CN116187058A - Liquid level telemetry method and liquid level telemetry system - Google Patents

Liquid level telemetry method and liquid level telemetry system Download PDF

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Publication number
CN116187058A
CN116187058A CN202310148157.8A CN202310148157A CN116187058A CN 116187058 A CN116187058 A CN 116187058A CN 202310148157 A CN202310148157 A CN 202310148157A CN 116187058 A CN116187058 A CN 116187058A
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draft
liquid
ship
pressure
data
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张亚
柳卫东
武姗
王璐玭
郑双燕
柳一点
李啸峰
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Jiangnan Shipyard Group Co Ltd
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Jiangnan Shipyard Group Co Ltd
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    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/20—Design optimisation, verification or simulation
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/10—Geometric CAD
    • G06F30/15—Vehicle, aircraft or watercraft design
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T17/00—Three dimensional [3D] modelling, e.g. data description of 3D objects
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation

Abstract

The invention discloses a liquid level telemetry method and a liquid level telemetry system. And calculating the draft distance of the ship according to the draft pressure data and the atmospheric pressure data of the ship, and calculating the trim and the heel of the ship according to the draft distance. And calculating the vertical distance from the liquid level in the liquid tank to the position where the liquid tank pressure data are acquired according to the liquid tank pressure data and the density of the liquid in the liquid tank. Creating an in-tank liquid level in the three-dimensional model of the ship according to the acquisition position, the vertical distance, the trim and the heel of the pressure data in the liquid tank; the liquid amount of the liquid in the cabin is calculated according to the three-dimensional model of the ship and the created liquid level in the cabin. According to the invention, the liquid volume in the liquid tank is calculated by using the three-dimensional model of the liquid tank, so that the accuracy of calculation is greatly improved.

Description

Liquid level telemetry method and liquid level telemetry system
Technical Field
The invention relates to the technical field of ship liquid level measurement, in particular to a liquid level telemetry method and a liquid level telemetry system.
Background
The bilge table is a comparison table among the data of the liquid level height, the liquid level volume, the sectional area of each horizontal plane and the like of one liquid tank. The prior art liquid level telemetry system calculation method generally relies on a bilge gauge to calculate the bilge, for example, the patent issued with the publication number CN108388737B for a method and system for calculating the liquid volume of a ship liquid tank uses the bilge gauge to calculate the volume of the actual liquid in the liquid tank.
However, the bilge gauge generally only represents bilge, sectional area, etc. in the depth direction, and the design difficulty and maintenance cost of a liquid level telemetry system depending on the bilge gauge are low, but the calculation accuracy is limited by the fineness of bilge gauge data and the complexity of the tank shape. As tank shapes become more complex, the accuracy of the restored volumes with complex three-dimensional shapes of pitch and roll will become worse by virtue of the two-dimensional bilge gauges.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a liquid level telemetry method and a liquid level telemetry system for improving accuracy of liquid level telemetry.
To achieve the above and other related objects, the present invention provides a liquid level telemetry method for calculating a liquid amount in a liquid tank of a ship, comprising:
creating a three-dimensional model of a tank in the ship;
acquiring ship draft pressure data, tank pressure data, atmospheric pressure data, density data of liquid in the tank and a tank pressure data acquisition position;
calculating the draft distance of the ship according to the draft pressure data and the atmospheric pressure data of the ship, and calculating the trim and the heel of the ship according to the draft distance;
calculating the vertical distance from the liquid level in the liquid tank to the position where the liquid tank pressure data are acquired according to the liquid tank pressure data and the density of the liquid in the liquid tank;
creating an in-tank liquid level in a three-dimensional model of the ship according to the acquisition position, the vertical distance, the trim and the heel of the pressure data in the liquid tank;
the liquid amount of the liquid in the cabin is calculated according to the three-dimensional model of the ship and the created liquid level in the cabin.
Optionally, the vessel draft data includes stem draft data, port midship draft data, starboard midship draft data, and stern draft data.
Optionally, in the step of acquiring the ship draft data, the method includes:
acquiring a ship dynamic pressure correction value and a ship draft pressure actual measurement value;
and calculating ship draft data according to the ship draft actual measurement value and the ship dynamic pressure correction value.
Optionally, the step of acquiring the dynamic pressure correction value of the ship includes:
acquiring a port internal pressure value of a historical ship in a draft state and a dynamic pressure value during offshore navigation, wherein the acquired port internal pressure value and dynamic pressure value during offshore navigation are acquired under the same loading condition;
and calculating the ship dynamic pressure correction value according to the harbor pressure value and the dynamic pressure value during offshore navigation.
Optionally, in the step of calculating the draft of the vessel from the vessel draft data, comprising:
according to formula D x ＝(P x +P y -P 0 )/RHO 0 Calculating and obtaining the ship draft distance Dx;
wherein Dx is the draft distance of the ship, and the draft distance Dx comprises the bow draft distance Df and the port midship draft distanceFrom Dmp, starboard midship draft distance Dms, stern draft distance Da; px is the actual measurement value of the draft pressure of the ship, and the actual measurement value P of the draft pressure of the ship X The method comprises a stem draft measured value Pdf, a port midship draft measured value Pdmp, a starboard midship draft measured value Pdms and a stern draft measured value Pda; py is a ship dynamic pressure correction value, wherein the ship dynamic pressure correction value Py comprises a ship bow dynamic pressure correction value Pf, a port midship dynamic pressure correction value Pmp, a starboard midship dynamic pressure correction value Pms and a ship stern dynamic pressure correction value Pa; p (P) 0 Is an atmospheric pressure value; RHO (RHO) 0 Is the density of the outboard seawater; g is gravitational acceleration.
Optionally, the step of calculating the vertical distance from the liquid level in the tank to the position where the liquid pressure data is collected according to the liquid pressure data and the density of the liquid in the tank comprises:
according to the formula h= (P-P 0 ) Calculating and obtaining the vertical distance from the liquid level in the liquid tank to the position where the data of the pressure in the liquid tank are collected;
wherein H is the vertical distance from the liquid level in the liquid tank to the position where the data of the pressure in the liquid tank are collected; p is the pressure value in the liquid cabin; p (P) 0 Is an atmospheric pressure value; RHO is the density of the liquid in the tank; g is gravitational acceleration.
Optionally, after the step of calculating the liquid amount of the liquid in the tank from the three-dimensional model of the ship and the created liquid level in the tank, further comprising:
acquiring ship draft pressure data and theoretical values of heel and toe according to the liquid amount in the liquid cabin;
comparing the measured values of the ship draft pressure data, the trim and the trim with theoretical values;
and determining whether to calibrate the actual state of the ship according to the comparison difference value.
Optionally, the step of calculating the draft distance of the vessel from the vessel draft pressure data, the atmospheric pressure data includes:
determining a stem draft position, a port midship draft pressure position, a starboard midship draft position and a stern draft position according to the stem draft distance, the port midship draft pressure distance, the starboard midship draft distance and the stern draft distance;
when the stem draft position, the port midship draft pressure position, the starboard midship draft position and the stern draft position are not on the same straight line, the stem draft distance, the port midship draft pressure distance, the starboard midship draft distance and the stern draft distance are corrected so that the stem draft position, the port midship draft position, the starboard midship draft position and the stern draft position are on the same straight line.
The invention also provides a liquid level telemetry system comprising:
the three-dimensional model creation module of the liquid tank is used for creating a three-dimensional model of the liquid tank;
the data acquisition module is used for acquiring ship draft pressure data, tank pressure data, atmospheric pressure data, a tank pressure data acquisition position and the density of liquid in the tank;
the liquid level telemetering calculation module is used for calculating the draft distance of the ship according to the draft pressure data and the atmospheric pressure data of the ship and calculating the trim and the heel of the ship according to the draft distance; calculating the vertical distance from the liquid level in the liquid tank to the position where the liquid tank pressure data are acquired according to the liquid tank pressure data and the density of the liquid in the liquid tank;
the in-cabin liquid level creating module is used for creating in-cabin liquid level in the three-dimensional model of the ship according to the acquisition position, the vertical distance, the trim and the heel of the pressure data in the liquid cabin;
and the liquid level calculating module is used for calculating the liquid amount of the liquid in the cabin according to the three-dimensional model of the liquid cabin and the liquid level in the cabin.
Optionally, the ship draft data is calculated according to the ship draft actual measurement value and the ship dynamic pressure correction value.
Alternatively, the dynamic pressure correction value of the ship is calculated based on the pressure value in the port of the ship and the dynamic pressure value at the time of marine navigation.
Optionally, the liquid level telemetry system further comprises:
the draft pressure sensor is arranged outside the ship;
the liquid cabin internal pressure sensor is arranged in each liquid cabin;
the atmospheric pressure sensor is arranged at the position where the ship contacts with the atmosphere;
the draft pressure sensor, the intra-tank pressure sensor and the atmospheric pressure sensor are all in signal connection with the data acquisition module.
Optionally, the draft pressure sensor includes a first draft pressure sensor disposed at the stem, a second draft pressure sensor disposed at the port midship, a third draft pressure sensor disposed at the starboard midship, and a fourth draft pressure sensor disposed at the stern.
Optionally, the liquid level telemetry system further comprises:
the ship data theoretical value calculation module is used for calculating theoretical values of ship draft pressure data, heel and toe according to the liquid amount in the liquid cabin;
and the data comparison judging module is used for comparing the actual measurement values of the ship draft pressure data, the trim and the trim with the theoretical values and judging whether to calibrate the actual state of the ship.
Optionally, the liquid level telemetry system further comprises:
the data input module is used for independently inputting the liquid density RHO in the liquid tank by a user, wherein the installation positions Pos (X, Y, Z) of all the pressure sensors are provided with a stem dynamic pressure correction value Pf, a port midship dynamic pressure correction value Pmp, a starboard midship dynamic pressure correction value Pms, a stern dynamic pressure correction value Pa and a liquid level height value H when the output pressure of the pressure sensor in the liquid tank is 0 0 And transmits the input data to the data acquisition module.
Compared with the prior art, the liquid level telemetry method and the liquid level telemetry system have the following beneficial effects:
the liquid level telemetering method comprises the steps of creating a three-dimensional model of a liquid tank in a ship, and acquiring ship draft pressure data, liquid tank pressure data, atmospheric pressure data, liquid density data in the liquid tank and liquid tank pressure data acquisition positions. And calculating the draft distance of the ship according to the draft pressure data and the atmospheric pressure data of the ship, and calculating the trim and the heel of the ship according to the draft distance. And calculating the vertical distance from the liquid level in the liquid tank to the position where the liquid tank pressure data are acquired according to the liquid tank pressure data and the density of the liquid in the liquid tank. Creating an in-tank liquid level in the three-dimensional model of the ship according to the acquisition position, the vertical distance, the trim and the heel of the pressure data in the liquid tank; the liquid amount of the liquid in the cabin is calculated according to the three-dimensional model of the ship and the created liquid level in the cabin. According to the invention, the liquid volume in the liquid tank is calculated by using the three-dimensional model of the liquid tank, so that the accuracy of calculation is greatly improved. In addition, the data input by the user in the invention comprises the liquid density RHO in the liquid tank, the installation positions Pos (X, Y, Z) of the pressure sensors, the pressure correction values Pf, pmp, pms and Pa of the stern and stern, and the liquid level height value H0 when the output pressure of the sensors is 0. The density of the liquid loaded by the ship is not always theoretical and fixed, so that a user is allowed to customize the density RHO of the liquid, and the accuracy of the calculated data such as the liquid level height and the liquid weight is improved. The sensor position given to the liquid level telemetry system is usually a theoretical position, and the sensor position is different from the actual installation position, so that the user is allowed to customize, and the calibration and the verification of the liquid level telemetry system are convenient.
Furthermore, the draft pressure data is corrected by adopting the dynamic pressure correction value, so that the calculation accuracy of the ship heel and trim values is improved, and the accuracy of the whole system is further improved.
Furthermore, the invention also comprises the steps of acquiring theoretical values of ship draft pressure data, trim and trim according to the liquid amount in the liquid cabin, comparing the theoretical values with the actual measured values, and calibrating the actual state of the ship according to the theoretical values.
Furthermore, the invention also comprises a step of correcting the draft data after the hull is deformed, and the accuracy of the calculated data is further improved.
The liquid level telemetry system is used for the liquid level telemetry method, and the technical effects can be achieved.
Drawings
FIG. 1 is a flow chart of a method of level telemetry in accordance with an embodiment of the present invention;
FIG. 2 is a schematic diagram illustrating the implementation of a fluid level telemetry method according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a fluid level telemetry system according to an embodiment of the invention.
Detailed Description
Further advantages and effects of the present invention will become apparent to those skilled in the art from the disclosure of the present invention, which is described by the following specific examples. The invention may be practiced or carried out in other embodiments and details within the scope and range of equivalents of the specific embodiments and ranges of equivalents, and modifications and variations may be made in the practice of the invention without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments may be combined with each other without conflict.
It should be noted that the illustrations provided in the embodiments of the invention are merely schematic illustrations of the basic concepts of the invention, and only the components related to the invention are shown in the illustrations, rather than being drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of each component in actual implementation may be arbitrarily changed, and the layout of the components may be more complicated. The structures, proportions, sizes, etc. shown in the drawings are shown only in connection with the present disclosure, and should not be construed as limiting the scope of the invention, since any modification, variation in proportions, or adjustment of the structures, proportions, etc. which would otherwise be used by those skilled in the art, should not be construed as limiting the scope of the invention, which is otherwise, used by the claims, without affecting the efficacy of the invention or the objects obtained.
The embodiment discloses a liquid level telemetry method, referring to fig. 1, the liquid level telemetry method includes the following steps:
s101: creating a three-dimensional model of a tank in the ship;
and carrying a full-cabin three-dimensional model, and defining the structural reduction coefficient of each tank. Generally consistent with the three-dimensional model and structural reduction coefficients used for stability calculations. Compared with a bilge table, the calculation accuracy of the complex liquid tank can be greatly provided by adopting a three-dimensional model.
S102: acquiring ship draft pressure data, tank pressure data, atmospheric pressure data, density data of liquid in the tank and a tank pressure data acquisition position;
referring to fig. 2, ship draft pressure data, tank pressure data, atmospheric pressure data, density data of liquid in the tank, and tank pressure data acquisition locations are acquired. The ship draft pressure data comprises bow draft pressure data, port midship draft pressure data, starboard midship draft pressure data and stern draft pressure data. The data can be obtained by arranging pressure sensors at corresponding positions of the ship, and the density data of the liquid in the liquid tank is customized according to actual conditions. The embodiment is provided with 4 draught pressure sensors outside the ship, and each draught pressure sensor comprises a first draught pressure sensor arranged at the bow, a second draught pressure sensor arranged at the port midship, a third draught pressure sensor arranged at the starboard midship and a fourth draught pressure sensor arranged at the stern. A tank pressure sensor is provided in each tank, and an atmospheric pressure sensor is provided at any position of the ship exposed to the atmosphere. And the sensor is in signal connection with the data acquisition module so as to acquire the data. The liquid tank pressure data acquisition position is the installation position Pos (X, Y, Z) of the liquid tank pressure sensor.
When the ship sails at a certain speed, dynamic pressure is formed in the upper part of the ship body under the influence of the speed, waves and suction of the propeller. When the draft sensor is positioned in the dynamic pressure area, the acquired pressure signal is equal to the dynamic pressure plus the static pressure. The dynamic pressure influence is not eliminated, the draft error can reach 30% or more, and the floating state of the ship is seriously distorted. Draft distortion will reduce the accuracy of vessel trim and trim, thereby affecting the calculated liquid level height H, volume and Weight of all tanks. Thus, distortion of the draft calculation may reduce the accuracy of the overall system. It is very necessary to perform dynamic pressure correction of draft.
The dynamic pressure correction value can be determined by two methods, namely numerical simulation, calculation of the dynamic pressure distribution of the ship body under the condition that the ship is usually under the draught by using a propeller, and extraction of the dynamic pressure value at the position of the draught sensor. The actual sea state is more complex and there may still be a difference between the analog and actual values. The dynamic pressure value during offshore navigation is reversely pushed by the pressure value in the port under the common eating water. The harbor level is calm, when the ship is berthed in the harbor, the ship speed is zero, the propeller is static, the dynamic pressure is 0 at the moment, and the static pressure is only collected by the draft sensor. And under the same loading working condition, the difference between the pressure value in the port and the offshore pressure value is the dynamic pressure correction value. The offshore pressure values suggest the selection of pressure values under common sea conditions, common draft, common power and propeller rotational speed. In the present embodiment, the second method is adopted to calculate the dynamic pressure correction value of the ship. That is, the dynamic pressure value at sea navigation is obtained under the same loading condition according to the port internal pressure value and dynamic pressure value at sea navigation of the historical ship in the draft state, and the ship dynamic pressure correction value is calculated according to the port internal pressure value and dynamic pressure value at sea navigation. The calculated ship dynamic pressure correction value can also be obtained through user definition.
It should be noted that the data input by the user includes the liquid density RHO in the tank, the installation position Pos (X, Y, Z) of each pressure sensor, the midship stern dynamic pressure correction value Pf, pmp, pms, pa, the liquid level height value H when the sensor output pressure is 0 0 。
S103: calculating the draft distance of the ship according to the draft pressure data and the atmospheric pressure data of the ship, and calculating the trim and the heel of the ship according to the draft distance;
referring to fig. 2, a stem/stern draft sensor receives a stem draft measured value Pdf, a port midship draft measured value Pdmp, a starboard midship draft measured value Pdms, a stern draft measured value Pda, and a pressure P acquired by an atmospheric pressure sensor 0 Receiving the density RHO of the outboard seawater 0 Receiving the positions Pos (X, Y, Z) of the draft pressure sensors, and calculating the draft distance D (the distance from the outer water surface to the bottom of the ship at the X position) at the positions of the bow and stern draft sensors. According to formula D x ＝(P x +P y -P 0 )/RHO 0 Per g, meterCalculating and obtaining a ship draft distance Dx; wherein Dx is the ship draft distance, which includes the stem draft distance Df, the port midship draft distance Dmp, the starboard midship draft distance Dms, and the stern draft distance Da; px is a measured ship draft, and the measured ship draft Px includes a measured stem draft Pdf, a measured port midship draft Pdmp, a measured starboard midship draft Pdms, and a measured stern draft Pda; py is a ship dynamic pressure correction value, wherein the ship dynamic pressure correction value Py comprises a ship bow dynamic pressure correction value Pf, a port midship dynamic pressure correction value Pmp, a starboard midship dynamic pressure correction value Pms and a ship stern dynamic pressure correction value Pa; p (P) 0 Is an atmospheric pressure value; RHO (RHO) 0 Is the density of the outboard seawater; g is gravitational acceleration. Taking draft Df at the stem draft sensor position as an example, D at the stem draft sensor position Pos (X, Y, Z) f ＝(P df +P f -P 0 )/RHO 0 /g。
The ship runs for a long time, the ship body can generate deformation, usually a midspan/midspan, after deformation, the draft D (midship draft taking the average value of port and starboard sides) at the position of the midship stern draft sensor is not on the same straight line, and in order to reduce the influence of the midspan/midspan, the midship stern draft needs to be corrected to the same straight line. The least square method is recommended to be used for correction, and the calculation method is the prior art and is not described herein. After correction, draft values at different positions along the ship length direction are on the same straight line, namely draft Df at the bow vertical line and draft Da at the stern vertical line can be calculated, and ship trim Tr is calculated. The vessel Heel was calculated using the mid-left and right draft Dmp and Dms.
When the signals acquired by the 4 draft sensors are received, 4 points are used for calculating the draft line, when 1 or 2 sensors fail, the remaining 3 or 2 points are used for calculating the numerical value of the other failed sensor, and then the draft line is calculated. This calculation logic can minimize the negative impact of the failure of the draft sensor.
S104: calculating the vertical distance from the liquid level in the liquid tank to the position where the liquid tank pressure data are acquired according to the liquid tank pressure data and the density of the liquid in the liquid tank;
referring to fig. 2, a receiving tankThe pressure P acquired by the inner sensor receives the density RHO of the liquid in the liquid cabin. Taking into account the position Pos (X, Y, Z) of the pressure sensor in the tank, calculating the vertical height h= (P-P) of the level distance sensor 0 )/RHO/g。
When the data of the pressure sensor in the liquid tank is P 0 When in use, the liquid level H below the installation height of the pressure sensor in the liquid cabin can be measured 0 Is set as user-defined H 0 The maximum height of (2) cannot exceed the installation height of the pressure sensor in the tank. In particular, when the pressure sensor is used to obtain pressure data in the tank, the pressure sensor has a data P because the pressure sensor has a certain installation height, i.e. the installation position of the pressure sensor is a certain distance from the bilge 0 In this case, there is a possibility that liquid may exist in the liquid chamber at a certain height, but the dead zone is below the pressure sensor, and cannot be detected by the pressure sensor. For tanks with large bottom areas, assuming a mounting height of 0.2m, the dead zone volume can reach approximately one hundred cubic meters, so the dead zone load needs to be specially prompted and carefully handled. The blind area is not detected, and is assumed to be empty, half-empty and half-full, and the full is inaccurate. In order to avoid this, the present embodiment provides that the liquid level H below the installation height of the pressure sensor can be set when the output pressure of the pressure sensor in the liquid tank is 0 0 Set to user-defined, but user-set H 0 The maximum height of (2) cannot exceed the installation height of the pressure sensor in the tank. If the tank is swept, i.e. it is determined that no liquid is present in the tank, H can be applied 0 Set to 0. Thus, if the pressure P acquired by the sensor in the tank is P 0 According to the received liquid level height value H below the user-defined sensor installation height 0 And creating an in-cabin page to calculate and prompting the user that the liquid level is lower than the sensor height.
S105: creating an in-tank liquid level in a three-dimensional model of the ship according to the acquisition position, the vertical distance, the trim and the heel of the pressure data in the liquid tank;
because the longitudinal inclination angle and the transverse inclination angle of the liquid level in the cabin are the same as those of the ship, the liquid level in the cabin can be established according to the data acquisition position of the pressure in the liquid cabin, the vertical height of the liquid level distance sensor and the longitudinal inclination angle and the transverse inclination angle of the liquid level in the cabin.
S106: the liquid amount of the liquid in the cabin is calculated according to the three-dimensional model of the ship and the created liquid level in the cabin.
Referring to fig. 2, the three-dimensional shape of the liquid in the cabin can be determined according to the carried three-dimensional model of the whole cabin and the calculated liquid level in the cabin, and the liquid Volume and the liquid level average height H can be calculated by considering the structural reduction coefficient. The three-dimensional object volume calculation method can be obtained by a calculation method which is common in the prior art, and is not described in detail here. Weight was calculated from the liquid density RHO.
In the present embodiment, the following steps are further included after step S106:
referring to fig. 2, the liquid level height H, the Volume, the Weight, the bow draft Df, the left and right midship draft Dmp/Dms, the stern draft Da, the trim Tr, the Heel, and the like of each tank are output to a display for display, and instantaneous values and time average values of each value are output and displayed. When the ship sails at sea, the instantaneous value fluctuates greatly, the time average value is more visual, and the ship floating state and the loading condition are truly reflected. The liquid level telemetering calculation module outputs the time average value of the loading capacity of each liquid tank to the loading computer for the loading computer to calculate the complete stability and the broken tank stability.
Receiving and displaying the theoretical midship stern draft, the heel and the trim output by the loading computer. The loading computer receives the liquid amount (loading amount) in the cabin obtained by liquid level telemetry calculation, and the gravity center distribution condition of the whole ship can be obtained according to the data, and the weight gravity center of the whole ship can also be obtained. And loading a three-dimensional model of the ship in the computer to obtain theoretical values of the draft, the heel and toe, the heel and the heel of the ship. The liquid level remote measuring method is to calculate the draft of the midship stern according to the actually measured pressure value, and obtain the measured value through heel and toe. And comparing the theoretical value with the actual measured value, and analyzing the accuracy of the liquid level telemetry system. If the liquid level remote sensing system is close to the liquid level remote sensing system, the accuracy of the whole liquid level remote sensing system is proved to be good, and if the gap is too large, risk prompt is carried out on the accuracy of the system. The system engineer can be arranged to calibrate according to the actual state of the ship.
The embodiment also provides a liquid level telemetry system, referring to fig. 3, which includes a data acquisition module, a tank three-dimensional model creation module, a liquid level telemetry calculation module, an in-tank liquid level creation module, and a liquid amount calculation module, where the data acquisition module is configured to acquire ship draft pressure data, tank pressure data, atmospheric pressure data, and a density of liquid in the tank. The tank three-dimensional model creation module is used for creating a three-dimensional model of the tank. The liquid level telemetering calculation module is used for calculating the draft distance of the ship according to the draft pressure data and the atmospheric pressure data of the ship and calculating the trim and the heel of the ship according to the draft distance; and calculating the vertical distance from the liquid level in the liquid tank to the position where the liquid tank pressure data are acquired according to the liquid tank pressure data and the density of the liquid in the liquid tank. The in-cabin liquid level creation module is used for creating an in-cabin liquid level in the three-dimensional model of the ship according to the vertical distance, the trim and the heel. The liquid amount calculating module is used for calculating the liquid amount of the liquid in the tank according to the three-dimensional model of the tank and the liquid level in the tank.
Optionally, the ship draft data is calculated according to the ship draft actual measurement value and the ship dynamic pressure correction value. The ship dynamic pressure correction value is obtained by calculating according to the pressure value in the ship historical port and the dynamic pressure value during offshore navigation.
Optionally, the liquid level telemetry system is further provided with 4 draught pressure sensors outside the ship, and each draught pressure sensor comprises a first draught pressure sensor arranged at the bow, a second draught pressure sensor arranged at the port midship, a third draught pressure sensor arranged at the starboard midship and a fourth draught pressure sensor arranged at the stern. Each tank is internally provided with a tank internal pressure sensor, and any position of the ship exposed to the atmosphere is provided with an atmospheric pressure sensor. The draft pressure sensor, the intra-tank pressure sensor and the atmospheric pressure sensor are all in signal connection with the data acquisition module.
Optionally, referring to fig. 3, the liquid level telemetry system further includes a ship data theoretical value calculation module and a data comparison judgment module, where the ship data theoretical value calculation module is configured to calculate theoretical values of ship draft pressure data, trim and trim according to the liquid amount in the liquid tank; the data comparison judging module is used for comparing the actual measurement values of the ship draft pressure data, the trim and the trim with the theoretical values and judging whether to calibrate the actual values or the actual states of the ship.
Optionally, referring to fig. 3, the level telemetry system further includes a data input module for a user to manually input data and transmit the input data to the value data acquisition module. The data for user-defined input include the liquid density RHO in the tank, the mounting positions Pos (X, Y, Z) of the pressure sensors, the pressure correction values Pf, pmp, pms, pa of the stern and stern, the liquid level height H when the sensor output pressure is 0 0 . The density of the liquid loaded by the ship is not always theoretical and fixed, so that a user is allowed to customize the density RHO of the liquid, and the accuracy of the calculated data such as the liquid level height and the liquid weight is improved. The sensor position given to the liquid level telemetry system is usually a theoretical position, and the sensor position is different from the actual installation position, so that the user is allowed to customize, and the calibration and the verification of the liquid level telemetry system are convenient.
The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims (15)

1. A method of level telemetry for calculating an amount of liquid in a tank of a vessel, comprising:
creating a three-dimensional model of a tank in the ship;
acquiring ship draft pressure data, tank pressure data, atmospheric pressure data, density data of liquid in the tank and a tank pressure data acquisition position;
calculating the draft distance of the ship according to the draft pressure data and the atmospheric pressure data of the ship, and calculating the trim and the heel of the ship according to the draft distance;
calculating the vertical distance from the liquid level in the liquid tank to the position where the liquid tank pressure data are acquired according to the liquid tank pressure data and the density of the liquid in the liquid tank;
creating an in-tank liquid level in the three-dimensional model of the ship according to the acquisition position, the vertical distance, the trim and the heel of the pressure data in the liquid tank;
the liquid amount of the liquid in the cabin is calculated according to the three-dimensional model of the ship and the created liquid level in the cabin.
2. The method of level telemetry of claim 1, wherein the vessel draft pressure data comprises stem draft pressure data, port midship draft pressure data, starboard midship draft pressure data, and stern draft pressure data.
3. The method of level telemetry according to claim 1, wherein in the step of obtaining vessel draft data, comprising:
acquiring a ship dynamic pressure correction value and a ship draft pressure actual measurement value;
and calculating ship draft data according to the ship draft actual measurement value and the ship dynamic pressure correction value.
4. A liquid level telemetry method as claimed in claim 3 wherein, in the step of obtaining the hydrodynamic correction value of the vessel, it comprises:
acquiring a port internal pressure value of a historical ship in a draft state and a dynamic pressure value during offshore navigation, wherein the acquired port internal pressure value and dynamic pressure value during offshore navigation are acquired under the same loading condition;
and calculating a ship dynamic pressure correction value according to the harbor pressure value and the dynamic pressure value during offshore navigation.
5. A method of level telemetry as claimed in claim 3 wherein, in the step of calculating the draft of the vessel from the vessel draft data, comprising:
according to formula D x ＝(P x +P y -P 0 )/RHO 0 Calculating and obtaining the ship draft distance Dx;
wherein Dx is the ship draft distance, which includes the stem draft distance Df, the port midship draft distance Dmp, the starboard midship draft distance Dms, and the stern draft distance Da; px is the actual measurement value of the draft pressure of the ship, and the actual measurement value P of the draft pressure of the ship X The method comprises a stem draft measured value Pdf, a port midship draft measured value Pdmp, a starboard midship draft measured value Pdms and a stern draft measured value Pda; py is a ship dynamic pressure correction value, wherein the ship dynamic pressure correction value Py comprises a ship bow dynamic pressure correction value Pf, a port midship dynamic pressure correction value Pmp, a starboard midship dynamic pressure correction value Pms and a ship stern dynamic pressure correction value Pa; p (P) 0 Is an atmospheric pressure value; RHO (RHO) 0 Is the density of the outboard seawater; g is gravitational acceleration.
6. A method of telemetry of liquid level as claimed in claim 3 wherein the step of calculating the vertical distance of the liquid level in the tank from the data of the pressure in the tank and the density of the liquid in the tank comprises:
according to the formula h= (P-P 0 ) Calculating and obtaining the vertical distance from the liquid level in the liquid tank to the position where the data of the pressure in the liquid tank are collected;
wherein H is the vertical distance from the liquid level in the liquid tank to the position where the data of the pressure in the liquid tank are collected; p is the pressure value in the liquid cabin; p (P) 0 Is an atmospheric pressure value; RHO is the density of the liquid in the tank; g is gravitational acceleration.
7. A liquid level telemetry method as claimed in claim 3, further comprising, after the step of calculating the liquid volume of the liquid in the tank from the three-dimensional model of the vessel and the created liquid level in the tank:
acquiring ship draft pressure data and theoretical values of heel and toe according to the liquid amount in the liquid cabin;
comparing the measured values of the ship draft pressure data, the trim and the trim with theoretical values;
and determining whether to calibrate the actual state of the ship according to the comparison difference value.
8. A liquid level telemetry method as claimed in claim 3 wherein, in the step of calculating the draft of the vessel from the vessel draft data, atmospheric pressure data, comprising:
determining a stem draft position, a port midship draft pressure position, a starboard midship draft position and a stern draft position according to the stem draft distance, the port midship draft pressure distance, the starboard midship draft distance and the stern draft distance;
when the stem draft position, the port midship draft pressure position, the starboard midship draft position and the stern draft position are not on the same straight line, the stem draft distance, the port midship draft pressure distance, the starboard midship draft distance and the stern draft distance are corrected so that the stem draft position, the port midship draft position, the starboard midship draft position and the stern draft position are on the same straight line.
9. A fluid level telemetry system, comprising:
the three-dimensional model creation module of the liquid tank is used for creating a three-dimensional model of the liquid tank;
the data acquisition module is used for acquiring ship draft pressure data, tank pressure data, atmospheric pressure data, a tank pressure data acquisition position and the density of liquid in the tank;
the liquid level telemetering calculation module is used for calculating the draft distance of the ship according to the draft pressure data and the atmospheric pressure data of the ship and calculating the trim and the heel of the ship according to the draft distance; calculating the vertical distance from the liquid level in the liquid tank to the position where the liquid tank pressure data are acquired according to the liquid tank pressure data and the density of the liquid in the liquid tank;
the in-cabin liquid level creating module is used for creating in-cabin liquid level in the three-dimensional model of the ship according to the acquisition position, the vertical distance, the trim and the heel of the pressure data in the liquid cabin;
and the liquid level calculating module is used for calculating the liquid amount of the liquid in the cabin according to the three-dimensional model of the liquid cabin and the liquid level in the cabin.
10. The fluid level telemetry system of claim 9 wherein the vessel draft data is calculated from a measured vessel draft and a dynamic pressure correction value.
11. The fluid level telemetry system of claim 10 wherein the hydrodynamic pressure correction value is calculated from historical port pressure values of the vessel and hydrodynamic pressure values during marine navigation.
12. The fluid level telemetry system of claim 9, further comprising:
the draft pressure sensor is arranged outside the ship;
the liquid cabin internal pressure sensor is arranged in each liquid cabin;
the atmospheric pressure sensor is arranged at the position where the ship contacts with the atmosphere;
the draft pressure sensor, the intra-tank pressure sensor and the atmospheric pressure sensor are all in signal connection with the data acquisition module.
13. The level telemetry system of claim 12, wherein the draft pressure sensor comprises a first draft pressure sensor disposed at a bow, a second draft pressure sensor disposed at a port midship, a third draft pressure sensor disposed at a starboard midship, and a fourth draft pressure sensor disposed at a stern.
14. The fluid level telemetry system of claim 9, further comprising:
the ship data theoretical value calculation module is used for calculating theoretical values of ship draft pressure data, heel and toe according to the liquid amount in the liquid cabin;
and the data comparison judging module is used for comparing the actual measurement values of the ship draft pressure data, the trim and the trim with the theoretical values and judging whether to calibrate the actual state of the ship.
15. The fluid level telemetry system of claim 13, further comprising:
the data input module is used for independently inputting the liquid density RHO in the liquid tank by a user, wherein the installation positions Pos (X, Y, Z) of all the pressure sensors are provided with a stem dynamic pressure correction value Pf, a port midship dynamic pressure correction value Pmp, a starboard midship dynamic pressure correction value Pms, a stern dynamic pressure correction value Pa and a liquid level height value H when the output pressure of the pressure sensor in the liquid tank is 0 0 And transmitting the input data to the data acquisition module.
CN202310148157.8A 2023-02-21 2023-02-21 Liquid level telemetry method and liquid level telemetry system Pending CN116187058A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310148157.8A CN116187058A (en) 2023-02-21 2023-02-21 Liquid level telemetry method and liquid level telemetry system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310148157.8A CN116187058A (en) 2023-02-21 2023-02-21 Liquid level telemetry method and liquid level telemetry system

Publications (1)

Publication Number Publication Date
CN116187058A true CN116187058A (en) 2023-05-30

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