How to improve boiler efficiency? Boiler efficiency is a percentage that represents the amount of valuable energy transferred from the fuel into steam. For example, a boiler with an efficiency of 90 percent would share 90 percent of its input heat into mist, losing 10 percent as waste heat.
Many factors may cause energy inefficiency in the boiler like low draft, decreased combustion airflow, over firing, fuel with poor quality (increasing the ash content), no water level in the boiler drum, operating at high pressure, etc. Here are some of the things you should consider.
Lower the Excess Air
Excess air is the amount of oxygen in the combustion chamber than the required burning of carbon monoxide and hydrogen. Lowering the excess air will reduce the temperature of flue gases, reducing heat losses from your boiler up to 25 percent. It is an excellent way to make your boiler more energy efficient.
Lower the Stack Temperature
Stack temperature is the temperature of the exhaust gas leaving your boiler. Lowering the stack temperature can reduce heat loss from your boiler up to 15 percent, making it more energy-efficient. The best way to keep the stack temperature low is by burning clean fuels with low ash content, proper combustion airflow, and a flue gas analyzer.
Regular Burner Tune-Up
When it comes to boiler efficiency, not getting the proper amount of air is another issue. If there is excess air, you have to deal with the lower stack temperature issue. An excellent way to deal with both problems at once is by performing a burner tune-up. It will not only improve boiler efficiency but also prolong the life of its components.
Installing an Economizer
An economizer is a heat exchanger that captures heat from the flue gases before leaving your boiler. The captured heat will preheat the combustion air that enters the burner. Using an economizer can increase your boiler efficiency by up to 5 percent while also decreasing fuel consumption and emissions since it maintains the equipment at the lower end of the oxygen curve, which leads to complete combustion.
Installing a VFD
Variable Frequency Drive (VFD) is a device that controls the speed of an electric motor. It offers more control over the steam generation process, which results in improved fuel economy and boiler efficiency. VFD can also provide better temperature control and automatic boiler tunings to maintain optimum conditions for your equipment.
Enhance the Boiler Insulation
Poor insulation is another common factor that results in a lot of heat loss. Insulating your boiler can help you save money by reducing fuel consumption and maintenance costs. If the temperature outside your factory decreases, your boiler will have to work hard to maintain its steam production levels. It might increase fuel consumption, which you don’t want.
Improve Boiler Controls
Boiler controls play a significant role in the overall efficiency of your boiler. By enhancing their features, you can improve your boiler efficiency. For example, installing a flow transmitter on the water supply line will automatically control the feed valve and optimize steam output. Automated combustion control offers a greater level of safety, plus it’s easier to use.
Insulate the Valves
Exposed valves waste heat and increase the temperature of flue gases, which in turn decreases boiler efficiency. Exposing massive valves to the air may lead to corrosion and heat loss. If you want to maintain the efficiency of your boiler, make sure that all valves are adequately insulated.
Bleed Your Radiators
The system will lose 1lb steam for every 33lb of steam you produce if not used for heating purposes. The best way to minimize this waste is by bleeding your system. This process removes all the air in the radiators, ensuring that only high-quality steam enters them. By bleeding all the air out of your radiators, you’ll not only save energy but also reduce corrosion.
Clean the Fireside Boiler Tubes
Fireside boiler tubes have a significant impact on the overall efficiency of your boiler. They get dirty from time to time and need proper cleaning to work at their best. By using a safe, efficient, and effective way to clean your boiler tubes, you’ll get lower emissions, increased fuel economy, improved combustion quality, and more boiler efficiency.
Clean the Waterside Boiler Tubes
When water tubes get dirty, several problems arise. The most common one is the decrease in boiler efficiency by up to 2 percent. Make sure to clean mud drums or mud legs regularly to prevent rusting and scaling and ensure excellent heat transfer from the metal to the water.
Rust and Scale may accumulate around the outer surface of tube bundles which can cause problems in water flow inside the tubes. Also, when steam enters the dirty tube bundle, it will get covered with rust and scale particles. If you don’t remove these particles, they’ll block water flow through the inner walls of tubes.
As a result, not only your overall boiler efficiency will decrease, but also it will lower heat transfer in steam generator tubes. Also, when scaling occurs in the boiler water tube, it affects the heat transfer rate, which decreases the overall efficiency of your equipment.
Preheat the Combustion Air
Combustion air that’s too cold decreases the overall efficiency of the boiler because it increases fuel usage. An excellent way to prevent this is by preheating the air that enters your burner. It will maintain optimum temperatures, which in turn ensures low emissions and higher boiler efficiency. It will also improve combustion by as much as 5 percent and reduce emissions since there will be less unburned fuel in your equipment’s exhaust gases.
Reduce the Steam Usage
Steam is often considered the best and most effective way to transfer heat from one area of your factory to another. Still, your overall boiler efficiency will be lower if you aren’t using it correctly or creating excess steam and then releasing it into the atmosphere. Instead, make sure that you’re using all the steam produced by your equipment for intended purposes. For example, if you have a pressing machine and want to get rid of excess moisture, why not use it for heating instead of wasting it?
To produce high-quality steam, all of the processes that take place in a boiler must be perfect. Still, if you want to boost your equipment’s efficiency and produce more steam with less fuel, automated combustion control can be beneficial.
How to Improve Boiler Efficiency – Conclusion
Boiler efficiency is essential for every industry in the world. Still, to make sure that your boiler’s efficiency doesn’t decline over time, you must do routine equipment maintenance and use the right amount of steam at all times. This way, you’ll reduce the amount of wasted steam and boost your equipment’s overall efficiency.