Combustion analyzers are multifunction instruments designed to calculate the efficiency of all types of boilers, heaters and furnaces by measuring a range of parameters such as stack
temperature, flue pressure and levels of gases. Combustion analysis is crucial for the proper operation and control of any combustion process. Through the analysis of combustion parameters,
it's possible to improve efficiency resulting in lower fuel costs, fewer pollutants being emitted, and lower expenses.
Combustion occurs when fuel, generally a fossil fuel, reacts with oxygen to produce heat. When combustion is harnessed to provide usable heat, the objective is to retrieve energy from the fuel
in the most efficient manner possible, meaning burning the fuel as completely as possible with the least amount of loss. Stoichiometric combustion is the theoretical point at which the fuel to
air ratio is ideal so that there is complete combustion with perfect efficiency, though, in reality this is unattainable.
Applications:
Combustion analyzers were developed with the goal of finding the ideal fuel to air ratio for each application so as to come as close as possible to complete combustion. Though anyone with a
heater, boiler, kiln or furnace can benefit from them, combustion analyzers are most useful for HVAC professionals or technicians in larger facilities subject to high fuel costs and EPA regulations
which set specific standards for certain emissions that are harmful to the environment.
Combustion analyzers are ideal for setting up and commissioning complex multi-stage, or modulating heating systems as well as basic testing and tuning of all types of boilers, heater or furnaces.
Combustion Analyzer Technology
Since improving combustion can be simplified to burning fuel completely and minimizing harmful emissions, combustion analyzers use an array of sensors, usually packaged in a portable instrument for
use in the field, that quickly and accurately provide the information required to improve combustion. An attached probe permits easy insertion into the exhaust where measurements are made.
Though there is some difference between models as to which sensors are included, most combustion analyzers include a thermocouple, pressure sensors, O2 sensor, and CO sensor. In addition,
since different fuels have different characteristics when analyzed, most models include pre-set fuel profiles.
The sensors included in combustion analyzers provide a number of direct measurements as well as the ability to calculate other rates.
Common Measurements of Combustion Analyzers:
Oxygen (O2): When oxygen appears in flue gas it's a sign more air was supplied than necessary for combustion.
Carbon monoxide (CO): Carbon monoxide in the exhaust gas is a sign of incomplete combustion due to inadequate air supply. Ample oxygen will combine with CO to produce CO2.
Inlet Temperature: Inlet temperatures indicate the amount of heat entering the system by supply air. When determining heat loss, inlet temperatures are compared to flue temperatures
providing net heating information.
Flue Temperature: High flue temperatures reveal heat loss. While some heat loss is unavoidable, the lost heat is a major cause of lower fuel efficiency.
Draft: Draft is the rate at which exhaust gas is vented away as measured by pressure sensors. Excessive draft can prevent heat transfer to the system while inadequate draft allows
water vapor and harmful gases to accumulate.
Efficiency: Combustion efficiency is a calculated measurement of how effectively fuel is converted into heat.
Carbon dioxide (CO2: Carbon dioxide values are calculated from O2and CO measurements. CO2 along with water vapor, should be the only gases present
if combustion is stoichiometric.
Excess Air: A calculated value of the amount of air above what is required for complete combustion. Too much excess air can absorb heat resulting in lower system efficiency.
In addition to the sensors included within the instrument, combustion analyzers often include a number of additional features designed to improve the user experience or to increase the versatility
of the instrument. Some types of additional features include printers, data loggers, communications, toxic gas sensors, and others.
Things to Consider When Selecting a Combustion Analyzer
- What measurement parameters are required?
- Which fuel is being used?
- Are communications needed to send information to a computer or other device?
- Is printing or data logging the information needed?
If you have any questions regarding combustion meters please don't hesitate to speak with one of our engineers by e-mailing us at sales@instrumart.com or calling 1-800-884-4967.
