Marine energy-saving forward multi-wing centrifugal fan
By adopting structures such as double-section arc blades and wind guide wheels in centrifugal fans, the problem of low energy efficiency caused by the large airflow vortex area inside the impeller is solved, and the improvement of airflow flow efficiency and significant improvement of energy efficiency is achieved.
Patent Information
- Application Number
- CN202411531831.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-02-07
AI Technical Summary
The energy efficiency of existing centrifugal fans is low, mainly because the airflow inside the impeller forms a large vortex area, resulting in large airflow loss and low efficiency.
The double-segment arc blade design is adopted. By controlling the installation angles of the first arc portion and the second arc portion, the blade channels between adjacent blades can accelerate the airflow and reduce the eddy current loss inside the impeller. At the same time, the air guide wheel and flow guide are added to optimize the airflow guidance effect and reduce the loss of internal leakage of the airflow.
By optimizing the blade structure and adding structures such as the wind guide wheel, the airflow loss is significantly reduced, the aerodynamic efficiency and energy efficiency are improved, and the efficient and energy-saving operation effect is achieved.
Smart Images
Figure CN119393353A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of centrifugal fans, and in particular to a marine energy-saving forward multi-blade centrifugal fan. Background Art
[0002] Multi-blade forward centrifugal fans are widely used in ship ventilation and cooling systems due to their advantages such as high pressure coefficient, large flow coefficient, low noise and small size, greatly improving the working environment of ships.
[0003] The centrifugal fan is composed of a volute, an impeller, and a collector, wherein the impeller is composed of a disk, blades, and a wheel cover. The blades are fixed on the disk, and between two adjacent blades is a blade channel for airflow to pass through. Since the impeller basically uses a single arc blade, the speed of the airflow in the blade channel remains basically unchanged. At the same time, the disk is a flat circular plate, and part of the airflow will directly hit the disk after entering the impeller. These factors can easily lead to the formation of a larger vortex area in the airflow inside the impeller, resulting in a large airflow loss and low efficiency, which directly has an adverse effect on the energy efficiency of the centrifugal fan, resulting in the energy efficiency of most centrifugal fans on the market not exceeding Level 2 energy efficiency.
[0004] Therefore, how to further improve the energy efficiency of centrifugal fans is one of the technical problems that need to be solved at present. Summary of the invention
[0005] The present application provides a marine energy-saving forward multi-blade centrifugal fan, which can effectively improve the flow efficiency of airflow, thereby having higher energy efficiency, and adopts the following technical solutions: A marine energy-saving forward multi-blade centrifugal fan comprises an impeller, the impeller comprises a wheel disc and blades; a first arc portion and a second arc portion of the blade, the diameter of the first arc portion is smaller than the diameter of the second arc portion, the first arc portion is located on a side of the second arc portion away from the center of the wheel disc; and the connection between the first arc portion and the second arc portion is tangent; The installation angle of the first arc portion is 30° to 40°, and the installation angle of the second arc portion is 160°-170° By adopting the above technical solution, the blades are set with a double-segment arc, and by controlling the installation angles of the first arc portion and the second arc portion, the blade channel between two adjacent blades accelerates the airflow, so that the airflow inside the impeller can pass through the blade channel more quickly, reducing the eddy current loss inside the impeller and improving the aerodynamic efficiency.
[0006] Preferably, the end of the blade close to the center of the disc is set as the inner end, and the end away from the center of the disc is set as the outer end, and the ratio of the diameter of the circle where the inner end is located to the diameter of the circle where the outer end is located is 0.825.
[0007] By adopting the above technical solution, the reasonable length of the blade path is ensured and the airflow efficiency is improved.
[0008] Preferably, it also includes a current collector and an air guide wheel; the air guide wheel includes a wheel rim and air guide blades arranged inside the wheel rim, and the wheel rim is arranged at the air supply port of the current collector and is rotatably connected to the current collector; The air guide vanes are provided in multiple groups and are spirally arranged along the rim axis; one end of the air guide vanes is located inside the collector, and the other end extends to the inside of the impeller, and the end of the impeller located inside the impeller is warped toward a side away from the rim axis.
[0009] By adopting the above technical scheme, the guide wheel can realize self-rotation through the guide vanes and driven by the airflow, so as to guide the airflow entering the impeller from the collector. On the one hand, it can reduce the obstruction of the airflow at the junction of the collector and the impeller, and on the other hand, it can cause the airflow to generate a cyclone. The cyclone can have a certain guiding effect on the airflow, reduce the turbulence caused by the collision of the airflow with the wheel, reduce the airflow loss, and improve the air intake efficiency.
[0010] Preferably, the angle between the air guide vane and the inner wall of the rim gradually decreases from one end located in the collector to one end located in the impeller, that is, the height of the air guide vane from the inner wall of the rim gradually decreases.
[0011] By adopting the above technical solution, the air guide vanes become flatter from the collector to the inside of the impeller, and the obstruction of the blades to the airflow becomes smaller and smaller, thereby improving the aerodynamic efficiency and avoiding the air guide wheel from having a greater impact on the aerodynamic efficiency.
[0012] Preferably, there is a gap between the collector and the impeller, and a wind shield is provided at a position of the air guide plate opposite to the gap.
[0013] By adopting the above technical solution, due to the existence of the gap, part of the airflow will pass through the gap, resulting in airflow internal leakage loss, which will seriously affect the aerodynamic efficiency of the fan. By setting up the wind shield, the gap can be shielded to a certain extent, thereby reducing airflow loss and improving efficiency.
[0014] Preferably, a wind shield plate opposite to the wind shield is provided on the impeller.
[0015] By adopting the above technical solution, the wind shield plate cooperates with the wind shield piece to further hinder the internal leakage loss of airflow and reduce the airflow loss.
[0016] Preferably, the air guide plate is detachably connected to the wheel rim.
[0017] By adopting the above technical solution, the wind blades are fixedly connected to the wheel rim by bolts, which is convenient for ensuring stability on the one hand, and also convenient for disassembly, assembly and maintenance of the wind guide wheel on the other hand.
[0018] Preferably, a gap adjustment flange is provided at the end of the current collector, and the gap adjustment flange includes a fixed plate connected to the current collector and a floating plate connected to the fixed plate; the floating plate is connected to the fixed plate through a spacing adjustment rod; The floating sheet is also provided with a blocking sheet, and the fixed sheet is provided with a slot corresponding to the blocking sheet. Within the adjustment spacing range of the floating sheet, the blocking sheet is always matched with the slot.
[0019] By adopting the above technical solution, the distance between the fixed plate and the floating plate can be adjusted by rotating the distance adjustment rod, thereby adjusting the gap between the collector and the impeller. The baffle plate is always matched with the slot to block the gap between the baffle plate and the floating plate, thereby reducing the airflow leakage loss.
[0020] Preferably, a deflector is further provided inside the impeller, the deflector is arranged in a triangular cone shape and is coaxial with the impeller, the surface of the deflector is arranged as a concave arc surface, and the curvature of the arc surface corresponds to the curvature of the air guide blade at one end of the inner side of the impeller.
[0021] By adopting the above technical solution, the deflector can guide the airflow in the impeller to prevent the airflow from directly hitting the wheel. At the same time, the surface of the deflector and the surface of the air guide vane form an air duct, which helps the airflow to flow evenly, thereby reducing the eddy current loss in the impeller and improving energy efficiency.
[0022] In summary, the present invention includes at least one of the following beneficial technical effects: 1. The blades are set in double arcs, and by controlling the installation angles of the first arc and the second arc, the blade passage between two adjacent blades accelerates the airflow, allowing the airflow inside the impeller to pass through the blade passage more quickly, reducing the eddy current loss inside the impeller and improving the aerodynamic efficiency; 2. The blades are composed of a first arc-shaped portion and a second arc-shaped portion, and by selecting the installation angles of the first arc-shaped portion and the second arc-shaped portion, the airflow is gradually accelerated in the blade channel, thereby achieving the purpose of improving aerodynamic efficiency; 3. The spacing between the fixed sheet and the floating sheet can be adjusted by turning the spacing adjustment lever, thereby adjusting the gap between the collector and the impeller. The baffle always cooperates with the slot to block the gap between the baffle and the floating sheet, reducing the loss of airflow leakage.
[0023] 4. By adding an air guide wheel, the coordination structure with the deflector further optimizes the airflow guiding effect, ensuring the smooth transition of the airflow inside and outside the impeller. From the collector to the inside of the impeller, the air guide blades become flatter, and the obstruction of the blades to the airflow becomes smaller and smaller, thereby improving the aerodynamic efficiency and avoiding the air guide wheel from having a greater impact on the aerodynamic efficiency; 5. By setting up wind shields and wind shields, the gaps can be shielded to a certain extent, thereby reducing the loss of air leakage, thereby achieving efficient and energy-saving operation. The centrifugal fan of the present application has significantly reduced airflow loss, and has significantly improved aerodynamic efficiency and energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a schematic diagram of the overall structure of the centrifugal fan in this application; Figure 2 It is a schematic diagram of the structure of the impeller and blades in this application; Figure 3 It is a schematic diagram of the relative position relationship between the collector and the impeller in this application; Figure 4 It is a structural schematic diagram of the centrifugal fan after adding an air guide wheel in the present application.
[0025] Markings in the accompanying drawings: 1. impeller; 11. wheel disc; 12. blades; 121. first arc-shaped portion; 122. second arc-shaped portion; 13. deflector; 14. wind shield; 2. collector; 3. gap adjustment flange; 31. fixed plate; 32. floating plate; 33. spacing adjustment rod; 34. baffle; 35. slot; 4. wind guide wheel; 41. rim; 42. wind guide plate; 43. wind shield; 5. volute. DETAILED DESCRIPTION
[0026] The following is combined with Figure 1-4 The present invention is described in further detail.
[0027] Example 1 The marine energy-saving forward multi-blade centrifugal fan provided in the embodiment of the present application is referred to Figure 1 The centrifugal fan includes a volute 5, an impeller 1 and a collector 2.
[0028] Reference Figure 2 The impeller 1 specifically includes a wheel disc 11 and a plurality of blades 12. Each blade 12 is composed of two parts, a first arc-shaped portion 121 and a second arc-shaped portion 122. The diameter of the first arc-shaped portion 121 is smaller than the diameter of the second arc-shaped portion 122. The first arc-shaped portion 121 is located on the side of the second arc-shaped portion 122 away from the center of the wheel disc 11; and the connection between the first arc-shaped portion 121 and the second arc-shaped portion 122 is tangent, the installation angle of the first arc-shaped portion 121 is 30° to 40°, and the installation angle of the second arc-shaped portion 122 is 160°-170°.
[0029] In the embodiment of the present application, the installation angle of the first arc-shaped portion 121 is preferably 36°, while the installation angle of the second arc-shaped portion 122 is 165°. Thus, the blade channel between two adjacent blades 12 is larger at the end closer to the center of the impeller 1 and smaller at the end away from the center of the impeller 1, so that the airflow in the blade channel is gradually accelerated, thereby achieving the purpose of improving the aerodynamic efficiency.
[0030] Since a plurality of blades 12 are arranged in a ring shape on the wheel disc 11, in order to further improve the aerodynamic efficiency, it is necessary to ensure that the length of the blade path is within a certain range. In the present application, the end of the blade 12 close to the center of the wheel disc 11 is set as the inner end, and the end away from the center of the disc is set as the outer end, and the ratio of the diameter of the circle where the inner end is located to the diameter of the circle where the outer end is located is 0.825.
[0031] Reference Figure 3 Further, the collector 2 includes a cylindrical structure and a gradually contracting and expanding conical structure, and the conical structure serves as an air outlet. The air outlet of the collector 2 is also provided with a gap adjustment flange 3. The gap between the collector 2 and the impeller 1 is adjusted by the gap adjustment flange.
[0032] In the present application, the outer diameter of the impeller 1 is 360 mm, the ratio of the inner and outer diameters of the blades 12 is 0.825, the blades 12 are in the form of a combination of a first arc portion 121 and a second arc portion 122, and the first arc portion 121 and the second arc portion 122 are tangent at the intersection. The first arc portion 121 is used as the inlet of the blade channel, and the installation angle is 36°; the second arc portion 122 is used as the outlet of the blade channel, and the installation angle is 165°, which controls the airflow in the blade channel to be gradually accelerated. The number of blades 12 is 58, and the width of the blades 12 is 170 mm. Through CFD analysis, it is found that the gas in the impeller 1 conforms to the flow law, which improves the aerodynamic efficiency.
[0033] The volute is an involute spiral. By optimizing the volute profile, the volute outlet diffusion angle is 31° and the volute width is 250mm. CFD calculation shows that the volute is more compatible with the impeller 1 and reduces the eddy current loss in the casing.
[0034] The inlet of the collector 2 is in a bell-mouth shape, which reduces the flow loss at the inlet. The gap between the collector 2 and the impeller 1 is controlled to be 2.5 mm through the gap adjustment flange 3, which reduces the internal leakage loss.
[0035] After testing, the full-pressure efficiency of the whole machine is 69.8%, which is higher than the national level 1 energy efficiency requirement (the full-pressure efficiency corresponding to level 1 energy efficiency is 67%).
[0036] Example 2 The marine energy-saving forward multi-blade centrifugal fan provided in the embodiment of the present application is referred to Figure 3 and Figure 4On the basis of embodiment 1, an air guide wheel 4 is added. The air guide wheel 4 is arranged between the current collector 2 and the impeller 1. The current collector 2 is connected to the air guide wheel 4 through a gap adjustment flange 3.
[0037] In addition, compared with Example 1, the structure of the adjusting flange 3 is further improved in the embodiment of the present application. Figure 3 The gap adjustment flange 3 includes a fixed plate 31, a floating plate 32 and a spacing adjustment rod 33. The fixed plate 31 is fixedly connected to the collector 2 by bolts. The floating plate 32 is arranged opposite to the fixed plate 31, and the adjustment rod is rotatably connected to the fixed plate 31 and is screwed to the fixed plate 31. Therefore, the spacing between the fixed plate 31 and the floating plate 32 can be adjusted by rotating the spacing adjustment rod 33.
[0038] A baffle 34 is also provided on the floating sheet 32, and a slot 35 corresponding to the baffle 34 is opened on the fixed sheet 31. Within the adjustment spacing range of the floating sheet 32, the baffle 34 always cooperates with the slot 35, thereby blocking the gap between the baffle 34 and the floating sheet 32 to avoid airflow loss.
[0039] Reference Figure 4 The guide wheel 4 includes a wheel rim 41 and a plurality of guide vanes 42 disposed inside the wheel rim 41. The wheel rim 41 is disposed inside the floating vane 32, and a roller is disposed between the two, so that the wheel rim 41 and the floating vane 32 form a bearing to realize the free rotation of the wheel rim 41. At the same time, the gap between the wheel rim 41 and the impeller 1 can be adjusted by the gap adjustment flange 3. By reducing the gap, the internal unloading loss of the airflow is reduced, and the aerodynamic efficiency of the centrifugal fan is improved.
[0040] The air guide blade 42 is fixedly connected to the wheel rim 41 by bolts, which is convenient for ensuring stability on the one hand, and also convenient for disassembly, assembly and maintenance of the air guide wheel 4 on the other hand.
[0041] The air guide blade 42 is spirally arranged with the central axis of the wheel rim 41 and fixed on the inner side of the wheel rim 41. One end of the air guide blade 42 extends to the inside of the collector 2, and the other end extends to the inside of the impeller 1. When the fan is working, the airflow enters from the collector 2, and the air guide wheel 4 rotates under the action of the airflow, and the rotation direction of the air guide wheel 4 is consistent with the rotation direction of the impeller 1. At the same time, under the action of the air guide blade 42, a cyclone will be formed on the periphery of the airflow.
[0042] When the airflow enters the impeller from the collector 2, the air outside the airflow will be affected by the impeller 1, and its flow direction will change from flowing along the axial direction of the impeller 1 to flowing along the radial direction of the impeller 1, while the air at the center of the airflow is less affected by the impeller 1, so it will directly hit the wheel 11 to generate turbulence. The cyclone will have a certain guiding effect on the airflow entering the impeller 1, reducing the turbulence generated after the airflow hits the wheel 11, thereby improving the stability of the airflow and helping to improve the aerodynamic efficiency.
[0043] The angle between the air guide vane 42 and the inner wall of the wheel rim 41 gradually decreases from one end located at the collector 2 to the end located inside the impeller 1, so as to gradually reduce the resistance of the air guide vane 42 to the periphery of the airflow. The end of the air guide vane 42 located inside the impeller 1 is warped toward the side away from the axis of the wheel rim 41, which can reduce the impact on the airflow on the one hand, and cooperate with the deflector 13 set at the center of the wheel disc 11 on the other hand to form an air duct inside the impeller 1 to improve the starting efficiency.
[0044] Specifically, a deflector 13 is further provided inside the impeller 1. The deflector 13 is arranged in a triangular cone shape and is coaxial with the impeller 1. The surface of the deflector 13 is arranged as a concave arc surface, and the curvature of the arc surface corresponds to the curvature of the impeller 1 at one end inside the impeller 1.
[0045] Furthermore, a wind shield 43 is provided on the air guide 42, and the wind shield 43 is located at the gap between the rim 41 and the impeller 1 and is arranged directly opposite the gap to improve the shielding effect of the gap and reduce the inward tilt of the airflow. A wind shield 14 is also provided at one end of the impeller 1 facing the rim 41, and the wind shield 14 is arranged opposite to the wind shield 43, thereby further improving the wind shielding effect.
[0046] The volute is in the shape of an involute spiral. By optimizing the volute profile, the performance of the volute and the impeller 1 is more matched, and the loss of vortex in the volute is reduced.
[0047] The implementation principle of this embodiment is as follows: This application effectively reduces the vortex area formed by the airflow inside the impeller 1 by optimizing the structure of the blades 12 and adding structures such as the guide wheel 4, thereby improving the flow efficiency of the airflow. The design of the double-arc blades 12 allows the airflow to be gradually accelerated in the blade channel, reducing airflow losses and improving the overall energy efficiency of the centrifugal fan. In addition, the matching structure of the guide wheel 4 and the deflector 13 further optimizes the airflow guiding effect, ensures the smooth transition of the airflow inside and outside the impeller 1, reduces the leakage loss in the airflow, and thus achieves an efficient and energy-saving operation effect. Compared with the prior art, the centrifugal fan of this application has significant improvements in airflow losses, aerodynamic efficiency and energy efficiency.
[0048] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, all equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. A marine energy-saving forward multi-blade centrifugal fan, characterized in that: The impeller (1) comprises a wheel disc (11) and a blade (12); the blade (12) has a first arc-shaped portion (121) and a second arc-shaped portion (122); the diameter of the first arc-shaped portion (121) is smaller than the diameter of the second arc-shaped portion (122); the first arc-shaped portion (121) is located on a side of the second arc-shaped portion (122) away from the center of the wheel disc (11); and the first arc-shaped portion (121) and the second arc-shaped portion (122) are tangent at a connection point; The installation angle of the first arc-shaped portion (121) is 30° to 40°, and the installation angle of the second arc-shaped portion (122) is 160°-170°.
2. The marine energy-saving forward multi-blade centrifugal fan according to claim 1 is characterized in that: The end of the blade (12) close to the center of the wheel disc (11) is set as the inner end, and the end away from the center of the wheel disc is set as the outer end, and the ratio of the diameter of the circle where the inner end is located to the diameter of the circle where the outer end is located is 0.
825.
3. The marine energy-saving forward multi-blade centrifugal fan according to claim 1 is characterized in that: It also includes a current collector (2) and an air guide wheel (4); the air guide wheel (4) includes a wheel rim (41) and air guide blades (42) arranged inside the wheel rim (41); the wheel rim (41) is arranged at the air supply port of the current collector (2) and is rotatably connected to the current collector (2); The air guide blades (42) are provided in multiple groups and are spirally arranged about the axis of the wheel rim (41); one end of the air guide blade (42) is located inside the collector (2), and the other end extends to the inside of the impeller (1); and the end of the impeller (1) located inside the impeller (1) is warped towards a side away from the axis of the wheel rim (41).
4. The marine energy-saving forward multi-blade centrifugal fan according to claim 3 is characterized in that: The included angle between the air guide blade (42) and the inner wall of the wheel rim (41) gradually decreases from one end located at the collector (2) to one end located inside the impeller (1), that is, the height of the air guide blade (42) from the inner wall of the wheel rim (41) gradually decreases.
5. The marine energy-saving forward multi-blade centrifugal fan according to claim 4 is characterized in that: There is a gap between the collector (2) and the impeller (1), and a wind shield (43) is provided at a position of the wind guide piece (42) opposite to the gap.
6. The marine energy-saving forward multi-blade centrifugal fan according to claim 5 is characterized in that: The impeller (1) is provided with a wind shielding plate (14) opposite to the wind shielding piece (43).
7. The marine energy-saving forward multi-blade centrifugal fan according to claim 5 is characterized in that: The air guide piece (42) is detachably connected to the wheel rim (41) to facilitate installation of the air guide piece (42).
8. The marine energy-saving forward multi-blade centrifugal fan according to claim 3 is characterized in that: The end of the current collector (2) is provided with a gap adjustment flange (3), and the gap adjustment flange (3) comprises a fixed plate (31) connected to the current collector (2) and a floating plate (32) connected to the fixed plate (31); the floating plate (32) is connected to the fixed plate (31) via a gap adjustment rod (33); The floating sheet (32) is also provided with a blocking sheet (34), and the fixed sheet (31) is provided with a slot (35) corresponding to the blocking sheet (34). Within the adjustment spacing range of the floating sheet (32), the blocking sheet (34) always cooperates with the slot (35).
9. The marine energy-saving forward multi-blade centrifugal fan according to claim 3 is characterized in that: A flow guide (13) is also provided inside the impeller (1); the flow guide (13) is arranged in a triangular cone shape and is coaxial with the impeller (1); the surface of the flow guide (13) is arranged as a concave arc surface, and the curvature of the arc surface corresponds to the curvature of the impeller (1) at one end located on the inner side of the impeller (1).