As boilers get older, they also become less efficient and more prone to repair and maintenance. While replacing old boilers seems like an obvious choice, it is not always necessary. If the pressure level of the boiler is still in good condition, a controls and burner update can restore the machine to its efficient state.
To improve the efficiency of your industrial boilers, consider these suggested upgrades.
Set-up a High-Efficiency Burner
If your boiler has been in service for more than 15 to 20 years, the burner can lose its effectiveness. This is bound to happen regardless if you regularly maintain it. Cams, linkage joints, and other parts can also wear out. This wearing can lead to a decrease in the burner’s ability to control its air-to-fuel ratio.
All of these will result in hysteresis, or the burner’s inability to keep the ideal level of excess-air in the firing range. The burner will adjust to accommodate higher levels of excess air to keep the air-to-fuel ratio within a safe range.
Unfortunately, increased levels of excess air can result in diminished combustion efficiency. Adding insult to injury, the burner can also manifest other issues like combustion head parts deterioration, gas orifice, and nozzle erosion, and so on.
Later on, these issues can lead to reduced overall efficacy and increased operating costs.
It is wise to replace your burner with a new one that features a better turndown capacity. Older burners have narrow turndown ranges. New burners with high turndown capacity, on the other hand, can run at lower firing ranges, thereby significantly cutting down expenses and cycling occurrences.
Install New Controls
A modulating motor operates most industrial boilers with a single drive that controls fuel and air. This process is done through a motorized jackshaft with connected linkages, arms, and cams. Adjusting each of these components can efficiently adjust air and fuel. The ratio for each firing rate is set, too.
The only problem here is that the system cannot stay in place because of modulation. As a result, arms and joints wear out. This will again result in hysteresis, which later on leads to poor control of air to fuel ratio.
To remedy this problem, replace the jackshaft with parallel positioning. The latter utilizes a motorized actuator to electrically tie air and fuel valves into the boiler’s electronic firing-rate controller. The motorized actuator can control the entire boiler’s firing range. With such a mechanism in place, hysteresis and slip are both prevented.
Add Heat Recovery
The last method to improve the boiler’s energy efficacy is by incorporating heat recovery into the boiler system. The right equipment for this will depend on factors such as operating conditions, stack materials, fuel used, and boiler type.
Standard economizers transfer energy to the feedwater from the boiler’s exhaust gas through sensible heat. The economizer captures this sensible heat and redirects it to the boiler stack from the hot flue gas chamber. This heat will then increase the boiler feedwater’s temperature. On average, an economizer can improve the boiler’s efficiency by over five percent.
As you can see, replacing your old boilers with a new one is not always the solution to boiler efficiency problems. Apart from improving your boiler’s efficacy these tips can also help you save money. To help you save money further, make sure to maintain your boiler system regularly. Also, it would not hurt if you conduct a routine energy audit now and then. After all, prevention is always better than cure.