Intercoolers are appearing on every car and they seem to be getting bigger and shinier each time we see them. Here is just a quick run-down on what intercoolers do.
While an intercooler seems like a very simple device, they are actually an intricate bit of gear which can have a dramatic effect on the performance and reliability of your turbo set up. This little guide will by no means go into great detail in explaining the thermodynamics involved with an intercooler; that will be saved for the Inside Line devoted to automotive cooling. Instead we will offer a starting guide to understanding what an intercooler can do, how it is almost and essential part of a modern turbo set up, and how it will keep your intake charge colder than the Elephant man’s bed.
A turbocharger compresses air at a dramatic rate. At high engine speeds a turbo can compress air at up to 20 cubic metres a minute. Compressing air creates heat. Think of a hand air pump, after prolonged usage when pumping up a ball, or a bike tyre, it gets hot.
If you can recall back to year 7 science, you may remember that heat expands things and cooling causes them to contract. Intercooling involves passes the compressed air through a heat exchanger. This removes heat from the air, meaning that the air contracts to a smaller volume and more can be fed into the engine.
More air into the cylinders means more fuel can be burnt. This will then increase the amount of energy released and the engine's maximum power output will be increased greatly. The power increase will depend on the effectiveness of the heat exchanger as well as the length of the piping and the size of the intercooler. The bigger the intercooler the more surface area the intercooler has to transfer heat. But if the intercooler is too big and the piping is too long this will mean the turbocharger will have to work harder and there can also be a slight pressure loss, resulting in less power. The larger the heat exchanger, the more costly and heavier it gets also. When selecting a heat exchanger for intercooling, engineers need to seek a compromise between power, cost and weight.
This is just a bare bones explanation of what an intercooler does, and how it works. When we cover engine cooling in the future we will discuss more in depth issues revolving around the science of intercooling. Stay tuned.
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