When process plants operate steam boilers for generating steam, they ensure that the combustion process is performed with optimal fuel consumption and steam production. It is a fact that combustion is pivotal in generating steam, with operating personnel endeavoring for as proper and optimum combustion process as possible. The combustion process requires a precise amount of fuel, oxygen, and ignition for the desired results. The steam boiler should be tuned with the proper air/fuel mixture for attaining optimum efficiency. Excess amount of oxygen in steam boilers results in reducing the boiler efficiency. However, excess fuel in the steam boiler can lead to severe failure.
Combustion Process in Steam Boilers:
The combustion process in steam boilers includes three stages, i.e., pre-heating, actual ignition, and post-combustion. A steam boiler burner system consists of air shutters to control the amount of air mixed with natural gas for proper burning. When air intake is controlled properly, it makes an impact if the fuel is wasted or the energy efficiency is increased by enhanced boiler combustion optimization.
Combustion Optimization in Steam Boilers:
With the advancement in combustion optimization technologies and procedures, there has been a significant increase in the boiler efficiency. It is essential to note that steam boiler burners need tuning in a compatible manner with the steam boiler system and design. There are various types of steam boiler systems and designs available in the market, but boiler burners require adjustment to operate properly within their particular boiler system or design type. Steam boilers need balancing for the air-to-fuel ratio to optimize fuel consumption and to provide maximum heat output at all times. If furnace components like nozzles, pilot assemblies, gas valves, etc., are out of working order, it may lead to steam boiler performance problems.
Importance of Boiler Tuning:
Steam boiler combustion is an integral function, necessary for generating steam and heat. Therefore, a boiler requires to be inspected at least annually by a qualified boiler service technician or engineer. The regular tune-ups of the steam boiler ensure that the system will continue to operate safely and efficiently. During this process, it is crucial to pay close attention to the boiler firing rate that can be adjusted using regulator settings on the motorized gas valve. The boiler combustion is deemed optimal as long it can allow air into the burner flame. If the airflow gets blocked, it leads to blocking of proper combustion and heat generation. Regular boiler combustion tuning should be considered as the topmost priority for preventing any hazardous problems such as carbon monoxide poisoning and air pollution.
Problems in Steam Boiler Combustion Tuning:
When the boiler combustion tuning problems remain unresolved by technicians, it can lead to boiler system breakdowns. Forced air gas or oil furnaces are the most common boiler burners that require tuning. It needs tuning if the input coal is of an inappropriate size or the air intake of the boiler is too high for its design. If the steam boiler is releasing a lot of sparks, then the cause may be low boiler airflow. Low airflow is caused due to the oversized burners on the boiler with high excess air. A boiler technician will be able to determine whether or not the boiler furnace needs tuning so that it operates properly and provides maximum heat output.
For the steam boiler to operate properly and produce maximum heat from the fuel, its combustion requires it to be balanced and have an optimum output. Negligence in the tuning of a boiler’s burner will result in generating low heat output and an excessive amount of fumes. It would cause a significantly excessive expenditure by using more fuel than necessary.
Tips to Increase the Boiler Efficiency:
- Seasonal tune-up:
It is recommended to tune the burner during the spring and again in the fall because of the difference in the air temperature and density changes that take place during these seasons.
- Tune the boiler when it is hot:
A cold boiler tends to discard the actual operating O2 and CO readings.
- Parallel positioning systems:
Parallel positioning systems along with integrated flame management allow outdated technologies to be efficient as they can be.
- Periodically monitor flue gas composition:
Regular monitoring and tuning of the boilers are necessary to maintain excess air at optimal levels. Online monitoring of the flue gas oxygen level quickly detects the energy loss patterns that can offer early warning of control failures and data to help in the decision making.
- Utilizing a pre-mix technology:
The technology achieves an 85% fuel/air premix, making the adjustments easier. Premix technologies also allow the boiler to achieve and maintain a 3% oxygen output that improves turndown ratios. As a result, steam is generated more quickly with significant fuel savings.
Conclusion:
Since its inception in 1983, Rakhoh Boilers has been providing industrial steam boilers and thermal solutions of world-class quality in over 26 countries worldwide.
Learn more about our products and services by visiting www.rakhoh.com