Method for regulating and controlling rotating speed of rotating cylinder of rotating cylinder sail navigation aiding ship

Abstract

The invention belongs to the technical field of ship energy conservation and emission reduction, and particularly relates to a rotating cylinder rotating speed regulation and control method for a rotating cylinder sail navigation aided ship. The regulation and control method comprises the following steps: S1, establishing an aerodynamic performance analysis model of the rotary cylinder; s2, drawing an energy-saving effect rose map based on the aerodynamic performance analysis model, and obtaining an effective net power curve under a preset working condition; s3, on the basis of the comprehensive energy-saving mechanism, the starting time and the optimal rotating speed of the rotary drum sail under the preset working condition are determined through the energy-saving effect rose atlas; and S4, based on the working condition monitored in real time, the rotating speed of the rotary drum sail is adjusted to the optimal rotating speed. The rotating speed of the rotary cylinder sail is automatically adjusted based on the starting time and the optimal rotating speed determined by the comprehensive energy-saving mechanism and the energy-saving effect rose map, it is ensured that the rotary cylinder sail can exert the optimal efficiency under different environment conditions, carbon emission in the ship navigation process is effectively reduced, and the method has the advantages of being high in energy-saving efficiency and high in adaptability.

Description

Technical Field

[0001] The present application belongs to the technical field of ship energy conservation and emission reduction, and specifically relates to a method for controlling the rotor speed of a rotor sail-assisted navigation ship. Background Art

[0002] In recent years, the global warming problem has become increasingly serious due to the surge in carbon emissions, and the attention of all sectors of society to energy conservation and emission reduction has reached an unprecedented level. In response to this challenge, governments have introduced a series of policies and measures to promote energy transformation and environmental protection. In this context, wind energy, as a clean and sustainable natural resource, has regained its brilliance as the main energy source of the future and has been widely used in various fields, including the shipping industry.

[0003] In particular, the rotor sail navigation technology, as an innovative breakthrough in the field of ship energy conservation and emission reduction, is gradually becoming an important means to improve the level of green shipping. This technology cleverly converts wind energy into auxiliary power for ship navigation. When the rotation speed of the rotor reaches the best matching state with the external environmental conditions (such as wind speed, wind direction, etc.), it can significantly enhance the energy conservation and emission reduction effect and contribute to the sustainable development of the shipping industry.

[0004] However, achieving precise matching between the rotor speed and the complex and ever-changing external environmental conditions has become a key problem for the further promotion and application of this technology. In other words, how to intelligently control the rotor speed according to the real-time changing natural environmental parameters to maximize the propulsion effect of the sail and minimize the carbon emissions of the ship has become a technical challenge that needs to be solved urgently. Summary of the invention

[0005] The present application aims to provide a method for controlling the rotor speed, which can achieve accurate matching of the rotor speed of a rotor sail-assisted navigation ship with external environmental conditions, thereby enhancing the energy-saving and emission-reduction effects in the process of utilizing wind energy.

[0006] The embodiments of the present application can be implemented through the following technical solutions:

[0007] A method for controlling the rotor speed of a rotor sail-assisted navigation ship comprises the following steps:

[0008] S1: Establishing an aerodynamic performance analysis model of the rotor;

[0009] S2: Drawing a rose diagram of energy-saving effect based on the aerodynamic performance analysis model, and obtaining an effective net power curve under a preset working condition;

[0010] S3: Based on the comprehensive energy-saving mechanism, the energy-saving effect rose diagram is used to determine the start-up timing and the optimal rotation speed of the rotor sail under the preset working conditions;

[0011] S4: Based on the real-time monitored working conditions, the rotation speed of the rotor sail is adjusted to the optimal rotation speed.

[0012] Furthermore, the step S1 includes the following steps:

[0013] S10: constructing a rotating cylindrical geometric model matching the rotating cylinder based on the rotating cylinder;

[0014] S11: constructing a flow field outside the rotating cylinder, and determining the position of the rotating cylinder in the flow field;

[0015] S12: dividing the flow field into an inner area and an outer area based on the fluid velocity, and meshing the inner area and the outer area by a sliding mesh and a stationary mesh respectively;

[0016] S13: Calculating the drag coefficient and lift coefficient of the rotating cylinder;

[0017] S14: reducing the sizes of the sliding grid and the static grid, and then returning to step S13, until the drag coefficient and the lift coefficient no longer change or the change value is less than a second preset value as the grid size decreases, and constructing a final aerodynamic performance analysis model with the sliding grid and the static grid at this time, and then executing step S15;

[0018] S15: Verify the correctness of the aerodynamic performance analysis model.

[0019] Furthermore, the flow field is rectangular.

[0020] Preferably, the length of the flow field is 26 times the diameter of the rotating cylinder, and the width is 20 times the diameter of the rotating cylinder.

[0021] Preferably, the direction in which the combined speed of the ship speed and the wind speed is formed is perpendicular to the width extension direction of the flow field domain.

[0022] Furthermore, the step S2 comprises the following steps:

[0023] S20: using the aerodynamic performance analysis model to perform numerical simulation analysis of a preset working condition, wherein the preset working condition is determined based on different combinations of ship speed, wind speed, wind direction, and rotation speed;

[0024] S21: extracting the resistance and lift acting on the rotor under a preset working condition based on the result of the numerical simulation analysis;

[0025] S22: Calculate the corresponding effective net power based on the resistance, lift, ship speed and rotation speed under the preset working conditions;

[0026] S23: Draw rose diagrams of energy-saving effects under different ship speeds, different wind speeds, different wind directions, and different effective net powers corresponding to different rotation speeds, and obtain effective net power curves under preset working conditions.

[0027] Furthermore, the comprehensive energy-saving mechanism is specifically as follows:

[0028] The classification intervals are based on the variation of the net effective power with the rotor speed, and

[0029] The starting time and the optimal rotation speed of the rotor sail are determined based on the effective net power and the radial gain value of the effective net power curve in each category interval.

[0030] Furthermore, the principles for dividing different categories are as follows:

[0031] The radial gain values ​​of the effective net power curve within each category interval maintain the same positive and negative characteristics.

[0032] Furthermore, the specific strategy for determining the start timing and optimal rotation speed of the rotor sail based on the effective net power and the radial gain value of the effective net power curve in each category interval is:

[0033] When the effective net power is lower than a first preset value, the rotor sail is not started;

[0034] When the effective net power is higher than the first preset value, and the radial gain values ​​of the effective net power curve in the category interval are all positive, it is determined that the sail can be started and the maximum rotation speed corresponding to the interval is used as the optimal rotation speed;

[0035] When the effective net power is higher than the first preset value, and the radial gain values ​​of the effective net power curve in the category interval are all negative, it is determined that the sail can be started and the minimum rotation speed corresponding to the interval is used as the optimal rotation speed;

[0036] When the effective net power is higher than the first preset value, and the radial gain value of the effective net power curve in the category interval first becomes positive and then becomes negative as the rotor speed increases, it is determined that the sail can be started and the speed corresponding to the positive and negative turning points of the radial gain value is the optimal speed;

[0037] When the effective net power is higher than the first preset value, and the radial gain value of the effective net power curve in the category interval first becomes negative and then positive with the increase of the rotor speed, it is determined that the sail can be started and the speed corresponding to the maximum effective net power in the interval is the optimal speed.

[0038] Furthermore, the optimal rotation speed is not greater than the rated maximum rotation speed of the rotor sail.

[0039] The embodiment of the present application provides a method for controlling the rotor speed of a rotor sail-assisted navigation ship, which has at least the following beneficial effects:

[0040] The present application comprehensively determines the start time and optimal speed of the rotor sail through a comprehensive energy-saving mechanism combined with an energy-saving effect rose map, which has significant advantages compared to the method that simply relies on the size of the effective net power. On the one hand, the comprehensive energy-saving mechanism takes into account the influence of various factors on the energy-saving effect of the rotor sail, and the energy-saving effect rose map intuitively shows the energy-saving effect of the rotor sail under different wind directions, so that the start time and the optimal speed can be determined more accurately; on the one hand, the ship will encounter various complex meteorological and navigation conditions during navigation, and the comprehensive energy-saving mechanism and the energy-saving effect rose map can flexibly adjust the start time and the optimal speed of the rotor sail according to different environmental conditions; on the other hand, by combining the route optimization system, the ship can adjust the heading according to the comprehensive energy-saving mechanism and the energy-saving effect rose map, so that the rotor sail is always in the best working condition. Based on the start time and optimal speed determined by the comprehensive energy-saving mechanism and the energy-saving effect rose map, the present application automatically adjusts the rotation speed of the rotor sail, ensuring that the rotor sail can play the best performance under different environmental conditions, thereby effectively reducing the carbon emissions during the navigation of the ship, and has the advantages of high energy-saving efficiency and strong adaptability.

[0041] The present application determines the start-up timing and the optimal speed of the rotor sail by dividing the category intervals and analyzing within the category intervals. On the one hand, this makes the performance under different working conditions clear, enables accurate analysis within different category intervals, and enables targeted optimization and adjustment through the division of category intervals; on the other hand, it can more accurately control the operating parameters of the rotor sail, helping to ensure that the equipment always operates in the best condition, thereby improving energy efficiency and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a flow chart of a method for controlling the rotor speed of a rotor sail-assisted navigation ship in the present application;

[0043] Figure 2 is a flowchart of step S1 in this application;

[0044] Figure 3 A schematic diagram of the flow field established in the aerodynamic analysis model in this application;

[0045] Figure 4 A nearby grid of the rotor sail in this application;

[0046] Figure 5 is the overall computational grid for the flow field;

[0047] Figure 6 is a flowchart of step S2 in this application;

[0048] Figure 7 This is the rose diagram of energy saving effect when the ship speed is 10kn and the wind speed is 15m / s;

[0049] Figure 8 This is the rose diagram of energy saving effect when the ship speed is 12kn and the wind speed is 15m / s;

[0050] Fig. 9 This is the rose diagram of energy saving effect when the ship speed is 10kn and the wind speed is 18m / s. DETAILED DESCRIPTION

[0051] Hereinafter, the present application will be further described based on preferred embodiments with reference to the accompanying drawings.

[0052] The vocabulary in this specification is used to illustrate the embodiments of the present application, but is not intended to limit the present application. Unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, an indirect connection through an intermediate medium, or a communication between the two components. For those skilled in the art, the specific meanings of the above terms in this application can be specifically understood.

[0053] In addition, in the description of the embodiments of the present application, various components on the drawings are enlarged or reduced in size for ease of understanding, but this practice is not intended to limit the scope of protection of the present application.

[0054] The present application provides a method for controlling the rotor speed of a rotating sail-assisted navigation ship (hereinafter referred to as the control method). Figure 1 A flow chart of the control method is shown, as Figure 1 As shown, the control method comprises the following steps:

[0055] S1: Establish the aerodynamic performance analysis model of the rotor;

[0056] like Figure 2 As shown, step S1 includes the following steps:

[0057] S10: A rotating cylindrical geometric model matching the rotating cylinder is constructed based on the rotating cylinder.

[0058] Specifically, the diameter of the circular cross-section of the rotating cylinder is equal to the diameter of the rotor sail. Figure 2 For example, the diameter of the circular cross section of the rotating cylinder in the present application is equal to the diameter of the rotor sail, 3 m.

[0059] S11: Construct a flow field outside the rotating cylinder and determine the position of the rotating cylinder in the flow field.

[0060] In the aerodynamic performance analysis, we construct a flow field to simulate the air flow environment in which the rotor is located during actual operation. This process focuses on the air flow conditions within the limited flow field range, while the flow conditions beyond the flow field range are not considered. On the one hand, by limiting the analysis scope to the flow field, we can focus more on the air flow area around the rotor and its direct impact, so as to more accurately understand the interaction between the rotor and the surrounding fluid, and how this interaction affects the aerodynamic performance of the rotor; on the other hand, simulating and analyzing the entire air flow environment involves a lot of computing resources and time. By limiting the analysis scope to the flow field, the amount of calculation can be significantly reduced and the analysis information can be improved; on the other hand, under reasonable flow field settings, analyzing the air flow conditions within the range can provide reliable aerodynamic performance prediction results.

[0061] In some specific embodiments of the present application, Figure 3 As shown in the figure, the flow field is rectangular. On the one hand, the rectangular flow field can simplify the complexity of the flow problem, making the flow analysis more intuitive and easier to handle; on the other hand, the rectangular flow field can better adapt to the boundary conditions of the vortex to more accurately simulate the flow of the fluid around the vortex.

[0062] In some preferred embodiments of the present application, Figure 3 As shown in the figure, the direction of the combined speed formed by the ship speed and the wind speed is perpendicular to the width extension direction of the flow field, so as to avoid the need to adjust the combined speed based on the direction of the wind speed and the ship speed. On the one hand, the number of variables is reduced, which not only reduces the complexity of the model, but also simplifies the calculation of the flow field, making the analysis process more intuitive and easy to understand, and also reduces the computing resources and improves the computing efficiency; on the other hand, the direction of the aerodynamic effect (such as lift, drag, etc.) is clearer, which is conducive to accurate analysis, and also reduces the errors caused by changes in wind direction and ship speed, and improves the accuracy of the analysis.

[0063] In some preferred embodiments of the present application, Figure 3 As shown, the length of the rectangular flow field is 26 times the diameter of the rotating cylinder, and the width is 20 times the diameter of the rotating cylinder, so as to enclose the influence area of ​​the rotor into the flow field as much as possible.

[0064] In some specific embodiments of the present application, Figure 3 For example, the distance between the center of the rotating cylinder and the long side and the left short side of the rectangular flow field is 6 times the diameter of the sail.

[0065] S12: The flow field is divided into an inner area and an outer area based on the fluid velocity, and the inner area and the outer area are meshed by sliding mesh and stationary mesh respectively.

[0066] Specifically, Figure 4 and Figure 5As shown in the figure, the grids inside and outside the boundary layer of the flow field are divided, and the rotation of the cylinder is realized by using the sliding grid. The flow field is divided into an inner area and an outer area. The inner area is the fluid around the rotating cylinder, which is covered by the sliding grid and has the shape of a circle overlapping the center of the rotating cylinder; the outer area is a stationary grid of the uniform fluid area, and the sliding grid area and the stationary grid area exchange information through the interface to ensure that the interaction between the rotating cylinder and the surrounding fluid can be accurately simulated.

[0067] In some specific embodiments of the present application, when dividing the grid within the boundary layer of the flow field, the number of nodes along the rotating cylinder is first given as 500, and then the height of the first layer of grid is given as 0.00015, followed by the number of boundary layers as 20 and the growth rate of the thickness values ​​of each layer in the boundary layer as 1.15.

[0068] In some specific embodiments of the present application, when dividing the grid outside the boundary layer of the flow field, in the area where the flow field velocity and pressure gradient are large, the grid base size is smaller, and structured grids are used as much as possible.

[0069] In some specific embodiments of the present application, when dividing the inner area of ​​the flow field, the diameter of the circle where the sliding grid is located is twice the diameter of the rotating cylinder.

[0070] S13: Calculate the drag coefficient and lift coefficient of the rotating cylinder.

[0071] In some specific embodiments of the present application, the solution methods for the drag coefficient and the lift coefficient are set: transient solution, SST k-ω turbulence model, COUPLE algorithm, central difference format, time step 0.0001s, a total of 100,000 time steps, each time step has a maximum of 50 iterations, and the residual standard is 10 -5 Based on the above solution settings, calculate the drag coefficient and lift coefficient of the rotating cylinder and record them.

[0072] S14: Reduce the size of the sliding grid and the stationary grid, and then return to step S13 until the drag coefficient and the lift coefficient no longer change or the change value is less than the second preset value as the grid size decreases, and construct the final aerodynamic performance analysis model with the sliding grid and the stationary grid at this time, and then execute step S15.

[0073] In the process of fluid dynamics analysis, especially when it comes to calculating key parameters such as drag coefficient and lift coefficient, the choice of grid scheme is particularly critical. In order to ensure the accuracy and efficiency of the calculation results, we usually need to optimize the grid scheme through a series of iterative steps. Specifically, we will try different numbers of grids, repeat the calculation process, and carefully compare the drag coefficient and lift coefficient under each grid scheme. As the grid size gradually decreases and the number of grids increases accordingly, we will closely monitor the changes of these two coefficients. When the drag coefficient and lift coefficient no longer change significantly, or their change values ​​are less than the preset second preset value, we can assume that the calculation results have converged, and thus determine the final grid scheme. In this process, we will give priority to those schemes with relatively small numbers of grids but converged results, so as to ensure the calculation accuracy while improving the calculation efficiency as much as possible, laying a solid foundation for subsequent in-depth analysis.

[0074] In some specific embodiments of the present application, the number of grids is increased by about 50%.

[0075] In some specific embodiments of the present application, the second preset value is 2%.

[0076] S15: Verify the correctness of the aerodynamic performance analysis model.

[0077] In some specific embodiments of the present application, a working condition with a Reynolds number of 5000 is selected and compared with the results of the classic literature (Aljure DE, Rodríguez I, Lehmkuhl O, et al. Influence of rotation on the flowover a cylinder at Re=5000[J]. International Journal of Heat and FluidFlow. 2015, 55: 76-90). The result error is within 2%, ensuring the correctness of the numerical analysis model.

[0078] In some specific embodiments of the present application, a rotor aerodynamic performance analysis model is established based on CFD software.

[0079] S2: Draw a rose diagram of energy-saving effect based on the aerodynamic performance analysis model, and obtain the effective net power curve under the preset working conditions.

[0080] like Figure 6 As shown, step S2 includes the following steps:

[0081] S20: Use the aerodynamic performance analysis model to perform numerical simulation analysis of preset working conditions, where the preset working conditions are determined based on different combinations of ship speed, wind speed, wind direction, and rotation speed.

[0082] In some specific embodiments of the present application, according to the actual sailing sea conditions of conventional ships, the calculation parameters such as ship speed, wind speed, wind direction, and rotation speed are determined as follows:

[0083] Physical quantity unit Value range Value interval quantity Ship speed k 10～22 2 7 Wind speed m / s 1～21 3 8 wind direction ° 0～360 15 24 Speed rpm 60～540 60 6

[0084] Based on the above calculation parameters, there are 8064 calculation conditions in total, and numerical simulation analysis is carried out one by one.

[0085] S21: Extract the resistance and lift acting on the rotor under the preset working conditions based on the results of numerical simulation analysis.

[0086] S22: Calculate the corresponding effective net power based on the resistance, lift, ship speed and rotation speed under the preset working conditions.

[0087] In some specific embodiments of the present application, take the ship speed of 12 kn, the wind speed of 18 m / s, the rotation speed of 240 rpm (ω=25.13 rad / s), and the wind direction angle of 90° as an example:

[0088] The net available power for this condition is calculated based on the following steps:

[0089] ① Extract the resistance and lift acting on the rotor sail under this working condition;

[0090] ② Solve the components of drag and lift in the direction of the ship's navigation. The two components are combined to obtain the effective thrust of 4447.74N that propels the ship forward;

[0091] ③Then the thrust power of 31517.64W is obtained through the effective thrust and ship speed;

[0092] ④ According to the size of the rotor sail (D = 3m) and the rotation speed, the friction force suffered by the rotor sail is calculated to be 25.39N;

[0093] ⑤ The power consumed by the rotor sail is calculated to be 956.70W;

[0094] ⑥ The effective net power under this working condition obtained by subtracting the power consumption from the pushing power is 26497.93W.

[0095] In summary, the above effective net power calculation process is as follows:

[0096] P 有效净功率 =T 推力 ×V 船速 -F 摩擦 ×V 转速=4447.74×6.1728-25.39×25.13×1.5=26497.93W S23: Draw rose diagrams of energy-saving effects under different ship speeds, different wind speeds, different wind directions, and different effective net powers corresponding to different rotation speeds, and obtain the effective net power curve under the preset working conditions.

[0097] Furthermore, the drawing process of the energy saving effect rose diagram and the effective net power curve is as follows:

[0098] ① Take 360° as the circumferential coordinate and divide it equally according to the same angle interval. At the same time, take the effective net power as the radial coordinate to clearly define the range and interval of the effective net power. The circumferential coordinate and the radial coordinate together construct the basic coordinate system of the energy-saving effect rose diagram;

[0099] ② For the same rotation speed, the effective net power values ​​corresponding to each wind direction are plotted one by one in the coordinate system, and these points are connected in sequence to form a closed curve, which is the effective net power curve;

[0100] ③ According to the corresponding method, draw the effective net power curve at other speeds.

[0101] In some specific embodiments of the present application, Figure 7-Figure 9 As shown, the interval of the circumferential coordinates is 15°, and the effective net power range is -1×10 4 W~6×10 4 W, the interval is 10000W, Figure 7-Figure 9 Rose diagrams of energy saving effects are shown for ship speed of 10 kn and wind speed of 15 m / s, 12 kn and wind speed of 15 m / s, and ship speed of 12 kn and wind speed of 18 m / s respectively.

[0102] S3: Based on the comprehensive energy-saving mechanism, the energy-saving effect rose diagram is used to determine the start-up timing and optimal speed of the rotor sail under the preset working conditions, that is, to determine the start-up timing of the rotor sail and the real-time optimal speed after starting.

[0103] The present application comprehensively determines the start time and optimal speed of the rotor sail through a comprehensive energy-saving mechanism combined with an energy-saving effect rose map, which has significant advantages compared to the method that simply relies on the size of the effective net power. On the one hand, the comprehensive energy-saving mechanism takes into account the influence of various factors on the energy-saving effect of the rotor sail, and the energy-saving effect rose map intuitively shows the energy-saving effect of the rotor sail under different wind directions, so that the start time and the optimal speed can be determined more accurately; on the one hand, the ship will encounter various complex meteorological and navigation conditions during navigation, and the comprehensive energy-saving mechanism and the energy-saving effect rose map can flexibly adjust the start time and the optimal speed of the rotor sail according to different environmental conditions; on the other hand, by combining the route optimization system, the ship can adjust the heading according to the comprehensive energy-saving mechanism and the energy-saving effect rose map, so that the rotor sail is always in the best working condition. Based on the above analysis, it can be seen that the present application automatically adjusts the rotation speed of the rotor sail based on the start time and optimal speed determined by the comprehensive energy-saving mechanism and the energy-saving effect rose map, ensuring that the rotor sail can play the best performance under different environmental conditions, thereby effectively reducing the carbon emissions during the navigation of the ship, and has the advantages of high energy-saving efficiency and strong adaptability.

[0104] Among them, the comprehensive energy-saving mechanism is specifically as follows: dividing the category intervals based on the change of the effective net power with the rotor speed, and determining the starting time and the optimal speed of the rotor sail based on the effective net power and the radial gain value of the effective net power curve in each category interval, and the radial gain value of the effective net power curve is based on the feature extraction of the adjacent curves of the energy-saving effect rose diagram.

[0105] The present application determines the start-up timing and the optimal speed of the rotor sail by dividing the category intervals and analyzing within the category intervals. On the one hand, this makes the performance under different working conditions clear, enables accurate analysis within different category intervals, and enables targeted optimization and adjustment through the division of category intervals; on the other hand, it can more accurately control the operating parameters of the rotor sail, helping to ensure that the equipment always operates in the best condition, thereby improving energy efficiency and economic benefits.

[0106] Furthermore, the principle of dividing different category intervals is that the radial gain value of the effective net power curve in each category interval should maintain the same positive and negative characteristics to ensure the consistency and predictability of the data within the interval. Figure 7-Figure 9 For example, the intersection of different speed values ​​is used as the boundary of adjacent category intervals, so as to ensure the positive and negative characteristics of the radial gain values ​​of each effective net power curve in the same category interval. That is, the maximum effective net power value in each interval corresponds to the same rotor speed value.

[0107] Furthermore, the specific strategy for determining the start timing and optimal rotation speed of the rotor sail based on the effective net power and the radial gain value of the effective net power curve in each category interval is as follows:

[0108] When the effective net power is lower than the first preset value, the effective net power itself is at a relatively low level. No matter what the radial gain value of the effective net power curve is, the rotor sail should not be started under the conditions of the wind direction range.

[0109] by Figure 7 For example, when the wind direction angle θ is in the range of 0°≤θ<15° and 165°<θ≤180°, the radial gain values ​​of the effective net power curve at different speeds are positive and negative, but the effective net power is at a relatively low level at this time, and it is not suitable to start the rotor sail.

[0110] When the effective net power is higher than the first preset value, and the radial gain values ​​of the effective net power curve in the category interval are all positive, it is determined that the sail can be started and the maximum rotation speed corresponding to the interval is used as the optimal rotation speed;

[0111] When the effective net power is higher than the first preset value, and the radial gain values ​​of the effective net power curve in the category interval are all negative, it is determined that the sail can be started and the minimum rotation speed corresponding to the interval is used as the optimal rotation speed;

[0112] When the effective net power is higher than the first preset value, and the radial gain value of the effective net power curve in the category interval first becomes positive and then becomes negative as the rotor speed increases, it is determined that the sail can be started and the speed corresponding to the positive and negative turning points of the radial gain value is the optimal speed;

[0113] When the effective net power is higher than the first preset value, and the radial gain value of the effective net power curve in the category interval first becomes negative and then positive with the increase of the rotor speed, it is determined that the sail can be started and the speed corresponding to the maximum effective net power in the interval is the optimal speed.

[0114] by Figure 7 For example, when the wind direction angle θ is in the range of 15°≤θ<35°, when the speed increases from 60rpm to 240rpm, the radial gain values ​​of each effective net power curve are all positive, and the effective net power curve at this time is coordinated and consistent. When the speed continues to increase from 240rpm, the radial gain value of the effective net power curve begins to turn negative. Therefore, in this wind direction range, the optimal speed N of the rotor sail can be set to 240rpm.

[0115] When the wind direction angle θ is in the range of 35°≤θ<62°, when the rotation speed increases from 60rpm to 420rpm, the radial gain values ​​of each effective net power curve are all positive, and the effective net power curve at this time is coordinated and consistent. When the rotation speed continues to increase from 420rpm, the radial gain value of the effective net power curve begins to turn negative. Therefore, in this wind direction range, the optimal rotation speed N of the rotor sail can be set to 420rpm.

[0116] When the wind direction angle θ is in the range of 62°≤θ<135°, when the rotation speed increases from 60rpm to 300rpm, the radial gain values ​​of each effective net power curve are all positive, and the effective net power curve at this time is coordinated and consistent. When the rotation speed continues to increase from 300rpm, the radial gain value of the effective net power curve begins to turn negative. Therefore, in this wind direction range, the optimal rotation speed N of the rotor sail can be set to 300rpm.

[0117] When the wind direction angle θ is in the range of 135°≤θ<165°, when the rotation speed increases from 60rpm to 240rpm, the radial gain values ​​of each effective net power curve are all positive, and the effective net power curve at this time is coordinated and consistent. When the rotation speed increases from 240rpm to 300rpm, if the wind direction angle is close to 135°, the gain value is positive, and the effective net power value increases slightly. If the wind direction angle is close to 165°, the effective net power value decreases slightly, that is, in the rotation speed range of 240rpm to 300rpm, the effective net power values ​​are close. When the rotation speed continues to increase from 300rpm, the radial gain value of the effective net power curve begins to turn negative. Therefore, in this wind direction range, the optimal rotation speed N of the rotor sail can be set to 240rpm.

[0118] In addition, the energy-saving effect rose diagram is symmetrical about the wind direction, so the result when the wind direction angle θ is 180°<θ<360° is the same as the above Figure 7 The angles in correspondence are the same.

[0119] Based on the above analysis, Figure 7 In the energy-saving rose diagram, the corresponding relationship between each wind direction angle and the optimal speed is as follows:

[0120]

[0121] Figure 7 The division of the category intervals in is based on the above division principle. Based on this division principle, Figure 8 and Fig. 9 The corresponding relationship between the wind direction angle and the optimal speed is as follows:

[0122] based on Figure 8 In the energy-saving rose diagram, the corresponding relationship between each wind direction angle and the optimal speed is as follows:

[0123]

[0124] based on Fig. 9 In the energy-saving rose diagram, the corresponding relationship between each wind direction angle and the optimal speed is as follows:

[0125]

[0126] In some specific embodiments of the present application, the first preset value is 1000W.

[0127] In some specific embodiments of the present application, the radial gain value of the effective net power curve is also subject to cluster analysis, and decision tree technology is used to make decisions based on the cluster analysis. Clustering is used to ensure the accuracy, stability and consistency of the results, and feature (radial gain value) decisions are made through decision trees to ensure the accuracy of category interval division, thereby ensuring the continuity, accuracy and robustness of the data.

[0128] It should be noted that the optimal speed must not be greater than the rated maximum speed of the rotor sail. For example, the rated maximum speed of the rotor sail in this embodiment is 500 rpm. Figure 7-Figure 9 From the correspondence between each wind direction angle and the optimal speed, it can be seen that the optimal speed does not exceed the rated maximum speed. At this time, the optimal speed determined above can be used as the optimal speed corresponding to each working condition and each wind direction angle.

[0129] In some other specific embodiments of the present application, when the determined optimal rotational speed exceeds the rated maximum rotational speed, the rated maximum rotational speed is used as the optimal rotational speed.

[0130] S4: Based on the real-time monitored working conditions, the rotation speed of the rotor sail is adjusted to an optimal rotation speed.

[0131] Specifically, during the actual navigation of the ship, sensors are used to monitor the ship speed and the wind direction and speed of the surrounding environment in real time.

[0132] In some specific embodiments of the present application, the homogenization is calculated every 10 minutes based on the real-time monitored ship speed, wind direction and wind speed.

[0133] Assume that the mean ship speed is V 船均 =11.5kn, mean wind speed V 风均 =17m / s, wind direction angle θ is 80°, and the following is based on the data to explain the process of determining the optimal rotation speed during actual navigation:

[0134] (1) Figure 7-Figure 9 Compare the ship speed and wind speed corresponding to the energy-saving rose diagram in the figure to find the ship speed V closest to the mean ship speed. 船1 =10kn, V 船2 =12kn and wind speed V 风1 =15m / s, V 风2 =18m / s;

[0135] (2) Based on V Ship 2 = 12 kn and V Wind 2 = 18 m / s, V Ship 1 = 10 kn and V Wind 1 = 15 m / s Figure 7-Figure 9 The corresponding energy saving effect rose diagrams are determined as Figure 7 , Fig. 9 ;

[0136] (3) Search from Figure 7 for the optimal rotational speed N1 corresponding to the wind direction angle θ of 80°. After query, N1 = 300 rpm; search from Fig. 9 for the optimal rotational speed N2 corresponding to the wind direction angle θ of 80°. After query, N2 = 420 rpm;

[0137] (4) Since there are two determined optimal rotational speeds, the final optimal rotational speed needs to be determined through these two optimal rotational speeds. In this application, the interpolation method is used to determine the final optimal rotational speed N of the rotary cylinder sail:

[0138] N = N1 + (N2 - N1) ×

【(V_avg_ship - V_ship1) / (V_ship2 - V_ship1) + (V_avg_wind - V_wind1) / (V_wind2 -

[0139] V_wind1)】 / 2 = 385 rpm.

[0140] (5) Adjust the rotational speed of the rotary cylinder sail to 385 rpm.

[0141] The specific implementation manners of this application have been introduced in detail. For those skilled in the art of this technology, without departing from the principle of this application, several improvements and modifications can still be made to this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A method for controlling the rotor speed of a rotor sail-assisted navigation ship, characterized in that: The following steps are involved: S1: Establishing an aerodynamic performance analysis model of the rotor; S2: Drawing a rose diagram of energy-saving effect based on the aerodynamic performance analysis model, and obtaining an effective net power curve under a preset working condition; S3: Based on the comprehensive energy-saving mechanism, the energy-saving effect rose diagram is used to determine the start-up timing and the optimal rotation speed of the rotor sail under the preset working conditions; S4: Based on the real-time monitored working conditions, the rotation speed of the rotor sail is adjusted to the optimal rotation speed.

2. A method for controlling the rotor speed of a rotor sail-assisted navigation vessel according to claim 1, characterized in that: The step S1 comprises the following steps: S10: constructing a rotating cylindrical geometric model matching the rotating cylinder based on the rotating cylinder; S11: constructing a flow field outside the rotating cylinder, and determining the position of the rotating cylinder in the flow field; S12: dividing the flow field into an inner area and an outer area based on the fluid velocity, and meshing the inner area and the outer area by a sliding mesh and a stationary mesh respectively; S13: Calculating the drag coefficient and lift coefficient of the rotating cylinder; S14: reducing the sizes of the sliding grid and the static grid, and then returning to step S13, until the drag coefficient and the lift coefficient no longer change or the change value is less than a second preset value as the grid size decreases, and constructing a final aerodynamic performance analysis model with the sliding grid and the static grid at this time, and then executing step S15; S15: Verify the correctness of the aerodynamic performance analysis model.

3. The method for controlling the rotor speed of a rotor sail-assisted navigation vessel according to claim 2, characterized in that: The flow field is rectangular.

4. The method for controlling the rotor speed of a rotor sail-assisted navigation vessel according to claim 3, characterized in that: The length of the flow field is 26 times the diameter of the rotating cylinder, and the width is 20 times the diameter of the rotating cylinder.

5. The method for controlling the rotor speed of a rotor sail-assisted navigation vessel according to claim 3, characterized in that: The direction in which the combined speed of the ship speed and the wind speed is formed is perpendicular to the width extension direction of the flow field domain.

6. The method for controlling the rotor speed of a rotor sail-assisted navigation vessel according to claim 1, characterized in that: The step S2 comprises the following steps: S20: using the aerodynamic performance analysis model to perform numerical simulation analysis of a preset working condition, wherein the preset working condition is determined based on different combinations of ship speed, wind speed, wind direction, and rotation speed; S21: extracting the resistance and lift acting on the rotor under a preset working condition based on the result of the numerical simulation analysis; S22: Calculate the corresponding effective net power based on the resistance, lift, ship speed and rotation speed under the preset working conditions; S23: Draw rose diagrams of energy-saving effects under different ship speeds, different wind speeds, different wind directions, and different effective net powers corresponding to different rotation speeds, and obtain effective net power curves under preset working conditions.

7. The method for controlling the rotor speed of a rotor sail-assisted navigation vessel according to claim 1, characterized in that: The comprehensive energy-saving mechanism is specifically: The classification intervals are based on the variation of the net effective power with the rotor speed, and The starting time and the optimal rotation speed of the rotor sail are determined based on the effective net power and the radial gain value of the effective net power curve in each category interval.

8. The method for controlling the rotor speed of a rotor sail-assisted navigation vessel according to claim 7, characterized in that: The principles for dividing different categories are as follows: The radial gain values ​​of the effective net power curve within each category interval maintain the same positive and negative characteristics.

9. The method for controlling the rotor speed of a rotor sail-assisted navigation vessel according to claim 8, characterized in that: The specific strategy for determining the start timing and optimal rotation speed of the rotor sail based on the effective net power and the radial gain value of the effective net power curve in each category interval is: When the effective net power is lower than a first preset value, the rotor sail is not started; When the effective net power is higher than the first preset value, and the radial gain values ​​of the effective net power curve in the category interval are all positive, it is determined that the sail can be started and the maximum rotation speed corresponding to the interval is used as the optimal rotation speed; When the effective net power is higher than the first preset value, and the radial gain values ​​of the effective net power curve in the category interval are all negative, it is determined that the sail can be started and the minimum rotation speed corresponding to the interval is used as the optimal rotation speed; When the effective net power is higher than the first preset value, and the radial gain value of the effective net power curve in the category interval first becomes positive and then becomes negative as the rotor speed increases, it is determined that the sail can be started and the speed corresponding to the positive and negative turning points of the radial gain value is the optimal speed; When the effective net power is higher than the first preset value, and the radial gain value of the effective net power curve in the category interval first becomes negative and then positive with the increase of the rotor speed, it is determined that the sail can be started and the speed corresponding to the maximum effective net power in the interval is the optimal speed.

10. The method for controlling the rotor speed of a rotor sail-assisted navigation vessel according to claim 1, characterized in that: The optimal rotation speed is no greater than the rated maximum rotation speed of the rotor sail.

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