902. Furnace and Boiler Optimization and Energy Efficiency Tips
There are many economic and business related reasons for monitoring and controlling the furnace, to optimize it for best results. Economic reasons include environmental regulation of reducing NOx emissions, and environmental safety issues and personnel safety are always at the top of the priority list. In addition, there are business-related issues which motivate organizations to monitor and control the combustion area: increase fuel efficiency, reduce unnecessary shut downs because of tube or furnace damage, safety of personnel and equipment, and increased capacity.
- Check the combustion air inlet for proper sizing. Make sure that the air inlet is not blocked and that the supply of combustion air is sufficient.
- Check burner performance and make adjustments if needed. Clean burners to maintain efficiency and safety. Check fuel supply and the filter in the fuel supply line (applicable to oil systems only).
- Look for and remove any dirt, soot, or rust in the heat exchanger. The heat exchanger should be checked using a non-destructive method. Inspect for cracks, seam failure and warpage.
- Have your inspector perform a flue gas analysis and give you the results to keep for future reference. The results will help you determine the efficiency of your system.
- Reuse some of the waste heat from the boiler stack to pre-heat the combustion air, which increases boiler efficiency.
- Test all controls for proper operation. If possible, optimize on-off settings for energy efficiency.
- Oil the pump to allow smooth operation and prevent the motor from overheating.
- Remove dirt and grime from the pump to insure an efficient heat transfer.
- Bleed radiators by opening valves to release pockets of air. Once the water is flowing steadily, you’ll know that you have let all of the unwanted air escape.
- After radiators have been bled, check the temperature/pressure gauge(s) and maintain the boiler’s proper water level.
- Check the expansion tank to insure that it has proper air and water levels to allow room for expansion.
- Prevent scale accumulation in boiler tubes, which impedes flow and heat transfer, by properly maintaining water treatment systems. This also minimizes boiler blowdown. Potential efficiency gains of 10 percent – 12 percent.
- Inspect steam distribution systems. Leaks, faulty valves, faulty steam traps, etc. can be costly. Potential energy savings of up to five percent.
- Return steam condensate to the boiler plant.
- Use steam condensate for non-potable hot water supply or flash the condensate to produce low-pressure steam.
- Recover “dirty” (used) steam for reuse by using thermal or mechanical vapor recompression, for applications requiring higher steam pressure.
- Use minimum steam operating pressures.
- Reduce excess steam bleeding.
- Shut off steam traps on super-heated steam lines when not in use.
- Regularly cleaning strainers upstream of steam traps to prevent particle accumulation can yield efficiency gains of 10 percent – 15 percent.
- Insulating your pipes, valves, fittings, etc. can yield energy savings of two percent to five percent.
- Minimize surplus combustion air by adjusting fans, dampers, seals and optimizing over-fire draft controls. Reducing air and oxygen by 15 percent and 1.5 percent, respectively, can provide a one percent gain in efficiency.
- Lower the water temperature of boilers to reduce short-cycle, convective and radiant heat losses. A potential increase in efficiency of one percent is gained by reducing stack temperatures by 40F.