Heat exchangers are devices built for efficient heat transfer from one fluid to another and are widely used in engineering processes. Some examples are intercoolers, preheaters, boilers and condensers in power plants. By applying the first law of thermodynamics to a heat exchanger working at steady-state condition, we obtain:

mi hi=0

where,
mi= mass flow of the i-th fluid
hi= change of specific enthalpy of the i-th fluid

There are several types of heat exchanger:

• recuperative type, in which fluids exchange heat on either side of a dividing wall
• regenerative type, in which hot and cold fluids occupy the same space containing a matrix of material that works alternatively as a sink or source for heat flow
• evaporative type, such as cooling tower in which a liquid is cooled evaporatively in the same space as coolant.

Back