Design and investment strategy optimization of district cooling system during the ramp-up phase

Abstract

District Cooling (DC) systems, known for their efficiency and integration of renewable energy sources, encounter substantial design and investment complexities during the initial ramp-up phase. This critical phase is characterized by increasing cooling demand, necessitating a scientific approach to equipment selection and sizing that spans multiple temporal scales. A key yet frequently underestimated element in DC systems is the inclusion of backup chiller. While traditionally reserved to emergency use, its proactive interactions with regular system operations can significantly diminish operational expenses, despite the inherent complexities. Our study presents an innovative mixed-integer linear programming (MILP) optimization framework. This framework is designed to manage and optimize the intricate DC system design and investment strategy during the ramp-up phase, with a particular focus on the strategic inclusion of backup chillers. To demonstrate this framework, our research undertakes a comprehensive analysis of a real-world DC project in Kuala Lumpur. The findings show that the MILP optimization delivers substantial reductions in Life Cycle Costs (LCC) up to 3.33% across various system configurations. This is of significant value for energy efficiency and sustainable urban energy systems.