CN105822510A - Blade tip serialization segmentation blade and design method thereof - Google Patents

Abstract

The invention relates to a blade tip serialization segmentation blade and a design method thereof. Firstly, fan blade pneumatic design is carried out, an efficient low-resistance wing section is selected, high-precision performance of a wind turbine flow field is analyzed, and a foundation blade is generated; the foundation blade is subject to structural laying-up design, structure attribute calculation is carried out, a BLADED model is built, and blade loads are obtained; and through manual iterative modification of air operation-structure-loads, the final structure of the foundation blade is determined, according to the size of safety coefficients, the position with the minimum influence of the loads on the blade structure is judged and segmented, and the blade is divided into a blade main body segment and blade tip segments. Blade tip serialization design is carried out, the aim that one blade has multiple lengths is achieved, and the blade is suitable for various kinds of wind fields. Wind energy can be developed and used to the maximum limit, and the electric generation amount is improved; and the design cost, the production cost and the manufacturing cost of the blade are reduced.

Description

A kind of blade tip series segmented blade and its design method

technical field

The invention relates to the technical field of wind turbine blades, in particular to a design concept and process implementation of serialized and segmented blades with blade tips.

Background technique

The just-concluded Paris Climate Conference required all participating countries to further increase the emission reduction targets of their nationally determined contributions, and proposed to achieve "net zero" greenhouse gas emissions as early as possible in this century. It is expected that renewable energy will fully replace fossil energy by around 2050 at the earliest. . The Chinese government promises that non-fossil energy will account for 15% of primary energy consumption in 2020, and carbon dioxide emissions will peak around 2030 and strive to achieve it as soon as possible. 20% of primary energy consumption. Wind power is recognized as the most mature technology and the most promising renewable energy. my country is rich in wind resources. According to the China Meteorological Administration's "Detailed Investigation and Evaluation of Wind Energy Resources in China", the technically exploitable capacity of wind energy resources in the 70-meter layer is 2.6 billion kilowatts. Under the current economic and technological level, the development capacity is at least 1 billion kilowatts. With technological progress , the development space and potential will be further tapped.

As a key component of wind turbine power generation, wind turbine blades have a development trend of becoming larger and longer. The increase of the shape of the blade makes the manufacturing process more difficult, which is reflected in the greater requirement for the workshop space, the increase of the mold manufacturing cost, the reduction of the convenience of the worker's process operation, and the difficulty of controlling the blade quality. Because large blades are generally installed in coastal islands, mountainous areas, and plateaus, the wind farms are located in remote locations, with inconvenient transportation, and transportation is extremely difficult. In addition to solving the above problems, the segmented blade tip series can also effectively reduce the cost of the blade. The blade tip section is easy to install and disassemble, which can capture wind energy more effectively and reduce the load.

At present, there is no low-wind-speed blade-tip series segmented blades in China. According to the current state of the industry, the present invention proposes a novel blade tip serialized and segmented blade design.

Contents of the invention

The purpose of the present invention is to propose a new concept of fan blade design applicable to various types of wind farms—the design concept of blade tip serialization and segmented blades, which can increase the power generation of wind turbines while reducing blade design costs and manufacturing costs.

The invention discloses a blade tip serialization and segmentation blade design method, comprising the following steps:

Step 1: First, carry out the aerodynamic design of the fan blade. By selecting an airfoil with high efficiency and low resistance, CFD software is used to simulate the high-precision performance of the wind turbine flow field, including two-dimensional airfoil numerical simulation and three-dimensional blade numerical simulation, analysis, Generate a basic blade, specifications: generating power 1.5MW and above, blade length greater than 40m, blade aerodynamic efficiency cp value greater than 0.48;

Step 2: Design the structural layup of the basic blade, calculate the structural properties, establish the BLADED model, and obtain the blade load;

Step 3: Carry out preliminary structural design based on the aerodynamic shape through mutual iterative modification of aerodynamic-structure-load, calculate the load based on the structural design results, load feedback structure design, and modify the layup or aerodynamic shape of the position with a low safety factor of the structure , in the feedback calculation load, so repeated iterations, to determine the final structure of the basic blade,.

Step 4: And according to the final result of the structure check, generate the safety factor of each section and each part of the blade. Taking the tip of the blade as the starting point, within the range from the tip point to the 10% section of the total length of the blade, select the position with a safety factor greater than 1.5 and the furthest distance from the tip as the segmental section size of the tip to determine the position where the load has less influence on the blade structure For segmentation, the blade is divided into a blade body segment and a blade tip segment. Afterwards, according to the wind conditions of different wind fields, the aerodynamic structure of the blade tip section is further optimized by comprehensively considering the chord length distribution function, twist angle distribution function, and relative thickness distribution function, and more than three types of blade tip sections with different lengths are generated.

The invention also discloses a blade tip serialized segmented blade. The blade is designed by the above-mentioned method. The blade is divided into two sections: the main body section of the blade and the tip section of the blade. The main section of the blade and the tip section of the blade are connected by the blade connector The two sections are connected to form a complete blade structure.

The length range of the main section of the blade accounts for 90%~98% of the whole blade, and the main section of the blade includes the main beam, web and trailing edge beam of the main load-bearing components of the blade.

At least three types of blade tip segments with different lengths are matched with one blade body segment, and at least three types of blades with different overall lengths are formed after being assembled with the blade body segment.

The invention designs the aerodynamic shape of the blade, designs a basic blade through multi-objective optimization, and on the basis of the blade, calculates the load and checks the structure, and selects a position with low load influence to segment the blade. Divide the blade into two sections, the main section of the blade and the tip section of the blade. On the basis of determining the segment position, the aerodynamic shape of the blade is further optimized to ensure that the shape of the main section of the blade remains unchanged, and the shape and length of the tip section are changed, and at least three models are optimized. The main section of the blade is connected with the tip section of the blade through a connecting piece that is convenient for installation and disassembly. According to the different wind conditions of the wind field, the appropriate blade tip section can be replaced to match the wind turbine blades that are most conducive to the wind conditions of the wind field. Compared with traditional fan blades, the invention reduces mold manufacturing costs, and the serialization of blade tips enables a set of blades to be selected in various lengths, thereby reducing blade production costs and increasing power generation.

The present invention has following beneficial effect:

1. Carry out serial design of the blade tips, and realize a blade with multiple lengths, making the blade suitable for various types of wind farms.

2. It can maximize the utilization of wind energy and increase the power generation.

3. The design cost, production cost and manufacturing cost of the blade are reduced.

Description of drawings

Figure 1: The overall rendering of the blade tip series segmented blade.

detailed description

The present invention will be further described below in conjunction with specific examples.

A blade tip serialization segmented blade design method, comprising the following steps:

Step 1: First, carry out the aerodynamic shape design of the fan blade, and carry out a reasonable airfoil arrangement by selecting an airfoil with high efficiency and low resistance. CFD software is used to simulate the high-precision performance of the wind turbine flow field, including two-dimensional airfoil numerical simulation and three-dimensional blade numerical simulation, and a basic blade is generated. Specifications: power generation 1.5MW and above, blade length greater than 40m, The cp value of blade aerodynamic efficiency is greater than 0.48;

Step 2: Design the structural layer of the basic blade, calculate the structural properties, establish the BLADED model, and obtain the blade load by matching the parameters of the corresponding power machine;

Step 3: Carry out preliminary structural design based on the aerodynamic shape through mutual iterative modification of aerodynamic-structure-load, calculate the load based on the structural design results, load feedback structural design, and carry out ply reinforcement design or aerodynamic shape for positions with low structural safety factors Modify, then feed back the calculated load, and iterate repeatedly to determine the final structure of the basic blade.

Step 4: According to the final result of the structure check, generate the safety factor of each section and each part of the blade. Taking the tip of the blade as the starting point, within the range from the tip point to the 10% section of the total length of the blade, select the position with a safety factor greater than 1.5 and the furthest distance from the tip as the segmental section size of the tip to determine the position where the load has less influence on the blade structure For segmentation, the blade is divided into a blade body segment and a blade tip segment.

Step 5: According to the wind conditions of different wind fields, further optimize the aerodynamic structure of the tip section, and generate more than three types of tip sections with different lengths. The structure of the tip section is designed to meet the strength requirements and at the same time meet the lightning protection requirements of the blades.

A blade tip series segmented blade, the blade is designed by the above method, the blade is divided into two sections: the main section of the blade and the tip section of the blade, and the main section of the blade and the tip section of the blade are connected by the blade connector, Form a complete leaf structure. The length range of the main section of the blade accounts for 90%~98% of the whole blade, and the main section of the blade includes the main beam, web and trailing edge beam of the main load-bearing components of the blade. At least three types of blade tip segments with different lengths are matched with one blade body segment, and at least three types of blades with different overall lengths are formed after being assembled with the blade body segment.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any skilled person who is familiar with the profession, without departing from the scope of the technical solutions of the present invention, according to the technical essence of the present invention, Any simple modifications, equivalent replacements and improvements made in the above embodiments still fall within the protection scope of the technical solution of the present invention.

Claims (6)

1. a blade tip seriation subsection blade method for designing, it is characterised in that: comprise the steps:

Step 1: first carry out fan blade pneumatic design, by selecting the aerofoil profile of efficient low-resistance, uses CFD software to wind energy conversion system Flow field high precision performance carries out numerical simulation, including dimensional airfoil numerical simulation and three dimendional blade numerical simulation, generates a base Plinth blade, specification: generated output 1.5MW and more than, length of blade is more than 40m, and blade aerodynamic efficiency cp value is more than 0.48；

Step 2: this basis money blade carries out structure Lay up design, structure attribute calculates, and sets up BLADED model, obtains leaf Sheet load；

Step 3: by the mutual iteration of Aerodynamic-structure-load, carry out preliminary structure design according to aerodynamic configuration, according to structure Design result assumed (specified) load, load feedback arrangement designs, the position that design margin evaluation is low is carried out laying amendment or gas Dynamic profile amendment, then feed back assumed (specified) load, so iterate, determine basis blade final structure；

Step 4: check final result according to structure, generates each cross section of blade each piece safety coefficient.

2., with blade tip as starting point, in the range of blade tip point to vane overall length degree 10% cross section, choose safety coefficient more than 1.5 And distance blade tip farthest is as blade tip segmentation cross section, and blade is divided into blade body section and blade tip section.

3. blade tip seriation subsection blade as claimed in claim 1, it is characterised in that: according to different wind fields after step 4 Wind regime, carries out further pneumatic structure optimization to blade tip section, and optimization need to consider chord length distribution function, torsional angle distribution letter Number, relative thickness distribution function, it is ensured that blade profile smoothes out, and seamlessly transits, generate more than three sections different lengths at blade section Blade tip section.

4. a blade tip seriation subsection blade, it is characterised in that: use the method design blade described in claim 1, blade It is divided into two sections: blade body section and blade and blade apical segment, by blade connection, blade body section and blade and blade apical segment two sections is entered Row connects, and forms complete blade construction.

5. the blade tip seriation subsection blade stated such as claim 3, it is characterised in that: the length range of blade body section accounts for blade Overall 90% ~ 98%, blade body section comprises main load-carrying member girder, web and the trailing edge beam of blade.

6. the blade tip seriation subsection blade stated such as claim 3, it is characterised in that: at least three sections of different length blade tips Duan Yuyi blade body section coupling, forms, after assembling from blade body section, the blade that at least three money entire length are different.