Turbine generator
渦輪發(fā)電機(jī)
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.
廣義上講，發(fā)電機(jī)是把其他形式的能轉(zhuǎn)換成電能的裝置。人們使用的所有的電幾乎都是利用發(fā)電機(jī)把動(dòng)能（機(jī)械能）轉(zhuǎn)換成電能而來(lái)的。發(fā)電機(jī)的工作原理是利用了電與磁的相互作用（電磁感應(yīng)定律）。1831年，科學(xué)家邁克爾?法拉第發(fā)現(xiàn)，當(dāng)磁鐵在線圈中運(yùn)動(dòng)時(shí)，線圈里就會(huì)產(chǎn)生電流。
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.
最常見(jiàn)的發(fā)電方法是用裝有電磁鐵的發(fā)電機(jī)發(fā)電，電磁鐵不是一般的磁體，而是通電后產(chǎn)生電磁的磁體。發(fā)電機(jī)上有很多匝互相絕緣的閉合線圈，形成固定圓筒。圓筒內(nèi)包裹著一個(gè)旋轉(zhuǎn)電磁軸。當(dāng)電磁軸轉(zhuǎn)動(dòng)，每一匝閉合線圈中就會(huì)形 成微弱的感應(yīng)電流。這樣每一匝閉合線圈就形成了一個(gè)獨(dú)立的小型電導(dǎo)體。線圈中的電流匯集成一股強(qiáng)大的電流，發(fā)電機(jī)就產(chǎn)生了可供人們使用的電。
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.
電廠使用渦輪機(jī)或類(lèi)似的裝置來(lái)帶動(dòng)這些類(lèi)型的發(fā)電機(jī)發(fā)電。渦輪機(jī)分為汽輪機(jī)、燃?xì)廨啓C(jī)、水輪機(jī)、風(fēng)輪機(jī)。美國(guó)70%的發(fā)電量是使用汽輪機(jī)將生物能、煤、地?zé)崮?、天然氣、核能、太?yáng)（熱）能轉(zhuǎn)換為電能。電廠的能量轉(zhuǎn)換效率為 35%左右，即最初投入100單位的熱能中只有35單位的熱能轉(zhuǎn)換成了電能。
Other types of devices that generate or produce electricity include electrochemical batteries, fuel cells, solar photovoltaic cells, and thermoelectric generators.
其他可發(fā)電的裝置還有電化學(xué)電池、燃料電池、太陽(yáng)能光伏電池、熱力發(fā)電機(jī)。
Magnets and Electricity
電與磁
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，電子圍繞原子核旋轉(zhuǎn)會(huì)產(chǎn)生一個(gè)微弱的磁場(chǎng)。大多數(shù)物體中電子無(wú) 規(guī)律旋轉(zhuǎn)，因而它們產(chǎn)生的磁力相互抵消。而磁體有所不同。磁體內(nèi)部的分子排 布使其電子朝一個(gè)方向旋轉(zhuǎn)。這種排布和運(yùn)動(dòng)產(chǎn)生了由北極指向南極的磁力。這 種磁力在磁體周?chē)纬纱艌?chǎng)。
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.
你有曾將兩塊磁鐵彼此靠近嗎？它們跟其他物品不一樣。如果把相同的磁極 放在一起，它們彼此排斥。但是如果是不同的磁極的話，就相互吸引。與質(zhì)子和電子一樣，磁體的不同磁極相互吸引/磁體也是異性相吸。
Magnetic fields can be used to make electricity磁場(chǎng)可以用來(lái)發(fā)電
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.
磁體的特性可以用來(lái)發(fā)電。移動(dòng)磁場(chǎng)可以吸引和排斥電子。像銅這樣的金屬，其對(duì)電子的束縛力很弱，所以當(dāng)磁體移動(dòng)，銅線中的電子就很容易從電子層中逃 逸/脫離。
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.
當(dāng)運(yùn)動(dòng)的磁體和銅導(dǎo)線共同作用時(shí)，發(fā)電機(jī)就產(chǎn)生了電能。發(fā)電機(jī)的本質(zhì)是 把動(dòng)能轉(zhuǎn)換成了電能。
