TECHNOLOGY UPDATE ON GAS TURBINE DUAL FUEL, DRY LOW EMISSION COMBUSTION SYSTEMS

摘要

A challenging issue in the gas turbine industry is to develop a practical dual fuel (DF), dry low emission (DLE) combustion system. Especially for the onshore-based power generation systems, and liquid DLE for aeroderivative engines used for marine propulsion. A novel mid-size (3MW) gas turbine is being developed mainly targeted for marine propulsion, where a dual fuel DLE combustion system aiming at single digit NOx emission figures has been explored. As a part of this development, the present technology available from different gas turbine manufacturers has been surveyed. Status of the different techniques applied in dual fuel DLE combustors today and their achievements are presented, including the available information on fuel injectors, cooling schemes, combustion air distribution, noise control and combustor performance. The techniques utilized and explained are such as flame temperature control (water/steam injection), staged combustion, lean premixing and lean prevaporized premixing, rich-quench-lean-burning (RQLB) and catalytic combustion. These are also documented for the different concepts commercially available, describing both advantages and drawbacks. Conclusions are made towards the dominating trends for the different parameters mentioned above, and how they affect the final combustor design. A survey of the dominating parameters for low emission combustion systems is presented.