How can an eggbeater generate electricity
Based on the shape of the wind blades of darieu, they can be divided into two main categories: curved blades (twilight) and straight blades (h and v, etc.), both of which are applied at home and abroad. Tilts are mainly subject to pure tension, free from centrifugal loads, and structural stress is better, but their spatial position needs to be fixed and control methods, such as transformer oars, are less costly and difficult to produce, while straight blades are generally supported by cross-strike pulls to prevent large curvatures caused by centrifugal forces, but these support can generate additional aerodynamic resistance and reduce efficiency, and it is also slightly less dynamic。
Darieu wind generator for straight-leaf films (photographic source; zengen)
On the outside, the darieu wind machine and the horizontal axle wind machine are very different. In fact, since both units rely on the lifts provided by the wings across the blades, they are theoretically “synthetics”. Here's an analysis of the principles of an h-shaped darieu wind machine。
(photo source: author-made)
The wind wheel of the left-figure h-shaped darieu windmill consists of two blades parallel to the rotor axis, cross-sectioned in a symmetrical wing with a flow-shaped shape, installed in the opposite direction on both sides of the windmill's rotor axis, with the right chart listing the leaves in eight positions from 0° to 315°. The wind blows from the left to the right, and the uptight resistance generated by the cross-sectional wing of the blades drives the wind wheel, and the blades receive little resistance during normal working hours and are not marked on the map。
The fusion of lifting and resistance in the direction of the leaves is the force driving the wind wheel. An analysis of the stress of the leaves at these eight angles shows that, except for the relative wind speeds at 0° and 180° that do not produce lifts, the rise of the leaves at the other six positions can produce recoils in the direction of movement. That is to say, there are almost every angles in which the blades rotate around wind wheels in the same direction, which is why the darieu wind machine can operate under any wind direction。
The advantage of the darieu wind machine
As representatives of vertical and horizontal axis wind generators, the darieu wind engine and the horizontal axis wind engine, respectively, have experienced a long-term and intense trade-off in commercial development, which does not mean that they have no advantage at all, although the vertical axis wind machine has failed. On the contrary, in addition to the above-mentioned need to avoid the loss of energy by not adding to the wind-to-wind structure:
It's low noise pollution, and it's good for high-rises
With the large-scale development of wind farms in remote areas, wind generators are now moving closer to residential areas. However, these big guys are not as gentle as they seem, and wind blades are able to sweep the air with loud noises that affect the daily lives of the surrounding population, many of whom suffer from low-frequency noises。
The vertical axle wind machine is running at only a dozen turns, with little noise. Thus, it can take root in densely populated cities, be installed at the top of high-rise buildings, integrate wind power generation with buildings, and provide power directly to the user。
Vertical axle wind machines inside the eiffel tower (photo source: ecofriend. Com)
Vertical axis wind machine in shanghai central building (photo source: sh. Eastday. Com)
It's slow, it's bird friendly, it's strong against the wind
The horizontal axle wind machine of the three leaves is very simple, and its unique shape becomes the dotting of the natural landscape. However, at 80 m/s, it poses a great threat to birds when windfields are built close to bird habitats or bird migration routes, with numerous birds, many of them rare birds, injured or killed by impact。
The vertical axle wind machines are operating at a low rate and do not cause harm to birds. In addition, because of the low height of its towers and its strong wind resistance, there is considerable room for manoeuvre in the landing area of typhoons off our south-eastern coast。
Small unit space, low installation maintenance cost
The operation of horizontal axle wind generators produces a large tailing area behind the wind wheel, significantly affecting the performance of the rear windmills, which can only be completely eliminated if the first two units are 20 times more distant than the diameter of the wind wheel, resulting in a significant increase in the cost of laying cables and the waste of substantial land resources. In contrast, the vertical axle group is less disturbed by disturbed air currents and the test shows that wind energy can be absorbed to the maximum extent at four times the distance between the crews, so that the intense venting of the crew within the wind field can be achieved. In addition, high-quality equipment, such as vertical wind machine generators, speedboxes, etc., can be installed on the ground and can be significantly improved in mechanics and easily installed and maintained。
The tail flow from the horizontal axis wind machine at sea (photo source: energirs)
However, overall energy conversion efficiency is low in the vertical axial wind power units; speed control difficulties are encountered when operating at excess speed, and wind speed is high and it is difficult to start automatically。
In general, vertical axle wind machines appear to have more significant advantages, but wind generation requires not only demonstration of the feasibility of technology but also a combination of aerodynamic efficiency, structural safety, noise class, environmental impact, input costs and benefits。
In an intense game between the darieu wind engine and the horizontal axle wind machine, the horizontal wind generator managed in the first place in the twenty-first century and ruled the commercial wind and electricity industry completely. However, the darieu wind machine has not been eliminated, and it plays a local power function in the remote mountainous regions of the country and in the islands, such as guaranteeing the long-term operation of lighting, communications, etc。
It's the twilight of the road. Aircraft
“second spring”: offshore wind development
After entering the twenty-first century, horizontal wind turbines have gradually increased in size in order to capture more wind energy in order to reduce unit electricity generation costs. At the same time, the deficiencies of the super-large fleet of “high towers and long leaves” have become increasingly prominent, with significant ecological impacts, in addition to the inherently high operating maintenance costs. As a result, the vertical axle wind machine re-engaged into people's view, creating a wave of research on the darieu wind machine。
Based on current trends in offshore wind power development, deep-sea areas with depths above 60 metres are expected to have offshore wind capacity above 2000 gw. The data show that the darieu wind machine has more significant advantages in the deep sea environment, such as lower construction, operation and maintenance costs. In order to fully harness the potential of vertical axle wind machines, researchers have proposed a brand-new v-shaped darieu wind machine, based on the accumulation of long-term applications and advanced numerical analysis tools, and perhaps in the near future, we can see this new type of wind generator。
Innovative v-shaped darieu offshore wind generator concept (photo source: aerogenerator)
Despite the failure of the darieu wind machine during the land battle in the early twentieth century, its potential competitiveness at sea has been demonstrated by a variety of characteristics. However, there is still a long way to go before the vertical axle wind is allowed to grow up quickly after a long incipient period, to regenerate the second spring of life and to confront the mainstream horizontal wind engine chamber。
