Analytical Study of Tri-Generation System Integrated with Thermal Management Using HT-PEMFC Stack

Abstract

Recently, extensive studies on power generation using clean energy have been conducted to reduce air pollution and global warming. In particular, as existing internal combustion engines lose favor to power generation through hydrogen fuel cells, the development of tri-generation technology using efficient and reliable fuel cells is gaining importance. This study proposes a tri-generation thermal management model that enables thermal control and waste heat utilization control of a high-temperature PEMFC stack that simultaneously satisfies combined cooling, heating, and power (CCHP) load. As the high-temperature PEMFC stack operates at 150 °C or more, a tri-generative system using such a stack requires a thermal management system that can maintain the operating temperature of the stack and utilize the stack waste heat. Thus, to apply the waste heat produced through the stack to heating (hot water) and absorption cooling, proper distribution control of the thermal management fluid (cooling fluid) of the stack is essential. For the thermal management fluid control design, system analysis modeling was performed to selectively design the heat exchange amount of each part utilizing the stack waste heat. In addition, a thermal management system based on thermal storage was constructed for complementary waste heat utilization and active stack cooling control. Through a coupled analysis of the stack thermal management model and the absorption cooling system model, this study compared changes in system performance by cooling cycle operation conditions. This study investigated into the appropriate operating conditions for cooling operation in a tri-generative system using a high-temperature PEMFC stack.

Keywords

• combined cooling heating and power system
• Tri-generation
• high temperature proton exchange membrane fuel cell (HT-PEMFC)
• water/lithium bromide absorption chiller