Turbine generator
渦輪發電機
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,發電機是把其他形式的能轉換成電能的裝置。人們使用的所有的電幾乎都是利用發電機把動能(機械能)轉換成電能而來的。發電機的工作原理是利用了電與磁的相互作用(電磁感應定律)。1831年,科學家邁克爾?法拉第發現,當磁鐵在線圈中運動時,線圈里就會產生電流。
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.
最常見的發電方法是用裝有電磁鐵的發電機發電,電磁鐵不是一般的磁體,而是通電后產生電磁的磁體。發電機上有很多匝互相絕緣的閉合線圈,形成固定圓筒。圓筒內包裹著一個旋轉電磁軸。當電磁軸轉動,每一匝閉合線圈中就會形 成微弱的感應電流。這樣每一匝閉合線圈就形成了一個獨立的小型電導體。線圈中的電流匯集成一股強大的電流,發電機就產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.
電廠使用渦輪機或類似的裝置來帶動這些類型的發電機發電。渦輪機分為汽輪機、燃氣輪機、水輪機、風輪機。美國70%的發電量是使用汽輪機將生物能、煤、地熱能、天然氣、核能、太陽(熱)能轉換為電能。電廠的能量轉換效率為 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.
其他可發電的裝置還有電化學電池、燃料電池、太陽能光伏電池、熱力發電機。
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會產生一個微弱的磁場。大多數物體中電子無 規律旋轉,因而它們產生的磁力相互抵消。而磁體有所不同。磁體內部的分子排 布使其電子朝一個方向旋轉。這種排布和運動產生了由北極指向南極的磁力。這 種磁力在磁體周圍形成磁場。
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磁場可以用來發電
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發電。移動磁場可以吸引和排斥電子。像銅這樣的金屬,其對電子的束縛力很弱,所以當磁體移動,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.
當運動的磁體和銅導線共同作用時,發電機就產生了電能。發電機的本質是 把動能轉換成了電能。