An intelligent detection system for nitrogen oxides and its usage method

Abstract

The present invention relates to the technical field related to the detection of nitrogen oxides. The present invention provides an intelligent detection system for nitrogen oxides and its usage method, which includes a flue tube and upper and lower ring covers fixedly arranged at the upper and lower ends of the flue tube. A sampling rod extending longitudinally is arranged inside the flue tube. The upper and lower ends of the sampling rod are respectively connected to the upper and lower ring covers. The sampling rod includes an outer tube and a middle tube. The outer tube is sleeved outside the middle tube, and a cooling ring cavity is formed between the outer tube and the middle tube. Installation slots are opened on the outer tube, and a sampling tube is inserted into the installation slots. This device is provided with an exhalation mode, which uses a clean gas to replace the residual flue gas in the sampling tube and the detection cavity. In order to improve the effectiveness of exhalation, during each upward movement of the piston cylinder for exhalation, the clean gas in the exhalation cavity is ejected downward through a one-way jet port, and the waste gas in the detection cavity is replaced by the clean gas, so as to reduce the error caused by the residual nitrogen oxides to the next measurement.

Description

Technical Field

[0001] The present invention belongs to the technical field related to the detection of nitrogen oxides. More specifically, it particularly relates to an intelligent detection system for nitrogen oxides and its usage method. Background Art

[0002] Nitrogen oxides (NOx) are one of the main components of air pollution, mainly sourced from industrial production, vehicle exhaust, and combustion processes. NOx is not only harmful to human health but also causes environmental problems such as acid rain and photochemical smog. Therefore, the accurate detection and monitoring of NOx have become an important link in environmental protection and industrial production.

[0003] The existing technologies also have the following technical problems:

[0004] Traditional NOx detection systems usually adopt a decentralized design and use a multi-point measurement method to improve data reliability. The distribution positions of sampling points occupy a large space in the air, making installation inconvenient. Each detection module operates independently, resulting in a large system volume, complex installation, and difficulty in achieving synchronous detection at multiple positions. In addition, when the traditional detection system works in a high-temperature flue gas environment, the sensor is easily affected by high temperature, leading to inaccurate measurement data and even shortening the service life of the sensor. At the same time, the problem of flue gas residue will also affect the accuracy of subsequent measurements. Especially in continuous monitoring scenarios, the residual NOx will cause the accumulation of measurement errors and further reduce the reliability of data.

[0005] To solve the above problems, some integrated NOx detection systems have been proposed in the existing technologies, but these systems often have limitations in terms of volume reduction and function integration. Especially in aspects such as the cooling treatment of high-temperature flue gas, sensor protection, and system self-cleaning, there is still room for improvement. In addition, the existing detection systems lack effective self-cleaning and waste gas removal mechanisms, resulting in the sensor being exposed to a harsh environment for a long time, affecting its service life and measurement accuracy.

[0006] Therefore, there is an urgent need for a new type of intelligent detection system for nitrogen oxides, which can achieve system integration and miniaturization while ensuring detection accuracy, and has efficient cooling, self-cleaning, and waste gas removal functions to extend the service life of the sensor and improve the accuracy and reliability of measurement data. Summary of the Invention

[0007] The present invention provides an intelligent detection system for nitrogen oxides and its usage method to overcome the above defects in the existing technologies.

[0008] The objectives and effects of an intelligent detection system for nitrogen oxides and its usage method of the present invention are achieved by the following specific technical means:

[0009] An intelligent detection system for nitrogen oxides, comprising a flue duct cylinder, an upper ring cover and a lower ring cover fixedly arranged at the upper and lower ends of the flue duct cylinder. A sampling rod extending longitudinally is arranged inside the flue duct cylinder. The upper and lower ends of the sampling rod are respectively connected to the upper ring cover and the lower ring cover. The sampling rod comprises an outer cylinder and a middle cylinder. The outer cylinder is sleeved outside the middle cylinder, and a cooling ring cavity is formed between the outer cylinder and the middle cylinder. Installation slots are formed on the outer cylinder, and sampling tubes are inserted into the installation slots. The sampling tubes extend in the cooling ring cavity along the direction tangent to the middle cylinder. Vent holes are formed in the sampling tubes, and a flue gas inlet aligned with the vent holes is formed on the side of the middle cylinder. A partition cylinder is fixedly arranged inside the middle cylinder. A piston cylinder is slidably arranged below the partition cylinder. A detection cavity is formed between the partition cylinder and the piston cylinder. The flue gas inlet is communicated with the detection cavity. An inner cylinder is longitudinally slidably arranged at the axis of the middle cylinder. The inner cylinder is fixedly connected to the piston cylinder. A nitrogen oxide detection head is installed on the outer wall of the inner cylinder. The nitrogen oxide detection head is located in the detection cavity. An exhalation piston is slidably arranged above the partition cylinder. An exhalation cavity is formed between the exhalation piston and the partition cylinder. A support rod extends downward from the partition cylinder. A traction wire is arranged between the piston cylinder and the exhalation piston. The support rod supports the traction wire downward. A jet device communicating with the detection cavity is further arranged in the exhalation cavity. The exhalation cavity also has a replenishing flow device.

[0010] Further technical solution: A heat preservation layer is arranged on the outer surface of the outer cylinder. A cooling fluid is filled in the cooling ring cavity. A first cover is fixedly arranged at the top of the outer cylinder, and a second cover is fixedly arranged at the bottom of the outer cylinder. A drain pipe communicating with the cooling ring cavity is arranged on the upper end surface of the first cover, and a liquid inlet pipe communicating with the cooling ring cavity is arranged on the lower end surface of the second cover.

[0011] Further technical solution: A plurality of sampling tubes are longitudinally spirally distributed with the flue duct cylinder as the axis. The sampling tubes comprise a first sampling cylinder and a second sampling cylinder. The first sampling cylinder and the second sampling cylinder are connected by an elastic connecting pipe. The elastic connecting pipe has elasticity. A filter cover is detachably arranged at the opening of the first sampling cylinder. A tail plug is fixedly arranged at the tail of the second sampling cylinder. The installation slot and the second sampling cylinder form a sampling cavity. The part of the tail plug extending into the sampling cavity is an inclined surface facing the flue gas inlet.

[0012] Further technical solution: Middle cylinder covers are fixedly arranged at the upper and lower ends of the middle cylinder. Sealing holes are formed in the centers of the middle cylinder covers. The inner cylinder passes through the sealing holes. A motor is fixedly installed on the upper surface of the first cover. A driving gear is fixedly arranged on the shaft of the motor. A driven gear is fixedly arranged at the upper end of the inner cylinder. The driven gear meshes with the driving gear.

[0013] Further technical solution: A cable protection shell is installed at the bottom opening of the inner cylinder. A cable connector is arranged inside the cable protection shell. A detection cable for connecting the nitrogen oxide detection head is arranged inside the inner cylinder. The detection cable extends downward and is connected to the cable connector. A rotating ring is arranged at the lower end of the cable protection shell. An installation plate is fixedly arranged at the lower end of the second cover. A telescopic rod is fixedly installed in the middle of the installation plate. The telescopic shaft of the telescopic rod is rotatably connected to the rotating ring.

[0014] A further technical solution is that the jet device includes a jet tube arranged in the exhalation chamber, the exhalation piston includes an upper ring body at the top, a movable sleeve in the middle and a lower ring body at the bottom, the movable sleeve is on the outside of the inner tube and slides up and down outside the inner tube, the jet tube is sleeved outside the movable sleeve, and the lower end of the jet tube is fixedly connected to the lower ring body, a gas flow channel is formed between the jet tube and the movable sleeve, a limit ring is fixedly arranged on the upper side of the jet tube, a reset spring for pushing the limit ring to reset upward is arranged between the limit ring and the separation tube, a one-way jet port is opened on the lower side wall of the jet tube, and the downward movement of the exhalation piston drives the limit ring to move downward, so that the one-way jet port leaks downward into the detection chamber.

[0015] A further technical solution is that the flow replenishing device includes a one-way opening formed on an upper ring body, an elastic pad is arranged on the lower surface of the upper ring body, the elastic pad elastically covers the lower opening of the one-way opening, the elastic pad can be separated from the lower opening of the one-way opening by a downward force, an air replenishing cylinder is arranged on the upper side of the exhalation piston, the air replenishing cylinder is fixedly connected to the inner cylinder, a switching groove is arranged on the side wall of the air replenishing cylinder, a liquid replenishing port is arranged on the side wall of the middle cylinder, and the rotation of the inner cylinder drives the air replenishing cylinder to rotate synchronously so that the switching groove is aligned or staggered with the liquid replenishing port.

[0016] According to a further technical solution, an air inlet pipe is provided at the top opening of the inner cylinder, a solenoid valve is installed in the air inlet pipe, an air replenishment hole is provided on the side wall of the inner cylinder, an air replenishment cavity is formed between the air replenishment cylinder and the exhalation piston, and the air replenishment hole is located in a position connected to the air replenishment cavity.

[0017] According to a further technical solution, a longitudinal flue gas groove extending longitudinally is provided on the side wall of the piston cylinder, and the inner cylinder drives the piston cylinder to rotate so that the longitudinal flue gas groove is staggered or aligned with the flue gas inlet.

[0018] A further technical solution also includes a processing module and a display module. The cable connector is connected to the processing module via a cable. The processing module receives and processes the signal from the nitrogen oxide detection head, and the processing module sends a display signal to the display module.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] An intelligent detection system for nitrogen oxides of the present invention integrates the nitrogen oxides detection system, reducing its volume. Multiple nitrogen oxides detection heads are longitudinally integrated into the middle cylinder to measure the nitrogen oxides content at multiple points, ensuring the accuracy of data. An outer cylinder is provided outside the middle cylinder, and a cooling ring cavity for the passage of cold liquid is arranged between the outer cylinder and the middle cylinder. A sampling tube is inserted into the side wall of the outer cylinder from outside to inside. The flue gas enters the middle cylinder through the sampling tube. When flowing through the sampling tube, the high-temperature flue gas is cooled by the sampling tube body. Since the extending direction of the sampling tube is tangent to the middle cylinder, the length of the sampling tube in the cooling ring cavity is extended, which is beneficial to further reducing the temperature of the flue gas, enabling the nitrogen oxides detection head to be at an appropriate working temperature, extending the service life of the nitrogen oxides detection head, and maintaining the accuracy of the test data.

[0021] An intelligent detection system for nitrogen oxides of the present invention is provided with an exhalation mode, aiming to replace the residual flue gas in the sampling tube and the detection cavity with clean gas to improve the accuracy of the next measurement. As the piston cylinder reciprocates up and down, the detection cavity realizes two alternating actions of exhalation and inhalation. To improve the effectiveness of exhalation, the device is provided with an exhalation piston, a jet tube, etc. During each upward movement of the piston cylinder for exhalation, the traction wire drives the lower ring body to move downward, causing the jet tube to move downward. The upper ring body moves downward to squeeze the space of the exhalation cavity, increasing the air pressure in the exhalation cavity until the one-way jet orifice on the jet tube leaks downward into the detection cavity. The clean gas in the exhalation cavity is ejected downward through the one-way jet orifice, replacing the waste gas in the detection cavity with clean gas, so as to reduce the error caused by the residual nitrogen oxides in the next measurement. Along with each inhalation sampling of the piston cylinder, there will be an exhalation and exhaust action, so that the detection cavity maintains good cleanliness before each sampling detection, thereby improving the accuracy of the data and reducing the long-term exposure of the nitrogen oxides detection head to the flue gas environment. It will only be normally exposed to the flue gas environment during the test work, thus extending the service life of the nitrogen oxides detection head and improving the precision of the data test.

[0022] An intelligent detection system for nitrogen oxides of the present invention is provided with a self-cleaning mode, which can regularly eject cleaning liquid in the reverse direction into the detection cavity and the sampling tube. When cleaning is required, the switching groove and the liquid replenishing port are aligned. The liquid in the cooling ring cavity enters the air supplement cavity through the liquid replenishing port and the switching groove. There is a part of air remaining in the air supplement cavity. The solenoid valve is opened, and the air pump pumps clean gas into the inner cylinder. The clean gas is supplemented into the air supplement cavity through the air supplement hole to increase the air pressure in the air supplement cavity. When the exhalation piston moves upward, the elastic pad opens the restriction on the one-way opening, and both the liquid and gas in the air supplement cavity can enter the exhalation cavity downward. When the exhalation piston moves downward, the liquid and gas in the exhalation cavity can be sprayed at high speed and circumferentially onto the inner wall of the detection cavity through the one-way jet orifice to achieve the self-cleaning effect. Description of the Drawings

[0023] To more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0024] The present invention will be further described below in conjunction with the drawings and embodiments.

[0025] Figure 1 is the overall structural schematic diagram of the present invention;

[0026] Figure 2 is Figure 1 the longitudinal sectional view of

[0027] Figure 3 is the longitudinal sectional view of the sampling rod in the present invention;

[0028] Figure 4 is the transverse sectional view of the sampling rod in the present invention;

[0029] Figure 5 is the structural schematic diagram of the sampling tube inserted into the cooling ring cavity in the present invention;

[0030] Figure 6 is the partial sectional view of the cylinder in the present invention;

[0031] Figure 7 is the longitudinal sectional view of the cylinder in the present invention;

[0032] Figure 8 is the structural schematic diagram of the exhalation piston in the cylinder of the present invention;

[0033] Figure 9 is the structural schematic diagram of the lower ring cover in the present invention.

[0034] Explanation of reference numerals:

[0035] Flue duct 10, upper ring cover 11, lower ring cover 12, connecting rod 13, sampling rod 14, ventilation channel 15, outer ring 17, first cover 19, driving gear 20, motor 21, drain pipe 22, driven gear 23, solenoid valve 24, outer cylinder 25, middle cylinder 26, inner cylinder 27, thermal insulation layer 28, cooling ring cavity 29, sampling pipe 30, telescopic rod 31, second cover 32, mounting plate 33, liquid inlet pipe 34, rotating ring 35, cable connector 36, cable protection shell 37, liquid supplement port 38, air supplement cylinder 39, air supplement hole 40, partition cylinder 41, exhalation piston 42, exhalation cavity 43, one-way opening 44, elastic pad 45, jet flow cylinder 46, return spring 47, gas flow channel 48, support rod 49, towing wire 50, piston cylinder 51, detection cable 52, nitrogen oxide detection head 53, flue gas inlet 54, flue gas longitudinal groove 55, detection cavity 56, switching groove 58, center ring 59, mounting slot 60, second sampling cylinder 61, first sampling cylinder 62, elastic connecting pipe 63, filter cover 64, sampling cavity 65, tail plug 66, middle cylinder cover 69, upper ring body 71, lower ring body 72, movable sleeve 73, limiting ring 74, air supplement cavity 75. Detailed implementation manners

[0036] The following further describes in detail the implementation manners of the present invention in conjunction with the drawings and embodiments. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0037] In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0038] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connected" 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 directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0039] Refer to the attached Figure 1 - attached Figure 9, An intelligent detection system for nitrogen oxides, including a flue duct 10 and an upper ring cover 11 and a lower ring cover 12 fixedly arranged at the upper and lower ends of the flue duct 10. A sampling rod 14 extending longitudinally is arranged at the axis of the flue duct 10. The upper and lower ends of the sampling rod 14 are respectively connected to the upper ring cover 11 and the lower ring cover 12. The sampling rod 14 includes an outer cylinder 25 and a middle cylinder 26. The outer cylinder 25 is sleeved outside the middle cylinder 26, and a cooling ring cavity 29 is formed between the outer cylinder 25 and the middle cylinder 26. An installation slot 60 is opened on the outer cylinder 25, and a sampling pipe 30 is inserted into the installation slot 60. The sampling pipe 30 extends in the cooling ring cavity 29 along the direction tangent to the middle cylinder 26. The sampling pipe 30 is provided with ventilation holes, and a flue gas inlet 54 aligned with the ventilation holes is opened on the side of the middle cylinder 26. A partition cylinder 41 is fixedly arranged in the middle cylinder 26. A piston cylinder 51 is slidably arranged below the partition cylinder 41. A detection cavity 56 is formed between the partition cylinder 41 and the piston cylinder 51. The flue gas inlet 54 is communicated with the detection cavity 56. An inner cylinder 27 is longitudinally slidably arranged at the axis of the middle cylinder 26. The inner cylinder 27 is fixedly connected to the piston cylinder 51. A nitrogen oxide detection head 53 is installed on the outer wall of the inner cylinder 27. The nitrogen oxide detection head 53 is located in the detection cavity 56. An exhalation piston 42 is slidably arranged above the partition cylinder 41. An exhalation cavity 43 is formed between the exhalation piston 42 and the partition cylinder 41. The partition cylinder 41 extends downward to be provided with a support rod 49. A traction wire 50 is arranged between the piston cylinder 51 and the exhalation piston 42. The support rod 49 supports the traction wire 50 downward. When the piston cylinder 51 moves upward, the exhalation piston 42 is driven to move downward through the traction wire 50. A jet device communicating with the detection cavity 56 is further arranged in the exhalation cavity 43. The exhalation cavity 43 also has a replenishing flow device. The jet device automatically jets fluid into the detection cavity 56 for cleaning as the volume of the detection cavity 56 shrinks.

[0040] Specifically, the inlet direction of the sampling pipe 30 faces downward, so as to facilitate the entry of flue gas and also facilitate the discharge of internal fluid. The lower ring cover 12 and the upper ring cover 11 have the same structure, both including a central ring 59 and an outer ring 17. The central ring 59 and the outer ring 17 are concentrically arranged, and a plurality of connecting rods 13 are fixedly connected in the annular gap between the central ring 59 and the outer ring 17. An air passage 15 for flue gas to pass through is formed between adjacent two connecting rods 13.

[0041] Preferably, a heat insulation layer 28 is arranged on the outer surface of the outer cylinder 25. The cooling ring cavity 29 is filled with a cooling fluid. A first cover 19 is fixedly arranged at the top of the outer cylinder 25, and a second cover 32 is fixedly arranged at the bottom of the outer cylinder 25. A drain pipe 22 communicating with the cooling ring cavity 29 is arranged on the upper end surface of the first cover 19, and a liquid inlet pipe 34 communicating with the cooling ring cavity 29 is arranged on the lower end surface of the second cover 32.

[0042] In specific implementation, the device further comprises a liquid pump, which is used to replenish low-temperature fluid to the liquid inlet pipe 34, and the liquid discharge pipe 22 is used to discharge high-temperature fluid upward.

[0043] Preferably, the plurality of sampling tubes 30 are longitudinally spirally distributed with the flue tube 10 as the axis, and the sampling tubes 30 include a first sampling tube 62 and a second sampling tube 61, and the first sampling tube 62 and the second sampling tube 61 are connected by an elastic connecting tube 63, and the elastic connecting tube 63 is elastic. A filter cover 64 is detachably provided at the opening of the first sampling tube 62, and a tail plug 66 is fixedly provided at the tail of the second sampling tube 61. The mounting slot 60 and the second sampling tube 61 are combined to form a sampling cavity 65, and the portion of the tail plug 66 extending into the sampling cavity 65 is an inclined surface facing the flue gas inlet 54.

[0044] In this embodiment, in order to facilitate the operator to install the sampling tube 30, when inserting the blind end of the sampling tube 30 into the installation slot 60, the second sampling tube 61 will first hit the middle tube 26. Since the elastic connecting tube 63 is elastic, the second sampling tube 61 can avoid it to a certain extent to facilitate continued insertion until the opening of the side wall of the second sampling tube 61 is aligned with the smoke inlet 54. In order to limit the rotation direction of the sampling tube 30 to ensure that the opening of the side wall of the second sampling tube 61 can be aligned with the smoke inlet 54, a keyway structure is designed on the inner wall of the installation slot 60, and a corresponding keyway structure is designed on the outer wall of the first sampling tube 62 to limit the rotation of the sampling tube 30 around itself.

[0045] Preferably, a middle cylinder cover 69 is fixedly provided at the upper and lower ends of the middle cylinder 26, a sealing hole is opened at the center of the middle cylinder cover 69, the inner cylinder 27 passes through the sealing hole, a motor 21 is fixedly installed on the upper surface of the first cover 19, a driving gear 20 is fixedly provided on the shaft of the motor 21, a passive gear 23 is fixedly provided at the upper end of the inner cylinder 27, and the passive gear 23 is meshed with the driving gear 20.

[0046] In this embodiment, the inner cylinder 27 can move freely up and down or rotate in the sealing hole under the restriction of the sealing hole. The motor 21 provides power for the rotation of the inner cylinder 27. The driving gear 20 extends longitudinally and is specifically a spur gear. The passive gear 23 can slide up and down relative to the driving gear 20 while maintaining a meshing state. The passive gear 23 and the driving gear 20 adopt an axially slidable spur gear meshing structure.

[0047] Preferably, a cable protection shell 37 is installed at the bottom opening of the inner cylinder 27, and a cable connector 36 is arranged in the cable protection shell 37. A detection cable 52 for connecting the nitrogen oxide detection head 53 is arranged in the inner cylinder 27, and the detection cable 52 extends downward and is connected to the cable connector 36. Specifically, a rotatable electrical connector is used to achieve dynamic connection, and a rotating ring 35 is provided at the lower end of the cable protection shell 37, and a mounting plate 33 is fixedly arranged at the lower end of the second cover 32, and a telescopic rod 31 is fixedly installed in the middle of the mounting plate 33, and the telescopic axis of the telescopic rod 31 is rotatably connected to the rotating ring 35.

[0048] Preferably, the jet device includes a jet tube 46 arranged in the exhalation chamber 43, the exhalation piston 42 includes an upper ring body 71 at the top, a movable sleeve 73 in the middle and a lower ring body 72 at the bottom, the movable sleeve 73 is on the outside of the inner tube 27 and slides up and down outside the inner tube 27, the jet tube 46 is sleeved outside the movable sleeve 73, and the lower end of the jet tube 46 is fixedly connected to the lower ring body 72, a gas flow channel 48 is formed between the jet tube 46 and the movable sleeve 73, a limit ring 74 is fixedly provided on the upper side of the jet tube 46, a reset spring 47 for pushing the limit ring 74 to reset upward is provided between the limit ring 74 and the separation tube 41, a one-way jet port is opened on the lower side wall of the jet tube 46, the exhalation piston 42 moves downward to drive the limit ring 74 to move downward, so that the one-way jet port leaks downward into the detection chamber 56.

[0049] Specifically, the one-way jet port includes a through hole formed in the side wall of the jet tube 46 , in which a one-way nozzle is installed, and the spraying direction of the one-way nozzle is toward the detection cavity 56 .

[0050] Preferably, the flow replenishing device includes a one-way opening 44 opened on the upper ring body 71, and an elastic pad 45 is arranged on the lower surface of the upper ring body 71, and the elastic pad 45 elastically covers the lower opening of the one-way opening 44, and the elastic pad 45 can be separated from the opening on the lower side of the one-way opening 44 under the downward force, and an air replenishing cylinder 39 is arranged on the upper side of the exhalation piston 42, and the air replenishing cylinder 39 is fixedly connected to the inner cylinder 27, and a switching groove 58 is arranged on the side wall of the air replenishing cylinder 39, and a liquid replenishing port 38 is arranged on the side wall of the middle cylinder 26, and the rotation of the inner cylinder 27 drives the air replenishing cylinder 39 to rotate synchronously, so that the switching groove 58 is aligned or staggered with the liquid replenishing port 38.

[0051] Preferably, an air inlet pipe is provided at the top opening of the inner cylinder 27, and a solenoid valve 24 is installed in the air inlet pipe. An air replenishment hole 40 is provided on the side wall of the inner cylinder 27, and an air replenishment cavity 75 is formed between the air replenishment cylinder 39 and the exhalation piston 42. The air replenishment hole 40 is located in a position connected to the air replenishment cavity 75.

[0052] Preferably, a longitudinally extending flue gas longitudinal groove 55 is formed in the side wall of the piston cylinder 51. The inner cylinder 27 drives the piston cylinder 51 to rotate so that the flue gas longitudinal groove 55 is staggered or aligned with the flue gas inlet 54.

[0053] Preferably, it further includes a processing module and a display module. The cable connector 36 is connected to the processing module through a cable. The processing module receives and processes the signals from the nitrogen oxide detector 53, and the processing module sends display signals to the display module.

[0054] Usage method of this device:

[0055] First, install this device at the chimney. The flue gas passes through the inside of the flue duct 10 from bottom to top. The upper ring cover 11 and the lower ring cover 12 are provided to fix the sampling rod 14 at the center of the flue gas. The telescopic rod 31 is activated, and the telescopic rod 31 drives the inner cylinder 27 to move downward. The inner cylinder 27 drives the piston cylinder 51 to move downward. Since the position of the partition cylinder 41 remains unchanged, the volume of the detection chamber 56 increases. The external flue gas first enters the sampling pipe 30. Since the sampling pipe 30 is in the cooling ring cavity 29, the temperature of the flue gas is reduced. And since the extending direction of the sampling pipe 30 is tangent to the middle cylinder 26, the length of the sampling pipe 30 in the cooling ring cavity 29 is extended, which is beneficial to further reducing the temperature of the flue gas. The flue gas at an appropriate temperature enters the detection chamber 56 through the flue gas inlet 54 and the flue gas longitudinal groove 55. The nitrogen oxide detector 53 detects the content of nitrogen oxides in the gas and feeds back the detection result to the processing unit through the detection cable 52, completing the action of one air extraction detection.

[0056] Second, after the action of air extraction detection is completed, in order to smoothly discharge the remaining flue gas in the detection chamber 56 and the sampling pipe 30 to facilitate the next detection, this device is specifically provided with an exhalation mode. Specifically, the telescopic rod 31 drives the inner cylinder 27 to move upward and reset. The inner cylinder 27 pulls the traction wire 50. Supported by the support rod 49, the upper end of the traction wire 50 drives the exhalation piston 42 to move downward. At this time, the piston cylinder 51 moves upward, the space of the detection chamber 56 decreases, and the internal residual flue gas is discharged outward through the flue gas inlet 54 and the sampling pipe 30. In order to further reduce the content of the residual gas and improve the accuracy of the next detection, during the upward movement of the piston cylinder 51, the traction wire 50 drives the lower ring body 72 to move downward, so that the jet tube 46 moves downward. The upper ring body 71 moves downward to squeeze the space of the exhalation chamber 43. The air pressure in the exhalation chamber 43 increases, and the return spring 47 is compressed until the one-way jet port on the jet tube 46 leaks downward into the detection chamber 56. The high-pressure gas in the exhalation chamber 43 is ejected downward through the one-way jet port, and the waste gas in the detection chamber 56 is replaced by clean gas, eliminating the cross-contamination of the residual gas to the subsequent detection.

[0057] Thirdly, the dirt in the flue gas will be absorbed in the detection chamber 56. Long-term use will affect the internal cleanliness and reduce the accuracy of the nitrogen oxide detector 53. To overcome this problem, the device is specifically provided with a cleaning mode. Specifically, the motor 21 drives the driving gear 20 to rotate, the driving gear 20 drives the driven gear 23 to rotate, and the driven gear 23 drives the inner cylinder 27 and the air supplement cylinder 39 to rotate by a certain angle so that the switching groove 58 and the liquid supplement port 38 are aligned. There is clean liquid in the cooling ring cavity 29. As the telescopic rod 31 extends upward, the space of the air supplement cavity 75 increases. The liquid in the cooling ring cavity 29 enters the air supplement cavity 75 through the liquid supplement port 38 and the switching groove 58. After a period of time, the motor 21 rotates in the reverse direction to close the liquid supplement port 38 so that a part of air remains in the air supplement cavity 75. An air pump is arranged outside the device. The solenoid valve 24 is opened, and the air pump pumps clean gas into the inner cylinder 27. The clean gas is supplemented into the air supplement cavity 75 through the air supplement hole 40 to increase the air pressure in the air supplement cavity 75. Whenever the exhalation piston 42 moves upward, the elastic pad 45 opens the restriction on the one-way opening 44, and both the liquid and gas in the air supplement cavity 75 can enter the exhalation cavity 43 downward. Whenever the exhalation piston 42 moves downward, the liquid and gas in the exhalation cavity 43 can be sprayed onto the inner wall of the detection chamber 56 at a high speed and circumferentially through the one-way jet orifice to achieve the effect of self-cleaning.

[0058] The embodiments of the present invention are given for purposes of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are chosen and described in order to best explain the principles of the invention and its practical application, and to enable those of ordinary skill in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

Claims

1. An intelligent nitrogen oxide detection system, characterized by: The invention comprises a flue tube and an upper ring cover and a lower ring cover fixedly arranged at the upper and lower ends of the flue tube, a longitudinally extending sampling rod is arranged in the flue tube, the upper and lower ends of the sampling rod are respectively connected with the upper ring cover and the lower ring cover, the sampling rod comprises an outer tube and a middle tube, the outer tube is sleeved on the outer side of the middle tube, and a cooling ring cavity is formed between the outer tube and the middle tube, an installation slot is arranged on the outer tube, a sampling tube is inserted into the installation slot, the sampling tube extends in the cooling ring cavity along a direction tangent to the middle tube, an air vent is arranged on the sampling tube, a smoke inlet aligned with the air vent is arranged on the side of the middle tube, a separation tube is fixedly arranged in the middle tube, and a sliding device is arranged on the lower side of the separation tube A piston cylinder is disposed, a detection chamber is formed between the separation cylinder and the piston cylinder, the smoke inlet is connected to the detection chamber, an inner cylinder is longitudinally slidably arranged at the axis center of the middle cylinder, the inner cylinder is fixedly connected to the piston cylinder, a nitrogen oxide detection head is installed on the outer wall of the inner cylinder, the nitrogen oxide detection head is in the detection chamber, an exhalation piston is slidably arranged on the upper side of the separation cylinder, an exhalation chamber is formed between the exhalation piston and the separation cylinder, a support rod is extended downwardly from the separation cylinder, a traction line is arranged between the piston cylinder and the exhalation piston, the support rod supports the traction line downwardly, a jet device connected to the detection chamber is also arranged in the exhalation chamber, and the exhalation chamber also has a supplementary flow device; The outer surface of the outer cylinder is provided with a heat-insulating layer, the cooling ring cavity is filled with a cooling fluid, a first cover is fixedly provided on the top of the outer cylinder, a second cover is fixedly provided on the bottom of the outer cylinder, a liquid discharge pipe connected to the cooling ring cavity is provided on the upper end surface of the first cover, and a liquid inlet pipe connected to the cooling ring cavity is provided on the lower end surface of the second cover; The plurality of sampling tubes are longitudinally spirally distributed with the flue tube as the axis, the sampling tubes include a first sampling tube and a second sampling tube, the first sampling tube and the second sampling tube are connected by an elastic connecting tube, the elastic connecting tube is elastic, a filter cover is detachably provided at the opening of the first sampling tube, a tail plug is fixedly provided at the tail of the second sampling tube, the mounting slot and the second sampling tube are combined to form a sampling cavity, the portion of the tail plug extending into the sampling cavity is an inclined surface facing the flue gas inlet.

2. The intelligent nitrogen oxide detection system according to claim 1, characterized in that: The middle cylinder covers are fixedly arranged at the upper and lower ends of the middle cylinder, a sealing hole is provided at the center of the middle cylinder cover, the inner cylinder passes through the sealing hole, a motor is fixedly installed on the upper surface of the first cover, a driving gear is fixedly arranged on the shaft of the motor, a passive gear is fixedly arranged on the upper end of the inner cylinder, and the passive gear is meshed with the driving gear.

3. The intelligent nitrogen oxide detection system according to claim 1 is characterized in that: A cable protection shell is installed at the bottom opening of the inner cylinder, a cable connector is arranged in the cable protection shell, a detection cable for connecting the nitrogen oxide detection head is arranged in the inner cylinder, the detection cable extends downward and is connected to the cable connector, a rotating ring is arranged at the lower end of the cable protection shell, a mounting plate is fixedly arranged at the lower end of the second cover, a telescopic rod is fixedly arranged in the middle of the mounting plate, and the telescopic shaft of the telescopic rod is rotatably connected to the rotating ring.

4. The intelligent nitrogen oxide detection system according to claim 1 is characterized in that: The jet device includes a jet tube arranged in the exhalation chamber, the exhalation piston includes an upper ring body at the top, a movable sleeve in the middle and a lower ring body at the bottom, the movable sleeve is on the outside of the inner tube and slides up and down outside the inner tube, the jet tube is sleeved outside the movable sleeve, and the lower end of the jet tube is fixedly connected to the lower ring body, a gas flow channel is formed between the jet tube and the movable sleeve, a limit ring is fixedly provided on the upper side of the jet tube, a reset spring for pushing the limit ring to reset upward is provided between the limit ring and the separation tube, a one-way jet port is opened on the lower side wall of the jet tube, and the downward movement of the exhalation piston drives the limit ring to move downward, so that the one-way jet port leaks downward into the detection chamber.

5. The intelligent nitrogen oxide detection system according to claim 4 is characterized in that: The flow replenishment device includes a one-way opening formed on the upper ring body, an elastic pad is arranged on the lower surface of the upper ring body, the elastic pad elastically covers the lower opening of the one-way opening, and the elastic pad can be separated from the opening on the lower side of the one-way opening by a downward force, an air replenishment cylinder is arranged on the upper side of the exhalation piston, the air replenishment cylinder is fixedly connected to the inner cylinder, a switching groove is arranged on the side wall of the air replenishment cylinder, and a liquid replenishment port is arranged on the side wall of the middle cylinder, and the rotation of the inner cylinder drives the air replenishment cylinder to rotate synchronously so that the switching groove is aligned with or staggered with the liquid replenishment port.

6. The intelligent nitrogen oxide detection system according to claim 5, characterized in that: An air inlet pipe is arranged at the top opening of the inner cylinder, a solenoid valve is installed in the air inlet pipe, an air replenishment hole is arranged on the side wall of the inner cylinder, an air replenishment cavity is formed between the air replenishment cylinder and the exhalation piston, and the air replenishment hole is located in a position connected to the air replenishment cavity.

7. The intelligent nitrogen oxide detection system according to claim 1 is characterized in that: The side wall of the piston cylinder is provided with a longitudinal flue gas groove extending longitudinally, and the inner cylinder drives the piston cylinder to rotate so that the longitudinal flue gas groove is staggered or aligned with the flue gas inlet.

8. The intelligent nitrogen oxide detection system according to claim 3 is characterized by: It also includes a processing module and a display module. The cable connector is connected to the processing module via a cable. The processing module receives and processes the signal from the nitrogen oxide detection head. The processing module sends a display signal to the display module.

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