Length-adjustable infrared probe for remote measurement of combustion system

Abstract

The invention provides a length-adjustable infrared probe for remote measurement of a combustion system, which belongs to the field of infrared measurement and comprises an infrared thermometer, a telescopic lens cone and a telescopic cooling sleeve, one end of the telescopic lens cone is connected with the infrared thermometer, and the other end of the telescopic lens cone is connected with the telescopic cooling sleeve. Radiation signals of a to-be-measured target can be converged to a lens of the infrared thermometer through the telescopic lens cone, a window piece is arranged at one end, far away from the infrared thermometer, of the telescopic lens cone, the distance between the window piece of the telescopic lens cone and the lens of the infrared thermometer can be adjusted, and the telescopic lens cone is completely located in the telescopic cooling sleeve. The telescopic cooling sleeve is provided with a cooling working medium inlet, a cooling cavity and a cooling working medium outlet which are communicated, and a cooling working medium discharged from the cooling working medium outlet can form an air film layer outside the window of the telescopic lens cone. The cooling sleeve can provide a suitable working environment for the telescopic lens cone and the infrared thermometer in a high-temperature, high-pressure and dusty severe environment, and the length of the cooling sleeve and the length of the telescopic lens cone can be adjusted.

Description

Technical Field

[0001] The invention belongs to the technical field of infrared measurement, and in particular relates to an infrared probe with adjustable length for long-distance measurement of a combustion system. Background Art

[0002] Key components in large combustion systems such as power plant boilers and gas turbines operate in complex and extreme environments for a long time, and will be damaged by the erosion of high temperature pulsation of turbulent flames, affecting the safe and stable operation of the entire equipment. Therefore, the surface temperature of key components at the hot end of the combustion system is one of the important indicators of concern. In actual work, due to the constraints of working environments such as temperature, pressure, dust, and measurement distance, the surface temperature monitoring technology of key components in large combustion systems has certain difficulties.

[0003] Traditional contact temperature measurement methods are no longer suitable for such complex working conditions. The highly adaptable non-contact infrared temperature measurement method, especially when measuring at long distances, has multiple interference signals in the propagation path of the radiation signal, which increases the difficulty of infrared temperature measurement instruments to extract useful signals. In addition, the infrared measurement device needs to have high sensitivity at room temperature or even lower temperatures, so it needs to be installed far away from the combustion system. This free installation method increases the complexity and uncertainty of the entire system.

[0004] Therefore, there is an urgent need for an integrated high-temperature resistant cooling probe with adjustable distance that can be assembled with the combustion system. According to the internal fire environment of the combustion system, an installable cooling-type adjustable-length probe is introduced as a directional transmission path for the radiation signal. Through a simple optical system, the light recording and focusing of the measurement space process can be realized to meet the needs of long-distance precise positioning and telemetry while withstanding the erosion of the high-temperature environment. Summary of the invention

[0005] In view of this, in order to solve the problem of multiple interference signals in the long-distance measurement of the surface temperature of key components of the hot end in complex and extreme environments in large combustion systems, and the problem that high-temperature-resistant infrared temperature measuring devices need to be installed freely, which increases the complexity and uncertainty of the system, the present invention proposes a length-adjustable infrared probe for long-distance measurement of combustion systems.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] An infrared probe with adjustable length for long-distance measurement of a combustion system, comprising:

[0008] Infrared thermometer;

[0009] A telescopic lens barrel, one end of which is connected to the infrared thermometer, the radiation signal of the target to be measured can be converged to the lens of the infrared thermometer through the telescopic lens barrel, a window is provided at one end of the telescopic lens barrel away from the infrared thermometer, and the distance between the window of the telescopic lens barrel and the lens of the infrared thermometer can be adjusted;

[0010] A retractable cooling sleeve, the retractable lens barrel is entirely located in the retractable cooling sleeve, one end of the retractable cooling sleeve can be connected to the infrared thermometer, the retractable cooling sleeve is provided with a cooling cavity, the end of the retractable cooling sleeve close to the infrared thermometer is provided with a cooling medium inlet, the end of the retractable cooling sleeve away from the infrared thermometer is provided with multiple cooling medium outlets at intervals, the cooling medium inlet, the cooling cavity and the cooling medium outlet are sequentially connected, and the cooling medium discharged from the cooling medium outlet can form an air film layer outside the window of the retractable lens barrel.

[0011] As a preferred solution of the above-mentioned length-adjustable infrared probe for long-distance measurement of combustion systems, the retractable lens barrel includes a first lens barrel, a second lens barrel and a third lens barrel, one end of the first lens barrel is provided with the window piece, and the other end is provided with a first internal thread, one end of the second lens barrel is provided with a first external thread, and the other end is provided with a second internal thread, one end of the third lens barrel can be connected to the infrared thermometer, and the other end is provided with a second external thread, the first internal thread is screwed with the first external thread, and the second internal thread is screwed with the second external thread, a focusing piece is fixed in the first lens barrel, a collimating piece is fixed in the second lens barrel, and a meniscus lens is fixed in the third lens barrel.

[0012] As a preferred solution of the above-mentioned length-adjustable infrared probe for long-distance measurement of combustion systems, a plurality of first scale lines are provided on the first external thread of the second lens barrel, and the plurality of first scale lines are arranged at intervals along the axial direction; a plurality of second scale lines are provided on the second external thread of the third lens barrel, and the plurality of second scale lines are arranged at intervals along the axial direction.

[0013] As a preferred solution of the above-mentioned length-adjustable infrared probe for long-distance measurement of the combustion system, one end of the third lens barrel is provided with a connecting hole, and the lens of the infrared thermometer is clamped in the connecting hole.

[0014] As a preferred solution of the above-mentioned length-adjustable infrared probe for long-distance measurement of the combustion system, the retractable cooling sleeve includes a front cooling sleeve and a rear cooling sleeve, one end of the rear cooling sleeve can be connected to the infrared thermometer, and the other end is provided with a third internal thread, and the front cooling sleeve is provided with a third external thread, and the third external thread is screwed to the third internal thread.

[0015] As a preferred solution of the above-mentioned length-adjustable infrared probe for long-distance measurement of combustion systems, a plurality of third scale lines are provided on the third external thread, and the plurality of third scale lines are spaced apart in the axial direction.

[0016] As a preferred solution of the above-mentioned length-adjustable infrared probe for long-distance measurement of the combustion system, one end of the rear-stage cooling sleeve is connected to the infrared thermometer via a fixing pin.

[0017] As a preferred solution of the above-mentioned length-adjustable infrared probe for long-distance measurement of the combustion system, the front-section cooling sleeve includes a first-section sleeve and a second-section sleeve, one end of the first-section sleeve is connected to the rear-section cooling sleeve, and the other end is fixedly connected to the second-section sleeve, and the second-section sleeve is inclined inwardly relative to the first-section sleeve.

[0018] As a preferred solution of the above-mentioned length-adjustable infrared probe for long-distance measurement of the combustion system, it also includes a fixing ring, which is located between the front cooling sleeve and the retractable cooling sleeve, and the two ends of the fixing ring are respectively abutted against the front cooling sleeve and the retractable cooling sleeve.

[0019] As a preferred solution of the above-mentioned length-adjustable infrared probe for long-distance measurement of a combustion system, the fixing ring is made of rubber material.

[0020] Compared with the prior art, the beneficial effects of the infrared probe with adjustable length for long-distance measurement of a combustion system provided by the present invention are:

[0021] The invention provides an infrared probe with adjustable length for long-distance measurement of a combustion system. The infrared probe with adjustable length for long-distance measurement of a combustion system is applied to the field of long-distance infrared temperature measurement of a large combustion system. The entire probe and the combustion system are fixedly assembled to each other by punching. The radiation signal of the target to be measured can be converged on the lens of the infrared thermometer through a retractable lens barrel. Combined with a simple optical path through the long-distance probe, the interference of useless signals in the propagation path of the measurement signal is reduced, and the long-distance precise positioning and telemetry requirements of key hot end components in the large combustion system are met; the distance between the window of the retractable lens barrel and the lens of the infrared thermometer can be adjusted, so as to meet the micro-distance adjustment requirements under the condition of fixed installation of the probe; the retractable lens The barrel is entirely located in a retractable cooling sleeve, and a cooling medium flows in the cooling cavity of the cooling sleeve. The cooling sleeve can withstand high-temperature erosion of about 1000°C in a harsh working environment, and provide a suitable working environment for the retractable lens barrel and the infrared thermometer. At the same time, the cooling medium is discharged from the cooling medium outlet after passing through the cooling cavity. The discharged cooling medium can form a thin air film layer outside the window of the retractable lens barrel, and the air film layer has a further protective effect on the window, and also has the function of preventing dust pollution. Therefore, the cooling sleeve can provide a suitable working environment for the retractable lens barrel and the infrared thermometer in a harsh environment of high temperature, high pressure and much dust, thereby ensuring the safe and stable operation of the equipment. At the same time, the length of the cooling sleeve can be adjusted accordingly according to the required measuring distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0023] Figure 1 It is a schematic diagram of the structure of an infrared probe with adjustable length for long-distance measurement of a combustion system provided by a specific embodiment of the present invention;

[0024] Figure 2 It is a cross-sectional view of a rear cooling sleeve of a length-adjustable infrared probe for long-distance measurement of a combustion system provided by a specific embodiment of the present invention;

[0025] Figure 3 It is a structural schematic diagram of a first lens barrel of an infrared probe with adjustable length for long-distance measurement of a combustion system provided by a specific embodiment of the present invention;

[0026] Figure 4 It is a structural schematic diagram of a second lens barrel of an infrared probe with adjustable length for long-distance measurement of a combustion system provided by a specific embodiment of the present invention;

[0027] Figure 5 It is a structural schematic diagram of a third lens barrel of an infrared probe with adjustable length for long-distance measurement of a combustion system provided by a specific embodiment of the present invention;

[0028] Figure 6 It is a structural schematic diagram of a window piece of an infrared probe with adjustable length for long-distance measurement of a combustion system provided by a specific embodiment of the present invention;

[0029] Figure 7 It is a structural schematic diagram of a condenser of an infrared probe with adjustable length for long-distance measurement of a combustion system provided by a specific embodiment of the present invention;

[0030] Figure 8 It is a structural schematic diagram of a collimator of an infrared probe with adjustable length for long-distance measurement of a combustion system provided by a specific embodiment of the present invention;

[0031] Fig. 9 It is a structural schematic diagram of a meniscus lens of an infrared probe with adjustable length for long-distance measurement of a combustion system provided by a specific embodiment of the present invention;

[0032] Fig.10 It is a schematic structural diagram of an infrared probe with adjustable length for long-distance measurement of a combustion system provided by a specific embodiment of the present invention when L7 is at a maximum;

[0033] Fig.111 is a schematic structural diagram of an infrared probe with adjustable length for long-distance measurement of a combustion system provided by a specific embodiment of the present invention when L7 is minimum;

[0034] Fig.12 It is a schematic diagram of the transfer function (MIF) at infinity when L7=1010 mm in an infrared probe with adjustable length for long-distance measurement of a combustion system provided by a specific embodiment of the present invention;

[0035] Fig.13 It is a result diagram of the light spot (RMS) of the image plane of the infrared probe with adjustable length for long-distance measurement of the combustion system at five optional measurement distances provided by the specific embodiment of the present invention.

[0036] In the figure:

[0037] 11. Front cooling sleeve; 12. Rear cooling sleeve; 13. Cooling medium inlet; 14. Cooling medium outlet; 15. Cooling cavity;

[0038] 21. first lens barrel; 22. second lens barrel; 23. third lens barrel;

[0039] 31. Window; 32. Condenser; 33. Collimator; 34. Meniscus lens;

[0040] 4. Target to be measured;

[0041] 5. Infrared thermometer; 51. Lens;

[0042] 6. Fixed ring;

[0043] 7. Fixing pin. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely explain the technical solutions in the embodiments of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0045] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0047] In the description of this embodiment, the terms "upper", "lower", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0048] See also Figure 1-13 The present embodiment is described. The present invention provides a length-adjustable infrared probe for long-distance measurement of a combustion system. The length-adjustable infrared probe for long-distance measurement of a combustion system comprises a retractable lens barrel, a retractable cooling sleeve and an infrared thermometer 5. One end of the retractable lens barrel is connected to the infrared thermometer 5. The radiation signal of the target 4 to be measured can be converged on the lens 51 of the infrared thermometer 5 through the retractable lens barrel. The end of the retractable lens barrel away from the infrared thermometer 5 is provided with a window 31. The distance between the window 31 of the retractable lens barrel and the lens 51 of the infrared thermometer 5 is 1 / 40mm. The telescopic lens barrel is entirely located in the telescopic cooling sleeve, one end of the telescopic cooling sleeve can be connected to the infrared thermometer 5, the telescopic cooling sleeve is provided with a cooling cavity 15, the end of the telescopic cooling sleeve close to the infrared thermometer 5 is provided with a cooling medium inlet 13, and the end of the telescopic cooling sleeve away from the infrared thermometer 5 is provided with a plurality of cooling medium outlets 14 at intervals, the cooling medium inlet 13, the cooling cavity 15 and the cooling medium outlet 14 are sequentially connected, and the cooling medium discharged from the cooling medium outlet 14 can form an air film layer outside the window 31 of the telescopic lens barrel.

[0049] The infrared probe with adjustable length for long-distance measurement of the combustion system is applied to the field of long-distance infrared temperature measurement of large combustion systems. The entire probe and the combustion system are fixedly assembled to each other by punching. The radiation signal of the target 4 to be measured can be converged to the lens 51 of the infrared thermometer 5 through the retractable lens barrel. Combined with the simple optical path through the long-distance probe, the interference of useless signals in the propagation path of the measurement signal is reduced, and the long-distance precise positioning and telemetry requirements of key hot end components in the large combustion system are met; the distance between the window 31 of the retractable lens barrel and the lens 51 of the infrared thermometer 5 can be adjusted to meet the micro-distance adjustment requirements under the condition of fixed installation of the probe; the retractable lens barrel is entirely located in the retractable cooling sleeve, and the cooling sleeve There is a cooling medium flowing in the cooling cavity 15 of the barrel. The cooling sleeve can withstand high temperature erosion of about 1000°C in a harsh working environment, and provide a suitable working environment for the telescopic barrel and the infrared thermometer 5. At the same time, the cooling medium is discharged from the cooling medium outlet 14 after passing through the cooling cavity 15. The discharged cooling medium can form a thin air film layer outside the window 31 of the telescopic barrel. The air film layer has a further protective effect on the window 31 and also has the function of preventing dust pollution. Therefore, the cooling sleeve can provide a suitable working environment for the telescopic barrel and the infrared thermometer 5 in a harsh environment of high temperature, high pressure and dust, thereby ensuring the safe and stable operation of the equipment. At the same time, the length of the cooling sleeve can be adjusted accordingly according to the required measuring distance.

[0050] Optionally, the retractable lens barrel includes a first lens barrel 21, a second lens barrel 22 and a third lens barrel 23, one end of the first lens barrel 21 is provided with the window 31, and the other end is provided with a first internal thread, one end of the second lens barrel 22 is provided with a first external thread, and the other end is provided with a second internal thread, one end of the third lens barrel 23 can be connected to the infrared thermometer 5, and the other end is provided with a second external thread, the first internal thread is screwed with the first external thread, and the second internal thread is screwed with the second external thread, a focusing piece 32 is fixedly provided in the first lens barrel 21, a collimating piece 33 is fixedly provided in the second lens barrel 22, and a meniscus lens 34 is fixedly provided in the third lens barrel 23.

[0051] The radiation signal of the target 4 to be measured passes through the window 31, the focusing plate 32, the collimating plate 33 and the meniscus lens 34 in sequence, and finally converges on the lens 51 of the infrared measuring instrument.

[0052] The window 31 is a sapphire plane mirror, which has a high transmittance to mid-infrared rays in the band of 2 to 5 μm, high hardness, strong adaptability in the harsh environment of the combustion system, and plays a role in protecting subsequent lenses. The focusing piece 32 is a germanium-zinc sulfide double-glued meniscus lens 34 with a convex surface facing the direction of the object to be measured, which has a high transmittance to mid-infrared rays in the band of 2 to 5 μm, and plays a role in converging light and extending the light path; the collimating piece 33 is a germanium-zinc sulfide double-glued meniscus lens with a convex surface facing the direction of the target to be measured 4, which has a high transmittance to mid-infrared rays in the band of 2 to 5 μm, and plays a role in collimating light and extending the light path; the meniscus lens 34 is a sapphire meniscus lens with a convex surface facing the direction of the target to be measured 4, which has a high transmittance to mid-infrared rays in the band of 2 to 5 μm, and plays a role in converging light to the lens of the infrared measuring instrument.

[0053] Specific parameters of the window 31 , the focusing sheet 32 ​​, the collimating sheet 33 , and the meniscus lens 34 are shown in Table 1.

[0054] Table 1 Lens specific parameters

[0055]

[0056] The first lens barrel 21 is used to fix the window 31 and the condenser 32. The window 31 is assembled at the left opening of the first lens barrel 21. The front edge of the window 31 is at a distance L1 from the target 4 to be measured, and the rear edge of the window 31 is at a distance L2 from the front edge of the condenser 32.

[0057] The second lens barrel 22 is used to fix the collimating sheet 33 , and the front edge of the collimating sheet 33 is spaced apart from the rear edge of the focusing sheet 32 ​​mounted on the first lens barrel 21 by a distance L3 .

[0058] The third lens barrel 23 is used to fix the meniscus lens 34 . The front edge of the meniscus lens 34 is L4 away from the rear edge of the collimating plate 33 mounted on the second lens barrel 22 . The rear edge of the meniscus lens 34 is L5 away from the front edge of the lens 51 of the infrared thermometer 5 .

[0059] Among them, L1, L2 and L5 are fixed lengths, L1 = 550mm, L2 = 300mm, L5 = 20mm. The first lens barrel 21 and the second lens barrel 22 are assembled by the first internal thread and the first external thread, and the distance between the collimating plate 33 and the focusing plate 32 can be adjusted by the first internal thread and the first external thread; the second lens barrel 22 and the third lens barrel 23 are assembled by the second internal thread and the second external thread, and the distance between the meniscus lens 34 and the collimating plate 33 can be adjusted by the second internal thread and the second external thread. The distance L7 from the target 4 to the lens of the infrared thermometer 5 has five options: 970mm, 980mm, 990mm, 1000mm, and 1010mm.

[0060] Optionally, a plurality of first scale lines are provided on the first external thread of the second lens barrel 22, and the plurality of first scale lines are spaced apart along the axial direction; a plurality of second scale lines are provided on the second external thread of the third lens barrel 23, and the plurality of second scale lines are spaced apart along the axial direction. The length of the telescopic lens barrel can be adjusted simply by rotating the internal and external threads to the corresponding scale lines.

[0061] In this embodiment, the first external thread of the second lens barrel 22 has five first scale lines from left to right, respectively representing five length options of L3: 85mm, 80mm, 75mm, 65mm, and 60mm; the second external thread of the third lens barrel 23 has four second scale lines from left to right, respectively representing four length options of L4: 22mm, 27mm, 32mm, and 37mm.

[0062] In this embodiment, Figure 3 As shown, the first lens barrel 21 is a round stainless steel tube of Φ20 with a total length of 353 mm. A hole with a diameter of 12.5 mm is bored at the left end for assembling the window sheet 31 , and a M16×1 internal thread with a length of 45 mm is machined at the right end as the first internal thread.

[0063] like Figure 4 As shown, the second lens barrel 22 is made of a round stainless steel tube with a specification of Φ18×2 and a total length of 71mm. The left end is machined with a 45mm long M16×1 external thread as the first external thread, and the other end is machined with a 20mm long M14×1 internal thread as the second internal thread.

[0064] like Figure 5 As shown, the third lens barrel 23 is made of a round stainless steel tube with a specification of Φ14×2 and a total length of 42mm. A 20mm long M14×1 external thread is turned on the left end as the second external thread, and a Φ12 blind hole with a depth of 2mm is opened on the right end as a connecting hole for assembling the lens 51 of the infrared measuring instrument.

[0065] Optionally, a connection hole is provided at one end of the third lens barrel 23, and the lens 51 of the infrared thermometer 5 is snap-fitted into the connection hole.

[0066] Optionally, the retractable cooling sleeve includes a front cooling sleeve 11 and a rear cooling sleeve 12, one end of the rear cooling sleeve 12 can be connected to the infrared thermometer 5, and the other end is provided with a third internal thread, and the front cooling sleeve 11 is provided with a third external thread, and the third external thread is screwed with the third internal thread. The front cooling sleeve 11 is provided with a M8×5 third external thread with a length of 100 mm, and the rear cooling sleeve 12 is provided with a M8×5 third internal thread with a length of 100 mm, and a Φ27×1 round stainless steel pipe is welded as a cooling medium inlet 13.

[0067] Optionally, the third external thread is provided with a plurality of third scale lines, which are spaced apart in the axial direction. The third external thread is marked with five third scale lines, which respectively represent the distance L6 from the front end of the front cooling sleeve 11 to the front edge of the lens 51 of the infrared measuring instrument, which has five options of 446mm, 456mm, 466mm, 476mm, and 486mm, and the distance L6 is selected according to L7.

[0068] The length of the retractable cooling sleeve can be adjusted by the third internal thread and the third external thread, so as to realize the adjustability of the distance L6 between the front edge of the front cooling sleeve 11 and the front edge of the lens 51 of the infrared measuring instrument and the distance L7 between the target 4 to be measured and the lens 51 of the infrared measuring instrument. According to the measurement requirements, the adjustable range of L6 is 466±20mm, and the adjustable range of L7 is 990±20mm. The specific adjustment selection method is shown in Table 2, which avoids the problem of repeated disassembly and assembly between the probe device and the combustion system, and between the probe device and the infrared measuring instrument.

[0069] Table 2 Probe length adjustable selection method

[0070]

[0071] The front cooling sleeve 11 and the rear cooling sleeve 12 are connected by the third internal thread and the third external thread to form a whole retractable cooling sleeve, and its length can be adjusted according to the selected L6 and L7. The retractable cooling sleeve can withstand the heat radiation from the high-temperature flue gas and flame of about 1000°C, and provide a suitable working environment of 80-100°C for the optical elements in the probe. The cooling medium discharged from the cooling medium outlet 14 can perform air film cooling protection on the window 31 assembled at the left end opening of the first lens barrel 21, and play a role in soot blowing and dust prevention.

[0072] Optionally, the front cooling sleeve 11 includes a first sleeve and a second sleeve, one end of the first sleeve is connected to the rear cooling sleeve 12, and the other end is fixedly connected to the second sleeve, and the second sleeve is tilted inwardly relative to the first sleeve, so that the gas discharged from the cooling medium outlet 14 can be gathered in front of the window 31.

[0073] Optionally, one end of the rear cooling sleeve 12 is connected to the infrared thermometer 5 through a fixing pin 7. The rear cooling sleeve 12 is assembled with the infrared measuring instrument housing through the fixing pin 7, and four positioning holes are bored at intervals of 90 degrees at the bottom of the rear cooling sleeve 12 for installing the fixing pin 7.

[0074] Optionally, the infrared probe with adjustable length for long-distance measurement of the combustion system further includes a fixing ring 6, which is located between the front cooling sleeve 11 and the retractable cooling sleeve, and the two ends of the fixing ring 6 are respectively in contact with the front cooling sleeve 11 and the retractable cooling sleeve. The front cooling sleeve 11 and the first lens barrel 21 are assembled through the fixing ring 6, and there are 6 fixing rings 6, which are installed in sequence at intervals of 50 mm to support the retractable lens barrel.

[0075] Optionally, the fixing ring 6 is made of rubber material.

[0076] like Fig.10 As shown, at this time, the measured distance L7 is the maximum value of 1010mm. According to the parameters in Table 2, it is necessary to adjust the length of L3 to 85mm and the length of L4 to 37mm respectively; rotate the internal and external threads between the first lens barrel 21 and the second lens barrel 22 to the first first scale line at the first external thread of the second lens barrel 22 (the first first scale line from left to right); and rotate the internal and external threads between the second lens barrel 22 and the third lens barrel 23 to the first second scale line at the second external thread of the third lens barrel 23 (the first second scale line from left to right).

[0077] like Fig.11 As shown, at this time, the measured distance L7 is the minimum value of 970mm. According to the parameters in Table 2, it is known that the length of L3 must be adjusted to 60mm and the length of L4 must be adjusted to 22mm respectively; the internal and external threads between the first lens barrel 21 and the second lens barrel 22 are rotated to the fifth first scale line (the fifth first scale line from left to right) at the first external thread of the second lens barrel 22; and the internal and external threads between the second lens barrel 22 and the third lens barrel 23 are rotated to the fourth second scale line (the fourth second scale line from left to right) at the second external thread of the third lens barrel 23;

[0078] like Fig.12 As shown, this is the transfer function (MIF) diagram of the entire optical system of the probe at infinity when the maximum measurement distance L7 = 1010 mm;

[0079] like Fig.13 As shown in the figure, the image plane spot (RMS) result diagram of the entire probe optical system at five optional measurement distances with fine distance adjustment.

[0080] Obviously, the embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. According to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. It is not necessary and impossible to exhaustively list all the embodiments here.

Claims

1. An infrared probe with adjustable length for long-distance measurement of a combustion system, characterized in that: include: Infrared thermometer (5); A telescopic lens barrel, one end of which is connected to an infrared thermometer (5), and a radiation signal of a target to be measured (4) can be converged onto a lens (51) of the infrared thermometer (5) through the telescopic lens barrel, and a window (31) is provided at one end of the telescopic lens barrel away from the infrared thermometer (5), and the distance between the window (31) of the telescopic lens barrel and the lens (51) of the infrared thermometer (5) can be adjusted; A retractable cooling sleeve, wherein the retractable lens barrel is entirely located within the retractable cooling sleeve, one end of the retractable cooling sleeve can be connected to an infrared thermometer (5), the retractable cooling sleeve is provided with a cooling cavity (15), one end of the retractable cooling sleeve close to the infrared thermometer (5) is provided with a cooling medium inlet (13), and one end of the retractable cooling sleeve far from the infrared thermometer (5) is provided with a plurality of cooling medium outlets (14) at intervals, the cooling medium inlet (13), the cooling cavity (15) and the cooling medium outlet (14) are sequentially connected, and the cooling medium discharged from the cooling medium outlet (14) can form an air film layer outside the window sheet (31) of the retractable lens barrel.

2. The length-adjustable infrared probe for long-distance measurement of a combustion system according to claim 1, characterized in that: The telescopic lens barrel comprises a first lens barrel (21), a second lens barrel (22) and a third lens barrel (23); one end of the first lens barrel (21) is provided with the window sheet (31), and the other end is provided with a first internal thread; one end of the second lens barrel (22) is provided with a first external thread, and the other end is provided with a second internal thread; one end of the third lens barrel (23) can be connected to the infrared thermometer (5), and the other end is provided with a second external thread; the first internal thread is screwed to the first external thread, and the second internal thread is screwed to the second external thread; a condenser sheet (32) is fixedly provided in the first lens barrel (21), a collimator sheet (33) is fixedly provided in the second lens barrel (22), and a meniscus lens (34) is fixedly provided in the third lens barrel (23).

3. The length-adjustable infrared probe for long-distance measurement of a combustion system according to claim 2, characterized in that: The first external thread of the second lens barrel (22) is provided with a plurality of first scale lines, which are spaced apart in the axial direction; the second external thread of the third lens barrel (23) is provided with a plurality of second scale lines, which are spaced apart in the axial direction.

4. The length-adjustable infrared probe for long-distance measurement of a combustion system according to claim 2, characterized in that: One end of the third lens barrel (23) is provided with a connection hole, and the lens (51) of the infrared thermometer (5) is snap-connected to the connection hole.

5. The length-adjustable infrared probe for long-distance measurement of a combustion system according to claim 1, characterized in that: The retractable cooling sleeve comprises a front cooling sleeve (11) and a rear cooling sleeve (12); one end of the rear cooling sleeve (12) can be connected to the infrared thermometer (5), and the other end is provided with a third internal thread; the front cooling sleeve (11) is provided with a third external thread, and the third external thread is screwed to the third internal thread.

6. The infrared probe with adjustable length for long-distance measurement of combustion system according to claim 5, characterized in that: The third external thread is provided with a plurality of third scale lines, and the plurality of third scale lines are arranged at intervals along the axial direction.

7. The length-adjustable infrared probe for long-distance measurement of a combustion system according to claim 5, characterized in that: One end of the rear cooling sleeve (12) is connected to the infrared thermometer (5) via a fixing pin (7).

8. The length-adjustable infrared probe for long-distance measurement of a combustion system according to claim 5, characterized in that: The front section cooling sleeve (11) comprises a first section sleeve and a second section sleeve, one end of the first section sleeve is connected to the rear section cooling sleeve (12), and the other end is fixedly connected to the second section sleeve, and the second section sleeve is arranged to be inclined inwardly relative to the first section sleeve.

9. The length-adjustable infrared probe for long-distance measurement of a combustion system according to claim 5, characterized in that: It also comprises a fixing ring (6), which is located between the front cooling sleeve (11) and the telescopic cooling sleeve, and the two ends of the fixing ring (6) are respectively in contact with the front cooling sleeve (11) and the telescopic cooling sleeve.

10. The length-adjustable infrared probe for long-distance measurement of a combustion system according to claim 9, characterized in that: The fixing ring (6) is made of rubber material.

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