Gas turbine combustion flame detection device based on excited-state free radical self-luminescence

Abstract

The utility model belongs to the technical field of flame detection, and particularly relates to a gas turbine combustion flame detection device based on excited-state free radical self-illumination, which comprises a signal filtering device and a photomultiplier, and the signal filtering device comprises a flame detection end, a flange pressing block and a PMT connecting end, communicated through holes are formed in the flame detection end, the flange pressing block and the PMT connecting end and are used for passing and filtering of optical signals; the flame detection end is connected with the interior of to-be-detected equipment, and flames exist in the to-be-detected equipment; the flame detection end is used for receiving light emitted by flame; an optical filter is arranged between the flange pressing block and the PMT connecting end; and the PMT connecting end is connected with the photomultiplier tube. The flame detector can accurately detect flame characteristics and is low in cost.

Description

Technical Field

[0001] The utility model belongs to the technical field of flame detection, and particularly relates to a gas turbine combustion flame detection device based on the self-luminescence of excited state free radicals. Background Technique

[0002] During the combustion process of fuel, the flame radiation spectrum includes ultraviolet, visible, and infrared bands. The radiation luminescence of free radicals is a phenomenon in which the non-steady electrons of free radicals generated by reactions in the flame transition and emit light of a specific wavelength. It is a kind of spontaneous radiation phenomenon, also called chemiluminescence. In chemiluminescence, the spontaneous radiation measurement of excited state free radicals generated through chemical excitation pathways has been widely used to evaluate flame characteristics. Currently, various intermediate products have been detected in the measurement of hydrocarbon combustion processes, and the main free radicals among them are: OH-, etc. The chemiluminescence emitted by excited chemical free radicals in the flame can be applied to the combustion diagnosis of gas turbines, aeroengines, internal combustion engines, combustion bombs, burners, turbines, and other facilities.

[0003] Commonly used excited state free radical detection devices include planar laser-induced fluorescence, high-speed camera image intensifiers, ICCD cameras, etc. However, these devices are large in size, very precise, have complex optical paths, and their costs range from tens of thousands to millions of yuan, and they can only be used in specific occasions.

[0004] A photomultiplier tube (PMT) is a device used to detect optical signals and convert them into electrical signals. Its working principle is to convert photons into electrons through the photoelectric effect and enhance the signal intensity through a multi-stage electron multiplication process. Photomultiplier tubes are widely used in the measurement of low light intensities. In some industrial combustion devices (such as boilers, gas turbines, etc.), the shape and structure of the flame directly affect the combustion efficiency and emission levels. PMT can be used to measure the light intensity distribution of the flame, thereby analyzing the morphological characteristics of the flame (such as the shape of the flame front, the size of the flame, the distribution of the flame, etc.). Through this analysis, it can help optimize the design and operating conditions of the burner.

[0005] Compared with the excited state free radical capture devices mentioned above, the price of PMT is only a few thousand yuan. However, if PMT is directly used for flame detection, due to the extremely complex types of free radicals in the flame and the very wide spectral range involved, in addition, during the combustion process, the shape, intensity, and distribution of combustion products of the flame are usually locally and dynamically changing. When directly used for detection, the spectral signals are very chaotic, and it is also impossible to accurately diagnose combustion behaviors such as the start of combustion. Content of the Utility Model

[0006] In order to accurately measure the characteristics of the flame under low-cost conditions, the utility model provides a gas turbine combustion flame detection device based on the self-luminescence of excited state free radicals.

[0007] To achieve the above object, the technical solution of the present utility model is as follows:

[0008] A gas turbine combustion flame detection device based on the self-luminescence of excited-state free radicals, comprising a signal filtering device and a photomultiplier tube. The signal filtering device includes a flame detection end, a flange pressing block, and a PMT connection end. Through holes communicating with each other are provided inside the flame detection end, the flange pressing block, and the PMT connection end for the passage and filtering of optical signals.

[0009] The flame detection end is connected to the inside of the device to be detected, and there is a flame inside the device to be detected. The flame detection end is used to receive the light emitted by the flame. A filter is provided between the flange pressing block and the PMT connection end. The PMT connection end is connected to the photomultiplier tube.

[0010] Further, the flame detection end includes, from left to right, a first boss, a second boss, and a connecting flange with gradually increasing diameters. The first boss extends deep into the device to be detected; the connecting flange is connected to the flange pressing block.

[0011] Furthermore, the length of the first boss is the same as the wall thickness of the device to be detected.

[0012] Furthermore, a light spot hole is provided on the left end face of the first boss, and the aperture of the light spot hole is 1 mm.

[0013] Furthermore, a thread is provided on the outer surface of the second boss.

[0014] Furthermore, a cooling device is provided outside the second boss.

[0015] Further, the inside of the flame detection end is provided with a first hole, a second hole, and a third hole with gradually increasing diameters from left to right. The first hole is a light hole; the left end of the flange pressing block extends deep into the third hole.

[0016] Further, the through hole inside the flange pressing block has the same aperture as the light spot hole.

[0017] Further, there is a receiving space between the left end of the flange pressing block and the bottom wall of the third hole. Quartz glass is provided in the receiving space, and sealing gaskets are provided on both sides of the quartz glass.

[0018] Further, the inside of the PMT connection end is provided with a fourth hole, a fifth hole, and a sixth hole with gradually decreasing diameters from left to right. The right end of the flange pressing block extends deep into the fourth hole, and there is a receiving space between the right end of the flange pressing block and the bottom wall of the fourth hole. The filter is provided in the receiving space, and sealing gaskets are provided on both sides of the filter.

[0019] Further, a connecting thread is provided on the outer wall on the right side of the PMT connection end.

[0020] Compared with the prior art, the utility model has the following beneficial effects:

[0021] The gas turbine combustion flame detection device based on the self-luminescence of excited-state free radicals provided by the utility model first filters the signal through a signal filtering device, making the wavelength band of the free radical radiation light of the flame single, avoiding inaccurate flame detection caused by complex optical signals. The filtered light is detected by a photomultiplier tube to detect the characteristics of the light, thereby achieving the purpose of flame detection. There is no need to use expensive excited-state free radical detection equipment, and the cost is low. Description of the Drawings

[0022] Figure 1 It is a schematic structural diagram of the signal filtering device provided by an embodiment of the utility model.

[0023] Figure 2 It is a schematic internal structure diagram of the signal filtering device provided by an embodiment of the utility model.

[0024] Description of the Reference Numerals:

[0025] 1. Flame detection end, 101. First boss, 102. Second boss, 103. Connecting flange, 104. Spot hole, 105. First hole, 106. Second hole, 107. Third hole

[0026] 2. Flange pressing block, 3. PMT connection end, 301. Fourth hole, 302. Fifth hole, 303. Sixth hole

[0027] 4. Quartz glass, 5. Sealing gasket, 6. Filter Detailed Embodiment

[0028] The technical solution of the utility model will be clearly described below in conjunction with the description of the drawings. Obviously, the described embodiments are not all embodiments of the utility model. All other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the utility model.

[0029] It should be noted that unless otherwise specifically stated, the relative arrangements of components and steps described in these embodiments and numerical expressions should not be construed as limiting the scope of the utility model.

[0030] The following description of the exemplary embodiments is merely illustrative and in no way restricts the utility model and its application or use. Technologies, methods, and devices known to those of ordinary skill in the relevant fields may not be discussed in detail here, but when applicable, these technologies, methods, and devices should be regarded as part of this specification.

[0031] This embodiment provides a gas turbine combustion flame detection device based on the self-luminescence of excited-state free radicals, as Figure 1 and Figure 2 shown, which includes a signal filtering device and a photomultiplier tube. The signal filtering device includes a flame detection end 1, a flange pressing block 2, and a PMT connection end 3. Through holes that are connected are provided inside the flame detection end 1, the flange pressing block 2, and the PMT connection end 3 for the passage and filtering of optical signals;

[0032] The flame detection end 1 is connected to the inside of the device to be detected, and there is a flame inside the device to be detected; the flame detection end 1 is used to receive the light emitted by the flame; a filter 6 is provided between the flange pressing block 2 and the PMT connection end 3; the PMT connection end 3 is connected to the photomultiplier tube.

[0033] Among them, the flame detection end 1 includes a first boss 101, a second boss 102, and a connecting flange 103 with diameters increasing in sequence from left to right. The first boss 101 extends deep into the inside of the device to be detected; the connecting flange 103 is connected to the flange pressing block 2. The length of the first boss 101 is the same as the wall thickness of the device to be detected to reduce the damage to the internal flow field of the original device caused by changing the device.

[0034] Threads are provided on the outer surface of the second boss 102 for threaded connection with the outer shell of the device to be detected. The second boss 102 is also used to prevent structural interference when the gas turbine combustion flame detection device is connected to the device to be detected, and the length of the second boss 102 can be adjusted according to actual needs. In addition, a cooling device can be provided on the outside of the second boss 102 to prevent the high-temperature combustion gas from damaging the PMT through heat conduction.

[0035] As Figure 2 shown, a light spot hole 104 is provided on the left end face of the first boss 101, and the aperture of the light spot hole 104 is 1 mm. The light spot hole 104 is used to filter background light mixed noise signals, centrally receive the light emitted by the flame, enhance the signal intensity, capture rapidly changing local features, thereby improving the time resolution and the accuracy of the measurement results.

[0036] Inside the flame detection end 1, a first hole 105, a second hole 106, and a third hole 107 with diameters increasing in sequence from left to right are provided. The first hole 105 is a light hole; the left end of the flange pressing block 2 extends deep into the third hole 107.

[0037] The first hole 105 is a through hole for ensuring the linear propagation of light. At the same time, it is convenient for processing and can also ensure that when the material has a certain deformation, the light can still propagate in a straight line. The second hole 106 is for reducing the wall thickness and ensuring the heat dissipation of the material.

[0038] Both sides of the flange pressing block 2 are provided with steps. The left end extends into the third hole 107 to ensure the coaxiality between the flange pressing block 2 and the flame detection end 1 and play a pressing role. The right end extends into the PMT connection end 3 to ensure the coaxiality between the flange pressing block 2 and the PMT connection end 3. The aperture of the through hole inside the flange pressing block 2 is the same as that of the light spot hole 104.

[0039] There is an accommodation space between the left end of the flange pressing block 2 and the bottom wall of the third hole 107. A quartz glass 4 is arranged in the accommodation space, and sealing gaskets 5 are arranged on both sides of the quartz glass 4. Since the combustion environment is usually a high-temperature and high-pressure environment, the quartz glass 4 has the functions of sealing, heat insulation, and preventing pollutants from contacting the filter. Sealing gaskets 5 are arranged on both sides of the quartz glass 4, and the sealing gaskets 5 are preferably high-temperature-resistant sealing gaskets. Since pollutants such as soot are usually generated in the combustion environment, if the pollutants directly contact the filter 6, it will damage the filter 6.

[0040] Inside the PMT connection end 3, a fourth hole 301, a fifth hole 302, and a sixth hole 303 with gradually decreasing apertures are arranged from left to right. The right end of the flange pressing block 2 extends into the fourth hole 301, and there is an accommodation space between the right end of the flange pressing block 2 and the bottom wall of the fourth hole 301. The filter 6 is arranged in the accommodation space, and sealing gaskets 5 are arranged on both sides of the filter 6.

[0041] Because the light generated by combustion is a free group composed of various free radicals, when performing flame detection, it is usually necessary to select a certain free radical for quantitative analysis. For example, when it is necessary to detect the excited state OH, a filter with a wavelength of 310nm can be installed to filter light in other bands. The filter 6 can be adjusted according to the species change of the excited state free radical to be detected. Due to the different thicknesses of the filters, it is not convenient to install them. Sealing gaskets 5 are arranged on the left and right sides of the filter 6 to adjust and fix the filter 6.

[0042] The right outer wall of the PMT connection end 3 is provided with a connecting thread, and it is connected to the outer shell of the photomultiplier tube through the connecting thread. The photomultiplier tube is a prior art, and its specific structure will not be elaborated here. In addition, the aperture of the sixth hole needs to adapt to the best light contact area of the photomultiplier tube.

[0043] Using the gas turbine combustion flame detection device based on the self-luminescence of excited state free radicals provided by the present utility model for experimental testing, the installed filter is 310nm with a bandpass of 10nm. The finally obtained waveform is simple and the noise signal is small, and the start and end of ignition can be accurately identified. While directly using the photomultiplier tube (PMT) to measure the combustion diagnosis result of the ignition delay period of ammonia, the waveform is chaotic and the start and end of ignition cannot be accurately identified.

[0044] The above specific embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the scope of the technical solutions of the present invention, and all of them should be covered by the scope of the claims of the present invention.

Claims

1. A gas turbine combustion flame detection device based on excited state free radical self-luminescence, characterized in that, It includes a signal filtering device and a photomultiplier tube. The signal filtering device includes a flame detection end, a flange pressing block, and a PMT connection end. Through holes that are connected are provided inside the flame detection end, the flange pressing block, and the PMT connection end for the passage and filtering of optical signals. The flame detection end is internally connected to the device to be detected, and there is a flame inside the device to be detected. The flame detection end is used to receive the light emitted by the flame. A filter is provided between the flange pressing block and the PMT connection end. The PMT connection end is connected to the photomultiplier tube.

2. The gas turbine combustion flame detection device based on the self-luminescence of excited-state free radicals according to claim 1, characterized in that, From left to right, the flame detection end includes a first boss, a second boss, and a connecting flange with diameters increasing in sequence. The first boss extends deep into the device to be detected. The connecting flange is connected to the flange pressing block.

3. The gas turbine combustion flame detection device based on the self-luminescence of excited-state free radicals according to claim 2, characterized in that, The length of the first boss is the same as the wall thickness of the device to be detected.

4. The gas turbine combustion flame detection device based on excited state free radical self-luminescence according to claim 2, wherein, A light spot hole with a diameter of 1 mm is provided on the left end face of the first boss.

5. The gas turbine combustion flame detection device based on excited state free radical self-luminescence according to claim 4, characterized in that, The through hole inside the flange pressing block has the same diameter as the light spot hole.

6. The gas turbine combustion flame detection device based on excited state free radical self-luminescence according to claim 2, characterized in that, Threads are provided on the outer surface of the second boss.

7. The gas turbine combustion flame detection device based on the self-luminescence of excited-state free radicals according to claim 2, characterized in that, A cooling device is provided outside the second boss.

8. The gas turbine combustion flame detection device based on excited state free radical self-luminescence according to claim 2, characterized in that, From left to right inside the flame detection end, a first hole, a second hole, and a third hole with diameters increasing in sequence are provided. The first hole is a light hole. The left end of the flange pressing block extends deep into the third hole.

9. The gas turbine combustion flame detection device based on excited state free radical self-luminescence according to claim 8, characterized in that, There is a receiving space between the left end of the flange pressing block and the bottom wall of the third hole. Quartz glass is provided in the receiving space, and gaskets are provided on both sides of the quartz glass.

10. The gas turbine combustion flame detection device based on the self-luminescence of excited-state free radicals according to claim 1, characterized in that, From left to right inside the PMT connection end, a fourth hole, a fifth hole, and a sixth hole with diameters decreasing in sequence are provided. The right end of the flange pressing block extends deep into the fourth hole, and there is a receiving space between the right end of the flange pressing block and the bottom wall of the fourth hole. The filter is provided in the receiving space, and gaskets are provided on both sides of the filter.

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