There are a number of ways to increase industrial boiler efficiency that can be implemented relatively easily. Most of the options enumerated below do not require any process or site modification and many of the changes can be combined for additional efficiency. The effectiveness of these changes will always vary according to the site where they’re implemented.
1. Replacement Boiler Burners
Over time, boiler burners begin to deteriorate and lose efficiency. At a certain point, it makes sense to replace or retrofit them. Whatever type of boiler you have or fuel you burn, there are many burner options to consider when contemplating a replacement. If you aren’t in a position to opt for new boiler burners, retrofits can provide significant savings at a fraction of the cost.
2. Air Preheaters
Air preheaters recover waste heat from flue gas and then use it to preheat combustion air. There are two main types of preheaters: recuperators and regenerators. A recuperator system is installed in a boiler stack and transfers heat from outgoing gas to incoming air. A regenerator, on the other hand, includes heat storage sections that transfer heat from flue gas to combustion air.
3. Boiler Economizers
Much like preheaters, boiler economizers take waste heat and transfer it to a boiler’s feedwater, rather than combustion air. Preheated water is obviously closer to the temperature needed to produce steam, so this saves energy when the preheated feedwater enters the steam drum or furnace. Economizers also offer the added benefit of reducing the chance of thermal shock by minimizing water temperature fluctuations.
Turbulators are only used in fire tube boilers. Simple baffles, blades, or coiled wires, turbulators are inserted into a fire tube boilers’ tubes to increase the turbulence of the gas in the tubes. This promotes more efficient heat transfer by maintaining a turbulent flow throughout boiler passes. Turbulators are usually installed in the last boiler pass and are an extremely cost-effective efficiency upgrade for older fire tube boilers.
5. Boiler Insulation
It seems obvious, but industrial boilers need to be insulated to minimize heat loss. Because industrial boilers are so big, they have massive surface areas that are vulnerable to significant heat loss if not insulated properly. The primary type of insulation used for industrial boilers is the refractory material that lines them. When replacing refractory materials, make sure to do a structural analysis to determine how much weight your boiler can support.
6. Air Infiltration Reduction
Air infiltration in industrial boiler systems can cause negative pressure in your furnace, leading to “stack effect” or “thermal head.” Unfortunately, air leaks can occur in numerous places throughout the entire boiler system — doors that are no longer sealed properly, cracks in the boiler casing, or deteriorating ductwork, for example. If you suspect your system is experiencing leaks, the best thing to do is to have it analyzed so that you can locate sites where air infiltration is occurring. Then prioritize repairs accordingly.
7. Blowdown Heat Exchangers
Blowdown is a simple fact of boiler operation. Sadly, it means ejecting hot water from the boiler, which wastes energy. Installing a blowdown heat exchanger, flash tank, or combination of the two can help recover some of this energy for your boiler system. Cooling blowdown through heat recovery can also be a good idea because it avoids releasing extremely hot liquids into the sewer system.
8. Condensate Return Systems
Boiler condensate is essentially hot water, which is what you need to run your boiler. Not recovering it for your industrial boiler system is a waste of energy. A return condensate system can help you recoup condensate’s heat and water, but it has to be carefully matched to your boiler system to guarantee condensate quality. Many modern boilers already include condensate return systems.
9. Soot Blowers
Byproducts of combustion such as soot and ash inevitably build up on heat transfer surfaces in a boiler, even if it is run flawlessly within operating parameters. Installing an intelligent soot blowing system (ISS) can keep this buildup in check with periodic jets of compressed air or steam triggered by undesirable conditions. Of course, soot blowing and deslagging can also be performed manually.
10. Regular Maintenance
The best way to keep your industrial boiler system running efficiently is to have a regular boiler maintenance program. While all of the suggestions above can make a significant difference if implemented correctly, they also involve installing or replacing equipment. And with more equipment comes more chances for malfunctions. A good maintenance program will slow equipment deterioration, enhance efficiency, maintain reliability, and ultimately reduce operating costs.
source - wikipedia, national boiler