Energy-saving appendage device behind ship propeller

Abstract

The invention discloses an energy-saving device behind a ship propeller. Belongs to the technical field of ship propulsion system energy conservation. The device comprises a cone assembled with a propeller shaft, positioning fins used for positioning and flow guiding, a small guide pipe and a bent angle type blade. Energy conservation and efficiency improvement are achieved through the following technologies that firstly, pressure distribution of a ship stern flow field is actively adjusted, and the downstream flow field form of a propeller is optimized; 2, stern flow circumferential rotation energy generated in the operation process of the propeller is efficiently recycled, and disordered energy is converted into effective propulsion energy; thirdly, various vortexes generated in the stern flow field are attenuated or segmented, and vortex resistance is reduced; 4, through the flow field optimization effect, additional thrust is provided for the ship while resistance is reduced; in addition, the device further effectively reduces noise in the operation process of the propeller, inhibits generation and development of the cavitation phenomenon, reduces erosion damage of cavitation to propeller blades, and achieves the dual technical purposes of efficiency improvement and long-term energy-saving operation of a ship propulsion system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of ship propulsion system energy saving, and relates to a ship propeller post energy saving appendage device. BACKGROUND

[0002] The role of ships as core marine transportation tools is increasingly prominent, but the problems of high consumption of mineral energy and high emission of greenhouse gases associated with ships are also increasingly prominent. New rules for ship energy saving and emission reduction, such as the mandatory implementation of EEXI index, bring opportunities to the industry while also posing challenges; in order to achieve the goal of ship energy saving and emission reduction, a large amount of research has been carried out on the path of ship energy saving.

[0003] Although conventional hydrodynamic energy saving devices have been widely used in commercial ships, they can recover part of the hub vortex energy loss and generate propulsion by rotating water flow behind the propeller, but the effect of enhancing the propeller thrust is not significant, and there are obvious limitations. SUMMARY

[0004] The purpose of the present application is to provide a ship propeller post energy saving appendage device that can solve the problem of poor improvement effect of conventional energy saving devices on propeller propulsion performance.

[0005] The technical solution of the present application is: a ship propeller post energy saving appendage device, comprising a conical body (including a bearing) and a small conduit in the shape of a ring, a plurality of curved angle blades are arranged in an array along the circumference of the outer edge of the small conduit; the blades are installed on the conduit and adopt a curved angle structure;

[0006] The large diameter end of the conical body is connected to the propeller shaft through the installed bearing, and the bearing is connected to the propeller shaft and the conical body at both ends; the propeller shaft connection end is flush with one end face of the small conduit, and the conical body connection end extends into the other end face of the conduit.

[0007] Further, a plurality of positioning fins are arranged along the circumference of the outer edge of the conical body, the positioning fins are trapezoidal pieces, the upper side of which is adapted to the necking degree of the small conduit, the lower side of which is attached to the conical body, and the positioning fins are installed between the two.

[0008] Further, the length of the positioning fins is 1 / 2 of the length of the conical body, and the axial deviation angle of the positioning fins relative to the axis is in the range of 0-20°.

[0009] Further, the curved angle blade is composed of a blade and a curved angle.

[0010] Further, the bending direction of the curved angle is consistent with the rotation direction of the propeller; the bending angle is between 20-60°, and the length of the bending section is where D is the diameter of the matched propeller.

[0011] Further, the cross section of the curved corner blade is an asymmetric airfoil, the number of the curved corner blade is 8-12, preferably, the number of the curved corner blade is 10; and the curved corner blade has a lower end connected with the duct, extends outward from the root, and forms a curved corner at the upper end.

[0012] Further, the length of the curved corner blade is 0.6-0.7 times of D.

[0013] Further, the length of the small duct is 0.3-0.5D, the inner diameter of the small duct is 0.22-0.25D, and the outer diameter of the small duct is larger than the surface diameter of the rear end of the propeller shaft.

[0014] Further, the length of the cone is 0.2-0.4D; the cone has the same angular velocity as the curved corner blade and rotates freely with the flow behind the propeller.

[0015] Further, the number of the positioning fins is matched with the number of the propeller blades; the positioning fins are arranged in the circumferential direction, and the number of the positioning fins is 5.

[0016] When the ship sails, the rotation of the propeller will cause the energy dissipation of the high-speed wake zone of the disc surface behind the propeller to be serious, and a strong rotating hub vortex is formed behind the hub, which is accompanied by a low pressure area, and both of them reduce the propeller propulsion efficiency; this phenomenon is more significant in large ships, especially in high pitch ships; in order to deal with the hub vortex effect, the energy saving device behind the propeller of the ship is designed, by installing the device behind the propeller, the rotating flow behind the propeller can be used to generate a boost effect to improve the propeller thrust performance, and the hub vortex and tip vortex behind the propeller can be reduced and eliminated, the negative pressure, noise and vibration are reduced, and finally the overall working efficiency of the propeller is improved, and the above adverse effects are overcome.

[0017] Advantages: compared with the prior art, the present application has the following obvious characteristics: 1, the present application is composed of a cone, a bearing, a plurality of positioning fins, a small duct and a plurality of curved corner blades; the positioning fins are uniformly arranged on the surface of the cone, which has the dual functions of eliminating the hub vortex and providing the installation basis for the duct and the curved corner blade; the curved corner blades are uniformly arranged on the surface of the small duct; the device has high integration degree, can realize modular production, and can significantly reduce the manufacturing cost; 2, the device is easy to install and can be directly arranged on the propeller hub and rotate with the flow to optimize the water flow; compared with the conventional energy saving device, the propeller post vortex elimination and boost energy saving device can more efficiently diffuse or even eliminate the hub vortex, realize multi-stage recovery of hub vortex energy loss; at the same time, the device can reduce the cavitation generation, which can reduce the noise of the device running; in addition, the device can also reduce the total torque of the propeller to realize energy saving and provide significant additional thrust, and finally improve the working efficiency of the propeller. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1It is the overall structure schematic diagram of the present application;

[0019] Figure 2 It is the structure split diagram of the present application;

[0020] Figure 3 It is the front view of the present application;

[0021] Figure 4 It is the rear view of the present application;

[0022] Figure 5 It is the installation effect diagram of the present application;

[0023] Wherein, 1 is a cone, 2 is a positioning fin, 3 is a small conduit, 4 is a curved corner blade, 5 is a curved corner, and 6 is a bearing. DETAILED DESCRIPTION

[0024] The specific technical solutions of the present application will be further described in detail below in combination with specific examples.

[0025] As shown in the figure, the ship propeller post energy-saving device provided by the present application comprises a cone 1 (containing a bearing) and a small conduit 3; a plurality of curved corner blades 4 are evenly installed on the outer circumferential surface of the small conduit 3, the large diameter end of the cone 1 is connected to a propeller shaft through a bearing 6, and a plurality of positioning fins 2 are fixedly installed on the circumferential surface of the cone 1, wherein the connected propeller shaft is flush with the end surface of the small conduit 3, and the connected cone 1 extends into the other end (i.e. the width of the water inlet) of the small conduit 3.

[0026] The positioning fin 2 is a trapezoidal sheet body, the number of which is adapted to the number of propeller blades, and the positioning fin 2 can change the flow field of the target propeller root, straighten the tail flow, and eliminate the propeller hub vortex.

[0027] In this embodiment, the positioning fin 2 is a trapezoidal sheet body, the number of the positioning fin 2 is 5, and the axial deviation angle of the positioning fin 2 relative to the axis ranges from 0 to 20°.

[0028] The curved corner blade 4 has a cross section in the form of a non-symmetrical airfoil, and the number of the curved corner blade 4 is 10.

[0029] In this embodiment, the number of the curved corner blade 4 is 10, which is evenly distributed circumferentially on the surface of the small conduit 3 (the included angle between any two blades is equal); the length of the curved corner blade 4 is designed to be 0.6-0.7 times the diameter of the target propeller, and this length design can more efficiently capture the rotating water flow behind the propeller, and realize self-rotation by utilizing the rotational loss energy of the propeller tail flow, thereby achieving the energy-saving effect through providing additional thrust.

[0030] In this embodiment, the cross-sectional chord length of the curved corner blade 4 at the intersection with the surface of the small conduit 3 is 0.3-0.5 times the circumference of the rear end of the propeller shaft.

[0031] The length of the small conduit 3 is 0.3-0.5D, and the outer diameter of the small conduit 3 at the connection side with the propeller shaft is slightly larger than the surface diameter of the rear end of the target propeller shaft.

[0032] The length of the cone 1 is 0.2-0.4D, and the diameter end surface of the cone 1 coincides with the axis.

[0033] In this embodiment, the cone 1 is connected to one end of the propeller shaft, and the diameter of the cone 1 is slightly larger than the diameter of the propeller shaft.

[0034] The ship propeller rear energy-saving device is installed at the tail of the ship body, the energy-saving device is located at the propeller shaft center line, and the cone 1 is connected with the rear end bearing of the propeller hub through the cone 1, so that installation is convenient.

Claims

1. A ship propeller-driven energy-saving appendage device, characterized in that, It includes a cone (1) and a small conduit (3) in the shape of a ring. Several curved blades (4) are arranged in an array along the circumference of the outer edge of the small conduit (3). The large-diameter end of the cone (1) is connected to the propeller shaft via an installed bearing (6), and the two ends of the bearing (6) are respectively connected to the propeller shaft and the cone (1).

2. The ship propeller-following energy-saving appendage device according to claim 1, characterized in that, Several positioning fins (2) are installed circumferentially on the outer edge of the cone (1). The positioning fins (2) are trapezoidal plates, the upper side of which is adapted to the necking degree of the small guide tube (3), the lower side of which is attached to the cone (1) and installed between the two.

3. The ship propeller-following energy-saving appendage device according to claim 2, characterized in that, The length of the positioning fin (2) is half the length of the cone (1), and its axial deviation angle relative to the axis ranges from 0 to 20°.

4. The ship propeller-side energy-saving appendage device according to claim 1, characterized in that, The curved blade (4) consists of a blade and a curved angle (5).

5. The ship propeller-side energy-saving appendage device according to claim 4, characterized in that, The bending direction of the bend (5) is consistent with the rotation direction of the propeller; Its bending angle is between 20° and 60°, and the length of the bending section is... In the formula, D is the diameter of the matching propeller.

6. The ship propeller-side energy-saving appendage device according to claim 4, characterized in that, The curved blade (4) has an asymmetrical airfoil profile and has 8 to 12 blades; and has a lower end connected to the duct, extending outward from its root and forming a bend at the upper end.

7. The ship propeller-side energy-saving appendage device according to claim 5, characterized in that, The length of the curved blade (4) is 0.6 to 0.7 times D.

8. The ship propeller-side energy-saving appendage device according to claim 5, characterized in that, The length of the small conduit (3) is 0.3 to 0.5D, its inner diameter is 0.22 to 0.25D, and its outer diameter is larger than the surface diameter of the rear end of the target propeller shaft.

9. The ship propeller-side energy-saving appendage device according to claim 5, characterized in that, The length of the cone (1) is 0.2 to 0.4D; the cone (1) has the same angular velocity as the curved blade (4).

10. The ship propeller-side energy-saving appendage device according to claim 2, characterized in that, The number of positioning fins (2) is adapted to the number of propeller blades.

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