Soojusvaheale

Soojusvaheale (heat exchanger) is a device designed to transfer thermal energy between two or more fluids without mixing them. It is widely used to recover waste heat, preheat process streams, or enable temperature control in HVAC, refrigeration, chemical processing, and power generation. The basic function is to provide a large surface area for heat transfer under appropriate flow conditions, while maintaining a barrier between fluids.

The most common types are shell-and-tube, plate, fin-tube, and air-cooled heat exchangers. Shell-and-tube units consist of a bundle of tubes inside a larger shell; one fluid runs through the tubes while the other flows around them. Plate heat exchangers use corrugated plates that form many channels, offering high surface area in a compact volume. Fin-tube and air-cooled designs rely on extended surfaces and air flow to remove or supply heat, often used where water is scarce.

Performance is described by the overall heat transfer coefficient (U) and the heat transfer area. The driving force is the temperature difference between the fluids, and the arrangement (countercurrent, parallel flow, or crossflow) and flow rates determine the duty and efficiency. Materials are chosen for corrosion resistance, pressure rating, and compatibility with the process fluids.

Design considerations include minimizing pressure drop, preventing fouling, and facilitating maintenance. Common applications include condensers and boilers in power plants, HVAC systems, chemical processing, and refrigeration, where efficient heat exchange improves energy efficiency and process control.