43.High School English Listening

When you think of something boiling, you probably picture a pot on the stove,
but there'sanother kitchen appliance that brings liquid to a boil, not to heat food, but cool it.
It sounds crazy,but household refrigerators keep food cold by bringing liquid fluorocarbon to a boil.
How Does This Work?
Fluorocarbon coolant flows through two sets of coils in your fridge, absorbing heat inside andreleasing it outside, into your kitchen.
You've probably seen one set of coils behind the fridge, in back.
That's where heat's released.
Hidden inside the fridge is the other set of coils, where heat'sabsorbed.
It's inside these hidden coils that liquid coolant comes to a boil.
What makes the coolant boil?
The secret is in the relationship between pressure and boiling point.
When pressure changes, so does the temperature at which a substance comes to a boil.
As the liquid coolant passes through a valve into the hidden coils, the pressure drops.
This pressure change makes the coolant's boiling point drop below the chilly temperature in the fridge.
So, some of the coolant boils immediately and evaporates into a gas inside the coil.
Evaporation uses up lots of heat energy.
As the coolant continues to boil and evaporate, it absorbs heat fromthe air in the fridge, making it even colder inside.
So that's how boiling fluorocarbon cools your food.
译文：
当你想到东西沸腾时，你可能会想到炉子上的一个锅。
但是，还有一种厨房设备将液体煮沸，不是为了加热食物，而是为了冷却食物。
这听起来很疯狂，但家用冰箱通过将液体氟碳化物煮沸来保持食物的温度。
它是如何工作的？
氟碳化合物冷却剂流经冰箱中的两组线圈，在内部吸收热量，并将其释放到外面，进入你的厨房。
你可能已经看到冰箱后面的一组线圈，在后面。
那是释放热量的地方。
隐藏在冰箱里面的是另一组线圈，是吸收热量的地方。
正是在这些隐藏的线圈内，液体冷却剂开始沸腾。
是什么让冷却剂沸腾？
秘密在于压力和沸点之间的关系。
当压力发生变化时，物质沸腾的温度也会发生变化。
当液体冷却剂通过一个阀门进入隐藏的线圈时，压力下降。
这种压力变化使冷却剂的沸点下降到冰箱里的寒冷温度以下。
因此，一些冷却剂立即沸腾，在线圈内蒸发成气体。
蒸发会消耗大量的热能。
随着冷却剂继续沸腾和蒸发，它从冰箱内的空气中吸收热量，使冰箱内更加寒冷。
因此，这就是沸腾的氟碳化合物如何冷却你的食物。
重点词汇：
think of 想想 ; 想起
cool it 冷静下来;别激动
fluorocarbon 碳氟化合物
've (=value engineering)价值工程学 ; 同“have”
in back 在后面；在后舱，在尾部
set of 的 ; 集合 ; 释……的集合
liquid coolant 冷却液；液体冷却剂