Method for reducing smoking of flame tube of existing engine and flame tube structure thereof

Abstract

The invention discloses a method for reducing smoking of a flame tube of an existing engine and a flame tube structure of the flame tube. On the basis that an inner ring structure and an outer ring structure of the flame tube do not need to be changed, an air inlet hole is formed in the head of the flame tube, and meanwhile a mixing hole is blocked; according to the improved flame tube, fuel oil is combusted at the head, the atomization performance of a working nozzle and the oil-gas mixing effect are good, combustion of fuel oil in the flame tube is facilitated, pollutant emission is reduced, the requirement that the exhaust Ringelman smoke blackness is smaller than the first level is met, meanwhile, it is guaranteed that the temperature of an outlet of a flame tube combustion chamber can meet the design requirement, and the service life is prolonged. When the method is used for transforming the flame tube, the basic structure of the flame tube is reserved, the flame tube does not need to be redesigned, a large amount of test verification is avoided, the test period is shortened, and the development cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of flame tube processing technology, and more specifically, to a method for reducing smoke emission from existing engine flame tubes and the structure of the flame tube thereof. Background Technology

[0002] During engine operation, insufficient air intake at the combustion chamber head often results in visible black smoke from the flame tube, failing to meet user requirements. This necessitates improvements to the combustion chamber components to meet the engine exhaust Ringelmann smoke blackness requirement of less than level 1. Generally, this requires a complete redesign of the flame tube, particularly the head structure. Such improvements necessitate extensive testing and verification, a lengthy process, and replacement of all in-service flame tubes, leading to high costs.

[0003] like Figure 1 As shown, the existing flame tube structure includes a flame tube head 1, an inner ring 2, and an outer ring 3. The flame tube head 1 has a main combustion port 4, which allows air to enter and ensures stable combustion of fuel and air. Mixing ports 5 are provided at the third inner and outer rings of the flame tube. The main function of the mixing ports 5 is to cool the combustion chamber outlet temperature. At the same time, the position, size, and number of mixing ports will also affect the air intake of the main combustion port. Therefore, when improving the existing flame tube structure, how to ensure sufficient air intake at the flame tube head without producing black smoke, and at the same time ensure that the combustion chamber outlet temperature meets the design requirements, is the current design challenge.

[0004] Utility model CN210345531U discloses an annular combustion chamber, including an outer combustion chamber and an inner combustion chamber. The outer combustion chamber is sleeved outside the front end of the inner combustion chamber. The front end face of the outer combustion chamber has a plurality of air inlet holes for supplying air into the outer combustion chamber. The inner and outer side walls of the outer combustion chamber have a plurality of air inlet holes. The side wall of the inner combustion chamber has an air inlet through hole that communicates with the air inlet holes located on the inner side wall of the outer combustion chamber. By opening an air inlet on the front end face of the outer cylinder of the combustion chamber, the air intake at the head of the combustion chamber can be increased, the fuel-air equivalence ratio at the head of the combustion chamber can be improved, and the position of the main combustion zone can be advanced. At the same time, the air intake direction of the air inlet is consistent with the direction of the recirculation airflow inside the combustion chamber, which can also enhance the swirling intensity of the recirculation zone, making the combustion flame more stable, the fuel-air mixing better, and the combustion more complete, thereby improving the working efficiency of the combustion chamber. This utility model discloses a new combustion chamber structure. Since the existing engine structure is fixed, it is impossible to improve the existing engine structure according to the combustion chamber structure of this utility model to solve the black smoke problem of the existing structure. Summary of the Invention

[0005] To address the problem of visible black smoke in existing engines during operation, this invention provides a method for reducing smoke from the flame tube of existing engines and its flame tube structure.

[0006] The technical solution of this invention is: A method for reducing smoke emission from an existing engine flame tube, wherein the flame tube structure includes a flame tube head, an inner flame tube ring, and an outer flame tube ring. The inner and outer flame tube rings are connected to the flame tube head via a weld. A fuel nozzle is installed on the flame tube head, and multiple main combustion holes are formed on the wall of the flame tube head. Mixing holes are also formed on the walls of the inner and outer flame tube rings. The method includes the following steps: S1: An air inlet is opened on the head wall of the flame tube. The air inlet is located in the area between 30mm from the front end of the fuel nozzle and the main combustion hole, and is distributed along the circumference of the fuel nozzle. There are two rows of air inlets, with 13 to 20 air inlets in each row. The diameter of a single air inlet is 1 to 3mm, and the entire flame tube has 260 to 400 air inlets. S2: Use patch material to seal the original mixing hole, and the total area of ​​the sealing is 8 times the total area of ​​the air inlet hole opened in step S1; S3: Conduct an installation test on the modified flame tube.

[0007] Furthermore, the air inlet is oriented perpendicular to the flame tube wall.

[0008] Furthermore, the air intake is circular.

[0009] Furthermore, the spacing between the two rows of holes in step S1 is 6~7mm.

[0010] Furthermore, the patch material has the same material and thickness as the flame tube ring.

[0011] Furthermore, in step S1, the air inlet hole is processed using laser drilling.

[0012] Furthermore, in step S2, argon arc welding is used to seal the original mixing holes.

[0013] Furthermore, the tests conducted in step S3 include exhaust Ringelmann smoke opacity detection and flame tube outlet temperature detection.

[0014] Furthermore, the original mixing holes are located at the third inner and outer rings of the flame tube, and are evenly distributed in two rows.

[0015] A flame tube structure for reducing smoke emission from an engine flame tube, the flame tube structure being processed using the method described above.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a method for reducing smoke from the existing engine burner tube. This method, without changing the existing inner and outer ring structure of the burner tube, improves the combustion performance of the fuel nozzle at the head of the burner tube by opening an air inlet and sealing the mixing hole. The improved burner tube has better atomization performance and fuel-air mixing effect, which is beneficial to the combustion of fuel in the burner tube, reduces pollution emissions, and meets the requirement of exhaust Ringelmann smoke opacity of less than level 1. At the same time, it ensures that the outlet temperature of the burner tube combustion chamber meets the design requirements.

[0017] Using this method to modify the flame tube retains its basic structure, eliminating the need for redesign and avoiding extensive testing, thus shortening the testing cycle and reducing development costs. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the flame tube structure of this application; Figure 2 This is a schematic diagram of the cross-sectional structure of the flame tube in this application; Figure 3 This is a partially enlarged schematic diagram of the location of the air inlet of the flame tube in this application; Among them: 1. Flame tube head; 2. Flame tube inner ring; 3. Flame tube outer ring; 4. Mixing hole; 5. Main combustion hole; 6. Fuel nozzle; 61. Fuel nozzle front end; 7. Air inlet. Detailed Implementation

[0019] To clearly illustrate the technical features of the present invention, the invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the invention. However, the invention can also be implemented in other ways different from those described herein; therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below. Furthermore, in the description of the invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. In this invention, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "fixed," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. In this invention, unless otherwise explicitly specified and limited, "on" or "below" a second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

[0020] Example 1 Please see Figures 1 to 3 This embodiment provides a method for reducing smoke from the existing engine flame tube. This method addresses the problem of visible black smoke during engine operation by modifying the existing flame tube structure. Figure 1As shown, the flame tube structure includes a flame tube head 1, an inner flame tube ring 2, and an outer flame tube ring 3. The inner flame tube ring 2 and the outer flame tube ring 3 are connected to the flame tube head 1 by a weld. Ten sets of fuel nozzles 6 are evenly arranged on the flame tube head 1. Multiple main combustion holes 4 are also provided on the wall of the flame tube head 1. The main combustion holes 4 allow air intake to ensure stable combustion of fuel and air. Mixing holes 5 are also provided on the walls of the inner flame tube ring 2 and the outer flame tube ring 3. The steps of the method include: S1: An air inlet 7 is opened on the wall of the flame tube head 1. The air inlet 7 is located 40mm away from the fuel nozzle and is distributed around the fuel nozzle 6. There are two rows of air inlets 7. The direction of the air inlets is perpendicular to the flame tube wall. The air inlets are circular. There are 13 air inlets 7 in each row. The distance between the two rows of holes is 7mm. The diameter of a single air inlet 7 is 3mm. There are 260 air inlets in the entire flame tube. The air inlets 7 are processed by laser drilling.

[0021] like Figure 3 As shown, the air intake 7 is located in front of the main combustion port 4. The main combustion port 4 is the original design of the flame tube. In order to ensure stable combustion of the airflow in the main combustion zone, the air intake 7 can only be added in front of the main combustion port 4. At the same time, considering that the optimal atomization area of ​​the fuel nozzle is located at 30mm from the front end 61 of the fuel nozzle, the air intake 7 is designed in the area between 30mm from the front end of the fuel nozzle and the main combustion port 4. In this embodiment, the position is set at 40mm from the fuel nozzle. This position can ensure that the air entering from the air intake 7 further mixes and burns the fuel.

[0022] S2: Use patch material to seal the original mixing hole 5. The patch material has the same material and thickness as the flame tube ring and is processed by argon arc welding. The total area of ​​the sealing is 8 times the total area of ​​the air inlet hole 7 opened in step S1. When sealing the original mixing hole 5, it is necessary to ensure the uniformity of the outlet temperature field. The original mixing hole 5 is located at the third inner and outer rings of the flame tube and is evenly distributed in two rows. According to the relationship between the fuel quantity and the head air volume, the combustion at the head needs to achieve lean combustion to reduce black smoke. The initial fuel-air equivalence ratio at the head is set to 0.85 (less than 1 is lean combustion). Based on the fuel quantity of a single nozzle, the required air volume at the head can be calculated. Then, based on the head area / total area (the head area is the sum of the areas of the main combustion hole and the air intake hole, and the total area is the sum of the areas of the mixing hole, the air intake hole, and the main combustion hole) and the mixing hole area / total area, the area of ​​one air intake hole and the area to be sealed are initially set. After multiple iterations, it is found that the area that needs to be increased at the head (i.e., the area of ​​the air intake hole) and the area that needs to be reduced by the mixing hole are approximately 8 times.

[0023] S3: Conduct an installation test on the modified flame tube.

[0024] The modified flame tube from step S3 was subjected to an installation test. The test items included exhaust Ringelmann smoke opacity detection and flame tube outlet temperature detection. After testing, the processing method with a diameter of 3mm, a quantity of 13×2, and a total of 260 holes showed the best results. After modification, the air intake volume at the flame tube head increased from 6.25% to 20.5%, and the air intake volume of the mixing hole was adjusted from 45% to 28.7%. The results show that the modified engine meets the requirement of exhaust Ringelmann smoke opacity of less than level 1, and the flame tube outlet temperature also meets the design requirements.

[0025] Example 2 Please see Figures 1 to 3 This embodiment provides a method for reducing smoke from the existing engine flame tube. This method addresses the problem of visible black smoke during engine operation by modifying the existing flame tube structure. Figure 1 As shown, the flame tube structure includes a flame tube head 1, an inner flame tube ring 2, and an outer flame tube ring 3. The inner flame tube ring 2 and the outer flame tube ring 3 are connected to the flame tube head 1 by a weld. Ten sets of fuel nozzles 6 are evenly arranged on the flame tube head 1. Multiple main combustion holes 4 are also provided on the wall of the flame tube head 1. The main combustion holes 4 allow air intake to ensure stable combustion of fuel and air. Mixing holes 5 are also provided on the walls of the inner flame tube ring 2 and the outer flame tube ring 3. The steps of the method include: S1: An air inlet 7 is opened on the head wall of the flame tube. The air inlet 7 is located 50mm away from the fuel nozzle and is distributed around the fuel nozzle 6. There are two rows of air inlets 7. The direction of the air inlets 7 is perpendicular to the flame tube wall. The air inlets 7 are circular. There are 20 air inlets in each row. The distance between the two rows of holes is 6mm. The diameter of a single air inlet is 1mm. There are 400 air inlets in the entire flame tube. The air inlets 7 are processed by laser drilling.

[0026] like Figure 3 As shown, the air intake 7 is located in front of the main combustion port 4. The main combustion port 5 is the original design of the flame tube. In order to ensure stable combustion of the airflow in the main combustion zone, the air intake 7 can only be added in front of the main combustion port. At the same time, considering that the optimal atomization area of ​​the fuel nozzle is located at 30mm from the front end 61 of the fuel nozzle, the air intake 7 is designed in the area between 30mm from the front end of the fuel nozzle and the main combustion port 5. In this embodiment, the position is set at 50mm from the fuel nozzle. This position can ensure that the air entering from the air intake port further mixes and burns the fuel. S2: Use patch material to seal the original mixing hole. The patch material has the same material and thickness as the flame tube ring and is processed by argon arc welding. The total area of ​​the sealing is 8 times the total area of ​​the air inlet hole opened in step S1.

[0027] S3: The modified flame tube was tested on the machine. The improved flame tube has better atomization performance and oil-gas mixing effect at the fuel working nozzle at the head, which is conducive to the combustion of fuel in the flame tube, reduces pollution emissions, and eliminates black smoke.

[0028] Example 3 Please see Figures 1 to 3 This embodiment provides a method for reducing smoke from the existing engine flame tube. This method addresses the problem of visible black smoke during engine operation by modifying the existing flame tube structure. Figure 1 As shown, the flame tube structure includes a flame tube head 1, an inner flame tube ring 2, and an outer flame tube ring 3. The inner flame tube ring 2 and the outer flame tube ring 3 are connected to the flame tube head 1 by a weld. Ten sets of fuel nozzles 6 are evenly arranged on the flame tube head 1. Multiple main combustion holes 4 are also provided on the wall of the flame tube head 1. The main combustion holes 4 allow air intake to ensure stable combustion of fuel and air. Mixing holes 5 are also provided on the walls of the inner flame tube ring 2 and the outer flame tube ring 3. The steps of the method include: S1: An air inlet 7 is opened on the wall of the flame tube head 1. The air inlet 7 is located 60mm away from the fuel nozzle and is distributed around the fuel nozzle 6. There are two rows of air inlets 7. The direction of the air inlets 7 is perpendicular to the flame tube wall. The air inlets 7 are circular. There are 17 air inlets in each row. The distance between the two rows of holes is 6mm. The diameter of a single air inlet 7 is 2mm. There are 340 air inlets in the entire flame tube. The air inlets 7 are processed by laser drilling.

[0029] like Figure 3 As shown, the air intake 7 is located in front of the main combustion port 4. The main combustion port 5 is the original design of the flame tube. In order to ensure stable combustion of the airflow in the main combustion zone, the air intake 7 can only be added in front of the main combustion port 4. At the same time, considering that the optimal atomization area of ​​the fuel nozzle is located at 60mm from the front end 61 of the fuel nozzle, the air intake 7 is designed in the area between 60mm from the front end of the fuel nozzle and the main combustion port. In this embodiment, the position is set at 60mm from the fuel nozzle. This position can ensure that the air entering from the air intake port can further mix and burn the fuel. S2: Use patch material to seal the original mixing hole. The patch material has the same material and thickness as the flame tube ring and is processed by argon arc welding. The total area of ​​the sealing is 8 times the total area of ​​the air inlet hole opened in step S1. S3: The modified flame tube was tested on the machine. The improved flame tube has better atomization performance and oil-gas mixing effect at the fuel working nozzle at the head, which is conducive to the combustion of fuel in the flame tube, reduces pollution emissions, and eliminates black smoke.

[0030] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for reducing smoke emission from an existing engine flame tube, wherein the flame tube structure includes a flame tube head, an inner flame tube ring, and an outer flame tube ring, the inner and outer flame tube rings being connected to the flame tube head via a weld, the flame tube head being equipped with a fuel nozzle, and multiple main combustion holes being formed on the wall of the flame tube head; mixing holes are also formed on the walls of the inner and outer flame tube rings, characterized in that... The method includes the following steps: S1: An air inlet is opened on the head wall of the flame tube. The air inlet is located in the area between 30mm from the front end of the fuel nozzle and the main combustion hole, and is distributed along the circumference of the fuel nozzle. There are two rows of air inlets, with 13 to 20 air inlets in each row. The diameter of a single air inlet is 1 to 3mm, and the entire flame tube has 260 to 400 air inlets. S2: Use patch material to seal the original mixing hole, and the total area of ​​the sealing is 8 times the total area of ​​the air inlet hole opened in step S1; S3: Conduct an installation test on the modified flame tube.

2. The method for reducing smoke from the flame tube of an existing engine according to claim 1, characterized in that, The air inlet is perpendicular to the wall of the flame tube.

3. The method for reducing smoke from the flame tube of an existing engine according to claim 1, characterized in that, The air inlet is circular.

4. The method for reducing smoke from existing engines according to claim 1, characterized in that, The spacing between the two rows of holes in step S1 is 6~7mm.

5. The method for reducing smoke from the flame tube of an existing engine according to claim 1, characterized in that, The patch material is the same as the flame tube ring material and thickness.

6. The method for reducing smoke from the flame tube of an existing engine according to claim 1, characterized in that, In step S1, the air inlet is processed using laser drilling.

7. The method for reducing smoke from the flame tube of an existing engine according to claim 1, characterized in that, In step S2, argon arc welding is used to seal the original mixed holes.

8. The method for reducing smoke from the flame tube of an existing engine according to claim 1, characterized in that, The tests conducted in step S3 include exhaust Ringelmann smoke opacity detection and flame tube outlet temperature detection.

9. A method for reducing smoke from the flame tube of an existing engine according to claim 1, characterized in that, The original mixing holes are located at the third inner and outer rings of the flame tube, and are evenly distributed in two rows.

10. A flame tube structure for reducing smoke emission from an engine flame tube, characterized in that, The flame tube structure is obtained by processing using the method described in any one of claims 1 to 9.

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