Annular vortex-eliminating boosting type energy-saving device behind ship propeller

Abstract

The invention discloses an annular vortex-eliminating boosting type energy-saving device behind a ship propeller, and relates to the technical field of ships, in particular to an energy-saving device behind the propeller. Comprising a cone on a propeller shaft, vortex elimination fins, a guide pipe, rectification blades in the guide pipe and rear flow guide blades, the small-diameter end of the cone is fixedly connected with a propeller hub, the vortex elimination fins, the rectification blades and the rear flow guide blades are arranged on the cone and the propeller hub in the circumferential direction and are connected in series and installed in the guide pipe in a penetrating mode, and annular blades are installed on the guide pipe in the circumferential direction. The invention relates to an annular vortex-eliminating boosting type energy-saving device behind a ship propeller, which can be used as an appendage device of a ship and is mounted at the rear end of the propeller so as to realize the adjustment of a stern pressure field, recycle the circumferential rotation energy of stern flow, attenuate or divide vortexes and play roles in reducing vortex resistance and providing additional thrust. Meanwhile, the pores of the annular blades can effectively reduce the generation of vortexes, so that the damage of noise and cavitation to the propeller is reduced, and the improvement of the propelling efficiency, energy conservation and efficiency improvement are realized.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding and marine engineering technology, specifically to a device for eliminating hub vortices behind a propeller and recovering wake energy loss to generate additional thrust. Background Technology

[0002] With the accelerating pace of global trade integration, ships, as the primary means of maritime transport, will play an increasingly important role. However, this has also led to problems such as excessive consumption of mineral energy and increasingly significant greenhouse gas emissions. The mandatory implementation of the EEDI index and other requirements for energy conservation and emission reduction in shipping present both opportunities and challenges for the industry. Energy conservation and emission reduction have become particularly important in the development and operation of ships, and they also align with the requirements of shipping companies for cost reduction, efficiency improvement, and sustainable development.

[0003] To achieve this goal, scholars both domestically and internationally have conducted extensive research on energy-saving methods for ships. For ships in operation, whose hull shape is relatively fixed, energy efficiency design modifications can be achieved by installing hydrodynamic energy-saving devices on the hull surface near the propeller. These devices improve the propeller's inflow conditions through rectification, recovering lost propeller stern flow energy and achieving energy conservation and efficiency. Because these energy-saving devices are simple in structure, easy to manufacture, low in cost, and have excellent energy-saving effects, they are suitable for both new ship installations and retrofitting of older ships, making them highly favored by ship owners in engineering applications.

[0004] While conventional energy-saving devices are widely used in commercial vessels, and previous equipment recovered some energy lost due to hub vortices and utilized the rotating water flow behind the propeller to propel the fins, its effect on increasing propeller thrust was not significant, which is a drawback. In contrast, the rear-mounted annular vortex-eliminating booster energy-saving device improves upon this. It disperses hub vortices behind the propeller, effectively reducing cavitation and noise while significantly enhancing thrust and greatly improving propeller efficiency. Summary of the Invention

[0005] This invention provides a ship propeller-driven annular anti-vortex booster energy-saving device to solve the problem that conventional energy-saving devices in the prior art do not significantly improve propeller propulsion performance.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A ship propeller-assisted vortex-eliminating and energy-saving device includes: a cone on the propeller shaft, vortex-eliminating fins, a duct, rectifier blades inside the duct, and a rear guide vane. The small-diameter end of the cone is fixedly connected to a propeller hub. Several vortex-eliminating fins are arranged circumferentially around the cone and the hub. The rectifier blades and the rear guide vane are installed inside the duct. The blades installed on the duct are annular blades. The hub end is flush with one end face of the duct, and the cone end extends a length L beyond the other end face of the duct. The large-end surface of the frustum of the energy-saving device is connected to the rear end surface of the propeller hub.

[0007] Furthermore, as a preferred embodiment, the anti-vortex fins are tapered arc-shaped plates, and their number is adapted to the number of propellers.

[0008] Furthermore, as a preferred embodiment, the anti-vortex fins are arranged in a tapered structure along the circumference, and their shape is a NACA6612 airfoil with a radius of R1, and the number of anti-vortex fins is 5.

[0009] Furthermore, as a preferred embodiment, the radius R1 of the anti-vortex fin NACA6612 airfoil shape is 1 / 3 of the propeller diameter, and the angle β corresponding to the side of the fairing fin contacting the hub surface is 25 to 45 degrees. Furthermore, as a preferred embodiment, the rectifier blade is installed inside the duct and its shape is a tapered arc-shaped sheet with a radius of R1 of NACA6612, and the number of rectifier blades is 5.

[0010] Furthermore, as a preferred embodiment, the rear guide vane is an asymmetric airfoil with a radius of R1, and the number of rear guide vanes is adapted to the number of propeller blades, which is 5 blades.

[0011] Furthermore, as a preferred embodiment, the annular blade has an airfoil-shaped cross-section, is annular in shape, and has 2 to 6 blades.

[0012] Furthermore, as a preferred embodiment, the number of annular blades is four.

[0013] Furthermore, as a preferred embodiment, the length of the annular blade is 1.1 to 1.4 times the propeller radius. The annular blade has an upper end and a lower end that are respectively connected to the duct. The upper end and the lower end extend outward from the side of the propeller shaft and connect to the outside of the duct to form a perforated ring on the duct. There are 4 annular blades, and the plurality of annular blades are arranged on the side of the duct around the central axis of the duct.

[0014] Furthermore, as a preferred embodiment, the length of the duct is 0.8 to 1.2 times the length of the propeller hub, the outer diameter of the duct is equal to the surface diameter of the rear end of the propeller hub, and the inner diameter of the duct is 0.7 to 0.8 times the surface diameter of the rear end of the propeller hub.

[0015] Furthermore, as a preferred embodiment, the length of the cone is 0.5 to 0.7 times the length of the propeller hub, the angle between the large-diameter end surface of the cone and the generatrix is ​​30 to 60°, and the radius of the large-diameter end surface of the cone is equal to the radius of the propeller hub.

[0016] Furthermore, as a preferred embodiment, the anti-vortex fin 2, the rectifier blade 3, and the rear guide blade 5 are arranged in series and installed inside the duct to form a multi-stage energy recovery and wake correction structure design.

[0017] Compared with the prior art, the beneficial effects of the present invention are: The present invention discloses a ship propeller-driven annular vortex-eliminating and energy-saving device, which consists of a cone, multiple vortex-eliminating fins, multiple flow-rectifying fins, a rear guide vane, a duct, and multiple annular blades. The vortex-eliminating fins are evenly arranged circumferentially on the surface of the propeller hub, and the annular blades are also evenly arranged circumferentially on the surface of the duct. The device has a high degree of integration and can be modularly produced, which greatly reduces costs.

[0018] This invention features an innovative structural design and simple installation. It can be directly mounted on the propeller hub, rotating synchronously with the propeller to optimize water flow. Compared to conventional energy-saving devices, this rear-mounted annular vortex-eliminating booster energy-saving device more effectively diffuses or even eliminates hub vortex phenomena and achieves multi-stage recovery of energy losses caused by hub vortices. Furthermore, the perforated design on the annular hydrofoil allows for smooth water flow, improving water discharge efficiency and reducing cavitation formation. This not only reduces noise generated during the operation of the energy-saving device but also reduces its drag. Simultaneously, this design reduces the propeller's total torque, achieving energy savings and providing a significant additional thrust, thereby improving the propeller's operating efficiency.

[0019] When the advance coefficient is 0.1~0.6, the propeller's propulsion efficiency is increased by 6.25%, the wake distribution behind the propeller is more uniform, and the tip vortex and hub vortex are significantly reduced. Attached Figure Description

[0020] The features and advantages of the invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the drawings: Figure 1 This is a front view of a specific embodiment of the present invention; Figure 2 According to specific embodiments of the present invention Figure 1 Working principle diagram; Figure 3 This is a rear view of a specific embodiment of the present invention; Figure 4 This is a structural disassembly view of a specific embodiment of the present invention; Figure 5This is a schematic diagram of the water flow through the cone to the blades inside the guide tube in a specific embodiment of the present invention; Figure 6 This is a diagram illustrating the water flow effect from the cone to the blades inside the guide tube in a specific embodiment of the present invention. Figure 7 This is a diagram illustrating the weakening effect of tip vortex and hub vortex on the annular blade after flowing through the propeller in a specific embodiment of the present invention. Table 1 shows the energy-saving effects in specific embodiments of the present invention; Figure 8 This is a front axial side view in a specific embodiment of the present invention; Figure 9 This is a rear axial side view in a specific embodiment of the present invention. Detailed Implementation To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] When a ship is sailing, the high-speed wake region behind the propeller hub experiences significant energy dissipation during propeller rotation, negatively impacting propulsion efficiency. Simultaneously, a strong rotating hub vortex is generated behind the propeller hub, creating a low-pressure area that further reduces propeller efficiency. This phenomenon is more pronounced in large ships, especially those with high pitch. To address this hub vortex effect, this invention designs a ring-shaped vortex-eliminating and thrust-boosting energy-saving device behind the propeller, aiming to overcome the aforementioned adverse effects and optimize propeller thrust performance. This patent utilizes the rotating water flow behind the propeller to generate a boosting effect, enhancing propeller thrust performance while simultaneously reducing and eliminating hub and tip vortices, thus reducing negative pressure, noise, and vibration, thereby improving the overall propeller efficiency.

[0022] Please see the appendix Figure 1-9 As shown, a ship propeller-supported annular vortex-eliminating and energy-saving device includes a cone 1 and a duct 4. Several annular blades 6 are evenly arranged on the outer circumference of the duct 4. A propeller hub is fixedly connected to the small-diameter end of the cone 1. Several vortex-eliminating fins 2 are evenly fixedly connected to the circumferential surfaces of the cone 1 and the propeller hub. A flow-rectifying blade 3 and a rear guide vane 5 are inserted into the duct 4. The connected propeller hub is flush with the end face of the duct 4. The large-end surface of the cone 1 is connected to the rear end surface of the propeller hub.

[0023] The vortex-eliminating fin 2 is an airfoil-shaped sheet, the number of which is adapted to the number of propeller blades. The fin 2 can change the flow field at the root of the propeller, straighten the wake, and eliminate hub vortices.

[0024] In this embodiment, the vortex-suppressing fin 2 is an airfoil with a radius of R1 = 0.5 to 0.7 times the propeller diameter. There are 5 vortex-suppressing fins 2, and the angle range corresponding to the side of the vortex-suppressing fin 2 in contact with the rotor hub surface is 25 to 45 degrees.

[0025] In this embodiment, the rectifier blade 3 is a tapered arc-shaped blade with a radius of R1 = 0.5~0.7 times the propeller diameter, and the number of rectifier blades 3 is 5.

[0026] In this embodiment, the rear guide vane 5 is an asymmetric airfoil with a radius R2 = 0.5 to 0.7 times the diameter of the propeller.

[0027] The annular blades have a symmetrical airfoil shape in cross-section and have a number of 2 to 6 blades.

[0028] In this embodiment, there are four annular blades 6. The hydrofoil has four annular blades 6 with the same structure distributed circumferentially on the surface of the duct 4, wherein the included angle between any two blades 6 is equal. The length of the annular blade 6 is 1.1 to 1.4 times the radius of the propeller 0. The annular blade of this length can better capture the rotating water flow behind the propeller 0, and can also use the rotational energy lost by the propeller 0 wake to achieve its own free rotation, thereby achieving energy saving by providing additional thrust.

[0029] In this embodiment, the chord length of the cross section of the annular blade 6 at the intersection with the surface of the guide tube 4 is 0.6 to 0.8 times the circumference of the rear end of the propeller hub 0.

[0030] The length of the duct 4 is 0.8 to 1.2 times the length of the propeller hub, and the diameter of the duct 4 is equal to the rear end of the propeller hub.

[0031] The length of the cone 1 is 0.5 to 0.7 times the length of the propeller hub, and the angle θ between the diameter end surface of the cone 1 and the generatrix is ​​25 to 45 degrees.

[0032] In this embodiment, the cone 1 is connected to one end of the propeller hub, and its diameter is equal to the diameter of the propeller hub.

[0033] The energy-saving annular anti-vortex booster device for propellers is installed at the stern 7 of the ship. This energy-saving device is located at the propeller shaft centerline 8 and is connected to the rear end of the propeller hub 0 via a cone 1. It can be welded and fixed, making installation convenient. Figure 2 , 5As shown in Figure 6, the rotating water flow after propeller 0 flows into cone 1. After the anti-vortex fins 2 eliminate vortices in the water flow, the water flow is introduced into the duct. As the water flows through the duct, the rectifier blades further correct the water flow. Then, the rear guide vanes further recover and rectify the water flow, so that the water flowing out of the duct has a converging and accelerating effect, thereby playing the role of diffusing hub vortices; Figure 2 , 7 As shown, the rotating water flow outside the duct area passes through the annular blade 6, driving the rotation of the blade 6 and boosting the propeller 0, thus improving the overall efficiency of the propeller 0. The annular blade 6 can guide more water flow through its special annular holes, pull in more water flow, recover as much wake energy as possible, and weaken the tip vortex at the blade tip.

[0034] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art will understand that any variations or substitutions that can be easily conceived without departing from the principles and spirit of the present invention should be considered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A post propeller annular vortex reducing booster type energy saving device of a ship characterized by, It includes a cone (1) and a guide tube (4) on the propeller shaft; the outer edge of the guide tube (4) is evenly provided with several annular blades (6) on the circumferential surface; the large diameter end of the cone (1) is fixedly connected to the propeller hub; the outer edge of the small diameter end of the cone (1) is provided with several anti-vortex fins (2) along the circumferential direction; the rectifier blades (3) and the rear guide blades (5) are installed inside the guide tube (4).

2. A post propeller annular vortex-damping booster type energy saving device of a ship according to claim 1, characterized in that, The anti-vortex fin (2) is an airfoil with a radius of R1 and an airfoil shape of NACA6612. The number of anti-vortex fins (2) is adapted to the number of propeller blades.

3. A post propeller annular vortex reducing booster type energy saving device for a marine vessel according to claim 1, characterized in that, The rectifier blade (3) is a tapered arc-shaped plate that is inserted into the guide tube (4).

4. A post propeller annular vortex-damping booster type energy saving device of a ship according to claim 2, characterized in that, The radius R1 of the airfoil shape of the anti-vortex fin (2) is 1 / 3 of the diameter of the propeller (0), and the angle range corresponding to the side of the anti-vortex fin (2) in contact with the hub surface is 25 to 45 degrees.

5. A post propeller annular vortex reducing booster type energy saving device for a marine vessel according to claim 1, characterized in that, The rear guide vane (5) is an asymmetric airfoil with a radius of R2 and an airfoil shape of NACA6612. The number of rear guide vanes (5) is adapted to the number of propeller blades. The vortex-suppressing fins (2), the flow-rectifying blades (3), and the rear guide vanes (5) are arranged in series and installed inside the duct as a multi-stage energy recovery and wake correction structure design.

6. A post propeller annular vortex reducing booster type energy saving device for a marine vessel according to claim 1, characterized in that, The annular blade (6) has a symmetrical airfoil profile, is annular in shape, and has 2 to 6 blades.

7. A post propeller annular vortex reducing booster type energy saving device for a marine vessel according to claim 1, characterized in that, The length of the annular blade (6) is 1.1 to 1.4 times the radius of the propeller (0). The annular blade (6) has an upper end and a lower end that are respectively connected to the guide tube. The upper end and the lower end extend outward from the side of the propeller shaft and are connected to the outside of the guide tube to form a perforated ring on the guide tube. There are multiple annular blades, and the multiple blades are arranged on the guide tube around the central axis of the guide tube.

8. A ring propeller post vortex elimination booster energy saving device of a marine vessel according to claim 1, characterized in that, The length of the duct (4) is 8 to 2 times the length of the propeller (0) hub, the outer diameter of the duct (4) is equal to the surface diameter of the rear end of the propeller (0) hub, and the inner diameter of the duct (4) is 7 to 8 times the surface diameter of the rear end of the propeller (0) hub.

9. A post propeller annular vortex reducing booster energy saving device for a marine vessel as claimed in claim 1 wherein, The length of the cone (1) is 5 to 7 times the length of the propeller (0) hub, the angle between the large diameter end surface of the cone (1) and the generatrix is ​​30 to 60 degrees, and the radius of the large diameter end surface of the cone (1) is equal to the radius of the propeller (0) hub.

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