(192d) CFD Simulations of Propane/Natural Gas Blended Fuels Combustion in Gas Turbine

Changes to the US electricity industry are forcing a paradigm shift in how the nation's generating assets are operated. Coal-fired power plants optimized as baseload resources are being increasingly relied on as load-following resources to support electricity generated from intermittent renewable capacity. Existing plants are being operated in ways that are suboptimal from the perspective of efficiency and capacity utilization. In an effort to address these challenges by identifying and developing technologies that increase coal-fired power plant efficiency, improve unit reliability and availability, and enhance unit capability for flexible operations (e.g. “cycling”), a CFD model is developed to simulate the propane/natural gas blend combustion rig.

Unconventional gas supplies, like shale gas, are expected to grow which will make U.S. natural gas composition more variable and the composition of fuel sources may vary significantly from existing domestic natural gas supplies. The effect of gas composition on combustion behavior is of interest to allow end-use equipment to accommodate the widest possible gas composition. The CFD model is first validated with the available experimental data which have been collected from a pressurized single injector combustion test rig at the National Energy Technology Laboratory (NETL). The tests are conducted at 7.5 atm with a 589K air preheat. A propane blending facility is used to vary the site natural gas composition. The CFD model predicted results are within the experimental error bar. After the CFD model is validated with experimental results, then a much wider range of gas composition is simulated and the effect of gas composition on combustion is analyzed and discussed.