Summary of the invention
In place of above-mentioned the deficiencies in the prior art, it is an object of the invention to provide a kind of wind-driven generator leaf
Sheet and construction design method thereof, it is intended to the problem solving blade construction of the prior art design.
In order to achieve the above object, this invention takes techniques below scheme:
A kind of blade structure for wind driven generator method for designing, wherein, described method for designing includes:
A, use Weibull function model assessment wind speed, and according to the distribution curve of function model, determine startup
Wind speed and rated wind speed;
B, the setting tip-speed ratio of blade, the number of blade, aerofoil profile and rotor diameter;
C, based on Wilson's method, calculate and obtain the chord length of foline, established angle and aerofoil profile.
Described blade structure for wind driven generator method for designing, wherein, in described step B, is calculated by following
Formula estimation rotor diameter:
P=CP (1/2) ρ P (3 π π D2/* η 1* η 2=0.49V13D2 η 1 η η
Wherein, P is wind driven generator output power, and V1 is the wind speed of design, and D is rotor diameter, and ρ is empty
The density of gas, η 1 is the efficiency of generator, and η 2 is transmission efficiency.
A kind of blade of wind-driven generator using method for designing as above, wherein, described wind-driven generator leaf
Sheet is NACA4412 aerofoil profile, and the number of blade is 3, and blade is equally divided into 18 cross sections.
Described blade of wind-driven generator, wherein, described blade of wind-driven generator is glass steel material.
Described blade of wind-driven generator, wherein, described blade of wind-driven generator also includes blade monitoring device;
Described blade monitoring device includes: gather the data acquisition unit of blade run signal;With data acquisition list
Unit connects, and obtains described blade run signal, and carries out Logic judgment accordingly, output corresponding control signal
Processor unit and being connected with described processor unit, obtains described control signal and performs corresponding operating
Executing agency.
Described blade of wind-driven generator, wherein, described data acquisition unit includes obtaining blade vibration acceleration
The acceleration transducer of signal and the speed probe of acquisition wheel speed signal.
Described blade of wind-driven generator, wherein, between described data acquisition unit and processor unit the most successively
It is provided with analog to digital conversion circuit;
After described blade run signal is converted to voltage signal, change through analog to digital conversion circuit, input to described place
Reason device unit.
Described blade of wind-driven generator, wherein, described blade monitoring device also includes a filter cell;
Described filter cell is connected with described processor unit, filters the signal that processor unit obtains;Described
Processor unit, after filter cell processes, calculates signal frequency mean value and exports the control signal of correspondence.
Described blade of wind-driven generator, wherein, described filter cell rejection frequency at 1.7-1.75Hz and
The signal in two stages of 3.05-3.2Hz.
Described blade of wind-driven generator, wherein, described filter cell is active filter circuit.
Beneficial effect: a kind of blade of wind-driven generator of present invention offer and construction design method thereof, uses
Blade is analyzed by dynamic (dynamical) theory, from the derivation of wind speed, to the selection of blade quantity, arrives aerofoil profile
Choose, then to the calculating to rotor diameter, the detailed key position blade to wind-driven generator is ground
Study carefully and design, it is thus achieved that the important parameter in blade construction design, be the good benefit to blade construction design
Fill.
Further, it is also provided with blade monitoring system, and is achieved in for the guarantor in blade running
Protect, effectively ensured the safety and reliability etc. of unit operation, had a good application prospect.
Detailed description of the invention
The present invention provides a kind of blade of wind-driven generator and construction design method thereof.For make the purpose of the present invention,
Technical scheme and effect are clearer, clear and definite, and the embodiment that develops simultaneously referring to the drawings is the most detailed to the present invention
Describe in detail bright.Should be appreciated that specific embodiment described herein, only in order to explain the present invention, is not used to limit
Determine the present invention.
As it is shown in figure 1, be the blade structure for wind driven generator method for designing of the specific embodiment of the invention.Described
Method for designing includes:
S100, use Weibull function model assessment wind speed, and according to the distribution curve of function model, determine
Threshold wind velocity and rated wind speed.
General, in actual life, the change of wind speed is very big, is difficult to by a kind of Mathematical Modeling accurately it
Describe out.Function through conventional estimation wind speed has Weibull function distribution and Rayleigh function to be distributed in the world
Two kinds.
Wherein, the Weibull function distribution simple and effective simulation wind speed probabilistic model of energy, is preferably to analyze wind
The instrument of energy, its expression formula is:
Wherein, K is form parameter, and without guiding principle amount, C is dimensional parameters, and dimension is m/s.And local different,
Time is different, and the parameter of K, C is the most different.And for function curve, the little C of K is little, curve is mild,
Peak moves to left.And the big C of K is big, then curve is precipitous, and peak moves to right.
As C=1, Weibull function expression formula is:
When 0 < K, < when 1, Weibull wind speed probability is the subtraction function of X;As K=1, probability distribution is finger
Number change;As K=3, close to normal distribution.
As K=2, wind velocity distributing paremeter formula is:
The probability distribution of Rayleigh function is as probability distribution during above K=2.
Threshold wind velocity for wind-driven generator: wind-driven generator is divided into vertically and horizontally two class, and every class wind
Power generator has multiple, and every kind has again plurality of specifications.Suitable wind-driven generator chosen by needs, just can obtain
Obtain more wind energy.
According to foregoing description, the peak value of Weibull function distribution curve is exactly toggle speed, to formula (1) derivation,
Can obtain
Because of C ≠ 0, K ≠ 0, so there being following formula:
Further, have
Rated wind speed for wind-driven generator: the specified wind speed of domestic wind-driven generator is about 6m/s and arrives
14m/s.The density P=ρ π of known wind energy, is r for an aerofoil profile radius, and efficiency is the wind-driven generator of η,
The Weibull function of the power of output is distributed as
The wind speed that W (V) peak value is corresponding is rated wind speed, and at this moment wind-driven generator can obtain the wind energy of maximum
Condition is
S200, the setting tip-speed ratio of blade, the number of blade, aerofoil profile and rotor diameter.In the design process,
Need some important parameters to blade, select according to actual situation, determine.
Generally in the case of without departing from scope, the wind-driven generator run under high tip-speed ratio state has
Higher wind wheel efficiency.And wind wheel tip-speed ratio λ0Equal to wind wheel blade tip linear velocity and the ratio of the wind speed of design:
The number of blade of wind wheel is then relevant with the purposes of wind-driven generator, compares λ with the sharp number of wind wheel0Unrelated.Now
Wind-driven generator be generally used for generating, it is contemplated that its operation and power output, commonly used three blade wind
Power generator.
The aerofoil profile of wind-driven generator is particularly significant to the efficiency of wind-driven generator.The wing of modern wind-driven generator
Type is essentially all employing distortion type.Distortion type manufactures relatively difficult, but can improve the utilization effect of wind energy
Rate, makes wind-driven generator be obtained in that optimal wind energy utilization efficiency.During designing airfoil, aerofoil profile should be made everywhere
Actual installation angle differ, the angle of blade root to blade tip gradually reduce, and make blade locate everywhere
In optimal state of angle of attack, thus obtain optimal lift, make blade obtain best wind energy and accept efficiency.
Using NACA4412 aerofoil profile, have noise little, relative thickness is little, and the usage factor of wind energy is high and has
There is the feature of good pneumatic property.
Concrete, can be by following formula estimation rotor diameter:
P=CP (1/2) ρ P (3 π π D2/* η 1* η 2=0.49V13D2 η 1 η η (7)
Wherein, P is wind driven generator output power, and V1 is the wind speed of design, and D is rotor diameter, and ρ is empty
The density of gas, η 1 is the efficiency of generator, and η 2 is transmission efficiency.
S300, based on Wilson's method, calculate and obtain the chord length of foline, established angle and aerofoil profile.Wilson's sets
Meter method (Wilson method for designing) is the method for most common a kind of blade design in the world.Compare
Glauer method, Wilson method have studied taper loss and the lift-drag ratio impact on blade optimum performance, and
Have studied wind wheel performance under off-design condition.Therefore comparing the former, Wilson method is the most advanced, examines
The aspect considered is wider, design the most accurate.
The fundamental formular of Wilson method is as follows:
A (1-aF)=b (1+b) λ2 (9)
Wherein, CP is the usage factor of wind energy, and usual value is to 0.45.A is the axial interference factor,
B is the interference factor of circumference, λ0For tip-speed ratio, λ is the ratio of the rotating speed at wind wheel radius r and wind speed.
F is Prantl tip loss coefficient, and f is Prantl algorithm intermediate variable;A is the number of blade of wind wheel,
R is the radius (m) of f wind wheel;R is the foline cross section distance (m) to wind wheel center;For foline inflow angle
(rad);C is foline chord length (m).
The design procedure of Wilson method specifically includes:
(1) theoretical according to foline, by blade along exhibition to the foline being divided into some parts;
(2) for each foline, with (8) as object function, with (9) optimization as condition
Problem, show that the interference coefficient a, b in each cross section and blade tip damage coefficient F;
(3) utilize (12) to calculate and flow wind direction angular motion, determine the torsional angle in each cross section;
(4) (13) are utilized to calculate chord length C;
(5) required blade chord length C and torsional angle are linearly revised, to meet structure and processing side
The requirement in face;
(6) consult the aerofoil profile data in handbook, calculate the aerofoil profile coordinate in each cross section.
The parameter designing of wind-driven generator is as follows: wind speed round (r.p.m) 15/22.5;Rated wind speed (m/s) 14.0;
Survival wind speed (m/s) 70;Rated power (kw) 750;Length of blade (mm) 2350025;Maximum chord length
(mm)225020;Pitch diameter (mm);Bolt specification M30;Number of Bolts 40;Ring flange external diameter
;Temperature range of operation (C0)-20 to+50.Determining that length of blade is 24m, wind wheel radius is 25m, blade
Maximum chord length is 2.35m, put away from blade root be 5.5m.
Result is analyzed with design:
Concrete, wind-power electricity generation airfoil type selects NACA4412 aerofoil profile, and the number of blade is 3, blade
18 cross sections are divided into it in equal size.Computer is used to run interference factor a that can draw arbitrary section, b, r
The chord length at place, the tip damages coefficient f, and torsional angle.Concrete outcome is as shown in the table:
In a particular embodiment of the present invention, described blade of wind-driven generator is glass steel material.Glass steel material
Blade light weight, intensity good and corrosion-resistant.
The composite of fiberglass is according to different compositely proportionals, and the mechanical attribute of its material is the most different.At this
The attribute definition of the bright blade material in specific embodiment is as shown in the table:
It is preferred that described blade of wind-driven generator also includes blade monitoring device.Arranging this monitoring device can
Protection blade system so that it is be in safe running status.
As in figure 2 it is shown, described blade monitoring system includes following four major functions: load during operation is supervised
Survey, dynamic balancing time monitoring, icing time monitoring, blade injury time monitoring, feedback result is expressed as pre-
Warn, shut down, detect, safeguard, regulate, design of feedback etc..
Described crop leaf measuring system mainly includes Fibre Optical Sensor, optical fibre interrogation instrument, data monitoring and biography
The parts such as the process of communication system, data, safe prediction.As it is shown on figure 3, sensor can use such as figure
Shown layout is arranged.
Described blade monitoring device includes: gather the data acquisition unit 100 of blade run signal;With data acquisition
Collection unit connects, and obtains described blade run signal, and carries out Logic judgment accordingly, and output correspondence controls letter
Number processor unit 200 and be connected with described processor unit, obtain described control signal and perform phase
The executing agency 300 that should operate.
As shown in Figure 4, for the hardware structure diagram of described monitoring device specific embodiment.Wherein, processor unit
200 is single-chip microcomputer, and executing agency 300 is relay, and data acquisition unit 100 includes multiple sensor.
The signal of the acceleration gathered by sensor can be converted to voltage signal through sensor, then passes through
It is sent directly into single-chip microcomputer after the conversion of A/D.
Then, described filter cell rejection frequency is at the letter in two stages of 1.7-1.75Hz and 3.05-3.2Hz
Number.
Finally, in 5 seconds, obtain signal frequency mean value, when mean value is less than setting value, work on;
Otherwise, relay sends the signal of shutdown.
Described data acquisition unit includes acceleration transducer and the acquisition obtaining blade vibration acceleration signal
The speed probe of wheel speed signal.
Under normal circumstances, acceleration transducer when measuring high-frequency signal, when measuring intermediate-freuqncy signal, operating speed passes
Sensor, and use displacement transducer when measuring low frequency.But, when installing inconvenient, displacement transducer can
To replace monitoring low frequency signal with acceleration transducer.Concrete, it is possible to use model is LC0750A's
Sensor, it has, and noise is low, anti-interference, low drifting, and anti-overload ability is strong, the advantage that cost performance is high.
More specifically, analog-to-digital conversion also it is disposed with between described data acquisition unit and processor unit
(A/D) circuit.After described blade run signal is converted to voltage signal, change through analog to digital conversion circuit, defeated
Enter to described processor unit.
Concrete, analog to digital conversion circuit can use MAX187, and this chip is the mould of 12 parallel-by-bits
Number converter.As it has been described above, signal delivers to MAX187 through the signal of preposition shaping and filtered voltage
In, analog quantity can produce the digital voltage amount of 12 after analog-to-digital conversion, after converting
The data of conversion can be read via single-chip microcomputer by the way of interruption.
In a particular embodiment of the present invention, described blade monitoring device also includes a filter cell.Described filter
Ripple device unit is connected with described processor unit, filters the signal that processor unit obtains;Described processor list
Unit, after filter cell processes, calculates signal frequency mean value and exports the control signal of correspondence.
More specifically, described filter cell can use active filter circuit.By low pass filter 101 and height
Bandpass filter 102 is mutually combined, and forms bandwidth-limited circuit (as shown in Figure 5).In actual use,
The input flow process of described bandwidth-limited circuit is as shown in Figure 6.First the signal of input is carried out RC network filter
Ripple and sampling, then by analog-to-digital conversion, interrupt after completing and read the result converted by subprogram, as
The input of digital band-pass filter.As it is shown in fig. 7, be the execution flow chart of described processor unit.
Described crop leaf measuring system also includes a wireless transport module, is used for transmitting instruction and signal etc..Described
Wireless transport module can use the nRF24E1 module that NORDIC company produces.This module wireless
Transceiver works under the ISM band of 2.4GHz, and has 125 frequencies, it is possible to realize point-to-point,
Peer-to-multiple peer wireless communication, but also the design changing frequency and frequency hopping can be used to avoid other interference.
8051 kernels being internally integrated enhancement mode of NRF24E1, and it is provided with the wireless receiving and dispatching of 2.4GHz
Device, 9 of 100kS/s and the analog-digital converter of 10, and be built-in with RC oscillator, SPI connects
Mouth, UART interface, PWM output, house dog and wake up timer and special mu balanced circuit etc. up.
All of high-frequency component includes that all portions such as oscillator are integrated in the inside of chip, so the performance of chip is the most steady
Fixed, the least by the interference of external environment, antijamming capability is strong.
NRF24E uses 36 pin encapsulation, has less volume and low in energy consumption, is suitable for wanting power consumption and volume
Use in the environment of asking strictly.Its transfer rate is very fast, and maximum up to 1Mb/s, sensitivity is-90
DBm, maximum transmitting power is 0dBm.As shown in Figure 8, for described signals collecting and transmission circuit
Schematic diagram.
Aspect is realized for software, the crystal oscillator of 1MHz due to selected sensor internal band, D6 interface
Receiving vibration signal, B interface receives the time data of DS1302.This single-chip microcomputer receives and is receiving host computer
After gathering the request of signal, interrupt single-chip microcomputer to wake up up from the pattern of sleep by INIT0, and then issue
Mono-ready signal " * " of nRF24E1.The when of initial NRF24E1, first have to the number of delivering letters
" # ", after waiting until to confirm, calls launching procedure, data is sent to receiver module by USART,
When monitoring the TXC position of UCSAR, it is sent, system entrance sleep state again.
The software designed herein have employed the program language programming of LabVIEW, it is simple to realizes the system collection to data
And analyzing and processing.And utilize computer to use LabVIEW program language, the emulation of complete pair signals, checking
The correctness of design.
It is understood that for those of ordinary skills, can be according to technical scheme and basis
Inventive concept in addition equivalent or change, and all these change or replace all should belong to appended by the present invention
Scope of the claims.