Increasing Efficiency and Heat Recovery in a Boiler System

As boilers age, they become less efficient. But there are many ways a facility can
increase boiler efficiency and reduce operating costs.

Take a look at these primary methods available and if you have any questions about your specific facility, contact one of our offices.

Keep up with Annual Boiler Maintenance
Maintaining a boiler according to manufacturer recommendations is the simplest way to ensure it will continue to run efficiently.

Proper Water Treatment
Check that the boiler system water is treated properly. Particulates clog up internal boiler tubes, and over time the system loses its heat transfer ability. In most applications, a deaerator is a good
solution. It can increase the water temperature to 227° F and remove a lot of the particulates from the water.

Install a High-Turndown Burner
Increasing the burner turndown rate will increase energy savings and reduce maintenance. Energy savings increases when on-off cycles are reduced. Each on-off cycle is followed by a purge
cycle. During a purge cycle, a large volume of air passes through the boiler, resulting in heat being blown out of the stack. Installing a high-turndown burner enables a boiler to consistently run at its most efficient point.

Add VSD Controls
Installing variable speed drives (VSDs) on boiler feed or deaerator pumps allows an operator to fine-tune the system to run at optimal conditions, while saving energy. This is because VSDs enable a motor to operate only at the speed needed at a given moment.

Incorporate Parallel Positioning
Adding parallel positioning to a boiler enables it to run at its most capable efficiency point. Parallel positioning uses dedicated actuators for the fuel and air valves. Burners that incorporate parallel positioning are able to maintain excess air levels more precisely.

Include O2 Trim
Another way to maintain peak efficiency is to add an oxygen sensor/transmitter in the exhaust gas. The sensor/transmitter continuously senses oxygen content and provides a signal to the controller that trims the air damper and/or fuel valve, maintaining the originally commissioned oxygen concentration under varying conditions. This minimizes excess air while optimizing the air-to-fuel ratio.

Integrate Lead/Lag
Lead/lag sequences the operation of multiple boilers, matching system load. Lead/lag enables boilers to operate in sync with fluctuating steam loads, reducing the possibility of process failure and needless boiler cycling.

Incorporate Heat Recovery
Another way to improve energy efficiency is to incorporate heat recovery into a boiler system. Several options are listed below. The right type of equipment for a boiler system depends on several factors, including: boiler type, fuel used, stack materials, and operating
conditions.

Contact an Office Near You
Find out what you can do to increase efficiency, minimize downtime and accomplish specific goals you may have for your facility equipment.
R.F. MacDonald Co. offers scheduled boiler inspection, maintenance and service to fit your specific facility needs. For more information call an R.F. MacDonald Co. office near you.

 

This Boiler Information Tip was provided by Cleaver-Brooks
as a part of their Boiler Basics Resource Center