Mechanical vibration stress optimization method for waste heat boiler

Abstract

The invention provides a mechanical vibration stress optimization method of a waste heat boiler, a rapping mechanism is adopted for hammering an impact rod of a dust removal mechanism, the rapping mechanism comprises a connecting rod, a rapping rod, a rapping hammer and a lifting lug, one end of the connecting rod is detachably connected with a driving shaft, the other end of the connecting rod is provided with a hollow structure, the hollow structure is hinged to the rapping rod, and the rapping hammer is connected with the lifting lug. The end, away from the connecting rod, of the rapping rod is hinged to a rapping hammer through a lifting lug, and the rapping hammer is used for hammering an impact rod of the ash removal mechanism. According to the mechanical vibration stress optimization method for the waste heat boiler, the problem that large bending stress is likely to be generated at the connecting position due to the fact that the vibration stress design of an ash removal device in the related technology is unreasonable and the stress at the connecting position is uneven is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of waste heat boilers, and in particular relates to a method for optimizing the mechanical vibration force of a waste heat boiler. Background Art

[0002] The cleaning device of the waste heat boiler is very important in industrial applications, especially when dealing with waste gas with a large dust content. The mechanical vibration device is the main cleaning equipment, which removes the accumulated dust on the heating surface of the boiler through vibration. Each layer of the heating surface is usually equipped with a set of mechanical vibration devices. The original design of these devices is to use a vibration motor to drive multiple mechanical vibration mechanisms to remove the accumulated dust from the heating surface through a reasonable vibration frequency and force, thereby improving the thermal efficiency of the boiler. Due to its low power consumption, low cost and good cleaning effect, mechanical vibration devices are widely used in the industrial field.

[0003] However, in actual engineering applications, the design and use of mechanical vibration devices have also exposed some problems. The most important problem occurs at the connection between the rapping rod and the rapping hammer. Due to the unreasonable design of the rapping force of the cleaning device in the related technology, the force at the connection is uneven, which leads to large bending stress at this location. In long-term operation, this stress concentration will cause fatigue fracture, and then cause the rapping rod to break. This not only affects the normal operation of the equipment, but also increases the maintenance cost. Summary of the invention

[0004] In view of this, the present invention aims to solve one of the related technical problems at least to a certain extent.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] A method for optimizing the mechanical vibration force of a waste heat boiler, using a rapping mechanism to hammer the impact rod of a cleaning mechanism, the rapping mechanism comprising a connecting rod, a rapping rod, a rapping hammer and a lifting lug, one end of the connecting rod is detachably connected to a driving shaft, the other end of the connecting rod is provided with a hollow structure, the hollow structure is hinged to the rapping rod, the end of the rapping rod away from the connecting rod is hinged to the rapping hammer through the lifting lug, the rapping hammer is used to hammer the impact rod of the cleaning mechanism, and the force of the rapping mechanism is further optimized, and the specific steps are:

[0007] Step 1: The center of gravity of the rapping hammer and the axis of the impact rod of the cleaning mechanism are located in the same straight line;

[0008] Step 2: The distance between the hinge points at both ends of the rapping rod is 150mm-250mm, and the distance between the hinge points at both ends of the connecting rod is 130mm-170mm;

[0009] Step 3: The diameter of the rapping hammer is 100mm-120mm.

[0010] Furthermore, the rapping rod includes an articulated sleeve, a connecting plate and an articulated frame. The top of the articulated frame is connected to the articulated sleeve through the connecting plate. The articulated sleeve is articulated to the connecting rod. The articulated frame is articulated to the lifting ear. A counterweight hole is provided in the middle of the connecting plate.

[0011] Furthermore, the width ratio of the side of the hinge sleeve to the side of the hinge frame is 1:1.25-1:1.35.

[0012] Furthermore, the ratio of the width to the length of the rapping rod is 1:5.5-1:7.5, and the thickness of the rapping rod is not less than 8 mm.

[0013] Furthermore, the mass of the rapping hammer is 4.5kg-6.5kg, the rapping hammer is a spherical structure, and the force-bearing end of the impact rod of the cleaning mechanism is a curved surface structure.

[0014] Furthermore, the ratio of the width of the horizontal bar to the vertical bar of the lifting lug is 1:2-1:3.

[0015] Furthermore, the method further comprises the following steps:

[0016] Step 4: Use finite element analysis to perform structural stress analysis on the rapping mechanism, especially at the connection between the rapping rod and the rapping hammer, to simulate the stress conditions under actual working conditions, find out the stress concentration area through analysis, and adjust the structural design according to the results, such as adding reinforcement ribs or optimizing the connection structure, to ensure uniform and reasonable stress;

[0017] Step 5: The surfaces of the rapping rod, connecting rod and hinged rod are all subjected to shot peening, carburizing or nitriding treatment;

[0018] Step six: the rapping rod, connecting rod and hinged rod are all heat treated.

[0019] Furthermore, the connection between the drive shaft and the connecting rod and the connection between the connecting rod and the rapping rod both adopt a graphite copper sleeve structure, and the tolerance requirements are hole tolerance H10 and shaft tolerance d10.

[0020] Furthermore, the diameter of the positioning pin connecting the rapping rod and the lifting ear is 30 mm, and the length of the lifting ear is 50 mm-60 mm.

[0021] Furthermore, the connecting rod, rapping rod, rapping hammer and lifting lug are all made of high-quality carbon structural steel.

[0022] Compared with the prior art, the method for optimizing mechanical vibration force of a waste heat boiler described in the present invention has the following advantages:

[0023] 1. By keeping the center of gravity of the rapping hammer and the axis of the impact rod of the cleaning mechanism in the same straight line, ensure that the rapping hammer is subjected to more uniform force when hammering, and reduce the damage to the system caused by eccentric force. The spacing between the hinge points at the head and tail ends of the rapping rod, the width ratio of the rapping rod, and the counterweight holes set on the rapping rod connecting plate are designed to optimize the center of mass position of the rapping rod. It can effectively reduce the torque generated by the rapping rod during operation and reduce the risk of fatigue damage caused by periodic torque. The connection between the drive shaft and the connecting rod and the connection between the connecting rod and the rapping rod adopts a graphite copper sleeve structure, which can effectively reduce friction and wear and increase the service life of the connection parts. The precise tolerance design (hole tolerance H10, shaft tolerance d10) is adopted to ensure the matching accuracy of the connection parts, thereby improving the stability and reliability of the mechanical transmission.

[0024] 2. The multi-section swing rod structure of the vibration mechanism enables the force to be transmitted and dispersed between multiple points, reducing the situation of single-point force. It effectively reduces the stress concentration phenomenon at each connection point and extends the service life of each component. Due to the multi-section hinged design of the swing rod structure, vibration and impact force can be gradually absorbed and buffered. It helps to reduce the overall vibration of the system and avoid structural fatigue and damage caused by severe vibration. The vibration mechanism effectively improves the force transmission efficiency, reduces structural vibration and stress concentration, and at the same time enhances the flexibility and stability of the system. It is highly adaptable and easy to maintain, meeting the requirements of high efficiency and stability of industrial equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 A schematic diagram of a method for optimizing mechanical vibration force of a waste heat boiler according to an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of the rapping mechanism according to an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the structure of the rapping rod according to an embodiment of the present invention.

[0029] Description of reference numerals:

[0030] 1. Driving shaft; 2. Connecting rod; 3. Vibrating rod; 31. Articulated sleeve; 32. Connecting plate; 33. Articulated frame; 4. Lifting ear; 5. Vibrating hammer; 6. Impact rod. DETAILED DESCRIPTION

[0031] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying 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 limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "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 a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0034] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0035] A method for optimizing the mechanical vibration force of a waste heat boiler, such as Figure 2 As shown, a vibrating mechanism is used to hammer the impact rod 6 of the cleaning mechanism. The vibrating mechanism includes a connecting rod 2, a vibrating rod 3, a vibrating hammer 5 and a lifting lug 4. One end of the connecting rod 2 is detachably connected to the drive shaft 1, and the other end of the connecting rod 2 is provided with a hollow structure, which is hinged to the vibrating rod 3. The end of the vibrating rod 3 away from the connecting rod 2 is hinged to the vibrating hammer 5 through the lifting lug 4. The lifting lug 4 needs to be welded to the vibrating hammer 5. The vibrating hammer 5 is used to hammer the impact rod 6 of the cleaning mechanism. The size of the drive shaft 1 is Φ75. The multi-stage swing rod structure of the vibrating mechanism enables the force to be transmitted and dispersed between multiple points, reducing the situation of single-point force. Effectively reduce the stress concentration phenomenon at each connection point and extend the service life of each component. Due to the multi-stage hinged design of the swing rod structure, vibration and impact force can be gradually absorbed and buffered. It helps to reduce the vibration of the entire system and avoid structural fatigue and damage caused by severe vibration. The vibration mechanism effectively improves the force transmission efficiency, reduces structural vibration and stress concentration, and at the same time enhances the flexibility and stability of the system. It is highly adaptable and easy to maintain, meeting the requirements of high efficiency and stability of industrial equipment.

[0036] Further optimization of the force of the vibration mechanism, such as Figure 1 As shown, the specific steps are:

[0037] Step 1: The center of gravity of the rapping hammer 5 and the axis of the impact rod 6 of the cleaning mechanism are located in the same straight line;

[0038] Step 2: To ensure the dust cleaning effect, it is usually required that the vibration ball has sufficient impact force when hitting the impact rod 6, and that the vibration hammer 5 has sufficient impulse when hitting the impact rod 6 under the action of gravity and centrifugal force. It can be known from mechanical analysis that the vibration hammer 5 converts gravitational potential energy into kinetic energy during operation, which means that the vibration hammer 5 is required to have sufficient mass and the vibration rod 3 is long enough. In actual engineering, the mass of the vibration hammer 5 is 4.5kg-6.5kg, the vibration hammer 5 is a spherical structure, the force-bearing end of the impact rod 6 of the dust cleaning mechanism is a curved surface structure, the distance between the hinge points at the head and tail of the vibration rod 3 is 150mm-250mm, and the distance between the hinge points at the head and tail of the connecting rod 2 is 130mm-170mm;

[0039] Step 3: The diameter of the rapping hammer 5 is 100mm-120mm;

[0040] Step 4: Use finite element analysis to perform structural stress analysis on the rapping mechanism, especially at the connection between the rapping rod 3 and the rapping hammer 5, and at the connection between the lifting lug 4 and the rapping hammer 5 to simulate the stress conditions under actual working conditions, find out the stress concentration area through analysis, and adjust the structural design according to the results, such as adding reinforcing ribs or optimizing the connection structure, to ensure uniform and reasonable stress;

[0041] Step 5: The surfaces of the rapping rod 3, the connecting rod 2 and the hinged rod are all subjected to shot peening, carburizing or nitriding treatment;

[0042] Step 6: The rapping rod 3, the connecting rod 2 and the articulated rod are all heat treated. In this embodiment, 45 / GB / T699 material is used, and the forgings are manufactured and inspected according to the grade II forgings. The finished product is quenched and tempered to ensure the hardness is 230-300HB.

[0043] By keeping the center of gravity of the rapping hammer 5 and the axis of the impact rod 6 of the cleaning mechanism in the same straight line, it is ensured that the rapping hammer 5 is subjected to more uniform force when hammering, reducing the damage to the system caused by eccentric force. The spacing between the hinge points at the ends of the rapping rod 3, the width ratio of the rapping rod 3, and the counterweight hole design of the connecting plate of the rapping rod are designed to optimize the center of mass position of the rapping rod 3. It can effectively reduce the torque generated by the rapping rod 3 during operation and reduce the risk of fatigue damage caused by periodic torque. The connection between the drive shaft 1 and the connecting rod 2 and the connection between the connecting rod 2 and the rapping rod 3 adopts a graphite copper sleeve structure, which can effectively reduce friction and wear and increase the service life of the connection parts. Precision tolerance design (hole tolerance H10, shaft tolerance d10) is adopted to ensure the matching accuracy of the connection parts, thereby improving the stability and reliability of the mechanical transmission. The connecting rod 2 and the drive shaft 1 are bolted and key-positioned, and the key size is 20×12×90.

[0044] During operation, although the mass of the connecting rod 2 and the rapping rod 3 has no direct effect on the dust cleaning effect, the larger mass of the connecting rod 2 and the rapping rod 3 will increase the power consumption of the motor. Therefore, the rapping device has different quality requirements for the connecting rod 2, the rapping rod 3 and the rapping hammer 5. The main function of the connecting rod is to drive the rapping rod to rotate. Therefore, on the premise of ensuring that the connecting rod has sufficient strength and rigidity, the connecting rod is hollowed out to reduce the mass of the connecting rod. In the traditional rapping device, the rapping rod 3 and the rapping hammer 5 are designed as one body. This structure leads to unreasonable force, and the rapping rod 3 often breaks due to fatigue. In view of this problem, the present scheme separates the rapping hammer 5 from the rapping rod 3 and connects them through a hinge. The rapping hammer 5 is designed as an independent rapping hammer 5, and a welding lug 4 is set on it. The advantage of this design is that the impact point always maintains point contact, and the reaction force generated during the impact always passes through the center of the ball, and the center of the ball is located at the center of mass. Therefore, when the rapping hammer 5 hits the impact rod 6, the inertial force of the rapping hammer 5 and the reaction force of the impact rod 6 on the sphere are on the same straight line, and are equal in magnitude and opposite in direction, and no torque is generated due to the inertial force and the reaction force acting on two parallel straight lines. This not only improves the dust cleaning effect by increasing the mass of the rapping hammer 5, but also optimizes the force characteristics of the rapping hammer 5, avoids the rapping hammer 5 from twisting, and the structural form is more reasonable.

[0045] During the falling process of the rapping rod 3, when the rapping hammer 5 hits the impact rod 6, due to the inertia, the rapping rod 3 will continue to move forward, and at this time the speed of the rapping hammer 5 will quickly drop to zero, and the rapping hammer 5 will produce a reverse pulling force on the rapping rod 3 through the lifting lug 4. The line of action of this pulling force points from the hinge point to the rapping hammer 5, and plays a deceleration effect on the rapping rod 3, buffering the inertial force of the rapping rod 3. If the center of mass of the rapping rod 3 does not overlap with the hinge point, the inertial force and pulling force of the rapping rod 3 will form a torque, and the size of the torque is proportional to the distance between the center of mass of the rapping rod 3 and the hinge point, and the larger the distance, the larger the torque. Under the action of a strong and periodic torque, fatigue damage may occur to the rapping rod 3. Therefore, it is required that the distance between the center of mass of the rapping rod 3 and the hinge point is as small as possible. Ideally, when the center of mass overlaps with the hinge point, no torque is generated, and the pulling force and the inertial force act on the same point, which can effectively alleviate the impact force of the rapping rod 3. By properly designing the dimensions of the rapping rod 3, its center of mass coincides with the hinge point.

[0046] At the same time, the greater the mass of the rapping rod 3, the greater its inertia force. Therefore, under the premise of meeting the strength and rigidity requirements, the mass of the rapping rod 3 should be as light as possible. Therefore, the reasonable design of the rapping rod 3 must not only maintain light weight, but also have sufficient strength and rigidity, and ensure that the center of mass is located at the hinge point of the lifting lug 4. It is recommended that the upper and lower width ratios of the rapping rod 3 be 1:1.25 to 1:1.35, and a counterweight hole be set on the connecting plate of the rapping rod 3. Such a design can not only reduce the mass of the rapping rod 3 and reduce the inertia force, but also move the center of gravity of the rapping rod 3 down to the hinge, ensuring that the inertia force and the reverse pull of the lifting lug 4 act on the same point, thereby avoiding the generation of torque and making the structural design more reasonable.

[0047] like Figure 3 As shown, the rapping rod 3 includes an articulated sleeve 31, a connecting plate 32 and an articulated frame 33. The top of the articulated frame 33 is connected to the articulated sleeve 31 through the connecting plate 32. The articulated sleeve 31 is articulated with the connecting rod 2, and the articulated frame 33 is articulated with the lifting lug 4. A counterweight hole is provided in the middle of the connecting plate 32. The width ratio of the side of the articulated sleeve 31 to the side of the articulated frame 33 is 1:1.25-1:1.35. The ratio of the width to the length of the rapping rod 3 is 1:5.5-1:7.5, and the thickness of the rapping rod 3 is not less than 8mm. The width ratio of the horizontal bar to the vertical bar of the lifting lug 4 is 1:2-1:3. The diameter of the locating pin connecting the rapping rod 3 and the lifting lug 4 is 30mm, and the length of the lifting lug 4 is 50mm-60mm. The materials of the connecting rod 2, the rapping rod 3, the rapping hammer 5 and the lifting lug 4 are all high-quality carbon structural steel.

[0048] The connection between the drive shaft 1 and the connecting rod 2 and the connection between the connecting rod 2 and the rapping rod 3 both adopt a graphite copper sleeve structure with tolerance requirements of hole tolerance H10 and shaft tolerance d10, thereby ensuring the coaxiality of each component and bearing a large load, while achieving self-lubricating function and having good wear resistance.

[0049] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for optimizing mechanical vibration force of a waste heat boiler, characterized in that: A rapping mechanism is used to hammer the impact rod of the cleaning mechanism. The rapping mechanism includes a connecting rod, a rapping rod, a rapping hammer and a lifting lug. One end of the connecting rod is detachably connected to the drive shaft. The other end of the connecting rod is provided with a hollow structure. The hollow structure is hinged to the rapping rod. The end of the rapping rod away from the connecting rod is hinged to the rapping hammer through the lifting lug. The rapping hammer is used to hammer the impact rod of the cleaning mechanism to further optimize the force of the rapping mechanism. The specific steps are: Step 1: The center of gravity of the rapping hammer and the axis of the impact rod of the cleaning mechanism are located in the same straight line; Step 2: The distance between the hinge points at both ends of the rapping rod is 150mm-250mm, and the distance between the hinge points at both ends of the connecting rod is 130mm-170mm; Step 3: The diameter of the rapping hammer is 100mm-120mm.

2. The method for optimizing mechanical vibration force of a waste heat boiler according to claim 1, characterized in that: The rapping rod includes an articulated sleeve, a connecting plate and an articulated frame. The top of the articulated frame is connected to the articulated sleeve through the connecting plate. The articulated sleeve is articulated to the connecting rod. The articulated frame is articulated to the lifting ear. A counterweight hole is provided in the middle of the connecting plate.

3. The method for optimizing mechanical vibration force of a waste heat boiler according to claim 1, characterized in that: The width ratio of the side of the hinge sleeve to the side of the hinge frame is 1:1.25-1:1.

35.

4. The method for optimizing mechanical vibration force of a waste heat boiler according to claim 1, characterized in that: The ratio of the width to the length of the rapping rod is 1:5.5-1:7.5, and the thickness of the rapping rod is not less than 8 mm.

5. A method for optimizing mechanical vibration force of a waste heat boiler according to any one of claims 1 to 4, characterized in that: The mass of the rapping hammer is 4.5kg-6.5kg, the rapping hammer is a spherical structure, and the force-bearing end of the impact rod of the cleaning mechanism is a curved surface structure.

6. The method for optimizing mechanical vibration force of a waste heat boiler according to claim 5, characterized in that: The ratio of the width of the horizontal bar to the vertical bar of the lifting lug is 1:2-1:

3.

7. The method for optimizing mechanical vibration force of a waste heat boiler according to claim 5, characterized in that: The following steps are also included: Step 4: Use finite element analysis to perform structural stress analysis on the rapping mechanism, especially at the connection between the rapping rod and the rapping hammer, to simulate the stress conditions under actual working conditions, find out the stress concentration area through analysis, and adjust the structural design according to the results, such as adding reinforcement ribs or optimizing the connection structure, to ensure uniform and reasonable stress; Step 5: The surfaces of the rapping rod, connecting rod and hinged rod are all subjected to shot peening, carburizing or nitriding treatment; Step six: the rapping rod, connecting rod and hinged rod are all heat treated.

8. The method for optimizing mechanical vibration force of a waste heat boiler according to claim 5, characterized in that: The connection between the drive shaft and the connecting rod, as well as the connection between the connecting rod and the rapping rod, are both made of graphite copper sleeve structure, with tolerance requirements of hole tolerance H10 and shaft tolerance d10.

9. The method for optimizing mechanical vibration force of a waste heat boiler according to claim 5, characterized in that: The diameter of the positioning pin connecting the rapping rod and the lifting ear is 30 mm, and the length of the lifting ear is 50 mm-60 mm.

10. The method for optimizing mechanical vibration force of a waste heat boiler according to claim 5, characterized in that: The connecting rod, rapping rod, rapping hammer and lifting lug are all made of high-quality carbon structural steel.

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