System requirements and optimization of multi-chillers district cooling plants

Abstract

District cooling systems (DCS) are particularly important in the Middle East due to higher overall temperatures on most days of the year. The design, operation, and control of a new DCS should consider the abundant stakeholders and system requirements transformation using the system engineering processes. Integrating these requirements at an early stage in the system model is essential, specifically, the regulation on energy efficiency or system reliability; without such integration, the system may miss some important aspects and lead to higher energy consumption, lower reliability, higher system cost, greater CO2 emissions and may not satisfy cooling demand of the stakeholders. In this paper, a framework for DCS analysis is proposed by considering inputs, process (core), and outputs. The framework considers the structure and behavior of the DCS system to enhance system design and operation. The core of the framework uses a mathematical model in mixed-integer linear programming (MILP) to optimize the overall DCS cost by integrating the system and stakeholders' requirements. The results obtained from the application of the framework show that addressing the requirements reduces cost and increases energy efficiency, and when the cooling demand is variable, it might be better to have multiple capacities for chillers and chiller storage. The paper is helpful for the decision-makers to understand the impact of requirements and their management in the design, operation, and control of multi-chiller DCS in relief with the cost and energy efficiency. 2022 Elsevier Ltd