Design and commissioning of a pilot-scale staged, pressurized oxy-combustion system

摘要

Concerns over the greenhouse gas emissions from coal-based power generation have led to several efforts towards new generations of coal combustion technologies for CO_2 mitigation, including staged, pressurized oxy-combustion (SPOC), a unique process that burns coal in high oxygen-concentration and pressurized environment. As determined through process analyses, the SPOC process increases the net plant efficiency by more than 6 percentage points, compared to first-generation oxy-combustion plants. The SPOC boiler design features a co-axial, low mixing flow with no external recirculation, which is completely different from conventional coal-fired boilers. The demonstration of this boiler design is critical for the commercialization of the SPOC technology. Although computational fluid dynamics (CFD) simulations have showed that this design can create a relatively uniform radiative heat flux on the wall, and minimized ash deposition, experimental studies are still needed to demonstrate the performance of the boiler, and also to validate the model. In this work, we introduce the design and commissioning of our 0.1 MW_(th) pressurized oxy-combustion facility. The facility can operate at a pressure up to 20 bar and thermal input up to 0.1 MWth, and is designed to accommodate a wide variety of gas inlet conditions to simulate various stages of the SPOC process. Preliminary experiment results demonstrated that most of the design goals were achieved with the current boiler design. More tests have been scheduled to further demonstrate the design and study the combustion characteristics of coal under SPOC conditions.