Instrumentation is vital to prove the efficiency of the boiler. Owners and operators should have the following instruments as part of their maintenance system for monitoring proper boiler performance and optimizing steam and combustion system efficiency:
 

• Gas flow meter (if burning gas) – multi-variable (pressure, temperature compensated). This could be a differential pressure (orifice plate - this is a good element but could create too much pressure loss), (Anaubar – this too is a good element and has less effect on the pressure loss). Vortex – make sure it is pressure and temperature compensated, insertion style recommended.

• Oil flow meter (if burning oil) – Emerson Coriolis flow meter (Viscosity and Density) or the Trimec positive displacement meter.

• Steam flow meter – multi-variable (pressure, temperature compensated). This could be a differential pressure (orifice plate - this is a good element but could create too much pressure loss), (Anaubar – this too is a good element and has less effect on the pressure loss). Vortex – make sure it is pressure and temperature compensated, insertion style recommended.

• Water flow meter – (optional) multi-variable (pressure, temperature compensated). This could be a differential pressure (orifice plate - this is a good element but could create too much pressure loss), (Anaubar – this too is a good element and has less effect on the pressure loss). Vortex – make sure it is pressure and temperature compensated, insertion style recommended.

• • Note: A great thing about multi-variable meters is that you have three to five instruments in one: Process Pressure, Element Differential Pressure, Absolute Pressure at that location, Process Temperature, and Real time Calculated Mass flow output from all extra instruments. It has on board processor and increasing element turn down and performance. The other primary elements can also be read via analog inputs with the right required components.
• Stack temperature measuring device – this could be a RTD (Resistance Temperature Device) or T/C Thermocouple Transmitter. This temperature could be used to indicate fouled water and firesides, or a low water conditions problem. The higher the O2% level, the higher the stack temperature will be. The closer you can get the stack temperature to steam saturated temperature means the boiler is performing at its best.

• O2 analyzer – including stack mounted Insitu O2 analyzer or a portable unit. Small analyzers include Testo and UEI. These are good instruments used for routine checks, and will give a read out in O2%, CO PPM, and stack and ambient temperature.

• Chart recorders – this is a great instrument for collecting data and finding problems with trending. Recommend a paperless chart recorder with SD card and math function.

With these instruments in place you’ll be able to determine how efficient your boiler is preforming. You’ll also be able to pin point problems in the boiler or burner, or both. Boiler, burner and instrumentation technologies have improved vastly over the last few decades.

Burner modification can also increase system efficiency and performance. We have converted burners with high O2 (6 to 12%) and CO (1000 to 50,000 PPM) issues, for example, achieving combustion results of O2 1 - 3%, and CO as low as 1 - 100 PPM, that will perform from 4:1 to as high as 10:1. It’s also good idea to perform routine flame inspections.

An infrared gun (camera viewing style recommended) is worthy investment used to find hot spots on boilers, faulty steam traps, and steam leaks that are hard to see.

Other important boiler room equipment that impact system efficiency includes water softener, deaerated feed tank, chemicals, economizers, and blow down heat recovery systems.

With proper instrumentation and and control systems in place, efficiency can often be improved anywhere from 1% to 10% or more, and deliver 2% to 5% in savings.

In addition to internal monitoring and maintenance, it pays to have a knowledgeable boiler/burner partner with solid experience in combustion and service on an variety burners, boilers, and fuels and related equipment.