Heat Exchangers: Uses and Applications

Overview

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Heat transfer is one of the most important industrial processes. In any industrial facility, heat must be efficiently added, removed or moved from one process stream to another. A heat exchanger is a device designed to efficiently transfer or "exchange" heat from one matter to another. When a fluid is used to transfer heat, the fluid could be a liquid, such as water or oil, or could be moving air.

Heat exchangers can take many forms but, in all cases, the heat exchanger is presented with two fluid streams operating at different temperatures; the fluids are physically separated, the separation boundary also acts as a heat exchange surface. The separation boundary usually consists of bundles of tubes through which one of the fluids flows. Sometimes finned tubes are used. The separation may also take the form of plates between which a fluid flows.

Heat Exchangers are highly cost effective and help reduce the running costs by increasing the entropy of the overall process and in the following ways:

Heat Exchangers minimize the heat lost to the atmosphere by recovering some of the heat contained in process discharge streams. This energy can be fed back into the process or used to heat or cool the incoming fluid stream according to the process.

In power plants, Heat Exchangers (discharge condensers) can help in increasing efficiency of the turbine by reducing the discharge pressure as well saving process water requirement by redirected the condensate to the steam turbine.

In areas where it is difficult and expensive to get cooling water, air cooled heat exchangers provide a very efficient and robust solution for heat removal. Heat Exchangers can help in creating closed system loop for seal fluids used in vacuum pumps, rotary oil pumps and other vacuum generating equipment, thus creating stand alone vacuum equipment.