CN111017136B - Ship fouling monitoring and evaluating method and evaluating system - Google Patents
Ship fouling monitoring and evaluating method and evaluating system Download PDFInfo
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- CN111017136B CN111017136B CN201911344796.1A CN201911344796A CN111017136B CN 111017136 B CN111017136 B CN 111017136B CN 201911344796 A CN201911344796 A CN 201911344796A CN 111017136 B CN111017136 B CN 111017136B
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Abstract
A ship bottom pollution monitoring and evaluating method and system firstly collect ship operation data including ship state data, then perform quality screening on the data, remove the data with large data fluctuation and low quality by analyzing the average value, the maximum and minimum value and the standard deviation of original data signals, and simultaneously screen the navigation wind and wave environment and the ship state to obtain the data suitable for analysis; then, the screened data is corrected for environmental factors, and the influence of wind, waves, flow and water temperature on the ship performance is corrected, so that ship performance data which are close to an ideal environment and contain the influence of the bottom of a pollutant on the ship performance are obtained; and finally, comparing the ship performance data corrected by the environmental factors with a ship performance standard, analyzing and fitting the difference between the ship performance data and the ship performance standard to obtain an evaluation result, namely a performance reduction percentage value caused by fouling, and giving a docking decontamination suggestion when the value reaches a certain threshold value.
Description
Technical Field
The invention relates to the technical field of ship fouling treatment, in particular to a ship fouling monitoring and evaluating method and system.
Background
In both ocean-going vessels and inland river vessels, aquatic life such as shellfish, algae, etc. inevitably adheres to the bottom of the vessel due to long-term sailing in water, and these bottom-adhering crops are called vessel bottom fouling.
The generation of ship fouling causes the roughness of the ship to be increased, the resistance of the ship is greatly increased, and further the fuel consumption of a ship main engine is increased. The monitoring and cleaning of ship fouling therefore has been the focus of attention for the world ship and shipping industries.
Since the occurrence of fouling in a ship is influenced by various factors, and the formation of the attachments on the bottom of the ship is influenced by the water temperature, the water speed, the sailing speed, and the like, the growth rates of the attachments on the bottom of different ships are different from each other, and the formation rates of the attachments on different sailing areas are different even in different periods of the same ship. The uncertainty of the growth rate of the attachments adversely affects the bottom treatment of the ship, and the cost for removing the attachments increases when the bottom attachments are treated too early, and the cost for operating the ship increases when the bottom attachments are treated too late.
In order to know the state of attachments of ships timely and accurately, two ship fouling monitoring means and technologies are mainly available at home and abroad at present: the first is a physical monitoring scheme of an on-board or shore-based monitoring device, such as underwater filming of a dirty floor by divers or by a fully submerged underwater robot. The second is by software monitoring evaluation methods. The physical monitoring and evaluation method needs a large amount of manpower and material resources, and the evaluation method has high cost and complex process. The existing software monitoring and evaluating method does not exclude low-quality data, so that the evaluating effect is influenced; influences of environmental factors such as wind waves and the like are not considered, so that evaluation result deviation is caused; the influence of different trim on the performance evaluation of the ship cannot be considered, so that the fouling evaluation is not accurate enough.
The invention is provided for overcoming the defects in the prior art.
Disclosure of Invention
The invention aims to provide a ship fouling monitoring and evaluating method and a ship fouling monitoring and evaluating system aiming at the structural defects in the prior art, which can monitor and evaluate the ship fouling and give a fouling cleaning suggestion in time by monitoring the ship navigation performance and analyzing and calculating the influence caused by the ship fouling. .
In order to achieve the above object, the first proposed ship fouling monitoring and evaluating method in the embodiments of the present invention is implemented by the following technical solutions:
the ship fouling monitoring and evaluating method is characterized by comprising the following steps:
the method comprises the following steps of collecting ship operation data: ship draft, speed host power, speed host rotating speed, ship to ground speed, ship to water speed, ship rudder angle, ship heading angle, ship motion and navigation environment;
secondly, performing quality screening on the data acquired in the first step; firstly, carrying out time segmentation processing on the data to convert the data into a plurality of fixed time period data with a set time length, thereby converting a higher frequency signal into a time average signal; then, carrying out statistical analysis on the fixed time period data to obtain statistical values of absolute values, maximum and minimum values and standard deviations of the fixed time period data; then, by analyzing the obtained average value, the maximum value, the minimum value and the standard deviation, removing low-quality data with large jitter and instability, and screening the navigation storm environment and the ship state to obtain data suitable for analysis;
thirdly, correcting environmental factors of the data screened in the second step, and correcting the influence of wind, wave, flow and water temperature on the ship performance to obtain ship performance data containing the influence of the bottom of the water on the ideal conditions of no wind, no wave, no flow and standard water temperature;
comparing the ship performance data corrected by the environmental factors with a ship performance standard, and analyzing and fitting the difference between the ship performance data and the ship performance standard to obtain a performance reduction percentage value caused by fouling; when the performance reduction percentage value reaches a set threshold value, a docking decontamination recommendation is given.
The specific mode of performing quality screening on the data acquired in the step one in the step two is as follows:
A. calculating the standard deviation of the data of the fixed time period, and screening out the data with large standard deviation and poor stability, including but not limited to: the standard deviation of the rotating speed is more than 1 revolution/minute, the standard deviation of the navigational speed is more than 0.5 section, the standard deviation of the first-direction angle is more than 3 degrees, the standard deviation of the rudder angle is more than 3 degrees, and the standard deviation of the wind direction angle is more than 15 degrees; and simultaneously screen out data with large ship motion, including but not limited to: the standard difference of the rolling angle of the ship is more than 20 degrees, and the standard difference of the pitching angle of the ship is more than 3 degrees;
B. calculating the absolute value, maximum and minimum value of the fixed time period data, and screening out data with large jitter or distortion, including but not limited to: the difference between the maximum value and the minimum value of the rotating speed is more than 3 revolutions per minute, and the maximum absolute value of the rudder angle is more than 5 degrees;
C. calculating the average value of the data of the fixed time period, screening the average values of the water depth, the wind speed, the wave height and the navigational speed, and screening out the data of shallow water, large wind wave and small navigational speed, including but not limited to: the water depth is less than 100 meters, the navigational speed is less than 8 knots, the wind speed is more than 25 knots, and the wave height is more than 3 meters.
The third step comprises the following specific steps: according to the formula
Calculating the wind resistance of the ship according to the formula
Calculating wave drag and according to formula
Calculating water temperature resistance increase, converting the total resistance increase obtained by calculation into power increase, subtracting the power increase from the initial host power to obtain corrected host power, and correcting the rotating speed according to the corresponding relation between the host power and the rotating speed; correcting the ship speed by using the longitudinal flow velocity of the ship, which is measured by a log, wherein the initial speed of the ship plus the longitudinal flow velocity is the corrected ship speed;
in the above formula: rhoaIs the density of air, AxvIs the frontal area of the ship, CaaFor the wind resistance coefficient, it can be obtained by empirical formula, or wind tunnel test data, V, similar to the ship type can be usedgFor the ground speed, V, of the vesselwWhich is the wind speed,
is the angle of wind direction, Caa(0) The wind resistance coefficient is the wind resistance coefficient when the wind direction angle is 0 degrees; rhosIs water density, H1/3Is the sense wave height, B is the width of the ship, LbwlThe distance from the bow to the position with the width of 95 percent of the ship on the water plane, and g is the gravity acceleration; s is the wet surface area of the ship, VsFor the speed of the ship on water, CfAnd Cf0The actual water temperature and the 15-degree water temperature correspond to the ship friction resistance coefficient respectively.
The corrected host power is calculated by: psc＝Ps-(Raa+Raw+Ras)·Vs/ηd(ii) a The corrected host rotation speed is calculated by the following formula:
wherein P issAnd NsFor initial main engine power and speed before correction, VsFor the speed of the ship in water, etadThe efficiency of ship propulsion is improved.
The fourth step comprises the following specific steps:
A. firstly, obtaining a ship performance standard through a ship multi-loading-condition model test, wherein the ship performance standard comprises ship main engine power, rotating speed and ship navigational speed under different drafts and trim of a ship;
B. by using the ship performance standard, the ship ideal performance data under the same working condition as the monitored ship performance data is interpolated, namely the ideal main engine power P of the ship under the same fore-aft draft and navigation speed is calculatedsiAnd a rotational speed Nsi；
C. Calculating the ratio C of the corrected ship power and the ideal ship power of actual monitoringpI.e. Cp＝Psc/Psi(ii) a And using the ratio CpCarrying out ship fouling influence fitting calculation;
D. according to the historical record of the ship cleaning time, for CpGrouping the values, one group is formed between two times of decontamination, and the data and C of each group are comparedpPerforming straight line fitting to obtain CpThe change condition of the sample is changed along with the time, and the evaluation result is given.
In addition, an embodiment of the present invention further provides a ship fouling monitoring and evaluating system, where the system includes:
the data acquisition platform is used for acquiring ship operation data including ship draft, speed host power, speed host rotating speed, ship to ground speed, ship to water speed, ship rudder angle, ship heading angle, ship motion and navigation environment;
the data screening module is used for screening the quality of the ship operation data acquired by the data acquisition platform to remove low-quality data with large jitter and instability and screening the navigation stormy environment and the ship state;
the environmental factor correction module is used for processing the data screened by the data screening module and correcting the influence of wind, wave, flow and water temperature on the ship performance so as to obtain ship performance data containing the influence of the bottom of a river under the ideal conditions of no wind, no wave, no flow and standard water temperature;
the fouling calculation module is used for comparing the ship performance data corrected by the environmental factor correction module with a ship performance standard, and analyzing and fitting the difference between the ship performance data and the ship performance standard to obtain a performance reduction percentage value caused by fouling; and when the value reaches the set threshold value of the bottom calculating module, a docking station decontamination suggestion is given.
The data screening module comprises:
the time segmentation processing unit is used for respectively carrying out time segmentation processing on the ship operation data so as to convert the ship operation data into a plurality of fixed time period data with a set duration, and therefore, a higher frequency signal is converted into a time average signal;
and the standard deviation calculating unit is used for calculating the standard deviation of the data in the fixed time period and screening out the data with larger standard deviation and poorer stability, and the standard deviation calculating unit comprises but is not limited to: the standard deviation of the rotating speed is more than 1 revolution/minute, the standard deviation of the navigational speed is more than 0.5 section, the standard deviation of the first-direction angle is more than 3 degrees, the standard deviation of the rudder angle is more than 3 degrees, and the standard deviation of the wind direction angle is more than 15 degrees; and simultaneously screen out data with large ship motion, including but not limited to: the standard difference of the rolling angle of the ship is more than 20 degrees, and the standard difference of the pitching angle of the ship is more than 3 degrees;
an absolute value and maximum and minimum value calculating unit, configured to calculate an absolute value and a maximum and minimum value of the fixed time period data, and screen out data with large jitter or distortion, including but not limited to: the difference between the maximum value and the minimum value of the rotating speed is more than 3 revolutions per minute, and the maximum absolute value of the rudder angle is more than 5 degrees;
an average value calculation unit for calculating an average value of the fixed time period data; and screening the average values of water depth, wind speed, wave height and navigational speed, and screening out data of shallow water, large wind wave and small navigational speed, including but not limited to: the water depth is less than 100 meters, the navigational speed is less than 8 knots, the wind speed is more than 25 knots, and the wave height is more than 3 meters.
The environmental factor correction module comprises:
a ship wind resistance calculation unit for calculating the wind resistance according to the formula
Calculating the wind resistance of the ship; where ρ isaIs the density of air, AxvIs the frontal area of the ship, CaaFor the wind resistance coefficient, it can be obtained by empirical formula, or wind tunnel test data, V, similar to the ship type can be usedgFor the ground speed, V, of the vesselwWhich is the wind speed,
is the angle of wind direction, Caa(0) The wind resistance coefficient is the wind resistance coefficient when the wind direction angle is 0 degrees;
a wave resistance-increasing calculating unit for calculating the wave resistance-increasing value according to a formula
Calculating the wave resistance increase; where ρ issIs water density, H1/3Is the sense wave height, B is the width of the ship, LbwlThe distance from the bow to the position with the width of 95 percent of the ship on the water plane, and g is the gravity acceleration;
a water temperature resistance-increasing calculating unit for calculating the water temperature resistance-increasing value according to a formula
Calculating the water temperature increase resistance, wherein rhosIs water density, S is wet surface area of ship, VsFor the speed of the ship on water, CfAnd Cf0The actual water temperature and the 15-degree water temperature correspond to the ship friction resistance coefficient respectively;
a host power correction unit for correcting the power of the host by the formula Psc＝Ps-(Raa+Raw+Ras)·Vs/ηdCalculating the corrected host power;
a main machine rotation speed correction unit for passing the formula
Calculating the corrected rotating speed of the host;
wherein P issAnd NsFor initial main engine power and speed before correction, VsFor the speed of the ship in water, etadThe efficiency of ship propulsion is improved.
The dirty bottom calculation module includes:
the system comprises a ship performance reference interpolation unit, a ship performance reference interpolation unit and a ship performance reference interpolation unit, wherein the ship performance reference interpolation unit is internally provided with ship performance reference data obtained based on a ship multi-loading-condition model test and comprises ship main engine power, rotating speed and ship navigational speed under different draughts and trim of a ship; the ship performance reference interpolation unit is used for carrying out interpolation calculation on ship ideal performance data under the same working condition with the monitored ship performance data based on the ship performance reference data, namely calculating the ideal main engine power P of the ship under the same fore-aft draught and the same navigational speedsiAnd a rotational speed Nsi；
Dimensionless value of CpA calculating unit for calculating the ratio C of the corrected ship power to the ideal ship power of the actual monitoringpI.e. Cp＝Psc/Psi(ii) a And using the dimensionless value CpCarrying out ship fouling influence fitting calculation;
a fitting unit for fitting C according to the historical trash cleaning time record of the shippGrouping the values, one group is formed between two times of decontamination, and the data and C of each group are comparedpPerforming straight line fitting to obtain CpThe change condition of the sample is changed along with the time, and the evaluation result is given.
In the embodiment of the present invention, when the ship operation data is processed as described above, the set time length of the obtained fixed time period data is 10 minutes.
Compared with the prior art, the invention has the beneficial effects that: and a data quality evaluation and screening method is established, data with low quality and data which are not suitable for analysis in the ship navigation environment and the ship navigation state are removed, high-quality monitoring data are reserved for analysis, and the evaluation effect is ensured. And establishing a method for correcting the influence of environmental factors such as wind waves and the like, and eliminating the influence of the environmental factors on the ship performance and the bottom pollution evaluation. The method comprises the steps of establishing performance benchmarks of ships under different drafts and different trim by utilizing multi-load condition model test data, obtaining unified dimensionless coefficients under different load conditions through comparison and calculation of operation monitoring data and the benchmarks, and carrying out fitting analysis to obtain a more accurate fouling influence percentage value. The scheme can effectively liberate manpower and material resources, improve safety, ensure the reliability of the acquisition system and have good economy.
Drawings
The above features and advantages of the present invention will become more apparent and readily appreciated from the following description of the exemplary embodiments thereof taken in conjunction with the accompanying drawings.
FIG. 1 is a flow chart of an overall scheme of a contamination monitoring and evaluation system according to an embodiment of the present invention;
FIG. 2 is a data quality screening flowchart of a ship fouling monitoring and evaluating method according to an embodiment of the present invention;
FIG. 3 is a flowchart of correcting environmental factors in a ship fouling monitoring and evaluating method according to an embodiment of the present invention;
FIG. 4 is a flowchart of a fouling calculation and evaluation method for monitoring and evaluating fouling of a ship according to an embodiment of the present invention;
fig. 5 is a schematic view of the fitting evaluation of the influence of the contamination given by the contamination monitoring and evaluating system according to the embodiment of the present invention.
Detailed Description
The invention is described in further detail below with reference to the attached drawing figures to facilitate understanding by those skilled in the art:
referring to fig. 1 to 5, an embodiment of the present invention first provides a ship fouling monitoring and evaluating method, which is implemented by the following technical solutions:
the method comprises the following steps of collecting ship operation data: ship draft, speed host power, speed host rotating speed, ship to ground speed, ship to water speed, ship rudder angle, ship heading angle, ship motion and navigation environment;
secondly, performing quality screening on the data acquired in the first step; firstly, carrying out time segmentation processing on the data by taking every ten minutes as a fixed time period so as to convert a higher-frequency signal into a time average signal; carrying out statistical analysis on data in the average time period to obtain an absolute value, a maximum and minimum value and a standard deviation statistical value; then, by analyzing the average value, the maximum value, the minimum value, the standard deviation and the like of the data, removing low-quality data with large jitter and instability, and screening the navigation storm environment and the ship state to obtain data suitable for analysis;
the specific screening mode is as follows:
A. calculating the standard deviation of the data in ten minutes, and screening out the data with large standard deviation and poor stability, including but not limited to: the standard deviation of the rotating speed is more than 1 revolution/minute, the standard deviation of the navigational speed is more than 0.5 section, the standard deviation of the first-direction angle is more than 3 degrees, the standard deviation of the rudder angle is more than 3 degrees, and the standard deviation of the wind direction angle is more than 15 degrees; and simultaneously screen out data with large ship motion, including but not limited to: the standard difference of the rolling angle of the ship is more than 20 degrees, and the standard difference of the pitching angle of the ship is more than 3 degrees;
B. calculating the absolute value, maximum and minimum value of the data in ten minutes, and screening out the data with large jitter or distortion, including but not limited to: the difference between the maximum value and the minimum value of the rotating speed is more than 3 revolutions per minute, and the maximum absolute value of the rudder angle is more than 5 degrees;
C. calculating the average value of ten minutes data, and screening the average values of water depth, wind speed, wave height and navigation speed to screen out the data of shallow water, large wind wave and small navigation speed, including but not limited to: the water depth is less than 100 meters, the navigational speed is less than 8 knots, the wind speed is more than 25 knots, and the wave height is more than 3 meters.
Thirdly, correcting environmental factors of the data screened in the second step, and correcting the influence of wind, wave, flow and water temperature on the ship performance to obtain ship performance data containing the influence of the bottom of the water on the ideal conditions of no wind, no wave, no flow and standard water temperature;
the specific correction mode is as follows: according to the formula
Calculating the wind resistance of the ship according to the formula
Calculating wave drag and according to formula
Calculating water temperature resistance increase, converting the total resistance increase obtained by calculation into power increase, subtracting the power increase from the initial host power to obtain corrected host power, and correcting the rotating speed according to the corresponding relation between the host power and the rotating speed; correcting the ship speed by using the longitudinal flow velocity of the ship, which is measured by a log, wherein the initial speed of the ship plus the longitudinal flow velocity is the corrected ship speed;
in the above formula: rhoaIs the density of air, AxvIs the frontal area of the ship, CaaFor the wind resistance coefficient, it can be obtained by empirical formula, or wind tunnel test data, V, similar to the ship type can be usedgFor the ground speed, V, of the vesselwWhich is the wind speed,
is the wind direction angle; rhosIs water density, H1/3Is the sense wave height, B is the width of the ship, LbwlThe distance from the bow to the position with the width of 95 percent of the ship on the water plane, and g is the gravity acceleration; s is the wet surface area of the ship, VsFor the speed of the ship on water, CfAnd Cf0The actual water temperature and the 15-degree water temperature correspond to the ship friction resistance coefficient respectively.
The corrected host power is calculated by: psc＝Ps-(Raa+Raw+Ras)·Vs/ηd(ii) a The corrected host rotation speed is calculated by the following formula:
wherein P issAnd NsFor initial main engine power and speed before correction, VsFor the speed of the ship in water, etadThe efficiency of ship propulsion is improved.
Comparing the ship performance data corrected by the environmental factors with a ship performance standard, and analyzing and fitting the difference between the ship performance data and the ship performance standard to obtain a performance reduction percentage value caused by fouling; when the value reaches a set threshold value, a docking station decontamination proposal is given. The method comprises the following specific steps:
A. firstly, obtaining a ship performance standard through a ship multi-loading-condition model test, wherein the ship performance standard comprises ship main engine power, rotating speed and ship navigational speed under different drafts and trim of a ship;
B. by using the ship performance standard, the ship ideal performance data under the same working condition as the monitored ship performance data is interpolated, namely the ideal main engine power P of the ship under the same fore-aft draft and navigation speed is calculatedsiAnd a rotational speed Nsi；
C. Calculating the ratio C of the corrected ship power and the ideal ship power of actual monitoringpI.e. Cp＝Psc/Psi(ii) a And using the ratio CpCarrying out ship fouling influence fitting calculation;
D. according to the historical record of the ship cleaning time, for CpGrouping the values, one group is formed between two times of decontamination, and the data and C of each group are comparedpPerforming straight line fitting to obtain CpThe change condition of the sample is changed along with the time, and the evaluation result is given.
In addition, an embodiment of the present invention further provides a ship fouling monitoring and evaluating system, where the system includes:
data screening module
The data screening module is used for carrying out quality screening on the ship operation data; the vessel operation data includes: ship draft, speed host power, speed host rotational speed, ship speed to ground, ship speed to water, ship rudder angle, ship heading angle, ship motion, and navigation environment.
The data screening module comprises:
the time segmentation processing unit is used for performing time segmentation processing on the ship operation data by taking ten minutes as a fixed time period so as to convert a higher frequency signal into a time average signal;
and the standard deviation calculating unit is used for calculating the standard deviation of the ship operation data within ten minutes and screening out data with larger standard deviation and poorer stability, and comprises but is not limited to: the standard deviation of the rotating speed is more than 1 revolution/minute, the standard deviation of the navigational speed is more than 0.5 section, the standard deviation of the first-direction angle is more than 3 degrees, the standard deviation of the rudder angle is more than 3 degrees, and the standard deviation of the wind direction angle is more than 15 degrees; and simultaneously screen out data with large ship motion, including but not limited to: the standard difference of the rolling angle of the ship is more than 20 degrees, and the standard difference of the pitching angle of the ship is more than 3 degrees;
and the absolute value and maximum and minimum value calculating unit is used for calculating the absolute value and the maximum and minimum value of the ship operation data in ten minutes, and screening out data with large jitter or distortion, and comprises but is not limited to: the difference between the maximum value and the minimum value of the rotating speed is more than 3 revolutions per minute, and the maximum absolute value of the rudder angle is more than 5 degrees;
an average value calculation unit for calculating an average value of ten minutes of ship operation data; and screening the average values of water depth, wind speed, wave height and navigational speed, and screening out data of shallow water, large wind wave and small navigational speed, including but not limited to: the water depth is less than 100 meters, the navigational speed is less than 8 knots, the wind speed is more than 25 knots, and the wave height is more than 3 meters.
Environmental factor correction module
The environmental factor correction module is used for processing the data screened by the data screening module and correcting the influence of wind, wave, flow and water temperature on the ship performance so as to obtain the ship performance data containing the influence of the bottom of a stain under the ideal conditions of no wind, no wave, no flow and standard water temperature.
The environmental factor correction module comprises:
a ship wind resistance calculation unit for calculating the wind resistance according to the formula
Calculating the wind resistance of the ship; where ρ isaIs the density of air, AxvIs the frontal area of the ship, CaaFor the wind resistance coefficient, it can be obtained by empirical formula, or wind tunnel test data, V, similar to the ship type can be usedgFor the ground speed, V, of the vesselwWhich is the wind speed,
is the angle of wind direction, Caa(0) The wind resistance coefficient is the wind resistance coefficient when the wind direction angle is 0 degrees;
a wave resistance-increasing calculating unit for calculating the wave resistance-increasing value according to a formula
Calculating the wave resistance increase; where ρ issIs water density, H1/3Is the sense wave height, B is the width of the ship, LbwlThe distance from the bow to the position with the width of 95 percent of the ship on the water plane, and g is the gravity acceleration;
a water temperature resistance-increasing calculating unit for calculating the water temperature resistance-increasing value according to a formula
Calculating the water temperature increase resistance, wherein rhosIs water density, S is wet surface area of ship, VsFor the speed of the ship on water, CfAnd Cf0The actual water temperature and the 15-degree water temperature correspond to the ship friction resistance coefficient respectively;
a host power correction unit for correcting the power of the host by the formula Psc＝Ps-(Raa+Raw+Ras)·Vs/ηdCalculating the corrected host power;
a main machine rotation speed correction unit for passing the formula
Calculating the corrected rotating speed of the host;
wherein P issAnd NsFor initial main engine power and speed before correction, VsFor the speed of the ship in water, etadThe efficiency of ship propulsion is improved.
Dirty bottom calculating module
The fouling calculation module is used for comparing ship performance data corrected by the environmental factor correction module with a ship performance standard, and analyzing and fitting the difference between the ship performance data and the ship performance standard to obtain a performance reduction percentage value caused by fouling; and when the value reaches the set threshold value of the bottom calculating module, a docking station decontamination suggestion is given.
The dirty bottom calculation module includes:
the ship performance reference interpolation unit is internally provided with ship performance reference data obtained based on a ship multi-loading-condition model test and comprises ship owners with different drafts and trim of shipsPower, rotating speed and ship speed; the ship performance reference interpolation unit is used for carrying out interpolation calculation on ship ideal performance data under the same working condition with the monitored ship performance data based on the ship performance reference data, namely calculating the ideal main engine power P of the ship under the same fore-aft draught and the same navigational speedsiAnd a rotational speed Nsi；
Dimensionless value of CpA calculating unit for calculating the ratio C of the corrected ship power to the ideal ship power of the actual monitoringpI.e. Cp＝Psc/Psi(ii) a And using the dimensionless value CpCarrying out ship fouling influence fitting calculation;
a fitting unit for fitting C according to the historical trash cleaning time record of the shippGrouping the values, one group is formed between two times of decontamination, and the data and C of each group are comparedpPerforming straight line fitting to obtain CpThe change condition of the sample is changed along with the time, and the evaluation result is given.
Compared with the prior art, the invention has the beneficial effects that: and a data quality evaluation and screening method is established, data with low quality and data which are not suitable for analysis in the ship navigation environment and the ship navigation state are removed, high-quality monitoring data are reserved for analysis, and the evaluation effect is ensured. And establishing a method for correcting the influence of environmental factors such as wind waves and the like, and eliminating the influence of the environmental factors on the ship performance and the bottom pollution evaluation. The method comprises the steps of establishing performance benchmarks of ships under different drafts and different trim by utilizing multi-load condition model test data, obtaining unified dimensionless coefficients under different load conditions through comparison and calculation of operation monitoring data and the benchmarks, and carrying out fitting analysis to obtain a more accurate fouling influence percentage value. The scheme can effectively liberate manpower and material resources, improve safety, ensure the reliability of the acquisition system and have good economy.
Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that the above embodiments are only one of the preferred embodiments of the present invention, and not all embodiments can be enumerated herein for the sake of brevity, and any embodiment that can embody the claims of the present invention is within the protection scope of the present invention.
Claims (9)
1. A ship fouling monitoring and evaluating method comprises the following steps:
the method comprises the following steps of collecting ship operation data: ship draft, speed host power, speed host rotating speed, ship to ground speed, ship to water speed, ship rudder angle, ship heading angle, ship motion and navigation environment;
secondly, performing quality screening on the data acquired in the first step; firstly, carrying out time segmentation processing on the data to convert the data into a plurality of fixed time period data with a set time length, thereby converting a higher frequency signal into a time average signal; then, carrying out statistical analysis on the fixed time period data to obtain statistical values of absolute values, maximum and minimum values and standard deviations of the fixed time period data; then, by analyzing the obtained average value, the maximum value, the minimum value and the standard deviation, removing low-quality data with large jitter and instability, and screening the navigation storm environment and the ship state to obtain data suitable for analysis;
thirdly, correcting environmental factors of the data screened in the second step, and correcting the influence of wind, wave, flow and water temperature on the ship performance to obtain ship performance data containing the influence of the bottom of the water on the ideal conditions of no wind, no wave, no flow and standard water temperature;
comparing the ship performance data corrected by the environmental factors with a ship performance standard, and analyzing and fitting the difference between the ship performance data and the ship performance standard to obtain a performance reduction percentage value caused by fouling; when the performance reduction percentage value reaches a set threshold value, a docking station decontamination suggestion is given;
the method is characterized in that:
the third step comprises the following specific steps: according to the formula
Calculating the wind resistance of the ship according to the formula
Calculating wave drag and according to formula
Calculating water temperature resistance increase, converting the total resistance increase obtained by calculation into power increase, subtracting the power increase from the initial host power to obtain corrected host power, and correcting the rotating speed according to the corresponding relation between the host power and the rotating speed; correcting the ship speed by using the longitudinal flow velocity of the ship, which is measured by a log, wherein the initial speed of the ship plus the longitudinal flow velocity is the corrected ship speed;
in the above formula: rhoaIs the density of air, AxvIs the frontal area of the ship, CaaFor the wind resistance coefficient, it is obtained by empirical formula, or it is obtained by using wind tunnel test data, V, similar to the ship typegFor the ground speed, V, of the vesselwWhich is the wind speed,
is the angle of wind direction, Caa(0) The wind resistance coefficient is the wind resistance coefficient when the wind direction angle is 0 degrees; rhosIs water density, H1/3Is the sense wave height, B is the width of the ship, LbwlThe distance from the bow to the position with the width of 95 percent of the ship on the water plane, and g is the gravity acceleration; s is the wet surface area of the ship, VsFor the speed of the ship on water, CfAnd Cf0The actual water temperature and the 15-degree water temperature correspond to the ship friction resistance coefficient respectively.
2. The ship fouling monitoring and evaluating method according to claim 1, wherein the specific manner of performing quality screening on the data collected in the first step in the second step is as follows:
A. calculating the standard deviation of the data of the fixed time period, and screening out the data with large standard deviation and poor stability, including but not limited to: the standard deviation of the rotating speed is more than 1 revolution/minute, the standard deviation of the navigational speed is more than 0.5 section, the standard deviation of the first-direction angle is more than 3 degrees, the standard deviation of the rudder angle is more than 3 degrees, and the standard deviation of the wind direction angle is more than 15 degrees; and simultaneously screen out data with large ship motion, including but not limited to: the standard difference of the rolling angle of the ship is more than 20 degrees, and the standard difference of the pitching angle of the ship is more than 3 degrees;
B. calculating the absolute value, maximum and minimum value of the fixed time period data, and screening out data with large jitter or distortion, including but not limited to: the difference between the maximum value and the minimum value of the rotating speed is more than 3 revolutions per minute, and the maximum absolute value of the rudder angle is more than 5 degrees;
C. calculating the average value of the data of the fixed time period, screening the average values of the water depth, the wind speed, the wave height and the navigational speed, and screening out the data of shallow water, large wind wave and small navigational speed, including but not limited to: the water depth is less than 100 meters, the navigational speed is less than 8 knots, the wind speed is more than 25 knots, and the wave height is more than 3 meters.
3. The ship fouling monitoring and evaluation method according to claim 2, characterized in that: the corrected host power is calculated by: psc＝Ps-(Raa+Raw+Ras)·Vs/ηd(ii) a The corrected host rotation speed is calculated by the following formula:
wherein Ps and Ns are the initial main engine power and rotation speed before correction, VsFor the speed of the ship in water, etadThe efficiency of ship propulsion is improved.
4. The ship fouling monitoring and evaluating method according to claim 3, wherein the fourth specific step is:
A. firstly, obtaining a ship performance standard through a ship multi-loading-condition model test, wherein the ship performance standard comprises ship main engine power, rotating speed and ship navigational speed under different drafts and trim of a ship;
B. by using the ship performance standard, the ship ideal performance data under the same working condition as the monitored ship performance data is interpolated, namely the ideal main engine power P of the ship under the same fore-aft draft and navigation speed is calculatedsiAnd a rotational speed Nsi；
C. Calculating the ratio C of the corrected ship power and the ideal ship power of actual monitoringpI.e. Cp＝Psc/Psi(ii) a And using the ratio CpCarrying out ship fouling influence fitting calculation;
D. according to the historical record of the ship cleaning time, for CpGrouping the values, one group is formed between two times of decontamination, and the data and C of each group are comparedpPerforming straight line fitting to obtain CpThe change condition of the sample is changed along with the time, and the evaluation result is given.
5. A ship fouling monitoring and evaluation system, the system comprising:
the data acquisition platform is used for acquiring ship operation data including ship draft, speed host power, speed host rotating speed, ship to ground speed, ship to water speed, ship rudder angle, ship heading angle, ship motion and navigation environment;
the data screening module is used for screening the quality of the ship operation data acquired by the data acquisition platform to remove low-quality data with large jitter and instability and screening the navigation stormy environment and the ship state;
the environmental factor correction module is used for processing the data screened by the data screening module and correcting the influence of wind, wave, flow and water temperature on the ship performance so as to obtain ship performance data containing the influence of the bottom of a river under the ideal conditions of no wind, no wave, no flow and standard water temperature;
the fouling calculation module is used for comparing the ship performance data corrected by the environmental factor correction module with a ship performance standard, and analyzing and fitting the difference between the ship performance data and the ship performance standard to obtain a performance reduction percentage value caused by fouling; when the value reaches the set threshold value of the bottom calculating module, a docking station decontamination suggestion is given;
the method is characterized in that:
the environmental factor correction module comprises:
a ship wind resistance calculation unit for calculating the wind resistance according to the formula
Calculating the wind resistance of the ship; where ρ isaIs the density of air, AxvIs the frontal area of the ship, CaaFor the wind resistance coefficient, it is obtained by empirical formula, or it is obtained by using wind tunnel test data, V, similar to the ship typegFor the ground speed, V, of the vesselwWhich is the wind speed,
is the angle of wind direction, Caa(0) The wind resistance coefficient is the wind resistance coefficient when the wind direction angle is 0 degrees;
a wave resistance-increasing calculating unit for calculating the wave resistance-increasing value according to a formula
Calculating the wave resistance increase; where ρ issIs water density, H1/3Is the sense wave height, B is the width of the ship, LbwlThe distance from the bow to the position with the width of 95 percent of the ship on the water plane, and g is the gravity acceleration;
a water temperature resistance-increasing calculating unit for calculating the water temperature resistance-increasing value according to a formula
Calculating the water temperature resistance increase, wherein S is the wet surface area of the ship and VsFor the speed of the ship on water, CfAnd Cf0The actual water temperature and the 15-degree water temperature correspond to the ship friction resistance coefficient respectively;
a host power correction unit for correcting the power of the host by the formula Psc＝Ps-(Raa+Raw+Ras)·Vs/ηdCalculating the corrected host power;
a main machine rotation speed correction unit for passing the formula
Calculating the corrected rotating speed of the host;
wherein P issAnd NsFor initial main engine power and speed before correction, VsFor the speed of the ship in water, etadThe efficiency of ship propulsion is improved.
6. The ship fouling monitoring and evaluation system according to claim 5, characterized in that: the data screening module comprises:
the time segmentation processing unit is used for respectively carrying out time segmentation processing on the ship operation data so as to convert the ship operation data into a plurality of fixed time period data with a set duration, and therefore, a higher frequency signal is converted into a time average signal;
and the standard deviation calculating unit is used for calculating the standard deviation of the data in the fixed time period and screening out the data with larger standard deviation and poorer stability, and the standard deviation calculating unit comprises but is not limited to: the standard deviation of the rotating speed is more than 1 revolution/minute, the standard deviation of the navigational speed is more than 0.5 section, the standard deviation of the first-direction angle is more than 3 degrees, the standard deviation of the rudder angle is more than 3 degrees, and the standard deviation of the wind direction angle is more than 15 degrees; and simultaneously screen out data with large ship motion, including but not limited to: the standard difference of the rolling angle of the ship is more than 20 degrees, and the standard difference of the pitching angle of the ship is more than 3 degrees;
an absolute value and maximum and minimum value calculating unit, configured to calculate an absolute value and a maximum and minimum value of the fixed time period data, and screen out data with large jitter or distortion, including but not limited to: the difference between the maximum value and the minimum value of the rotating speed is more than 3 revolutions per minute, and the maximum absolute value of the rudder angle is more than 5 degrees;
an average value calculation unit for calculating an average value of the fixed time period data; and screening the average values of water depth, wind speed, wave height and navigational speed, and screening out data of shallow water, large wind wave and small navigational speed, including but not limited to: the water depth is less than 100 meters, the navigational speed is less than 8 knots, the wind speed is more than 25 knots, and the wave height is more than 3 meters.
7. The ship fouling monitoring and evaluation system according to claim 6, wherein the fouling calculation module comprises:
the system comprises a ship performance reference interpolation unit, a ship performance reference interpolation unit and a ship performance reference interpolation unit, wherein the ship performance reference interpolation unit is internally provided with ship performance reference data obtained based on a ship multi-loading-condition model test and comprises ship main engine power, rotating speed and ship navigational speed under different draughts and trim of a ship;the ship performance reference interpolation unit is used for carrying out interpolation calculation on ship ideal performance data under the same working condition with the monitored ship performance data based on the ship performance reference data, namely calculating the ideal main engine power P of the ship under the same fore-aft draught and the same navigational speedsiAnd a rotational speed Nsi；
Dimensionless value of CpA calculating unit for calculating the ratio C of the corrected ship power to the ideal ship power of the actual monitoringpI.e. Cp＝Psc/Psi(ii) a And using the dimensionless value CpCarrying out ship fouling influence fitting calculation;
a fitting unit for fitting C according to the historical trash cleaning time record of the shippGrouping the values, one group is formed between two times of decontamination, and the data and C of each group are comparedpPerforming straight line fitting to obtain CpThe change condition of the sample is changed along with the time, and the evaluation result is given.
8. The ship fouling monitoring and evaluation method according to any one of claims 1 to 4, characterized in that: the set time of the fixed time period data is 10 minutes.
9. The ship fouling monitoring and evaluation system according to any one of claims 6 to 7, characterized in that: the set time of the fixed time period data is 10 minutes.
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| CN111806645B (en) * | 2020-07-10 | 2022-04-05 | 上海船舶研究设计院（中国船舶工业集团公司第六0四研究院） | Ship decontamination method and device and electronic equipment |
| CN112162558A (en) * | 2020-09-29 | 2021-01-01 | 广州海事科技有限公司 | Ship safe navigational speed control method, system, computer equipment and storage medium |
| CN112141293B (en) * | 2020-09-30 | 2021-08-31 | 震兑工业智能科技有限公司 | Ship fouling monitoring and evaluating method based on fixed navigational speed fouling coefficient |
| CN112208728B (en) * | 2020-09-30 | 2021-11-09 | 震兑工业智能科技有限公司 | Ship fouling monitoring and early warning method |
| CN112093004B (en) * | 2020-09-30 | 2021-08-31 | 震兑工业智能科技有限公司 | Ship fouling monitoring and evaluating method based on overall fouling coefficient |
| CN112347423A (en) * | 2020-10-27 | 2021-02-09 | 上汽通用五菱汽车股份有限公司 | Data screening method and device for radius analysis original data and storage medium |
| CN117312726B (en) * | 2023-11-29 | 2024-02-06 | 中国船舶集团有限公司第七〇七研究所 | Capability assessment method during anchoring auxiliary power positioning operation |
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