Combustion Modeling for Direct Fired Supercritical CO2 Power Cycles
- Combustion Research and Flow Technology, Inc., Pipersville, PA (United States)
Supercritical CO2 (sCO2) power cycles are gaining interest across a variety of applications due to the potential for significant efficiency improvements and reduced plant sizes. However, system design based on these cycles presents many challenges. These challenges include: 1) compressor design with inlet conditions close to the critical point, and 2) combustor design at supercritical conditions. Computational tools will be required to address these challenges and supplement experimental data to support design trade studies. Regarding the combustor, operating pressures are such that the chemical kinetics are not well understood. At pressures of 200-300 atm and with high CO2 dilution, the combustor conditions are beyond the range of current experience and validity of chemical models for computational studies. Due to high fluid densities, Reynolds numbers are very high which leads to uncertainty with regard to the flame regime of the combustor. This poses difficulties for turbulent combustion modeling since many models assume a particular flame regime to develop tractable models for design applications. To computationally capture the high Reynolds number flows characteristic of sCO2 power cycle combustors will require advanced simulation approaches such as Reynold Average Navier-Stokes (RANS) and large-eddy simulation (LES) methods. These methods offer the most viable long term approach for accurately capturing the high Reynolds number and highly unsteady flows associated with these combustors. Both the RANS and LES equations of motion require modeling for the effect of turbulent flame interactions that appear as unclosed terms within these equations. Accurate turbulent combustion models are required to account for these interactions. A range of turbulent combustion models for gas phase combustion is available. These models are based on a variety of differing assumptions that restrict their range of applicability. With this in mind, the primary objective of this SBIR program was to develop a tractable turbulent combustion modeling approach that may be applied to design trade studies of sCO2 power cycle combustors. Under this Phase I program a unique combustion modeling approach for application to direct fired sCO2 power cycle combustors was developed. This formulation is based on an energy conserving form of the direct quadrature method of moments (DQMOM) combustion model that has, for the first time, been extended for reacting flow, real fluid applications. This modeling formulation provides a comprehensive description of micro-scale combustion processes occurring within the flow as modeled directly with a probability density function (pdf) transport equation mixing model. Though comprehensive, the new formulation is computationally tractable DOE-CRAFTTech- SC0017235 iv CRAFTR-11.2017.023 Combustion Research and Flow Technology, Inc. (CRAFT Tech) for routine application to design trade studied as applied within Reynolds Average Navier-Stokes (RANS) or large-eddy simulation (LES) flow modeling. Computational efficiency has been achieved by casting the model equations within an Eulerian solution procedure instead of a Monte Carlo procedure that is typically employed with pdf transport models. This project has provided for the initial verification of the model implementation and a preliminary demonstration of the model’s application to representative sCO2 combustor conditions. The Phase II program may now focus on the validation of the modeling approach with respect to experimental data for specific sCO2 combustor configurations.
- Research Organization:
- Combustion Research and Flow Technology, Inc., Pipersville, PA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- SC0017235
- OSTI ID:
- 1411010
- Type / Phase:
- SBIR (Phase I)
- Report Number(s):
- DOE-CRAFTTech-SC0017235
- Country of Publication:
- United States
- Language:
- English
Similar Records
A Novel In Situ Flamelet Tabulation Methodology for the Representative Interactive Flamelet Model
LES SOFTWARE FOR THE DESIGN OF LOW EMISSION COMBUSTION SYSTEMS FOR VISION 21 PLANTS