Summer period analysis of the rotary desiccant - hybrid cooling system combined with solid oxide fuel cells using human waste fuel

Abstract

This paper proposes and simulates a desiccant air cooling system integrated with a vapor compression cooling unit and a heat recovery unit for an office building in Çanakkale, Turkey, during the summer season. The required electrical energy for equipment of the proposed system is supplied by an Solid Oxide Fuel Cells (SOFC) unit using human waste as fuel. Moreover, some of the waste heat generated by the SOFC is used to regenerate the desiccant wheel. The simulation also includes the effects of three different refrigerants for the vapor compression cooling unit. Among the refrigerants, the highest electrical COP was obtained for the system using R1234ze(Z), which is 3.14% and 2.40% higher than the systems using R717 and R1233zd(E), respectively. Additionally, the system using R1234ze(Z) achieved electrical savings of 9.97% and 9.23% compared to the other systems. These electrical savings resulted in fuel savings of 1.19% and 0.90% for R1234ze(Z) compared to R717 and R1233zd(E), respectively. During the summer season, the electricity production from the existing SOFC unit met 82.00% of the total electricity consumption of the desiccant hybrid cooling system. Furthermore, a difference of 3984.56 kWh in primary energy consumption was identified between the desiccant hybrid cooling systems operating with the SOFC and without the SOFC during the summer season.

Keywords

• Desiccant wheel
• Vapor compression cooling
• Solid oxide fuel cells
• Human waste
• Biomass
• Refrigerants