A method, database and apparatus for propeller pitch system pressure estimation

Abstract

The application discloses a kind of pitch system pressure estimation method, database and equipment, comprising: obtaining the real-time operation data of pitch at a given time;According to the pressure and temperature measured data of hydraulic oil, the physical property parameter database of hydraulic oil is inquired, and the physical property parameter is obtained;Calculate the water power turning vane torque model, and obtain the water power turning vane torque and the calculation value of advance speed coefficient;Calculate the centrifugal force turning vane torque model, and obtain the calculation value of centrifugal force turning vane torque;Calculate the friction torque model, and obtain the calculation value of friction torque;Calculate the turning vane mechanism model, and obtain the calculation value of piston rod stroke and stress;Calculate the hub cylinder and oil distributor model, and obtain the calculation value of hydraulic oil volume flow, pressure and leakage;Calculate the control system model and proportional control valve model, and obtain the pitch system pressure estimation value.The application provides independent estimation for pitch system pressure, provides support for the operating state, fault early warning of pitch, and helps to improve the operating safety of pitch.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ship power system, in particular to a method, database and device for estimating pressure of a controllable pitch propeller system. BACKGROUND

[0002] The controllable pitch propeller is a core component of the ship power system, which can adjust the pitch of the propeller blade to change the thrust of the propeller and the direction of the propeller, convert the power of the main engine into the thrust of the ship, and thus realize the running conditions such as forward, reverse and parking, as well as the speed control or maneuvering operation, thereby improving the maneuverability and flexibility of the ship.

[0003] The controllable pitch propeller involves multiple key components such as hydraulic pump, hydraulic pipeline, filter, check valve, overflow valve, control system, proportional control valve, oil distributor, propeller hub cylinder, rotating blade mechanism and propeller blade. The load torque of the controllable pitch propeller is affected by the ship navigation state and the running state of the controllable pitch propeller. When the load torque is too large, the controllable pitch propeller may fail to adjust the pitch, which affects the normal use of the controllable pitch propeller and further affects the maneuvering and safe navigation of the ship. In extreme cases, the controllable pitch propeller may be damaged, causing huge safety risks and economic losses.

[0004] Therefore, it is of great engineering significance to establish a controllable pitch propeller mechanism model and perform real-time simulation on the pressure of the controllable pitch propeller system. SUMMARY

[0005] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present application is the lack of real-time simulation of the pressure of the controllable pitch propeller system and the low safety.

[0006] To achieve the above-mentioned purpose, on the one hand, the present application provides a method for estimating the pressure of a controllable pitch propeller system, which comprises:

[0007] S1, obtaining real-time running data of the controllable pitch propeller at a given time; querying a hydraulic oil property parameter database according to the pressure and temperature measured data of the hydraulic oil to obtain the property parameters;

[0008] S2, calculating a hydrodynamic rotating blade torque model according to the measured values of the ship main engine speed and the ship navigation speed in the real-time running data obtained in S1 to obtain the hydrodynamic rotating blade torque and the calculated value of the advance ratio;

[0009] S3, calculating a centrifugal force rotating blade torque model according to the measured value of the ship main engine speed in the real-time running data obtained in S1 to obtain the calculated value of the centrifugal force rotating blade torque;

[0010] S4, calculating a friction torque model according to the measured value of the pitch angle in the real-time running data obtained in S1 and the calculated value of the advance ratio obtained in S2 to obtain the calculated value of the friction torque;

[0011] S5, calculating the turning vane mechanism model according to the water power turning vane torque calculation value obtained in S2, the centrifugal force turning vane torque calculation value obtained in S3 and the friction torque calculation value obtained in S4, to obtain the piston rod stroke and the piston rod force calculation value;

[0012] S6, calculating the hub cylinder and oil distributor model according to the piston rod stroke and the piston rod force calculation value obtained in S5, to obtain the hydraulic oil volume flow entering the A and B cylinders, the A and B port pressure and the oil distributor A and B port leakage calculation value;

[0013] S7, calculating the control system model and the proportional control valve model according to the pitch angle setting value signal in the real-time running data obtained in S1, the hydraulic oil volume flow entering the A and B cylinders, the A and B port pressure and the oil distributor A and B port leakage calculation value obtained in S6, to obtain the pitch system pressure estimation value.

[0014] The model of the pitch system pressure change process is established, the real-time estimation of the pitch of the controllable pitch propeller is realized, the real-time estimation value of the pitch system pressure can be calculated according to the measured data of the measuring point, and the result can be used as the independent estimation of the pitch system pressure.

[0015] In the preferable embodiment of the present application, in S1, the real-time running data includes the setting value signal θ sp of the pitch angle, the measured value of the pitch angle θ e , the ship main engine rotating speed n sh , the ship navigation speed v and the hydraulic oil temperature T.

[0016] Preferably, the input signal of the hydraulic oil property parameter database includes the hydraulic oil temperature T, and the output signal includes the density ρ and the dynamic viscosity μ of the hydraulic oil.

[0017] In another preferable embodiment of the present application, in S2, the water power turning vane torque model is:

[0018] M sh = K w ρ e n 2 D 5

[0019] In the formula, M sh is the water power turning vane torque, unit: N·m; K sh is the water power turning vane torque coefficient, dimensionless; ρ w is the density of water, kg / s; n e is the rotating speed of the ship main engine, rad / s; and D is the diameter of the propeller, m.

[0020] Preferably, the water power turning vane torque coefficient K shAccording to the pitch angle and the advance coefficient, the running state database of the controllable pitch propeller is inquired to obtain;

[0021] Preferably, the advance coefficient j is calculated by the following formula:

[0022]

[0023] In the formula, j is the advance coefficient, dimensionless; v is the ship sailing speed, m / s.

[0024] In another preferred embodiment of the present application, in S3, the centrifugal force rotating blade moment model is:

[0025] M sc =F c,x y+F c,y x

[0026] In the formula, M sc is the centrifugal force rotating blade moment, N·m; y is the direction of the propeller shaft axis; z is the direction of the propeller hub axis; x is the direction perpendicular to the y-axis and z-axis plane; F c,x and F c,y are the components of the centrifugal force F c in the x direction and the y direction, N.

[0027] Preferably, the centrifugal force F c is calculated by the following formula:

[0028]

[0029] In the formula, ρ b is the propeller blade density, kg / s.

[0030] Preferably, the components F c,x and F c,y of the centrifugal force F c in the x direction and the y direction are calculated by the following formulas, respectively:

[0031] F c,x =4πρ b n e 2 ∫∫∫xdxdydz

[0032] F c,y =4πρ b n e 2 ∫∫∫ydxdydz.

[0033] In another preferred embodiment of the present application, in S4, the friction moment model is:

[0034] M sf =M sf,1 +Msf,2 +M sf,3

[0035] In the formula, M sf,1 is the friction force generated by the resultant force on the radial bearing, M sf,2 is the friction torque generated by the resultant bending moment on the plane bearing, M sf,3 is the friction torque generated by the centrifugal force of the blade on the plane bearing;

[0036] Preferably, the friction torque generated by the resultant force on the radial bearing M sf,1 is calculated by the following formula:

[0037]

[0038] In the formula, T is the thrust, N; F Q is the tangential force, N; f is the friction coefficient, dimensionless; d r is the diameter of the radial bearing, m;

[0039] Preferably, the thrust T and the tangential force F Q are calculated according to the measured value of the pitch angle θ, the rotation speed of the main engine of the ship n e and the calculated value of the advance coefficient j to query the database of the operating state of the controllable pitch propeller;

[0040] Preferably, the friction torque generated by the resultant bending moment on the plane bearing M sf,2 is:

[0041]

[0042] In the formula, R t is the thrust radius, m; R f is the tangential force radius, m;

[0043] Preferably, the thrust radius R t is calculated by the following formula:

[0044]

[0045] In the formula, R is the radius of the blade, m; r b is the hub radius, m;

[0046] Preferably, the tangential force radius R f is calculated by the following formula:

[0047]

[0048] Preferably, the friction torque generated by the centrifugal force of the blade on the plane bearing Msf,3 is calculated by the following formula:

[0049]

[0050] Where D c,o D is the outer diameter of the crank disk, m; c,i is the diameter of the contact surface between the crank disk and the hub body, m.

[0051] In another preferred embodiment of the present invention, in S5, the blade rotating mechanism model is:

[0052]

[0053]

[0054] Where h stem is the piston rod stroke, m; R crank is the radius of the crankshaft at the crank position, m; θ is the pitch angle, deg; N is the number of blades, dimensionless; J is the moment of inertia of the blades, kg·m 2 ; F stem is the force on the piston rod, N; m stem is the mass of the piston rod, kg.

[0055] In another preferred embodiment of the present invention, in S6, the hub cylinder model is:

[0056]

[0057] F stem =p B π(d cylinder 2 -d stem 2 )-p A πd cylinder 2

[0058] Where, d cylinder is the diameter of the hub cylinder, m; d stem is the diameter of the piston rod, m; h stem is the piston rod stroke, m; m stem is the mass of the piston rod, kg; F stem is the force on the piston rod, N; Q A and Q B are the hydraulic oil volume flow rates entering cylinders A and B respectively; p A and p B are the pressures at ports A and B, Pa respectively;

[0059] Preferably, the oil dispenser model is:

[0060]

[0061] Where Q leak,Aand Q leak,B respectively are the leakage of the oil distributors A, B, m3 / s; h A and h B respectively are the gap length of the oil distributors A, B, m; r A and r B respectively are the gap distance of the oil distributors A, B, m; ε e is the eccentricity correction coefficient, dimensionless; p0 is the atmospheric pressure, Pa; μ is the dynamic viscosity of the hydraulic oil, Pa·s;

[0062] Preferably, the eccentricity correction coefficient ε e is calculated by the following formula:

[0063] ε e = 1 + 1.5e 2

[0064] In the formula, e is the eccentricity of the oil distributor, mm.

[0065] In another preferred embodiment of the present application, in S7, the control system model is:

[0066]

[0067] In the formula, s is the Laplace operator; y cv is the output result of the controller, dimensionless; K P is the gain of the control system, dimensionless; τ I and τ D are respectively the integral time constant and the differential time constant of the control system, s; θ sp is the set value signal of the pitch angle in the real-time operation data obtained in S1; θ t-1 is the real-time estimated value of the pitch angle calculated in the previous beat, deg;

[0068] Preferably, the proportional control valve spool displacement x cv is calculated by the following formula:

[0069]

[0070] In the formula, τ cv is the time constant of the proportional control valve, s; x cv is the proportional control valve spool displacement, m; x cv,max is the maximum displacement of the proportional control valve spool, m;

[0071] Preferably, the proportional control valve model is:

[0072]

[0073] Q A = Qp-A -Q A-T -Q leak,A

[0074] Q B = Q P-B -Q B-T -Q leak,B

[0075] wherein p sys is the pressure of the controllable pitch propeller system, Pa; Q P-A , Q P-B , Q A-T , Q B-T are the hydraulic oil volume flow rates in the P-A, P-B, A-T, B-T flow passages of the proportional control valve, m 3 / s; A P-A , A P-B , A A-T , A B-T are the flow areas of the P-A, P-B, A-T, B-T flow passages of the proportional control valve, m 2 ; C cv is the flow coefficient of the proportional control valve, dimensionless;

[0076] Preferably, the flow areas A P-A , A P-B , A A-T , A B-T of the P-A, P-B, A-T, B-T flow passages of the proportional control valve are calculated using the following formulas, respectively:

[0077]

[0078] A P-A = A B-T

[0079] A P-B = A A-T

[0080] wherein R cv is the equivalent radius of the proportional control valve, m; x P-A and x P-B are the opening displacements of the P-A and P-B flow passages of the proportional valve, respectively;

[0081] Preferably, the equivalent radius R cv of the proportional control valve is calculated using the following formula:

[0082]

[0083] wherein A cv,max is the maximum flow area of the spool of the proportional control valve, m 2 .

[0084] In another aspect, the application provides a database for the propeller pitch system pressure estimation method, the database being a propeller pitch system operating state database, input signals of the database including a pitch angle, a ship main engine rotating speed and a speed coefficient;

[0085] Output signals of the database including a hydrodynamic blade torque coefficient, a thrust and a tangential force;

[0086] Data in the database are obtained according to computational fluid dynamics simulation.

[0087] In another preferred embodiment of the application, the data range of the pitch angle is specified as -25°-35°, for example, -25°, -10°, -5°, 0°, 5°, 10°, 20°, 30° or 35°.

[0088] The data range of the ship main engine rotating speed is specified as 10rpm-210rpm, for example, 10rpm, 50rpm, 100rpm, 110rpm, 150rpm, 200rpm or 210rpm.

[0089] The data range of the speed coefficient is specified as -0.5-1, for example, -0.5, -0.2, 0, 0.2, 0.5, 0.8, 1.

[0090] In another aspect, a device for the propeller pitch system pressure estimation method is provided, the device being a mechanism model required for propeller pitch system pressure calculation, including a hydrodynamic blade torque model, a centrifugal force blade torque, a friction torque model, a blade mechanism model, a boss cylinder, an oil distributor model, a control system model and a proportional control valve model.

[0091] Technical effects

[0092] The application realizes real-time estimation of propeller pitch system pressure, and can calculate real-time estimation value of the propeller pitch system pressure according to measured point data, which can be used as independent estimation of the propeller pitch system pressure.

[0093] In the operation process of the propeller pitch, the method provided by the application can be used for short-term prediction of the propeller pitch system pressure, which can help ship drivers to predict the influence of pitch operation on the system pressure, and further provide guarantee for safe operation of the propeller pitch.

[0094] The application provides independent estimation of the propeller pitch system pressure, which provides support for analysis of operating state of the propeller pitch and early warning of faults, and helps to improve the operation safety of the propeller pitch.

[0095] The concept, specific structure and technical effects of the present application will be further described below in combination with the drawings, so as to fully understand the purpose, features and effects of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0096] Figure 1 is a propeller pitch system pressure estimation method of a preferred embodiment of the present application;

[0097] Figure 2 is a propeller pitch angle set value signal and a measured value in real-time running data of a preferred embodiment of the present application;

[0098] Figure 3 is a measured value and a real-time estimated value of propeller pitch system pressure of a preferred embodiment of the present application. DETAILED DESCRIPTION

[0099] The present application can be embodied in many different forms and the scope of the present application is not limited to the embodiments set forth in the following description.

[0100] In the drawings, components of the same structure are denoted by the same reference numerals, and components having similar structures or functions are denoted by similar reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present application is not limited to the size and thickness of each component. In order to make the drawing clearer, the thickness of some components is appropriately exaggerated in some places in the drawing.

[0101] As shown in Figure 1 , the present application provides a propeller pitch system pressure estimation method, the method comprising:

[0102] S1, acquiring real-time running data of a propeller at a given time; querying a hydraulic oil property parameter database according to the measured data of the pressure and temperature of the hydraulic oil to obtain property parameters;

[0103] S2, calculating a water power turning blade torque model according to the measured values of the ship main engine speed and the ship sailing speed in the real-time running data obtained in S1 to obtain water power turning blade torque and advance coefficient calculation values;

[0104] S3, calculating a centrifugal force turning blade torque model according to the measured value of the ship main engine speed in the real-time running data obtained in S1 to obtain a centrifugal force turning blade torque calculation value;

[0105] S4, calculating a friction torque model according to the measured value of the propeller pitch angle in the real-time running data obtained in S1 and the advance coefficient calculation value obtained in S2 to obtain a friction torque calculation value;

[0106] S5, calculating the swash plate mechanism model according to the water power turning vane moment calculation value obtained in S2, the centrifugal force turning vane moment calculation value obtained in S3 and the friction torque calculation value obtained in S4, to obtain the piston rod stroke and the piston rod force calculation value;

[0107] S6, calculating the hub cylinder and oil distributor model according to the piston rod stroke and the piston rod force calculation value obtained in S5, to obtain the hydraulic oil volume flow into the A and B cylinders, the A and B port pressure and the oil distributor A and B port leakage calculation value;

[0108] S7, calculating the control system model and the proportional control valve model according to the pitch angle setting value signal in the real-time running data obtained in S1, the hydraulic oil volume flow into the A and B cylinders, the A and B port pressure and the oil distributor A and B port leakage calculation value obtained in S6, to obtain the pitch system pressure estimation value.

[0109] The mechanism model of the pitch system pressure change process is established, the real-time estimation of the pitch of the controllable pitch propeller is realized, the real-time estimation value of the pitch system pressure can be calculated according to the measured data of the measuring point, and the result can be used as an independent estimation of the pitch system pressure.

[0110] In the preferable embodiment of the present application, in S1, the real-time running data comprises: the setting value signal θ of the pitch angle sp , the measured value of the pitch angle θ, the ship main engine rotating speed n e , the ship navigation speed v and the hydraulic oil temperature T.

[0111] Preferably, the input signal of the hydraulic oil property parameter database comprises the hydraulic oil temperature T, and the output signal comprises the density ρ and the dynamic viscosity μ of the hydraulic oil.

[0112] In another preferable embodiment of the present application, in S2, the water power turning vane moment model is:

[0113] M sh = K sh ρ w n e 2 D 5

[0114] In the formula, M sh is the water power turning vane moment, unit: N·m; K sh is the water power turning vane moment coefficient, dimensionless; ρ w is the density of water, kg / s; n e is the rotating speed of the ship main engine, rad / s; and D is the diameter of the propeller, m.

[0115] Preferably, the water power turning vane moment coefficient K shAccording to the pitch angle and the advance coefficient, the running state database of the controllable pitch propeller is inquired to obtain;

[0116] Preferably, the advance coefficient j is calculated by the following formula:

[0117]

[0118] In the formula, j is the advance coefficient, dimensionless; v is the ship sailing speed, m / s.

[0119] In another preferred embodiment of the present application, in S3, the centrifugal force rotating blade moment model is:

[0120] M sc = F c,x y + F c,y x

[0121] In the formula, M sc is the centrifugal force rotating blade moment, N·m; y is the direction of the propeller shaft axis; z is the direction of the propeller hub axis; x is the direction perpendicular to the y-axis and z-axis plane; F c,x and F c,y are the components of the centrifugal force F c in the x direction and the y direction, N.

[0122] Preferably, the centrifugal force F c is calculated by the following formula:

[0123]

[0124] In the formula, ρ b is the propeller blade density, kg / s.

[0125] Preferably, the centrifugal force F c in the x direction and the y direction F c,x and F c,y are calculated by the following formula, respectively:

[0126] F c,x = 4πρ b n e 2 ∫∫∫xdxdydz

[0127] F c,y = 4πρ b n e 2 ∫∫∫ydxdydz.

[0128] In another preferred embodiment of the present application, in S4, the friction moment model is:

[0129] M sf = M sf,1 + Msf,2 +M sf,3

[0130] wherein M sf,1 is the resultant friction force generated by the radial bearing, M sf,2 is the resultant friction torque generated by the planar bearing of the bending moment, M sf,3 is the resultant friction torque generated by the planar bearing of the centrifugal force of the blade;

[0131] Preferably, the resultant friction torque M sf,1 is calculated by the following formula:

[0132]

[0133] wherein T is the thrust force, N; F Q is the tangential force, N; f is the friction coefficient, dimensionless; d r is the diameter of the radial bearing, m;

[0134] Preferably, the thrust force T and the tangential force F Q are calculated according to the measured value of the pitch angle θ, the rotating speed of the main engine of the ship n e and the calculated value of the advance coefficient j, and the database of the operating state of the controllable pitch propeller is inquired;

[0135] Preferably, the resultant friction torque M sf,2 of the bending moment generated by the planar bearing is:

[0136]

[0137] wherein R t is the thrust radius, m; R f is the tangential force radius, m;

[0138] Preferably, the thrust radius R t is calculated by the following formula:

[0139]

[0140] wherein R is the radius of the blade, m; r b is the radius of the boss, m;

[0141] Preferably, the tangential force radius R f is calculated by the following formula:

[0142]

[0143] Preferably, the resultant friction torque Msf,3 of the centrifugal force of the blade generated by the planar bearing is calculated by the following formula:

[0144]

[0145] wherein D c,o is the outer diameter of the crank disc, m; D c,i is the diameter of the contact surface between the crank disc and the hub body, m.

[0146] In another preferred embodiment of the present application, in S5, the model of the swash plate mechanism is:

[0147]

[0148] wherein h stem is the stroke of the piston rod, m; R crank is the radius of the position of the crank disc, m; θ is the pitch angle, deg; N is the number of blades, dimensionless; J is the moment of inertia of the blades, kg·m 2 ; F stem is the force on the piston rod, N; m stem is the mass of the piston rod, kg.

[0149] In another preferred embodiment of the present application, in S6, the model of the hub cylinder is:

[0150]

[0151] F stem = p B π(d cylinder 2 -d stem 2 )- p A πd cylinder 2

[0152] wherein d cylinder is the diameter of the hub cylinder, m; d stem is the diameter of the piston rod, m; h stem is the stroke of the piston rod, m; m stem is the mass of the piston rod, kg; F stem is the force on the piston rod, N; Q A and Q B are the hydraulic oil volume flow rates into the A and B cylinders, respectively; p A and p B are the pressures at the A and B ports, respectively, Pa;

[0153] Preferably, the model of the oil distributor is:

[0154]

[0155] wherein Q leak,A and Q leak,B are the leakage amounts at the A and B ports of the oil distributor, m3 / s; hA and h B are the gap length of the oil distributor A, B, m; r A and r B are the gap spacing of the oil distributor A, B, m; ε e is the eccentricity correction coefficient, dimensionless; p0 is the atmospheric pressure, Pa; μ is the dynamic viscosity of the hydraulic oil, Pa·s;

[0156] Preferably, the eccentricity correction coefficient ε e is calculated by the following formula:

[0157] ε e = 1 + 1.5e 2

[0158] In the formula, e is the eccentricity of the oil distributor, mm.

[0159] In another preferred embodiment of the present application, in S7, the control system model is:

[0160]

[0161] In the formula, s is the Laplace operator; y cv is the output result of the controller, dimensionless; K P is the gain of the control system, dimensionless; τ I and τ D are the integral time constant and the differential time constant of the control system, s; θ sp is the set value signal of the pitch angle in the real-time operation data obtained in S1; θ t-1 is the real-time estimated value of the pitch angle calculated in the previous beat, deg;

[0162] Preferably, the proportional control valve spool displacement x cv is calculated by the following formula:

[0163]

[0164] In the formula, τ cv is the time constant of the proportional control valve, s; x cv is the proportional control valve spool displacement, m; x cv,max is the maximum displacement of the proportional control valve spool, m;

[0165] Preferably, the proportional control valve model is:

[0166]

[0167] Q A = Q p-A - Q A-T - Q leak,A

[0168] Q B = Q P-B - Q B-T - Q leak,B

[0169] wherein p sys is the propeller system pressure, Pa; Q P-A , Q P-B , Q A-T , Q B-T are the hydraulic oil volume flow rates in the P-A, P-B, A-T, B-T flow passages of the proportional control valve, m 3 / s; A P-A , A P-B , A A-T , A B-T are the flow areas of the P-A, P-B, A-T, B-T flow passages of the proportional control valve, m 2 ; C cv is the flow coefficient of the proportional control valve, dimensionless.

[0170] Preferably, the flow areas A P-A , A P-B , A A-T , A B-T of the P-A, P-B, A-T, B-T flow passages of the proportional control valve are calculated using the following equations, respectively:

[0171]

[0172] A P-A = A B-T

[0173] A P-B = A A-T

[0174] wherein R cv is the equivalent radius of the proportional control valve, m; x P-A and x P-B are the opening displacements of the P-A and P-B flow passages of the proportional valve, respectively.

[0175] Preferably, the equivalent radius R cv of the proportional control valve is calculated using the following equation:

[0176]

[0177] wherein A cv,max is the maximum flow area of the spool of the proportional control valve, m 2 .

[0178] On the other hand, the present invention provides a controllable pitch propeller operating state database for the controllable pitch propeller system pressure estimation method, wherein the input signals of the controllable pitch propeller operating state database include pitch angle, main engine speed of the ship, and advance coefficient;

[0179] The output signals of the controllable pitch propeller operation status database include hydrodynamic blade torque coefficient, thrust and tangential force;

[0180] The data in the controllable pitch propeller operating status database is obtained based on computational fluid dynamics simulation.

[0181] In another preferred embodiment of the present invention, the data interval of the pitch angle is specified to be -25° to 35°.

[0182] The data range of the main engine speed of the ship is specified to be 10 rpm to 210 rpm.

[0183] The data range of the speed coefficient is specified to be -0.5 to 1.

[0184] Different pitch angles, main engine speeds, and advance coefficients are selected at fixed intervals within the data interval, and the corresponding ship sailing speeds are calculated. The pitch angle-main engine speed-advance coefficient-ship sailing speed are used as input parameters for computational fluid dynamics simulation to calculate the hydrodynamic blade torque, thrust, and tangential force acting on the propeller blades. The hydrodynamic blade torque coefficient is calculated based on the hydrodynamic blade torque. The pitch angle-main engine speed-advance coefficient-ship sailing speed and the corresponding hydrodynamic blade torque coefficient-thrust-tangential force are recorded.

[0185] like Figure 2 FIG. 1 shows an embodiment of a pressure estimation method for a controllable pitch propeller system according to the present invention, which obtains real-time operating data of the controllable pitch propeller, including a set value signal and a measured value of the pitch angle.

[0186] like Figure 3 As shown in FIG. 1 , a comparison between the measured value and the real-time estimated value of the controllable pitch propeller system pressure in one embodiment of the present invention shows that the average error between them is 0.09 MPa.

[0187] The preferred embodiments of the present invention have been described in detail above. It should be understood that numerous modifications and variations based on the concepts of the present invention are possible without inventive effort by those skilled in the art. Therefore, any technical solution that can be derived by one skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A method of propeller pitch system pressure estimation, the method comprising: The method comprises: S1, acquiring real-time running data of the pitch propeller at a given moment; querying a hydraulic oil property parameter database according to measured data of the pressure and temperature of the hydraulic oil to obtain the property parameters; S2, calculating a water power turning vane torque model according to the measured values of the ship main engine rotating speed and the ship sailing speed in the real-time running data obtained in S1 to obtain the water power turning vane torque and the calculation value of the advance speed coefficient; S3, calculating a centrifugal force turning vane torque model according to the measured value of the ship main engine rotating speed in the real-time running data obtained in S1 to obtain the calculation value of the centrifugal force turning vane torque; S4, calculating a friction torque model according to the measured value of the pitch angle in the real-time running data obtained in S1 and the calculation value of the advance speed coefficient obtained in S2 to obtain the calculation value of the friction torque; S5, calculating a turning vane mechanism model according to the calculation value of the water power turning vane torque obtained in S2, the calculation value of the centrifugal force turning vane torque obtained in S3 and the calculation value of the friction torque obtained in S4 to obtain the calculation values of the piston rod stroke and the piston rod stress; S6, calculating a propeller hub oil cylinder model and an oil distributor model according to the calculation values of the piston rod stroke and the piston rod stress obtained in S5 to obtain the calculation values of the hydraulic oil volume flow into the A and B oil cylinders, the A and B port pressures and the oil distributor A and B port leakage; S7, calculating a control system model and a proportional control valve model according to the pitch angle setting value signal in the real-time running data obtained in S1, the calculation values of the hydraulic oil volume flow into the A and B oil cylinders, the A and B port pressures and the oil distributor A and B port leakage obtained in S6 to obtain the pitch propeller system pressure estimation value.

2. The method of claim 1, wherein In S1, the real-time running data includes: a set value signal θ of the pitch angle sp , a measured value of the pitch angle θ, a ship main engine rotating speed n e , a ship navigation speed v and a hydraulic oil temperature T; The input signal of the hydraulic oil property parameter database comprises the hydraulic oil temperature T, and the output signal comprises the density ρ and the dynamic viscosity μ of the hydraulic oil.

3. The method of claim 1, wherein In S2, the water power turning vane torque model is: M sh = K sh p w n e 2 D 5 In the formula, M sh to obtain the water power turning blade torque, unit N.m; K sh to obtain the water power turning blade torque coefficient, dimensionless; p w is the density of water, kg / s; n e is the ship main engine rotating speed, rad / s; D is the propeller diameter, m; The water power conversion blade torque coefficient K sh , according to the pitch angle and the advance coefficient, the database of the operation state of the controllable pitch propeller is inquired; The advance speed coefficient j is calculated by the following formula: In the formula, j is the advance speed coefficient, dimensionless; v is the ship sailing speed, m / s.

4. The method of claim 1, wherein In S3, the centrifugal force turning vane torque model is: M sc = F c,x y + F c,y x In the formula, M sc is a centrifugal force turning blade moment, N-m; the y direction is the direction of the shaft axis of the paddle; the z direction is the direction of the hub axis of the paddle; the x direction is the direction perpendicular to the y axis and the z axis plane; F c,x and F c,y are the components of the centrifugal force F c in the x direction and the y direction, N; The centrifugal force F c The following formula is used to calculate: Where, ρ b is the blade density, kg / s; the centrifugal force F c the components Fx and Fy in the x and y directions c,x and F c,y are calculated using the following equations, respectively: F c,x = 4πρ b n e 2 ∫∫∫xdxdydz F c,y = 4πρ b n e 2 ∫∫∫ydxdydz.

5. The method of claim 1, wherein In S4, the friction torque model is: M sf = M sf,1 + M sf,2 + M sf,3 where M sf,1 is the resultant friction force in the radial bearing, M sf,2 is the resultant friction torque in the plane bearing, M sf,3 is the friction torque in the plane bearing due to the centrifugal force of the paddle The friction torque M generated by the resultant force in the radial bearing sf,1 The following formula is used for the calculation: Where, T is thrust, N; F Q is the tangential force, N; f is the friction coefficient, dimensionless; d r is the diameter of the radial bearing, m; The thrust T and the tangential force F Q According to the measured value of the pitch angle θ, the ship main engine speed n e The measured value and the advance coefficient j calculation value query the propeller operation state database to obtain; The friction torque M generated by the resultant bending moment in the plane bearing sf,2 for: wherein R t is the thrust radius, m; R f is the tangential force radius, m; The thrust radius R t The following formula is used for the calculation: where R is the blade radius, m; r b is the hub radius, m; The tangential force radius R f The following formula is used for the calculation: The paddle centrifugal force generates a friction torque M in the plane bearing sf,3 The following formula is used for the calculation: where D c,o is the outer diameter of the crank disc, m; D c,i is the diameter of the contact surface of the crank disc and the hub body, m, F c is the centrifugal force.

6. The method of claim 1, wherein In S5, the turning vane mechanism model is: where h stem is the piston rod stroke, m; R crank is the radius of the position of the crank disk crank, m; θ is the pitch angle, deg; F stem is the force on the piston rod, N; m stem is the mass of the piston rod, kg; M sh is the water power turning vane torque, unit N·m; M sc is the centrifugal force turning vane torque, N·m; M sf is the friction torque, N·m.

7. The method of claim 1, wherein In S6, the propeller hub oil cylinder model is: F stem = p B π(d cylinder 2 -d stem 2 )-p A πd cylinder 2 where d cylinder is the diameter of the hub cylinder, m; d stem is the diameter of the piston rod, m; h stem is the piston rod stroke, m; m stem is the piston rod mass, kg; F stem is the force on the piston rod, N; Q A and Q B are the hydraulic oil volume flow rates into the A and B cylinders, respectively; p A and p B are the A and B port pressures, respectively, Pa; The oil distributor model is: wherein Q leak,A and Q leak,B are the leakage rates of the oil distributors A, B, m 3 / s; h A and h B are the gap lengths of the oil distributors A, B, m; r A and r B are the gap spacing between the ports A, B of the oil distributor, m; ε e is the eccentricity correction factor, dimensionless; p0 is the atmospheric pressure, Pa; μ is the dynamic viscosity of the hydraulic oil, Pa-s; p A and p B are the pressures at ports A and B, respectively, Pa; The eccentricity correction coefficient ε e The following formula is used for the calculation: ε e = 1 + 1.5e 2 In the formula, e is the eccentricity of the oil distributor, mm.

8. The method of claim 1, wherein, In S7, the control system model is: where s is a Laplacian operator; y cv is a controller output result, dimensionless; K P is a gain of the control system, dimensionless; τ I and τ D are an integral time constant and a differential time constant of the control system, respectively, s; θ sp is a set value signal of the pitch angle in the real-time operation data obtained in step S1; θ t-1 is a real-time estimated value of the pitch angle calculated in the previous beat, deg; Proportional control valve spool displacement x cv The following formula is used for the calculation: Where, τ cv is the time constant of the proportional control valve, s; x cv is the displacement of the proportional control valve spool, m; x cv,max is the maximum displacement of the proportional control valve spool, m; The proportional control valve model is: Q A = Q p-A - Q A-T - Q leak,A Q B = Q P-B - Q B-T - Q leak,B wherein p sys is the pressure of the controllable pitch propeller system, Pa; Q P-A , Q P-B , Q A-T , Q B-T are the hydraulic oil volume flow rates in the P-A, P-B, A-T, B-T flow passages of the proportional control valve, m 3 / s; A P-A , A P-B , A A-T , A B-T are the flow areas of the P-A, P-B, A-T, B-T flow passages of the proportional control valve, m 2 ; C cv is the flow coefficient of the proportional control valve, dimensionless; p is the density of the hydraulic oil; p A and p B are the pressures at the A and B ports; and p0 is the atmospheric pressure, Pa. The flow passage areas A of the proportional control valves P-A, P-B, A-T, B-T P-A , A P-B , A A-T , A B-T are calculated by the following equations, respectively. A P-A = A B-T A P-B = A A-T wherein R cv is the equivalent radius of the proportional control valve, m; x P-A and x P-B are the opening displacements of the P-A and P-B flow passages of the proportional valve, respectively; The proportional control valve equivalent radius R cv The following formula is used for the calculation: In the formula, A cv,max Smax is the maximum flow area of the proportional control valve spool, m 2 .

9. A database for use in the method of claim 1-8 for estimating the pressure of the controllable pitch propeller system, characterized in that, The database is a pitch propeller running state database, the input signal comprises the pitch angle, the ship main engine rotating speed and the advance speed coefficient; The output signal of the database comprises the water power turning vane torque coefficient, the thrust and the tangential force; The data in the database is obtained according to computational fluid dynamics simulation.

10. An apparatus for the pressure estimation method of the controllable-pitch propeller system according to any one of claims 1 to 8, characterized by, The device is a mechanism model required for pitch propeller system pressure calculation, comprising a water power turning vane torque model, a centrifugal force turning vane torque, a friction torque model, a turning vane mechanism model, a propeller hub oil cylinder model, an oil distributor model, a control system model and a proportional control valve model.

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