Energy Efficient Steam SystemsSteam SystemsSteam systems most widely used type of process heatingAdvantages of steam:Heat carrying capacity of steam much greater than air or waterSteam provides its own locomotive forceSteam provides heat at a constant temperaturelb/hr to deliver 1 mmBtu/hr of heatSteam SystemSteam SystemEnergy FlowsEnergy enters a steam system as:Fuel and combustion airMakeup waterPump workEnergy leaves a steam system as:Heat to the processEhaust air!lowdown"ondensate lossFlash vaporHeat loss from the boiler# steam pipes# condensate pipes and deaerator tank$Fuel %se &educedFuel use reduced by reducing:Heat to the processHeat in ehaust air!lowdown"ondensate lossFlash vaporHeat loss from the boiler# steam pipes# condensate pipes and deaerator tank$Energy Saving 'pportunities() &educe Steam *emand+nsulate hot surfaces"over uninsulated tanks,) Fi Steam -rapsSteam traps are automatic valves that discharge condensate from a steam line without discharging steam$ +f the trap fails open# steam escapes into the condensate return pipe without being utili.ed in the process$ +f trap fails closed# condensate fills the heat echanger and chokes/off heat to process$Fiing failed steam traps is highly cost/effective$ 0) +nsulate Pipes and -anks+nsulatesteam pipescondensate return pipescondensate return tanksdeaerator tankvalves1) Preheat !oiler Feed/water %sing Ehaust AirEconomi.er is heat echanger that preheats feed/water to the boiler using heat from the ehaust gasses$Economi.ers are most cost effective in process boilers that operate all year$ 2) Minimi.e Steam Pressure3enerating steam at ecess pressure:decreases boiler efficiencyincreases heat lossincreases flash loss$&educing boiler pressure to match the highest re4uired process temperature decreases these losses$ &educing steam pressure to match local re4uired process temperature reduces flash loss$ -hus# always produce and supply steam at the minimum pressure re4uired to meet the process temperature re4uirement$ 5) +nstall Automatic !low *own "ontrols!low down is the practice of epelling steam to reduce contaminant build ups$ -ypical blowdown rates range from 16 to 76 of boiler feed/water$ Manual blowdown relies on intuition or periodic testing$Always results in ecess blow down that wastes energy or insufficient blow down that creates ecess scale on heat transfer surfaces and reduces efficiency$Automatic blow down reduces energy# water and water treatment costs$%nderstanding "ombustionStoichiometric Combustion Air: No Safety MarginCH4 + 2 (O2 + 3. N2!

CO2 + 2 H2O + ".# N2$%& '(cess Combustion Air:Correct Safety MarginCH4 + 2.2 (O2 + 3. N2! CO2 + 2 H2O + .4 N2 + %.4 O2$%%& '(cess Combustion Air: )oo Much AirCH4 + 4 (O2 + 3. N2! CO2 + 2 H2O + $*.2 N2 + 2 O2%nderstanding "ombustion Efficiency Efficiency highest at 8'9 E:"ESS A+& and 8'9 S-A"; -EMPE&-%&ESS-A"; -EMPE&A-%&E increases with F+&+