Low vibration and high efficiency double duct propeller front energy saving device

Abstract

The present invention provides a low-vibration and high-efficiency double-duct propeller front energy-saving device, comprising two first radial guide vanes, a first arc duct, a second arc duct and a plurality of second radial guide vanes: the first radial guide vane is arranged along the radial direction of a stern shaft and the first end of the first radial guide vane is fixed to the periphery of the stern shaft; the second radial guide vane is arranged along the radial direction of the stern shaft and is located between the two first radial guide vanes, the second radial guide vane is connected to the periphery of the stern shaft or connected to the first radial guide vane through the first arc duct and / or the second arc duct; the first arc duct and the second arc duct are respectively connected to the first radial guide vane and the second radial guide vane or connected to at least two second radial guide vanes. A low-vibration and high-efficiency double-duct propeller front energy-saving device of the present invention can make full use of the hydrodynamic characteristics of the wake field at the stern of a ship, improve the energy-saving effect, and greatly increase the structural reliability, reducing the risk of structural damage and resonance.

Description

Technical Field

[0001] The invention relates to the field of propeller front energy-saving devices, and in particular to a low-vibration and high-efficiency double-duct propeller front energy-saving device. Background Art

[0002] In the current shipping industry, shipowners have increasingly stringent requirements for fuel consumption, and ship emissions are becoming increasingly low-carbon and environmentally friendly. More and more newly built and renovated ships are installing propeller-front pre-swirl energy-saving ducts. The propeller-front pre-swirl energy-saving ducts currently on the market mainly include only a few pre-swirl guide vanes and a combination of several pre-swirl guide vanes plus a fan-shaped duct. The above two forms fail to fully utilize the characteristics of the wake field at the stern of the ship to improve the energy-saving effect. With the emergence of large-diameter propellers, the guide vane length is too long, and there are structural strength and safety issues. At the same time, the vibration performance of the energy-saving device has also deteriorated, and it is more likely to resonate with the main hull vibration source and cause damage. In addition, the excessive vibration amplitude during the free vibration of the guide vane will also affect the energy-saving effect of the energy-saving duct.

[0003] At present, the pre-rotation energy-saving ducts in front of the propeller mainly include: a combination of several pre-rotation guide vanes and several pre-rotation guide vanes plus a fan-shaped duct. For example, in the form of only guide vanes, the number of guide vanes can be 3, 4, 5, etc., depending on the flow field at the rear of the ship. The combination of guide vanes and a fan-shaped duct is the most common product form on the market. The number of guide vanes is also not fixed, but its form is various: the fan-shaped duct can be located within the length range of the guide vane or at the top of the guide vane. The duct can be either a partial arc or a full circle.

[0004] The existing propeller pre-swirl energy-saving duct without a fan-shaped duct or with a fan-shaped duct cannot fully utilize the wake field at the stern of the ship, and its energy-saving potential has not been fully utilized.

[0005] The guide vane is a slender structure welded to the stern hull. For energy-saving devices without fan-shaped ducts, a single guide vane is a cantilever beam with only one fulcrum, which has a high risk of structural damage and resonance. Relatively speaking, a combination of a fan-shaped duct and a guide vane has greatly improved the above aspects, but now large-diameter propellers are increasingly used on large ships, and the length of the guide vanes has also increased, resulting in the guide vanes becoming more and more slender, and there is still a high risk of structural damage and resonance. Summary of the invention

[0006] In view of the deficiencies in the above-mentioned prior art, the present invention provides a low-vibration and high-efficiency double-ducted propeller front energy-saving device, which can fully utilize the hydrodynamic characteristics of the wake field at the stern of the ship to improve the energy-saving effect. Moreover, due to the presence of the double ducts, the structural reliability of the entire energy-saving device is greatly increased, and the risk of structural damage and resonance of the energy-saving device is greatly reduced.

[0007] In order to achieve the above-mentioned object, the present invention provides a low-vibration and high-efficiency double-duct propeller front energy-saving device, comprising two first radial guide vanes, a first arc duct, a second arc duct and a plurality of second radial guide vanes; or only comprising two first radial guide vanes, a first arc duct and a second arc duct; the first radial guide vanes are arranged along the radial direction of a stern shaft and the first end of the first radial guide vane is fixed to the periphery of the stern shaft;

[0008] When the second radial guide vane is included, the second radial guide vane is arranged along the radial direction of the stern shaft and is located between the two first radial guide vanes, the second radial guide vane is connected to the periphery of the stern shaft or is connected to the first radial guide vane through the first circular arc duct and / or the second circular arc duct; the first circular arc duct connects the first radial guide vane and the second radial guide vane or connects at least two of the second radial guide vanes; the second circular arc duct connects the first radial guide vane and the second radial guide vane or connects at least two of the second radial guide vanes; the distance between the second circular arc duct and the stern shaft is greater than the distance between the first circular arc duct and the stern shaft.

[0009] Preferably, when only two first radial guide vanes, the first circular arc duct and the second circular arc duct are included, the first circular arc duct is fixed between adjacent side portions of the two first radial guide vanes, and the second circular arc duct is fixed between adjacent side portions of the two first radial guide vanes, between a side portion of one first radial guide vane and the second end of another first radial guide vane, or between the second ends of two first radial guide vanes.

[0010] Preferably, when the second radial guide vanes are included, the number of the second radial guide vanes is 1 to 6.

[0011] Preferably, the length of the first radial guide vane is equal to the distance from the first circular arc duct to the stern shaft, equal to the distance from the second circular arc duct to the stern shaft, or greater than the distance from the second circular arc duct to the stern shaft.

[0012] Preferably, the first end of the second radial guide vane is connected to the periphery of the stern shaft, the first circular arc duct or the second circular arc duct; the second end of the second radial guide vane is connected to the first circular arc duct, the second circular arc duct or extends outside the second circular arc duct.

[0013] Preferably, the first end of the first circular arc duct is connected to the side of the first radial guide vane, the second end of the first radial guide vane, the side of the second radial guide vane, the first end of the second radial guide vane, or the second end of the second radial guide vane; the second end of the first circular arc duct is connected to the side of the second radial guide vane, the first end of the second radial guide vane, the second end of the second radial guide vane, the side of the first radial guide vane, or the second end of the first radial guide vane.

[0014] Preferably, the first end of the second circular arc duct is connected to the side of the first radial guide vane, the second end of the first radial guide vane, the side of the second radial guide vane, the first end of the second radial guide vane, or the second end of the second radial guide vane; the second end of the second circular arc duct is connected to the side of the second radial guide vane, the first end of the second radial guide vane, the second end of the second radial guide vane, the side of the first radial guide vane, or the second end of the first radial guide vane.

[0015] The present invention adopts the above technical solution, so it has the following beneficial effects:

[0016] Through the cooperation of the first radial guide vane, the first arc duct, the second arc duct and the second radial guide vane, the tail wake flow field can be better rectified to improve the energy saving effect. The double duct form greatly reduces the risk of structural damage and resonance of the energy saving device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a low-vibration and high-efficiency double-ducted propeller front energy-saving device in a three-blade form according to an embodiment of the present invention;

[0018] Figure 2 It is a structural schematic diagram of a low-vibration and high-efficiency double-ducted propeller front energy-saving device in a four-blade form according to an embodiment of the present invention;

[0019] Figure 3 It is a schematic structural diagram of the energy-saving device in front of a five-blade low-vibration and high-efficiency double-ducted propeller according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The following is based on the attached Figure 1 to Figure 3 , give the preferred embodiments of the present invention, and describe them in detail so that the functions and features of the present invention can be better understood.

[0021] See also Figure 1 A low-vibration, high-efficiency, double-ducted propeller front energy-saving device according to a first embodiment of the present invention comprises two first radial guide vanes 1, a first circular arc duct 2 and a second circular arc duct 3; the first radial guide vanes 1 are arranged along the radial direction of a stern shaft and the first end of the first radial guide vane 1 is fixed to the periphery of the stern shaft; the first circular arc duct 2 is fixed between adjacent side portions of the two first radial guide vanes 1, and the second circular arc duct 3 is fixed between adjacent side portions of the two first radial guide vanes 1, between a side portion of a first radial guide vane 1 and the second end of another first radial guide vane 1, or between the second ends of the two first radial guide vanes 1.

[0022] See also Figure 1The second embodiment of the present invention is a low-vibration and high-efficiency double-ducted propeller front energy-saving device, and its result is basically the same as that of the first embodiment, except that: there are also a plurality of second radial guide vanes 4:

[0023] The second radial guide vane 4 is arranged along the radial direction of the stern shaft and is located between the two first radial guide vanes 1. The second radial guide vane 4 is connected to the periphery of the stern shaft or is connected to the first radial guide vane 1 through the first circular arc duct 2 and / or the second circular arc duct 3; the first circular arc duct 2 connects the first radial guide vane 1 and the second radial guide vane 4 or connects at least two second radial guide vanes 4; the second circular arc duct 3 connects the first radial guide vane 1 and the second radial guide vane 4 or connects at least two second radial guide vanes 4; the distance between the second circular arc duct 3 and the stern shaft is greater than the distance between the first circular arc duct 2 and the stern shaft.

[0024] The number of the second radial guide vanes 4 is 1 to 6. Figure 2 The number of the second radial guide vanes is 2; Figure 3 The number of the second radial guide vanes is 3.

[0025] See also Figure 1 to Figure 3 The length of the first radial guide vane 1 is equal to the distance from the first circular arc duct 2 to the stern shaft, equal to the distance from the second circular arc duct 3 to the stern shaft, or greater than the distance from the second circular arc duct 3 to the stern shaft.

[0026] The first end of the second radial guide vane 4 is connected to the periphery of the stern shaft, the first arc duct 2 or the second arc duct 3 ; the second end of the second radial guide vane 4 is connected to the first arc duct 2 , the second arc duct 3 or extends outside the second arc duct 3 .

[0027] The first end of the first circular arc duct 2 is connected to the side of the first radial guide vane 1, the second end of the first radial guide vane 1, the side of the second radial guide vane 4, the first end of the second radial guide vane 4, or the second end of the second radial guide vane 4; the second end of the first circular arc duct 2 is connected to the side of the second radial guide vane 4, the first end of the second radial guide vane 4, the second end of the second radial guide vane 4, the side of the first radial guide vane 1, or the second end of the first radial guide vane 1.

[0028] The first end of the second circular arc duct 3 is connected to the side of the first radial guide vane 1, the second end of the first radial guide vane 1, the side of the second radial guide vane 4, the first end of the second radial guide vane 4, or the second end of the second radial guide vane 4; the second end of the second circular arc duct 3 is connected to the side of the second radial guide vane 4, the first end of the second radial guide vane 4, the second end of the second radial guide vane 4, the side of the first radial guide vane 1, or the second end of the first radial guide vane 1.

[0029] A low-vibration and high-efficiency double-ducted propeller front energy-saving device in an embodiment of the present invention can fully utilize the hydrodynamic characteristics of the wake field at the stern of the ship to improve the energy-saving effect. Moreover, due to the presence of the double ducts, the structural reliability of the entire energy-saving device is greatly increased, and the risk of structural damage and resonance of the energy-saving device is greatly reduced.

[0030] According to CFD numerical simulation, under self-propelled state, the hydrodynamic energy saving effect is improved by >0.2% compared with the existing single-duct energy-saving device. According to finite element numerical simulation, under self-propelled state, the structural strength is greatly improved compared with the existing single-duct energy-saving device, and the structural vibration performance is greatly improved.

[0031] The present invention is described in detail above in conjunction with the embodiments of the accompanying drawings. A person skilled in the art can make various variations of the present invention according to the above description. Therefore, certain details in the embodiments should not constitute a limitation of the present invention, and the scope of protection of the present invention shall be defined by the scope of the attached claims.

Claims

1. A low-vibration and high-efficiency double-ducted propeller front energy-saving device, characterized in that: It includes two first radial guide vanes, a first circular arc conduit, a second circular arc conduit and a plurality of second radial guide vanes; or it only includes two first radial guide vanes, a first circular arc conduit and a second circular arc conduit; When the second radial guide vane is included, the second radial guide vane is arranged along the radial direction of the stern shaft and is located between the two first radial guide vanes, and the second radial guide vane is connected to the periphery of the stern shaft or connected to the first radial guide vane through the first circular arc duct and / or the second circular arc duct; The first circular arc duct connects the first radial guide vane and the second radial guide vane or connects at least two of the second radial guide vanes; the second circular arc duct connects the first radial guide vane and the second radial guide vane or connects at least two of the second radial guide vanes; the distance between the second circular arc duct and the stern shaft is greater than the distance between the first circular arc duct and the stern shaft; When only two first radial guide vanes, the first arc duct and the second arc duct are included, the first arc duct is fixed between adjacent side portions of the two first radial guide vanes, and the second arc duct is fixed between adjacent side portions of the two first radial guide vanes, between a side portion of one first radial guide vane and the second end of another first radial guide vane, or between the second ends of two first radial guide vanes; The first radial guide vane is arranged along the radial direction of a stern shaft, and a first end of the first radial guide vane is fixed to the periphery of the stern shaft.

2. The low-vibration and high-efficiency double-ducted propeller front energy-saving device according to claim 1 is characterized in that: When the second radial guide vanes are included, the number of the second radial guide vanes is 1 to 6.

3. The low-vibration and high-efficiency double-ducted propeller front energy-saving device according to claim 2 is characterized in that: The length of the first radial guide vane is equal to the distance from the first circular arc duct to the stern shaft, equal to the distance from the second circular arc duct to the stern shaft, or greater than the distance from the second circular arc duct to the stern shaft.

4. The low-vibration, high-efficiency, double-ducted propeller front energy-saving device according to claim 3, characterized in that: The first end of the second radial guide vane is connected to the periphery of the stern shaft, the first circular arc duct or the second circular arc duct; the second end of the second radial guide vane is connected to the first circular arc duct, the second circular arc duct or extends outside the second circular arc duct.

5. The low-vibration and high-efficiency double-ducted propeller front energy-saving device according to claim 4 is characterized in that: The first end of the first circular arc duct is connected to the side of the first radial guide vane, the second end of the first radial guide vane, the side of the second radial guide vane, the first end of the second radial guide vane, or the second end of the second radial guide vane; the second end of the first circular arc duct is connected to the side of the second radial guide vane, the first end of the second radial guide vane, the second end of the second radial guide vane, the side of the first radial guide vane, or the second end of the first radial guide vane.

6. The low-vibration and high-efficiency double-ducted propeller front energy-saving device according to claim 5 is characterized in that: The first end of the second circular arc duct is connected to the side of the first radial guide vane, the second end of the first radial guide vane, the side of the second radial guide vane, the first end of the second radial guide vane, or the second end of the second radial guide vane; the second end of the second circular arc duct is connected to the side of the second radial guide vane, the first end of the second radial guide vane, the second end of the second radial guide vane, the side of the first radial guide vane, or the second end of the first radial guide vane.

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