In a heat exchanger heat is transferred from one (hotter) material or material flow to another (cooler) one. In most applications operated under steady-state conditions, for heat exchange between fluid flows. External walls are well insulated to avoid heat losses to the environment (except for most air cooling systems).
Designing a proper steam heat exchanger or steam heat tracing system first requires a full understanding of the operational characteristics where the system will function. Inadequate performance is most commonly attributed to a design engineer’s failure to consider all steam system characteristics. A thorough review should be conducted of the steam system’s operating parameters and documentation. Failing to understand the context of the application commonly results in inappropriate control or selection of system components.
Steam-to-Water or Water-to-Fluid heat exchangers are used primarily to heat a fluid in the tube bundle with steam or water. Proper installation of control valves, vacuum breakers and steam traps are essential for trouble-free operation of the system. Efficient operation of a heat exchanger requires extracting the maximum heat from the steam. This is accomplished by operating at the lowest possible heat source pressure, and sub-cooling the condensate (in case of steam) after it is drained through the steam trap to eliminate flash steam.