STEAM PRESSURE REDUCTION, OPPORTUNITIES, AND ISSUES

摘要

Steam pressure reduction has the potential tornreduce fuel consumption for a minimum capitalrninvestment. When the pressure at the boiler isrnreduced, fuel and steam are saved as a result ofrnchanges in the high-pressure side of the steam systemrnfrom the boiler through the condensate return system.rnIn the boiler plant, losses from combustion,rnboiler blowdown, radiation, and steam venting fromrncondensate receivers would be reduced by reducingrnsteam pressure. Similarly, in the steam distributionrnsystem, losses from radiation, flash steam ventedrnfrom condensate receivers, and component and steamrntrap leakage would also be reduced. There arernpotential problems associated with steam pressurernreduction, however. These may include increasedrnboiler carryover, boiler water circulation problems inrnwatertube boilers, increased steam velocity in piping,rnloss of power in steam turbines, and issues withrnpressure reducing valves.rnThis paper is based a Steam Technical Briefrnsponsored by the U.S. Department of Energy (DOE)rnOffice of Energy Efficiency and Renewable Energyrnand Enbridge Gas Distribution, Inc. (5). An examplernillustrates the use of DOE BestPractices SteamrnSystem Assessment Tool to model changes in steam,rnfuel, electricity generation, and makeup water and tornestimate resulting economic benefits.