Method for obtaining sail fuel consumption saving based on measurement data

Abstract

A method for obtaining fuel consumption saving of a sail based on measured data includes the steps that in order to forecast fuel consumption saving of the sail, recorded data of relative wind directions and relative wind speeds are screened out from a plurality of data recorded by a control system, and boosting force of the sail to a ship under different wind directions and wind speeds is calculated in combination with boosting characteristics of the sail. The product of the boosting force and the navigational speed is the boosting power which can be provided by the sail; secondly, screening out records of the power of the host, and calculating daily fuel consumption corresponding to the power actually sent by the host according to a fuel consumption power curve of the host; summing the power of the main engine and the propulsion power of the sail, and calculating corresponding daily fuel consumption when the actual power sent by the ship is provided according to the fuel consumption power curve of the main engine; and finally, calculating the difference between the two calculated daily fuel consumption to obtain the daily fuel consumption saved by the sail for evaluating the energy-saving effect of the sail and the return on investment cycle.

Description

Technical Field

[0001] The invention belongs to the field of design and construction of ships with sails, and in particular relates to a method for obtaining fuel consumption savings of sails based on measurement data. Background Art

[0002] With the promulgation and implementation of new global regulations for low-carbon emissions reduction, the global shipping and shipbuilding industries are moving towards greener development. Marine sail systems, powered by clean wind energy, are revolutionizing the industry internationally. DSIC pioneered the world's first research on wing-shaped wind-powered propulsion for ocean-going cargo vessels, achieving a series of key technological breakthroughs, particularly in calculating the fuel savings of sails using sea trials and operational data.

[0003] The sail control system records a number of data related to the sails and the vessel, including engine power, relative wind direction and speed, vessel speed, and heading. Since sails inherently propel the vessel, naturally saving fuel, it is necessary to inform shipowners and classification societies of the fuel savings achieved by the addition of sails. This information is used to calculate and evaluate the savings.

[0004] This patent aims to predict the fuel consumption saved by sails. According to the power-fuel consumption relationship provided by the main engine manufacturer, the fuel consumption under the current main engine power, that is, the fuel consumption when the main engine power propels the ship, and the fuel consumption corresponding to the ship's propulsion power including the sails are calculated. Among them, the calculation of the propulsion power of the sails requires information such as the propulsion coefficient, air density, relative wind direction, relative wind speed and ship speed at various angles, thereby proposing a method for calculating the fuel consumption saved by sails based on measurement data. Summary of the Invention

[0005] To solve the above problems, the present invention provides a method for obtaining sail fuel consumption savings based on measurement data, the technical solution adopted is:

[0006] A method for obtaining fuel consumption saving of a sail based on measurement data, characterized in that the propulsion power Psi of the sail propulsion system at a certain moment is converted through the propulsion power Ps of the sail propulsion system and the propulsion force Fs of the sail;

[0007] P s =F s ·C (1)

[0008]

[0009] Where C is the ship speed, ρa is the air density, V is the ship relative wind speed, A is the area of ​​the sail propulsion system, αθ is the thrust coefficient under a certain relative wind direction angle, Vii:ii:ii is the ship relative wind speed at a certain moment, αii:ii:ii is the thrust coefficient under a certain relative wind direction angle at a certain moment obtained by interpolation, and Cii:ii:ii is the ship speed at a certain moment;

[0010] Daily fuel consumption after reducing the power of the main engine O PE And the daily fuel consumption of the main engine without reducing power O PEN , calculate the daily fuel consumption saved by sailing O S ;

[0011]

[0012] P EN =P E +P s ;

[0013]

[0014] Among them, P E To reduce the power output of the host, SFOC PE P E The corresponding unit fuel consumption of the main engine, Ps is the propulsion power of the sail, P EN SFOC is the power generated by the main engine when there is no sail. PEN P EN Corresponding host unit fuel consumption;

[0015] Corresponding to the data recorded by the control system, the expression is as follows:

[0016]

[0017] In summary, the data recorded by the sail control system can be used to calculate the daily fuel consumption saved by the sail.

[0018] The above method for obtaining fuel consumption saving of a sail based on measurement data further comprises the following steps: the sail is fixed on the main deck of the ship, and its fixing position is higher or lower than the main deck through structural reinforcement.

[0019] The above method for obtaining sail fuel consumption saving based on measurement data further comprises the following steps: the mast is divided into three sections: upper, middle and lower, and adopts a polygonal nested structure, wherein the uppermost section of the mast is the smallest and the lowermost section is the largest.

[0020] The above method for obtaining fuel saving of a sail based on measurement data further comprises the following steps: the sail surface is divided into three sections: upper, middle and lower, which are polygonal nested structures, with the lower section having the smallest size and the upper section having the largest size.

[0021] The above method for obtaining fuel-saving sails based on measurement data further comprises the following steps: each section of the mast corresponds to a sail surface, the mast and the sail surface are fixed on a slewing bearing, and a rotary motor drives the slewing bearing to rotate through a pinion, and the mast and the sail surface rotate together with the slewing bearing.

[0022] The above method for obtaining fuel consumption saving of a sail based on measurement data further comprises the following steps: the sail is fixed at a position within 3000 mm above or below the main deck.

[0023] The present invention proposes the principle of fuel saving by sails, that is, the fuel consumption corresponding to the total power is subtracted from the fuel consumption corresponding to the actual power output of the main engine; by using the information such as the main engine power, relative wind direction, relative wind speed, and ship speed recorded by the control system, the fuel consumption saved by the sail control system every day can be quickly evaluated. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of relative wind direction angle. DETAILED DESCRIPTION

[0025] The present invention will be further described with reference to the accompanying drawings.

[0026] A method based on measurement data to determine fuel savings using sails. Sailing propels a vessel forward by utilizing pressure differences across its cross-section. Typically, sails are mounted on the main deck of a vessel. Depending on project requirements, their installation position can be slightly above or below the main deck through structural reinforcement, with the specific value being within approximately 3,000 mm.

[0027] The mechanical structure of a sail consists of the mast, sail, base, slewing mechanism, and lifting mechanism. The mast and sail each consist of three sections, all nested in a polygonal structure. The mast's top section is the smallest, while the bottom section is the largest. The opposite is true for the sail, with the bottom section being the smallest and the top section being the largest, to accommodate lifting and lowering movements.

[0028] The slewing mechanism consists of a slewing base, a slewing bearing, a rotary motor and a pinion gear. The lifting structure is composed of a hydraulic cylinder and a pulley set.

[0029] The mast and the sail are fixed on the slewing bearing. The rotary motor drives the slewing bearing to rotate through the pinion, and the mast and the sail rotate together with it.

[0030] The mast is raised and lowered by hydraulic cylinders. Each section of the mast corresponds to the sail, and when the mast is raised or lowered, it also drives the sail to rise and fall.

[0031] The sail control system adapts to the ship's wind conditions, automatically controlling sail rotation based on relative wind direction and speed to provide maximum thrust. The control interface displays the sail's primary functions, including performance, status, and real-time energy-saving analysis. Crew members can control the sails from a control panel in the wheelhouse. In the event of an emergency, manual control panels are provided in the wheelhouse and near the sails for emergency lowering of the sails.

[0032] like Figure 1 As shown, A is the ship, B is the bow of the ship, and C is the stern of the ship. The relative wind is 0° when it comes from the bow of the ship. It rotates clockwise. When the wind direction is perpendicular to the length of the ship, it is 90°. When the wind comes from the stern of the ship, it is 180°. It continues to rotate. When the wind direction is perpendicular to the direction of the ship again, it is 270°. It continues to rotate until 360° coincides with 0°.

[0033] The data recorded by the sail control system is in seconds, and records information including main engine power, relative wind direction, relative wind speed, ship speed, etc. These data are needed to calculate the daily fuel consumption saved by the sail.

[0034] The wind-assisted propulsion system can determine its wind-assisted propulsion capability under the target ship type through wind tunnel tests and CFD. That is, different relative wind direction angles correspond to different thrust coefficients. This thrust coefficient is the inherent property of the sail-assisted propulsion system, and different sail-assisted propulsion systems also have different thrust coefficients.

[0035] When calculating the thrust provided by the sail to the ship, it is necessary to multiply the air density, sail area, relative wind speed, ship speed and thrust coefficient at a certain moment and divide it by 2 to get the thrust provided by the sail to the ship at a certain moment.

[0036] When a ship reaches a certain speed under certain sea conditions, it needs a certain amount of boost power. Due to the use of sails, the power output of the ship's main engine is reduced, thereby reducing daily fuel consumption. The main engine power recorded in the sail control system is actually the output power P after the addition of the sails. E According to the fuel consumption power curve, the daily fuel consumption after the main engine power is reduced can be calculated. In order to obtain the amount of daily fuel consumption reduction, it is necessary to know how much power the main engine would have generated if there was no sail propulsion system, that is, the propulsion power P provided by the sail. s The power P generated by the main engine after the sail is added E The sum of the two, through the fuel consumption power curve, is used to calculate the daily fuel consumption that the main engine should have, that is, the daily fuel consumption of the main engine if there was no sail propulsion system; the difference between the two calculated daily fuel consumptions is the daily fuel consumption saved by the sail.

[0037] Recording data from the sail control system.

[0038] The data recorded by the sail control system on October 10, 2024 is shown in the following table.

[0039]

[0040]

[0041] In the table, ii:ii:ii∈[00:00:00,23:59:59]

[0042] Boost power P of the sail boost system s

[0043] The sail-assisted propulsion system has different thrust coefficients at different relative wind direction angles, as shown in the following table.

[0044] Thrust coefficient of the sail propulsion system at different relative wind direction angles

[0045] 0° 5° 10° … θ° … 180° <![CDATA[α0]]> <![CDATA[α5]]> <![CDATA[α 10 ]]> … <![CDATA[α θ ]]> … <![CDATA[α 180 ]]>

[0046] In the table, θ∈[0,180].

[0047] Then the propulsion power of the sail propulsion system is expressed as follows:

[0048] P s =F s ·C (1)

[0049] Among them, P s Sail propulsion system power, F s is the thrust of the sail, and C is the ship's speed. s The expression is:

[0050]

[0051] where ρ a is the air density, V is the relative wind speed of the ship, A is the area of ​​the sail propulsion system, α θ is the thrust coefficient at a certain relative wind direction angle.

[0052] The propulsion power of the sail propulsion system converted to a certain moment is expressed as follows:

[0053]

[0054] Where Vii:ii:ii is the relative wind speed of the ship at a certain moment, αii:ii:ii is the thrust coefficient under a certain relative wind direction angle at a certain moment obtained by interpolation from Table 1, and Cii:ii:ii is the speed of the ship at a certain moment.

[0055] Daily fuel consumption after main engine power reduction O PE .

[0056] The daily fuel consumption after the host reduces power is 0 PE , the unit is kW, the output power of the host is P E , interpolate based on the fuel consumption and power curve provided by the host manufacturer, P E The corresponding host unit fuel consumption is SFOC PE , unit is g / kW·h. Different P corresponds to different SFOC, which should be obtained by interpolation based on the fuel consumption power curve provided by the host manufacturer. Then the corresponding daily fuel consumption is O PE The expression is:

[0057]

[0058] Daily fuel consumption without reducing the power of the main engine O PEN ;

[0059] If there is no sail, the power P generated by the main engine is EN The power output by the host should be reduced to P E and the boost power Ps of the sail, that is

[0060] P EN =P E +P s

[0061] The daily fuel consumption after the host reduces power is 0 PEN , interpolate based on the fuel consumption and power curve provided by the host manufacturer, P EN The corresponding host unit fuel consumption is SFOC PEN , then the daily fuel consumption of the corresponding host without reducing power is O PEN , the expression is:

[0062]

[0063] Daily fuel consumption saved by sailing O S .

[0064] The daily fuel consumption saved by using the sail is O S , then according to the above content, O S The expression is as follows:

[0065]

[0066] The expression for the data recorded by the control system is as follows. Since the unit of SFOC is per hour, and the data recorded by the control system is per second, it needs to be divided by 3600.

[0067]

[0068] In summary, the data recorded by the sail control system can be used to calculate the daily fuel consumption saved by the sail.

Claims

1. A method for obtaining fuel consumption savings of a sail based on measurement data, characterized in that: The boost power Psi of the sail boost system at a certain moment is obtained by converting the boost power Ps of the sail boost system and the boost force Fs of the sail; P s =F s ·C (1) Where C is the ship speed, ρa is the air density, V is the ship relative wind speed, A is the area of ​​the sail propulsion system, αθ is the thrust coefficient under a certain relative wind direction angle, Vii:ii:ii is the ship relative wind speed at a certain moment, αii:ii:ii is the thrust coefficient under a certain relative wind direction angle at a certain moment obtained by interpolation, and Cii:ii:ii is the ship speed at a certain moment; Daily fuel consumption after reducing the power of the main engine O PE And the daily fuel consumption of the main engine without reducing power O PEN , calculate the daily fuel consumption saved by sailing O S ; P EN =P E +P s ; Among them, P E To reduce the power output of the host, SFOC PE P E The corresponding unit fuel consumption of the main engine, Ps is the propulsion power of the sail, P EN SFOC is the power generated by the main engine when there is no sail. PEN P EN Corresponding host unit fuel consumption; Corresponding to the data recorded by the control system, the expression is as follows: In summary, the data recorded by the sail control system can be used to calculate the daily fuel consumption saved by the sail.

2. The method for obtaining sail fuel consumption savings based on measurement data according to claim 1, characterized in that: The sails are fixed to the main deck of the ship, and their fixed position is above or below the main deck through structural reinforcement.

3. The method for obtaining sail fuel consumption savings based on measurement data according to claim 1, characterized in that: The mast is divided into three sections: upper, middle and lower, and adopts a polygonal nested structure. The uppermost section of the mast is the smallest and the lowermost section is the largest.

4. The method for obtaining sail fuel consumption savings based on measurement data according to claim 1, characterized in that: The sail surface is divided into three sections: upper, middle and lower, with a polygonal nested structure. The bottom section is the smallest and the top section is the largest.

5. The method for obtaining sail fuel consumption savings based on measurement data according to claim 1, characterized in that: Each section of the mast corresponds to the sail surface one by one. The mast and the sail surface are fixed on the slewing bearing. The rotary motor drives the slewing bearing to rotate through the pinion, and the mast and the sail surface rotate together with it.

6. The method for obtaining sail fuel consumption savings based on measurement data according to claim 2, characterized in that: The sail fixing position is within 3000mm above or below the main deck.

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