Gas phase jet flow flame combustion and diagnosis experiment device

Abstract

The utility model relates to the technical field of online combustion flame diagnosis, and discloses a gas phase jet flow flame combustion and diagnosis experiment device which comprises a schlieren light source unit, a laser emission unit, a light splitting plain film, a schlieren detection unit and a fluorescence acquisition unit, and the light splitting plain film is used for splitting schlieren light and fluorescence light. In-situ observation characterization is carried out on the gas phase jet flow flame by coupling schlieren, autofluorescence and laser-induced fluorescence methods, synchronous measurement of laser-induced fluorescence and schlieren and synchronous measurement of flame autofluorescence and schlieren can be realized, and the method is particularly suitable for in-situ observation characterization and diagnosis of flame with an asymmetric structure.

Description

TECHNICAL FIELD

[0001] The utility model relates to online combustion flame diagnostic technical field discloses a gas phase jet flame combustion and diagnosis experimental device. BACKGROUND

[0002] At present, researchers have carried out experimental research on the aviation engine combustion flame by using in-situ method, but the related research still has deficiencies and needs to be further improved.

[0003] The patent "laser-induced fluorescence focusing schlieren system" can perform two-dimensional visualization characterization on the hypersonic combustion flow field, but cannot reveal the distribution of intermediate components.

[0004] The patent "tunable diode laser absorption spectrum measurement system and combustion diagnosis method based on it" can judge the combustion state in the ramjet combustion chamber by measuring the component absorption rate.

[0005] In addition, related researchers also carried out in-situ diagnosis on the combustion flame in research papers, and coupled the use of schlieren and laser-induced fluorescence methods, but their research usually places schlieren and laser-induced fluorescence in two different directions, that is, schlieren and fluorescence observation are performed in two directions intersecting with each other, which is acceptable for axisymmetric flames; but for asymmetric burners (such as multi-jet burners that need to arrange multiple combustion nozzles on a straight line when studying the interaction between flames), it is difficult to simultaneously obtain flame information in the same direction. UTILITY MODEL CONTENTS

[0006] The utility model aims at providing a gas phase jet flame combustion and diagnosis experimental device, which can realize synchronous measurement of laser-induced fluorescence and schlieren, as well as synchronous measurement of flame spontaneous fluorescence and schlieren, and is especially suitable for in-situ observation, characterization and diagnosis of flames with asymmetric structure.

[0007] In order to achieve the above technical effects, the utility model adopts the technical scheme of:

[0008] A gas phase jet flame combustion and diagnosis experimental device, comprising:

[0009] A schlieren light source unit, which is used to emit light to the combustion flame to produce schlieren on the flame;

[0010] A laser emission unit, which is used to emit laser signals to the combustion flame to induce the flame to produce fluorescence;

[0011] A light splitting flat sheet for splitting the schlieren light and the fluorescent light; the schlieren light is a schlieren signal generated by the schlieren light source unit irradiating the flame; the fluorescent light includes a first fluorescent signal induced by laser and a second fluorescent signal spontaneously generated by the flame;

[0012] A schlieren detection unit for collecting the schlieren signal after the light splitting of the light splitting flat sheet;

[0013] A fluorescent collection unit for receiving the first fluorescent signal and the second fluorescent signal after the light splitting of the light splitting flat sheet.

[0014] Further, the light of the schlieren light source unit acting on the flame is perpendicular to the laser light acting on the flame.

[0015] Further, the light splitting flat sheet is an optical device with a transmittance higher than 80% for ultraviolet 308nm light and a transmittance lower than 0.1% for visible light 520nm.

[0016] Further, the fluorescent collection unit includes an ultraviolet objective lens, an image intensifier and a first camera; the ultraviolet objective lens is used to collect the fluorescent light transmitted through the light splitting flat sheet, and the image intensifier is used to synchronize and amplify the fluorescent light collected by the ultraviolet objective lens and then transmit the synchronized and amplified signal to the first camera.

[0017] Further, the schlieren detection unit includes a blade and a second camera, and a first convex lens is arranged on the light signal transmission path between the blade and the light splitting flat sheet.

[0018] Further, the laser emission unit includes a nanosecond pulse laser, a first mirror, a second mirror, a dye laser, a third mirror, a fourth mirror, a convex spherical lens and a flat concave cylindrical lens arranged in sequence along the laser transmission path; the pump light provided by the nanosecond pulse laser is guided to the dye laser through the first mirror and the second mirror to form a tunable laser for the laser-induced fluorescence method, and the tunable laser emitted by the dye laser is guided through the third mirror and the fourth mirror, and is converted into a sheet light source by the convex spherical lens and the flat concave cylindrical lens to act on the flame to induce the fluorescence of the flame components.

[0019] Further, the schlieren light source unit includes an LED point light source, a second convex lens and a fifth mirror; the light emitted by the LED point light source is collimated by the second convex lens and reflected by the fifth mirror to the flame, and the schlieren signal generated by the schlieren light source unit irradiating the flame is reflected to the light splitting flat sheet by the fifth mirror.

[0020] Further, a third camera is further included, which is used to directly collect the light emission morphology of the flame.

[0021] Further, a control acquisition subsystem is further included for controlling the schlieren light source unit, the laser emission unit to generate corresponding optical signals, and controlling the schlieren detection unit and the fluorescence acquisition unit to acquire and transmit the corresponding optical signals.

[0022] Compared with the prior art, the utility model has the beneficial effects that: the utility model uses the schlieren, autofluorescence and laser-induced fluorescence method to in-situ observe and characterize the gas-phase jet flame, can realize the synchronous measurement of laser-induced fluorescence and schlieren, and the synchronous measurement of flame autofluorescence and schlieren, and is especially suitable for in-situ observation, characterization and diagnosis of the flame with asymmetric structure. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is the structure schematic view of gas-phase jet flame combustion and diagnosis experimental device in embodiment 1 or 2;

[0024] Figure 2 It is the structure schematic view of whole experimental device in embodiment 1 or 2

[0025] Figure 3 It is the structure schematic view of liquid fuel supply subsystem in embodiment 2;

[0026] Figure 4 It is the autofluorescence image of propane multi-jet flame in embodiment 2;

[0027] Figure 5 It is the schlieren image of propane multi-jet flame in embodiment 2;

[0028] Wherein, 1, combustion and detection subsystem;101, burner;1011, fuel jet pipe;1012, heating rod;1013, burner cover;1014, sintered plate;102, LED point light source;103, second convex lens;104, fifth reflector;105, light splitting flat sheet;106, first convex lens;107, blade;108, second camera;109, nanosecond pulse laser;110, first reflector;111, second reflector;112, dye laser;113, third reflector;114, fourth reflector;115, convex spherical lens;116, flat concave cylindrical lens;117, ultraviolet objective lens;118, image intensifier;119, first camera;120, third camera;2, fuel supply subsystem;3, air supply subsystem;4, control acquisition subsystem. DETAILED DESCRIPTION

[0029] The utility model will be described in further detail below in combination with the embodiments and drawings. However, this should not be understood as the scope of the above-mentioned subject matter of the utility model being limited to the following embodiments only, and any technology realized based on the content of the utility model falls within the scope of the utility model.

[0030] Embodiment 1

[0031] Referring to Figure 1 and Figure 2 , a gas-phase jet flame combustion and diagnosis experimental device comprises:

[0032] a schlieren light source unit for emitting light to a combustion flame to irradiate the flame to generate a schlieren;

[0033] a laser emission unit for emitting a laser signal to the combustion flame to induce the flame to generate fluorescence;

[0034] a spectrometer flat sheet 105 for spectrometrically analyzing the schlieren light and the fluorescence light; the schlieren light comprises a schlieren signal generated by the schlieren light source unit irradiating the flame; the fluorescence light comprises a first fluorescence signal induced by the laser and a second fluorescence signal spontaneously generated by the flame;

[0035] a schlieren detection unit for collecting the schlieren signal after the spectrometric analysis of the spectrometer flat sheet 105;

[0036] a fluorescence collection unit for receiving the first fluorescence signal and the second fluorescence signal after the spectrometric analysis of the spectrometer flat sheet 105.

[0037] In the embodiment, the in-situ observation and characterization of the gas-phase jet flame are realized by coupling the use of the schlieren, spontaneous fluorescence, and laser-induced fluorescence methods, which can realize the simultaneous measurement of the laser-induced fluorescence and the schlieren, and the simultaneous measurement of the spontaneous fluorescence of the flame and the schlieren, and is especially suitable for the in-situ observation and characterization and diagnosis of the flame with an asymmetric structure.

[0038] In the embodiment, the light of the schlieren light source unit acting on the flame is perpendicular to the laser light acting on the flame, and since the first fluorescence signal and the second fluorescence signal propagate in a direction perpendicular to the laser light and the schlieren signal propagates in a direction perpendicular to the light of the schlieren light source unit, the flame can be characterized and observed in-situ in the same direction, the simultaneous measurement of the laser-induced fluorescence and the schlieren in the same direction can be realized, and the simultaneous measurement of the spontaneous fluorescence of the flame and the schlieren in the same direction can be realized, and the embodiment is especially suitable for the in-situ observation and characterization and diagnosis of the flame with an asymmetric structure (such as a multi-jet burner).

[0039] The spontaneous fluorescence of the intermediate components in the flame and the laser-induced fluorescence of the components in the flame are mainly in the ultraviolet light band; therefore, the light plate 105 in the embodiment is selected to be an optical device with a transmittance of more than 80% to ultraviolet light of 308 nm and a transmittance of less than 0.1% to visible light of 520 nm, such as ZWB3 glass, to realize the synchronous observation of the flame schlieren and the fluorescence.

[0040] In the embodiment, the fluorescence acquisition unit includes an ultraviolet objective 117, an image intensifier 118, and a first camera 119; the ultraviolet objective 117 is used to acquire the fluorescence light transmitted through the light plate 105, and the image intensifier 118 is used to synchronize and amplify the fluorescence light acquired by the ultraviolet objective 117 and then transmit the synchronized and amplified signal to the first camera 119 (such as an industrial camera).

[0041] In the embodiment, the schlieren detection unit includes a blade 107 and a second camera 108 (such as an industrial camera), and a first convex lens 106 is arranged on the light signal transmission path between the blade 107 and the light plate 105; the blade 107 is used to block the direct light and retain the schlieren refracted light.

[0042] In the embodiment, the laser emission unit includes a nanosecond pulse laser 109, a first mirror 110, a second mirror 111, a dye laser 112, a third mirror 113, a fourth mirror 114, a convex spherical lens 115, and a flat concave cylindrical lens 116 arranged in sequence along the laser transmission path; the pump light provided by the nanosecond pulse laser is guided to the dye laser through the first mirror and the second mirror to form a tunable laser for the laser-induced fluorescence method, and the laser emitted by the dye laser 112 is guided through the third mirror 113 and the fourth mirror 114, and then converted into a sheet light source by the convex spherical lens 115 and the flat concave cylindrical lens 116 to act on the flame to induce the fluorescence of the components in the flame.

[0043] In the embodiment, the schlieren light source unit includes an LED point light source 102, a second convex lens 103, and a fifth mirror 104; the light emitted by the LED point light source 102 is collimated by the second convex lens 103 and reflected by the fifth mirror 104 to the flame, and the schlieren signal generated by the schlieren light source unit irradiating the flame is reflected to the light plate 105 by the fifth mirror 104.

[0044] In addition, the gas-phase jet flame combustion and diagnosis experimental device in the embodiment further includes a control acquisition subsystem, which is used to control the schlieren light source unit and the laser emission unit to generate corresponding optical signals, and control the schlieren detection unit and the fluorescence acquisition unit to acquire and transmit the corresponding optical signals.

[0045] Embodiment 2

[0046] As Figures 1-3 shown, the embodiment takes the combustion flame of liquid fuel as an example to explain the gas-phase jet flame combustion and diagnosis experimental device of the utility model in detail, and the overall experimental device can be divided into a combustion detection subsystem 1, a liquid fuel supply subsystem 2, an air supply subsystem 3 and a control collection subsystem 4.

[0047] The combustion detection subsystem 1, as Figure 2 shown, is mainly used for flame combustion and detection, and includes:

[0048] A burner 101, an LED point light source 102, a convex lens 103, a fifth mirror 104, a light splitting flat sheet 105, a convex lens 106, a blade 107, a second camera 108, a nanosecond pulse laser 109, a first mirror 110, a second mirror 111, a dye laser 112, a third mirror 113, a fourth mirror 114, a convex spherical lens 115, a flat concave cylindrical lens 116, an ultraviolet objective 117, an image intensifier 118, a first camera 119 and a third camera 120. The third camera 120 is used for directly collecting the flame light emission pattern.

[0049] As Figure 3 shown, the burner 101 can be used for the combustion of gaseous fuel and liquid fuel, and includes a fuel jet pipe 1011, a heating rod 1012, a burner cover 1013 and a sintered plate 1014. The heating rod 1012 is used for heating the burner and preheating air to avoid fuel condensation.

[0050] The light splitting flat sheet 105 realizes the coupling of the fluorescent light path and the schlieren light path, and has the characteristics of high transmittance in the ultraviolet waveband and high reflectivity in the visible light waveband.

[0051] The combustion detection subsystem 1 in the embodiment has two detection modes, in which:

[0052] In the first detection mode, laser-induced fluorescence and schlieren are measured in the same direction and synchronously. The schlieren light emitted by the LED point light source 102, collimated by the convex lens 103 and reflected by the fifth mirror 104 is reflected to the first convex lens 106 and the second camera 108 for schlieren detection at the light splitting flat sheet 105. The laser emitted by the dye laser 112 is guided by the third mirror 113, the fourth mirror 114, the convex spherical lens 115 and the flat concave cylindrical lens 116 to be converted into a sheet light source and act on the flame, thereby inducing the fluorescence of the flame components, which is mainly in the ultraviolet light waveband. The fluorescence is collected by the ultraviolet objective 117 and synchronously and amplified by the image intensifier 118, and then collected by the first camera 119.

[0053] In the second detection mode, the spontaneous fluorescence and the schlieren are measured in the same direction and synchronously: the schlieren is still measured in the same way as in the first detection mode; the spontaneous fluorescence of the intermediate components in the flame is mainly ultraviolet light, which is transmitted through the light splitting plate 105, collected by the ultraviolet objective 117, and amplified by the image intensifier 118, and then collected by the first camera 119.

[0054] The liquid fuel supply subsystem 2 in the embodiment is used to realize the supply, atomization and vaporization of liquid fuel, and includes a mass flow meter, a pressure gauge, a float flow meter, a liquid injection pump, a tee joint, a vaporization furnace and a pyrolysis furnace. The liquid fuel is stably supplied at a set flow rate by the injection pump, mixed with nitrogen carrier gas supplied by the mass flow meter at the tee joint, and then delivered to the vaporization furnace.

[0055] The vaporization furnace structure is used to realize the vaporization of liquid fuel, and includes a sealed furnace tube and a micro-porous atomization tube. The gas-liquid mixture from the tee joint is sprayed out of the micro-porous atomization tube to form tiny droplets, which are stably vaporized in the sealed furnace tube to realize the vaporization supply of liquid fuel at a large flow rate.

[0056] The air supply subsystem 3 in the embodiment is used to supply and control the flow rate of air, and can switch the air source to a compressed air cylinder or an air compressor. The air supply subsystem 3 includes an air cylinder, a mass flow meter, an air compressor, a cold dryer, a pressure stabilizing valve, an adjusting valve, a Roots flow meter, a pressure gauge and a float flow meter.

[0057] The control and collection subsystem 4 is used to interact with the combustion detection subsystem 1, the liquid fuel supply subsystem 2 and the air supply subsystem 3 respectively to realize the signal synchronous control and image collection, and includes a digital delay generator.

[0058] The gas-phase jet flame diagnosis method in the embodiment has the following process:

[0059] The first step is to optimize the schlieren light path, mainly to optimize the positions and angles of the LED point light source 102, the convex lens 103, the fifth mirror 104, the light splitting plate 105, the convex lens 106, the knife blade 107 and the second camera 108, to realize the normal imaging of the schlieren.

[0060] The second step is to optimize the spontaneous fluorescence light path, mainly to optimize the positions and angles of the ultraviolet objective 117, the image intensifier 118 and the first camera 119, to realize the normal imaging of the spontaneous fluorescence of the intermediate components in the flame.

[0061] The third step is to optimize the laser-induced fluorescence light path, mainly to optimize the positions and directions of the third mirror 113, the fourth mirror 114, the convex spherical lens 115 and the plane-concave cylindrical lens 116, to form a good sheet light source and to place the sheet light source at a reasonable position.

[0062] The fourth step is synchronization control and collection setting, mainly setting time resolution control parameters of the control collection subsystem 4, such as delay, pulse width, trigger, etc., to realize timing control of the industrial camera and the image intensifier 118;

[0063] The fifth step is setting temperature control of the vaporization furnace, the pyrolysis furnace and the burner, to realize reasonable control of the temperature of the heating rod 1012 of the vaporization furnace, the pyrolysis furnace and the burner, and avoid liquid fuel condensation.

[0064] The sixth step is setting air and liquid flow.

[0065] The seventh step is first detection mode collection.

[0066] The eighth step is second detection mode collection.

[0067] The flame is set to different working conditions, and the sixth to eighth steps are repeated, and synchronous collection of laser-induced fluorescence and schlieren and synchronous collection of spontaneous fluorescence and schlieren are realized.

[0068] In an embodiment of the patent, the light splitting flat sheet 105 adopts ZWB3 glass, which has a transmittance higher than 80% at ultraviolet 308 nm and a transmittance lower than 0.1% at visible light 520 nm.

[0069] In an embodiment of the patent, the propane flame is implemented with synchronous measurement of spontaneous fluorescence and schlieren in the same direction, i.e. the first detection mode, and the results are shown in Figure 4 、 Figure 5 , Figure 4 is a spontaneous fluorescence image of the propane multi-jet flame, Figure 5 is a schlieren image of the propane multi-jet flame; the flame is a propane three-jet flame, which can be used to study the interaction between jet flames, and the experimental device of the patent can be used to observe and characterize the change of the jet flame.

[0070] The above is only a preferred embodiment of the patent, and is not used to limit the patent, and any modification, equivalent replacement and improvement, etc. made within the spirit and principle of the patent should be included in the protection scope of the patent.

Claims

1. A gas phase jet flame combustion and diagnostics experimental apparatus, characterized by, It comprises: a schlieren light source unit for emitting light to the burning flame to irradiate the flame to generate schlieren; a laser emission unit for emitting laser signal to the burning flame to induce the flame to generate fluorescence; a light splitting flat sheet for splitting the schlieren light and the fluorescence light; the schlieren light is the schlieren signal generated by the schlieren light source unit irradiating the flame; the fluorescence light includes the first fluorescence signal induced by laser and the second fluorescence signal spontaneously generated by the flame; a schlieren detection unit for collecting the schlieren signal after the light splitting of the light splitting flat sheet; a fluorescence collection unit for receiving the first fluorescence signal and the second fluorescence signal after the light splitting of the light splitting flat sheet.

2. The gas-phase-jet-flame combustion and diagnostics experimental apparatus according to claim 1, wherein The light of the schlieren light source unit acting on the flame is perpendicular to the laser light acting on the flame.

3. The gas-phase-jet-flame combustion and diagnostics experimental apparatus according to claim 2, wherein, The light splitting flat sheet is an optical device with a transmittance higher than 80% to ultraviolet 308nm light and a transmittance lower than 0.1% to visible light 520nm.

4. The apparatus of claim 3, wherein, The fluorescence collection unit includes an ultraviolet objective lens, an image intensifier and a first camera; the ultraviolet objective lens is used to collect the fluorescence light transmitted through the light splitting flat sheet, and the image intensifier is used to synchronize and amplify the fluorescence light collected by the ultraviolet objective lens and then transmit the synchronized and amplified signal to the first camera.

5. The apparatus of claim 3, wherein, The schlieren detection unit includes a blade and a second camera, and a first convex lens is arranged on the light signal transmission path between the blade and the light splitting flat sheet.

6. The apparatus of claim 3, wherein, The laser emission unit includes a nanosecond pulse laser, a first mirror, a second mirror, a dye laser, a third mirror, a fourth mirror, a convex spherical lens and a flat concave cylindrical lens arranged in sequence along the laser transmission path; the pump light provided by the nanosecond pulse laser is guided to the dye laser through the first mirror and the second mirror to form a tunable laser for laser-induced fluorescence method, and the tunable laser emitted by the dye laser is guided through the third mirror and the fourth mirror, and then converted into a sheet light source by the convex spherical lens and the flat concave cylindrical lens to act on the flame to induce the fluorescence of the flame components.

7. The apparatus of claim 3, wherein the apparatus is configured to operate in a gas phase jet flame combustion and diagnostics mode. The schlieren light source unit includes an LED point light source, a second convex lens and a fifth mirror; the light emitted by the LED point light source is collimated by the second convex lens and reflected by the fifth mirror to the flame, and the schlieren signal generated by the schlieren light source unit irradiating the flame is reflected to the light splitting flat sheet by the fifth mirror.

8. The gas-phase-jet-flame combustion and diagnostics experimental apparatus according to claim 1, wherein It further comprises a third camera for directly collecting the light emission topography of the flame.

9. The apparatus according to any one of claims 1 to 8, wherein It further comprises a control collection subsystem for controlling the schlieren light source unit and the laser emission unit to generate corresponding optical signals, and controlling the schlieren detection unit and the fluorescence collection unit to collect and transmit the corresponding optical signals.

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