SIMULATION OF CO_2 RECOVERING CLOSED GAS TURBINE WITH CH_4-O_2 FIRING

摘要

The oxidation process of unburned species such as CO and H_2 are numerically investigated to estimate the emission characteristics from CO_2 recovering closed gas turbine system with CH_4-O_2 firing. And the total system performance of the turbine system including the O_2 manufacturing power is also estimated. The computational results are summarized as follows: 1. To suppress the CO concentration at turbine outlet, equivalence ratio should be controlled less than about 0.95. 2. Locally high temperature area causes the increasing of CO concentration. 3. At the low equivalence ratio, locally high-concentration unburned species such as CO and H_2 are rapidly oxidized in the early stage of expansion process in the turbine. 4. System efficiency depends on the condenser performance in operation at low equivalence ratio. 5. System efficiency is strongly affected by the O_2 manufacturing power. Decrease of efficiency is about 10 % with current O_2 manufacturing plant.