Heat Exchanger
A heat exchanger is a device that transfers thermal energy between two or more fluids at different temperatures without mixing them, usually across a metal wall. Main types are shell-and-tube, plate (gasketed, brazed or welded), air-cooled (fin-fan), double-pipe and plate-fin exchangers. Applications include process heating and cooling, lube-oil and hydraulic-oil cooling, condensers, reboilers and HVAC systems. Sizing is based on heat duty, fluid properties, inlet and outlet temperatures, allowable pressure drop, fouling factors and the log-mean temperature difference. Material selection depends on corrosion, pressure and temperature. Shell-and-tube exchangers are commonly built to TEMA standards and API 660, air-cooled exchangers to API 661 and plate exchangers to API 662, with pressure parts designed to codes such as ASME Section VIII.
Examples
- Shell-and-tube cooler for compressor lube oil
- Gasketed plate exchanger for HVAC water
- Air-cooled exchanger for process gas cooling