Turbine generator
涡轮发电机
A generator can be broadly defined as a device that converts a form of energy into electricity. Nearly all of the electricity consumers use is produced by generators that convert kinetic (mechanical) energy into electrical energy. Generators operate because of the relationship between magnetism and electricity. In 1831,scientist Michael Faraday discovered that when a magnet is moved inside a coil of wire, an electric current flows in the wire.
广义上讲,发电机是把其他形式的能转换成电能的装置。人们使用的所有的电几乎都是利用发电机把动能(机械能)转换成电能而来的。发电机的工作原理是利用了电与磁的相互作用(电磁感应定律)。1831年,科学家迈克尔?法拉第发现,当磁铁在线圈中运动时,线圈里就会产生电流。
The most widely used method of producing electricity uses generators with an electromagnet-a magnet produced by electricity-not a traditional magnet. The generator has a series of insulated coils of wire that form a stationary cylinder. This cylinder surrounds a rotary electromagnetic shaft. When the electromagnetic shaft rotates, it induces a small electric current in each section of the wire coil. Each section of the wire coil becomes a small, separate electric conductor. The small currents of the individual sections are added together to form one large current. This current is the electricity that is transmitted from generators to consumers.
最常见的发电方法是用装有电磁铁的发电机发电,电磁铁不是一般的磁体,而是通电后产生电磁的磁体。发电机上有很多匝互相绝缘的闭合线圈,形成固定圆筒。圆筒内包裹着一个旋转电磁轴。当电磁轴转动,每一匝闭合线圈中就会形 成微弱的感应电流。这样每一匝闭合线圈就形成了一个独立的小型电导体。线圈中的电流汇集成一股强大的电流,发电机就产生了可供人们使用的电。
An electric power plant uses a turbine or other similar machine to drive these types of generators. There are steam turbines, gas combustion turbines, water turbines, and wind turbines. Steam turbines using biomass, coal, geothermal energy, natural gas, nuclear energy, and solar thermal energy produce about 70% of the electricity used in the United States. These power plants are about 35% efficient. That means that for every 100 units of primary heat energy that go into a power plant, only 35 units are converted to useable electrical energy.
电厂使用涡轮机或类似的装置来带动这些类型的发电机发电。涡轮机分为汽轮机、燃气轮机、水轮机、风轮机。美国70%的发电量是使用汽轮机将生物能、煤、地热能、天然气、核能、太阳(热)能转换为电能。电厂的能量转换效率为 35%左右,即最初投入100单位的热能中只有35单位的热能转换成了电能。
Other types of devices that generate or produce electricity include electrochemical batteries, fuel cells, solar photovoltaic cells, and thermoelectric generators.
其他可发电的装置还有电化学电池、燃料电池、太阳能光伏电池、热力发电机。
Magnets and Electricity
电与磁
The spinning of the electrons around the nucleus of an atom creates a tiny magnetic field. The electrons in most objects spin in random directions, and their magnetic forces cancel out each other. Magnets are different because the molecules in magnets are arranged so that their electrons spin in the same direction. This arrangement and movement creates a magnetic force that flows from a north-seeking pole and a south-seeking pole. The magnetic force creates a magnetic field around a magnet.
原子中,电子围绕原子核旋转会产生一个微弱的磁场。大多数物体中电子无 规律旋转,因而它们产生的磁力相互抵消。而磁体有所不同。磁体内部的分子排 布使其电子朝一个方向旋转。这种排布和运动产生了由北极指向南极的磁力。这 种磁力在磁体周围形成磁场。
Have you ever held two magnets close to each other? They don’t act like most objects. If you try to push the same poles together, they repel each other. But if you put different poles together, the magnets will stick together because the north and south poles are attracted to each other. Just like protons and electrons-opposites attract with magnets.
你有曾将两块磁铁彼此靠近吗?它们跟其他物品不一样。如果把相同的磁极 放在一起,它们彼此排斥。但是如果是不同的磁极的话,就相互吸引。与质子和电子一样,磁体的不同磁极相互吸引/磁体也是异性相吸。
Magnetic fields can be used to make electricity磁场可以用来发电
The properties of magnets can be used to make electricity. Moving magnetic fields can pull and push electrons. Metals such as copper have electrons that are loosely held, so the electrons in copper wires can easily be pushed from their shells by moving magnets.
磁体的特性可以用来发电。移动磁场可以吸引和排斥电子。像铜这样的金属,其对电子的束缚力很弱,所以当磁体移动,铜线中的电子就很容易从电子层中逃 逸/脱离。
By using moving magnets and copper wire together, electric generators create electricity. Electric generators essentially convert kinetic energy (the energy of motion) into electrical energy.
当运动的磁体和铜导线共同作用时,发电机就产生了电能。发电机的本质是 把动能转换成了电能。