Distributed icebreaker bubble drag reduction system

Abstract

The application belongs to the technical field of icebreaking of ships, and provides a distributed icebreaking ship bubble drag reduction system arranged on an icebreaking ship, comprising: multiple sets of bubble generators, the multiple sets of bubble generators are distributed from a position close to a bow of the icebreaking ship to a middle of the icebreaking ship along a length direction of the icebreaking ship, each set of bubble generators comprises at least two air supply pipelines connected in communication, and each air supply pipeline forms a nozzle at a bilge of the icebreaking ship; multiple air compressors, each air compressor corresponds to each set of bubble generators, each air compressor is in communication with the air supply pipeline of the corresponding bubble generator, and the air compressor is used for delivering compressed air to the air supply pipeline; after the icebreaking ship enters water, the air compressor delivers compressed air to the air supply pipeline, and the compressed air is sprayed from the nozzle to generate bubbles to push away broken ice generated by icebreaking at a bow of the icebreaking ship; the application can reduce frictional resistance between the broken ice and a hull of the icebreaking ship, so that the icebreaking ship is reduced in drag.

Description

Technical Field

[0001] This invention relates to the field of ship icebreaking technology, and in particular to a distributed icebreaker bubble drag reduction system. Background Technology

[0002] The polar regions are rich in resources, and polar shipping routes can significantly shorten the voyage from Asia to Europe, leading to increasingly frequent economic activities in the polar regions. Whether icebreakers or vessels capable of autonomous navigation in the polar regions, they all need to possess a certain level of icebreaking capability. High-polar-class icebreakers typically have larger installed and propulsion power.

[0003] Existing bubble drag reduction systems for conventional waterways are not suitable for icebreakers because icebreakers travel at very low speeds when breaking ice, typically only 2-3 knots. Therefore, due to the very small resistance generated by the water, conventional bubble drag reduction systems have almost no effect on drag reduction. Summary of the Invention

[0004] This invention provides a distributed bubble drag reduction system for icebreakers to solve the technical problem that existing conventional bubble drag reduction systems are not applicable to icebreaker drag reduction.

[0005] This invention provides a distributed icebreaker bubble drag reduction system, installed on an icebreaker, comprising:

[0006] Multiple sets of bubble generators are distributed along the length of the icebreaker from near the bow to the middle of the ship. Each set of bubble generators includes at least two interconnected venting pipes, and each venting pipe forms a nozzle at the bilge of the icebreaker.

[0007] Multiple air compressors, each air compressor corresponding to each of the aforementioned bubble generators, each of the air compressors being connected to the ventilation pipeline of the corresponding bubble generator, and the air compressors being used to deliver compressed air to the ventilation pipelines;

[0008] After the icebreaker enters the water, the air compressor delivers compressed air to the ventilation pipeline and sprays it from the nozzle to generate bubbles, which push away the broken ice generated after the icebreaker's bow breaks through the ice.

[0009] In one embodiment of the present invention, the distance between the bubble generator closest to the bow of the icebreaker and the bow perpendicular of the icebreaker is greater than... ,in

[0010] ;

[0011] In the formula, E is the Young's modulus of the ice layer, with a value of 2.0 GPa, and H... ice ρ represents the ice layer thickness in meters (m), V is the Poisson's ratio of the ice layer (0.3), and ρ...w The density of seawater is expressed in kg / m³. 3 G is the acceleration due to gravity, with units of m / s². 2 .

[0012] In one embodiment of the present invention, the horizontal distance between adjacent bubble generators is L. pp / 20, where L pp This refers to the length between the ship's perpendiculars for an icebreaker.

[0013] In one embodiment of the present invention, the capacity of the air compressor corresponding to the bubble generator before the maximum width of the icebreaker is greater than the capacity of the air compressor corresponding to the other bubble generators.

[0014] In one embodiment of the present invention, the air compressor is located near the centerline of the icebreaker, and each of the air compressors is connected to the ventilation pipeline via a connecting pipeline.

[0015] In one embodiment of the present invention, each of the ventilation pipes is attached to the inner side of the icebreaker and the ventilation pipes of each group of bubble generators are symmetrical about the mid-longitudinal section of the icebreaker.

[0016] In one embodiment of the present invention, a check valve is provided in the venting pipeline near the nozzle, and a shut-off valve is provided in the venting pipeline near the air compressor.

[0017] In one embodiment of the present invention, the vertical distance between the nozzle and the ice layer is at least 2m.

[0018] In one embodiment of the present invention, the nozzle is a unidirectional nozzle.

[0019] In one embodiment of the present invention, the diameter of the nozzle is 80mm-120mm.

[0020] The beneficial effects of this invention are as follows: The distributed icebreaker bubble drag reduction system proposed in this invention forms nozzles in the bilge of the icebreaker through the ventilation pipelines of multiple sets of bubble generators. After the icebreaker breaks through the bow, compressed air is delivered to the ventilation pipelines by an air compressor and ejected from the nozzles to generate bubbles. The bubbles disperse from the bilge of the icebreaker to the sides, which can push away the broken ice generated after the icebreaker breaks through the bow, reduce the frictional resistance between the broken ice at the bow and the icebreaker hull, and thus achieve drag reduction of the icebreaker. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0022] In the attached diagram:

[0023] Figure 1 This is a first-view layout schematic diagram of a distributed icebreaker bubble drag reduction system provided in an embodiment of the present invention.

[0024] Figure 2 This is a second-view layout schematic diagram of a distributed icebreaker bubble drag reduction system provided in an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of the structure of a distributed icebreaker bubble drag reduction system provided in an embodiment of the present invention during the launching of an icebreaker;

[0026] Figure 4 for Figure 3 Enlarged structural diagram of region A in the middle;

[0027] Figure 5 This is a line graph corresponding to Table 1.

[0028] The attached figures are labeled as follows:

[0029] 1-Air compressor; 2-Ventilation line; 3-Nozzle; 4-Connecting line; 5-Check valve; 6-Stop valve; 7-Ice surface; 8-Bubble; 9-Broken ice; 10-Bin; 11-Platform deck. Detailed Implementation

[0030] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0031] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0032] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0033] It should be noted that, compared to conventional open-water vessels, icebreakers can save significantly more propulsion and engine power for the same drag reduction percentage. Therefore, research on drag reduction systems for polar icebreakers is essential. Currently, bubble drag reduction systems for conventional waterways typically place bubble generators at the hull bottom. Air compressors emit bubbles from the generators, forming a uniform air film at the hull bottom, reducing frictional resistance between the water flow and the hull. However, conventional bubble drag reduction systems are not suitable for icebreakers because icebreakers have very low icebreaking speeds and low water resistance; therefore, this drag reduction mechanism is not applicable to polar icebreakers. Existing technologies offer limited auxiliary icebreaking systems suitable for polar icebreakers. For example, combined bubble-assisted icebreaking systems utilize high-pressure bubbles, leveraging the high-speed jet and lagging energy of collapsing bubbles to damage the ice cap at the bow, thereby reducing icebreaking drag. However, this method requires a high-pressure air compressor to generate high-speed, high-pressure bubbles for icebreaking. Furthermore, the bubble generator is submerged, and the high-pressure bubbles need to travel a considerable distance to reach the ice surface. Under these conditions, achieving the desired impact and damage to the ice layer requires extremely high initial bubble velocity. Therefore, this bubble-assisted icebreaking drag reduction method places high demands on the icebreaker's configuration and energy consumption, consuming more resources while assisting icebreaking, resulting in a low drag reduction cost-effectiveness. Therefore, this invention provides a distributed icebreaker bubble drag reduction system suitable for icebreakers, achieving optimal drag reduction with the most economical configuration and improving drag reduction cost-effectiveness.

[0034] Please see Figures 1 to 4 This invention provides an exemplary distributed icebreaker bubble drag reduction system, which is installed on an icebreaker and includes:

[0035] Multiple sets of bubble generators are distributed along the length of the icebreaker from near the bow to the middle of the ship. Each set of bubble generators includes at least two interconnected ventilation pipes 2, and each ventilation pipe 2 forms a nozzle 3 in the bilge 10 of the icebreaker.

[0036] Multiple air compressors 1, each air compressor 1 is corresponding to each set of bubble generators, and each air compressor 1 is connected to the ventilation pipeline 2 of the corresponding bubble generator. The air compressor 1 is used to deliver compressed air to the ventilation pipeline 2.

[0037] After the icebreaker enters the water, the air compressor 1 delivers compressed air to the ventilation line 2 and sprays it out from the nozzle 3 to generate bubbles 8, which push away the broken ice 9 generated by the icebreaker's bow.

[0038] In the distributed icebreaker bubble drag reduction system provided in this embodiment, nozzles 3 are formed in the bilge 10 of the icebreaker through the ventilation pipes 2 of multiple bubble generators. After the icebreaker breaks the ice at the bow, compressed air is delivered to the ventilation pipes 2 by the air compressor 1 and ejected from the nozzles 3 to generate bubbles 8. The bubbles 8 are dispersed from the bilge 10 of the icebreaker to the side, which can push away the broken ice 9 generated after the icebreaker breaks the ice at the bow, reduce the frictional resistance between the broken ice 9 and the icebreaker hull, and thus achieve drag reduction of the icebreaker.

[0039] In this embodiment, the distance between the bubble generator closest to the bow of the icebreaker and the bow perpendicular of the icebreaker is greater than... ,in

[0040] ;

[0041] In the formula, E is the Young's modulus of the ice layer, with a value of 2 GPa, and H... ice ρ represents the ice layer thickness in meters (m), V is the Poisson's ratio of the ice layer (0.3), and ρ... w The density of seawater is expressed in kg / m³. 3 G is the acceleration due to gravity, with units of m / s². 2 .

[0042] In detail, the icebreaker's bow traveled over [a certain distance] through the ice. As the ice length increases, it begins to break and fracture, therefore... The ice layer that comes into contact with the icebreaker hull after the length of the icebreaker is mainly composed of broken ice (9). The bubble generator closest to the bow of the icebreaker is the first set of bubble generators. When the distance between the first set of bubble generators in the longitudinal direction of the icebreaker hull and the bow vertical line of the icebreaker is greater than... After the length is reached, the generated bubbles 8 can then push away the broken ice 9, thereby reducing the drag of the icebreaker.

[0043] In one embodiment, please refer to Table 1 and Figure 5 , in ρ w 1025 kg / m 3 G is 9.81 m / s 2 In this case, for different ice layer thicknesses, the corresponding The length is as follows:

[0044] Table 1. l corresponding to different ice thicknesses c length

[0045]

[0046] In the above embodiment, the horizontal distance between adjacent bubble generators is L. pp / 20, where L pp The length between the ship's perpendiculars is the distance between the bow and stern perpendiculars of the icebreaker. Specifically, starting from the first bubble generator, L... pp The bubble generator is positioned at a distance of 20 units from the rear, extending to the rear edge of the icebreaker's midships. As the icebreaker moves forward and the ice 9 sinks, the friction between the icebreaker and the ice 9 occurs primarily between the midships and the bow. This arrangement ensures that the bubbles 8 generated by the bubble generator are distributed throughout the vicinity of the midships, effectively pushing away the ice 9 and reducing the icebreaker's drag.

[0047] In some implementations, the capacity of the air compressor 1 corresponding to the first bubble generator and the bubble generators before the maximum width of the icebreaker is greater than the capacity of the air compressor 1 corresponding to the other bubble generators. Specifically, the hull section of the icebreaker before its maximum width will rub against most of the broken ice 9. For these areas where the broken ice 9 is severely compressed, the bubble generator needs to increase the air jet volume to ensure the best drag reduction effect. Therefore, the air compressor 1 corresponding to the first bubble generator and the bubble generators before the maximum width of the icebreaker needs to adopt a larger capacity air compressor 1 to meet the drag reduction requirements. The icebreaker's hull section, from its maximum width to midway, only rubs against the remaining ice floes 9. As the ice floes 9 come into contact with the hull ahead and sink, the remaining ice floes 9 decrease significantly. Therefore, for this area where the ice floes 9 exert relatively gentle pressure, the air compressor 1 corresponding to the bubble generator after the icebreaker's maximum width can be a smaller capacity air compressor 1. The minimum power configuration can meet the drag reduction requirements. In this way, the requirements for the icebreaker's own configuration can be reduced, and the best icebreaker drag reduction effect can be achieved with the most economical drag reduction configuration, thus improving the drag reduction cost-effectiveness.

[0048] Furthermore, the air compressor 1 is positioned close to the centerline of the icebreaker. Each air compressor 1 is connected to the ventilation pipe 2 via the connecting pipe 4. The arrangement of each air compressor 1 is close to the corresponding bubble generator in the longitudinal direction of the icebreaker hull. This arrangement allows the air compressor 1 to be located between the two ventilation pipes 2, resulting in a shorter length of the ventilation pipes 2 and higher efficiency in generating bubbles 8.

[0049] It is worth noting that each ventilation pipe 2 is attached to the inner side of the icebreaker, and the ventilation pipes 2 of each group of bubble generators are symmetrical about the longitudinal section of the icebreaker. In this embodiment, the air compressor 1 can be installed on the platform deck 11 of the icebreaker, and the ventilation pipes 2 are arranged on the side of the icebreaker. Since the two ventilation pipes 2 of each group of bubble generators are symmetrically arranged, the stroke of the air compressor 1 to deliver compressed air to the nozzles 3 of the two ventilation pipes 2 is similar, ensuring that the amount of bubbles sprayed on both sides is similar, and ensuring that the drag reduction effect on both sides of the bilge 10 of the icebreaker is similar.

[0050] In some embodiments, a check valve 5 is provided in the venting line 2 near the nozzle 3, and a shut-off valve 6 is provided in the venting line 2 near the air compressor 1. Specifically, the check valve 5 can prevent water from flowing back into the venting line 2 from the nozzle 3 when the icebreaker is launched, and the shut-off valve 6 can control the opening and closing of the venting line 2.

[0051] In this embodiment, the vertical distance between the nozzle 3 and the ice layer is at least 2m. The vertical position of the nozzle 3 needs to take into account the minimum icebreaking draft and ice layer thickness, and ensure that the distance between the first set of bubble generators and the first vertical line of the icebreaker is greater than... Under the premise that the bubbles 8 generated by the nozzle 3 are at least 2m below the ice layer, this arrangement can ensure that the nozzle 3 is not blocked by large ice blocks, and can be arranged as close to the water surface as possible to reduce the pressure of the air compressor 1.

[0052] In the above embodiment, the nozzle 3 is a one-way nozzle with a diameter of 80mm-120mm. This design can prevent large ice blocks from blocking the nozzle and ensure that the ejected bubbles 8 can push away the broken ice 9, thereby reducing the drag of the icebreaker.

[0053] In summary, in the distributed icebreaker bubble drag reduction system provided in this embodiment, nozzles 3 are formed in the bilge 10 of the icebreaker through the ventilation pipes 2 of multiple bubble generators. After the icebreaker breaks the ice at the bow, compressed air is delivered to the ventilation pipes 2 by the air compressor 1 and ejected from the nozzles 3 to generate bubbles 8. The bubbles 8 are dispersed from the bilge 10 of the icebreaker to the side, which can push away the broken ice 9 generated after the icebreaker breaks the ice at the bow, reduce the frictional resistance between the broken ice 9 and the icebreaker hull, and thus achieve drag reduction of the icebreaker.

[0054] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A distributed icebreaker bubble drag reduction system, installed on an icebreaker, characterized in that, include: Multiple sets of bubble generators are distributed along the length of the icebreaker from near the bow to the middle of the ship. Each set of bubble generators includes at least two interconnected venting pipes, and each venting pipe forms a nozzle at the bilge of the icebreaker. Multiple air compressors, each air compressor corresponding to each of the aforementioned bubble generators, each of the air compressors being connected to the ventilation pipeline of the corresponding bubble generator, and the air compressors being used to deliver compressed air to the ventilation pipelines; After the icebreaker enters the water, the air compressor delivers compressed air to the ventilation pipeline and sprays it from the nozzle to generate bubbles, thereby pushing away the broken ice generated by the icebreaker's bow. The distance between the bubble generator closest to the bow of the icebreaker and the bow perpendicular of the icebreaker is greater than... ,in ； In the formula, E is the Young's modulus of the ice layer, with a value of 2.0 GPa, and H... ice ρ represents the ice layer thickness in meters (m), V is the Poisson's ratio of the ice layer (0.3), and ρ... w The density of seawater is expressed in kg / m³. 3 g is the acceleration due to gravity, with units of m / s². 2 ; The horizontal distance between adjacent bubble generators is L. pp / 20, where L pp The length between the ship's perpendiculars for an icebreaker; The air compressor corresponding to the bubble generator before the maximum width of the icebreaker has a larger capacity than the air compressor corresponding to the other bubble generators.

2. The distributed icebreaker bubble drag reduction system according to claim 1, characterized in that, The air compressors are positioned near the centerline of the icebreaker, and each air compressor is connected to the ventilation pipeline via a connecting pipe.

3. The distributed icebreaker bubble drag reduction system according to claim 1, characterized in that, Each of the aforementioned ventilation pipes is fitted to the inner side of the icebreaker, and the ventilation pipes of each group of bubble generators are symmetrical about the mid-longitudinal section of the icebreaker.

4. The distributed icebreaker bubble drag reduction system according to claim 1, characterized in that, The ventilation line is equipped with a check valve near the nozzle and a shut-off valve near the air compressor.

5. The distributed icebreaker bubble drag reduction system according to claim 1, characterized in that, The vertical distance between the nozzle and the layer of ice is at least 2m.

6. The distributed icebreaker bubble drag reduction system according to claim 1, characterized in that, The nozzle is a one-way nozzle.

7. The distributed icebreaker bubble drag reduction system according to claim 1, characterized in that, The diameter of the nozzle is 80mm-120mm.

Images