No abstract

Since 2004, stationary SOFC CHP systems using flatten tubular segmented-in-series (FT-SIS) cell stacks have been developed by Tokyo Gas Co., Ltd., Gastar Co., Ltd., Rinnai Corporation and Kyocera Corporation to construct small-scale CHP systems which excel in performance and durability. In 2008, we succeeded in producing a residential system which consists of a power generation unit using FT-SIS cell stacks and a heat recovery unit. Electric power and hot water are produced efficiently in the system, and by adopting electric load following operation, the produced energy is supplied to the residence with minimal loss. Since 2009, we have installed these systems into residences to collect operation data under practical use conditions. A part of the tests are conducted under NEDO SOFC Demonstration Program. From the operational data, environmentally-enhancing potentials and superior durability of the FT-SIS SOFC systems are verified.

In this paper we present recent results of developments for segmented-in-series SOFCs at Tokyo gas. We have been developing segmented-in-series SOFCs for several years. The segmented-cell is a unique idea of eliminating the cell stacking process in assembling processes. For high performance of an SOFC system with the segmented-cells, the cell configuration must be designed optimally and a DC module must be devised to draw the potential of the segmented-cell. In addition, to obtain higher conversion efficiency for the AC system using the segmented-cells, the DC/AC conversion efficiency of the power conditioner should be improved and the energy consumption of the BOP must be reduced. By improving the DC module, developing the power conditioner with a high DC/AC conversion efficiency and reducing the BOP loss, the high net conversion efficiency of the system was achieve

Severa上important sublects on developing SOFC system were studied ． Temperature distribu 七ions at a cell module ， distributions of air or fuel supplying to cells ， and an elec 七 rically series or parallel connection of cells are key issues． The effec 七s of 七 hese parameters on the conversion efficiency