Assessment of the feasibility for hybrid seawater district cooling model under variable seawater temperature condition: Case study in South Korea

In this study, a hybrid seawater district cooling model consisting of free cooling, seawater-assisted turbo chiller, and district heating assisted absorption chiller was presented and the sustainability of the model was assessed in terms of market competitiveness. An in-house developed operational simulation tool was used to compare and analyze the impact on operating performance of seawater temperature conditions, either constant or variable, throughout the year. The decision-support operation simulation tool, adopted in this study, was developed based on relational database technology to support the planning, or design of district cooling system, and, compared to other optimization methods such as Mixed Integer Linear Programing, it is relatively simple but more intuitive in the way it supports user's design. From the comparative analysis, it was estimated that approximately 30% higher primary energy saving benefit could be achieved under constant seawater temperature conditions. However, it was also evaluated to still achieve a primary energy saving advantage of around 50% under variable seawater temperature conditions with significant investment cost savings for water intake and heat exchanger installation, confirming it as a feasible alternative to achieve techno-economic competitiveness.