Developing Statistical Evaluation Model of Introduction Effect of MSW Thermal Recycling
ABSTRACT For the effective utilization of municipal solid waste (MSW) through a thermal recycling, new technologies, such as an incineration plant using a Molten Carbonate Fuel Cell (MCFC), are being developed. The impact of new technologies should be evaluated statistically for various municipalities, so that the target of technological development or potential cost reduction due to the increased cumulative number of installed system can be discussed. For this purpose, we developed a model for discussing the impact of new technologies, where a statistical mesh data set was utilized to estimate the heat demand around the incineration plant. This paper examines a case study by using a developed model, where a conventional type and a MCFC type MSW incineration plant is compared in terms of the reduction in primary energy and the revenue by both electricity and heat supply. Based on the difference in annual revenue, we calculate the allowable investment in MCFC-type MSW incineration plant in addition to conventional plant. The results suggest that allowable investment can be about 30 millions yen/(t/day) in small municipalities, while it is only 10 millions yen/(t/day) in large municipalities. The sensitive analysis shows the model can be useful for discussing the difference of impact of material recycling of plastics on thermal recycling technologies.
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ABSTRACT: A formulation of the approximate deconvolution model (ADM) for the large-eddy simulation of flows in complex geometries is detailed and applied to compressible turbulent flows. The paper considers two different issues. First, we study the feasibility of low-order schemes with ADM for large-eddy simulation. As test case compressible decaying isotropic turbulence is considered. Results obtained with low-order finite difference schemes and a pseudospectral scheme are compared with filtered well-resolved direct numerical simulation (DNS) data. It is found that even for low-order schemes very good results can be obtained if the cutoff wavenumber of the filter is adjusted to the modified wavenumber of the differentiation scheme. Second, we consider the application of ADM to large-eddy simulation of the turbulent supersonic boundary layer along a compression ramp, which exhibits considerable physical complexity due to the interaction of shock, separation, and turbulence in an ambient inhomogeneous shear flow. The results compare very well with filtered DNS data and the filtered shock solution is correctly predicted by the ADM procedure, demonstrating that turbulent and non-turbulent subgrid-scales are properly modeled. We found that a computationally expensive shock-capturing technique as used in the DNS was not necessary for stable integration with the LES.12/2003: pages 33-47;