संरक्षण युक्तियाँ

THERMAL UTILITIES

Boilers

• Preheat combustion air with waste heat
• (22 oc reduction in flue gas temperature increases boiler efficiency by 1%).
• Use variable speed drives on large boiler combustion air fans with variable flows.
• Burn wastes if permitted.
• Insulate exposed heated oil tanks.
• Clean burners, nozzles, strainers, etc.
• Inspect oil heaters for proper oil temperature.
• Close burner air and/or stack dampers when the burner is off to minimize heat loss up the stack.
• Improve oxygen trim control (e.g. -- limit excess air to less than 10% on clean fuels). (5% reduction in excess air increases boiler efficiency by 1% or: 1% reduction of residual oxygen in stack gas increases boiler efficiency by 1%.)
• Automate/optimize boiler blowdown. Recover boiler blowdown heat.
• Use boiler blowdown to help warm the back-up boiler.
• Optimize deaerator venting.
• Inspect door gaskets.
• Inspect for scale and sediment on the water side
• (A 1 mm thick scale (deposit) on the water side could increase fuel consumption by 5 to 8%).
• Inspect for soot, flyash, and slag on the fire side (A 3 mm thick soot deposition on the heat transfer surface can cause an increase in fuel consumption to the tune of 2.5%.)
• Optimize boiler water treatment.
• Add an economizer to preheat boiler feedwater using exhaust heat.
• Recycle steam condensate.
• Study part-load characteristics and cycling costs to determine the most-efficient mode for operating multiple boilers.
• Consider multiple or modular boiler units instead of one or two large boilers.
• Establish a boiler efficiency-maintenance program. Start with an energy audit and follow-up, then make a boiler efficiency-maintenance program a part of your continuous energy management program.

Steam System 

•  Fix steam leaks and condensate leaks (A 3 mm diameter hole on a pipe line carrying 7 kg/cm2 steam would waste 33 kilo litres of fuel oil per year).
• Accumulate work orders for repair of steam leaks that can't be fixed during the heating season due to system shutdown requirements. Tag each such leak with a durable tag with a good description.
• Use back pressure steam turbines to produce lower steam pressures.
• Use more-efficient steam desuperheating methods. 
• Ensure process temperatures are correctly controlled.
• Maintain lowest acceptable process steam pressures.
• Reduce hot water wastage to drain.
• Remove or blank off all redundant steam piping.
• Ensure condensate is returned or re-used in the process(6 0C raise in feed water temperature by economiser/condensate recovery
• corresponds to a 1% saving in fuel consumption, in boiler).
• Preheat boiler feed-water.
• Recover boiler blowdown.
• Check operation of steam traps.
• Remove air from indirect steam using equipment (0.25 mm thick air film offers the same resistance to heat transfer as a 330 mm thick copper wall.)
• Inspect steam traps regularly and repair malfunctioning traps promptly.
• Consider recovery of vent steam (e.g. -- on large flash tanks).
• Use waste steam for water heating.
• Use an absorption chiller to condense exhaust steam before returning the condensate to the boiler.
• Use electric pumps instead of steam ejectors when cost benefits permit
• Establish a steam efficiency-maintenance program. Start with an energy audit and follow-up, then make a steam efficiency-maintenance program a part of your continuous energy management program.