Table of Contents
What is the function of O2 analyzer?
An oxygen analyzer for stack gas measures the content of oxygen in the exhaust gas after combustion. It provides data to help control the fuel-air ratio in the combustion process. The fuel-air ratio in the combustion process is crucial when optimizing combustion and boiler efficiency.
How do you measure oxygen in a boiler?
Oxygen is measured by using the Oxygen Analyzer at the inlet of Air preheater as well as at the outlet of air heater in the flue gas path. Analyzers installed at inlet of air preheater are used for excess air control and analyzers installed at outlet of air heater are used for assessment of air heater leakage.
Why is the percentage excess oxygen used in a combustion boiler?
The excess air results in oxygen that isn’t consumed during combustion, and this oxygen absorbs otherwise usable heat and carries it out of the stack. The chemically ideal amount of air entering a furnace is just enough for all the oxygen in the air to be consumed. Too much excess air leads to lower flame temperature.
What is O2 trim on a boiler?
An O2 trim system measures the amount of O2 in the exhaust gas stream and provides feedback to automatically position the air damper to the proper position to maintain a set point of excess air. For the most part, boilers that operate with minimal excess air are more efficient.
How does an oxygen analyzer work?
The air being measured for oxygen is filtered by passing it through a diffuser before. Then it is passed through the two chambers. One chamber attracts oxygen via its magnetic field, while the other chamber attracts air. Oxygen alone conducts heat differently than air, and so the temperature in each wire is different.
What should flue gas Analyser readings be?
Flue gas analysers usually display a CO/CO2 ratio. This shows the ratio of carbon monoxide and carbon dioxide in the exit flue (chimney) of the appliance. Generally when this level is below 0.004 the boiler is considered to be running efficiently. For oil or coal fired appliances the CO should not be above 200ppm.
What is oxygen control?
NALFLEET™ Oxygen Control™ is a catalysed liquid hydrazine oxygen scavenger for boiler corrosion protection and treatment. NALFLEET™ Oxygen Control™ provides the required conditions for the establishment of a passivating layer (magnetite) in the boiler.
What is excess O2?
The excess oxygen is the amount of oxygen in the incoming air not used during combustion and is related to percentage excess air. For example, 15\% excess air equals 3\% oxygen while firing natural gas. EXCESS AIR VS EXCESS OXYGEN (O2)
What is combustion efficiency of boiler?
Combustion efficiency is a measure of how effectively the heat content of a fuel is transferred into usable heat. An often-stated rule of thumb is that boiler efficiency can be increased by 1\% for each 15\% reduction in excess air or 40°F reduction in stack gas temperature.
Does analyser work principle?
Electrochemical dissolved oxygen sensor working principle: In an electrochemical DO sensor, dissolved oxygen diffuses from the sample across an oxygen permeable membrane and into the sensor. Once inside the sensor, the oxygen undergoes a chemical reduction reaction, which produces an electrical signal.
How does an analyser work?
An analyser or analyzer is a tool used to analyze data. For example, a gas analyzer tool is used to analyze gases. It examines the given data and tries to find patterns and relationships. An analyser can be a piece of hardware or software.