Rotary air preheater

Abstract

The invention provides a rotary air preheater, and relates to the technical field of rotary air preheaters, the rotary air preheater comprises a rotor and a shell, the rotor is mounted on a driving device, the shell is arranged on the peripheral side of the rotor, and a sealing mechanism is arranged on the rotor. The driving device is arranged to be connected with the rotor and drive the rotor to rotate in the shell so as to be matched with the rotary air preheater to complete heat exchange of air, the sealing mechanism can complete effective sealing of the waste heat bin of the air preheater, the air preheater has the extremely low air leakage rate, the friction phenomenon is avoided, and the service life of the air preheater is prolonged. And long-term safe and stable operation of the air pre-heater in the overhaul interval is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of rotary air preheaters, and in particular to a rotary air preheater. Background Art

[0002] For a long time, my country's power structure has been dominated by coal-fired power, among which rotary air preheaters are widely used in large and medium-sized power station boilers, and air leakage rate is one of its important economic indicators. Effectively controlling the air preheater air leakage rate can achieve energy-saving benefits in two aspects: reducing the power consumption of primary fans, forced draft fans, and induced draft fans, and improving boiler efficiency.

[0003] Whether it is domestic or foreign air preheater manufacturers or the majority of air preheater users, they are all working hard to reduce the air leakage rate of air preheaters from different aspects. Traditional sealing technologies have more or less problems, such as complex structure, short service life, unreliable performance, etc., and there is a most basic problem that has not been overcome, that is, passively adapting to the mushroom-shaped deformation of the air preheater rotor, and not actively eliminating the impact of the mushroom-shaped deformation of the air preheater rotor, that is, there is always a problem of high air leakage rate at low and medium loads, especially under the current low load rate conditions in the power industry, this problem is particularly prominent. Therefore, it is urgent to design a rotary air preheater to solve the above problems. Summary of the invention

[0004] The present invention provides a rotary air preheater to solve at least one of the problems raised by the above background technology.

[0005] To solve the above technical problems, the present invention discloses a rotary air preheater, comprising a rotor and a casing, wherein the rotor is fixedly connected to a driving device, the casing is arranged on the circumference of the rotor, and a sealing mechanism is arranged on the rotor.

[0006] Preferably, the rotor includes a center cylinder and an outer cylinder, the center cylinder is axially mounted on the rotating shaft, and the lower end of the rotating shaft is fixedly connected to the driving device, the outer cylinder is sleeved outside the center cylinder, the outer wall of the outer cylinder is slidably connected to the inner wall of the outer shell, the outer cylinder and the center cylinder are fixedly connected by a plurality of grid plates arranged at intervals along the circumferential direction of the center cylinder, and the heat exchange unit is arranged in a space enclosed by the center cylinder, the outer cylinder and the grid plates.

[0007] Preferably, it further comprises a plurality of fan-shaped plates, wherein the fixed ends of the plurality of fan-shaped plates are arranged at intervals along the circumference of the central tube, and the outer ends of the plurality of fan-shaped plates are slidably connected to the top of the outer tube.

[0008] Preferably, the sealing mechanism includes: a flexible sealing sheet and a non-bending and deforming mounting plate, the non-bending and deforming mounting plate is fixedly mounted on the top of the lattice plate through a fixing rod on one side, the flexible sealing sheet is fixedly mounted on the top of the non-bending and deforming mounting plate, two clamping plates are arranged on both sides of the front and rear of the non-bending and deforming mounting plate, the bottom of the non-bending and deforming mounting plate is fixedly mounted to the top of the lattice plate through two clamping plates, the non-deformable plate sealing sheet is fixedly mounted on one side of the top of the lattice plate, and the bottom of one side of the non-bending and deforming mounting plate is embedded in the upper part of the non-deformable plate sealing sheet.

[0009] Preferably, it also includes a flue gas heat exchange performance detection device, which is used to detect the state of the rotary air preheater when the flue gas heat exchange is performed after the sealing mechanism is used. The flue gas heat exchange performance detection device includes:

[0010] Photoelectric sensor, used to detect the speed of rotation of the rotating shaft in the rotary air preheater;

[0011] Pressure sensor 1, used to detect the pressure at the air inlet of the rotary air preheater;

[0012] Pressure sensor 2, used to detect the pressure at the flue gas inlet of the rotary air preheater;

[0013] Densitometer, used to detect the density of flue gas in the rotary air preheater;

[0014] A speed sensor, used to detect the speed of leaked air flowing through the gap at the sealing mechanism;

[0015] A controller and an alarm, wherein the controller is electrically connected to a photoelectric sensor, a pressure sensor 1, a pressure sensor 2, a density meter, a speed sensor and an alarm, and the controller controls the operation of the alarm based on the photoelectric sensor, the pressure sensor 1, the pressure sensor 2, the density meter and the speed sensor.

[0016] Preferably, the controller controls the alarm to work based on the photoelectric sensor, the first pressure sensor, the second pressure sensor, the density meter, and the speed sensor, including the following steps:

[0017] Step 1: Based on formula (1) and the detection values ​​of the photoelectric sensor, pressure sensor 1, pressure sensor 2 and density meter, calculate the area S of the gap generated when the rotary air preheater uses the sealing mechanism for flue gas heat exchange:

[0018]

[0019] Wherein, S is the area of ​​the gap generated when the rotary air preheater uses a sealing mechanism for flue gas heat exchange, n is the detection value of the photoelectric sensor for the rotation speed of the rotating shaft in the rotary air preheater, D is the diameter of the rotor, d is the diameter of the rotor center tube, H is the height of the rotor, λ is the proportion of the volume occupied by the metal inside the rotor, P1 is the detection value of the pressure at the air inlet of the rotary air preheater by the pressure sensor one, P2 is the detection value of the pressure at the flue gas inlet of the rotary air preheater by the pressure sensor two, ρ is the detection value of the density of the flue gas exchanged in the rotary air preheater by the density meter, and ε is the resistance coefficient of the flue gas;

[0020] Step 2: According to the following formula (2) and the detection value of the speed sensor, the actual pressure drop loss W of the current rotary air preheater when the sealing mechanism is used for flue gas heat exchange is calculated. The controller compares the actual pressure drop loss W of the current rotary air preheater when the sealing mechanism is used for flue gas heat exchange with the preset pressure drop loss range. When the actual pressure drop loss is lower than the preset pressure drop loss range, the controller controls the alarm to sound an alarm:

[0021]

[0022] Wherein, W is the actual pressure drop loss when the rotary air preheater uses the sealing mechanism (3) for flue gas heat exchange, B is the thickness of the compartment grid plate (7), μ is the air dynamic viscosity, V is the speed sensor's detection value of the speed of the leaking air flowing through the gap at the sealing mechanism (3), L is the length of the flexible sealing sheet, K is the viscous resistance coefficient of the flue gas, and C is the inertial resistance coefficient of the flue gas.

[0023] The rotary air preheater provided by the present invention has the following beneficial effects compared with the prior art:

[0024] 1. The sealing technology used in the above-mentioned rotary air preheater is a non-deformation constant air leakage rate sealing technology. This technology adds a new non-bending and deforming mounting plate on the hot end compartment grid plate, and connects it to the top of the compartment grid plate through a fixing rod. The non-bending and deforming mounting plate and the compartment grid plate are fixed by lateral supports to form a frame structure. There is no temperature difference between the upper and lower parts during hot operation, so no bending and deformation will occur, and it will only expand along the radial direction of the air preheater. No matter how the air preheater deforms, the non-deformation plate sealing piece installed on the non-bending and deforming mounting plate can keep the sealing gap between the cold set fan-shaped plate basically unchanged. This technical means actively eliminates the influence of the mushroom-shaped deformation of the air preheater, and changes the previous other sealing technologies to passively adapt to the mushroom-shaped deformation, so as to achieve a different from the ordinary rotary air preheater sealing technology that can only guarantee the air leakage rate of the full load section, and achieve the rotary air preheater to maintain a long-term low air leakage rate in the full load section, and the structure is ingenious and reliable, and there is no dynamic and static friction, which is a revolutionary progress in the air preheater sealing technology.

[0025] 2. The above sealing technology can keep the air leakage rate of different load sections basically constant, varying between 4% and 4.5%, and there is still room for further decline; secondly, it is basically maintenance-free; thirdly, it has reliable performance, controllable sealing gap, and the sealing sheet will not scratch the fan plate. The sealing effect is long-term and stable, and the service life is long. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic structural diagram of a rotary air preheater provided in an embodiment of the present invention;

[0028] Figure 2 A structural schematic diagram of the sealing principle of a sealing mechanism of a rotary air preheater provided in an embodiment of the present invention;

[0029] Figure 3 for Figure 2 The structural diagram of the sealing principle of the middle sealing mechanism from the right;

[0030] Figure 4 A schematic structural diagram of a cleaning mechanism for a rotary air preheater provided in an embodiment of the present invention.

[0031] Reference numerals:

[0032] 1. Rotor; 2. Shell; 3. Sealing mechanism; 4. Center tube; 5. Outer tube; 6. Rotating shaft; 7. Grid plate; 8. Heat exchange unit; 9. Fan plate; 10. Flexible sealing sheet; 11. Non-bending and deforming mounting plate; 12. Fixing rod; 13. Clamping plate; 14. Non-deformation plate sealing sheet; 15. Cleaning mechanism; 16. Fixing plate; 17. Universal wheel; 18. Auxiliary box; 19. Feeding bin; 20. Crushing roller; 21. Support plate; 22. Feeding box; 23. Driving motor; 24. Stirring rod; 25. Mounting frame; 26. Dry ice storage box; 27. Air compressor; 28. Air dryer; 29. ​​Connector; 30. Dry ice delivery pipe; 31. Nozzle body; 32. Air curtain protective cover; 33. Dry ice fluid; 34. Protective air curtain; 35. Nozzle. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The present invention provides the following embodiments

[0035] Example 1

[0036] The embodiment of the present invention provides a rotary air preheater, such as Figure 1-Figure 3 As shown, it includes a rotor 1 and a housing 2 , wherein the rotor 1 is mounted on a driving device, and the housing 2 is arranged on the circumferential side of the rotor 1 , and a sealing mechanism 3 is arranged on the rotor 1 .

[0037] Optionally, the driving device includes an electric motor, a reduction device, a central driving device, a torque arm, a support and a driving shaft.

[0038] Preferably, the rotor 1 includes a center tube 4 and an outer tube 5, the center tube 4 is axially mounted on the rotating shaft 6, and the lower end of the rotating shaft 6 is fixedly connected to the driving device, the outer tube 5 is sleeved outside the center tube 4, the outer wall of the outer tube 5 is slidably connected to the inner wall of the outer shell 2, the outer tube 5 and the center tube 4 are fixedly connected by a plurality of grid plates 7 arranged at intervals along the circumferential direction of the center tube 4, and the heat exchange unit 8 is arranged in a space enclosed by the center tube 4, the outer tube 5 and the grid plates 7.

[0039] Preferably, it further comprises a plurality of fan-shaped plates 9 , wherein the fixed ends of the plurality of fan-shaped plates 9 are arranged at intervals along the circumference of the central tube 4 , and the outer ends of the plurality of fan-shaped plates 9 are slidably connected to the top of the outer tube 5 .

[0040] Preferably, the sealing mechanism 3 includes: a flexible sealing sheet 10 and a non-bending and deforming mounting plate 11, the non-bending and deforming mounting plate 11 is fixedly mounted on the top of the compartment grid plate 7 through a fixing rod 12 on one side, the flexible sealing sheet 10 is fixedly mounted on the top of the non-bending and deforming mounting plate 11, two clamping plates 13 are arranged on both sides of the front and rear of the non-bending and deforming mounting plate 11, the bottom of the non-bending and deforming mounting plate 11 and the top of the compartment grid plate 7 are fixedly mounted through two clamping plates 13, a non-deformable plate sealing sheet 14 is fixedly mounted on one side of the top of the compartment grid plate 7, and the bottom of one side of the non-bending and deforming mounting plate 11 is embedded in the upper part of the non-deformable plate sealing sheet 14.

[0041] The working principle and beneficial effects of the above technical solution are:

[0042] A rotary air preheater of the present invention is mainly composed of a rotor 1, a shell 2, a driving device and a sealing mechanism 3. The sealing mechanism 3 is a movable non-bending and deforming mounting plate 11 installed above the hot end bin grid plate 7, so that the radial flexible sealing sheet 10 of the hot end rotor 1 and the shell 2 can still maintain a position close to that of the cold state in a hot state, reducing the gap between the fan plate 9 and the flexible sealing sheet 10, and the movable sealing sheet mounting plate and the original bin partition adopt corresponding sealing means; this design not only makes the air preheater have an extremely low air leakage rate, but also does not cause friction, ensuring the long-term safe and stable operation of the air preheater during the overhaul interval; secondly, the non-bending and deforming mounting plate 11 is fixed above the bin grid plate 7 by a fixing rod 12, so that the non-bending and deforming mounting plates 11 are fixed by lateral supports to form a frame structure, thereby achieving a sealing effect.

[0043] Among them, the driving device is responsible for driving the rotor 1 of the preheater to rotate, so as to achieve the efficiency of heat exchange; the motor converts electrical energy into mechanical energy to provide power for the rotation of the rotary air preheater; the reduction device is usually composed of transmission elements such as gears, belts or chains, which can effectively convert the high-speed rotation of the motor into the low-speed rotation required by the rotary air preheater; the central driving device directly drives the rotor 1 to rotate, and is usually connected to the top end shaft of the rotor 1, and drives the rotor 1 to rotate through the torque transmitted by the reduction device; the torque arm is an important component connected between the driving device and the top structure, which can transmit the torque generated by the driving device to the rotor 1 of the preheater, and the torque arm support is a component that supports the torque arm to ensure that the torque arm can remain stable when transmitting torque; the drive shaft is a key component connecting the motor, the reduction device and the central driving device, and is responsible for transmitting the rotational power of the motor to the rotor 1 of the rotary air preheater.

[0044] The sealing mechanism 3 actively controls the mushroom-shaped deformation of the air preheater rotor 1, that is, a non-bending and deforming mounting plate 11 with no temperature difference between the upper and lower parts is installed above the radial compartment grid plate 7 at the hot end of the air preheater, and the hot end flexible sealing sheet 10 is installed on this plate, so that the sealing gaps in the cold and hot states are basically consistent. The principle of non-deformation is that the non-bending and deforming mounting plate 11 is installed outside the coverage of the heat exchange element of the air preheater. There is no temperature difference between the upper and lower parts during hot operation, and its deformation is zero, so no bending and deformation will occur, and it will only expand along the radial direction of the air preheater. No matter how the air preheater is deformed, the non-bending and deforming mounting plate 11 can keep the sealing gap basically unchanged with the cold state setting.

[0045] The sealing technology used in the above-mentioned rotary air preheater is a non-deformation constant leakage rate sealing technology. This technology adds a new non-bending and deforming mounting plate 11 on the hot end compartment grid plate 7, and connects it to the top of the compartment grid plate 7 through a fixing rod 12. The non-bending and deforming mounting plate 11 and the compartment grid plate 7 are fixed by lateral supports to form a frame structure. There is no temperature difference between the upper and lower parts during hot operation, so no bending and deformation will occur, and it will only expand along the radial direction of the air preheater. No matter how the air preheater deforms, the non-deformation plate sealing piece 14 installed on the non-bending and deforming mounting plate 11 can keep the sealing gap with the cold setting fan-shaped plate 9 basically unchanged. This technical means actively eliminates the influence of the mushroom-shaped deformation of the air preheater, and changes the previous other sealing technologies to passively adapt to the mushroom-shaped deformation, so as to achieve a different from the ordinary rotary air preheater sealing technology that can only guarantee the leakage rate of the full load section, and obtain the rotary air preheater to maintain a long-term low leakage rate in the full load section, and the structure is ingenious and reliable, and there is no dynamic and static friction, which is a revolutionary progress in the air preheater sealing technology. At the same time, the above sealing technology has the following advantages: firstly, the air leakage rate in different load sections is basically constant, varying between 4% and 4.5%, and there is still room for further decline; secondly, it is basically maintenance-free; thirdly, the performance is reliable, the sealing gap is controllable, the sealing sheet will not scratch the fan plate 9, the sealing effect is long-term and stable, and the service life is long.

[0046] Example 2

[0047] On the basis of Example 1, Figure 4 As shown, optionally, a cleaning mechanism 15 is also included, and the cleaning mechanism 15 is used for cleaning the inside of the rotor 1. The cleaning mechanism 15 includes: a fixed plate 16, a plurality of universal wheels 17 are installed at the bottom of the fixed plate 16, an auxiliary box 18 is fixedly connected to the top of the fixed plate 16, a feeding bin 19 is fixedly installed on the top of the auxiliary box 18, and two crushing rollers 20 are installed at the lower part of the feeding bin 19, and the two crushing rollers 20 are driven by a driving device, a support plate 21 is fixedly installed on the inner wall of the auxiliary box 18, a feeding box 22 is embedded in the top of the support plate 21, a driving motor 23 is fixedly installed on the inner wall of the auxiliary box 18, and the output shaft of the driving motor 23 rotates through the side wall of the feeding box 22 and is fixedly installed with a stirring rod 24, and one end of the stirring rod 24 is rotatably connected to the inner wall of the feeding box 22.

[0048] Preferably, it further comprises a mounting frame 25, the mounting frame 25 is fixedly mounted on the top of the fixing plate 16, and a dry ice storage box 26 and an air compressor 27 are mounted on the mounting frame 25, an air dryer 28 is fixedly mounted on the top of the fixing plate 16, a feed port of a connector 29 is communicated with a discharge port of the feed box 22, and the air compressor 27, the air dryer 28 and the connector 29 are communicated, a discharge port of the connector 29 is connected with a dry ice delivery pipe 30, and a nozzle assembly is connected at the discharge port of the dry ice delivery pipe 30;

[0049] The nozzle assembly includes a nozzle body 31 and an air curtain protective cover 32. The nozzle body 31 is embedded in the nozzle body 31 and is connected to the discharge port of the dry ice delivery pipe 30. The air curtain protective cover 32 forms a protective air curtain 34 surrounding the dry ice fluid 33 at the injection point of the nozzle body. The nozzle 35 is at one end of the air curtain protective cover 32.

[0050] The working principle and beneficial effects of the above technical solution are:

[0051] The cleaning mechanism 15 provided above can be used for effective cleaning of the inside of the rotor 1, and can effectively remove impurities such as dust and dirt accumulated during operation, so as to prevent impurities from reducing the heat transfer efficiency of the preheater, increasing energy consumption, and even causing equipment failure. The plurality of universal wheels 17 provided at the bottom of the fixed plate 16 can facilitate the movement of the working position of the cleaning mechanism 15, thereby completing the cleaning of the rotor 1 inside the rotary air preheater; first, a certain amount of dry ice is taken out from the dry ice storage box 26 provided on the mounting frame 25 and added to the feeding bin 19, and the dry ice is crushed by two crushing rollers 20 provided in the feeding bin 19. The driving device drives the two crushing rollers 20 to crush the dry ice into the required particle size, and then the dry ice in the feeding bin 19 is transported to the feeding bin 22 for standby use. At the same time, the driving motor 23 is started, driving the stirring rod 24 fixedly connected to the output shaft of the driving motor 23 to stir the dry ice entering the feeding bin 22. Continuous stirring prevents the dry ice particles from agglomerating and affecting use. At the same time, the air compressor 27 compresses the air, and after drying by the air dryer 28, high-pressure gas is formed and passed into the connector 29. When cleaning is required, only the nozzle assembly needs to be opened. At this time, the dry ice is brought into the nozzle assembly by the high-pressure gas through the dry ice delivery pipe 30. At this time, the dry ice particles pass through the nozzle body 31, and the air curtain protective cover 32 forms a protective air curtain 34 surrounding the dry ice fluid 33 at the injection point of the nozzle body 31. Under the action of the air curtain protective cover 32, the protective gas is simultaneously transported to the air curtain protective cover 32 to realize the dry ice fluid 33 being ejected from the nozzle 35, thereby completing the effective cleaning of the rotor 1 to be cleaned.

[0052] The above-mentioned dry ice cleaning mechanism uses compressed air as a power and carrier to accelerate dry ice particles to a high speed, and sprays them onto the surface of the rotor 1 to be cleaned through a special spray assembly. During the spraying process, the dynamic changes, sublimation, melting and other energy conversions of the dry ice particles cause the dirt, grease, and residual impurities on the surface of the object to be cleaned to be quickly frozen, condensed, embrittled and peeled off, and are removed with the airflow. No water or chemical cleaning agents are required during the dry ice cleaning process, which helps to reduce the demand for water resources and dependence on chemical substances. At the same time, it can be carried out without disassembling equipment or machinery, reducing downtime and production interruptions. The cleaning mechanism can effectively clean the dust, scale and other impurities accumulated on the rotor 1 of the rotary air preheater during operation, avoiding impurities from reducing the heat transfer efficiency of the preheater, thereby increasing energy consumption and causing equipment failure. Therefore, regular cleaning of the rotor 1 is essential to maintaining the good operating condition of the preheater.

[0053] Example 3

[0054] A rotary air preheater described on the basis of Embodiment 1 or 2 further includes a flue gas heat exchange performance detection device, which is used to detect the state of the rotary air preheater when the flue gas heat exchange is performed after the sealing mechanism 3 is used, and the flue gas heat exchange performance detection device includes:

[0055] A photoelectric sensor for detecting the rotation speed of the rotating shaft 6 in the rotary air preheater;

[0056] Pressure sensor 1, used to detect the pressure at the air inlet of the rotary air preheater;

[0057] Pressure sensor 2, used to detect the pressure at the flue gas inlet of the rotary air preheater;

[0058] Densitometer, used to detect the density of flue gas in the rotary air preheater;

[0059] A speed sensor is used to detect the speed of the leaked air when it flows through the gaps at 3 locations of the sealing mechanism;

[0060] A controller and an alarm, wherein the controller is electrically connected to a photoelectric sensor, a pressure sensor 1, a pressure sensor 2, a density meter, a speed sensor and an alarm, and the controller controls the operation of the alarm based on the photoelectric sensor, the pressure sensor 1, the pressure sensor 2, the density meter and the speed sensor.

[0061] Preferably, the controller controls the alarm to work based on the photoelectric sensor, the first pressure sensor, the second pressure sensor, the density meter, and the speed sensor, including the following steps:

[0062] Step 1: According to formula (1) and the detection values ​​of the photoelectric sensor, pressure sensor 1, pressure sensor 2 and density meter, calculate the area S of the gap generated when the rotary air preheater uses the sealing mechanism 3 for flue gas heat exchange:

[0063]

[0064] Wherein, S is the area of ​​the gap generated when the rotary air preheater uses the sealing mechanism 3 for flue gas heat exchange, n is the detection value of the photoelectric sensor for the rotation speed of the rotating shaft 6 in the rotary air preheater, D is the diameter of the rotor 1, d is the diameter of the central tube 4 of the rotor 1, H is the height of the rotor, λ is the proportion of the volume occupied by the metal inside the rotor 1, P1 is the detection value of the pressure at the air inlet of the rotary air preheater by the pressure sensor one, P2 is the detection value of the pressure at the flue gas inlet of the rotary air preheater by the pressure sensor two, ρ is the detection value of the density of the flue gas exchanged in the rotary air preheater by the density meter, and ε is the resistance coefficient of the flue gas (obtained by looking up the table);

[0065] Step 2: According to the following formula (2) and the detection value of the speed sensor, the actual pressure drop loss W of the current rotary air preheater when the sealing mechanism 3 is used for flue gas heat exchange is calculated. The controller compares the actual pressure drop loss W of the current rotary air preheater when the sealing mechanism 3 is used for flue gas heat exchange with the preset pressure drop loss range. When the actual pressure drop loss is lower than the preset pressure drop loss range, the controller controls the alarm to sound an alarm:

[0066]

[0067] Among them, W is the actual pressure drop loss when the current rotary air preheater uses the sealing mechanism 3 for flue gas heat exchange, B is the thickness of the compartment grid 7, μ is the air dynamic viscosity (obtained by looking up the table), V is the detection value of the speed sensor for the speed of the leaked air flowing through the gap of the sealing mechanism 3, L is the length of the flexible sealing sheet 10, K is the viscous resistance coefficient of the flue gas (obtained by looking up the table), and C is the inertial resistance coefficient of the flue gas.

[0068] The working principle and beneficial effects of the above technical solution are:

[0069] According to formula (1) and the detection values ​​of the photoelectric sensor, pressure sensor 1, pressure sensor 2 and density meter, the area of ​​the gap generated when the rotary air preheater uses the sealing mechanism 3 for flue gas heat exchange is calculated, and the calculation result is more accurate and reliable by comprehensively considering the rotation speed of the rotating shaft 6 in the rotary air preheater, the diameter of the rotor 1, the diameter of the central tube 4 of the rotor 1, the height of the rotor 1, the proportion of the volume occupied by the metal inside the rotor 1, the pressure at the air inlet of the rotary air preheater, the pressure at the flue gas inlet of the rotary air preheater, the density of the flue gas exchanged in the rotary air preheater, and the resistance coefficient of the flue gas;

[0070] Then, according to formula (2) and the detection value of the speed sensor, the actual pressure drop loss when the current rotary air preheater uses the sealing mechanism 3 for flue gas heat exchange is calculated, and the thickness of the compartment grid plate 7, the air dynamic viscosity, the speed of the leaked air flowing through the gap of the sealing mechanism 3, the length of the flexible sealing sheet, the viscous resistance coefficient of the flue gas, and the inertial resistance coefficient of the flue gas are comprehensively considered to make the calculation result more accurate and reliable;

[0071] The controller controls the alarm based on the photoelectric sensor, pressure sensor 1, pressure sensor 2, density meter and speed sensor. If the actual pressure drop loss when the current rotary air preheater uses the sealing mechanism 3 for flue gas heat exchange is not within the preset pressure drop loss range, the controller controls the alarm to sound an alarm, thereby reminding the staff to promptly check the sealing mechanism 3 in the rotary air preheater, and perform maintenance on the sealing mechanism 3 according to the actual inspection results to maintain the use requirements of the rotary air preheater for the sealing mechanism 3, while ensuring the normal operation of the sealing mechanism 3 in the rotary air preheater and a good sealing effect, and effectively reducing the air leakage of the rotary air preheater, further meeting the use requirements of the rotary air preheater for operational reliability and economy, and by real-time monitoring of the working status of the sealing mechanism 3 during operation, not only the flue gas heat exchange efficiency of the sealing mechanism 3 in the rotary air preheater is guaranteed, but also the sealing mechanism 3 can be quickly discovered and repaired in time after a failure occurs.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rotary air preheater, characterized in that: The invention comprises a rotor (1) and a housing (2), wherein the rotor (1) is mounted on a driving device, the housing (2) is arranged on the peripheral side of the rotor (1), and a sealing mechanism (3) is arranged on the rotor (1).

2. A rotary air preheater according to claim 1, characterized in that: The rotor (1) comprises a central tube (4) and an outer tube (5); the central tube (4) is axially mounted on the rotating shaft (6), and the lower end of the rotating shaft (6) is fixedly connected to the driving device; the outer tube (5) is sleeved outside the central tube (4); the outer wall of the outer tube (5) is slidably connected to the inner wall of the outer shell (2); the outer tube (5) and the central tube (4) are fixedly connected via a plurality of compartment grid plates (7) spaced apart along the circumferential direction of the central tube (4); and the heat exchange unit (8) is arranged in a space enclosed by the central tube (4), the outer tube (5) and the compartment grid plates (7).

3. A rotary air preheater according to claim 2, characterized in that: It also includes a plurality of fan-shaped plates (9), wherein the fixed ends of the plurality of fan-shaped plates (9) are arranged at intervals along the circumference of the central tube (4), and the outer ends of the plurality of fan-shaped plates (9) are slidably connected to the top of the outer tube (5).

4. A rotary air preheater according to claim 1, characterized in that: The sealing mechanism (3) comprises: a flexible sealing sheet (10) and a non-bending and deforming mounting plate (11); the non-bending and deforming mounting plate (11) is fixedly mounted on the top of the compartment grid plate (7) through a fixing rod (12) on one side; the flexible sealing sheet (10) is fixedly mounted on the top of the non-bending and deforming mounting plate (11); two clamping plates (13) are arranged on both sides of the non-bending and deforming mounting plate (11); the bottom of the non-bending and deforming mounting plate (11) and the top of the compartment grid plate (7) are fixedly mounted through the two clamping plates (13); the non-deformable plate sealing sheet (14) is fixedly mounted on one side of the top of the compartment grid plate (7); and the bottom of one side of the non-bending and deforming mounting plate (11) is embedded in the upper part of the non-deformable plate sealing sheet (14).

5. A rotary air preheater according to claim 1, characterized in that: The invention also comprises a flue gas heat exchange performance detection device, which is used to detect the state of the rotary air preheater when the flue gas heat exchange is carried out after the sealing mechanism (3) is used. The flue gas heat exchange performance detection device comprises: A photoelectric sensor for detecting the rotation speed of a rotating shaft (6) in a rotary air preheater; Pressure sensor 1, used to detect the pressure at the air inlet of the rotary air preheater; Pressure sensor 2, used to detect the pressure at the flue gas inlet of the rotary air preheater; Densitometer, used to detect the density of flue gas in the rotary air preheater; A speed sensor for detecting the speed of the leaking air when it flows through the gap at the sealing mechanism (3); A controller and an alarm, wherein the controller is electrically connected to a photoelectric sensor, a pressure sensor 1, a pressure sensor 2, a density meter, a speed sensor and an alarm, and the controller controls the operation of the alarm based on the photoelectric sensor, the pressure sensor 1, the pressure sensor 2, the density meter and the speed sensor.

6. A rotary air preheater according to claim 5, characterized in that: The controller controls the alarm to work based on the photoelectric sensor, the first pressure sensor, the second pressure sensor, the density meter, and the speed sensor, including the following steps: Step 1: Based on formula (1) and the detection values ​​of the photoelectric sensor, pressure sensor 1, pressure sensor 2 and density meter, calculate the area S of the gap generated when the rotary air preheater uses the sealing mechanism (3) for flue gas heat exchange: Wherein, S is the area of ​​the gap generated when the rotary air preheater uses the sealing mechanism (3) for flue gas heat exchange, n is the detection value of the rotation speed of the rotating shaft (6) in the rotary air preheater by the photoelectric sensor, D is the diameter of the rotor (1), d is the diameter of the central tube (4) of the rotor (1), H is the height of the rotor (1), λ is the proportion of the volume occupied by the metal inside the rotor (1), P1 is the detection value of the pressure at the air inlet of the rotary air preheater by the pressure sensor one, P2 is the detection value of the pressure at the flue gas inlet of the rotary air preheater by the pressure sensor two, ρ is the detection value of the density of the flue gas exchanged in the rotary air preheater by the density meter, and ε is the resistance coefficient of the flue gas; Step 2: According to the following formula (2) and the detection value of the speed sensor, the actual pressure drop loss W of the current rotary air preheater when the sealing mechanism (3) is used for flue gas heat exchange is calculated. The controller compares the actual pressure drop loss W of the current rotary air preheater when the sealing mechanism (3) is used for flue gas heat exchange with the preset pressure drop loss range. When the actual pressure drop loss is lower than the preset pressure drop loss range, the controller controls the alarm to sound an alarm: Wherein, W is the actual pressure drop loss when the current rotary air preheater uses the sealing mechanism (3) for flue gas heat exchange, B is the thickness of the compartment grid plate (7), μ is the air dynamic viscosity, V is the speed sensor's detection value of the leaking air flowing through the gap at the sealing mechanism (3), L is the length of the flexible sealing sheet (10), K is the viscous resistance coefficient of the flue gas, and C is the inertial resistance coefficient of the flue gas.

Images