the first reflective mirror 5, the first spectroscope 6, inverted telescope 7, 8, the second spectroscope 9, high power objective 10, microparticle fuel 11, micro-combustion chip 12, three-D electric displacement platform 13, condenser 14, the 3rd spectroscope 15, iris 16, collecting lens 17, light source 18, first lens 19, optical filter 20, 4 quadrant detector 21, the second lens 22, the 3rd spectroscope 23, CCD camera 24, the second reflective mirror 25 and thermal camera 26.

The light that the first laser instrument 2 sends forms focal beam spot by the first spectroscope 6, inverted telescope 7,8, the second spectroscope 9 and high power objective 10 and carrys out microactuator suspension granular fuel 11, microparticle fuel 11 is positioned in the micro-combustion chip 12 of design processing, micro-combustion chip 12 is controlled by three-D electric displacement platform 13, accurately changes the relative position of microparticle fuel 11 and light beam.Microparticle fuel 11 can be liquid (oil, alcohols), solid (coal, metal), biological particles (straw, stalk) and fuel blend etc.Microparticle fuel suspends and lights schematic diagram and see Figure of description 2.Stressed comprise laser emission power, photophoresis power, thermophoretic forces, drag force, thermal transpiration power, Blang power, gravity and the buoyancy etc. of microparticle fuel 11 in suspension, burning and gasification, it is analyzed as follows.

Laser emission power: under laser action, photon collision particle and direction occurs change, thus cause momentum change, according to the law of conservation of momentum and Newton second law, particle is subject to the acting force that photon collision produces.The expression formula of laser emission power is: wherein ε is that particle emissivity, c are the light velocity, P ₀for incident light gross energy, A _pfor particle cross-sectional area, A _beamfor beam cross-section amasss.Generally laser emission power is decomposed into scattering force (axial force) and gradient force (radial force).The laser emission power order of magnitude is generally 10 ^-12～10 ^-9n, is mainly limited to beam energy, pattern and waist radius.

Photophoresis power: during due to laser levitation particle, particle is subject to inhomogeneous electromagnetic action and causes the plane of incidence and shady face to occur small thermal deviation, gas molecule is larger than the momentum after cold side bounce-back after particle hot side bounce-back, thereby poor in hot side and cold side generation acting force.For this model, photophoresis power expression formula is: wherein R is that ideal gas constant, P are that gaseous tension, M are gas molecule quality, Q _absfor laser absorption coefficient, μ _gfor gas viscosity, k _gfor heat conductivity of gas, T _gfor gas temperature, T _pfor particle temperature, k _pfor particle thermal conductivity, J are the symmetrical factor (symmetry of Temperature Distribution after the thermal absorption of description particle), K _sLfor hot slip coefficient (0.75-1.169, the value while corresponding respectively to molecule to particle surface mirror reflection and during total scattered reflection).When grain diameter is 65-150um scope, its photophoresis power is larger.At grain diameter hour,

time, photophoresis power can be ignored, wherein h _pfor heat transfer coefficient.

Thermophoretic forces: because environmental gas exists thermograde, cause particle two surfaces to have small temperature difference along gas gradient direction, thus poor in hot side and cold side production function power.Be mainly the different of effect source from the difference of photophoresis power, photophoresis power is that inhomogeneous electromagnet source causes, and thermophoretic forces is gas temperature gradient source, causes.For this model, the expression formula of thermophoretic forces is:

$F_{\mathrm{th}}=\frac{-9{\mathrm{\&pi;\&mu;}}_g^2{d}_p{H\&dtri;\mathrm{<figure-callout\; id="2"\; label="T\; g"\; filenames="HDA0000370451030000021.png"\; state="\{\{state\}\}">T</figure-callout>}}_g}{2{\mathrm{\&rho;}}_g{T}_g}$

wherein, d _pfor particle diameter, ρ _gfor gas density, Kn are the Knudsen number ratio of mean molecule free path (particle diameter with).

Drag force: when particle is subject to laser action and be heated, gas can produce a drag force contrary with gravity direction in particle natural convection around, has nothing to do with beam direction.The drag force that natural convection produces is very large in particle effect in suspension, must accurately consider.For this model, the expression formula of drag force is:

F _d=3 π d _peffμ _gv _g, d wherein _pefffor particle effective diameter (larger than actual particle size, because need to consider convective boundary layer), V _gfor gas velocity.During for 900K, the suffered drag force of the particle of 40um is about 4.82e ^-10n.

Thermal transpiration power: be the main power in Crook radiometer, show as under vacuum condition when particle exists thermograde the small poor power existing between hot side and cold side.Most theories calculates and experimental result shows, the nano-scale particle in certain pressure environment can be subject to certain thermal transpiration power, and to micron particles, thermal transpiration power can be ignored.

Blang's power: particle under the collision of gas molecule, produces the indefinite net effort of a kind of fluctuation around, causes the Brownian movement of particulate.If the chance that Brownian Particles collides is mutually seldom, can regard the ideal gas that giant molecule forms as, in gravity field, reach after thermal equilibrium, its number density should be followed Boltzmann by the distribution of height and distribute.Utilize Boltzmann factor R _thermaljudge the influence that Blang's power suspends to particle.If R _thermal=exp (U _max/ k _bt _g) < < 1, Blang's power can be ignored so, wherein k _bfor Boltzmann constant, U _maxfor light beam potential well maximal value.Getting particulate refractive index is 1.5, light beam focal plane and near, R _thermalbe 10 ^-65magnitude, so Blang's power can be ignored.

Gravity and buoyancy expression formula are respectively:

ρ wherein _pfor particle density.Suppose that the density of particle is 1～2 * 10 ³kg/m ^-3between, particle diameter is several microns, the order of magnitude of gravity is 10 ^-14～10 ^-13between N, compare with gradient force, the gravitational effect impact of particle is minimum.Because gas density is minimum, so buoyancy can be ignored.

Therefore for the stress model of micron particles fuel, mainly consider laser emission power, photophoresis power, thermophoretic forces and drag force etc.In micro-combustion and gasification, because separate out fugitive constituent gas, so physical property of particle parameter and environment physical parameter (being mainly particle diameter, density, emissivity) change, particle can be affected stressed.The variation of environmental gas density and refractive index is very little, so exert an influence very little to laser emission power.The variation of particle density does not have impact substantially on radiant force.After supposing burning, particle expands, and it is large that particle diameter becomes, and emissivity reduces, and laser emission power so can not reduce substantially.When after burning, particle emissivity and particle diameter diminish simultaneously, laser emission power diminishes, and photophoresis power diminishes, and it is large that thermophoretic forces becomes, and drag force diminishes, and concrete varied number level need to be determined according to the result of calculation of design parameter.If radiant force is not enough to suspended particle, while making particle occur to be freely shifted, according to particle moving direction and displacement, can be by improving the energy of laser beam and adjusting focus point and solve.

Improve gradually and be radiated at the laser power on microparticle fuel 11, particle surface generating gasification, has Volatile, and when microparticle fuel surface temperature surpasses its kindling point, microparticle fuel is lighted and combustion reaction occurred.In Figure of description 2, the first laser instrument 2 is driven and controls by the first laser driver 1, and therefore in order to realize microparticle ignited fuel, the maximum power output of the first laser instrument 2 should reach several watts.

Microparticle fuel 11 need to be surveyed by an other light path in the position of micro-combustion chip 12, and its structural representation is shown in Figure of description 3.The light that second laser 4 sends arrives 4 quadrant detector 21 by the first reflective mirror 5, the first spectroscope 6, inverted telescope 7,8, the second spectroscope 9, high power objective 10, microparticle fuel 11, micro-combustion chip 12, condenser 14, the 3rd spectroscope 15, first lens 19, optical filter 20, obtain the position of microparticle fuel 11, second laser 4 is driven and is controlled by the second laser driver 3.According to the output of 4 quadrant detector, judge the position of microparticle fuel.When 4 quadrant detector is output as zero, represent that particulate, at the center of light beam, is assumed to be true origin; When the output non-zero of 4 quadrant detector, represent that particulate is offset, by arithmetic analysis, go out the coordinate position of particulate, can judge direction and position that particulate is offset.

Figure of description 4 is shown in by microparticle fuel and micro-combustion chip illumination schematic diagram, and the light that light source 18 sends carries out Uniform Illumination by collecting lens 17, iris 16, the 3rd spectroscope 15,14 pairs of micro-combustion chips of condenser 12.This lighting system is heart Kohler illumination far away, and collecting lens 17 is imaged onto light source 18 on the front focal plane of condenser 14, and iris 16 is placed on the object space focal plane of condenser 14, forms telecentric beam path in image space, and field stop is imaged onto on object plane by condenser.

Fig. 5 is shown in by the detection schematic diagram of microparticle fuel shape, particle diameter and surface temperature distribution, and illumination light is carried out imaging, particulate form and particle diameter and detected by high power objective 10, the second spectroscope 9, the second lens 22, the 3rd spectroscope 23 arrival CCD cameras 24; The infrared radiating light that particle burning sends arrives by high power objective 10, the second spectroscope 9, the second lens 22, the 3rd spectroscope 23, the second reflective mirror 25 that thermal cameras 26 carry out imaging and particulate Temperature Distribution detects; CCD camera 24 is directly taken microparticle fuel, according to photographic images, analyzes, and can obtain change of shape and the mean grain size of microparticle fuel in micro-combustion and gasification and change, and therefore can analyze burning and the gasification rate of microparticle fuel.Thermal camera 26 is taken the surperficial infrared intensity of microparticle fuel in burning and gasification, by Digital Image Processing, can obtain the Temperature Distribution of microparticle fuel surface.In conjunction with the shape and the particle size parameters that obtain, come analytic combustion and gasification property.

Claims (1)

1. one kind single particulate fuel micro-combustion, gasification suspends, imaging and detection system, it is characterized in that: comprise the first laser driver (1), the first laser instrument (2), the second laser driver (3), second laser (4), the first reflective mirror (5), the first spectroscope (6), inverted telescope (7, 8), the second spectroscope (9), high power objective (10), microparticle fuel (11), micro-combustion chip (12), three-D electric displacement platform (13), condenser (14), the 3rd spectroscope (15), iris (16), collecting lens (17), light source (18), first lens (19), optical filter (20), 4 quadrant detector (21), the second lens (22), the 3rd spectroscope (23), CCD camera (24), the second reflective mirror (25) and thermal camera (26),

The light that the first laser instrument (2) sends forms focal beam spot by the first spectroscope (6), inverted telescope (7,8), the second spectroscope (9) and high power objective (10) and carrys out microactuator suspension granular fuel (11); By output power to the microparticle fuel (11) that regulates the drive current of the first laser driver (1) to improve the first laser instrument (2), light; The infrared radiating light that particle burning sends arrives thermal camera (26) by high power objective (10), the second spectroscope (9), the second lens (22), the 3rd spectroscope (23), the second reflective mirror (25) and carries out imaging and the detection of particulate Temperature Distribution; Described microparticle fuel (11) is positioned in micro-combustion chip (12);

The light that second laser (4) sends arrives 4 quadrant detector (21) by the first reflective mirror (5), the first spectroscope (6), inverted telescope (7,8), the second spectroscope (9), high power objective (10), microparticle fuel (11), micro-combustion chip (12), condenser (14), the 3rd spectroscope (15), first lens (19), optical filter (20), obtain the position of microparticle fuel (11), second laser (4) is driven by the second laser driver (3) and controls;

The light that light source (18) sends carries out Uniform Illumination by collecting lens (17), iris (16), the 3rd spectroscope (15), condenser (14) to micro-combustion chip (12); Illumination light arrives CCD camera (24) by high power objective (10), the second spectroscope (9), the second lens (22), the 3rd spectroscope (23) and carries out imaging, particulate form and particle diameter detection.

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