CN116902188A - A method of lowering the sail of an airfoil sail determined by wind speed - Google Patents

Abstract

A method for lowering the sail of wing-shaped wind sail is characterized by that a bow draft sensor and a stern draft sensor are respectively arranged at the bottoms of bow and stern of ship, a ship body coordinate system is built, the relative wind speed at the top of wind sail is monitored in real time, the difference between the manually set wind speed and the relative wind speed is judged, and the sail surface is lowered section by section. Aiming at wing-shaped sail boosting devices with different sections, the attitude of a ship in a marine environment, the horizontal distance between the highest point of a sail and the real-time wind speed are considered, a sail lowering control strategy applicable to different wind speeds is established, the maximum using time length can be provided for the multi-section sail, and the using efficiency of the sail is increased. And through the alarm when the wind speed limit value is not reached, buffering is provided for a shipman, meanwhile, when the wind speed limit value is reached, the sail is directly lowered, safety guarantee is provided for the sail, and an optimal sail lowering control strategy is realized based on the top wind speed of the sail.

Description

A method of lowering the sail of an airfoil sail determined by wind speed

Technical field

The invention belongs to the field of airfoil sail construction and design, and specifically relates to a method for lowering the airfoil sail determined by wind speed.

Background technique

With the promulgation and implementation of new low-carbon emission reduction regulations around the world, the global shipping and shipbuilding industries are developing in a green direction. Marine sails are driven by wind energy, a clean energy source.

This patent uses the aerodynamic characteristics, quantity, ship status, hull motion parameters, etc. of the sail itself as input, and is based on the research results of ship sailing performance with airfoil sails installed. It takes the best energy-saving effect as the control goal and takes into account the safety of ship navigation. , proposed a control method for the sail boosting system of an airfoil sailboat.

Since the airfoil sail system is an original innovation and there is no reference method for control, this control method is proposed for the first time. When the sail is raised, when the relative wind speed exceeds the design wind speed of the sail, the sail structure will be at risk of failure, and the sail needs to be lowered. Therefore, the control method of this patent is proposed. When 0 ≤ design relative wind speed - sail When the top relative wind speed ≤ 2, the control system will alarm. When the alarm time exceeds the design time, the sail will automatically drop one or more knots to determine whether the wind speed meets the requirements, until all sail sections are lowered and recovered to zero position; when the designed relative wind speed Wind speed - When the relative wind speed at the top of the sail is ≤ 0, since the sail has multiple knots, it will automatically drop one or more knots to determine whether the wind speed meets the requirements, until all sail sections are lowered and recovered to the zero position to ensure the safety of the sail system.

This patent uses information such as monitoring wind speed, ship draft, sail position and characteristics as input, based on the design wind speed, with the control goal of ensuring the safety of the sail and ship, taking into account the safety of ship navigation, and proposes an airfoil sail system determined by wind speed. sail lowering control strategy.

Contents of the invention

In order to solve the above problems, the present invention provides a method for lowering the sail of an airfoil determined by wind speed, aiming to achieve the purpose of making the sailboat have the best energy-saving effect under complex and meteorological conditions. The technical solution adopted is: :

A method of lowering the sails of an airfoil sail determined by wind speed. A method of lowering the sails of an airfoil sail determined by the wind speed. A bow draft sensor and a stern draft sensor are respectively provided at the bottom of the bow and stern of the ship.

Establish a hull coordinate system. The origin of the hull coordinate system is the intersection of the ship's symmetrical longitudinal section, stern end and baseline, denoted as O. The X-axis is the longitudinal axis, the Y-axis is the transverse axis, and the Z-axis is the vertical axis.

Real-time monitoring of the relative wind speed Vs’ at the top of the sail,

In the formula, V ₀ is the wind speed at a height of 10 meters above sea level,

TF is the bow draft of the ship,

TA is the stern draft,

LA is the distance between the bow draft sensor and the stern draft sensor,

LS is the distance between the top of the sail and the ship's stern draft sensor,

D is the depth of the ship;

Vs is the artificially set wind speed. When 0≤Vs-Vs’≤2, an alarm will be issued. If the alarm continues for more than 2 minutes, the sail will automatically lower one section of sail surface to further determine whether the wind speed Vs’ meets the requirements.

In the formula, B is the height of one sail section. If the requirements are not met, another section of sail section will be lowered until all sail sections are lowered and recovered.

When Vs-Vs’ ≤ 0, the sail will automatically lower one or more knots to further determine whether the wind speed meets the requirements until all sail sections are lowered and recovered.

When the monitored wind speed Vs’ exceeds the design wind speed Vs, the sail will be lowered and recovered.

According to the above-mentioned airfoil sail lowering method determined by wind speed, furthermore, a bow draft sensor and a stern draft sensor are respectively provided at the bottom of the bow and stern of the ship.

The above-mentioned airfoil sail lowering method determined by wind speed, furthermore, the number of installed sails is N,

When N=1, the sail can directly lower the sail through the action mechanism.

When N=2n+1, n=1,2,..., they are divided into two groups from bow to stern, and the last one is an independent group. First, the group of sails closest to the bow is lowered, and then Lower each set of sails in sequence from bow to stern.

When N=2n, n=1,2,..., they are divided into groups of two sails from the bow to the stern. First, the group of sails closest to the bow is lowered, and then the sails are lowered in sequence from the bow to the stern. Set sail.

In the above-mentioned airfoil sail lowering method determined by wind speed, furthermore, sails are symmetrically arranged on both the port and starboard sides of the ship.

In the above-mentioned method of lowering the sail of an airfoil-shaped sail determined by wind speed, furthermore, the sail has a multi-section mast, and a sail surface is fixed on the mast.

For the above-mentioned airfoil sail lowering method determined by wind speed, further, the X-axis is positive forward, the Y-axis is positive to the left, and the Z-axis is positive upward.

The above-mentioned airfoil sail lowering method determined by wind speed, further, when the average atmospheric temperature Tt for 30 minutes is measured to be lower than 4°C weather conditions, the sail is lowered and retracted.

Assume that the time at each moment is t, and the time nodes 1800 seconds before moment t are t-10s, t-20s,..., t-1800s. The atmospheric temperature dt- _10i corresponding to these time nodes is averaged, that is for Tt

The beneficial effects of the present invention are as follows:

1. The sail lowering control strategy determined by the meteorological environment takes the design wind speed as the limiting condition, accurately gives the relationship between the sail top wind speed and the design wind speed, and determines the limiting wind speed at which the sail needs to be lowered.

2. It can be judged whether the sail still meets the wind speed limit after being lowered by n knots. It provides a solution to reduce the number of sail surfaces, increases the usable time of the sail, and increases economy.

Description of the drawings

Figure 1 is a schematic diagram of the hull coordinate system;

Figure 2 is a schematic diagram of the sail being retracted, that is, in the zero position;

Figure 3 is a schematic diagram of the conversion between the wind speed at the top of the sail and the design wind speed;

Among them: 1-stern draft sensor, 2-bow draft sensor, 3-sail, 4-main deck, 5-water plane, 7-top of sail, 8-bottom.

Detailed ways

The present invention will be further described with reference to the accompanying drawings.

A method of lowering the sail of an airfoil sail determined by wind speed. For airfoil sail boosters with different numbers of knots, the attitude of the ship in the marine environment, the horizontal distance from the highest point of the sail and the real-time wind speed are taken into account, and a method is established that is suitable for different The wind speed sail lowering control strategy can provide the maximum usage time for multi-knot sails and increase the usage efficiency of the sails.

By alarming when the wind speed limit is not reached, a buffer is provided for the crew, and at the same time, the sail is lowered directly when the limit is reached, providing safety guarantee for the sail.

As shown in Figure 1, establish a hull coordinate system. The origin of the hull coordinate system is the intersection of the ship's symmetrical longitudinal section, stern end and baseline, denoted as O. The X-axis is the longitudinal axis, forward is positive, and the Y-axis is transverse. axis, the left direction is positive, the Z-axis is the vertical axis, and the upward direction is positive.

When the measured average atmospheric temperature Tt for 30 minutes is lower than 4℃, the sail will be automatically lowered to the zero position (placement state). The calculation method of Tt is, assuming the time at each moment is t. Since the time step of the sail control system to record the real-time atmospheric temperature is 10 seconds, the atmospheric temperature data 30 minutes (1800 seconds) before time t is t-10s, t The dt-10i corresponding to the time points of -20s,...,t-1800s, average the atmospheric temperatures at these moments, which is Tt,

When the sail is raised, when the monitored wind speed exceeds the design wind speed Vs of the sail, there is a risk of structural failure of the sail, and the sail needs to be lowered. The control method is that when 0 ≤ design relative wind speed - sail top relative wind speed ≤ 2, the control system will alarm. When the alarm time exceeds the design time, the sail will automatically drop one or more knots to determine whether the wind speed meets the requirements until all sail sections are reached. All surfaces are lowered and recovered to the zero position (as shown in Figure 2); when the design relative wind speed-sail top relative wind speed ≤ 0, since the sail has multiple knots, it will automatically drop one or more knots to determine whether the wind speed meets the requirements, until all All sail sections are lowered and recovered to the zero position. Since the relative wind speed cannot be obtained directly at the top of the sail, it needs to be obtained by converting the ship's draft and relevant parameters of the sail itself, as described in detail below.

Set up an alarm device. The design wind speed of the sail top of the airfoil sail is Vs. The wind speed V0 at a height of 10 meters above the sea level can be obtained on the ship. V0 can be transformed to obtain the monitored wind speed Vs' of the sail top. When 0≤Vs-Vs'≤ An alarm will be issued at 2 o'clock, and if the alarm continues for more than 2 minutes, the sail will automatically lower one or more knots to further determine whether the wind speed meets the requirements, until all sail sections are lowered and recovered to zero position; when Vs-Vs' ≤ 0 , the sail automatically lowers one or more knots to further determine whether the wind speed meets the requirements, until all sail sections are lowered and returned to the zero position (as shown in Figure 2).

After the sail is retracted, it should be placed in the "zero position". When the port sail is retracted, the sail rotation angle is -90°, and when the starboard sail is retracted, the sail rotation angle is +90°.

The number of installed sails is N,

When N=1, the sail can directly lower the sail through the action mechanism.

When N=2n+1, n=1,2,..., they are divided into two groups from bow to stern, and the last one is an independent group. First, the group of sails closest to the bow is lowered, and then Lower each set of sails in sequence from bow to stern.

When N=2n, n=1,2,..., they are divided into groups of two sails from the bow to the stern. First, the group of sails closest to the bow is lowered, and then the sails are lowered in sequence from the bow to the stern. Set sail.

In order to obtain the monitored wind speed Vs' at the top of the sail, we first need to obtain the wind speed V ₀ at a height of 10 meters above sea level,

Where H is the distance between the top of the sail and the sea level. Then as long as H is obtained in the above formula, Vs’ can be obtained. The method is as follows:

As shown in Figure 3, the bow draft of the ship measured by the bow draft sensor 2 and the stern draft sensor 1 is TF, the stern draft is TA, and the distance between the bow draft sensor 2 and the stern draft sensor 1 is LA. The distance between sail 3 and the ship's stern draft sensor 1 is LS, and the ship's depth is D. Then the draft TS at the position of the sail is:

Then the distance between the main deck 4 and the water plane 5 where the sail is located is D-TS. get at the same time

By taking the distance between the top of the sail 7 and the bottom of the ship 8, subtracting the draft TS at the location of the sail, and then projecting it in the direction vertical to the sea level, the vertical distance H between the top of the sail 7 and the water plane 5 can be obtained. The distance between the top of the sail 7 and the bottom 8 of the ship can be obtained by the distance HS between the top of the sail 7 and the main deck 4, plus the molded depth D of the ship. The above calculation process is as follows:

H＝(HS+D-TS)cosβ

By bringing the vertical distance H between the top of the sail 7 and the water plane 5 into the following formula, the monitored wind speed Vs’ at the top of the sail can be obtained.

When the wind speed does not meet the requirements, one or more sail sections need to be lowered. The sail has n sail surfaces 6, and the height of each sail surface is B. Then H at this time is calculated as follows:

H＝(HS+D-TS-NB)cosβ，n-1＞N≥0

Put H back into the following formula to determine whether the wind speed requirements are met.

An example is as follows. When the sails are all raised, H=(HS+D-TS)cosβ, and the measured wind speed V0 at a height of 10 meters above sea level, then

If it is judged that the sail needs to be lowered at this time, the top sail surface can be lowered and the other sail surfaces remain unchanged. Then calculate Vs’ after lowering one section of sail surface. At this time

H=(HS+D-TS-B)cosβ, then

Continue to compare Vs’ with Vs at this time and make a judgment, and so on.

When the real-time monitored reference wind direction remains at [0°~20°] and (340°~360°) for 10 consecutive minutes, the crew is prompted to set the sail to the zero position; the real-time monitored reference wind direction remains at [20°~340 for 10 consecutive minutes °] range, and Vs'+4 is less than Vs at the same time, prompting the crew to raise the sail.

The sail lowering control strategy determined by the meteorological environment of the present invention takes the design wind speed as the limiting condition, accurately provides the relationship between the sail top wind speed and the design wind speed, and determines the limiting wind speed at which the sail needs to be lowered. It can be judged whether the sail still meets the wind speed limit after being lowered by n knots. It provides a solution to reduce the number of sail surfaces, increases the usable time of the sail, and increases economy.

Claims (7)

1. An airfoil sail lowering method determined by wind speed, which is characterized in that: a bow draft sensor and a stern draft sensor are respectively arranged at the bottoms of a bow part and a stern part of a ship, a ship body coordinate system is established, the origin of the ship body coordinate system is the intersection of a symmetrical longitudinal section of the ship, the tail end and a base line, the intersection is marked as O, an X axis is a longitudinal axis, a Y axis is a transverse axis, and a Z axis is a vertical axis;

the relative wind speed Vs' at the top of the sail is monitored in real time,

wherein V is ₀ For wind speeds at 10 meters height from sea level,

TF is the draft of the bow of the ship,

TA is the draft of the stern,

LA is the distance between the bow draft sensor and the stern draft sensor,

LS is the distance of the top of the sail from the stern draft sensor of the ship,

d is the depth of the ship;

vs is a manually set wind speed, when the wind speed is less than or equal to 0 and less than or equal to Vs-Vs 'and less than or equal to 2, the warning time is longer than 2 minutes, the sail automatically descends a section of sail surface, whether the wind speed Vs' meets the requirement is further judged,

wherein B is the height of a sail surface,

if the requirements are not met, one section of sail surface is lowered until all sections of sail surface are lowered and recovered;

when Vs-Vs' is less than or equal to 0, automatically descending one or more sections of the sail to further judge whether the wind speed meets the requirement or not until all sections of sail surfaces are completely descended and recovered;

when the monitored wind speed Vs' exceeds the design wind speed Vs, the sail is lowered and recovered.

2. A wind speed dependent airfoil sail lowering method according to claim 1, wherein: the number of the airfoil shaped wind sail boosting devices is N,

when n=1, the sail can directly complete the sail lowering action through the action mechanism;

when n=2n+1, n=1, 2, …, dividing each 2 from the bow to the stern into one group, and finally, 1 independently forming one group, firstly lowering a group of sails closest to the bow, and then sequentially lowering each group of sails according to the sequence from the bow to the stern;

when n=2n, n=1, 2, …, the sails are grouped every 2 from bow to stern, the sails closest to the bow are lowered first, and then the sails are lowered in turn in the order from bow to stern.

3. A wind speed dependent airfoil sail lowering method according to claim 1, wherein: the port board and the starboard board of the ship are symmetrically provided with sails.

4. A wind speed dependent airfoil sail lowering method according to claim 1, wherein: the sail is provided with a plurality of sections of masts, and a sail surface is fixed on the masts.

5. A wind speed dependent airfoil sail lowering method according to claim 1, wherein: the X-axis is positive forward, the Y-axis is positive to the left, and the Z-axis is positive.

6. A wind speed dependent airfoil sail lowering method according to claim 1, wherein: the rotation angle of the wind sail is-90 degrees when the port sail is in a retracted state, and the rotation angle of the wind sail is +90 degrees when the starboard sail is in a retracted state.

7. A wind speed dependent airfoil sail lowering method according to claim 1, wherein: when the measured 30-minute atmospheric average temperature Tt is lower than the weather condition of 4 ℃, the sail is retracted;

setting the time of each time as t, the time nodes of 1800 seconds before the t time as t-10s, t-20s, … … and t-1800s, and setting the atmospheric temperature dt- _10i Taking the average value to be Tt。