www . refrigerationandaircon . co . za RACA Journal I November 2024 23
Feature
HEAT EXCHANGERS ADAPT TO MODERN DEMANDS
By Eamonn Ryan
Heat exchangers have evolved significantly to meet the growing demands for energy efficiency and integrated building services .
These devices , which include cooling towers , condensing units , thermal storage systems , and air handling units , are now pivotal in harnessing and redirecting energy from various sources .
In recent years , heat exchangers have become integral in capturing and repurposing previously wasted energy . Initially , these systems were used primarily to enhance water storage for domestic purposes or cleaning tasks , utilising what was once considered ‘ waste heat ’. However , their applications have expanded dramatically , now supporting advanced technologies and innovative solutions .
UNDERSTANDING HEAT EXCHANGERS At their core , heat exchangers are devices designed to transfer heat between two or more fluids . They are used in a variety of industries , including energy , chemical processing , HVAC , transportation , electronics , and refrigeration . The complexity of heat exchanger design extends beyond mere heat transfer analysis . Factors such as fabrication and installation costs , material selection , weight and size are crucial in determining the final design . In today ’ s compact plant environments , footprint considerations are often paramount .
Historically , rudimentary heat exchanging devices can be traced back to Roman baths , where systems known as ‘ recuperators ’ were used . By the turn of the first millennium , indirect heat exchange principles were applied in alcohol production , laying the groundwork for modern heat exchanger technologies . The formal development of heat exchangers began in the 1880s , with early applications in the food and beverage industry . The first patent for a plate heat exchanger was granted in 1878 , but commercial applications did not emerge until the early 1900s , with tubular heat exchangers being developed for power plants .
TECHNOLOGICAL ADVANCEMENTS From the late 19th to early 20th centuries , heat exchanger technology progressed rapidly , particularly with plate heat exchangers , which saw numerous patents and innovations , especially in milk pasteurisation . Over the decades , materials evolved to withstand corrosive media , and advancements in
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An example of the various forms of heat exchangers – cooling tower , condensing units and air handling unit .
A plate heat exchanger installed at a manufacturing facility .
viscous flow understanding led to new applications in the oil and gas industry .
Modern heat exchangers are now versatile , catering to everything from simple scenarios to complex industrial systems . Innovations such as magnetic technology that adjusts flow dynamics within micro-channel forms have emerged from research in the US and UK . For instance , during the COVID-19 pandemic , South African engineers developed a novel heat
www . refrigerationandaircon . co . za RACA Journal I November 2024 23