How to Perform Combustion Tests on Natural Gas Boilers
In this time of concern over global warming and greenhouse gases, it is important to be able to measure the pollutants and particulates being exhausted into the atmosphere. Boilers, including natural gas boilers, exhaust a variety of gases as a normal by-product of their operation. The EPA has mandated that testing be done on a number of these gases--NO, NO2, SO2, H2S, etc.The test methods and parameters of acceptance are very involved and cover many pages of instruction.
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Things You'll Need
- Portable electrochemical analyzer (EC)
- Electric drill
- Thermocouple
- Gas analyzer (optional)
Instructions
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How to Perform Combustion Tests on Natural Gas Boilers
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1
Using a thermocouple probe, measure and record the temperature at the base of the flue at the point of highest exhaust gas temperature.
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2
Locate the area on the boiler stack where the testing is to be done. Select a point at least two stack diameters downstream from any flow disturbances such as bends, restrictions or expansions, and one-half stack diameter upstream from where the gas is discharged into the atmosphere.
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3
Drill a hole at the selected sample point on the boiler stack. The hole should be the same size as the EC probe. Insert the probe into the drilled hole. Try to insure that no flue gas escapes around the probe.
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4
Take flue gas readings every 30 seconds for 5 minutes during the "ramp-up phase." Record readings for the gas samples, sample flow rate and temperature.
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5
Take flue gas readings every 15 seconds for 2 minutes in the "test data phase." Again, record the readings for the gas samples, sample flow rate and temperature. Use the "test data phase" information accumulated in each run to calculate an average concentration for each gas tested.
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6
Take flue gas readings for eight minutes in the "refresh phase" (or until the manufacturer's specifications indicate that the EC is "refreshed.") Record the readings for the gas samples, sample flow rate and temperature.
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Tips & Warnings
Use a gas analyzer with a built-in printer and data-logging feature to assist in good record-keeping. Use a gas analyzer with a heated probe and heated sample line to reduce moisture condensation in the flue gas.
