How Does A Heat Exchanger Work?


Tank coil heaters

How do you properly maintain your air cooled heat exchanger? What’s the difference between heat transfer coils and fuel oil heaters? If you don’t know your equipment, you won’t know your results. This uncertainty can cost you not just your business, but your customers’ good faith down the line. Rather than leave your luck to chance, learn about the mixture of science and technology that goes into the average air cooled heat exchanger, pressure vessel and after cooler. You’ll be glad you did.

Let’s launch straight into the basics. What kind of heat exchangers are there? You’ll generally find three types. You have your parallel-flow (also known as counterflow configuration), your cross-flow configuration and your shell-and-tube configuration. Your air cooled heat exchanger will use a combination of horizontal and vertical configurations to ensure the smoothest transfer possible.

It’s never been better to be knowledgeable about heat exchanger design. The year 2013 saw the revenue of both boiler and heat exchanger manufacturing in the United States reaching an impressive $7 billion. The heat exchanger market is also expected to rise beyond even those alarming figures ant hit $19 billion by the time 2021 comes around. That’s over 8% CAGR. But what else should you know before you make the plunge?

The function of a heat exchanger is to transfer heat between two or more fluids. It is also used to transfer between a solid surface and a fluid or between solid particulates and a fluid, no matter the different temperatures or thermal contact. The close proximity of these different process fluids within the heat exchanger is what creates the exceptionally high heat transfer that creates the products people rely on every day.

These are delicate devices, however, and a lot can go wrong. For the proper heat transfer to properly occur between both of the fluids they must maintain different temperatures and come from thermal contact only. The heat exchange involves each fluid and conduction going through the separating wall. As per the second law of thermodynamics, heat can only flow from hotter to colder fluids. Not the other way around.

When it comes to parallel flow heat exchangers, however, there are a few key differences. Both the tube side fluid as well as the shell side fluid need to flow in the same direction. Cross flow heat exchangers, as well, have their own unique details. One fluid will flow through tubes, while the second will pass through perpendicularly. From hot water storage tanks to an air cooled heat exchanger for energy storage, knowing is most of the battle.

Maintenance must be ongoing to ensure the long-term suitability of the product. The shell portion of a heat exchanger can last as long as 40 years without corrosion, though that doesn’t mean regularly check-ups are out of the question. A little goes a long way, after all, and this wisdom is just as astute as any law rooted in physics.