By Pass System
Carbon Monoxide Control Solution
What it offers
When gas turbines work in part-load conditions, combustion is incomplete that translates into an increase in CO emission. The main origins of CO emissions are one or more of the following:
- Inadequate burning rate due to a fuel/air ratio that is too low and/or insufficient residence time,
- Inadequate mixing of fuel and air, which produces some regions in which the mixture is too lean to support combustion, while in some others over-rich combustion yields high local CO concentrations,
- Quenching of the post-flame products by entrainment into the liner wall-cooling air.
In principle, it should be possible to reduce the CO formed in primary combustion to a very low level by the staged admission of additional air downstream to achieve lower CO emissions. In practice, to achieve lower CO emissions at part load, a combustor bypass system is available as an option. The purpose of this system is to ensure complete combustion and therefore minimize the CO emissions and increase the efficiency during part load operation in the SGT-600 gas turbine.
A glimpse into the design
The bypass system is integrated into the turbine casing. The system consists of 6 valves controlled by one actuator. Opening of the bypass valves means that the airflow to the burners decreases, the flame temperature increases and the CO emissions declines. The bypass system keeps the flame temperature and the emission levels constant at part load. It keeps the flame temperature and the emission levels constant at 70% to 100% of loading.
Benefits
Carbon Monoxide (CO) is a toxic gas and a principal gas turbine combustion by-product, especially at part load. CO reduces the capacity of the blood to absorb oxygen, and in high concentrations, can cause asphyxiation and even death. To achieve lower CO emissions at part load, a combustor bypass system is available as an option. The bypass system is integrated into the turbine casing. The system consists of 6 valves controlled by one actuator.
The main customer benefits include:
- Decreasing CO emission at part load from 600 ppm to 100 ppm
- Increasing flame stability and turbine availability
