On-line ash removal method for tubular heat exchanger

Abstract

The invention relates to an on-line ash removal method for a tubular heat exchanger, which is characterized in that a side spray hole is arranged on one side of a flue provided with the tubular heat exchanger, the side spray hole is composed of a plurality of spray holes arranged at intervals, and each spray hole is sealed by a baffle arranged in the flue; during dust removal, high-pressure gas sprayed by the high-pressure gas spray gun is used for blowing away the baffle for sealing the spray hole and performing high-pressure injection on the heat exchange tube; the blowing position, blowing time and blowing frequency can be automatically adjusted according to the production rhythm and working condition changes through a self-learning program, key dust accumulation parts of the heat exchanger are blown, dust cannot be accumulated in the heat exchanger, the overhaul period of the heat exchanger is effectively prolonged, the production cost is reduced, and the heat exchange efficiency of the heat exchanger is guaranteed. The service life of the heat exchanger is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchanger ash cleaning, and particularly to an on-line ash cleaning method for a tubular heat exchanger. Background Art

[0002] A tubular heat exchanger is a shell-and-tube heat exchanger with the wall surface of the tube bundle enclosed in a shell, which can realize heat exchange between a cold fluid and a hot fluid. It is widely used in the fields of petrochemical industry, electric power metallurgy, refrigeration and cryogenics, energy power, aerospace, etc. The application scenarios are often in harsh working conditions, mostly high-temperature, dusty, and strongly corrosive occasions, which directly affect its service life and operating efficiency. It is difficult to clean the ash of the tubular heat exchanger because the tubular heat exchanger is generally of a welded structure and many parts in the middle cannot be cleaned. At present, for the tubular heat exchangers used under conditions of not very high temperature, the common ash cleaning methods are generally off-line cleaning by means of vibration, acoustic wave and high-pressure air gun blowing during maintenance. For the tubular heat exchangers working in high-temperature and dusty occasions, the above methods are difficult to play an effective cleaning role, and generally only the tubular heat exchanger can be replaced.

[0003] The Chinese utility model patent with the application number CN201520926242.3 discloses an "ash cleaning device for a tubular heat exchanger" to realize the ash cleaning of the part of the heat exchange tube between adjacent two heat exchange tubes, including a plate-shaped ash cleaning knife and a chain. The height of the plate-shaped ash cleaning knife is less than the distance between adjacent two rows of heat exchange tubes, and the plate-shaped ash cleaning knife can batch clean the ash on the surface of the plate heat exchanger; the width of the chain is less than the distance between adjacent two heat exchange tubes, and the chain collides with the heat exchange tubes to remove the ash adhering to the part of the heat exchange tube between adjacent two heat exchange tubes. When using this method, the tubular heat exchanger must be taken offline for off-line cleaning, and the cleaning efficiency is low and the time consumption is long.

[0004] The Chinese utility model patent with the application number CN201420621865.5 discloses an "ash cleaning device for a finned tube heat exchanger", including: a pair of tracks parallel to each other; a fixed frame with the pair of tracks arranged thereon; a moving frame provided with at least a pair of wheels and movably arranged on the tracks through the wheels, wherein one of the wheels is a power output wheel; a brush shaft rotatably arranged on the moving frame and arranged parallel to the tracks; a cleaning brush arranged on the brush shaft; a driving mechanism connected to the moving frame to drive the moving frame to move along the tracks; and a steering transmission mechanism arranged between the power output wheel and the brush shaft to drive the brush shaft to rotate when the power output wheel rolls along the tracks. The cleaning brush removes the ash adhering to the finned tube through reciprocating motion and its own rotation. The device has a relatively complex structure and can only realize off-line cleaning.

[0005] The Chinese utility model patent with the application number CN202321704164.3 discloses a "dust cleaning device for a micro-negative pressure gas heat exchanger", which is used to solve the problems of dead corners in dust cleaning of heat exchange tubes of micro-negative pressure gas heat exchangers and inconvenient disassembly of sealing flanges. It includes the rear smoke box of the gas heat exchanger. One side of the rear smoke box of the gas heat exchanger is provided with a rear smoke box tube sheet, and a number of dust cleaning devices are welded on one side of the rear smoke box tube sheet. The dust cleaning device includes: a threaded tube, the threaded tube is welded on one side of the rear smoke box tube sheet, a quick-opening valve cover is threadedly connected to one end of the threaded tube, a sealing gasket is arranged between the threaded tube and the quick-opening valve cover, and a nut is welded on one side of the quick-opening valve cover. This device is an off-line dust cleaning device and has a relatively narrow application field. Summary of the Invention

[0006] The present invention provides an on-line dust cleaning method for a tubular heat exchanger. Side spray holes are provided on one side of the flue where the tubular heat exchanger is installed, and a movable high-pressure gas spray gun is used for on-line dust cleaning. A self-learning program can be used to automatically adjust the spray position, spray time and spray frequency according to the production rhythm and working conditions changes, and spray on the key dust accumulation parts of the heat exchanger, so that dust cannot accumulate in the heat exchanger, effectively extending the overhaul period of the heat exchanger, reducing production costs, ensuring the heat exchange efficiency of the heat exchanger, and extending the service life of the heat exchanger.

[0007] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0008] An on-line dust cleaning method for a tubular heat exchanger includes the following processes:

[0009] 1) The tubular heat exchanger is arranged in the flue. A plurality of side spray holes are provided on one side of the flue corresponding to the installation position of the tubular heat exchanger. The side spray holes are arranged in one-to-one correspondence with the heat exchange tubes of the tubular heat exchanger and are arranged longitudinally along the heat exchange tubes. The side spray holes are composed of a plurality of spray holes arranged at intervals, and each spray hole is closed by a baffle arranged in the flue.

[0010] 2) Use a high-pressure gas spray gun to perform on-line dust cleaning on the tubular heat exchanger. The high-pressure gas spray gun is arranged on the spray gun slide rail and can move along the horizontal and vertical directions. During dust cleaning, the high-pressure gas ejected by the high-pressure gas spray gun blows open the baffle closing the spray hole and performs high-pressure spraying on the heat exchange tube.

[0011] 3) A switch control valve is arranged on the high-pressure gas spray gun. The switch control valve is controlled by the control system of the functional unit where the tubular heat exchanger is located. The control system is provided with a self-learning model to automatically control the moving position, opening time and stopping time of the high-pressure gas spray gun according to the working conditions of the tubular heat exchanger.

[0012] The side spray holes are arranged longitudinally along the heat exchange tubes, and the spray holes are closed by corresponding baffles; the upper end of the baffle is rotatably connected to an ear seat provided on the inner wall of the flue through a rotating shaft, and the area of the baffle is larger than the area of the spray holes.

[0013] The baffle is composed of a baffle body and a sealing rubber ring; the baffle body is made of a high-temperature resistant steel plate, and a sealing rubber ring is provided on the side of the baffle in contact with the inner wall of the flue, and the sealing rubber ring is a high-temperature resistant rubber ring.

[0014] The high-pressure gas spray gun is composed of a vertical telescopic section, a horizontal telescopic section, a rotary joint, a spray nozzle and a switch control valve; one end of the vertical telescopic section is connected to a high-pressure gas source through a high-pressure gas delivery hose, and the other end of the vertical telescopic section is connected to one end of the horizontal telescopic section; both the vertical telescopic section and the horizontal telescopic section are telescopic structures; the other end of the horizontal telescopic section is connected to the spray nozzle through a rotary joint; the switch control valve is arranged on the horizontal telescopic section close to the rotary joint.

[0015] The spray gun slide rail includes a vertical slide rail and a horizontal slide rail. The high-pressure gas spray gun is provided with rollers and a roller driving device, and the high-pressure gas spray gun moves along the spray gun slide rail under the drive of the roller driving device; the control end of the roller driving device is connected to a control system, and the moving position of the high-pressure gas spray gun is controlled by the control system.

[0016] The blowing pressure of the high-pressure gas spray gun is 1 - 4 bar, and the blowing gas flow rate is 0.1 - 0.3 Nm 3 / min.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] Side spray holes are provided on one side of the flue where the tubular heat exchanger is installed, and a movable high-pressure gas spray gun is used for on-line dust cleaning; the self-learning program can automatically adjust the spraying position, spraying time and spraying frequency according to the production rhythm and working condition changes, and spray on the key dust accumulation parts of the heat exchanger, so that dust cannot accumulate in the heat exchanger, effectively extending the overhaul period of the heat exchanger, reducing the production cost, ensuring the heat exchange efficiency of the heat exchanger, and prolonging the service life of the heat exchanger. Brief Description of the Drawings

[0019] Figure 1 is a schematic diagram of a method for on-line dust cleaning of a tubular heat exchanger according to the present invention.

[0020] Figure 2 is a schematic diagram of the side spray holes on the flue according to the present invention.

[0021] Figure 3 is a schematic structural diagram of the high-pressure gas spray gun according to the present invention.

[0022] In the figure: 1. Tube heat exchanger; 2. Flue; 3. Side spray holes; 31. Spray holes; 4. High-pressure gas spray gun; 41. Vertical telescopic section; 42. Horizontal telescopic section; 43. Rotary joint; 44. Spray nozzle; 45. Switch control valve; 5. Spray gun slide rail; 6. Baffle Detailed implementation manners

[0023] The following further describes the detailed implementation manners of the present invention with reference to the accompanying drawings:

[0024] As Figures 1 - 3 shown, a method for on-line ash cleaning of a tube heat exchanger according to the present invention includes the following processes:

[0025] 1) The tube heat exchanger 1 is arranged in the flue 2. A plurality of side spray holes 3 are arranged on one side of the flue 2 corresponding to the installation position of the tube heat exchanger 1. The side spray holes 3 are arranged in one-to-one correspondence with the heat exchange tubes of the tube heat exchanger 1 and are arranged longitudinally along the heat exchange tubes; the side spray holes 3 are composed of a plurality of spray holes 31 arranged at intervals, and each spray hole 31 is closed by a baffle 6 arranged in the flue 2;

[0026] 2) Use a high-pressure gas spray gun 4 to perform on-line ash cleaning on the tube heat exchanger 1; the high-pressure gas spray gun 4 is arranged on the spray gun slide rail 5 and can move in the horizontal and vertical directions; during ash cleaning, the high-pressure gas sprayed by the high-pressure gas spray gun 4 blows open the baffle 6 closing the spray hole 31 and performs high-pressure spraying on the heat exchange tubes;

[0027] 3) A switch control valve 45 is arranged on the high-pressure gas spray gun 4. The switch control valve 45 is controlled by the control system of the functional unit where the tube heat exchanger is located. The control system is provided with a self-learning model to automatically control the moving position, opening time and stopping time of the high-pressure gas spray gun 4 according to the working conditions of the tube heat exchanger.

[0028] The side spray holes 3 are arranged longitudinally along the heat exchange tubes, and the spray holes 31 are closed by corresponding baffles 6; the upper end of the baffle 6 is rotatably connected to an ear seat arranged on the inner wall of the flue 2 through a rotating shaft, and the area of the baffle 6 is larger than the area of the spray hole 31.

[0029] The baffle 6 is composed of a baffle body and a sealing rubber ring; the baffle body is made of a high-temperature resistant steel plate, and a sealing rubber ring is arranged on the side of the baffle 6 in contact with the inner wall of the flue 2, and the sealing rubber ring is a high-temperature resistant rubber ring.

[0030] The high-pressure gas spray gun 4 is composed of a vertical telescopic section 41, a horizontal telescopic section 42, a rotary joint 43, a nozzle 44 and a switch control valve 45. One end of the vertical telescopic section 41 is connected to a high-pressure gas source through a high-pressure gas delivery hose, and the other end of the vertical telescopic section 41 is connected to one end of the horizontal telescopic section 42. Both the vertical telescopic section 41 and the horizontal telescopic section 42 are telescopic structures. The other end of the horizontal telescopic section 42 is connected to the nozzle 44 through the rotary joint 43. The switch control valve 45 is arranged on the horizontal telescopic section 42 close to the rotary joint 43.

[0031] The spray gun slide rail 5 includes a vertical slide rail and a horizontal slide rail. The high-pressure gas spray gun 4 is provided with rollers and a roller driving device. Driven by the roller driving device, the high-pressure gas spray gun 4 moves along the spray gun slide rail 5. The control end of the roller driving device is connected to a control system, and the movement position of the high-pressure gas spray gun 4 is controlled by the control system.

[0032] The blowing pressure of the high-pressure gas spray gun is 1 - 4 bar, and the blowing gas flow rate is 0.1 - 0.3 Nm 3 / min.

[0033] For the method for online soot cleaning of a tubular heat exchanger according to the present invention, the schematic diagram of its working principle is as Figure 1 shown. A side spray hole 3 is arranged on one side of the flue 2 where the tubular heat exchanger 1 is installed, and a movable high-pressure gas spray gun 4 is used for online soot cleaning. During the operation of the production system, the soot cleaning operation of the tubular heat exchanger 1 can be switched between a manual mode and an automatic mode. The manual mode is that an operator selects the blowing position and blowing time of the high-pressure gas spray gun 4. The automatic mode is that the control system automatically controls the blowing position, blowing time, and blowing interval of the high-pressure gas spray gun 4, and can further be automatically controlled according to different production conditions through a self-learning algorithm to perform online soot cleaning on the tubular heat exchanger 1.

[0034] The structure of the side spray hole 3 is as Figure 2 shown. A side spray hole 3 is opened on the side wall of one side of the flue 2 corresponding to the installation position of the tubular heat exchange tube 1. The length and width of the side spray hole 3 are the same as those of the corresponding heat exchange tube. The side spray hole 3 is composed of a plurality of spray holes 31 arranged at intervals. A baffle 6 is covered inside each spray hole 31. The area of the baffle 6 is larger than the area of the spray hole 31. The baffle 6 is rotatably arranged inside the spray hole 31. When the soot cleaning operation is not performed, the baffle 6 can completely cover the spray hole 31 to prevent flue gas leakage.

[0035] The structure of the high-pressure gas spray gun 4 according to the present invention is as Figure 3As shown, a switch control valve 45 is provided on the high-pressure gas spray gun 4 to control the opening time and gas flow rate of the high-pressure gas spray gun 4. The gas source of the high-pressure gas spray gun 4 can be high-pressure air or high-pressure inert gas. The vertical telescopic section 41 and the horizontal telescopic section 42 of the high-pressure gas spray gun 4 can extend during use and retract when not in use, facilitating the movement and maintenance of the high-pressure gas spray gun 4. The rotary joint 43 of the high-pressure gas spray gun 4 is used to adjust the angle of the nozzle 44, increasing the spraying area and enabling effective dust cleaning of all parts of the heat exchange tube. High-pressure gas is ejected from the nozzle 44 of the high-pressure gas spray gun 4.

[0036] Three groups of high-pressure gas spray guns 4 can be set. One group is the main spray gun, and the other two groups are spare spray guns. The three groups of high-pressure gas spray guns 4 can spray simultaneously, or the main spray gun can be used alone for spraying. When the main spray gun is damaged, the spare spray guns are used. The high-pressure gas spray gun 4 can move along the spray gun slide rail 5 through pulleys, which is convenient for movement and replacement.

[0037] The method for online dust cleaning of a tubular heat exchanger according to the present invention solves the problems of the existing tubular heat exchanger being unable to achieve online dust cleaning, complex dust cleaning operations, and incomplete cleaning. By using a high-pressure gas spray gun, different positions of the tubular heat exchanger can be sprayed to prevent dust accumulation. By setting a self-learning program, the spraying time, spraying position, and spraying frequency can be automatically adjusted according to different working conditions, which is an energy-saving, efficient, and simple online dust cleaning method for heat exchangers.

[0038] Adjust the working parameters of the high-pressure gas spray gun according to the working pressure of the shell-and-tube heat exchanger.

[0039] The above is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes should be covered within the protection scope of the present invention.

Claims

1. A method for online soot cleaning of a tubular heat exchanger, characterized in that, It includes the following processes: 1) The tubular heat exchanger is arranged in the flue gas duct. A plurality of side spray holes are arranged on one side of the flue gas duct corresponding to the installation position of the tubular heat exchanger. The side spray holes are arranged in one-to-one correspondence with the heat exchange tubes of the tubular heat exchanger and are arranged longitudinally along the heat exchange tubes. The side spray holes are composed of a plurality of spray holes arranged at intervals, and each spray hole is closed by a baffle arranged in the flue gas duct. 2) An online dust cleaning is carried out on the tubular heat exchanger by using a high-pressure gas spray gun. The high-pressure gas spray gun is arranged on the spray gun slide rail and can move in the horizontal and vertical directions. During dust cleaning, the high-pressure gas sprayed by the high-pressure gas spray gun blows open the baffle closing the spray hole and performs high-pressure spraying on the heat exchange tubes. 3) A switch control valve is arranged on the high-pressure gas spray gun. The switch control valve is controlled by the control system of the functional unit where the tubular heat exchanger is located. The control system is provided with a self-learning model to automatically control the moving position, opening time and stopping time of the high-pressure gas spray gun according to the working conditions of the tubular heat exchanger.

2. A method for online ash cleaning of a tubular heat exchanger according to claim 1, characterized in that, The side spray holes are arranged longitudinally along the heat exchange tubes, and the spray holes are closed by corresponding baffles. The upper end of the baffle is rotatably connected to an ear seat arranged on the inner wall of the flue gas duct through a rotating shaft, and the area of the baffle is larger than the area of the spray hole.

3. A method for online soot cleaning of a tubular heat exchanger according to claim 1, characterized in that The baffle is composed of a baffle body and a sealing rubber ring. The baffle body is made of a high-temperature resistant steel plate, and a sealing rubber ring is arranged on the side of the baffle in contact with the inner wall of the flue gas duct. The sealing rubber ring adopts a high-temperature resistant rubber ring.

4. A method for online soot cleaning of a tubular heat exchanger according to claim 1, characterized in that, The high-pressure gas spray gun is composed of a vertical telescopic section, a horizontal telescopic section, a rotary joint, a spray port and a switch control valve. One end of the vertical telescopic section is connected to a high-pressure gas source through a high-pressure gas delivery hose, and the other end of the vertical telescopic section is connected to one end of the horizontal telescopic section. Both the vertical telescopic section and the horizontal telescopic section are telescopic structures. The other end of the horizontal telescopic section is connected to the spray port through a rotary joint. The switch control valve is arranged on the horizontal telescopic section close to the rotary joint.

5. A method for online ash cleaning of a tubular heat exchanger according to claim 1, characterized in that, The spray gun slide rail includes a vertical slide rail and a horizontal slide rail. The high-pressure gas spray gun is provided with rollers and a roller driving device. Driven by the roller driving device, the high-pressure gas spray gun moves along the spray gun slide rail. The control end of the roller driving device is connected to the control system, and the moving position of the high-pressure gas spray gun is controlled by the control system.

6. A method for online soot cleaning of a tubular heat exchanger according to claim 1, characterized in that, The injection pressure of the high-pressure gas spray gun is 1 - 4 bar, and the injection gas flow rate is 0.1 - 0.3 Nm 3 / min.

Images