“Compact gas heater/mixer for special applications: theoretical approach and experimental verification"

A particular double fluid and phase transition heat exchanger and gas mixer characterized by a linear shape is here proposed and studied. The system may be used for special applications where must be achieved. The exchanger was firstly proposed for feeding molten carbonate fuel cell (MCFC) patented (patent n°: PO 2003 A 0019) by researchers of the University of Perugia. Because of the small size and compact geometry of patented MCFC stack, a custom system for natural gas and water introduction is required: a natural gas must be heated (stack temperature is 650°C) and mixed with steam in order to get gas reforming into hydrogen and meanwhile anodic humidification which is required to extend MCFC life [1]. Theoretical results were verified by experimental investigations. The proposed heat exchanger design approach may be applied to any devices which requires high temperatures feeding gases, such as any fuel cell type or reforming industrial plants.