The present study assesses life cycle CO2 (LCCO2) reduction costs of ocean thermal energy conversion (OTEC) systems with combined use of deep sea water by area considering the natural and social conditions in different areas of Japan. This study considers sea surface temperature, climate, region scale, type of grid power and location as regional conditions. The assessment reveals that the LCCO2 reduction cost greatly varies from 860 to 323,000 [JPY/t-CO2] depending on the areas. Areas where LCCO2 reduction costs are less than 30,000 [JPY/t-CO2] are the medium and large scale remote islands of Okinawa, the Okinawa main island, the largescale remote islands of Kyushu, and the large-scale remote islands of Shikoku, where the installation of OTEC systems are promising. There are the two main reasons for the small LCCO2 reduction costs in these areas; first, the amount of power generation is large because of the low latitude. Second, the effect of combined use of deep sea water is large because these areas have large cooling demand due to the low latitude or the large regional scale.
To evaluate characteristics of the Flamelet/Progress-Variable approach (FPV) and Flamelet-Generated Manifolds method which can consider a detailed chemical reaction mechanism, a combustion simulation was performed in a laminar counter-flow diffusion flame. While the numerical solutions of the FPV reproduced the measurements and almost completely agreed with those of the detailed chemical reaction mechanism, the numerical solutions of the FGM method overpredicted the measurements of CO mole fraction and underpredicted the ones of CO2 especially in fuel-rich region, and differed from those of the detailed chemical reaction mechanism. This is because the flamelet table of the FGM indicates the state close to chemical equilibrium and overpredicts dissociation of CO2 when the combustion reaction sufficiently progresses.