Phase-change Heat Exchangers

Generally heat exchangers can be applied either to heat a liquid to dissolve it or utilized as condensers to cool a vapor and condense it to a liquid. In chemical plaints refineries, re-boilers used to heat incoming feed for distillation towers are frequently heat exchangers. Distillation set-ups typically utilize condensers to compress distillate vapors back into liquid. Power plants that have steam-driven turbines generally use heat exchangers to boil water into stream. Heat exchangers or analogous units for producing steam from water are referred as boilers or steam generators.

Steam driven turbines in use

The pressurized water reactors in the nuclear power plants are especially large phase-change heat exchangers that pass heat from the initial system to the secondary system, producing steam from water in the process are known as steam generators. All fossil-fueled and nuclear power plants using steam driven turbines have surface condensers to convert the exhaust steam from the turbines into condensate water for reuse.

To conserve energy and cooling ability

In order to conserve energy and cooling ability in chemical and other plants, phase-change heat exchangers can be used to transfer heat from one stream that requires to be cooled to another stream to be heated like distillate cooling and re-boiler feed preheating. This term can also refer to heat exchangers that include a material inside their structure that has a change of phase. Generally, this is a solid to liquid phase because of the small volume difference between these states. This particular variance of phase effectively works as a buffer since it happens at a regular temperature yet permits for the heat exchanger to accept additional heat.

Extraordinary exchangers

Further to heating up or cooling down fluids in a lone phase, heat exchangers are utilized to heat a liquid to evaporate it or used as condensers to cool a vapor and condense it to a liquid. In chemical plants and refineries, re-boilers used to heat inward bound feed for distillation towers are regularly heat exchangers. In the nuclear power plants known as pressurized water reactors, extraordinary large heat exchangers which move heat from the initial system to the secondary system, making steam from water in the course are known as steam generators.

All fossil-fueled and nuclear power plants using steam-driven turbines have surface condensers to convert the exhaust steam from the turbines into condensate for re-use. Power plants that have steam-driven turbines generally use heat exchangers to boil water into steam. Phase-change heat exchangers for making steam from water are frequently called as boilers and steam generators.

Questions:

• What are phase-change heat exchangers?
• List the advantages of phase-change heat exchangers.