Abstract
A gas dynamic laser (GDL) is a promising technology that can generate high laser power driven directly by combustion energy. When a gas containing carbon dioxide at high temperature and high pressure is expanded adiabatically through a supersonic nozzle, the population inversion between the two vibrational energy levels, (001) and (100) of carbon dioxide molecules can be achieved. Then it leads to emit a laser power of wavelength 10.6 micrometer. In the present study, a tri-generation system applying GDL is proposed. Figure 1 shows schematic diagram of the tri-generation system. The tri-generation system is a system combined by photo energy conversion and conventional co-generation, i.e. electric power generation and heat energy utilization from fuels. As the first step for R&D of this system, the fundamental study on the GDL working in pressurized combustion of a methane-air mixture was carried out. The combustor consists of triple annular tubes, whose inner annular zone is pressurized by nitrogen so to balance to the pressure in the combustion zone and is cooled down by water flowing in the outer annular zone. Combustion takes place above a ceramic honeycomb placed in the inner tube of 100.1 mm ?in diameter. Compressed air and methane are supplied independently from the bottom of a bed of (glass beads (2, 5, 8mm)). A supersonic laver nozzle designed at Mach 4.7 was assembled in the downward of the combustor. A condition necessary for the ignition and a stable flammability region were examined in the combustor by temperatures and the combustion gas composition. The supersonic flow through the nozzle was confirmed from the pressure distribution.