Low wind resistance, inherent frequency adjustable, air cooler fan bridge with TLD function

Abstract

The application relates to an air cooler. The purpose is to provide an air cooler fan bridge with low wind resistance, adjustable inherent frequency and TLD damping function, which also has the characteristics of simple structure and convenient use. The technical scheme is an air cooler fan bridge with low wind resistance, adjustable inherent frequency and TLD damping function; characterized in that: the outer sides of the middle parts of the two main beams are guide surfaces which are inclined inward from top to bottom, and the two sides of the support beam are guide surfaces which are inclined to the vertical center line from top to bottom; so as to guide the airflow.

Description

Technical Field

[0001] This invention relates to an air cooler, and more particularly to a fan bridge structure for an induced draft direct air condenser that uses a large-diameter axial flow fan in conjunction with a high-power motor. Background Technology

[0002] Currently, more and more large-scale oil refining projects and waste incineration power generation projects are choosing to use large-diameter fans with long tube bundles as the air coolers for their turbines, which have a relatively lower overall cost.

[0003] Conventional air coolers using large axial flow fans have their fan drive systems mounted on dedicated fan bridges. Large-diameter fans (over 10 meters in diameter) typically employ high-power motors of 160kW or more, generally exceeding 1.8 meters in height. The motor is connected to a gearbox at the bottom via a flange, and the gearbox drives the fan. The most common problem encountered with fan drive systems is vibration, primarily occurring in the fan bridge itself and at the non-drive end (suspended end) of the motor. The causes of vibration are mainly resonance in the fan drive system, insufficient bridge rigidity, and insufficient rigidity of the motor housing. Such situations often require large-scale shutdowns for maintenance, developing repair plans, construction, and testing, which can lead to decreased air cooler performance and reduced plant production. Therefore, to ensure the long-term safe operation of the equipment and compliance with relevant standards, the vibration problem of the fan drive system must be addressed.

[0004] CN205207282U discloses a fan bridge with vibration reduction function, which includes a fan bridge body (1) and a vibration reduction device (2) for supporting the fan bridge body (1), wherein the main body of the vibration reduction device is a spring. CN205226196U discloses a rubber vibration damping pad device for air-cooled fan bridge; it utilizes the good vibration reduction, noise reduction and resistance energy dissipation performance of rubber material to reduce the energy transmission when the fan bridge vibrates, reduce the impact force of the fan bridge on the air-cooled steel truss platform, and avoid resonance damage to the entire direct air-cooling system structure. However, the vibration reduction measures adopted by the above two solutions can only target the vertical vibration of the fan bridge, and the improvement of the vibration at both ends cannot guarantee the vibration control of the gearbox installation position in the middle of the bridge, and cannot deal with resonance and vibration problems at the non-drive end of the motor. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings in the above-mentioned background technology and provide an air cooler fan bridge with low wind resistance, adjustable natural frequency, and TLD vibration damping function. The air cooler fan bridge should also have the characteristics of simple structure and convenient use.

[0006] A low-drag, frequency-adjustable, TLD-equipped air-cooled fan bridge includes a horizontally arranged bridge beam resting on an air-cooling platform at both ends, and bending-resistant reinforcing frames erected and fixed on both sides of the bridge beam in the width direction. The bridge beam includes two main beams located on both sides of the bridge beam in the width direction, and several support beams horizontally fixed between the two main beams and arranged parallel to each other. The main beams and support beams are all steel sections with several stiffening ribs added to the left and right sides and having an I-shaped cross-section.

[0007] The feature is that the outer surfaces of the middle section of the two main beams are guide surfaces that slope inward from top to bottom, and the two sides of the support beam are guide surfaces that slope downward from top to bottom towards the vertical center line; so as to guide the airflow.

[0008] The structure of the guide surface of the main beam is formed by first cutting off part of the lower flange on the outer side of the long steel section, and cutting off part of several stiffening ribs on the same side of the steel section. Then, several main beam guide plates are welded and fixed in the middle of the steel section. Each main beam guide plate is connected to the ends of the upper and lower flanges and the cut ends of two adjacent stiffening ribs, thereby forming several independent sealed containers on the steel section to contain liquids with changeable mass. By changing the overall weight of the cable tray, the natural frequencies of each order of the cable tray are adjusted. Vibration is weakened and absorbed by the back-and-forth oscillation of the liquid in the container (LTD function).

[0009] The structure of the guide surface of the support beam is formed by first cutting off part of the lower flange on both sides of the short steel section, and cutting off part of several stiffening ribs located on both sides of the steel section. Then, several support beam guide plates are welded and fixed on the left and right sides of the steel section. Each support beam guide plate is connected to the ends of the upper and lower flanges and the cut ends of two adjacent stiffening ribs, thereby forming several independent sealed containers on the I-shaped steel section to contain liquids with changeable mass. By changing the overall weight of the cable tray, the natural frequencies of each order of the cable tray are adjusted, and the vibration is weakened and absorbed by the back-and-forth oscillation of the liquid in the container (LTD function).

[0010] The upper flange of the steel section has several injection ports that pass through the sealed container, and each injection port is equipped with a corresponding sealing head. The guide plate has several vent ports that pass through the sealed container, and each vent port is equipped with a corresponding sealing head, so as to facilitate the quantitative adjustment of the liquid volume in the sealed container.

[0011] Several vents are arranged along the vertical direction of the baffle plate to facilitate the adjustment of the liquid volume in the sealed container.

[0012] The length of the middle section is more than 80% of the length of the main beam.

[0013] The high, medium, and low pressure vents on all guide plates on the main beam are all positioned at the same height, as are the high, medium, and low pressure vents on all guide plates on the support beam, to facilitate capacity adjustment.

[0014] The injection port and the vent port are both screw holes, and the sealing head is a bolt equipped with a sealing ring.

[0015] The steel section is an I-beam or a transversely arranged H-beam.

[0016] The beneficial effects of this invention are:

[0017] 1. By modifying the wind turbine bridge and adding guide vanes, the airflow under the wind turbine bridge can be streamlined, reducing the wind pressure on the wind turbine bridge when the wind turbine blades pass through the bottom of the wind turbine bridge. At the same time, it reduces the excitation effect of the wind turbine blades on the bridge as a resonant excitation source due to repeated changes in wind pressure, thus reducing the possibility of large-intensity resonance and the vibration intensity when resonance occurs.

[0018] 2. By using beams, stiffening ribs, and guide plates to form a container with multiple vents, different masses and types of substances can be added to the container to quickly achieve the TLD (tunable liquid damper) function, natural frequency adjustment function, and stiffness adjustment function that meet the design requirements.

[0019] 3. For occasional vibration problems on site, the above functions all have the ability to be flexibly adjusted on site. If it is initially determined that there is no mechanical failure in the equipment, targeted low-cost vibration treatment can be attempted without stopping the machine for maintenance.

[0020] 4. The design of wind turbine bridges can reduce the redundancy of stiffness (to avoid excessive amplitude) and mass (to control natural frequency) at the beginning of the design process, thereby reducing the amount of steel used. At the same time, it can achieve standardized and serialized design of wind turbine bridges with different spans and matching wind turbine motors. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the main structure of the present invention.

[0022] Figure 2 yes Figure 1 A schematic diagram showing the separation of the bridge girder and the bending stiffener.

[0023] Figure 3 This is a bottom-view structural diagram of the present invention.

[0024] Figure 4 yes Figure 3 A schematic diagram of the BB cross-sectional structure.

[0025] Figure 5 yes Figure 1A schematic diagram of the AA cross-sectional structure.

[0026] Figure 6 This is a schematic diagram of the right-side structure of the present invention.

[0027] Figure 7 yes Figure 3 A schematic diagram of the DD cross-sectional structure.

[0028] Figure 8 Depend on Figure 7 It is formed by rotating 90 degrees counterclockwise.

[0029] Figure 9 yes Figure 5 A magnified structural diagram of part E in the diagram.

[0030] Figure 10 yes Figure 4 A magnified schematic diagram of the F part in the diagram.

[0031] Figure 11 This is a three-dimensional structural diagram of a conventional air cooler.

[0032] Figure 12 This is a schematic diagram of the main structure of a conventional air cooler.

[0033] The following are the labeling elements in the diagram: 1. Main beam; 1-1. Long steel section; 1-2. Main beam guide plate; 1-3. Main beam injection sealing head; 1-4. Main beam discharge sealing head; 2. Support beam; 2-1. Short steel section; 2-2. Support beam guide plate; 2-3. Support beam injection sealing head; 2-4. Support beam discharge sealing head; 3. Diagonal brace; 4. Reinforcing rib; 10. Bridge beam; 20. Bending reinforcement frame. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings, but the present invention is not limited to the following embodiments.

[0035] Figure 11 , Figure 12 The air cooler shown uses a large axial flow fan. The fan drive system is mounted on a special fan bridge. Large-diameter fans with a diameter of 9 meters or more often use high-power motors of 160KW or more. The height of the motor body is generally greater than 1.8 meters. The motor is connected to the gearbox at the bottom through a flange. The gearbox drives the fan to run by reducing speed.

[0036] The above-mentioned wind turbine bridge (see Figures 1 to 3 This includes a horizontally arranged bridge beam 10 resting at both ends on an air-cooled platform (omitted in the figure) and bending stiffeners 20 erected and fixed on both sides of the bridge beam in the width direction (for clarity, ...). Figure 2The bridge beam is specifically separated from the bending stiffening frame. The bridge beam includes two main beams 1 located on both sides of the width direction of the bridge beam, several support beams 2 horizontally fixed between the two main beams and arranged parallel to each other, and several diagonal braces 3 for strengthening stiffness. The main beams and support beams all use I-shaped steel sections (preferably I-beams or transversely arranged H-beams) as the skeleton. To increase the stiffness of the beam, several stiffening ribs 4 are welded and fixed between the upper and lower flanges on both sides of the steel section. The surface of each stiffening rib is perpendicular to the length direction of the steel section, its outer side is flush with the ends of the upper and lower flanges, and the edges of the remaining parts are matched with the wall surface of the steel section and welded to maintain a seal. A certain distance is maintained between adjacent stiffening ribs (the distance is determined according to design requirements). Figure 1 , Figure 2 It can be seen that near the two ends of the main beam (each end being less than one-tenth the length of the main beam), the number of stiffening ribs gradually increases, and the distance between adjacent stiffening ribs gradually decreases. And from... Figure 5 It can be seen that only one reinforcing rib needs to be added to each side of each support beam.

[0037] The above are all existing technological structures.

[0038] In order to enable the wind turbine bridge to have low wind resistance, adjustable natural frequency and TLD vibration reduction function, the present invention improves the structure of the above-mentioned wind turbine bridge.

[0039] One improvement is to modify the middle section of the outer surface of the two main beams (this middle section accounts for more than 80% of the length of the main beams), changing the original vertical outline of this section to a guide surface that slopes inward from top to bottom (the inner side of the two main beams, because it needs to connect the fixed support beams and diagonal braces, will not be modified); the left and right sides (both sides in the width direction, i.e.) of each support beam. Figure 10 The two sides (left and right sides) have also been changed from the original vertical outline to two guide surfaces that are inclined from top to bottom towards the vertical center line; in order to guide the airflow, so that the wind turbine bridge has a low wind resistance flow guiding design, thereby reducing the wind pressure generated on the bridge when the wind turbine blades pass through the bottom of the wind turbine bridge, thereby reducing the vibration excitation effect of the wind pressure that repeatedly changes when the wind turbine blades pass through on the bridge.

[0040] The specific improvement is as follows: the middle part of the long steel section 1-1 used in each main beam (this part accounts for more than 80% of the length of the steel section) is cut. In this invention, the lower flange of the outer side of the steel section (i.e. the side facing away from the other long steel section) is first cut off. At the same time, a part of all the stiffening ribs in this part on the same side is also cut off in a straight line, so that the line connecting the end of the upper flange and the end of the lower flange (the cut-off part) of the outer side of the long steel section is aligned with (or coincides with) the outer edge of the cut stiffening rib. Then, a main beam guide plate 1-2 connecting the upper and lower flange edges is welded and fixed on the cut side, so that the side of the main beam becomes an inclined guide surface.

[0041] It is important to note that because each long steel section has several stiffening ribs arranged at varying distances on its outer side, the length of each guide plate (the dimension parallel to the length of the main beam) needs to be determined based on the distance between two adjacent stiffening ribs. Furthermore, during welding, the upper and lower edges of each guide plate are welded to the upper and lower flanges for a seal, while the two sides along the length direction need to be welded to the cut portions of the corresponding two-sided stiffening ribs for a seal. This ensures that the cavity formed after welding has a sealing performance, achieving the effect of a container. Additionally, this treatment is only required in the middle of each main beam, and not near the two ends (because the distance between two adjacent stiffening ribs is too short, making the space for container construction too small). Therefore, due to... Figure 1 It can be seen that five main beam guide plates were sealed and welded on each main beam, forming five containers.

[0042] Correspondingly, each support beam is also treated accordingly. Unlike the main beam, each support beam requires corresponding cutting and sealing on both sides (the cutting method and the sealing method of the guide plates are the same as described above). In addition, only one stiffening rib is arranged in the center on one side of each support beam, so only two guide plates need to be welded and sealed. As shown in the figure, four containers are formed on both sides of each support beam. During the treatment, the lower flanges on both sides of the short steel 2-1 used for each support beam are first cut (the stiffening ribs are also cut flush). Then, the guide plates 2-2 of the support beam, which connect the upper and lower flange edges to the cut parts of the stiffening ribs, are welded and fixed on both sides respectively. This makes the two sides of the support beam become inclined guide surfaces, and the cross-sectional profile of the support beam is also a trapezoid with a larger top and a smaller bottom. In this way, the wind resistance of the airflow driven by the fan from bottom to top passing through the main beam and support beam is reduced, and the gas flow is smoother.

[0043] As a preferred option, the lower flange cut off from each side of the steel section (long steel section or short steel section) is one-quarter to one-third of the transverse width of the steel section; this is sufficient to meet the requirements.

[0044] The second improvement involves adding inlet and outlet ports to the containers on the main beams and support beams, along with corresponding sealing heads. This allows for adjustment of the liquid volume within the containers, enabling the regulation of the cable tray's natural frequencies by altering its overall weight. Counterweighting can be easily implemented as needed to prevent the cable tray from reaching significant resonant frequencies. The back-and-forth movement of the liquid within the containers also provides the wind turbine cable tray with a flexibly configurable TLD (tuned liquid damper) function in the horizontal direction, reducing and partially absorbing horizontal cable tray vibrations.

[0045] The injection port is located on the upper flange of the steel section and extends through the corresponding container to allow for the injection of selected liquids as needed. Each container has an injection port and several drain ports, each equipped with a corresponding sealing head to adjust the liquid volume within the container according to frequency requirements. Figure 1 It is known that each of the five containers on each main beam is equipped with an injection port with a sealing head; each of the four containers on both sides of each support beam is also equipped with an injection port with a sealing head. The vents are located on the guide plates of the main beams and the support beams to release the liquid in the containers as needed.

[0046] like Figure 9 As shown: Each container on the main beam has an injection port that penetrates the upper flange of the long steel section and is equipped with a main beam injection sealing head 1-3; each main beam guide plate has three main beam vents, each equipped with a main beam vent sealing head 1-4; these main beam vents are also arranged at vertical intervals (divided into high, medium, and low levels) to facilitate the adjustment of the liquid volume inside the container. Figure 10 As shown: Each container on the support beam has an injection port through the upper flange of the steel section and is equipped with a support beam injection sealing head 2-3; each support beam guide plate also has three support beam discharge ports, each support beam discharge port is equipped with a support beam discharge sealing head 2-4; these support beam discharge ports are also arranged at intervals (divided into high, medium and low levels) to facilitate the adjustment of the liquid volume in the container.

[0047] Preferably, the high, medium, and low pressure vents on all guide vanes of the main beam are positioned at a uniform height to facilitate capacity adjustment. Similarly, the high, medium, and low pressure vents on all guide vanes of the support beams are positioned at a uniform height to facilitate capacity adjustment.

[0048] Preferably, the injection port and the discharge port are both screw holes, and the sealing head can be a bolt equipped with a sealing ring.

[0049] The liquid is water or other liquid substance. Alternatively, fine particles such as sand can be used instead of liquid in the container of this invention.

[0050] The working principle of this invention is:

[0051] By unscrewing the sealing head at the inlet, liquid can be poured into the container; by unscrewing the sealing head at the outlet, liquid can be drained from the container; by unscrewing the sealing heads at outlets at different heights on the same guide plate, the liquid capacity in the corresponding container can be adjusted.

[0052] When the air cooler is working, if there is slight swaying / vibration in the width direction of the fan bridge and swaying in the width direction of the non-drive end of the motor, a specific amount of liquid (water or other liquid) can be poured into the container of the support beam to realize the function of TLD (tuned liquid damper) to reduce and absorb the vibration in the corresponding direction.

[0053] If resonance occurs on site due to the overlap of the excitation source frequency and a certain natural frequency of the wind turbine bridge, a specific amount of water / sand or other substances can be poured into the container of the main beam to adjust the natural frequencies of the wind turbine bridge by changing the weight of the wind turbine bridge, so as to avoid the main excitation frequency.

[0054] The features of this invention are:

[0055] By utilizing the container design formed by the guide plate, bridge beam, and stiffening ribs, and by filling the container with liquid or particulate matter, the TLD tuning liquid damping function, the natural frequency adjustment function of the wind turbine bridge, and the stiffness adjustment function of the wind turbine bridge are realized. It also provides convenient operation and adjustment measures to improve the horizontal and vertical vibration of the wind turbine bridge.

[0056] The above-mentioned flexible adjustment measures for various characteristics of the wind turbine bridge can provide users with a series of simple adjustment measures when occasional vibration problems occur at the air cooler operation site. Users can choose to try one or more of these measures at the same time, which is helpful for solving problems and analyzing the causes of problems.

Claims

1. A low-drag, frequency-adjustable air cooler fan bridge with a tuned liquid damper for vibration reduction, comprising a horizontally arranged bridge beam (10) resting on an air-cooling platform at both ends, and a bending-resistant reinforcing frame (20) erected and fixed on both sides of the bridge beam in the width direction; the bridge beam comprises two main beams (1) located on both sides of the bridge beam in the width direction, and several support beams (2) horizontally fixed between the two main beams and arranged parallel to each other; the main beams and support beams are all steel sections with several stiffening ribs added on the left and right sides and with an I-shaped cross section; Its features are: The outer surfaces of the middle section of the two main beams are guide surfaces that slope inward from top to bottom, and the two sides of the support beam are guide surfaces that slope downward from top to bottom towards the vertical center line; in order to guide the airflow. The structure of the guide surface of the main beam is formed by first cutting off part of the lower flange of the long steel (1-1) used for the main beam, and cutting off part of a number of stiffening ribs (4) located on the same side of the steel. Then, several main beam guide plates (1-2) are welded and fixed in the middle part of the steel. Each main beam guide plate is connected to the ends of the upper and lower flanges and the cut ends of two adjacent stiffening ribs, thereby forming several independent closed containers on the steel to contain liquid that adjusts the natural frequency of the vibrating bridge through mass change. The structure of the guide surface of the support beam is formed by first cutting off part of the lower flange on both sides of the short steel (2-1) used for the support beam, and cutting off part of a number of stiffening ribs located on both sides of the steel. Then, several support beam guide plates (2-2) are welded and fixed on the left and right sides of the steel. Each support beam guide plate is connected to the ends of the upper and lower flanges and the cut ends of two adjacent stiffening ribs, thereby forming several independent closed containers on the I-shaped steel to contain liquid that adjusts the natural frequency of the vibrating bridge through mass changes. The upper flange of the steel section has several injection ports that pass through the sealed container and each injection port is equipped with a corresponding injection sealing head. The guide plate has several vent ports that pass through the sealed container and several vent sealing heads that are equipped with each vent port, so as to facilitate quantitative adjustment of the liquid volume in the sealed container. Several vents are arranged along the vertical direction of the baffle plate to facilitate the adjustment of the liquid volume in the sealed container.

2. The air cooler fan bridge with low wind resistance, adjustable natural frequency, and damping function of tuned liquid damper as described in claim 1, characterized in that: The length of the middle section is more than 80% of the length of the main beam.

3. The air cooler fan bridge with low wind resistance, adjustable natural frequency, and damping function of tuned liquid damper as described in claim 2, characterized in that: The high, medium, and low pressure vents on all guide plates on the main beam are all positioned at the same height, as are the high, medium, and low pressure vents on all guide plates on the support beam, to facilitate capacity adjustment.

4. The air cooler fan bridge with low wind resistance, adjustable natural frequency, and damping function of tuned liquid damper as described in claim 3, characterized in that: The injection port and the discharge port are both screw holes, and the sealing head is a bolt with a sealing ring.

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