Flame visualization device, flame visualization system, and flame visualization method

Abstract

To provide a flame visualization device and a flame visualization method that can visualize a flame generated by combusting ammonia.SOLUTION: A flame visualization device 10 comprises: an imaging unit 20 that selectively detects light of an ultraviolet region emitted by NH radical generated through combustion of fuel including ammonia; and an output unit 30 that outputs images picked up by the imaging unit 20. The flame visualization method includes: an imaging step of selectively detecting light of an ultraviolet region emitted by NH radical generated through combustion of fuel including ammonia; and an output step of outputting images picked up in the imaging step.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a flame visualization device, a flame visualization system, and a flame visualization method. [Background technology]

[0002] Conventionally, furnace monitoring devices that use an imaging unit to monitor the combustion state inside a furnace are known. By checking the shape of the flame with the imaging unit, abnormalities inside the furnace can be detected in real time, and the abnormalities can be dealt with promptly. Patent Document 1 discloses an imaging unit installed at an in-furnace monitoring port, and visible light is guided to the imaging unit to capture an image of the state inside the furnace. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-138985 A Summary of the Invention [Problem to be solved by the invention]

[0004] For example, when a fuel containing a hydrocarbon such as heavy oil is burned, the flame can be confirmed by an imaging unit that captures visible light. However, in places where background radiation is large, such as inside a combustion furnace or boiler, it is difficult to visualize the ammonia combustion flame because it becomes indistinguishable from furnace wall radiation. In addition, when ammonia and a hydrocarbon are mixed and burned, the soot generated by the combustion of the hydrocarbon emits strong orange radiation, which is the same color as the ammonia flame, so it is difficult to visualize the ammonia combustion flame. Therefore, it has been difficult to monitor the combustion state of the flame generated by burning ammonia in such an environment.

[0005] Therefore, an object of the present disclosure is to provide a flame visualization device, a flame visualization system, and a flame visualization method that are capable of visualizing a flame generated by burning ammonia. [Means for solving the problem]

[0006] The flame visualization device according to the present disclosure includes an imaging unit that selectively detects ultraviolet light emitted by NH radicals generated by combustion of a fuel containing ammonia, and an output unit that outputs an image captured by the imaging unit.

[0007] The fuel may further comprise organic matter.

[0008] The fuel may further comprise a hydrocarbon.

[0009] The fuel may further comprise molecular hydrogen.

[0010] The flame visualization device may include a bandpass filter that blocks at least a part of the wavelength of ultraviolet light emitted by OH radicals generated by combustion and transmits ultraviolet light emitted by NH radicals generated by combustion. The imaging unit may capture an image of the flame generated by burning fuel through the bandpass filter.

[0011] The bandpass filter may block 90% or more of light having a wavelength of 300 nm or more and 320 nm or less over the entire wavelength range.

[0012] The bandpass filter may transmit 90% or more of at least any light within a wavelength range of more than 320 nm and not more than 350 nm.

[0013] The bandpass filter may block 90% or more of light having a wavelength of 380 nm or more and 1200 nm or less over the entire wavelength range.

[0014] The flame visualization device may further include an infrared shielding filter that blocks 90% or more of light having a wavelength of 780 nm or more and 5000 nm or less over the entire wavelength range. The imaging unit may image the flame generated by the combustion of the fuel through the infrared shielding filter.

[0015] A flame visualization system according to the present disclosure includes a combustion section that combusts a fuel containing ammonia, and a flame visualization device.

[0016] The flame visualization method according to the present disclosure includes an imaging step of selectively detecting ultraviolet light emitted by NH radicals produced by combustion of a fuel containing ammonia, and an output step of outputting an image captured in the imaging step. Effect of the Invention

[0017] According to the present disclosure, it is possible to provide a flame visualization device, a flame visualization system, and a flame visualization method capable of visualizing a flame generated by burning ammonia. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram illustrating a flame visualization system according to an embodiment. [Diagram 2] 4 is a spectrum of the spectral sensitivity characteristics of an imaging unit in the example. [Diagram 3] 1 is a transmission spectrum of a bandpass filter according to an embodiment. [Figure 4] 4 is a transmission spectrum of an infrared shielding filter according to an embodiment. [Diagram 5] This is an image taken from the front of a flame generated by burning ammonia. [Figure 6] This is an image taken from the front of the flame generated by co-firing ammonia and heavy oil A. [Figure 7] This is an image taken from the side of the flame generated by the mono-combustion of ammonia. [Figure 8] This is an image taken from the side of a flame generated by co-firing ammonia and heavy oil A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, some exemplary embodiments will be described with reference to the drawings. Note that the dimensional ratios of the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios.

[0020] The flame visualization system 1 according to this embodiment is a system for visualizing a flame generated by the combustion of ammonia. As will be described later, the flame visualization system 1 visualizes an ammonia combustion flame by observing NH radicals generated by the combustion of ammonia. As shown in FIG. 1, the flame visualization system 1 according to this embodiment includes a combustion unit 5 and a flame visualization device 10.

[0021] The combustion section 5 burns a fuel containing ammonia. The combustion section 5 may include a burner 6, and a flame 7 is generated by burning the fuel containing ammonia with the burner 6. Ammonia does not contain carbon in its molecules, so it does not generate carbon dioxide when burned. Therefore, by including ammonia in the fuel, it is possible to reduce the amount of carbon dioxide emitted into the atmosphere. The fuel burned in the combustion section 5 may contain other fuels in addition to ammonia. That is, the fuel may be burned by burning ammonia alone or may be burned together with ammonia.

[0022] The fuel may further include an organic substance in addition to ammonia. The fuel may specifically include a carbon-containing fuel. The fuel may include at least one carbon-containing fuel selected from the group consisting of carbon particles, LNG (liquefied natural gas), LPG (liquefied petroleum gas), light oil, heavy oil, and biomass. The fuel may specifically include a hydrocarbon in addition to ammonia. The fuel may include at least one of an alkane and an alkene. The fuel may include one or more hydrocarbons having a carbon number of 1 to 100. The fuel may include methane, ethane, propane, butane, ethylene, propylene, or the like. The fuel may include a liquid fuel that is liquid at room temperature, such as 25° C., or may include a solid fuel that is solid at room temperature, such as 25° C.

[0023] The fuel may further contain hydrogen molecules in addition to ammonia. Like ammonia, hydrogen does not contain carbon in its molecules, so that it is possible to reduce the amount of carbon dioxide emitted into the atmosphere. In addition, hydrogen obtained by electrolyzing water using renewable energy such as solar, wind, and hydraulic power can be used, so that it is possible to reduce the amount of carbon dioxide emitted into the atmosphere.

[0024] The flame visualization device 10 is a device for visualizing a flame produced by the combustion of ammonia. The flame visualization device 10 includes an imaging unit 20, a bandpass filter 21, an infrared shielding filter 22, and an output unit 30.

[0025] The imaging unit 20 selectively detects ultraviolet light emitted by NH radicals. NH radicals are generated by the combustion of fuel containing ammonia. When the background radiation is large or the radiation light of soot is strong, the flame generated by burning ammonia has a relatively low brightness, and it is difficult to visualize it with a normal camera that captures visible light. In particular, when a substance containing carbon, such as an organic substance, is burned, OH radicals, CH radicals, C2 radicals, and the like are present in the generated flame. These radicals emit light when returning from an excited state to a stable state. For example, OH radicals emit light with a light intensity in the wavelength range of 300 nm to 327 nm, with a peak top at about 309 nm. In addition, CH radicals and C2 radicals emit light with a band spectrum in the visible range. In addition, in places such as combustion furnaces, light in the visible and infrared ranges is also emitted by thermal radiation. Therefore, with conventional methods, it is difficult to visualize the state of the flame generated by the combustion of ammonia, which has been a major challenge in the technological development of ammonia combustion toward decarbonization of the energy field.

[0026] On the other hand, the NH radical emits light having a chemiluminescence peak at about 336 nm due to the NH (0,0) band transition. Also, the NH radical emits light having a chemiluminescence peak at 337 nm due to the NH (1,1) band transition, which is smaller than the chemiluminescence peak due to the NH (0,0) band transition. The imaging unit 20 selectively detects the ultraviolet light emitted by the NH radical, and therefore can separate the light from the OH radical, H2O, soot, and other substances in the flame. Therefore, it is possible to visualize the flame generated by the combustion of ammonia. That is, the flame visualization device 10 can visualize the flame generated by the combustion of ammonia by, for example, blocking light derived from OH radicals and selectively detecting only the light emitted by the NH radical. The imaging unit 20 may capture images while blocking light in the visible and infrared ranges.

[0027] The imaging unit 20 includes an image sensor having sensitivity in the ultraviolet region. The image sensor can selectively detect ultraviolet light emitted by NH radicals. The image sensor may include a condenser lens, a light transmission filter, and a photoelectric conversion unit such as a photodiode. The condenser lens can collect light in the photodiode. The light transmission filter can transmit specific light, block specific light, and selectively transmit light having a desired wavelength. The photoelectric conversion unit receives light and converts the received light into an electrical signal such as a current or voltage according to its intensity.

[0028] The image sensor may be a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The image sensor has wavelength characteristics in the ultraviolet region. The image sensor may be sensitive to ultraviolet light emitted by NH radicals. Specifically, the image sensor may be sensitive to light within a wavelength range including at least one of approximately 336 nm and approximately 337 nm.

[0029] The imaging unit 20 may include a movable lens that adjusts the focal length. Such a movable lens allows a stereoscopic flame image to be captured, making it possible to visualize the flame in three dimensions.

[0030] In this embodiment, the imaging unit 20 captures an image of a flame generated by burning fuel through the bandpass filter 21 and the infrared shielding filter 22. Therefore, in this embodiment, the imaging unit 20 selectively detects ultraviolet light emitted by NH radicals through the bandpass filter 21 and the infrared shielding filter 22. In this specification, the wavelength of the visible range is equal to or greater than 380 nm and less than 780 nm, and the wavelength of the infrared range is equal to or greater than 780 nm.

[0031] The bandpass filter 21 may block at least a part of the wavelength of ultraviolet light emitted by OH radicals generated by combustion. The light emitted by OH radicals has an intensity in a wavelength range of 300 nm to 327 nm with a peak top at about 309 nm. OH radicals are generated by, for example, the combustion of organic matter or hydrogen. Therefore, by blocking a part of the light emitted by OH radicals, it is possible to prevent the light emitted by the combustion of fuels other than ammonia from being detected by the imaging unit 20.

[0032] The light emitted by the OH radical has an intensity within a wavelength range of 300 nm to 327 nm, but the intensity is weak at the base of the peak. Therefore, the bandpass filter 21 may block at least a part of the wavelength of the ultraviolet light emitted by the OH radical. For example, the bandpass filter 21 may block 90% or more of light having a wavelength of 300 nm or more and 320 nm or less over the entire wavelength range. The above wavelength range may be 250 nm or more or 200 nm or more instead of 300 nm or more. The above wavelength range may be 324 nm or less or 327 nm or less instead of 320 nm or less. The bandpass filter 21 may block 95% or more, 99% or more, or 99.9% or more of the light within the above range over the entire wavelength range.

[0033] The bandpass filter 21 transmits ultraviolet light emitted by NH radicals generated by combustion. NH radicals emit light with peaks at 336 nm and 337 nm. Therefore, the bandpass filter 21 may transmit 90% or more of at least any light within a wavelength range of more than 320 nm and not more than 350 nm. By transmitting light within such a wavelength range through the bandpass filter 21, the imaging unit 20 can adequately detect the light emitted by the NH radicals.

[0034] Although the wavelength range is set to be more than 320 nm, the wavelength may be 328 nm or more, or 335 nm or more. Although the wavelength range is set to be 350 nm or less, the wavelength may be 347 nm or less, 343 nm or less, or 339 nm or less. The bandpass filter 21 may transmit at least 90% of light of, for example, about 336 nm, which is the peak of chemiluminescence due to NH(0,0) band transition, and about 337 nm, which is the peak of chemiluminescence due to NH(1,1) band transition. The bandpass filter 21 may transmit 40% or more, or 45% or more of light of wavelengths of 332 nm or more and 342 nm or less over the entire wavelength range.

[0035] The bandpass filter 21 may block 90% or more of light having a wavelength of 380 nm or more and 1200 nm or less across the entire wavelength range. When a carbon-containing fuel is burned, CH radicals and C2 radicals are generated, and light having a spectrum in the visible range is emitted. In addition, from an object that has become hot due to combustion, light in the visible range and infrared range is also emitted by thermal radiation. Therefore, by blocking 90% or more of light having a wavelength of 380 nm or more and 1200 nm or less across the entire wavelength range, it is possible to suppress the detection of such light by the imaging unit 20. In addition, the bandpass filter 21 may block 95% or more of light having a wavelength of 380 nm or more and 1200 nm or less across the entire wavelength range, or may block 99% or more, or may block 99.9% or more.

[0036] The infrared shielding filter 22 transmits light emitted by NH radicals, similarly to the bandpass filter 21. That is, the infrared shielding filter 22 may transmit 70% or more of at least any light within a wavelength range of 320 nm to 350 nm. By transmitting light within such a wavelength range through the infrared shielding filter 22, the imaging unit 20 can adequately detect the light emitted by the NH radicals. The infrared shielding filter 22 may transmit 70% or more of light within the entire wavelength range of 320 nm to 350 nm. Although the wavelength range of the infrared shielding filter 22 is set to 320 nm or more, the wavelength may be 328 nm or more or 335 nm or more. Furthermore, although the wavelength range of the infrared shielding filter 22 is set to 350 nm or less, the wavelength may be 347 nm or less, 343 nm or less, or 339 nm or less.

[0037] The infrared shielding filter 22 may block 90% or more of light in the entire wavelength range of 380 nm or more and 5000 nm or less. Such an infrared shielding filter 22 can suppress the influence of heat, block light in the visible and infrared ranges, and prevent such light from being detected by the imaging unit 20. The infrared shielding filter 22 may block 95% or more of light in the entire wavelength range of 390 nm or more and 5000 nm or less.

[0038] The infrared shielding filter 22 may block 90% or more of light having a wavelength of 780 nm or more and 5000 nm or less across the entire wavelength range. When light having such a wavelength range is absorbed by an object, the object heats up due to molecular vibration. Therefore, the infrared shielding filter 22 can block light in the infrared range and suppress the influence of heat. Furthermore, light in the infrared range is emitted by thermal radiation from an object that has become hot due to combustion. Therefore, the infrared shielding filter 22 can suppress such light from being detected by the imaging unit 20. The infrared shielding filter 22 may block 95% or more of light having a wavelength of 780 nm or more and 5000 nm or less across the entire wavelength range, or may block 98% or more of light having a wavelength of more than 5000 nm and 1 mm or less. The infrared shielding filter 22 may block light having a wavelength of more than 5000 nm and 1 mm or less, similar to light having a wavelength of 780 nm or more and 5000 nm or less.

[0039] The output unit 30 outputs the video captured by the imaging unit 20. The output unit 30 is electrically connected to the imaging unit 20. The output unit 30 may be, for example, a liquid crystal display or a CRT. Note that, although the imaging unit 20 and the output unit 30 are depicted as separate, different units in FIG. 1, the imaging unit 20 and the output unit 30 may be an integrated unit.

[0040] 1, the bandpass filter 21 is disposed closer to the imaging section 20 than the infrared shielding filter 22. However, the infrared shielding filter 22 may be disposed closer to the imaging section 20 than the bandpass filter 21.

[0041] In the present embodiment, the flame visualization device 10 includes one bandpass filter 21 and one infrared shielding filter 22. However, the flame visualization device 10 may include a plurality of bandpass filters 21. The plurality of bandpass filters 21 may be formed by combining filters of the same type or by combining filters of different types. The flame visualization device 10 may include a plurality of infrared shielding filters 22. The plurality of infrared shielding filters 22 may be formed by combining filters of the same type or by combining filters of different types. By combining filters of the same type, it is possible to more strongly shield light of a wavelength that is shielded by the filter. By combining filters of different types, it is possible to transmit or shield a desired wavelength.

[0042] In the present embodiment, an example has been described in which the flame visualization device 10 includes the imaging unit 20, the bandpass filter 21, and the infrared shielding filter 22. However, if the imaging unit 20 can selectively detect light in the ultraviolet region emitted by the NH radical, the ammonia combustion flame can be visualized. Therefore, the bandpass filter 21 and the infrared shielding filter 22 are not essential components. For example, if the image sensor of the imaging unit 20 detects light of a wavelength emitted by the NH radical and has a lower sensitivity to other wavelengths than the sensitivity to light of a wavelength emitted by the NH radical, the ammonia combustion flame can be visualized.

[0043] The flame visualization device 10 may also include at least one of a bandpass filter 21 and an infrared shielding filter 22. For example, the flame visualization device 10 may include a bandpass filter 21 that blocks at least a part of the wavelength of ultraviolet light emitted by OH radicals generated by combustion and transmits ultraviolet light emitted by NH radicals generated by combustion. The imaging unit 20 may image a flame generated by burning fuel through the bandpass filter 21. The flame visualization device 10 may also include an infrared shielding filter 22 that blocks 90% or more of light with a wavelength of 780 nm or more and 5000 nm or less over the entire wavelength range. The imaging unit 20 may image a flame generated by burning fuel through the infrared shielding filter 22.

[0044] As described above, the flame visualization device 10 according to this embodiment includes the image capturing unit 20 that selectively detects ultraviolet light emitted by NH radicals generated by the combustion of fuel containing ammonia, and the output unit 30 that outputs an image captured by the image capturing unit 20.

[0045] Moreover, the flame visualization method according to this embodiment includes an imaging step of selectively detecting ultraviolet light emitted from NH radicals produced by the combustion of fuel containing ammonia, and an output step of outputting an image captured in the imaging step.

[0046] A flame generated by burning ammonia has a relatively low brightness when the background radiation is large or when the radiation light from soot is strong, and it is difficult to visualize the flame with a normal camera that captures visible light. However, the flame visualization device 10 and the flame visualization method according to the present embodiment selectively detect the light emitted by the NH radical generated by the combustion of ammonia. Therefore, the flame visualization device 10 and the flame visualization method according to the present embodiment can visualize the flame generated by burning ammonia.

[0047] According to the flame visualization device 10 and the flame visualization method of the present embodiment, it is possible to visualize an ammonia combustion flame. Therefore, by checking the spread and fluctuation of the ammonia combustion flame, it is possible to detect an abnormality in the furnace in real time and to quickly respond to the abnormality. EXAMPLES

[0048] The present embodiment will now be described in more detail with reference to the following examples, but the present embodiment is not limited to these examples.

[0049] First, the following imaging section, band-pass filter, and infrared blocking filter were prepared.

[0050] (Imaging unit) Sold by: Artray Co., Ltd. Product name: ARTCAM-487UV Detection wavelength range: 200nm~1000nm Sensor: CMOS (Sony) with sensitivity in the ultraviolet range Spectral sensitivity characteristics: The imaging unit detects light in the wavelength range of 328nm to 347nm, and the relative sensitivity in the wavelength range of 328nm to 347nm in the wavelength range of 200nm to 1000nm is 50% to 60% (see Figure 2). Figure 2 is a diagram created by tracing the spectrum of the spectral sensitivity characteristics of ARTCAM-487UV published by Artray Co., Ltd.

[0051] (Bandpass filter) Sold by: Edmund Optics Product name: TS OD 4.0 10nm Bandpass Filter 337nm 25mm Center wavelength: 337.00nm±2.0nm FWHM: 10.00 nm ± 2.0 nm Blocking range: 200nm~1200nm Material: Hard-coated 3.5mm±0.5mm thick optical glass substrate

[0052] Figure 3 is a diagram created by tracing the transmission spectrum of the above bandpass filter published by Edmund Optics. As shown in Figure 3, the transmission spectrum of the bandpass filter has a single peak with a central wavelength of 337 nm. The bandpass filter transmits 45% or more of light with a wavelength of 332 nm or more and 342 nm or less across the entire wavelength range. The bandpass filter also transmits 90% or more of light with a wavelength of 337 nm. In addition, the transmittance of the above spectrum in the range of 200 nm or more and 327 nm or less and the range of 347 nm or more and 1200 nm or less is 0.1% or less at all wavelengths.

[0053] (Infrared shielding filter) Sold by: HOYA Corporation Product name: UV transmission / visible absorption filter U340 Thickness: 2.50mm

[0054] Fig. 4 shows the transmittance of U340 published by HOYA Corporation. As shown in Fig. 4, the infrared shielding filter transmits 70% or more of light with wavelengths of 320 nm or more and 350 nm or less across the entire wavelength range. The infrared shielding filter blocks 97% or more of light with wavelengths of 200 nm to 260 nm and 390 nm to 5000 nm across the entire wavelength range. The infrared shielding filter also blocks 99% or more of light with wavelengths of 200 nm to 260 nm, 390 nm to 690 nm, 740 nm to 2550 nm, and 2800 nm to 5000 nm across the entire wavelength range.

[0055] Next, one bandpass filter and two infrared shielding filters were attached to the imaging unit, and the flame was imaged through these bandpass filters and infrared shielding filters. Fig. 5 is an image of a flame generated by mono-combustion of ammonia, imaged from the front. Fig. 6 is an image of a flame generated by co-combustion of ammonia and heavy oil A, imaged from the front. Fig. 7 is an image of a flame generated by mono-combustion of ammonia, imaged from the side. Fig. 8 is an image of a flame generated by co-combustion of ammonia and heavy oil A, imaged from the side.

[0056] In Fig. 5, a burner is placed in the center, and ammonia is injected in six directions from the center outward. As shown in Fig. 5, the flame visualization device according to the embodiment selectively detects light emitted by NH radicals. Therefore, ammonia before combustion is black, but NH radicals generated by the combustion of ammonia are output in white.

[0057] In addition, as shown in Figure 6, the flame generated by the combustion of ammonia could also be visualized in the flame generated by the co-combustion of ammonia and heavy oil A. In Figure 6, the radial streaks in the center indicate the state in which heavy oil A was sprayed. Heavy oil A does not generate NH radicals, so it appears black. Furthermore, as shown in Figures 7 and 8, it was confirmed that the flame generated by the combustion of ammonia could be visualized by imaging the side of the flame.

[0058] From the above results, it was confirmed that the flame visualization device and the flame visualization method according to the present embodiment can visualize a flame generated by burning ammonia.

[0059] Although several embodiments have been described, the embodiments can be modified or modified based on the above disclosure. All components of the above embodiments and all features described in the claims may be individually extracted and combined as long as they are not mutually inconsistent.

[0060] This disclosure can, for example, contribute to Goal 7 of the United Nations-led Sustainable Development Goals (SDGs), "Ensure access to affordable, reliable, sustainable and modern energy." [Explanation of symbols]

[0061] 1. Flame Visualization System 5 Combustion section 10 Flame visualization device 20 Imaging unit 21 Bandpass Filter 22 Infrared shielding filter

Claims

1. A combustion unit that burns a fuel containing ammonia and at least one of an organic substance and a hydrogen molecule; A flame visualization device; 1. A flame visualization system comprising: The flame visualization device includes: an imaging unit that selectively detects ultraviolet light emitted by NH radicals generated by the combustion of the fuel; an output unit that outputs the image captured by the imaging unit; A flame visualization system comprising:

2. The flame visualization system of claim 1 , wherein the fuel further comprises a hydrocarbon.

3. a bandpass filter that blocks at least a portion of the wavelength of ultraviolet light emitted by OH radicals produced by the combustion and transmits ultraviolet light emitted by NH radicals produced by the combustion; The flame visualization system according to claim 1 , wherein the imaging section images the flame generated by the combustion of the fuel through the bandpass filter.

4. 4. The flame visualization system according to claim 3, wherein the bandpass filter blocks 90% or more of light having a wavelength of 300 nm or more and 320 nm or less over an entire wavelength range.

5. 4. The flame visualization system according to claim 3, wherein the bandpass filter transmits 90% or more of at least any light having a wavelength in the range of more than 320 nm and not more than 350 nm.

6. 4. The flame visualization system according to claim 3, wherein the bandpass filter blocks 90% or more of light having a wavelength of 380 nm or more and 1200 nm or less over an entire wavelength range.

7. Further comprising an infrared shielding filter that blocks 90% or more of light having a wavelength of 780 nm or more and 5000 nm or less over the entire wavelength range; The flame visualization system according to claim 1 , wherein the imaging section images the flame generated by the combustion of the fuel through the infrared shielding filter.

8. A method for producing a fuel comprising: burning ammonia and at least one of an organic substance and hydrogen molecules; an imaging step of selectively detecting ultraviolet light emitted by NH radicals produced by the combustion of the fuel; an output step of outputting the image captured in the imaging step; A flame visualization method comprising:

Images