Abstract
Small and medium size gas turbines are widely used for distributed power and combined heat and power. However, most have power generation efficiency of less than 35% because of the simple cycle. A chemically recuperated gas turbine (CRGT) has an advanced cycle, which recovers exhaust heat by endothermic reaction converting fuel into hydrogen-rich gas. Several papers report that the results of feasibility studies indicate CRGT would be effective for improving power generation efficiency of the simple cycle GT. Also, the CRGT using methanol steam reforming has been demonstrated, but the components and system operation have not been assessed technically in the case of natural gas. In order to realize the CRGT with natural gas steam reforming, we applied the CR system to a commercial 4MW simple cycle GT and examined the static mass and heat balance by process simulator. We designed a reformer consisting of tube bundles by numerical analysis, which considered mass and heat transfer and chemical reaction in the catalyst bed and clarified the master plan figure of the heat recovery system. Also, the reformer was structurally analyzed using FEM and the stresses due to internal pressure, gravity and temperature distribution were calculated and the stresses in the cross section under severe condition were evaluated with ASME code. This paper presents the results and discussions of these studies.
