WO2013040879A1

WO2013040879A1 - Inflatable/deflatable wind turbine blade structure

Info

Publication number: WO2013040879A1
Application number: PCT/CN2012/072488
Authority: WO
Inventors: 曾攀
Original assignee: 清华大学
Priority date: 2011-09-23
Filing date: 2012-03-16
Publication date: 2013-03-28
Also published as: CN102322408A; CN102322408B

Abstract

An inflatable/deflatable wind turbine blade structure comprising a blade (11), a wind turbine wheel (14), and a wind turbine main shaft (15). The blade (11) and the wind turbine wheel housing (14) are connected, while the wind turbine wheel housing (14) is arranged on the wind turbine main shaft (15). The blade (11) comprises a frame beam (1), a front wing panel (2), and a rear wing airbag (3). The frame beam (1) is provided with a channel section, constituted by a vertical side plate (10) and upper and lower side plates. The frame beam (1) employs a constant section along a lengthwise direction of the blade (11), or employs a variable section gradually decreasing in size. The rear wing airbag (3) and the vertical side plate (10) are connected via a bolt. The rear wing airbag (3) is provided thereon with an inflation valve (4) and a deflation valve (8). The front wing panel (2) is fixed to the upper and lower side plates of the frame beam (1). Consisting of the frame beam (1), the front wing panel (2), and the rear wing panel (3), the cross section of the blade (11) is provided with an aerodynamically streamlined shape and structure. The structure has the advantages of reduced manufacturing and maintenance costs, and of improved safety.

Description

Blade structure of a gas-filled wind turbine

The invention relates to a wind turbine blade structure, in particular to a blade structure of a gas-filled wind turbine, belonging to the technical field of wind power generation equipment.

Most of today's energy sources are fossil fuels: coal, oil and natural gas. At the current rate of use, the known remaining coal deposits will be used up in about 200 years, while oil and gas will be used in less than 100 years. Do it. Fossil fuels cause a lot of environmental pollution when used, including greenhouse gases that cause global warming. Wind energy is one of the most commercial potential and most dynamic renewable energy sources. It is clean, low cost and inexhaustible. Wind power has the advantages of large space for installed capacity growth, rapid cost reduction, safety and never exhaustion of energy. Wind power can effectively alleviate air pollution, water pollution and global warming while providing a stable power supply for economic growth. In all kinds of new energy development, wind power generation is a relatively mature technology and has large-scale development and commercial development conditions. Wind power can reduce the large amount of pollutants and carbon emissions generated by fossil fuel power generation, and promote wind power on a large scale. Make positive contributions to energy conservation and emission reduction. In the context of the growing global energy crisis and environmental crisis, wind energy resources have begun to receive widespread attention. The large-scale development of wind power generation provides a broad market space and prospects for the wind power equipment manufacturing industry. It is estimated that the global potential wind power capacity exceeds 70 trillion kilowatts, which is 10 times larger than the total amount of water energy that can be developed and utilized on the earth. As the cost of conventional energy continues to rise in the future, the advantages of wind power will become more obvious and development will be faster. It is estimated that the annual average growth rate of wind power installed capacity will reach 20% in the next few years. According to the report of the Global Wind Energy Committee, the installed capacity of wind power in Germany, Spain, the United States, India, Denmark, Italy, the United Kingdom, the Netherlands, China, Japan and Portugal is relatively high. According to the Global Industry Blue Book published by Greenpeace International and the World Wind Energy Association, the installed capacity of wind power in the world will reach 1.26 billion kilowatts by 2020, when wind power will reach 3.1 trillion kilowatt hours, and wind power will account for 12% of the world's electricity supply. This clean energy will reduce about 11 billion tons of carbon dioxide emissions).

It can be seen that the use of renewable energy including solar energy, wind energy, biomass energy, etc. has entered a new period of development, and wind energy is considered to be the most promising clean energy to compete with traditional energy sources in power generation costs. The average stand-alone power of wind turbines in the European countries such as the United Kingdom and Denmark has reached 2.5 MW, and the average in China is 1.6 MW. The installation cost of offshore wind turbines is relatively high, so large-scale units have more cost advantages. The 6 MW wind turbines of Denmark Vestas will be put into use, the US Clipper The company has developed a 10MW prototype, and the next generation of offshore wind turbines will reach 6MW to 10MW.

In recent years, China's wind power industry has experienced explosive growth. From 2005, the annual installed capacity was less than 1000MW, and the installed capacity in 2009 exceeded 14,000MW. In the past five years, it has increased 14 times. During the “Twelfth Five-Year Plan” period (2011-2015), China's new wind power installed capacity will reach 40,000 MW, and China has become a global wind power country.

Wind power generation from the end of the 19th century to the beginning of the 20th century was a small-scale DC power generation. It was not until the first half of the 20th century that wind turbines were enlarged and the output power was increased by improving aerodynamic performance. By the end of the 1990s, 1MW-1.5MW wind turbines had been used on a large scale. In the 21st century, the power and wind turbine diameter of wind turbines are becoming larger, and wind turbines with a diameter of 60-80 m and an output of 2 MW are the main units. At the same time, offshore wind turbines are also larger.

Today, the latest technologies and development trends in wind power generation show trends in large-scale, variable-speed operation, pitch and gearless boxes, namely:

First, in terms of large-scale, megawatt-class wind turbines now have commercial value, and their stand-alone capacity can reach 2~3MW. At present, the largest single-unit capacity of wind turbines can reach 5MW, the length of the rotor blade is also greater than 30m, and the weight of the generator set is also heavy, which will inevitably bring greater difficulties in transportation and installation. The structural safety of the wind turbine in the strong wind also faces greater risks.

Second, in the variable speed operation, that is, compared with the wind turbine with constant speed operation, the variable speed operation fan has the advantages of large power generation, good adaptability to changes in wind speed, low production cost and high efficiency, but for large fans, The blades are longer and heavier, and control of their inertia will be a difficult point.

Third, in terms of pitch design and operation, the current fixed pitch is developing in the direction of variable pitch. The advantage of variable pitch adjustment is that the starting performance of the unit is good, the output power is stable, the unit structure is weak, and the shutdown is convenient and safe. The pitching mechanism is more complicated, and the failure probability of the pitch device is also increased, and the control program is complicated. Combined with the application of pitch technology and the development of power electronics technology, most wind turbine development and manufacturing companies began to use variable speed constant frequency technology, and developed pitch variable speed wind turbines, which made further improvement and improvement in wind energy conversion.

Fourth, in the case of gearless (direct drive), that is, the direct drive method without gearbox can effectively improve the efficiency and operational reliability of the system, but it is necessary to develop low-speed generator technology.

5. In terms of blade technology, the airfoil of wind turbine blades has evolved from the airfoil that originally used aircraft wings to the recently used airfoil specifically for wind turbines, and has a higher range in the low Reynolds number range. The lift-to-drag ratio is thicker than that of the airfoil used in the aircraft, and the strength and rigidity of the blade are also greatly improved.

In terms of blades alone, today's large-scale wind power equipment has the following disadvantages: the size of large blades is getting longer and longer, which puts higher and higher requirements on the weight, strength and rigidity of the blade materials, and also raises the manufacturing process. The requirements of the pitch design will inevitably bring about the complexity of the structure, increase the cost and the failure rate of the equipment; the blade airfoil cannot change with the change of the wind condition; although the large blade can improve the utilization of wind energy, it is also good for the wind. The structural safety under the action poses a huge risk; large blades also bring major problems in transportation and installation; at the same time, many problems are caused by the maintenance and use of the blades. In short, today's large blades have complex structures, high manufacturing and transportation costs, high equipment maintenance costs, and high safety risks.

The object of the present invention is to provide a blade structure of a gas-filled wind turbine with the advantages of complicated structure, high manufacturing and transportation cost, high equipment maintenance cost, and high safety risk in the prior art. It has the characteristics of light weight, low manufacturing and maintenance cost, and controllable wind and stress state, so as to meet the requirements of large wind turbines on blade structure.

The technical solution of the present invention is as follows:

An air-filled wind turbine blade structure comprising a blade, a fan hub and a fan main shaft, the blade is connected to the fan hub, and the fan hub is mounted on the fan main shaft, wherein the blade comprises a skeleton beam and a front wing panel And a rear wing airbag; the skeleton beam has a groove-shaped cross section, and is composed of a vertical web and upper and lower side plates, and the skeleton beam adopts an equal section along the length direction of the blade, or adopts a gradually smaller variable cross section; The rear wing airbag is connected to the vertical web by bolts, and the rear wing airbag is provided with an inflation valve and an air suction valve; the front wing panel is fixed with the upper and lower side plates of the skeleton beam; the skeleton beam and the front wing are The cross section of the blade composed of the face plate and the rear wing air bag has an aerodynamic streamlined outer shape structure.

The technical feature of the present invention is also that the rear wing airbag adopts a gradually smaller variable cross section along the length direction of the blade.

The rear wing airbag is composed of individual independent segment airbags, and each of the independent segment airbags has an inflation valve and an air suction valve. A plurality of web weight reducing holes are formed in the vertical web.

Another technical feature of the present invention is that an air pump, an air pump and a control system are arranged in the fan hub, and an inflation valve on the rear airbag is connected to the air pump through an inflation hose, and the air suction valve is softly pumped through the air pump. The tube is connected to the air pump, and the control system is respectively connected to the inflation pump and the air suction valve of the air pump, the air pump and the rear air bag through the control line.

Compared with the prior art, the invention has the following characteristics and outstanding effects: 1 the weight of the blade is greatly reduced, the starting performance of the unit is good, the structure of the unit is small, and the shutdown is convenient. 2 manufacturing and maintenance costs are low. 3 By controlling the inflation state of the airbag, the overall wind receiving state of the blade is adjusted and controlled, and the blade pitch adjustment mechanism is not required, so that the output power is stable. 4 When the wind is huge and poses a threat to the safety of the fan, all the airbags of the blade can be in a state of suction and condensation to ensure the safety of the fan. The proposed blade structure is suitable for the design and construction of large wind turbine blades.

FIG. 1 is a schematic structural view of a gas-filled wind turbine blade provided by the present invention.

Figure 2 is a schematic view of the air intake pump, air pump and control system in the hub.

In the figure: 1-frame beam; 2-front wing panel; 3- rear wing airbag; 4-web weight reduction hole; 5-inflating valve; 6-exhaust valve; 7-inflating hose; 8-exhaust hose; 9-wind direction; 10- vertical web; 11-blade; 12-inflator pump; 13-exhaust pump; Fan hub; 15-fan spindle; 16-control system.

Embodiments of the invention

The structure and specific embodiments of the present invention are further described below with reference to the accompanying drawings:

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the structure of a gas-filled wind turbine blade provided by the present invention. The blade comprises a skeleton beam 1, a front wing panel 2 and a rear wing airbag 3; the skeleton beam adopts an equal section along the length direction of the blade, or adopts a gradually smaller variable section, which is stronger near the root of the blade, and is close to The tip of the blade is weaker on one side. The rear airbag 3 adopts an integral airbag, and can also be combined by each independent segmented airbag. The independent segmented airbag can better control the blade force state; in general, the large blade adopts independent The segmented airbags are combined, and the small and medium-sized blades are in the form of integral airbags; the rear wing airbags 3 are connected to the vertical webs 10 of the skeleton beam 1 through a series of connecting bolts, and the front wing panels 2 are connected to the skeleton beam 1 by connecting screws The panel and the lower panel are fixed; after the rear airbag 3 is inflated, the cross section of the blade composed of the skeleton beam 1, the front wing panel 2 and the rear wing airbag 3 has an aerodynamic streamlined outer shape structure, and the cross section of the rear airbag 3 The tapered section is gradually smaller along the length of the blade, larger on the side near the blade root, and smaller on the side near the tip of the blade, and the airfoil midline has a windward angle α with the wind direction (the angle α) Specific calculations can be made according to the needs of the blade lift). The inflation valve 5 on the rear airbag 3 is connected to the air pump 12 through the inflation hose 7, and the air suction valve 6 is connected to the air pump 13 through the air suction hose 8, and the control system 16 is respectively connected to the air pump 12 and the air pump through the control line. 13 and the inflation valve 5 of the rear wing airbag are connected to the suction valve 6. The rear wing airbag 3 can be inflated and pumped; for the rear airbag 3 combined with a separate segment airbag, each of the segment airbags has an independent inflation valve and an air suction valve for independent inflation and Pumping operation.

In order to reduce the weight of the blade, a plurality of web weight reducing holes 4 (shown in Figure 1) may be formed in the vertical web 10 of the skeleton beam.

2 is a schematic view of an air pump, an air pump, and a control system installed in the hub. The blade 11 is connected to the fan hub 14 through a connecting bolt, and the fan hub 14 is connected to the fan main shaft 15; in the fan hub 14, an air pump 12, an air pump 13 and a control system 16 are provided, and the air hose 7 and the rear wing are provided. All the inflation valves in the airbag 3 are connected, and the other end of the inflation hose 7 is directly connected to the air pump 12; the air suction hose 8 is connected to all the suction valves in the rear airbag 3, and the other end of the air suction hose 8 Directly connected to the air pump 13, the control system 16 is connected to the air pump 12, the air pump 13 and the inflation valve and the air suction valve of the rear air bag 3 through a control line, and the control system can press the air pump 14 and the air pump 15 as needed. And the opening and closing of the inflation valve 7 and the suction valve 8 of the airbag are controlled.

In the initial operation, control is first performed by the control system 16 such that the respective inflation valves 5 of the rear airbag 3 are opened, the respective suction valves 6 are closed, and the rear airbag 3 is inflated by the inflation pump 12 through the inflation hose 7. The air in the airbag is brought to a certain pressure, and the surface of the airbag has a high hardness, and then the air pump 12 and the inflation valve 5 are closed, so that the blade 11 composed of the skeleton beam, the front wing panel and the rear wing airbag will have better The stiffness, ie the inflated blade 11 will have a streamlined profile that satisfies aerodynamics The wind can be fully utilized to drive the blades for rotation.

During operation, if the air pressure in the airbag 3 of the rear wing is decreased, when the airfoil is affected to a certain value, the air pump 12 and the inflation valve 5 are controlled by the control system 16, and then The air bag 3 is vented such that the air pressure within the air bag reaches a desired value, i.e., the blade maintains an aerodynamic, streamlined configuration.

When the wind force is large or small, for the rear wing airbag 3 adopting the respective independent segment airbag combinations, the wind receiving surface of the airbag on the blade can be controlled by controlling the inflation or pumping state of each of the independent segment airbags. The distribution of the wind receiving area is different to adjust and control the overall wind receiving state of the blade, so that the output power of the fan is relatively stable without complicated blade pitch adjusting mechanism.

When the wind is huge and poses a threat to the safety of the fan, it can be controlled by the control system 16 so that the individual inflation valves 5 of the airbag are closed, and the respective suction valves 6 are opened, and the suction pump 13 is passed through the suction hose 8 The rear wing airbag 3 performs air pumping so that all the airbags of the blade are in a pumping and contracting state, and the overall wind receiving surface of the blade will become small, and the airfoil type which does not generate lift can be made, so that the fan is not in the air. Working condition to ensure the safety of blades and fans.

Claims

A blade structure of a gas-filled wind turbine comprising a blade (11), a fan hub (14) and a fan spindle (15), the blade (11) being connected to the fan hub (14), the fan hub (14) Mounted on the fan main shaft (15), characterized in that: the blade comprises a skeleton beam (1), a front wing panel (2) and a rear wing airbag (3); the skeleton beam (1) has a groove-shaped cross section, It consists of a vertical web (10) and upper and lower side plates. The skeleton beam adopts an equal section along the length of the blade, or adopts a tapered section; the rear wing airbag (3) passes through the bolt and the vertical belly. The plate (10) is connected, and the rear wing air bag (3) is provided with an inflation valve (7) and an air suction valve (8); the front wing panel (2) is fixed to the upper and lower side plates of the skeleton beam; The cross section of the blade composed of the skeleton beam (1), the front wing panel (2) and the rear wing airbag (3) has an aerodynamic streamlined outer shape structure.
A blade structure for an air-exhaust type wind power generator according to claim 1, wherein said rear air bag (3) adopts a gradually decreasing cross section along the longitudinal direction of the blade.
A blade structure for an air-exhaust type wind power generator according to claim 1, wherein said rear air bag (3) is composed of individual independent segment air bags, each of which is independent. The segment airbags all contain an inflation valve and an exhaust valve.
A blade structure for an air-exhaust type wind power generator according to claim 1, characterized in that a plurality of web weight reducing holes (4) are formed in said vertical web (10).
A gas-filled wind turbine blade structure according to claim 1, 2, 3 or 4, characterized in that: in the fan hub (14), an air pump (12) and an air pump are provided. (13) and the control system (16), the inflation valve (5) on the rear airbag (3) is connected to the air pump (12) through the inflation hose (7), and the air suction valve (6) is passed through the air suction hose ( 8) Connected to the air pump (13), the control system (16) is connected to the air pump (12), the air pump (13), and the inflation valve (5) and the air suction valve (6) of the rear air bag through the control line.