The amount of oxygen in the flue gas of a boiler indicates how much excess air is in the flue gas mixture. The lower the amount of excess air, the higher the boiler efficiency. In other words, the higher the amount of oxygen, your boiler becomes less efficient and more expensive to operate. According to Carbon Trust, the air to fuel ratio is one of the main factors affecting boiler efficiency. The technology of air to fuel ratio is set during commissioning and over time this tends to drift due to the changes in the fuels calorific value, combustion air temperature and control electronics. As a result of this, the boiler uses more energy to burn more fuel, causing increased emissions and increased costs.
Oxygen trim systems overcome these issues. If you have a large, continuously operating boiler plant, you are likely to save at least 5% and recoup your costs within 2 years. The oxygen sensor is inserted directly into the boiler flue which is connected to a control panel that continuously monitors the oxygen concentration enabling complete control over the boilers air to fuel ratio. Meaning that factors influencing drift within the boilers environment such as barometric pressure and high temperature do not force the boiler to run less efficiently that it is capable of.
Zirconium Dioxide Oxygen Sensors are the most common type of sensor used in this field and the sensors from SST have been used reliably in boiler exhaust gases for over 25 years. The full pourus stainless steel cap allows free flow of the flue gases to reach the sensor while trapping any soot or debris which might otherwise lead to sensor malfunction. SST’s sensors will last for years even in badly regulated combustion processes before the dirt and pollution has any effect.
Why Use SST’s Zirconia Oxygen Trim Systems?
- Proven track record, very robust sensor with many years of operation in boiler exhaust gas
- Highly accurate in aggressive, high temperature environment
- Single point calibration with no reference gas required
- Supplied with or without control electronics
To be cost effective, oxygen trim control systems are really designed for large boilers of over 500kW of output. They can work with natural gas, LPG, oil-fired and dual fuel bruners.
For more information on SST’s Zirconia Oxygen Sensor Systems, please Ask Our Sensor Experts Today!for their advice.