Calculation method, device, equipment and storage medium for ship shafting transmission efficiency

Abstract

The present invention discloses a method, device, equipment and storage medium for calculating the transmission efficiency of a ship shaft system, wherein the ship comprises an engine, a transmission shaft and a propeller, wherein the output shaft of the engine drives the transmission shaft to rotate, and the transmission shaft drives the propeller to rotate, and the transmission shaft is provided with N bearings, wherein the number N is greater than or equal to 1, and comprises: determining the support reaction force of each bearing; and determining the transmission efficiency of the ship shaft system according to the support reaction force of each bearing. The technical solution provided by the embodiment of the present invention improves the transmission efficiency of the ship shaft system and the degree of fit of the corresponding ship.

Description

Technical Field

[0001] The present invention relates to the field of ship technology, and in particular to a method, device, equipment and storage medium for calculating the transmission efficiency of a ship shaft system. Background Art

[0002] Currently, there is no complete and practical calculation method for the specific values ​​of shaft transmission efficiency for a certain type of ship or even a specific ship in the industry. Designers can only make assessments based on reference values ​​given in some manuals or the International Maritime Organization (IMO).

[0003] For example, in the 2007 edition of the Practical Manual of Ship Design published by China Communications Science and Technology Press, it can be found that the estimated value of the shafting transmission efficiency of the stern engine room is 0.97-0.98; the estimated value of the shafting transmission efficiency of the white alloy stern tube bearing is 0.99; the estimated value of the shafting transmission efficiency of the intermediate sliding bearing is 0.986. For another example, in the MEPC.1 / Circ.850 guidelines issued by the IMO Environment Committee: the estimated value of the shafting transmission efficiency of the stern engine room is 0.98; the estimated value of the shafting transmission efficiency of the midship engine room is 0.97. The estimated value of the shafting transmission efficiency of the stern engine room given by the shafting manufacturer is 0.99, which is generally used in speed correction.

[0004] The above are reference values ​​given in various materials. The sources are unclear and there are many contradictory and inconsistent values. Users can only select values ​​according to their needs and applicable requirements. It is obviously unreasonable to use a fixed value without distinction for different ship types, different line arrangements, different propeller designs, and different power points.

[0005] In the process of ship design, the amount of shaft transmission efficiency used will affect the selection of the main engine installed power and power optimization point. In addition, in the process of verifying the rules and regulations, the values ​​taken by the International Maritime Organization or classification societies tend to be conservative, resulting in large equipment selection and increased construction costs. It even leads to the acquisition of EEDI certification. For example, for the 300,000-ton VLCC project of this ship, the installed power needs to be as small as possible to meet the carbon emission requirements; but at this power, the certification of the minimum propulsion power in severe sea conditions is on the critical edge of satisfaction. Therefore, whether the shaft transmission efficiency is 0.98 as required by regulations or 0.99 as recommended by the manufacturer has a fundamental impact on the certification.

[0006] Therefore, there is an urgent need for a calculation method for the ship shafting transmission efficiency to improve the ship shafting transmission efficiency and the degree of fit with the corresponding ship. Summary of the invention

[0007] The present invention provides a method, device, equipment and storage medium for calculating the transmission efficiency of a ship shaft system, so as to improve the transmission efficiency of the ship shaft system and the degree of fit with the corresponding ship.

[0008] According to one aspect of the present invention, a method for calculating the transmission efficiency of a ship shaft system is provided, wherein the ship comprises an engine, a transmission shaft and a propeller, wherein the output shaft of the engine drives the transmission shaft to rotate, and the transmission shaft drives the propeller to rotate, and the transmission shaft is provided with N bearings, wherein the number N is greater than or equal to 1, and the method comprises:

[0009] determining a support reaction force of each of the bearings;

[0010] The shafting transmission efficiency of the ship is determined according to the support reaction force of each bearing.

[0011] Optionally, determining the shafting transmission efficiency of the ship according to the support reaction force of the bearing includes:

[0012] The shafting transmission efficiency of the ship satisfies the following relationship:

[0013]

[0014] Among them, η s is the shafting transmission efficiency of the ship, F i is the reaction force of the ith bearing, μ i is the friction coefficient at the i-th bearing, r i is the radius of the transmission shaft at the i-th bearing, ω is the angular velocity of the transmission shaft, and Ps is the output power of the engine.

[0015] Optionally, determining the support reaction force of each of the bearings includes:

[0016] Determining the resultant force of the propeller acting in the radial direction of the transmission shaft;

[0017] Determining the bending moment of the transmission shaft in the longitudinal and radial directions;

[0018] Determining the bending moment of the transmission shaft in the transverse radial direction;

[0019] The support reaction force of each bearing is determined according to the resultant force of the propeller acting in the radial direction of the transmission shaft, the bending moment of the transmission shaft in the longitudinal radial direction and the bending moment of the transmission shaft in the transverse radial direction.

[0020] Optionally, determining the resultant force of the propeller acting in the radial direction of the transmission shaft includes:

[0021] Obtaining an average value of the transverse and radial forces of the propeller acting on the transmission shaft during at least two rotation cycles of the propeller;

[0022] Obtaining an average value of the longitudinal and radial forces of the propeller acting on the transmission shaft during at least two rotation cycles of the propeller;

[0023] The resultant force of the propeller in the radial direction acting on the transmission shaft is determined based on an average value of the transverse radial force of the propeller acting on the transmission shaft in at least two rotation cycles of the propeller and an average value of the longitudinal radial force of the propeller acting on the transmission shaft in at least two rotation cycles of the propeller.

[0024] Optionally, determining the bending moment of the transmission shaft at each bearing in the longitudinal radial direction includes:

[0025] determining an axial force exerted by the propeller on the transmission shaft;

[0026] Obtaining an average value of the displacement of the transmission shaft in the transverse radial direction during at least two rotation cycles of the propeller;

[0027] The bending moment of the transmission shaft in the longitudinal radial direction is determined according to the product of the axial force of the propeller acting on the transmission shaft and the average displacement of the axis center of the transmission shaft in the transverse radial direction within at least two rotation cycles of the propeller.

[0028] Optionally, determining the bending moment of the transmission shaft at each bearing in the transverse radial direction includes:

[0029] determining an axial force exerted by the propeller on the transmission shaft;

[0030] Obtaining an average value of the displacement of the axis of the transmission shaft in the longitudinal radial direction during at least two rotation cycles of the propeller;

[0031] The bending moment of the transmission shaft in the transverse radial direction is determined according to the product of the axial force of the propeller acting on the transmission shaft and the average displacement of the axis center of the transmission shaft in the longitudinal radial direction within at least two rotation cycles of the propeller.

[0032] Optionally, determining the axial force of the propeller acting on the transmission shaft includes:

[0033] Obtaining a maximum value and a minimum value of an axial force exerted by the propeller on the transmission shaft in at least two rotation cycles of the propeller;

[0034] The average value of the maximum value and the minimum value of the axial force exerted by the propeller on the transmission shaft in at least two rotation cycles of the propeller is taken as the axial force exerted by the propeller on the transmission shaft.

[0035] According to another aspect of the present invention, a device for calculating the transmission efficiency of a ship shaft system is provided, wherein the ship comprises an engine, a transmission shaft and a propeller, wherein the output shaft of the engine drives the transmission shaft to rotate, and the transmission shaft drives the propeller to rotate, and the transmission shaft is provided with N bearings, wherein the number N is greater than or equal to 1, and comprises:

[0036] A support reaction force determination module, the support reaction force determination module is used to determine the support reaction force of each of the bearings;

[0037] A module for determining the shafting transmission efficiency of a ship, wherein the module for determining the shafting transmission efficiency of the ship is used to determine the shafting transmission efficiency of the ship according to the support reaction force of each bearing.

[0038] According to another aspect of the present invention, there is provided a device for calculating the transmission efficiency of a ship shaft system, comprising:

[0039] at least one processor; and

[0040] a memory communicatively connected to the at least one processor; wherein,

[0041] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for calculating the ship shafting transmission efficiency described in any embodiment of the present invention.

[0042] According to another aspect of the present invention, a computer instruction is provided, wherein the computer instruction is used to implement the method for calculating the ship shafting transmission efficiency described in any embodiment of the present invention when executed by a processor.

[0043] The technical scheme provided by the embodiment of the present invention provides designers with a calculation method for determining the shafting transmission efficiency of a ship based on the support reaction force of each bearing in a specific ship. Compared with the method in which designers can only evaluate the shafting transmission efficiency of a ship based on some manuals or reference values ​​given by the International Maritime Organization (IMO), this method can make a specific analysis of different ships and different propeller operating conditions, and give the corresponding transmission efficiency, which is more in line with reality, and improves the accuracy of the ship shafting transmission efficiency obtained by the designer and the degree of fit between the ship shafting transmission efficiency and the corresponding ship. And compared with the traditional empirical value, this method starts with the force analysis of the shafting, derives and calculates the shafting transmission efficiency, and is easier to be recognized. Traditional empirical values ​​tend to be conservative, and the use of this method can derive a more accurate transmission efficiency, optimize the choice of engine power, and more accurately grasp the design point of the propeller, thereby obtaining a higher propulsion efficiency.

[0044] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 It is a flow chart of a method for calculating the transmission efficiency of a ship shaft system provided according to the first embodiment of the present invention;

[0047] Figure 2 This is a structural schematic diagram of a shafting transmission structure of a ship provided according to Embodiment 1 of the present invention;

[0048] Figure 3 for Figure 2 The mechanical simulation diagram of the shafting transmission structure of the ship is shown;

[0049] Figure 4 is a flow chart of a method for calculating the transmission efficiency of a ship shaft system provided according to the second embodiment of the present invention;

[0050] Figure 5 yes Figure 4 A schematic diagram of the process included in S210;

[0051] Figure 6 yes Figure 4 A schematic diagram of the process included in S220;

[0052] Figure 7 yes Figure 4 A schematic diagram of the process included in S230;

[0053] Figure 8 is a curve of the change of the blade rotation angle and the magnitude of the radial resultant force acting on the rotating shaft by the propeller provided in the second embodiment of the present invention;

[0054] Fig. 9 is a curve of the change of the blade rotation angle and the angle of the radial resultant force acting on the rotating shaft by the propeller provided in the second embodiment of the present invention;

[0055] Fig.10 A variation curve of a blade rotation angle and a longitudinal radial bending moment on a rotating shaft provided according to a second embodiment of the present invention;

[0056] Fig.11 A variation curve of a blade rotation angle and a bending moment in a transverse radial direction on a rotating shaft provided in accordance with a second embodiment of the present invention;

[0057] Fig.12 is a schematic diagram of the structure of a device for calculating the transmission efficiency of a ship shaft system provided according to a third embodiment of the present invention;

[0058] Fig.13 It is a structural schematic diagram of an electronic device for a method for calculating the transmission efficiency of a ship shaft system provided in a fourth embodiment of the present invention. DETAILED DESCRIPTION

[0059] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0060] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0061] Embodiment 1

[0062] Figure 1 1 is a flow chart of a method for calculating the shafting transmission efficiency of a ship provided according to the first embodiment of the present invention. This embodiment can be used for calculating the shafting transmission efficiency of a 300,000-ton VLCC ship at maximum continuous output power. The method can be executed by a calculation device for the shafting transmission efficiency of a ship, which can be implemented in the form of hardware and / or software, and can be configured in a calculation device for the shafting transmission efficiency of a ship. Figure 1 As shown, the method includes:

[0063] S110. Determine the support reaction force of each bearing.

[0064] Figure 2 It is a structural schematic diagram of a shafting transmission structure of a ship provided according to Embodiment 1 of the present invention. Figure 3 for Figure 2 The mechanical simulation diagram of the ship's shaft transmission structure is shown. The three-dimensional beam system software can be used to obtain Figure 3 The mechanical simulation diagram of the shaft transmission structure of the ship is shown. Figure 2 The shaft transmission structure of the ship includes an engine 100, a transmission shaft 200 and a propeller 300. The output shaft of the engine 100 drives the transmission shaft 200 to rotate, and the transmission shaft 200 drives the propeller 300 to rotate. The transmission shaft 200 is provided with N bearings, and the number N is greater than or equal to 1. Exemplary, Figure 2 3 bearings are shown in FIG. 4 , which are the intermediate shaft bearing 401, the stern tube front bearing 402 and the stern tube rear bearing 403. Since the stern tube rear bearing 403 is relatively long, Figure 3 In the mechanical simulation diagram of the shaft transmission structure of the ship shown, the support reaction force of the stern tube rear bearing 403 is simulated by the support reaction force Fc received by node C and the support reaction force Fd received by node D. The support reaction force of the stern tube front bearing 402 is simulated by the support reaction force Fb received by node B. The support reaction force of the intermediate shaft bearing 401 is simulated by the support reaction force Fa received by node A.

[0065] It should be noted that the axial force Fx of the propeller 300 on the transmission shaft 200 and the radial force of the propeller 300 on the transmission shaft 200 cause each bearing to have a corresponding support reaction force.

[0066] It should be pointed out that in order to balance the loads of the bearings, the bearings (including the bearings in the engine 100) are not actually installed on the same horizontal line, and have different degrees of vertical offset compared to the theoretical axis height. The vertical stiffness of the bearings is 5.0x10 6 N / mm, intermediate shaft bearing 401 takes 1.0x10 6 N / mm.

[0067] S120. Determine the shafting transmission efficiency of the ship according to the support reaction force of each bearing.

[0068] Optionally, S120 determines the shafting transmission efficiency of the ship based on the bearing reaction force including:

[0069] The shafting transmission efficiency of a ship satisfies the following relationship:

[0070]

[0071] Among them, η s is the shafting transmission efficiency of the ship, F iis the reaction force of the ith bearing, μ i is the friction coefficient at the i-th bearing, r i is the radius of the transmission shaft at the i-th bearing, ω is the angular velocity of the transmission shaft, and Ps is the output power of the engine.

[0072] For example, Figure 2 The shafting transmission structure of the ship shown Figure 3 The mechanical simulation diagram of the shafting transmission structure of the ship is shown. The shafting transmission efficiency of the ship satisfies the following relationship:

[0073]

[0074] Among them, η s is the shafting transmission efficiency of the ship, F a is the support reaction force of the intermediate shaft bearing 401, μ a is the friction coefficient of the intermediate shaft bearing 401, r a F is the radius of the transmission shaft of the intermediate shaft bearing 401; b is the support reaction force of the stern tube front bearing 402, μ b is the friction coefficient of the stern tube front bearing 402, r b F is the radius of the transmission shaft of the stern tube front bearing 402; c is the support reaction force at the node C of the rear bearing 403 of the stern tube, μ c is the friction coefficient at the node C of the stern tube rear bearing 403, r c F is the radius of the transmission shaft at the node C of the rear bearing 403 of the stern tube; d is the support reaction force at the node D of the rear bearing 403 of the stern tube, μ d is the friction coefficient at the node D of the stern tube rear bearing 403, r d is the radius of the transmission shaft at the node D of the stern tube rear bearing 403, ω is the angular velocity of the transmission shaft 200. Ps is the output power of the engine 100.

[0075] From the table of friction coefficients of various bearings, it can be seen that the radius of the transmission shaft 200 at each bearing and the angular velocity of the transmission shaft 200 are known data. Therefore, when the support reaction force of each bearing is determined, the shafting transmission efficiency of the ship can be accurately calculated.

[0076] The technical scheme provided by the embodiment of the present invention provides designers with a calculation method for determining the shafting transmission efficiency of a ship based on the support reaction force of each bearing in a specific ship. Compared with the method in which designers can only evaluate the shafting transmission efficiency of a ship based on some manuals or reference values ​​given by the International Maritime Organization (IMO), this method can make a specific analysis of different ships and different propeller operating conditions, and give the corresponding transmission efficiency, which is more in line with reality, and improves the accuracy of the ship shafting transmission efficiency obtained by the designer and the degree of fit between the ship shafting transmission efficiency and the corresponding ship. And compared with the traditional empirical value, this method starts with the force analysis of the shafting, derives and calculates the shafting transmission efficiency, and is easier to be recognized. Traditional empirical values ​​tend to be conservative, and the use of this method can derive a more accurate transmission efficiency, optimize the choice of engine power, and more accurately grasp the design point of the propeller, thereby obtaining a higher propulsion efficiency.

[0077] Embodiment 2

[0078] Figure 4 FIG. 1 is a flow chart of a method for calculating the transmission efficiency of a ship shaft system according to Embodiment 2 of the present invention. Figure 4 , the calculation method of the ship shaft transmission efficiency includes:

[0079] S210. Determine the resultant force of the propeller acting on the transmission shaft in the radial direction.

[0080] See also Figure 3 The radial direction can be decomposed into the longitudinal radial Z direction and the transverse radial Y direction. The resultant force of the propeller 300 on the transmission shaft 200 in the radial direction is the resultant force Fyz of the longitudinal radial force Fz and the transverse radial force Fy of the propeller 300 on the transmission shaft 200.

[0081] S220. Determine the bending moment of the transmission shaft in the longitudinal radial direction.

[0082] In this embodiment, the axial force Fx exerted by the propeller 300 on the transmission shaft 200 will cause the axis of the transmission shaft to be displaced in the transverse radial direction. This bending moment is the bending moment Mz of the transmission shaft 200 in the longitudinal radial direction.

[0083] S230. Determine the bending moment of the transmission shaft in the transverse radial direction.

[0084] In this embodiment, the axial force Fx exerted by the propeller 300 on the transmission shaft 200 may cause the axis of the transmission shaft 200 to be displaced in the longitudinal radial direction. This bending moment is the bending moment My of the transmission shaft 200 in the transverse radial direction.

[0085] S240. Determine the support reaction force of each bearing according to the resultant force of the propeller acting on the transmission shaft in the radial direction, the bending moment of the transmission shaft in the longitudinal radial direction, and the bending moment of the transmission shaft in the transverse radial direction.

[0086] For example, Figure 2 In the shafting transmission structure of the ship, according to the resultant force of the propeller 300 on the transmission shaft 200 in the radial direction, which is the resultant force Fyz of the longitudinal radial force Fz and the transverse radial force Fy of the propeller 300 on the transmission shaft 200, the bending moment Mz of the transmission shaft 200 in the longitudinal radial direction, and the bending moment My of the transmission shaft 200 in the transverse radial direction, the support reaction force Fa of the intermediate shaft bearing 401, the support reaction force Fb of the stern tube front bearing 402, the support reaction force Fc at the node C of the stern tube rear bearing 403, and the support reaction force Fd at the node D.

[0087] S250. Determine the shafting transmission efficiency of the ship according to the support reaction force of each bearing.

[0088] The implementation manner and beneficial effects of S250 may refer to the implementation manner and beneficial effects of S120.

[0089] On the basis of the above embodiments, the embodiments of the present invention further define the specific steps for determining the support reaction force of each bearing, namely, determining the support reaction force of each bearing according to the resultant force of the propeller acting on the transmission shaft in the radial direction, the bending moment of the transmission shaft in the longitudinal radial direction and the bending moment of the transmission shaft in the transverse radial direction, and then determining the shafting transmission efficiency of the ship according to the support reaction force of each bearing, thereby improving the shafting transmission efficiency of the ship and the degree of fit with the corresponding ship.

[0090] Figure 5 yes Figure 4 In S210, the flow chart includes: Figure 5 S210 determines that the resultant force of the propeller acting on the transmission shaft in the radial direction includes:

[0091] S2101. Obtain an average value of the transverse and radial forces of the propeller acting on the transmission shaft in at least two rotation cycles of the propeller.

[0092] S2102. Obtain an average value of the longitudinal and radial forces of the propeller acting on the transmission shaft in at least two rotation cycles of the propeller.

[0093] S2103. Determine the resultant force acting on the transmission shaft in the radial direction of the propeller according to an average value of the lateral radial force acting on the transmission shaft by the propeller in at least two rotation cycles of the propeller and an average value of the longitudinal radial force acting on the transmission shaft by the propeller in at least two rotation cycles of the propeller.

[0094] For example, see Figure 8 and Fig. 9The blade of the propeller 300 rotates at about 100 degrees per cycle. In each rotation cycle, the resultant force Fyz of the propeller 300 on the transmission shaft 200 in the radial direction increases first, reaches a maximum value, and then decreases. The angle of the resultant force Fyz of the propeller 300 on the transmission shaft 200 in the radial direction increases first, reaches a maximum value, and then decreases.

[0095] Therefore, on the basis of the above technical scheme, the resultant force of the propeller acting on the transmission shaft in the radial direction is determined according to the average value of the lateral radial force of the propeller acting on the transmission shaft in at least two rotation cycles of the propeller and the average value of the longitudinal radial force of the propeller acting on the transmission shaft in at least two rotation cycles of the propeller. This can improve the accuracy of the resultant force of the propeller acting in the radial direction of the transmission shaft, thereby improving the accuracy of the support reaction force of each bearing and the accuracy of the shafting transmission efficiency of the ship, thereby improving the ship shafting transmission efficiency and the degree of fit with the corresponding ship.

[0096] Figure 6 yes Figure 4 Schematic diagram of the process included in S220. Figure 6 , S220 determines the bending moment of the transmission shaft in the longitudinal and radial directions including:

[0097] S2201. Determine the axial force of the propeller on the transmission shaft.

[0098] Optionally, S2201 determines that the axial force of the propeller acting on the transmission shaft includes:

[0099] S2201a, obtaining the maximum and minimum values ​​of the axial force of the propeller acting on the transmission shaft in at least two rotation cycles of the propeller;

[0100] S2201b. Take the average value of the maximum value and the minimum value of the axial force of the propeller acting on the transmission shaft in at least two rotation cycles of the propeller as the axial force of the propeller acting on the transmission shaft.

[0101] Exemplarily, in each rotation cycle, the axial force Fx of the propeller 300 on the transmission shaft 200 increases first, reaches a maximum value, and then decreases. The angle of the axial force Fx of the propeller 300 on the transmission shaft 200 increases first, reaches a maximum value, and then decreases. Therefore, it is necessary to determine the axial force of the propeller on the transmission shaft based on the average value of the maximum value and the minimum value of the axial force of the propeller on the transmission shaft in at least two rotation cycles of the propeller, thereby improving the accuracy of the axial force of the propeller on the transmission shaft.

[0102] S2202. Obtain an average value of the displacement of the axis center of the transmission shaft in the transverse radial direction within at least two rotation cycles of the propeller.

[0103] Exemplarily, in each rotation cycle, under the action of the axial force Fx exerted by the propeller 300 on the transmission shaft 200, the displacement Y of the axis of the transmission shaft 200 in the transverse radial direction will change periodically. Specifically, the bending moment of the transmission shaft in the longitudinal radial direction at each bearing can be calculated by taking the average value of the maximum value and the minimum value of the displacement Y of the axis of the transmission shaft in the transverse radial direction in at least two rotation cycles of the propeller, thereby improving the accuracy of the bending moment of the transmission shaft in the longitudinal radial direction, thereby improving the transmission efficiency of the ship shaft system and the degree of fit of the corresponding ship.

[0104] S2203. Determine the bending moment of the transmission shaft in the longitudinal radial direction according to the product of the axial force of the propeller acting on the transmission shaft and the average value of the displacement of the axis of the transmission shaft in the transverse radial direction within at least two rotation cycles of the propeller.

[0105] On the basis of the above technical solution, the embodiment of the present invention further defines a method for calculating the bending moment of the transmission shaft in the longitudinal and radial directions. Fig.10 In each rotation cycle, under the action of the axial force Fx exerted by the propeller 300 on the transmission shaft 200, the bending moment Mz of the transmission shaft 200 in the longitudinal radial direction will change periodically. Therefore, the bending moment of the transmission shaft in the longitudinal radial direction is calculated by taking the average value of the maximum value and the minimum value of the displacement of the axis of the transmission shaft in the transverse radial direction in at least two rotation cycles of the propeller, thereby improving the accuracy of the bending moment of the transmission shaft in the longitudinal radial direction, thereby improving the transmission efficiency of the ship shaft system and the degree of fit of the corresponding ship.

[0106] Figure 7 yes Figure 4 Schematic diagram of the process included in S230. Figure 7 , S230 determines the bending moment of the transmission shaft in the transverse radial direction including:

[0107] S2301. Determine the axial force of the propeller on the transmission shaft.

[0108] Optionally, S2301 determines that the axial force of the propeller acting on the transmission shaft includes:

[0109] S2301a. Obtain the maximum and minimum values ​​of the axial force of the propeller acting on the transmission shaft in at least two rotation cycles of the propeller.

[0110] S2301b. Take the average value of the maximum value and the minimum value of the axial force of the propeller acting on the transmission shaft in at least two rotation cycles of the propeller as the axial force of the propeller acting on the transmission shaft.

[0111] Exemplarily, in each rotation cycle, the axial force Fx of the propeller 300 on the transmission shaft 200 increases first, reaches a maximum value, and then decreases. The angle of the axial force Fx of the propeller 300 on the transmission shaft 200 increases first, reaches a maximum value, and then decreases. Therefore, it is necessary to determine the axial force of the propeller on the transmission shaft based on the average value of the maximum value and the minimum value of the axial force of the propeller on the transmission shaft in at least two rotation cycles of the propeller, thereby improving the accuracy of the axial force of the propeller on the transmission shaft.

[0112] S2302. Obtain an average value of the longitudinal radial displacement of the axis center of the transmission shaft in at least two rotation cycles of the propeller.

[0113] Exemplarily, in each rotation cycle, under the action of the axial force Fx exerted by the propeller 300 on the transmission shaft 200, the displacement Z of the axis of the transmission shaft 200 in the longitudinal radial direction will change periodically. Specifically, the bending moment My of the transmission shaft in the transverse radial direction can be calculated by taking the average value of the maximum value and the minimum value of the displacement Z of the axis of the transmission shaft in the longitudinal radial direction in at least two rotation cycles of the propeller, thereby improving the accuracy of the bending moment My of the transmission shaft in the transverse radial direction.

[0114] S2303. Determine the bending moment of the transmission shaft in the transverse radial direction according to the product of the axial force of the propeller acting on the transmission shaft and the average displacement of the axis of the transmission shaft in the longitudinal radial direction within at least two rotation cycles of the propeller.

[0115] On the basis of the above technical solution, the embodiment of the present invention further defines a method for calculating the bending moment of the transmission shaft in the transverse radial direction at each bearing. Fig.11 In each rotation cycle, under the action of the axial force Fx exerted by the propeller 300 on the transmission shaft 200, the bending moment My of the transmission shaft 200 in the transverse radial direction will change periodically. The bending moment of the transmission shaft in the transverse radial direction is calculated by taking the average value of the maximum value and the minimum value of the displacement of the axis of the transmission shaft in the longitudinal radial direction in at least two rotation cycles of the propeller, thereby improving the accuracy of the bending moment of the transmission shaft in the transverse radial direction, thereby improving the transmission efficiency of the ship shaft system and the degree of fit of the corresponding ship.

[0116] For example, the reaction force F of the intermediate shaft bearing 401 is a is 168005N, the friction coefficient of the intermediate shaft bearing 401 is μ a is 0.04, the radius r of the transmission shaft of the intermediate shaft bearing 401 a is 0.365m; the support reaction force F of the stern tube front bearing 402 b is 161582N, the friction coefficient of the stern tube front bearing 402 is μ bis 0.04, the radius r of the transmission shaft of the stern tube front bearing 402 b 0.405m; Support reaction force F at node C of stern tube rear bearing 403 c is 148777N, and the friction coefficient μ at the node C of the rear bearing 403 of the stern tube is c is 0.04, the radius r of the transmission shaft at the node C of the rear bearing 403 of the stern tube c is 0.405m; the support reaction force F at the node D of the rear bearing 403 of the stern tube d is 696924N, and the friction coefficient μ at the node D of the rear bearing 403 of the stern tube is d is 0.04, the radius r of the transmission shaft at the node D of the rear bearing 403 of the stern tube d is 0.405 m, and the angular velocity ω of the transmission shaft 200 is 2*π*62 / 60 rad / s. The output power Ps of the engine 100 is 19000 KW.

[0117] Referring to formula (2), after calculation, the transmission efficiency of the ship shaft system is 0.9936.

[0118] Embodiment 3

[0119] Fig.12 is a schematic diagram of the structure of a device for calculating the transmission efficiency of a ship shaft system provided according to a third embodiment of the present invention; Fig.13 It is a structural schematic diagram of an electronic device for calculating a method for transmission efficiency of a ship shafting according to an embodiment of the present invention.

[0120] See also Fig.12 The device for calculating the ship shafting transmission efficiency comprises: a support reaction force determination module 500, which is used to determine the support reaction force of each bearing; and a ship shafting transmission efficiency determination module 600, which is used to determine the ship shafting transmission efficiency according to the support reaction force of each bearing.

[0121] The ship includes an engine, a transmission shaft and a propeller. The output shaft of the engine drives the transmission shaft to rotate, and the transmission shaft drives the propeller to rotate. N bearings are arranged on the transmission shaft, and the number N is greater than or equal to 1. Figure 2 The shaft transmission structure of the ship includes an engine 100, a transmission shaft 200 and a propeller 300. The output shaft of the engine 100 drives the transmission shaft 200 to rotate, and the transmission shaft 200 drives the propeller 300 to rotate. The transmission shaft 200 is provided with N bearings, and the number N is greater than or equal to 1. Exemplary, Figure 2 3 bearings are shown in FIG. 4 , which are the intermediate shaft bearing 401, the stern tube front bearing 402 and the stern tube rear bearing 403. Since the stern tube rear bearing 403 is relatively long, Figure 3In the mechanical simulation diagram of the shaft transmission structure of the ship shown, the support reaction force of the stern tube rear bearing 403 is simulated by the support reaction force Fc received by node C and the support reaction force Fd received by node D. The support reaction force of the stern tube front bearing 402 is simulated by the support reaction force Fb received by node B. The support reaction force of the intermediate shaft bearing 401 is simulated by the support reaction force Fa received by node A.

[0122] The technical solution provided by the embodiment of the present invention provides designers with a calculation device for determining the shafting transmission efficiency of a ship based on the support reaction force of each bearing in a specific ship, thereby improving the accuracy of the shafting transmission efficiency of the ship obtained by the designer, thereby improving the consistency between the shafting transmission efficiency of the ship and the corresponding ship.

[0123] Embodiment 4

[0124] Fig.13 It is a structural schematic diagram of an electronic device for a method for calculating the transmission efficiency of a ship shaft system provided in a fourth embodiment of the present invention.

[0125] Electronic devices are intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframes, and other suitable computers. Electronic devices may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the invention described and / or claimed herein.

[0126] like Fig.13 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0127] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0128] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as a method for calculating the transmission efficiency of a ship shafting system.

[0129] In some embodiments, the calculation method of the ship shafting transmission efficiency may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the calculation method of the ship shafting transmission efficiency described above may be performed. Alternatively, in other embodiments, the processor 11 may be configured to execute the calculation method of the ship shafting transmission efficiency by any other appropriate means (e.g., by means of firmware).

[0130] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0131] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0132] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0133] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0134] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0135] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0136] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0137] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for calculating the transmission efficiency of a ship shaft system, wherein the ship comprises an engine, a transmission shaft and a propeller, wherein the output shaft of the engine drives the transmission shaft to rotate, and the transmission shaft drives the propeller to rotate, and the transmission shaft is provided with N bearings, wherein the number N is greater than or equal to 1, and wherein: include: determining a support reaction force of each of the bearings; Determining the shafting transmission efficiency of the ship according to the support reaction force of each bearing; Determining the shafting transmission efficiency of the ship according to the support reaction force of the bearing includes: The shafting transmission efficiency of the ship satisfies the following relationship: Among them, η s is the shafting transmission efficiency of the ship, F i is the reaction force of the ith bearing, μ i is the friction coefficient at the i-th bearing, r i is the radius of the transmission shaft at the i-th bearing, ω is the angular velocity of the transmission shaft, and Ps is the output power of the engine.

2. The method for calculating the ship shafting transmission efficiency according to claim 1, characterized in that: Determining the support reaction force of each of the bearings includes: Determining the resultant force of the propeller acting in the radial direction of the transmission shaft; Determining the bending moment of the transmission shaft in the longitudinal and radial directions; Determining the bending moment of the transmission shaft in the transverse radial direction; The support reaction force of each bearing is determined according to the resultant force of the propeller acting in the radial direction of the transmission shaft, the bending moment of the transmission shaft in the longitudinal radial direction and the bending moment of the transmission shaft in the transverse radial direction.

3. The method for calculating the ship shafting transmission efficiency according to claim 2, characterized in that: Determining the resultant force of the propeller acting in the radial direction of the transmission shaft includes: Obtaining an average value of the transverse and radial forces of the propeller acting on the transmission shaft during at least two rotation cycles of the propeller; Obtaining an average value of the longitudinal and radial forces of the propeller acting on the transmission shaft during at least two rotation cycles of the propeller; The resultant force of the propeller in the radial direction acting on the transmission shaft is determined based on an average value of the transverse radial force of the propeller acting on the transmission shaft in at least two rotation cycles of the propeller and an average value of the longitudinal radial force of the propeller acting on the transmission shaft in at least two rotation cycles of the propeller.

4. The method for calculating the ship shafting transmission efficiency according to claim 2, characterized in that: Determining the bending moment of the transmission shaft in the longitudinal radial direction includes: determining an axial force exerted by the propeller on the transmission shaft; Obtaining an average value of the displacement of the transmission shaft in the transverse radial direction during at least two rotation cycles of the propeller; The bending moment of the transmission shaft in the longitudinal radial direction is determined according to the product of the axial force of the propeller acting on the transmission shaft and the average displacement of the axis center of the transmission shaft in the transverse radial direction within at least two rotation cycles of the propeller.

5. The method for calculating the ship shafting transmission efficiency according to claim 2, characterized in that: Determining the bending moment of the transmission shaft in the transverse radial direction includes: determining an axial force exerted by the propeller on the transmission shaft; Obtaining an average value of the displacement of the axis of the transmission shaft in the longitudinal radial direction during at least two rotation cycles of the propeller; The bending moment of the transmission shaft in the transverse radial direction is determined according to the product of the axial force of the propeller acting on the transmission shaft and the average displacement of the axis center of the transmission shaft in the longitudinal radial direction within at least two rotation cycles of the propeller.

6. The method for calculating the ship shafting transmission efficiency according to claim 4 or 5, characterized in that: Determining the axial force of the propeller acting on the transmission shaft includes: Obtaining a maximum value and a minimum value of an axial force exerted by the propeller on the transmission shaft in at least two rotation cycles of the propeller; The average value of the maximum value and the minimum value of the axial force exerted by the propeller on the transmission shaft in at least two rotation cycles of the propeller is taken as the axial force exerted by the propeller on the transmission shaft.

7. A device for calculating the transmission efficiency of a ship shaft system, wherein the ship comprises an engine, a transmission shaft and a propeller, wherein the output shaft of the engine drives the transmission shaft to rotate, and the transmission shaft drives the propeller to rotate, and the transmission shaft is provided with N bearings, wherein the number N is greater than or equal to 1, and wherein: include: A support reaction force determination module, the support reaction force determination module is used to determine the support reaction force of each of the bearings; A ship shafting transmission efficiency determination module, the ship shafting transmission efficiency determination module is used to determine the ship shafting transmission efficiency according to the support reaction force of each bearing; Determining the shafting transmission efficiency of the ship according to the support reaction force of the bearing includes: The shafting transmission efficiency of the ship satisfies the following relationship: Among them, η s is the shafting transmission efficiency of the ship, F i is the reaction force of the ith bearing, μ i is the friction coefficient at the i-th bearing, ri is the radius of the transmission shaft at the i-th bearing, ω is the angular velocity of the transmission shaft, and Ps is the output power of the engine.

8. A device for calculating the transmission efficiency of a ship shaft system, characterized in that: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for calculating the ship shafting transmission efficiency according to any one of claims 1-6.

9. A computer instruction, wherein the computer instruction is used to implement the method for calculating the ship shafting transmission efficiency according to any one of claims 1 to 6 when executed by a processor.

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