Rotary drum sail capable of being intelligently regulated and controlled and design method thereof

Abstract

The invention relates to a rotary drum sail and a design method thereof, in particular to an intelligently-adjustable rotary drum sail and a design method thereof. The invention aims to solve the problems that the height and the rotating speed of the conventional rotary cylinder sail for the ship are generally fixed and cannot be changed, and the change of downflow conditions under different sea conditions is not considered, so that the rotary cylinder sail cannot sufficiently utilize wind energy. The rotating cylinder sail capable of being intelligently regulated and controlled comprises a base, the middle of the lower surface of the base is fixedly connected with the output end of a rotating shaft, the input end of the rotating shaft is connected with a rotating driving motor, and the upper surface of the base is sequentially connected with a plurality of lifting rotating cylinder units from top to bottom. The invention belongs to the technical field of rotary cylinder sail design.

Description

Technical Field

[0001] The invention relates to a rotor sail and a design method thereof, belonging to the technical field of rotor sail design. Background Art

[0002] The height and speed of existing rotor sails used on ships are generally fixed and cannot be changed. They do not take into account the changes in downflow conditions under different sea conditions. Therefore, such rotor sails do not fully utilize wind energy.

[0003] The invention patent with publication number CNCN115027652A and application date of July 15, 2022 discloses a sail propulsion device based on a rotor sail and a ship, which is used for ships. The sail propulsion device based on the rotor sail includes: a support assembly arranged on the ship; a lifting and rotating assembly arranged on the top of the support assembly; a rotor sail arranged on the lifting and rotating assembly, and the rotor sail is driven by the lifting and rotating assembly to achieve lifting and rotation. The sail propulsion device based on the rotor sail drives the rotor sail to be lifted and rotated by the lifting and rotation of the lifting rod, thereby achieving wind-assisted navigation when the wind direction and wind force are suitable and the conditions for wind-assisted navigation are met, saving energy consumption, low carbon and environmental protection; when the wind direction and wind force are not suitable and the conditions for wind-assisted navigation are not met, the rotor sail can automatically retract into the interior of the hull, saving the use space of the hull and deck, and saving labor costs.

[0004] The invention patent with publication number CN111532409A and application date of May 15, 2020 discloses a lifting type rotor sail device, including a support assembly, a scissor-type lifting assembly and a sail assembly, wherein the sail assembly and the scissor-type lifting assembly are both mounted on the support assembly, the scissor-type lifting assembly is located inside the sail assembly, the sail assembly includes an outer cylinder, a first inner cylinder, a second inner cylinder, a deflection assembly and two sets of guide assemblies, the scissor-type lifting assembly includes a lifting plate, a load-bearing plate, an electric cylinder, two sets of first support rods and two sets of second support rods, the two sets of guide assemblies include two sets of sliders and two sets of slide grooves, a support assembly, and the support assembly includes a fixed plate, a support plate, a support shaft and a power assembly. The present invention can solve the problem that the existing rotor sail device has a limited wind energy contact surface and a low wind energy utilization rate when utilizing wind energy, and the rotor sail device cannot be raised or lowered, which easily affects the operation of the boom when loading and unloading cargo on the ship.

[0005] However, the rotor sails described in the above two documents can only achieve single-section lifting and lowering, and cannot achieve multi-section lifting and lowering, and no specific design method is disclosed. Summary of the Invention

[0006] The present invention aims to solve the problem that the height and speed of existing rotor sails used on ships are generally fixed and cannot be changed, and do not take into account the changes in downflow conditions under different sea conditions. Therefore, such rotor sails do not fully utilize wind energy. The present invention further proposes an intelligently controllable rotor sail and a design method thereof.

[0007] The technical solution adopted by the present invention to solve the above problems is: the intelligently controllable rotor sail described in the present invention includes a base, the middle part of the lower surface of the base is fixedly connected to the output end of the rotating shaft, the input end of the rotating shaft is connected to a rotating drive motor, and the upper surface of the base is connected to multiple lifting rotor units in sequence from top to bottom.

[0008] Furthermore, each lifting drum unit consists of a large diameter drum, a small diameter drum and an electric lifting hydraulic cylinder; the electric lifting hydraulic cylinder is vertically arranged in the large diameter drum, and the piston rod of the electric lifting hydraulic cylinder is fixedly connected to the bottom surface of the small diameter drum.

[0009] The method for designing an intelligently controllable rotor sail of the present invention comprises the following steps:

[0010] Step 1: Design the rotor sail in two dimensions;

[0011] Step 2: Based on the optimal two-dimensional parameters, a three-dimensional sail model is constructed;

[0012] Step 3: Three-dimensional design; simulate and calculate the three-dimensional sail lift value under different incoming flow speeds, analyze the relationship between the sail lift and the incoming flow speed, and verify the correctness of the structure based on the pressure and velocity cloud diagrams.

[0013] Furthermore, in step 101, according to Bernoulli's principle, the dynamic pressure of the fluid in the area where the flow velocity increases decreases significantly, while the static pressure in the area where the flow velocity decreases increases relatively. This forms a pressure gradient on the cross section of the object, thereby generating a lateral force perpendicular to the direction of motion. This lateral force can be quantitatively described in a two-dimensional flow field using the Joukowski lift theorem as:

[0014] L=2πωr 2 ρ A V a ,

[0015] Where L is the lift generated by the Magnus effect; ω is the angular velocity; r is the radius of the drum; ρ A Indicates air density; V a Indicates wind speed;

[0016] Step 102, the sail speed is preset in a range of 45 to 120 rpm;

[0017] Step 103: determine the incoming flow velocity and analyze the variation of the sail lift with the rotation speed and the sail diameter;

[0018] Step 104: Determine the sail diameter and rotation speed under the condition of maximum lift; based on the diameter and rotation speed under maximum lift, change the incoming flow velocity and analyze the lift variation law;

[0019] Step 105: adopt an equal-interval sampling method to ensure that the analysis structure reflects the relationship between the actual lift and the diameter and the incoming flow velocity.

[0020] Furthermore, in step 105, the diameter variation range is 3-5m, the sampling point interval is 0.5m, and there are 5 sampling points at the same speed; the speed variation range is 45-120rmp, the sampling point interval is 15rmp, and there are 6 sampling points at the same diameter.

[0021] The beneficial effects of the present invention are:

[0022] 1. The present invention takes thrust as the optimization goal and ultimately obtains a rotor sail with the maximum thrust. When installed on a bulk carrier, it can provide a large amount of thrust for the ship, reduce fuel consumption during navigation, and have significant economic benefits.

[0023] 2. This invention improves the existing fixed rotor sail, enabling it to intelligently adjust its speed and height according to different sea conditions, further improving energy conversion efficiency and reducing fuel consumption;

[0024] 3. This invention uses the rotor sail diameter, rotation speed, and incoming flow velocity as input variables and the lift provided by the sail as output variable to explore the optimal energy-saving efficiency of the rotor sail;

[0025] 4. Through fluid simulation and analysis, the relationship between the rotor sail diameter, rotation speed, incoming flow velocity and sail lift is established; based on the incoming flow conditions, the rotor speed and height are adjusted in combination with an intelligent control system to improve efficiency;

[0026] 5. The rotor sail of the present invention occupies little space on the hull and deck, has a larger windward area, and can better utilize wind energy; the present invention realizes wind-assisted navigation when the wind direction and wind force are suitable and meet the conditions for wind-assisted navigation, saving energy consumption, and being low-carbon and environmentally friendly; when the wind direction and wind force change, the rotor sail can automatically extend and retract the height of the rotor to improve efficiency, reduce energy consumption, save the use space of the hull and deck, and save labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the structure of an intelligently adjustable rotor sail;

[0028] Figure 2 It is a schematic diagram of the two-dimensional computational domain grid division;

[0029] Figure 3 It is a three-dimensional rotor sail performance distribution map;

[0030] Figure 3 (a) is the sail speed distribution diagram;

[0031] Figure 3 (b) is the sail pressure distribution diagram;

[0032] Figure 4 It is a diagram of the intelligent height control of the rotor sail. DETAILED DESCRIPTION

[0033] Specific implementation method 1: Figure 1 As shown, the intelligently controllable rotor sail includes a base 1, the middle of the lower surface of the base 1 is fixedly connected to the output end of the rotating shaft 2, the input end of the rotating shaft 2 is connected to a rotating drive motor, and the upper surface of the base 1 is connected to multiple lifting rotor units in sequence from top to bottom.

[0034] Each lifting drum unit consists of a large-diameter drum 3, a small-diameter drum 4, and an electric lifting hydraulic cylinder 5. The electric lifting hydraulic cylinder 5 is vertically arranged inside the large-diameter drum 3, and its piston rod is fixedly connected to the bottom surface of the small-diameter drum 4. The electric lifting hydraulic cylinder 5 drives the small-diameter drum 4 to be retracted into the large-diameter drum 3 or extended out of the large-diameter drum 3 along a straight line through its piston rod.

[0035] Specific implementation method 2: Figures 2 to 4 As shown, the design method of the intelligently controllable rotor sail comprises the following steps: Step 1, performing a two-dimensional design of the rotor sail; specifically comprising:

[0036] Step 101: According to Bernoulli's principle, the dynamic pressure of the fluid in the area where the flow velocity increases decreases significantly, while the static pressure in the area where the flow velocity decreases increases relatively. This forms a pressure gradient on the cross section of the object, thereby generating a lateral force perpendicular to the direction of motion. This lateral force can be quantitatively described in a two-dimensional flow field using the Joukowski lift theorem as:

[0037] L=2πωr 2 ρ A V a ,

[0038] Where L is the lift generated by the Magnus effect; ω is the angular velocity; r is the radius of the drum; ρ A Indicates air density; V a Indicates wind speed;

[0039] Step 102, the sail speed is preset in a range of 45 to 120 rpm;

[0040] Step 103: determine the incoming flow velocity and analyze the variation of the sail lift with the rotation speed and the sail diameter;

[0041] Step 104: Determine the sail diameter and rotation speed under the condition of maximum lift; based on the diameter and rotation speed under maximum lift, change the incoming flow velocity and analyze the lift variation law;

[0042] Step 105: adopt an equal-interval sampling method to ensure that the analysis structure reflects the relationship between the actual lift and the diameter and the incoming flow velocity; the diameter range is 3-5m, the sampling point interval is 0.5m, and there are 5 sampling points under the same rotation speed; the rotation speed range is 45-120rpm, the sampling point interval is 15rpm, and there are 6 sampling points under the same diameter;

[0043] Step 2: Based on the optimal two-dimensional parameters, a three-dimensional sail model is constructed;

[0044] Step 3: Three-dimensional design; simulate and calculate the three-dimensional sail lift value under different incoming flow speeds, analyze the relationship between the sail lift and the incoming flow speed, and verify the correctness of the structure based on the pressure and velocity cloud diagrams.

[0045] The theoretical framework of step 101 provides an important tool for the calculation of the aerodynamic force of the rotating body, where X(s, t, u) is the global coordinate of any geometric point in the control body, P i,j,k are the vertex coordinates of the control point, s, t, u are the local coordinates of the controlled geometric point, and R is the basis function type.

[0046] A small sail diameter will result in insufficient lift provided by the sail, resulting in low energy savings. A sail diameter that is too large will increase the sail's power consumption, resulting in a decrease in the sail's energy efficiency. Table 1 shows the diameters of common rotor sails, with the smallest diameter being 3m and the largest being 5m. Therefore, the diameter optimization range in this solution is 3 to 5m. Increasing the sail speed ω can increase the sail thrust F. l Bring greater energy-saving benefits to ships; but when the sail speed ω increases, the sail drive motor power consumption P motor Increases, when the sail speed ω increases, the energy consumption benefit is lower than the increased power consumption ΔP of the motor motor The sail's energy efficiency decreases when the speed is too high. Therefore, the sail's speed is preset to range from 45 to 120 rpm.

[0047] Table 1 Diameter of rotor sails used in ships

[0048]

[0049] It is too difficult to analyze the relationship between the changes of three input variables and one output variable at the same time. In actual design, only the sail diameter and rotation speed are controllable input variables. Therefore, the plan first determines the incoming flow velocity to analyze the change pattern of the sail lift with the rotation speed and sail diameter.

[0050] Table 2 Numerical methods and boundary condition design

[0051]

[0052] The lift-incoming velocity relationship was determined based on the diameter and rotational speed at maximum lift. Samples were taken at equal intervals under common wind speeds (forces 4 to 8) at five sampling points: 7 m / s, 10 m / s, 13 m / s, 17 m / s, and 20 m / s. Calculations revealed that, for a given sail speed, increasing sail diameter increases lift, and thus the lift and sail diameter are positively correlated. For a given sail diameter, increasing sail speed increases lift, and thus the lift and sail speed are positively correlated. After determining the effects of speed and diameter, the influence of incoming velocity was analyzed. The variation of sail lift with incoming velocity was analyzed for a fixed diameter of 5 m and a rotational speed of 120 rpm. In summary, the optimal performance for a two-dimensional sail is achieved when the sail diameter is 5 m and the sail speed is 120 rpm, with a lift of 55,564.09 N.

[0053] The sail flow velocity sampling in step 3 is the same as that in the two-dimensional case. Table 3 shows the calculated three-dimensional sail lift under different flow velocities. Figure 2 This is the sail speed and pressure distribution diagram.

[0054] Table 3 Three-dimensional sail lift at different incoming flow velocities

[0055]

[0056] like Figure 3 In the sail speed distribution diagram shown in (a), there is an obvious difference in the working medium flow rate between the incoming and outgoing sides of the sail. According to the Magnus effect, this flow rate difference leads to a large pressure difference between the incoming and outgoing sides of the sail.

[0057] like Figure 3 The sail pressure distribution diagram shown in (b) directly shows that there is a large pressure difference between the incoming flow surface and the outgoing flow surface of the sail. This pressure difference forms thrust, effectively providing thrust for the ship.

[0058] After analysis, it was found that the lift of the three-dimensional rotor sail increases with the increase of the incoming flow speed. At the same time, according to formula (1), it was calculated that the lift of the rotor sail is also positively correlated with the sail height.

[0059] Intelligent control of rotor sail speed and height

[0060] Through the performance analysis of three-dimensional rotor sails, it is found that the lift of the sail is positively correlated with the speed and height, but higher speed and height require higher motor power. The energy conversion efficiency varies under different sea conditions. Therefore, it is necessary to dynamically adjust the speed and height according to the real-time wind speed and heading. Wind speed sensors, wind direction sensors, height position sensors and speed sensors are deployed in the rotor sail system to collect environmental wind conditions and equipment operating status data in real time, providing input parameters for the intelligent control system. The sensor data is transmitted to the control system through the field bus, and is quickly processed in combination with the PLC and industrial computer to provide support for subsequent decision-making, such as Figure 4 Shown is the effect of the rotor sail automatically adjusting its height.

[0061] A fuzzy control algorithm dynamically adjusts the motor speed based on real-time wind speed and ship heading. This algorithm simulates human reasoning to achieve precise control of complex nonlinear systems, ensuring the rotor sail maintains optimal speed under varying operating conditions. Based on a mathematical model of sail-to-engine matching and combined with collected data on wind speed, direction, and the ship's main engine speed, an intelligent algorithm calculates the optimal height of the rotor sail. Based on this calculation, the system automatically adjusts the lifting mechanism to achieve dynamic optimization of height and maximize wind energy utilization efficiency.

[0062] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement of the above embodiments made according to the technical essence of the present invention, within the spirit and principles of the present invention, without departing from the content of the technical solution of the present invention, shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. Intelligently adjustable rotor sail, characterized by: The base (1) comprises a base, wherein the middle portion of the lower surface of the base (1) is fixedly connected to the output end of a rotating shaft (2), the input end of the rotating shaft (2) is connected to a rotating drive motor, and the upper surface of the base (1) is sequentially connected to a plurality of lifting drum units from top to bottom.

2. The intelligently controllable rotor sail according to claim 1, characterized in that: Each lifting drum unit comprises a large-diameter drum (3), a small-diameter drum (4) and an electric lifting hydraulic cylinder (5); the electric lifting hydraulic cylinder (5) is vertically arranged in the large-diameter drum (3), and the piston rod of the electric lifting hydraulic cylinder (5) is fixedly connected to the bottom surface of the small-diameter drum (4).

3. A design method for the intelligently controllable rotor sail according to claim 1, characterized in that: The specific steps include: Step 1: Design the rotor sail in two dimensions; Step 2: Based on the optimal two-dimensional parameters, a three-dimensional sail model is constructed; Step 3: Three-dimensional design; simulate and calculate the three-dimensional sail lift value under different incoming flow speeds, analyze the relationship between the sail lift and the incoming flow speed, and verify the correctness of the structure based on the pressure and velocity cloud diagrams.

4. The method for designing an intelligently controllable rotor sail according to claim 3, characterized in that: Step 1 specifically includes: Step 101: According to Bernoulli's principle, the dynamic pressure of the fluid in the area where the flow velocity increases decreases significantly, while the static pressure in the area where the flow velocity decreases increases relatively. This forms a pressure gradient on the cross section of the object, thereby generating a lateral force perpendicular to the direction of motion. This lateral force can be quantitatively described in a two-dimensional flow field using the Joukowski lift theorem as: L=2πr 2 r A V a , Where L is the lift generated by the Magnus effect; ω is the angular velocity; r is the radius of the drum; ρ A Indicates air density; V a Indicates wind speed; Step 102, the sail speed is preset in a range of 45 to 120 rpm; Step 103: determine the incoming flow velocity and analyze the variation of the sail lift with the rotation speed and the sail diameter; Step 104: Determine the sail diameter and rotation speed under the condition of maximum lift; based on the diameter and rotation speed under maximum lift, change the incoming flow velocity and analyze the lift variation law; Step 105: adopt an equal-interval sampling method to ensure that the analysis structure reflects the relationship between the actual lift and the diameter and the incoming flow velocity.

5. The method for designing an intelligently controllable rotor sail according to claim 4, characterized in that: In step 105 , the diameter variation range is 3 to 5 m, the sampling point interval is 0.5 m, and there are 5 sampling points at the same rotation speed; the rotation speed variation range is 45 to 120 rpm, the sampling point interval is 15 rpm, and there are 6 sampling points at the same diameter.

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