Power machinery

A windmill, also known as a wind turbine, is a kind of power machinery that does not require fuel and uses wind as an energy source. The ancient windmill was developed from the sail, it has 6~8 canopies like sailboats, distributed around a vertical axis, and when the wind blows, it rotates around the axis like a marquee, which is called a marquee-type windmill. Due to its low efficiency, this kind of windmill has been gradually replaced by wooden cloth windmills with horizontal rotating shafts and other windmills, such as "vertical windmills", "automatic rotor windmills" and so on.

More than 2,000 years ago, China, Babylon, Persia and other countries have used ancient windmills to lift water for irrigation and mill grain. After the 12th century, windmills developed rapidly in Europe, using wind energy to lift water, heating, cooling, shipping, and power generation through windmills (wind engines).

Ancient Chinese windmills have obvious characteristics, except for the horizontal axle, the sail is sail type. The sail is not mounted radially on the axle, but on eight poles around the axle frame. The sail is again offset, i.e. the canvas is narrower on one side of the pole and wider on the other, and is pulled taut with ropes. As shown in the figure, when the wind acts on A, the sail is downwind, and the sail is perpendicular to the wind direction (the maximum force) and is tightened by the rope. When turning to position C, the sail is blown outwards and the sail surface is parallel to the direction of the wind; Return to the windward position at point E. Taking advantage of the tightness of the rope and the offset of the sail, it can take advantage of the wind or headwind, as if it were in a sail. This device allows the sail to swing freely with the wind without special resistance, and the effective wind range of the sail to rotate outward exceeds 180 degrees. If you are in position G and start to turn downwind, the sail can also use part of the wind to work in small quantities. The characteristics of this sail windmill are unique to China.

In the 7th century A.D. in Western Asia, probably in Syria, the first windmills were built. This part of the world had strong winds, almost always blowing in the same direction, so these early windmills were built in response to the prevailing winds. They did not look like the windmills we see today, but instead had vertical shafts with wings arranged vertically, similar to the wooden horses that line up a merry-go-round installation.

The first windmills appeared in Western Europe at the end of the 12th century. Some believe that soldiers who had participated in the Crusades in Palestine returned home with information about the windmills. However, the design of Western windmills is very different from that of Syria, so they may have been invented independently. Right: A typical Mediterranean windmill has a round stone tower and vertical wings mounted towards the prevailing winds. They are still used to grind grains.

Western windmills differ in that the wings rotate around the vertical plane. Because the wind is more variable in Europe than in Western Asia, the windmill has another mechanism that causes the wings to rotate in the direction the wind is coming from. Left: On the island of Hälð in St. Reis, Denmark, a modern windmill is connected to a generator that supplies electricity.

Windmills are rarely used to grind grain these days, but they are gaining a new lease of life as a means of generating electricity. The "farm with a power generation turbine" consists of a large windmill that drives the generator.

Modern windmills are mainly used for power generation, which was applied by the Danes at the end of the 19th century, and matured in the 20th century after continuous improvement, with a maximum power of 15M.

China has not had its own intellectual property rights, in 2001 in Xijundian, Xi'an Jiaotong University, Shangfudan, Shangtongji and other universities with the cooperation of a group of experts, Shanghai Mosi Electronic Equipment Co., Ltd. in less than a year, successfully developed the world's first new (H-type) vertical axis wind turbine, and the installation test was successful, obtained basic data and practical experience. In the following year, MUCE made numerous improvements and tests on the product, and by the end of 2002 the product passed all tests and met the design requirements.

Since the end of 2002, MUCE has installed more than 60 sets of vertical axis wind turbines and wind-solar complementary systems in the army, making immortal contributions to the stability of national defense!

Dutch windmills

- Kinderdijk-Elschoot's windmill system

Product Name:The Mill Netork at Kinderdijk-Elshout

No. 563-003

Report on inscription on the World Heritage List in 1997 in accordance with cultural heritage selection criteria C(I)(II) (IV): Report of the 21st Session of the World Heritage Committee

The World Heritage Committee commented:

The technology used to control seawater in the "low country" received a large donation, and the installation in the Kinderdijk area was a testament to the success of the technology. From the Middle Ages, people used water power to water the land for agriculture and residential water, and it persists to this day. There are all the facilities related to technology – ravines, pools, pumping stations, administrative buildings, and a complete range of facilities to protect the windmills.

Brief introduction:

The Netherlands is known as the "Land of Windmills", and windmills are the symbol of the Netherlands. The Netherlands is located in the Earth's prevailing westerly belt, where westerly winds blow throughout the year. At the same time, it is bordered by the Atlantic Ocean, and it is a typical country with an oceanic climate, with constant sea and land breezes all year round. This provides the Netherlands, which lacks water and power resources, with generous compensation for the use of wind power.

Windmills in the Netherlands were first introduced from Germany. In the beginning, windmills were only used for grinding powder and the like. In the 16th ~ 17th century, windmills were of particular importance to the Dutch economy. At that time, the Netherlands was the world's leading trader, and various raw materials were transported from various waterways to windmills for processing, including: timber from the Nordic countries and the Baltic States, hemp and flax seeds from Germany, cinnamon and pepper from India and Southeast Asia. In the suburbs of Rotterdam and Amsterdam, the big ports of the Netherlands, there are many mills, sawmills and paper mills with windmills. With the large-scale development of the Dutch people's land reclamation project, windmills played a huge role in this arduous project. According to the local humid and rainy climate with variable wind directions, they reformed the windmills. The first is to equip the windmill with a movable canopy. In addition, in order to be able to face the wind on all sides, they installed the canopy of the windmill on rollers. This windmill is known as a Dutch windmill.

The largest Dutch windmill is several storeys tall and has a wind wing of up to 20 meters. Some windmills are made of whole oak wood. At the end of the 18th century, there were about 12,000 windmills in the Netherlands, each with 6,000 horsepower. These windmills were used to grind grain, coarse salt, tobacco, oil extraction, roll woollen wool, felt, paper, and drain stagnant water from marshes. It is these windmills that constantly absorb and drain water, protecting two-thirds of the country's land from sinking and the threat of man-made fish and turtles. Since the 20th century, due to the development of steam engines, internal combustion engines, and turbines, the old windmills that relied on wind power have become dull and almost forgotten. However, because the windmill uses natural wind power and has no risk of pollution or exhaustion, it has not only been used by the Dutch people to this day, but has also become a new energy source today, which deeply attracts people. Currently, there are more than 2,000 windmills of all kinds in the Netherlands.

The Dutch loved their windmills and often praised them in folk songs and proverbs. Windmill buildings are always dressed up as beautifully as possible. On grand festivals, windmills are decorated with garlands, national flags and cardboard suns and stars are hung.

Kinderdijk-Elschoot, located in the Netherlands, is especially famous for its windmills and has become a unique landscape in the Netherlands. Nowhere else in the world do you have more windmills than one village in the Netherlands, Kinderdijk-Elschoot. In the 18th century, the village of Kinderdijk began to build a sturdy windmill and it is still intact. The World Heritage Committee's decision to inscribe it as a World Heritage Site is due to "the windmill network system in Kinderdijk-Elshut is an artificially crafted standout landscape that demonstrates human ingenuity and resilience." Relying on the development and application of water conservancy technology, the local people spent nearly 1,000 years to build this drainage system and successfully protected the land. ”

Kinderdijk-Elschoot Village, about 8 kilometers away from Amsterdam, the capital of the Netherlands, has 19 windmills built in the 30~40s of the 18th century, forming the largest windmill group in the world today. Each windmill is a windmill tower house, conical in shape, with walls sloping from top to bottom. The 4-liter rectangular wing of the windmill is fixed to the windmill on top of the tower. The tower is divided into several floors, which are used for sleeping and eating, and some families have lived in the windmill tower for 245 years. The windmill "Tongdi Town", which is open to the public on Saturdays in July and August every year, is a major attraction of tourism in the Netherlands.

In 1229 AD, the Dutch invented the world's first windmill, and thus began the history of human use of windmills. (Another source varies greatly in chronology, saying that the world's first windmill was born in the Netherlands in 1408) at that time was used to irrigate farmland. In the middle of the 18th century, there were as many as 10,000 windmills in the Netherlands. Most of the windmills have now been replaced by electricity, with less than 1,000 units remaining. More than 300 units are still in use. (Another source: At present, there are only 970 windmills left in the Netherlands, of which only 210 are still in use, and the rest are preserved as historical monuments.) For this reason, the second Saturday of May is designated as "Windmill Day" in the Netherlands, when all the windmills in the country turn around, attracting countless tourists.

The role of these windmills in the Netherlands is mainly to convert the wind into power from the rotation of the paddle wheels. Physically, it is the conversion of wind energy into kinetic energy, which lifts water from below, and this lifting of water has now been replaced by electrically powered pumps. Today, the Netherlands has one of the largest pumping stations in Europe.

Kinderdijk is located near Rotterdam, a village in the area known as the Albraserdan Lowlands. The purpose of these windmills was to pump out the excess water from the Alblasedan lowlands (which are below sea level) created by the Dutch from the sea, and since this lowland has always been a flood-prone area, the purpose of the windmills was to pump out the excess water and discharge it into the water storage area. If the water level reaches a certain level, the water is pumped out of the reservoir again and discharged into the river.

Since 1927 A.D., the pumping station of diesel engines has done the actual pumping work. Windmills are no longer used. However, in World War II, due to the lack of fuel for diesel engines at that time, they could not drive pumping machines, so windmills were used again, and this was the last time people used them for pumping water.

Nowadays, in the midst of the arrival of summer, windmills are once again "used". However, at this time, it is mainly used for tourists, who walk along the canals and rivers to get up close and take a closer look at the huge windmills and enjoy the picturesque scenery here. Near the location of one of the windmills, a small museum has been set up with exhibits about the life of families with windmills in the Netherlands.